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Periodontally diseased tooth roots used for lateral alveolar ridge augmentation. A proof-of-concept study
Abstract
Objectives:
To assess the efficacy of periodontally diseased tooth roots used as autografts for lateral ridge augmentation and two-stage early osseointegration of titanium implants.
Material & methods:
Ligature-induced periodontitis lesions were established at the maxillary premolars in n=8 foxhounds. Extracted, scaled and root planned premolar roots (PM-P) as well as retromolar cortical autogenous bone (AB) blocks were used for horizontal ridge augmentation of mandibular chronic-type defects. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Histological analyses included crestal ridge width - CW; augmented area - AA and bone-to-implant contact - BIC.
Results:
Both PM-P and AB grafts were gradually organized and replaced by newly formed bone. Median CW (PM-P: 3.83 vs. AB: 3.67 mm), AA (PM-P: 10.18 vs. AB: 9.82 mm(2) ) and BIC (PM-P: 50.00 vs. AB: 35.21%) values did not reach statistical significance between groups (p>0.05, respectively). Histologically, PM-P grafts were not associated with any inflammatory cell infiltrates.
Conclusions:
PM-P autografts may reveal a structural and biological potential to serve as an alternative autograft to AB. This article is protected by copyright. All rights reserved.
... The osteoconductive and inductive properties of dentin, which can promote bone formation at grafted defect sites, have been demonstrated in several animals and human clinical studies [4,[8][9][10][11][12][13][14]. There is significantly less resorption of the graft compared to autogenous bone graftse.g., monocortical bone block grafts from the retromolar region [15][16][17][18]. Other outcome measures based on histological, immunohistochemical, and radiologic evaluations did not show significant differences between dentin and bone grafts [19,20]. ...
... There is histological evidence that grafts derived from autogenous tooth material are involved in bone remodeling processes and allow sufficient osseointegration of dental implants [15,21,22]. Even though teeth that were in contact with the oral cavity were used for grafting, no increased inflammation could be observed histologically [16] and there was no increased level of wound infections or loss of grafts [23]. ...
... Recent research has shown that autogenous dentin shares many similarities with bone in its structural and chemical compositions and is, therefore, suitable as a bone substitution material with comparable biological properties and less resorption of the graft [17,18]. Autogenous dentin, however, has been shown to be involved in the remodeling process of bone and to be successively replaced by newly formed bone through replacement resorption more homogenously than bone grafts but leaving some remnants of the tooth material [16]. Partial demineralization of the dentin, which was performed by a 10% EDTA solution in this study, is able to promote the replacement resorption and new bone formation due to the exposure of the collagen network and the release of osteogenic growth factors-e.g., bone morphogenetic proteins. ...
In the literature, autogenous dentin is considered a possible alternative to bone substitute materials and autologous bone for certain indications. The aim of this proof-of-concept study was to use autogenous dentin for lateral ridge augmentation. In the present retrospective study, autogenous dentin slices were obtained from teeth and used for the reconstruction of lateral ridge defects (tooth-shell technique (TST): 28 patients (15 females, 13 males) with 34 regions and 38 implants). The bone-shell technique (BST) according to Khoury (31 patients (16 females, 15 males) with 32 regions and 41 implants) on autogenous bone served as the control. Implants were placed simultaneously in both cases. Follow-up was made 3 months after implantation. Target parameters during this period were clinical complications, horizontal hard tissue loss, osseointegration, and integrity of the buccal lamella. The prosthetic restoration with a fixed denture was carried out after 5 months. The total observation period was 5 months. A total of seven complications occurred. Of these, three implants were affected by wound dehiscences (TST: 1, BST: 2) and four by inflammations (TST: 0, BST: 4). There were no significant differences between the two groups in terms of the total number of complications. One implant with TST exhibited a horizontal hard tissue loss of 1 mm and one with BST of 0.5 mm. Other implants were not affected by hard tissue loss. There were no significant differences between the two groups. Integrity of the buccal lamella was preserved in all implants. All implants were completely osseointegrated in TST and BST. All implants could be prosthetically restored with a fixed denture 5 months after augmentation. TST showed results comparable to those of the BST. Dentin can therefore serve as an alternative material to avoid bone harvesting procedures and thus reduce postoperative discomfort of patients.
... 1 For several years, the use of dentin as an alternative autogenous material for alveolar crest reconstruction and the grafting of bone deficits has been described and investigated in animal experiments and clinical studies. [2][3][4][5][6][7][8][9][10][11] Dentin is a suitable grafting material because it is very similar to bone in its organic and inorganic composition. Similar to the alveolar bone, about 90% of the organic substance of dentin consists of type I collagen. ...
... Histologically, animal experiments showed a substitutive resorption of the dentin and a contact area between implant and bone which was comparable to autogenous bone blocks. 2,8 In the region of direct contact between dentin and titanium implant surface, the formation of root cementum and mineralized hard tissue could be identified histologically. [25][26][27] Furthermore, the preparation of the tooth also seems to have an influence on the success rate. ...
... 30 In animal experiments, however a slightly higher incidence of augmentation material exposure was observed if teeth were used that had been endodontically treated or was periodontally compromised in comparison with healthy retained teeth that were not exposed to the oral cavity environment. 7,8 But in a clinical study published by Schwarz et al. in 2019, this observation was not confirmed. In the Schwarz study, neither impaired wound healing nor dehiscences were found for the healthy retained as well as for the endodontically treated and/or periodontically compromised teeth. ...
Background
Autogenous bone block graft is considered the gold standard for lateral defects. Dentin has been identified to be a suitable autogenous bone graft material due to its structural and chemical similarities to the alveolar bone.
Methods
This proof of concept study describes the clinical application of the tooth shell technique in 24 sites with 27 implants of 22 patients. A tooth shell was fixed laterally to the defect with microscrews. Distance between the shell and the residual bone was filled with particulate remnants of the tooth root. Implant was inserted simultaneously. Cone beam computed tomography were done after implant insertion (T1) and three months later (T2). Target parameters were biological complications and the resorption of bone graft.
Results
Even though a graft exposure occurred in one case (4,5% on patient‐level), all implants showed enough implant stability and were able to be loaded. At T2 the evaluation of the X‐rays showed no case with hard tissue loss at the mesial or distal implant shoulder. All implants were completely osseointegrated.
Conclusions
The tooth shell technique showed promising results for the reconstruction of lateral alveolar crest defects. It may be considered to serve as an alternative material to avoid bone harvesting procedures.
... Autologous tooth roots have gained increasing attention for oral bone augmentation [1] and were systematically investigated for lateral augmentation in deficient extraction sockets [2] and ridges prior to implant placement [3]. This clinical concept is based on radiological analyses [4,5], case reports [6,7] and preclinical studies [8][9][10]. These studies support the clinical use of autologous tooth roots and particularly dentine as a graft material for bone augmentation. ...
... This research was motivated by the increasing clinical use of autologous tooth roots for oral bone augmentation [1,2,[4][5][6]. The tooth crown and root dentine, however, may be contaminated by dental plaque, being a rich source of endotoxins [27]. LPS, being the hallmark endotoxin, can then activate the TLR4 -NF-κB signaling cascade that drives the expression of cytokines and other mediators that in turn initiate or even maintain an inflammatory tissue response [18][19][20]. ...
... These teeth are not or only marginally contaminated with plaque, as canines, premolars and molars were also used for preparing block grafts [2,7]. Importantly, periodontally diseased tooth roots were applied for lateral alveolar ridge augmentation, at least in a canine model [6]. Periodontitis promotes host inflammatory mediators from the fibroblasts and macrophages in response to bacteria in the biofilms [15]. ...
Particulate autogenous tooth roots are used for alveolar bone augmentation surgery; however, dental plaque may provoke an inflammatory response that may counteract the desired graft consolidation process. Traditional mechanical cleaning of extracted teeth may be of support to lower a possible inflammatory response of the autograft. To test this assumption, extracted porcine teeth were left either uncleaned or underwent mechanical cleaning with a toothbrush and toothpaste before being fragmented and subjected to acid lysis, termed as unclean acid dentine lysate (ucADL) and clean acid dentine lysate (cADL), respectively. The inflammatory responses of murine macrophage RAW 264.7 cells being exposed to the respective acid dentine lysates were evaluated at the level of inflammatory gene expression and IL6 immunoassays. We report here that acid lysates obtained from uncleaned teeth provoked a robust increase in IL1β, IL6, and COX2 in RAW 264.7 cells. The mechanical removal of dental plaque significantly reduced the inflammatory response. Consistently, Limulus tests revealed that tooth cleaning lowers the presence of endotoxins in dentine lysates. To further prove the involvement of endotoxins, a toll-like receptor 4 (TLR4) inhibitor TAK242 was introduced. TAK242 abolished the inflammatory response provoked by acid lysates obtained from uncleaned teeth in RAW 264.7 cells. Moreover, nuclear translocation and phosphorylation of the TLR4 downstream NFκB-p65 were attenuated at the presence of cleaned versus uncleaned dentine lysates. Taken together, our data support the importance of dental plaque removal of teeth being extracted for alveolar bone augmentation surgery.
... In particular, histological and immunohistochemical analyses indicated that TR grafts were gradually replaced by newly formed bone and resulted in a significant horizontal and vertical bone gain. [3][4][5][6] Second stage implant placement was associated with a comparable formation of a new bone to implant contact (BIC) as noted at AB grafted sites. 3,5 To account for a potential contamination of grafts separated from potentially nonretainable, infected teeth, TR's were autoclaved and proven to exhibit a similar biological potential as nonautoclaved specimens. ...
... [3][4][5][6] Second stage implant placement was associated with a comparable formation of a new bone to implant contact (BIC) as noted at AB grafted sites. 3,5 To account for a potential contamination of grafts separated from potentially nonretainable, infected teeth, TR's were autoclaved and proven to exhibit a similar biological potential as nonautoclaved specimens. 6 Recent microcomputed tomographic (μCT) analyses also focused on the assessment of bone volume per tissue volume (BV/TV), trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp), thus providing a volumetric analysis of TR following lateral ridge augmentation. ...
... 7,8 These differences may mainly be attributed to the rather heterogeneous replacement resorption associated with TR grafts, which has been noted after both later-and vertical alveolar ridge augmentation. 3,5,6 When comparing volumetric μCT with histology, it must be noted that a high agreement has been reported for corresponding 2D sections. 12 Nonetheless, μCT and histology are complementary techniques. ...
Background:
To volumetrically assess the bone microstructure following vertical alveolar ridge augmentation using differently conditioned autogenous tooth roots (TR) and second-stage implant placement.
Materials and methods:
The upper premolars were bilaterally extracted in n = 4 beagle dogs and randomly assigned to either autoclavation (TR-A) or no additional treatment (TR-C). Subsequently, TR were used as block grafts for vertical alveolar ridge augmentation in both lower quadrants. At 12 weeks, titanium implants were inserted and left to heal 3 weeks. Microcomputed tomography was used to quantify bone volume per tissue volume (BV/TV), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp) at vestibular (v) and oral (o) aspects along the implant and in the augmented upper half of the implant, respectively.
Results:
Median BV/TV [TR-C: 51.33% (v) and 70.42% (o) vs TR-A: 44.05% (v) and 64.46% (o)], Tb.th [TR-C: 0.22 mm (v) and 0.27 mm (o) vs TR-A: 0.23 mm (v) and 0.29 mm (o)] and Tb.Sp [TR-C: 0.26 mm (v) and 0.13 mm (o) vs TR-A: 0.29 μm (v) and 0.15 mm (o)] values were comparable in both groups.
Conclusion:
Both TR-C and TR-A grafts were associated with a comparable bone microstructure within the grafted area.
... A recent series of preclinical studies performed in a canine model have demonstrated that extracted tooth roots (TR) may be successfully used as an alternative autograft for lateral alveolar ridge augmentation and two-stage implant placement [4,5]. TR were separated from either healthy, endodontically treated, or periodontally infected premolars and histologically involved in a replacement resorption, thus resulting in a comparable gain in ridge width as autogenous cortical bone blocks (AB) [4][5][6][7]. ...
... A recent series of preclinical studies performed in a canine model have demonstrated that extracted tooth roots (TR) may be successfully used as an alternative autograft for lateral alveolar ridge augmentation and two-stage implant placement [4,5]. TR were separated from either healthy, endodontically treated, or periodontally infected premolars and histologically involved in a replacement resorption, thus resulting in a comparable gain in ridge width as autogenous cortical bone blocks (AB) [4][5][6][7]. These results were recently confirmed in a prospective controlled clinical study, reporting on a mean lateral gain of 10.06 ± 1.85 mm (median: 11.0) in the TR and 9.20 ± 2.09 mm (median: 8.50) in the AB group, respectively. ...
... The power analysis considered a standard normal distribution, a probability of a type I error of .05 and a probability of a type II error of .20. Defining histological gain in ridge height (GRH) as primary outcome variable (sigma: 2.7-3.3 mm) [4,5], a clinically relevant difference was set at 2 mm. A sample size of four animals was calculated to achieve 95% power (Power and Precision, Biostat, Englewood, USA). ...
Objectives
To histomorphometrically evaluate the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical alveolar ridge augmentation.
Materials and methods
Upper premolars were randomly assigned to either autoclavation (TR-A) or an untreated control group (TR-C) and used as block grafts for vertical alveolar ridge augmentation in both lower quadrants (n = 4 beagle dogs). Tissue biopsies were obtained after 15 weeks of submerged healing. Histological analyses considered gain in ridge height (GRH), augmented area (AA), and the proportion of mineralized (MT) and non-mineralized tissue (NMT).
Results
TR-C and TR-A grafts were commonly associated with a complete replacement resorption and a marked gain in ridge height. Significant differences between groups were noted for mean GRH [TR-C: 2.35 ± 0.55 vs. TR-A: 2.46 ± 0.21 mm] and AA [TR-C: 11.88 ± 4.31 vs. TR-A: 8.65 ± 1.59 mm²] values. Within AA, both groups revealed a comparable distribution of mean MT and NMT values. The linear regression analysis pointed to a significant correlation between NMT and AA values.
Conclusions
Both TR-C and TR-A grafts supported vertical alveolar ridge augmentation; however, GRH was improved in the TR-A group.
Clinical relevance
TR grafts may serve as a potential alternative for vertical alveolar ridge augmentation.
... Based on the findings of a recent series of preclinical investigations, autogenous tooth (AT) roots were successfully used for localized lateral alveolar ridge augmentation and a staged implant placement, as well as provided similar treatment outcomes when compared with the respective control sites (i.e., AB) [14][15][16]. Considering these findings, it might be hypothesized that AT can serve as an alternative graft material to AB. ...
... Based on the findings of preclinical animal studies, premature graft exposure following lateral alveolar ridge augmentation using AB and AT blocks was noted in both groups [14][15][16]. This was not associated with any signs of inflammation; however, it resulted in a graft separation from the host bone, thus preventing two-stage implant placement [14,15]. ...
... Based on the findings of preclinical animal studies, premature graft exposure following lateral alveolar ridge augmentation using AB and AT blocks was noted in both groups [14][15][16]. This was not associated with any signs of inflammation; however, it resulted in a graft separation from the host bone, thus preventing two-stage implant placement [14,15]. ...
Aim
The aim of this systematic review was to critically evaluate the currently existing clinical evidence on the efficacy of autogenous teeth (AT) for the reconstruction of alveolar ridge deficiencies.
Materials and methods
A search protocol was developed to answer the focused question: “In patients exhibiting alveolar ridge deficiencies and being in need of an implant retained restoration, what is the efficacy of reconstructive procedures employing AT on changes in ridge dimensions compared with control measures?” Uncontrolled studies were also included to assess the overall efficacy of AT for specific procedures.
Results
A total of six studies (one randomized, one non-randomized controlled, two observational, one controlled case series, one retrospective) were identified. Two studies used AT for staged lateral augmentation, whereas four studies used AT as a demineralized dentin matrix (AutoBT) for the simultaneous grafting of dehiscence-type defects, vertical augmentation of post-extraction sockets, and lateral/transcrestal sinus floor elevation. The reported clinical outcomes following the application of either AT or AutoBT were within the range of those data noted in the respective control groups. Adverse events were commonly not observed.
Conclusions
The available limited studies involved relatively small patient samples and short follow-up periods but pointed to the potential of AT to serve as an alternative material for the reconstruction of alveolar ridge deficiencies.
Clinical relevance
AT appear to be effective in reconstructing alveolar ridge deficiencies.
... Both PM-C and AB-grafted sites equally supported the early stages of osseointegration, as evidenced by histological/immunohistochemical (i.e., boneto-implant contact (BIC), osteocalcin antigen reactivity), biomechanical (i.e., removal torque), and microcomputed tomographic (μCT) (i.e., bone volume per tissue volume for a subset of PM-C specimen) outcomes after 3 weeks of healing [9,10]. Moreover, the clinical and histological outcomes were not impaired by the condition of the roots, since endodontically treated (PM-E) as well as periodontally diseased (PM-P) were equally effective as PM-C grafts [11,12]. ...
... The study was conducted in three experimental phases, which have been reported in detail previously [9,12]. ...
... Tissue biopsies were dehydrated using ascending grades of alcohol and xylene, infiltrated, and embedded in methylmethacrylate (MMA) (Technovit 9100 NEU; Heraeus Kulzer, Wehrheim, Germany) [12,17]. The MMA-embedded samples were scanned with a μCT device (Viva CT 80; Scanco Medical AG, Brüttisellen, Switzerland) operated at 70 kVp, 114 μA, 8 W, 31.9-mm ...
Objectives
Previous research revealed that autogenous tooth roots may be biologically equivalent to conventional bone grafts for lateral ridge augmentation. However, these analyses were limited to two dimensions, whereas healing is a volumetric process. The present study aimed at volumetrically assessing the microstructure following lateral ridge augmentation using extracted tooth roots.
Material and methods
The roots of differently conditioned maxillary premolars (i.e., healthy: PM-C; endodontically treated: PM-E; ligature-induced periodontitis: PM-P) and retromolar cortical autogenous bone (AB) blocks were used for lateral ridge augmentation at chronic-type defects in the lower quadrants of n = 16 foxhounds. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Tissue biopsies were scanned using microcomputed tomography (μCT), and volumes of interest were separated at the buccal and oral aspects to measure bone volume per tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and connectivity density (Conn.D).
Results
All groups investigated revealed comparable BV/TV, Tb.Th, Tb.Sp, and Conn.D values at either the augmented buccal or pristine oral aspects, respectively. A gradual but heterogeneous replacement of grafts was observed in all groups, but residual PM fragments were particularly noted in PM-C and PM-P groups.
Conclusions
Differently conditioned PM and AB grafts were associated with a comparable bone microstructure within the grafted area. The duration of replacement resorption may vary considerably among the subjects.
Clinical relevance
Autogenous tooth roots may serve as potential alternative to AB for localized alveolar ridge augmentation.
... Recent experimental studies have focused on the use of extracted tooth roots (TR) as an alternative scaffold to support bone regeneration at non-self-contained lateral alveolar ridge defects. Various outcome measures based on histological, immunohistochemical, and micro-computed tomographic analyses did not significantly differ between differently conditioned TRs (i.e., healthy, endodontically treated non-infected, periodontally diseased) and retromolar AB grafts [4,6,7]. The median bone-to-implant contact (BIC) values at 3 weeks following implant placement ranged from 36.96 to 50.79% in the TR group and from 32.53 to 64.10% in the AB group [4]. ...
... In particular, after 12 weeks of healing, the histomorphometrical analysis of the augmented area (AA) at the TR-treated sites ranged between 7.55 and 11.20 mm 2 , whereas the median values ranged between 6.60 and 8.56 mm 2 at the AB-treated sites [4]. Similar AA values were also noted when assessing the efficacy of TR grafts that were derived from the periodontally diseased teeth, resulting in 11.01 ± 4.37 mm 2 as compared to 8.07 ± 5.64 mm 2 noted in the AB group [6]. ...
... The regression analysis also revealed that BI26 values were neither related to CWb nor SA26 values. These clinical and radiographic observations are also supported by recent histological analyses pointing to a basal ankylosis and replacement resorption of both TR and AB grafts [4,6,7]. ...
Background:
To assess and compare the radiographic outcomes following lateral alveolar ridge augmentation using autogenous tooth roots (TR) and autogenous bone (AB) blocks.
Methods:
In a total of 30 patients, lateral ridge augmentation was conducted in parallel groups using either (1) healthy autogenous tooth roots (e.g., retained wisdom or impacted teeth) (n = 15) or (2) cortical autogenous bone blocks harvested from the retromolar area. Cone-beam computed tomographic (CBCT) scans taken at 26 weeks of submerged healing were analyzed for the basal graft integration (i.e., contact between the graft and the host bone in %) (BI26) and the cross-sectional grafted area (mm2) (SA26).
Results:
Both groups revealed a comparable clinical width of the alveolar ridge at baseline (CWb). Mean BI26 and SA26 values amounted to 69.26 ± 26.01% (median 72.44) and 22.07 ± 12.98 mm2 (median 18.83) in the TR group and 79.67 ± 15.66% (median 78.85) and 12.42 ± 10.11 mm2 (median 11.36) in the AB group, respectively. Between-group differences in mean SA26 values were statistically significant (p = 0.031). Linear regression analysis failed to reveal any significant correlations between BI26 and CWb/SA26 values in either group.
Conclusions:
TR grafts may be associated with improved SA26 values following lateral alveolar ridge augmentation.
Trial registration:
DRKS00009586 . Registered 10 February 2016.
... The dehiscence rates found in the other tooth augmentation studies of our working group ranged in a comparable area below 7% [1,2,9]. In respective animal studies, dehiscence rates of 20% and 29% [7,8] were described, which were considerably higher than the usually described dehiscence rates in bone grafting in humans and considerably higher than the overall dehiscence rate of around 5% at the patient level in the present study. ...
... Although the endodontic and periodontal infection profiles differ, the same pathogens can generally be found in different frequencies [31]. In the animal studies already mentioned above, relatively high loss rates of augmentations were observed with endodontically treated and periodontally compromised teeth [7,8]. However, no protocol for decontamination of the potentially infected dentin was described in these studies. ...
Tooth shell technique (TST) using autologous dentine is possible with lateral ridge augmentation while avoiding a donor region. This study aimed to clarify whether the use of periodontally compromised teeth (PCT) leads to similar results compared to non-periodontally compromised teeth (NPCT). In this retrospective study, the dentin matrix of 41 patients (PCT: n = 19 with 29 implants; NPCT: n = 22, with 29 implants) was used for TST. All cases were re-examined. Outcome parameters were biological complications, horizontal hard tissue loss, osseointegration, and the integrity of the buccal lamella. Only in one case in the PCT group, a graft was lost. In three cases, minor complications were identified, including two cases of wound dehiscence and one case of inflammation with suppuration (PCT: n = 1, NPCT: n = 3). All implants, except the one with the severe complication, were osseointegrated and the integrity of the buccal bone lamella was preserved. Mean difference of the resorption of the crestal width and the buccal lamella did not differ statistically between the two groups. TST using PCT showed results comparable to those of NPCT in terms of complications and graft resorption. Processed dentin matrix from PCT can be used and applied with predictable results for bone grafting, utilizing TST.
... Transplantation of autogenous dentin grafts became a vital strategy in alveolar bone augmentation [1]. First support for this approach came from preclinical studies [2][3][4] and case reports [4] followed by radiological analysis [5,6]. Preclinical research continues to better understand the process of graft consolidation [7,8] and acellular tooth root may even be used as allografts [9]. ...
... There is a growing evidence in using dentin for extraction socket augmentation and staged implant placement [2][3][4][5][6][7][8]10,11,30]. Graft consolidation is a result of both resorption and formation of the graft [31], thus the release of growth factors from dentin is expected to occur [32]. ...
Dentin prepared from extracted teeth is used as autograft for alveolar bone augmentation. Graft consolidation involves the acid lysis of dentin thereby generating a characteristic paracrine environment. Acid lysate of dentin is mimicking this environment. Acid dentin lysate (ADL) potentially targets hematopoietic cells thereby affecting their differentiation towards macrophages and osteoclasts; however, the question remains if ADL controls macrophage polarization and osteoclastogenesis. Here, we show that ADL reduced lipopolysaccharide (LPS)-induced macrophage polarization of the pro-inflammatory (M1) phenotype, indicated by attenuated Interleukin 1 (IL1), Interleukine 6 (IL6)and cyclooxygenase 2 (COX2) expression. This decrease in M1 macrophages was confirmed by the reduced phosphorylation and nuclear translocation of p65 in the LPS-exposed RAW 264.7 macrophages. Similarly, when RAW 264.7 macrophages were incubated with other agonists of Toll-like receptor (TLR) signaling e.g., FSL1, Polyinosinic-polycytidylic acid High Molecular Weight (Poly (1:C) HMW), Pam3CSK4, and imiquimod, ADL reduced the IL6 expression. We further show herein that ADL decreased osteoclastogenesis indicated by the reduced formation of multinucleated cell expressing cathepsin K and tartrate-resistant acid phosphatase in murine bone marrow cultures. Overall, our results suggest that acid dentin lysate can affect the differentiation of hematopoietic cells to M1 macrophage polarization and a decrease in osteoclastogenesis in bone marrow cultures.
... Animal studies yielded results that indicate that grafts derived from endodontically treated or periodontally compromised teeth did not show increased signs of inflammation histologically. However, increased graft exposures could be observed compared to grafts obtained from uncompromised teeth [14,23]. Teeth that have undergone endodontic treatment, for example, may host residual bacteria in the dentin that were not eliminated by the endodontic procedure. ...
... Based on CBCT data, it is not possible to determine whether the dentin shell and particulate has been remodeled by osseous replacement or if unaltered dentin is present, especially since the dentin shell remains clearly delineable. However, there is histological evidence that dentin undergoes gradual replacement resorption and promotes new bone formation [14,16,23,36,37]. ...
Autogenous dentin has been reported to be a suitable grafting material for certain indications. The purpose of this study was to assess the feasibility of using endodontically treated teeth for this application. In the present retrospective study, one-stage augmentation of lateral ridge defects with a dentin shell and particulate (tooth shell technique (TST)) either obtained from endodontically treated teeth (ETT, 17 patients with 21 implants) or non-endodontically treated teeth (NETT, 17 patients with 24 implants) were analyzed. Follow-up was conducted 3 months after augmentation. The target parameters were biological complications, horizontal hard tissue loss, osseointegration, and the integrity of the buccal lamella. Only minor complications occurred in three implants from three patients, including two cases of wound dehiscence (one each in ETT and NETT) and a localized three-walled defect in the NETT group, which was solved by re-augmentation. All the implants were osseointegrated and the integrity of the buccal lamella was preserved. The mean difference of the resorption of the crestal width and the buccal lamella did not differ statistically between the two groups. As TST using ETT showed, the results comparable to those of NETT dentin from endodontically treated teeth can be safely applied with predictable results for this grafting technique.
... Moreover, there is evidence that avulsed teeth reimplanted back in the socket recombine to the bone. Schwarz et al. have observed that the new bone structure rises on dentine or cementum, causing ankyloses [43]. This ankylosis root is constantly resorbed and replaced by bone while the alveolar bone is retained. ...
The specific combinations of materials and dopants presented in this work have not been previously described. The main goal of the presented work was to prepare and compare the different properties of newly developed composite materials manufactured by sintering. The synthetic- (SHAP) or natural- (NHAP) hydroxyapatite serves as a matrix and was doped with: (i) organic: multiwalled carbon nanotubes (MWCNT), fullerenes C60, (ii) inorganic: Cu nanowires. Research undertaken was aimed at seeking novel candidates for bone replacement biomaterials based on hydroxyapatite—the main inorganic component of bone, because bone reconstructive surgery is currently mostly carried out with the use of autografts; titanium or other non-hydroxyapatite -based materials. The physicomechanical properties of the developed biomaterials were tested by Scanning Electron Microscopy (SEM), Dielectric Spectroscopy (BSD), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry (DSC), as well as microhardness using Vickers method. The results showed that despite obtaining porous sinters. The highest microhardness was achieved for composite materials based on NHAP. Based on NMR spectroscopy, residue organic substances could be observed in NHAP composites, probably due to the organic structures that make up the tooth. Microbiology investigations showed that the selected samples exhibit bacteriostatic properties against Gram-positive reference bacterial strain S. epidermidis (ATCC 12228); however, the property was much less pronounced against Gram-negative reference strain E. coli (ATCC 25922). Both NHAP and SHAP, as well as their doped derivates, displayed in good general compatibility, with the exception of Cu-nanowire doped derivates.
... It was shown that calcium and phosphates are still present within the collagen components even after the particle cleaning procedures that are conducted before use [38]. It was reported in several studies that the dentin graft was replaced more homogeneously by newly formed bone than in the autogenous bone grafts, concluding that the roots of extracted teeth revealed a structural and biological potential to work as an autograft alternative to autogenous bone [39,40], and even supported the early stages of osseointegration after implant placement very similar to autologous bone [41]. As pointed out in a recent systematic review, studies evaluating autologous teeth as grafting material involved only small patient numbers and short follow-up periods. ...
Background:
The maintenance of ridge volume following tooth extraction has gained more importance in the last few years. This clinical study aimed to assess the impact of autologous dentin particles mixed with injectable platelet-rich fibrin (i-PRF) on a sticky tooth mixture for socket preservation in terms of consecutive need for horizontal guided bone regeneration and histological findings.
Methods:
Eight extraction sockets in seven patients were included in this study. Autologous dentin particles were mixed with PRF, filled in the sockets, and covered with a cross-linked collagen membrane exposed to the oral cavity and fixated by crisscross sutures. An orthopantomogram was taken before the first surgical procedure and a CBCT prior to static computer-aided implant surgery. At the time of implant placement, cores were harvested with the aid of a trephine for histological examinations for every preserved socket.
Results:
No further horizontal GBR intervention was required in any cases, and the histological findings were unremarkable. The new bone was mostly cancellous and in direct contact with the remaining dentin granules.
Conclusions:
Within the limits of this clinical study, it may be concluded that this method is valuable for socket preservation and obtaining vital and good quality bone structure. The sticky tooth technique seems to be very efficient despite the more complex equipment.
... The production of demineralized dentin is time-consuming, cost-intensive and complicated, which restricts its widespread use in clinics. Periodontally infected tooth root can also serve as an alternative after thorough debridement, plane, removal of cementum in contact with host bone [35,36]. For nonretainable contaminated teeth, autoclavation (15 mins, 134 °C) is used for decontamination. ...
Objectives
To investigate the outcome and short-term follow-up of autogenous tooth shell (TS) grafting for bone augmentation in the esthetic zone, as well as stability and esthetics of implant-supported restoration.
Materials and methods
A total of 8 patients with 11 implants in 11 sites were enrolled in this study. All the horizontal and/or vertical bone defects in the esthetic zone were augmented by tooth shells, which were fixed laterally to the residual bone with osteosynthesis screws. The gap between the shell and residual bone was filled with Bio-Oss® granules. Four months after bone augmentation, dimensionally sufficient dental implants were inserted and implants-supported prostheses were made 3 months later. The esthetic outcome was evaluated by pink esthetic score (PES) and white esthetic score (WES) one year after prosthetic restoration. Horizontal ridge width (HRW) was assessed before and immediately after bone augmentation, as well as 4 and 19 months post-augmentation by radiography. The stability and absorption of TS grafts were evaluated at the 4th and 19th months post-augmentation.
Results
Though wound dehiscences occurred in 3 cases, secondary healings were obtained after TS modification and irrigation. The other 5 cases went through uneventful healing during the whole observation period. Radiographic examination showed that HRW was 8.01 ± 0.93 mm (median: 7.80, 95% CI 7.38, 8.64) 4 months after TS augmentation, which was statistically different compared to HRW (2.72 ± 1.73 mm) at the baseline. Mean HRW gain was 5.29 ± 2.03 mm (median: 4.60, 95% CI 3.92, 6.66). Three-dimensional bone volume in all the augmented sites was sufficient for dental implants insertion and prosthetic restoration. Follow-up of one year showed stable marginal bone around dental implants. The implant survival rate was 100%. HRW losses were 0.65 ± 0.43 mm (the 4th month) and 1.05 ± 0.54 mm (the 19th month) compared to HRW immediately after augmentation. The PES and WES of final prosthetic restorations were 8.09 ± 0.70 and 8.91 ± 0.54, respectively.
Conclusions
Autogenous tooth shell grafting is a reliable approach for bone augmentation in the esthetic zone for dental implant treatment, allowing for favorable stability and esthetic outcome of implant-supported prosthesis within the one-year follow-up period.
... The latter findings are at least in part supported by previous experimental studies, also indicating that tooth roots that were used for lateral ridge augmentation, were gradually involved in the bone remodeling process and associated with a replacement resorption. 28,29 When evaluating the results noted in the CO group, it must however be emphasized that these teeth revealed neither an endodontic nor a periodontal infection, which in turn may not reflect the known influence of oral infections on the onset and progression of MRONJ. 30,31 Another potential limitation of the present analysis is related to the lack of immunohistochemical analyses or specific staining techniques (eg, staining of tartrate-resistant acid phosphatase in osteoclasts) to further assess bone remodeling processes in different groups. ...
Background
To assess the influence of ridge preservation procedures on the healing of extraction sockets under antiresorptive therapy.
Material and Methods
A total of 10 Dutch Belted rabbits were randomly allocated to either the intravenous administration of amino‐bisphosphonate (zoledronic acid) (Za) (n = 5) or a negative control group (no Za [nZa]) (n = 5). At 6 months, the mandibular and maxillary molars were extracted and the four experimental sites randomly allocated to the following subgroups: (a) socket grafting using a collagen‐coated natural bone mineral (BOC) + primary wound closure, (b) coronectomy (CO), or (c) spontaneous healing + primary wound closure (SP). Za medication was continued for another 4 months. Histomorphometrical analyses considered, for example, crestal hard tissue closure of the extraction site (C) and mineralized tissue (MT) formation.
Results
Za‐SP was associated with an incomplete median C (31.76% vs 100% in nZa‐SP) and signs of bone arrosion along the confines of the socket. BOC had no major effects on increases in C and MT values in the Za group. CO commonly resulted in an encapsulation and partial replacement resorption of residual roots by MT without any histological signs of osteonecrosis.
Conclusions
(a) Za‐SP was commonly associated with a compromised socket healing and signs of osteonecrosis, (b) BOC had no major effect on socket healing in the Za group, and (c) CO at noninfected teeth might be a feasible measure for the prevention of a Za‐related osteonecrosis of the jaw.
... Результаты гистологического анализа не показали значимых расхождений результатов среди трех групп. Согласно выводам авторов, зубы с заболеваниями пародонта могут быть использованы как альтернативный источник аутогенного материала [10]. ...
... In contrast, to reduce a peripheral graft resorption, the cementum was preserved at the upward and lateral aspects of the roots. 27,28 In another study, Dentin blocks from human premolars extracted for orthodontic reasons were prepared by removing the crown, cutting the root into two halves and removing the pulp and periodontal ligament mechanically. Blocks sized 5-6 mm in diameter with a thickness of 3 mm were prepared and cleaned by being placed in 1% chlorhexidine for 10 min. ...
... In contrast, to reduce a peripheral graft resorption, the cementum was preserved at the upward and lateral aspects of the roots. 27,28 In another study, Dentin blocks from human premolars extracted for orthodontic reasons were prepared by removing the crown, cutting the root into two halves and removing the pulp and periodontal ligament mechanically. Blocks sized 5-6 mm in diameter with a thickness of 3 mm were prepared and cleaned by being placed in 1% chlorhexidine for 10 min. ...
Abstract
Aim: Regeneration of bone defects is a major problem that continues to inspire the design of new bone materials.
Autogenous bone, with its osteogenic, osteoinductive and osteoconductive properties, has long been considered the
ideal grafting material in bone reconstructive surgery although due to its limitations, various bone substitutes has been
introduced. The aim of this literature review was to evaluate autogenous dentin as a bone substitute.
Method: Electronic Search was conducted in a direct scientific article, Google Scholar, update, Wiley online library,
PubMed with keywords for autogenous dentin, bone grafts, growth factors, Autogenous tooth, Allografts, Alloplastic
bone, Xenografts between 2010 and 2017, and selected articles that are more relevant to the subject.
Result: Healing of autogenous bone grafts entails both osteoconduction, where new bone is gradually formed around
the resorbing graft, and osteoinduction, where released proteins are capable of stimulating osteoblasts or pre-osteoblasts
to form new bone. Allografts have been found to possess bone-stimulating proteins and, consequently, osteoinductive
properties.
Conclusion: Autogenous dentin can be used as an appropriate bone substitute. The present results indicate that the
treated autogenous dentin graft could be used as a bone substitute for enhancing bone regeneration.
Key words: Autogenous Dentin, Bone Substitute, Bone Grafts.
... In contrast, to reduce a peripheral graft resorption, the cementum was preserved at the upward and lateral aspects of the roots. 27,28 In another study, Dentin blocks from human premolars extracted for orthodontic reasons were prepared by removing the crown, cutting the root into two halves and removing the pulp and periodontal ligament mechanically. Blocks sized 5-6 mm in diameter with a thickness of 3 mm were prepared and cleaned by being placed in 1% chlorhexidine for 10 min. ...
Aim: Regeneration of bone defects is a major problem that continues to inspire the design of new bone materials. Autogenous bone, with its osteogenic, osteoinductive and osteoconductive properties, has long been considered the ideal grafting material in bone reconstructive surgery although due to its limitations, various bone substitutes has been
introduced. The aim of this literature review was to evaluate autogenous dentin as a bone substitute.
Method: Electronic Search was conducted in a direct scientific article, Google Scholar, update, Wiley online library, PubMed with keywords for autogenous dentin, bone grafts, growth factors, Autogenous tooth, Allografts, Alloplastic bone, Xenografts between 2010 and 2017, and selected articles that are more relevant to the subject.
Result: Healing of autogenous bone grafts entails both osteoconduction, where new bone is gradually formed around the resorbing graft, and osteoinduction, where released proteins are capable of stimulating osteoblasts or pre-osteoblasts to form new bone. Allografts have been found to possess bone-stimulating proteins and, consequently, osteoinductive
properties.
Conclusion: Autogenous dentin can be used as an appropriate bone substitute. The present results indicate that the treated autogenous dentin graft could be used as a bone substitute for enhancing bone regeneration.
... Recent studies have focused on dentin as a potential bone substitute in different models of alveolar defects. It could be shown that dentin, being used either as a block graft or in particulated form, is involved in bone remodelling, expressing osteoconductive and even osteoinductive properties [3,5,9,26,29,30]. In vivo studies in mice showed that dentin scaffolds performed similar with regard to the inflammatory response and neovascularization compared to isogenic bone [9]. ...
IntroductionRidge preservation can be performed with autologous bone, alloplastic bone substitute material or a combination of both. Dentin is similar to bone in its chemical composition. In its use as bone substitute material, it undergoes a remodelling process and transforms to bone. The presented case report introduces a technique in which the extraction socket is augmented with autologous, particulated dentin. Material and methodsThe fractured, non-savable mesial incisor of the upper jaw was carefully extracted in axial direction. After the extraction, the tooth was cleared from remaining periodontal tissue. The vital pulp tissue or a root canal filling, enamel and cementum were also removed. Following the particulation of the remaining dentin in a bone mill, the dentin particles were immediately filled orthotope into the alveolar socket. The soft tissue closure was performed with a free gingival graft of the palate. ResultsAfter an observation period of 4 months, an implant was placed in the augmented area, which osseointegrated successfully and could be restored prosthodontically in the following. The results of this method showed a functional and aesthetic success. Conclusion
The pre-implantological, autologous ridge preservation with dentin could be performed successfully. For the establishment of dentin as augmentation material for jaw augmentation procedures, a prospective, clinical trial is now necessary.
Autologous tooth-derived grafts (ATDGs) have gained popularity as bone substitute biomaterials, owing to their promising healing dynamics in vivo and to patient preference for repurposing hopeless teeth. Nonetheless, concerns exist regarding the biologic response of these ATDGs in preparation for implant placement and subsequent osseointegration. After 12 weeks of extraction socket healing, an implant with an acid-etched surface was placed using osseodensification osteotomy preparation and was retrieved after 16 weeks of integration. Histologic analysis revealed ≥ 64% of direct bone-to-implant contact at multiple regions of interest along the implant surface. Residual dentin particles were scarce and were never found in contact with the implant, suggesting that the ATDG did not interfere with implant osseointegration. Despite the overall trabecular structure of the adjacent maxillary bone with large marrow spaces, the implant surface was delineated with a continuous dense mineralized zone (thickness of 2 to 5 cell layers) with vital osteoblasts in the lacunae. These results suggest that the healing dynamics of ATDG are well aligned with implant osseointegration dynamics.
Objectives:
To assess and compare the efficacy and safety of autogenous tooth roots (TRs) and autogenous bone blocks (ABs) for combined vertical and horizontal alveolar ridge augmentation and two-stage implant placement.
Materials and methods:
A total of 28 patients in need of implant therapy and vertical ridge augmentation were allocated to parallel groups receiving either healthy autogenous tooth roots (e.g., retained wisdom teeth) (n = 14, n = 15 defects) or cortical autogenous bone blocks harvested from the retromolar area (n = 14, n = 17 defects). After 26 weeks of submerged healing, the clinical reduction in ridge height (RH) deficiency was defined as the primary outcome.
Results:
Both surgical procedures were associated with a similar mean reduction in RH deficiency values, amounting to 4.48 ± 2.42 mm (median: 4.25; 95% CI: 3.08-5.88) in the TR group and 4.46 ± 3.31 mm (median: 3.00; 95% CI: 2.54-6.38) in the AB group (p = .60, Mann-Whitney U-test). In all patients investigated, the reduction in RH deficiency values allowed for an adequate implant placement at the respective sites. The frequency of complications (e.g., soft tissue dehiscences) was low (TR: n = 4; AB: n = 0).
Conclusions:
Up to staged-implant placement, both TR and AB grafts appeared to be associated with comparable efficacy and safety for combined vertical and horizontal alveolar ridge augmentation.
This systematic literature review set out to investigate the clinical outcomes of autogenous tooth root blocks used for ridge augmentation: survival rates, block resorption, implant survival, post-surgical complications, and histology findings. This review followed PRISMA guidelines. An automated search was made in four databases, supplemented by a manual search for relevant articles published before December 2020. The quality of evidence provided was assessed with the Newcastle–Ottawa Quality Assessment Scale and the Joanna Briggs Institute Critical Appraisal tool. Seven articles fulfilled the inclusion criteria and underwent analysis. The articles included a total of 136 patients, who received 118 autogenous tooth root blocks and 26 autogenous bone blocks showing block survival rates of 99.15% and 100%, respectively. Tooth root blocks presented a mean bone gain that was similar to autologous bone blocks but showed less resorption. The implant survival rate was 98.32% for autogenous tooth root blocks. Reconstruction of alveolar crests by means of autogenous tooth root blocks appears to be a satisfactory option for single-tooth gaps and low grades of bone atrophy in terms of the survival of the bone block and the implants placed subsequently. More research providing long-term data is needed to confirm these findings.
Particulate autologous tooth roots are increasingly used for alveolar bone augmentation; however, the proteomic profile of acid dentin lysate and the respective cellular response have not been investigated. Here we show that TGF-β1 is among the 226 proteins of acid dentin lysate (ADL) prepared from porcine teeth. RNA sequencing identified 231 strongly regulated genes when gingival fibroblasts were exposed to ADL. Out of these genes, about one third required activation of the TGF-β receptor type I kinase including interleukin 11 (IL11) and NADPH oxidase 4 (NOX4). Reverse transcription-quantitative polymerase chain reaction and immunoassay confirmed the TGF-β-dependent expression of IL11 and NOX4. The activation of canonical TGF-β signaling by ADL was further confirmed by the phosphorylation of Smad3 and translocation of Smad2/3, using Western blot and immunofluorescence staining, respectively. Finally, we showed that TGF-β activity released from dentin by acid lysis adsorbs to titanium and collagen membranes. These findings suggest that dentin particles are a rich source of TGF-β causing a major response of gingival fibroblasts.
Objectives
To assess the short‐term clinical outcomes of lateral augmentation of deficient extraction sockets and two‐stage implant placement using autogenous tooth roots (TR).
Material & Methods
A total of n=13 patients (13 implants) were available for the analysis.
At the time of tooth extraction, each subject had received lateral augmentation using the respective non‐retainable but non‐infected tooth root where the thickness of the buccal bone was <0.5 mm or where a buccal dehiscence‐type defect was present. Titanium implants were placed after a submerged healing period of 6 months and loaded after 20±2 weeks (V8). Clinical parameters (e.g. bleeding on probing ‐ BOP, probing pocket depth – PD, mucosal recession – MR, clinical attachment level – CAL) were recorded at V8 and after 26±4 weeks (V9) of implant loading.
Results
At V9, all patients investigated revealed non‐significant changes in mean BOP (‐19.23±35.32%), PD (0.24±0.49 mm), MR (0.0±0.0 mm) and CAL (0.24±0.49 mm) values, respectively. There was no significant correlation between the initial gain in ridge width and changes in BOP and PD values.
Conclusions
The surgical procedure was associated with stable peri‐implant tissues on the short‐term.
This chapter aims to evaluate the influence of the grafted biomaterials on the cellular wound healing environment during the inflammatory and repair phases which culminate during the initial few weeks and the remodeling of the newly formed bone and the residual grafted biomaterial which may spread through several years. Three progressive phases of healing ensue after grafting surgery of an extraction site and bone defects, namely inflammatory phase, regenerative phase, and subsequent remodeling. The remodeling of the residual host alveolar bone, the regenerated engineered new tissues, and the grafted biomaterial are largely governed by changes in functional strains at the grafted site. In summary, the use of scaffolds for preserving or reconstructing the alveolar bone ridge became a frequent surgical procedure. It signifies the interaction between the scaffold biomaterial and the host innate immune response. The optimal scaffolding occurs, when the scaffold resorption is at the same pace as the newly deposited replacing bone.
Purpose:
The purpose of this study was to analyze the projects submitted to the ITI International Team for Implantology for funding and the scientific publications ensuing from these projects, over a period of 30 years.
Materials and methods:
This analysis was performed based on information available in the database of the ITI. For each project, data related to institution, country of origin, and grant status (financed or rejected) were extracted. For the financed projects, the grant amount and number of publications were recorded. Publications were searched independently by two investigators. For all publications, the study topic, study design, and citation number were recorded.
Results:
From a total of 1,372 submitted projects from 51 different countries and 308 different institutions, 514 (37.46%) were financed by the ITI. This amounts to more than CHF 52 million invested in favor of implant dentistry and related fields. A total of 552 publications (including original research and reviews) were identified related to these projects, with the majority being in vitro studies (n = 198), and the most common topic researched was implant surface modification (n = 134). The United States was the country and the University of Bern was the institution with the largest number of financed projects and published papers.
Conclusion:
This analysis revealed that the ITI has been actively supporting research in the field of implant dentistry and related areas globally. Several concepts in present-day implantology are based on literature from ITI-funded projects.
Objectives:
To assess the short-term clinical outcomes of lateral alveolar ridge augmentation using autogenous tooth roots (TR) and autogenous bone blocks (AB).
Material & methods:
A total of n=23 patients (23 implants) were available for the analysis. Each subject was allocated to lateral ridge augmentation using either 1) healthy autogenous tooth roots (e.g. retained wisdom or impacted teeth) (n=13), or 2) cortical autogenous bone blocks harvested from the retromolar area (n=10). Clinical parameters (e.g. bleeding on probing - BOP, probing pocket depth - PD, mucosal recession - MR, clinical attachment level - CAL) were recorded at (V8) and after 26±4 weeks (V9) of implant loading.
Results:
TR and AB groups were associated with comparable (p>0.05) changes in mean BOP (-23.0±34.3%; -11.75±24.9%), PD (-0.03±0.14 mm; -0.1±0.29 mm), MR (0.0±0.0 mm; 0.0±0.0 mm) and CAL (-0.03±0.14 mm; -0.1±0.29 mm) values. The regression analysis failed to reveal any significant correlations between changes in BOP and PD values and the initial as well as the ridge width measured at 26 weeks.
Conclusions:
TR and AB were associated with comparable clinical short-term outcomes. This article is protected by copyright. All rights reserved.
Objectives
To assess the feasibility of using autogenous tooth roots (TR) for a lateral augmentation of deficient extraction sockets and two‐stage implant placement.
Material and Methods
A total of 15 patients were recruited to perform a simultaneous, lateral augmentation of deficient (i.e., thickness of the buccal bone < 0.5 mm or buccal dehiscence‐type defects) fresh extraction sockets using the respective non‐retainable but non‐infected teeth (n = 15). After 26 weeks of submerged healing, the primary endpoint was defined as the crestal ridge width (mm) (CW26) being sufficient to place an adequately dimensioned titanium implant at the respective sites.
Results
The surgical procedure could be accomplished in n = 14 patients. Soft tissue healing was uneventful in all patients. CW26 at visit 6 allowed for a successful implant placement in all patients (e.g., 14/14). Mean CW26 values amounted to 10.85 ± 2.71 mm (median: 8.5). The change (4.89 ± 2.29 mm) in CW compared to baseline was statistically significant (p < 0.001).
Conclusions
The usage of TR may represent a feasible approach for lateral augmentation of deficient extraction sockets and two‐stage implant placement.
Objectives
To assess the influence of autoclavation on the efficacy of extracted tooth roots (TR) used for vertical alveolar ridge augmentation and two‐stage osseointegration.
Material & Methods
Maxillary premolars were randomly assigned to either autoclavation (TR‐A) or were left untreated (TR‐C) and used as block grafts for vertical alveolar ridge augmentation in both lower quadrants (n=4 beagle dogs). At 12 weeks, titanium implants were inserted and left to heal for 3 weeks. Histological analyses considered vertical bone gain (BD‐BC); augmented area (AA) and bone‐to‐implant contact (BIC) at vestibular (v) and oral (o) aspects.
Results
Both TR‐C and TR‐A (exposures n=3) grafts were associated with a replacement resorption and marked vertical bone gain. Median BD‐BC [TR‐C: 1.45 (v) to 1.62 mm (o) vs. TR‐A: 0.97 (v) to 1.79 mm (o)] and AA [TR‐C: 0.64 (v) to 2.36 mm² (o) vs. TR‐A: 0.22 (v) to 2.36 mm² (o) ] values were comparable in both groups. V BIC [TR‐C: 49.32 (v) to 52.97% (o) vs. TR‐A: 25.34 (v) to 46.11% (o)] values were significantly higher in the TR‐C group.
Conclusions
Both TR‐C and TR‐A grafts equally supported vertical alveolar ridge augmentation, however, osseointegration was partially facilitated in the TR‐C group.
This article is protected by copyright. All rights reserved.
Background
The objectives of the present pilot study are to compare via CBCT the alveolar contraction suffered both vertically and horizontally between the control group and the group using autologous dental material (ADM), as well as to study the densitometric differences between both post-extraction sockets.
Material and Methods
A split-mouth study was performed in n = 9 patients who required two extraction of single-rooted teeth deemed suitable for deferred rehabilitation with osseointegrated implants. Two groups were formed — a control group, in which the post-extraction socket was not filled, and an ADM group, in which the alveolar defect was filled with freshly processed autogenous dental material. Both dimensional and densitometric analyses of the alveoli were performed in both groups immediately after surgery (baseline), as well as 8 weeks and 16 weeks later.
Results
The mean height of alveolar bone loss was: VL (Control 1.77 mm, loss of 16.87% of initial alveolar height; ADM 0.42 mm, loss of 4.2% of initial alveolar height), HL-BCB (Control 2.22 mm, ADM 0.16 mm, p= 0.067 at 16 weeks). The mean bone loss of the vestibular width (VL-BCB) was much higher in the control group (1.91 mm at 1 mm, 1.3 mm at 3 mm, and 0.89 mm at 5 mm) than in the ADM group (0.46 mm at 1 mm, 0.21 mm at 3 mm, 0.01 at 5 mm, p=0.098 at 16 weeks). At 16 weeks, densitometric analysis of the coronal alveolar area revealed a bone density of 564.35 ± 288.73 HU in the control group and 922.68 ± 250.82 HU in the ADM group (p=0.045 ).
Conclusions
In light of these preliminary results, autologous dentine may be considered a promising material for use in socket preservation techniques.
Key words:Ridge preservation, dimensional height and width changes, post-extraction socket, tooth extraction, autogenous particulate dentine graft.
Introduction
The objective of this study was to clinically evaluate an autogenous tooth graft (ATG) as a novel bone graft material in the treatment of grade II furcation defects. ATG is prepared at chairside from a freshly extracted tooth to be used immediately for bone regeneration. It has an advantage over the autogenous and other bone graft materials as it is non‐immunogenic, inexpensive, easily available, and lacks donor‐site morbidity.
Case Series
This study was conducted on three middle‐aged (35–55 years) male patients, which had at least one mandibular molar with grade II furcation involvement (a total of 5 sites) and one tooth that required extraction because of poor prognosis and was not endodontically treated. At 9 and 12 months, the mean reductions in horizontal probing depth were (1.40±0.57 mm) and (1.52±0.59 mm), respectively, and the mean gains in linear bone‐fill were (3.90±0.15 mm) and (5.33±0.10 mm), respectively.
Conclusion
Within the limitation of this study, ATG exhibited ideal properties for alveolar bone regeneration. In addition, this study outlines the chairside method to prepare a graft and highlights the improvement in clinical and radiographic parameters at 9 and 12 months.
This article is protected by copyright. All rights reserved
Objectives
To assess and compare the efficacy and safety of autogenous tooth roots (TR) and autogenous bone blocks (AB) for lateral alveolar ridge augmentation and two‐stage implant placement.
Material & Methods
A total of 30 patients in need of implant therapy and lateral ridge augmentation were allocated to parallel groups receiving either 1) healthy autogenous tooth roots (e.g. retained wisdom or impacted teeth) (n=15), or 2) cortical autogenous bone blocks harvested from the retromolar area. After 26 weeks of submerged healing, the primary endpoint was defined as the crestal ridge width (mm) (CW26) being sufficient to place an adequately dimensioned titanium implant at the respective sites.
Results
Soft tissue healing was uneventful in both groups. CW26 at visit 6 allowed for a successful implant placement in all patients of both TR (15/15) and AB groups (15/15). Mean CW26 values amounted to 10.06±1.85 mm (median: 11.0) in the TR and 9.20±2.09 mm (median: 8.50) in the AB group, respectively. The difference between both groups did not reach statistical significance (P=0.241).
Conclusions
TR may serve as an alternative graft to support lateral alveolar ridge augmentation and two‐stage implant placement.
This article is protected by copyright. All rights reserved.
Purpose:
The objective of this systematic review was to assess the clinical efficacy of the tooth-bone graft as a bone substitute in the oral and maxillofacial region in humans as compared to ungrafted sites and other bone substitutes.
Materials and methods:
Databases were electronically and manually searched up to January 2017 to identify animal and human studies and a risk of bias analysis and descriptive statistics was performed.
Results:
Eighteen animal controlled trials (401 animals), 4 human randomized controlled trials, 1 cohort study, and 3 controlled trials (184 patients) were included. Graft processing was highly heterogeneous. 71.42% clinical and 55.56% animal studies reported no significant difference between tooth-bone graft and controls. Histologically, a dentin-bone complex was reported. A low risk of bias was noted in only 50% of the randomized controlled trials and 63.33% animal study entries. An independent analysis of 6 high-quality case reports (350 patients) revealed complications in 18.86% cases.
Conclusion:
Tooth-bone graft demonstrated no added benefits over conventional graft materials. Absence of standardized processing and heterogeneous study results limit its use in clinical practice. Until long-term studies determine its success, clinicians are recommended to use it with caution because of high variability in resorption time (2-24 weeks) and a risk of graft dehiscence (12.96%-34.38%).
Purpose:
The present study was undertaken to evaluate the healing pattern of xenogenic demineralized dentin onlay grafts in comparison with autogenous bone grafts to the rabbit tibia.
Material and methods:
Eight 6-month-old New Zealand male rabbits were used in the experiments. Standardized sized dentin blocks from human premolars and similar autogenous bone blocks harvested from tibia were grafted as onlay blocks on each tibia (n = 8 × 2). All animals were killed after a healing period of 12 weeks.
Results:
Healing was uneventful for all animals. In general, both the dentin and bone block grafts were fused to the bone, resorbed, and replaced by bone and connective tissue to a varying degree. Both types of grafts were still present after 12 weeks, on an average to approximately one third of the original sizes. Resorption cavities could be seen in the dentin with bone formation. Zones of osseous replacement resorption of the dentin could be noted. In both graft types, higher rate of bone formation was seen at the interface between graft and recipient site.
Conclusion:
Demineralized xenogenic dentin onlay grafts showed similar resorption characteristics as autogenous bone onlay grafts, being resorbed in a similar rate during 12 weeks. New bone formation occurred mainly in terms of replacement resorption in the interface between dentin/bone graft and native bone.
Objectives:
To assess the clinical safety and performance of collagenated xenogeneic bone block (CXBB) for lateral alveolar ridge augmentation and two-stage implant placement.
Material & methods:
In ten patients exhibiting a single-tooth gap, the surgical procedure included the preparation of mucoperiosteal flaps, a rigid fixation of CXBB (Geistlich Bio-Graft® ) using an osteosynthesis screw, and contour augmentation. After 24 weeks of submerged healing, the primary endpoint was defined as the final ridge width sufficient to place an adequately dimensioned titanium implant at the respective sites. Secondary outcomes included, for example, the gain in ridge width (mm). Clinical parameters (e.g., bleeding on probing - BOP, probing depth - PD, mucosal recession - MR) were assessed immediately after the cementation of the crown and at the final visit.
Results:
At 24 weeks, implant placement could be achieved in 8 of 10 patients exhibiting a mean gain in ridge width (mean ± SD) of 3.88 ± 1.75 mm. Histological analysis has pointed to a homogeneous osseous organization of CXBB. The changes of mean BOP, PD, and MR values at the final visit amounted to 16.62 ± 32.02%, 0.04 ± 0.21 mm, and -0.04 ± 0.12 mm, respectively.
Conclusions:
CXBB may be successfully used to support lateral alveolar ridge augmentation and two-stage implant placement.
Objectives:
Recent animal studies have indicated, that tooth roots reveal a structural and biological potential to serve as alternative autografts for localized ridge augmentation. This proof-of-concept initial report aimed at investigating, whether this new surgical concept may be applied to humans.
Material & methods:
In one patient, who was in need for horizontal ridge augmentation, the roots of a retained upper wisdom tooth were separated and rigidly fixed at the defect site. After 24 weeks of submerged healing, the primary endpoint was defined as gain in ridge width (mm) being sufficient to place an adequately dimensioned titanium implant at the respective site. Secondary outcomes included safety assessments.
Results:
Soft tissue healing was uneventful during the entire observation period. Clinical re-entry at 24 weeks revealed, that the transplanted root was homogeneously incorporated at the former defect site and mainly replaced by a newly formed hard tissue. The gain in ridge width amounted to 4.5 mm and allowed for a successful implant placement with good primary stability. The procedure was not associated with any wound infection or adverse events.
Conclusions:
This novel approach may be further investigated in implant site development procedures. This article is protected by copyright. All rights reserved.
Bone grafting uses a wide range of materials derived mainly from exogenous sources. Autogenous teeth are often used fresh or fixed with alcohol for later use. Proposed here is a method of using cryogenically preserved autogenous extracted teeth, which could be macerated after thawing. This method avoids the possibility of tissue being denatured by alcohol and preserves intact all calcified structures for optimal bone grafting success.
Objectives:
To assess biomechanical, micro-computed tomographic (micro CT) and immunohistochemical characteristics of early osseous integration at titanium implants placed following lateral ridge augmentation using autogenous extracted tooth roots.
Material & methods:
The roots of healthy maxillary premolars (PM) and retromolar cortical autogenous bone (AB) blocks were used for lateral ridge augmentation at chronic-type defects in the lower quadrants of n = 16 foxhounds. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Osteocalcin (OC) antigen reactivity, removal torque values (RT) and the bone volume per tissue volume (micro CT- BV/TV) along the implants were assessed.
Results:
Median OC (PM: 6.71 vs. AB: 2.73%), RT (PM: 61.97 vs. AB: 44.8 Ncm) and BV/TV (PM: 0.34 vs. AB: 0.21) values were comparable in both PM and AB groups.
Conclusions:
PM and AB grafted sites equally supported the early stages of osseointegration.
Objective
This study describes a new approach to regenerate bone defect using autogenous tooth. Materials and methodsFreshly extrac-ted teeth were used as autogenous grafts. Teeth were sectioned, cut into desired shape, and disinfected. The grafts were rigidly fixed to the mandibular defects in eighteen rabbits using titanium screws to achieve good stability. Every six rabbits were stochastically sacrificed at 1, 3, and 6 months after implantation, respectively. For all specimens, clinical, radiographical, and histological measurements were performed. ResultsThe boundaries of the grafts were distinctly visible in the implanted area during the first and third month. However, the teeth grafts were fully covered by new bone by the sixth month. The radiograph demonstrated the progressive change in the bone and grafted tooth interface from radiolucency to radiopacity during different time periods. Histologically, vascularization led to a temporary fibrous integration in the graft-bone interface. The bone contact rate of 1 and 3 months was significantly lower than that of the 6 months. During this period, grafts were gradually resorbed and replaced by new bone. Conclusion
Rigid fixation of autogenous tooth could serve as a novel approach for the repair of bone defect.
Because vertical ridge augmentation with autogenous bone blocks carries with it a risk of graft resorption and donor site morbidity, the aim of the present study was to compare histologically the healing following vertical ridge augmentation using screwable, xenogenous deproteinized blocks or autologous bone blocks in dogs.
Standardized vertical mandibular defects were surgically created in edentulous ridges of six foxhounds. Two bone blocks (6 x 10 x 15 mm) were inserted on each mandibular side and fixed with both a titanium implant and an osteosynthetic screw. Three different therapies were tested: (1) xenogenous block alone; (2) xenogenous block, covered with a chemically cross-linked collagen membrane; and (3) autologous blocks, harvested during defect preparation. After 3 months of submerged healing, the miniscrews were removed and replaced by dental implants. Following an additional healing period of 3 months, the animals were sacrificed, and dissected blocks were prepared for histomorphometric analysis.
During the primary healing period, three of 12 hemimandibles (six blocks) had to be removed because of severe inflammatory reactions (two xenogenous block sites with collagen membrane, one autologous block site). In general, histologic analysis revealed that xenogenous blocks, used alone or combined with a collagen membrane, exhibited osteoconductive properties on a level equivalent to that of autologous blocks, resulting in means of 50% to 60% of ossification of the blocks. Some parts of the xenograft were encased in soft tissue, partly surrounded by multinuclear giant cells. However, all groups showed obvious signs of bone/graft resorption.
Within the limits of the present study, it was concluded that the examined screwable xenogenous bone block might be a useful scaffold for ridge augmentation procedures. However, the combination of xenogenous blocks with a cross-linked collagen membrane did not appear to improve outcomes.
Background:
Regenerative periodontal therapy aims to predictably restore the tooth's supporting periodontal tissues and should result in formation of a new connective tissue attachment (i.e. new cementum with inserting periodontal ligament fibres) and new alveolar bone. Histologic evidence from preclinical models has demonstrated periodontal regeneration following treatment with barrier membranes, various types of grafting materials or a combination thereof. However, it is still not clear to what extent a combination of barrier membranes and grafting materials may additionally enhance the regeneration process compared with barrier membranes alone, grafting materials alone or open flap debridement.
Objectives:
To review with a systematic approach all preclinical (i.e. animal) studies presenting histologic support for periodontal regeneration using the combination of barrier membranes and grafting materials.
Material and methods:
Based on a focused question, an electronic and manual search was conducted for animal studies presenting histological data for the effect of the combined use of barrier membranes and grafting materials on the treatment of periodontal defects. A systematic approach was followed by two independent reviewers including eligibility criotateria for study inclusion, outcome measures determination, screening method, data extraction, data synthesis and drawing of conclusions.
Results:
Ten papers completely fulfilling the inclusion criteria were selected. All relevant data from the selected papers were extracted and recorded in separate tables according to the types of periodontal defects treated (i.e. supra-alveolar defects, intrabony defects, furcation defects and fenestration defects) with the combination of barrier membranes and grafting materials. Most studies have demonstrated periodontal regeneration following the combination approach. Most studies demonstrated superior histologic healing following the combination of barrier membranes and grafting materials than following open flap debridement. Histologically superior healing following the combination of barrier membranes and grafting materials when compared with barrier membranes alone or grafting materials alone were only obtained in non-contained two wall intrabony and supraalveolar defects.
Conclusion:
Within its limits the present analysis indicates that: (a) The combination of barrier membranes and grafting materials may result in histological evidence of periodontal regeneration, predominantly bone repair. (b) No additional benefits of combination treatments were detected in models of three wall intrabony, Class II furcation or fenestration defects. (c) In supra-alveolar and two wall intrabony (missing buccal wall) defect models of periodontal regeneration, the additional use of a grafting material gave superior histological results of bone repair to barrier membranes alone. (d) In one study using a supra-alveolar model, combined graft and barrier membrane gave a superior result to graft alone.
The aim of the present study was to investigate the effects of surface hydrophilicity and microtopography on soft and hard tissue integration at non-submerged titanium implants.
Implantation of conventional sand-blasted large grit and acid-etched (SLA) and chemically modified SLA (modSLA) titanium implants with differently structured transmucosal surfaces (SLA implants: machined [M-SLA] or SLA [SLA-SLA]; modSLA implants: mod acid-etched [modA] [modA-modSLA] or modSLA [modSLA-modSLA]) was performed bilaterally in the upper and lower jaws of 15 beagle dogs. The animals were sacrificed after 1, 4, 7, 14, or 28 days. Tissue reactions were assessed histomorphometrically and immunohistochemically using monoclonal antibodies to transglutaminase II (angiogenesis) and osteocalcin.
Although the junctional epithelium commonly was separated from M-SLA and SLA-SLA implants by a gap, the epithelial cells appeared to be in close contact with modA-modSLA surfaces after 14 days of healing. Moreover, modA-modSLA and modSLA-modSLA groups showed a well-vascularized subepithelial connective tissue exhibiting collagen fibers that started to extend and attach partially perpendicular to the implant surface. The highest and statistically significant mean bone-to-implant contact areas were observed in the modA-modSLA and modSLA-modSLA groups at days 7, 14, and 28.
Within the limits of this study, it may be concluded that soft and hard tissue integration was influenced mainly by surface hydrophilicity rather than by microtopography.
Objectives:
To assess biomechanical, micro-computed tomographic (micro CT) and immunohistochemical characteristics of early osseous integration at titanium implants placed following lateral ridge augmentation using autogenous extracted tooth roots.
Material & methods:
The roots of healthy maxillary premolars (PM) and retromolar cortical autogenous bone (AB) blocks were used for lateral ridge augmentation at chronic-type defects in the lower quadrants of n = 16 foxhounds. At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Osteocalcin (OC) antigen reactivity, removal torque values (RT) and the bone volume per tissue volume (micro CT- BV/TV) along the implants were assessed.
Results:
Median OC (PM: 6.71 vs. AB: 2.73%), RT (PM: 61.97 vs. AB: 44.8 Ncm) and BV/TV (PM: 0.34 vs. AB: 0.21) values were comparable in both PM and AB groups.
Conclusions:
PM and AB grafted sites equally supported the early stages of osseointegration.
Objectives:
To assess the efficacy of tooth roots used as autografts for lateral ridge augmentation and two-stage early osseointegration of titanium implants.
Material & methods:
The maxillary premolars were randomly assigned to either endondontic therapy (PM-E) or were left untreated (PM-C). Retromolar cortical autogenous bone (AB) blocks served as controls. PM-E/ PM-C and AB were used for ridge augmentation at chronic-type defects in both lower quadrants (n=8 foxhounds). At 12 weeks, titanium implants were inserted and left to heal for another 3 weeks. Histological analyses considered crestal ridge width - CW; augmented area - AA and bone-to-implant contact - BIC.
Results:
Both PM and AB grafts (exposures: AB=3; PM-C=4; PM-E=7) were gradually involved in the bone remodeling process and associated with a replacement resorption. Median CW (PM-C: 2.70 vs. AB: 3.30 mm; PM-E: 2.96 vs. AB: 3.35 mm), AA (PM-C: 7.55 vs. AB: 8.56 mm(2) ; PM-E: 11.20 vs. AB: 6.60 mm(2) ) and BIC (PM-C: 36.96 mm vs. AB: 64.10%; PM-E: 50.79 vs. AB: 32.53%) values were comparable in both PM and AB groups (p>0.05, respectively).
Conclusions:
Extracted tooth roots revealed a structural and biological potential to serve as an alternative autograft to autogenous bone. A higher exposure rate may be expected when using endodontically treated teeth. This article is protected by copyright. All rights reserved.
Intrabony periodontal defects are a frequent complication of periodontitis and, if left untreated, may negatively affect long-term tooth prognosis. The optimal outcome of treatment in intrabony defects is considered to be the absence of bleeding on probing, the presence of shallow pockets associated with periodontal regeneration (i.e. formation of new root cementum with functionally orientated inserting periodontal ligament fibers connected to new alveolar bone) and no soft-tissue recession. A plethora of different surgical techniques, often including implantation of various types of bone graft and/or bone substitutes, root surface demineralization, guided tissue regeneration, growth and differentiation factors, enamel matrix proteins or various combinations thereof, have been employed to achieve periodontal regeneration. Despite positive observations in animal models and successful outcomes reported for many of the available regenerative techniques and materials in patients, including histologic reports, robust information on the degree to which reported clinical improvements reflect true periodontal regeneration does not exist. Thus, the aim of this review was to summarize, in a systematic manner, the available histologic evidence on the effect of reconstructive periodontal surgery using various types of biomaterials to enhance periodontal wound healing/regeneration in human intrabony defects. In addition, the inherent problems associated with performing human histologic studies and in interpreting the results, as well as certain ethical considerations, are discussed. The results of the present systematic review indicate that periodontal regeneration in human intrabony defects can be achieved to a variable extent using a range of methods and materials. Periodontal regeneration has been observed following the use of a variety of bone grafts and substitutes, guided tissue regeneration, biological factors and combinations thereof. Combination approaches appear to provide the best outcomes, whilst implantation of alloplastic material alone demonstrated limited, to no, periodontal regeneration.
© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Purpose:
Different forms of dentin, including untreated, undemineralized, demineralized, boiled, or mixed with other materials, have been evaluated for efficacy as bone substitutes. However, the effects of application of liquid nitrogen-treated dentin for bone grafting remain unknown. The objective of this study was to chronologically evaluate bone healing following grafting with liquid nitrogen-treated dentin in a rabbit model.
Materials and methods:
Autogenous dentin treated with liquid nitrogen at -196°C for 20 minutes was used. In 16 New Zealand White rabbits, a bone defect (5 mm in diameter) was created in each femur and randomly grafted with either autogenous dentin (experimental group) or autogenous bone grafts (positive control). In another four rabbits (negative control), a similar defect in each femur was left empty. The rabbits were sacrificed at 2, 4, 8, and 12 weeks. Explants of grafted sites were harvested for histologic and histomorphometric analysis.
Results:
At 2 and 4 weeks in both the experimental and positive control groups, accelerated formation of new bone was observed, which was undergoing remodeling at 8 and 12 weeks. The mean new bone score was higher in the experimental than in the negative control groups, but this was not statistically significant.
Conclusion:
The present results demonstrated that liquid nitrogen-treated autogenous dentin has both osteoconductive and osteoinductive properties and therefore has potential as a bone substitute.
To histologically and immunologically assess experimental peri-implant mucositis at surface enhanced modified (mod) hydrophilic titanium implants.
In a split-mouth design (n=6 foxhounds), 4 different implants were inserted on each side of the maxilla: 3 titanium-zirconium alloy implants (TiZr) with either modSLA (sand-blasted, acid etched and chemically modified), modMA (machined, acid etched and chemically modified), or M (machined) surfaces in the transmucosal portion, and one titanium implant with a machined transmucosal portion (TiM). Experimental mucositis was induced at one randomly assigned side (NPC), while the contralateral maxillary side received mechanical plaque removal 3 times per week (PC). At 16 weeks, tissue biopsies were processed for histological (primary outcome: apical extension of the inflammatory cell infiltrate measured from the mucosal margin - PM-aICT) and immunohistochemical (CD68 antigen reactivity) analyses. Peri-implant sulcus fluid (PISF) was analysed for interleukin (IL)-1β, IL-8, matrix metalloproteinase (MMP)-8, and myeloperoxidase (MPO).
Mean PM-aICT values varied between 1.86 (TiZrmodSLA) and 3.40 mm (TiM) in the UPC group, and between 0.88 (TiZrmodSLA) and 2.08 mm (TiZrM) in the PC group. Mean CD68, IL-1β, IL-8, MMP-8, and MPO values were equally distributed between mod- and control implants in both NPC and PC groups.
The progression of experimental mucositis was comparable at all implant surfaces investigated. This article is protected by copyright. All rights reserved.
Microvascular supply is of fundamental importance to the survival and integration of grafting. Since the autogenous bone is still the gold standard for osseous augmentation, the aim of this study was to analyze the initial osseous, angiogenic and inflammatory response and subsequent osseointegration after implantation of dentin and beta-tricalcium phosphate (ß-TCP) scaffolds into the calvaria chamber of balb/c mice comparing with bone. The vascularisation of perforated implants of dentin (n=8), ß-TCP (n=8) and isogenic calvarial bone (n=8) displaying pores similar in size and structure was analyzed in vivo using intravital fluorescence microscopy. In additional animals (n=24) the osseointegration of dentin, ß-TCP and bone implants was assessed by fluorochrome sequential labelling of growing bone for up to 12 weeks. Animals without implants served as controls. Intravital fluorescence microscopy revealed that implantation of bone substitutes caused an only mild inflammatory response. Comparable to isogenic bone both dentin and ß-TCP scaffolds were found nearly completely vascularized by day 22 and osseointegrated within 12 weeks. In conclusion, dentin and ß-TCP scaffolds are similar to isogenic bone in terms of inflammatory and neovascularization response, highlighting their potential utility in regeneration of bone defects.
To evaluate radiological bone level (RBL) (i.e. cone-beam computed tomography) and histological bone levels (HBL) as well as re-osseointegration [bone-to-implant contact (BIC)] after surgical resective (i.e. implantoplasty) and/or regenerative therapy of advanced ligature-induced peri-implantitis in dogs.
At all defect sites (n=6 dogs, n=48 implants), the intrabony component was filled with a particulate bovine-derived natural bone mineral (NBM). The supracrestal component was treated by either the application of an equine bone block (EB) or implantoplasty. In a split-mouth design, NBM and EB were soak-loaded with recombinant human bone morphogenetic protein (rhBMP)-2 or sterile saline. All sites were covered by a native collagen membrane and left to heal in a submerged position for 12 weeks.
A premature wound exposure was observed at nine defect sites. Mean RBL and HBL values were lowest in the P+rhBMP-2 group, reaching statistical significance when compared with the EB group. Mean BIC values were comparable in all groups. Within-group comparisons commonly revealed a close correlation between RBL and HBL values.
It was concluded that (i) in all groups the investigations failed to predictably obtain complete defect resolution, (ii) the surgical procedure was associated with high exposure rates, and (iii) RBL was closely correlated with HBL.
After trauma and losses of teeth, bone augmentation with bone grafts or bone replacement material is sometimes required before implant treatment. The ideal bone replacement material has not yet been characterized. Dentin is known to undergo ankylosis and replacement resorption after replantation of teeth. Dentin has also been shown to contain bone morphogenic protein. These properties may possibly be used making dentin an alternative or supplement to bone grafting to defect areas prior to treatment with osseointegrated implants. The aim of this study was to investigate if dentin is ankylosed and replaced by newly formed bone when transplanted to bone defects.
Ten New Zealand rabbits were used for the experiment. The rabbits were subjected to surgical exposure and preparation of bone cavities in the tibia bilaterally. Dentin blocks from human premolars extracted for orthodontic reasons were used as grafts. Dentin blocks were inserted in the cavities penetrating into the marrow space in 16 tibias. Four tibias were prepared with the same cavities, but without being subjected to dentin grafting and served as controls. Five rabbits were sacrificed after 3 months and five rabbits after 6 months. Histological processing and evaluation were performed and tissue conditions evaluated. The area of ankylosis was estimated.
All dentin blocks healed with ankylosis in contact with bone without inflammatory reactions. In the cortical regions of the tibia, fusion of bone with dentin was seen in 86% of the dentin surface after 3 months and 98% after 6 months. On the dentin blocks inserted into the marrow space, bone was formed on the dentin block on average covering 51% of the dentin after 3 months and covering 77% after 6 months. Resorption of the dentin was seen to a larger extent after 6 months with osseous replacement in the resorption cavities.
Dentin xenografts have a potential to be incorporated in bone without inflammation and gradually resorbed and replaced by new bone.
The aim of the present study was to histologically evaluate and compare a new prototype collagen type I/III-containing equine- (EB) and a bovine- (BB) derived cancellous bone block in a dog model.
Four standardized box-shaped defects were bilaterally created at the buccal aspect of the alveolar ridge in the lower jaws of five beagle dogs and randomly allocated to either EB or BB. Each experimental site was covered by a native (non-crosslinked) collagen membrane and left to heal in a submerged position for 12 weeks. Dissected blocks were processed for semi-/and quantitative analyses.
Both groups had no adverse clinical or histopathological events (i.e. inflammatory/foreign body reactions). BB specimens revealed no signs of biodegradation and were commonly embedded in a fibrous connective tissue. New bone formation and bony graft integration were minimal. In contrast, EB specimens were characterized by a significantly increased cell (i.e. osteoclasts and multinucleated giant cells)-mediated degradation of the graft material (P<0.001). The amount and extent of bone ingrowth was consistently higher in all EB specimens, but failed to reach statistical significance in comparison with the BB group (P>0.05).
It was concluded that the application of EB may not be associated with an improved bone formation than BB.
Dentin contains bone morphogenic protein which is important in bone induction and dentin can act as a slow releasing carrier. This property may possibly be used as an alternative or supplement to bone grafting to defective areas after trauma prior to treatment with osseointegrated implants. Hence, the objective of this study was to investigate if dentin can be used as a graft in bone defects in an experimental rabbit model.
Eight New Zealand White Rabbits were used to prepare bone cavities either in the angle of the mandible or tibia. Six of the eight tibial and six of the eight mandibular bone defects were filled with dentin blocks from human premolars which were extracted for orthodontic treatment. Two mandibular and two tibial bone cavities were used as controls and all the rabbits were sacrificed after 3 months. Radiographic and histological examinations were performed.
There was a difference in healing pattern between the mandibular and tibial defects. In the mandible, the dentin blocks were resorbed to a larger extent and more often surrounded by fibrous tissue, probably due to the fact that the dentin blocks were mobile because of the thin mandibles and muscular activity in that area. Only some dentin blocks were ankylosed with the mandibular bone. In the tibia however, all dentin blocks were fused to bone over a large area. Osseous replacement resorption was seen. In control cavities, bone formation was seen but was never complete. No signs of inflammatory changes were seen in any fused grafts.
Dentin grafts have a potential to be incorporated in bone without inflammation and can be used as bone inducer and later replaced by bone. Thus, rabbit tibia served as a better model for further studies of this phenomenon when compared to the mandible.
The purpose of this article is to delineate the fate of bone transplants by presenting: some general information on the microscopy of autogenous bone transplant repair; the mechanisms of bone allograft rejection; and some possible alternatives when autogenous bone is insufficient.
Dentin may be regarded as a mineralized connective tissue. In its composition as well as its mode of formation, dentin exhibits several similarities with bone, but also definite differences. The dentin organic phase, the matrix, determines its morphology and is believed to be instrumental in the formation of the mineral phase. A fibrous web of collagen type I dominates the organic matrix. Also, minor amounts of other collagen types may be present. The noncollagenous proteins (NCPs), which constitute about 10% of the matrix, fall into several categories: phosphoproteins, Gla-proteins of the osteocalcin type as well as matrix Gla-protein, proteoglycans, different acidic glycoproteins, and serum proteins. Some of these NCPs have unique chemical compositions that give them specific properties. Dentinogenesis occurs by two simultaneous processes: the formation of a collagenous web in predentin, which is followed by the formation of the inorganic phase at the mineralization front. The composition of the predentin organic matrix differs from that of dentin, as some NCP components are secreted extracellularly just in advance of the mineralization front. In addition, some constituents of predentin seem to be metabolized. The NCPs may be important to several processes during dentinogenesis. Much evidence indicates that noncollagenous components in the matrix are instrumental in mineral formation. New data show that polyanionic NCPs, such as phosphoprotein and proteoglycans, when immobilized on a solid support, induce apatite formation under physiological conditions. These data indicate that polyanionic NCPs may function as mineral nucleators in vivo. They may also act as size and rate regulators for crystallization and promote calcium ion diffusion in the tissue. In addition, NCPs may regulate collagen fibrillogenesis.
The bone morphogenetic properties of implants of autogenic demineralized dentin were evaluated. The dentin matrix was implanted as small pieces and as thin slices in experimental mandibular osseous defects in dogs. The dentin implants were obtained from mandibular incisor teeth from the same dogs used in the experiment. Experimental interradicular osseous defects were surgically created in the mandibular premolars areas. 2 of the 3 defects were filled with either pieces or slices of prepared dentin. The 3rd defect served as an unfilled control. The results indicate that all demineralized autogenic dentin implants induce bone formation. There was an increase in the osteogenic capacity of the implant when the samples were used as thin slices. The slices of dentin matrix give no evidence of resorption and were readily incorporated into the new bone deposited. The end product was represented by a trabecular bone joined to the dentin matrix slices. In the case of the small piece samples, the specimens were readily resorbed and replaced by new deposits of cancelous bone. The osteogenic capacity of the small piece samples of the dentin matrix is less efficient comparable to the thin slice samples of the same implant material.
The aim of the present study was to characterize the composition of the organic matrix in alveolar jaw bone and dentine using antibodies against pro-collagens Types I and III and collagens Types IV, V, and VI. After demineralization of oral hard tissues in 0.2 N HCl, antigenicity was well preserved and the distribution of the pro-collagens and collagens could be demonstrated. Staining for pro-collagen Type I was prominent around osteoblasts and in pre-dentine, indicating active de novo synthesis of Type I pro-collagen. Pro-collagen Type I was ubiquitous but was less abundant in bone and dentine, whereas pro-collagen Type III was seen only in areas of bone remodeling, in peritubular spaces, and in pre-dentine. Type IV collagen was limited to the basement membranes of vessels in osteons and bone marrow. Type V collagen was detected neither in pre-dentine nor in bone. In contrast, Type VI collagen was found in dentine and bone, showing a faint but homogeneous staining which, similarly to pro-collagen Type III, was pronounced around osteoblasts and in pre-dentine, areas of active bone and dentine formation. This study showed that the organic matrix of dentine and bone contains Type VI as well as Type I collagen. Pro-collagen Type III (and to a lesser extent collagen Type VI) is transiently produced during new formation and remodeling of oral hard tissues, and disappears once the matrix calcifies. Type I pro-collagen qualifies as a general marker protein for increased osteoblastic activity. We conclude that immunostaining for the different collagen/pro-collagen types can be used to assess normal or abnormal stages of bone/dentine formation.
Cancellous and cortical autografts histologically have three differences: (1) cancellous grafts are revascularized more rapidly and completely than cortical grafts; (2) creeping substitution of cancellous bone initially involves an appositional bone formation phase, followed by a resorptive phase, whereas cortical grafts undergo a reverse creeping substitution process; (3) cancellous grafts tend to repair completely with time, whereas cortical grafts remain as admixtures of necrotic and viable bone. Physiologic skeletal metabolic factors influence the rate, amount, and completeness of bone repair and graft incorporation. The mechanical strengths of cancellous and cortical grafts are correlated with their respective repair processes: cancellous grafts tend to be strengthened first, whereas cortical grafts are weakened. Bone allografts are influenced by the same immunologic factors as other tissue grafts. Fresh bone allografts may be rejected by the host's immune system. The histoincompatibility antigens of bone allografts are presumably the proteins or glycoproteins on cell surfaces. The matrix proteins may or may not elicit graft rejection. The rejection of a bone allograft is considered to be a cellular rather than a humoral response, although the humoral component may play a part. The degree of the host response to an allograft may be related to the antigen concentration and total dose. The rejection of a bone allograft is histologically expressed by the disruption of vessels, an inflammatory process including lymphocytes, fibrous encapsulation, peripheral graft resorption, callus bridging, nonunions, and fatigue fractures.
The pathogenesis and topography of replacement root resorption (ankylosis) after replantation of incisors was examined in green Vervet monkeys (Cercopithecus aethiops). Incisors were replanted after 0,18 or 120 min. storage and examined histometrically for replacement resorption after 2, 4 and 8 weeks. There was a significant preference for certain locations upon the root surface. Thus, ankylosis was found significantly more often on the rounded labial and lingual surfaces than on the flat or concave proximal surfaces, and on the apical portion of the root in contrast to the coronal portion. At two-weeks' observation periods, two types of initial ankylosis were seen after 120 min. dry storage. In the cervical areas and on the labial and lingual surfaces, the most common finding was a complete mineralization of the entire periodontal ligament, while on the remaining parts of the root surface, the initial ankylosis area consisted of a layer of bone deposited upon the root surface and socket wall with an intervening soft connective tissue zone. These two zones were in some areas united by bony bridges formed along the Sharpey's fiber bundles. It is suggested that the first type of initial ankylosis represents areas where both the cemental and alveolar parts of the periodontal ligament are avital; whereas the second type represents areas where only the cemental part of the periodontal ligament is avital (i.e., from dry storage). It is concluded that ankylosis after replantation is presumably a response in the periodontium to areas of the periodontal ligament and/or the root surface damaged by the extraction procedure or storage conditions prior to replantation.
The aim of the present pilot study was to investigate initial and early tissue reactions to modified (mod) and conventional sand-blasted, large grit and acid-etched (SLA) titanium implants.
Implantation of modSLA and SLA implants was performed bilaterally in both the mandible and maxilla of dogs. The animals were sacrificed after a healing period of 1, 4, 7 and 14 days, respectively. Peri-implant tissue reactions were assessed in non-decalcified tissue sections using conventional histology (Toluidine blue-TB and Masson Goldner Trichrome stain-MG) and immunohistochemistry using monoclonal antibodies to transglutaminase II (TG) (angiogenesis) and osteocalcin (OC). Bone density (BD) and bone to implant contact (BIC) were assessed histomorphometrically.
Day 1 revealed an early TG antigen reactivity in the provisional fibrin matrix adjacent to both implant surfaces. Day 4 was characterized by the formation of a collagen-rich connective tissue (MG), which revealed the first signs of OC synthesis adjacent to modSLA surfaces. Immunohistochemical staining for TG revealed a direct correlation between angiogenesis and new bone formation, which was clearly identifiable after 7 days by means of increasing BD, BIC and OC values. After 14 days, modSLA surfaces seemed to be surrounded by a firmly attached mature, parallel-fibered woven bone.
Within the limits of the present study, it might be concluded that the combination of immunohistochemical and conventional histological stainings in non-decalcified tissue sections is a valuable technique to evaluate the initial and early stages of wound healing around endosseous titanium implants.
The aim of the present study was to immunohistochemically evaluate lateral ridge augmentation using a particulated (BOG) or block (BOB) natural bone mineral biocoated with rhGDF-5 and rhBMP-2 in dogs.
Three standardized box-shaped defects were surgically created at the buccal aspect of the alveolar ridge in each quadrant of eight beagle dogs. After 2 months of healing, the chronic-type defects were randomly allocated in a split-mouth design to either (i) BOG or (ii) BOB biocoated with (a) rhGDF-5 or (b) rhBMP-2, respectively. Uncoated grafts served as controls. After 3 and 8 weeks, dissected blocks were prepared for immunohistochemical [osteocalcin (OC)] and histomorphometrical analysis [e.g. area (mm(2)) of new bone fill (BF), newly formed mineralized (MT) and non-mineralized tissue (NMT)].
rhBMP-2 biocoated BOG revealed significantly highest BF and MT values at 3 (upper and lower jaws - UJ/LJ - compared with BOG) and 8 weeks (UJ - compared with rhGDF-5). Biocoating of BOB using both rhGDF-5 and rhBMP-2 resulted in significantly increased MT values at 8 weeks (UJ/LJ - compared with BOB). In all groups, NMT adjacent to BOG and BOB scaffolds revealed pronounced signs of an OC antigen reactivity.
Within the limits of the present study, it was concluded that both rhGDF-5 and rhBMP-2 have shown efficacy; however, their bone regenerative effect was markedly influenced by the carrier.
Animal research: reporting in vivo experiments: the ARRIVE guidelines
- Kilkenny