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Radiographic outcomes following lateral alveolar ridge augmentation using autogenous tooth roots

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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.
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R E S E A R C H Open Access
Radiographic outcomes following lateral
alveolar ridge augmentation using
autogenous tooth roots
Puria Parvini
1
, Robert Sader
2
, Didem Sahin
3
, Jürgen Becker
3
and Frank Schwarz
1,3*
Abstract
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 (mm
2
) (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 mm
2
(median 18.83) in the TR group
and 79.67 ± 15.66% (median 78.85) and 12.42 ± 10.11 mm
2
(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.
Keywords: Clinical study, Alveolar ridge augmentation, Tooth transplantation
Background
Autogenous bone (AB) blocks harvested from intraoral
donor sites (i.e., retromandibular, chin) are the most
commonly used procedure for lateral alveolar ridge aug-
mentation [1]. However, despite significant horizontal
bone gains, cortical bone blocks were noted to undergo
an incomplete replacement resorption [2,3], thus featur-
ing a composition of non-vital residual and newly
formed vital bone in the former defect area [4]. More-
over, AB blocks are prone to a rapid degradation and
therefore commonly combined with contour augmenta-
tion procedures using slowly resorbing particulate grafts
and barrier membranes [5].
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 al-
veolar 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 retromo-
lar AB grafts [4,6,7]. The median bone-to-implant con-
tact (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].
These preclinical data have recently been in an initial hu-
man case report [8]aswellasinaprospectivecontrolled
clinical study [9]. In particular, soft tissue healing was un-
eventful in both TR and AB groups. The crestal ridge width
at 26 weeks (CW26) amounted to 10.06 ± 1.85 mm
(median 11.0) in the TR group and 9.20 ± 2.09 mm
* Correspondence: f.schwarz@med.uni-frankfurt.de
1
Department of Oral Surgery and Implantology, Carolinum, Johann Wolfgang
Goethe-University, Frankfurt, Germany
3
Department of Oral Surgery, Universitätsklinikum Düsseldorf, Düsseldorf,
Germany
Full list of author information is available at the end of the article
International Journal o
f
Implant Dentistry
© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
Parvini et al. International Journal of Implant Dentistry (2018) 4:31
https://doi.org/10.1186/s40729-018-0142-6
(median 8.50) in the AB group and allowed for a successful
implant placement in all patients investigated [9].
The aim of the present analysis was to assess and com-
pare the radiographic outcomes in both groups.
Methods
Study design and participants
This analysis was based on the radiographic (i.e.,
cone-beam computed tomographicCBCT) data de-
rived from a prospective controlled clinical monocenter
study including a total of 30 patients [9]. Each partici-
pant exhibited either a tooth gap or a free-end situation
with an inadequate horizontal ridge width and was in
need of an implant-supported fixed restoration.
In brief, lateral ridge augmentation was conducted
according to a standardized procedure under local
anesthesia [8].
One group of patients (n= 15; mean age 41.93 years;
range 19 to 60 years) exhibited either one or more
caries-free partially/fully retained or impacted wisdom
teeth without signs of local pathologies (e.g., cysts). TR
grafts were separated (i.e., crown decapitation, vertical
separation of multi-rooted teeth, preservation of the ex-
posed pulp) from the extracted/surgically removed teeth
and adapted in size and shape to match the defect area. At
the respective downward aspect of the TR graft, the layer
of cementum was carefully removed using a diamond bur
to facilitate ankylosis at the recipient site [4].
Due to the absence of any suitable wisdom teeth, an-
other group of patients (n= 15; mean age 44.53 years;
range 21 to 60 years) was allocated to the harvesting of
monocortical block grafts from the linea obliqua. Both
TR and AB grafts were rigidly fixed using one to two
titanium osteosynthesis screws (1.5 × 9 mm, Medicon,
Tuttlingen, Germany) after gently flattening the re-
cipient site using a round carbide bur underwater
(i.e., sterile saline) cooling.
Advancement of the mucoperiosteal flaps was achieved
using periosteal-releasing incisions. The coronally reposi-
tioned flaps were fixed using vertical double sutures to
allow for a submerged healing period of 26 weeks (Fig. 1).
All patients had received a perioperative antibiotic
(1× amoxicillin 2 g) as well as a peri- and postopera-
tive (2 days) antiphlogistic prophylaxis (prednisolon,
total of 40 mg). Analgetics (ibuprofen 600 mg) were
provided according to individual needs.
The study outline and the follow-up visits are summa-
rized in Table 1[9].
Fig. 1 Lateral ridge augmentationa surgical procedure in the AB and TR groups. aThe retromolar area served as a donor site for the harvesting
of monocortical bone blocks in the AB group. bAB blocks were shaped to match the size and configuration of the defect site and fixed using
one central osteosynthesis screw. cTR grafts were separated from either partially/fully retained or impacted wisdom teeth. dThe most suitable
specimen was positioned and fixed in a way that the exposed dentin faced the defect area, thus facilitating ankylosis at the recipient site. The
crestal perforations were derived from initial attempts to pre-drill the osteosynthesis screw. All sites were left to heal in a submerged position
without providing any contour augmentation procedures
Parvini et al. International Journal of Implant Dentistry (2018) 4:31 Page 2 of 6
Ethics, consent, and permissions
Each patient was given a detailed description of the
study procedures and signed a consent to participate.
The study protocol was approved by the ethics commit-
tee (4837R) of the Heinrich Heine University, Düssel-
dorf, Germany, and registered via the Internet Portal of
the German Clinical Trials Register (DRKS00009586).
The present reporting considered the checklist items
as proposed in the STROBE statement.
Inclusion and exclusion criteria
The inclusion criteria considered the following condi-
tions: (1) age 18 to 60 years; (2) candidate for lateral
ridge augmentation; (3) insufficient bone ridge width as-
sociated with a non-contained defect at the recipient site
for implant placement, as evidenced intraoperatively; (4)
sufficient bone height at the recipient site for implant
placement, as evidenced in a preoperative panoramic
radiograph; and (5) healthy oral mucosa, at least 3 mm
keratinized tissue.
The exclusion criteria included the following condi-
tions: (1) general contraindications for dental and/or
surgical treatments; (2) inflammatory and autoimmune
disease of the oral cavity; (3) uncontrolled diabetes
(HbA1c > 7%); (4) history of malignancy requiring
chemotherapy or radiotherapy within the past 5 years;
(5) previous immunosuppressant, bisphosphonate, or
high-dose corticosteroid therapy; (6) smokers; and (7)
pregnant or lactating women [9].
Clinical assessments
The clinical width (CW) of the alveolar ridge immediately
before the augmentation (CWb) was assessed to the near-
est 0.25 mm by means of a caliper. This was positioned at
2 mm below the crest at the most central aspect of the re-
spective defect site, whose vertical plane was marked by
the osteosynthesis screw. Measurement of CW was re-
peated immediately after augmentation (CWa). Graft
thickness (GT) was calculated as CWa CWb.
Radiographic assessments
According to the clinical standard procedure, CBCT scans
(25 patients: PaX-i3D Green, Orangedental, Biberach,
Germany, at 95 kV, 8.59.0 mAs; 5 patients: ProMax3D,
Planmeca, Helsinki, Finland, at 90 kV, 5.69.0 mAs) using
adjusted fields of view (i.e., 5 × 5 and 8 × 5 cm) were taken
at 26 weeks for preoperative implant planning at the
respective sites.
Images of the coronal planes representing the most
central aspect of the respective defect sites were
exported and analyzed for the basal graft integration
(BI26) and the cross-sectional grafted area (mm
2
)
(SA26) (ImageJ). In particular, BI26 was measured as a
percentage AB/TR to host bone contact along the basal
graft extension serving as 100%, respectively (Fig. 2).
All measurements were performed by one previously
calibrated investigator.
Sample size calculation and statistical analysis
The sample size calculation considered a standard nor-
mal distribution (type I error set at .05; type II error set
at .20) and a sigma which was estimated based on the
standard deviations observed in a recent preclinical ani-
mal study [4]. The clinical width of the alveolar ridge
was defined as the primary outcome variable, considering
a clinically relevant difference of 2 mm. A sample size of
Table 1 Study design and follow up visits
Visit 1 Visit 2 Visit 3 Visit 4 Visit 5 Visit 6
Recruitment Surgery Re-entry
D0 D10 W4 W13 W26
Dday, Wweek
Fig. 2 Radiographic assessments. Images of the coronal planes
representing the most central aspect of the respective defect sites
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 (mm
2
) (SA26)
Parvini et al. International Journal of Implant Dentistry (2018) 4:31 Page 3 of 6
15 patients per group was calculated to achieve a 95%
power (Power and Precision, Biostat, Englewood, USA).
The statistical analysis of the pseudonymized data sets
was accomplished using a commercially available soft-
ware program (IBM SPSS Statistics 24.0, IBM Corp.,
Armonk, NY, USA).
Mean values, standard deviations, medians, 95% confi-
dence intervals (CI), and frequency distributions were calcu-
lated for all outcomes assessed. The data rows were
examined with the Shapiro-Wilk test for normal distribu-
tion. Between-group comparisons were accomplished using
the unpaired ttest. Linear regression analyses were used to
depict the relationship between BI26 and CWb as well as
SA26 values in both groups. The alpha error was set at 0.05.
Results
Mean CWb and GT values were comparable in both
groups and amounted to 4.53 ± 1.54 mm (median
4.50; 95% CI 3.68, 5.38) and 5.66 ± 1.75 mm (median
5.0; 95% CI 4.69, 6.64) in the TR group and 5.26 ±
1.25 mm (median 5.00; 95% CI 4.57, 5.95) and 4.96 ±
1.75 mm (median 5.0; 95% CI 4.24, 5.68) in the AB
group, respectively. Between-group differences did not
reach statistical significance.
Radiographic performance endpoints
Mean SA26 values were 12.42 ± 10.11 mm
2
(median
11.36; 95% CI 6.82, 18.02) in the AB group and
amounted to 22.07 ± 12.98 mm
2
(median 18.83; 95% CI
14.88, 29.26) at the TR-treated sites. The resulting differ-
ences between both groups were statistically significant
(p= 0.031).
Mean BI26 values amounted to 79.67 ± 15.66% (me-
dian 78.85; 95% CI 70.99, 88.34) in the AB group and
tended to be lower at the TR-treated sites, revealing a
mean value of 69.26 ± 26.01% (median 72.44; 95% CI
53.85, 82.66) (Fig. 3). These differences, however, failed
to reach statistical significance (p= 0.157) (Table 2).
Regression analysis
In both groups investigated, the linear regression ana-
lysis failed to reveal any significant correlations between
BI26 and CWb (TR: Coef. 1.106; R
2
= 0.003; p= 0.851;
AB: Coef. 0.410; R
2
= 0.002; p= 0.886) or BI26 and
SA26 (TR: Coef. 0.619; R
2
= 0.058; p= 0.387; AB: Coef.
0.311; R
2
= 0.066; p= 0.354) values, respectively (Fig. 4).
Discussion
The present analysis aimed at assessing and comparing
CBCT outcomes following lateral alveolar ridge augmen-
tation using TR and AB grafts. After a healing period of
26 weeks, it was observed that TR grafts were associated
with significantly higher mean SA26 values when com-
pared with the AB group. A similar tendency was also
noted for mean BI26 values; however, this difference did
not reach statistical significance.
Fig. 3 Representative CBCT outcomes at 26 weeks. a,bTR graft. c,dAB graft
Parvini et al. International Journal of Implant Dentistry (2018) 4:31 Page 4 of 6
When interpreting these results, it must be kept in
mind that both groups were associated with comparable
CWb and GT values at baseline. However, the clinical
re-entry at 26 weeks revealed that mean CW values
amounted to 10.06 ± 1.85 mm (median 11.0; 95% CI
9.03, 11.09) in the TR group and 9.20 ± 2.09 mm (me-
dian 8.50; 95% CI 8.04, 10.35) in the AB group,
respectively. This was associated with a significantly
higher gain in ridge width of 5.53 ± 1.88 mm (median
5.00; 95% CI 4.48, 6.57) at TR- over the AB-treated sites
(3.93 ± 1.41 mm; median 4.00; 95% CI 3.15, 4.71) [9].
This difference was mainly due to a lower graft resorp-
tion in the TR group, which was basically confirmed
by the present analysis of SA26 values. Moreover, a
recent animal study employing both TR and AB grafts
for lateral alveolar ridge augmentation also corrobo-
rates, at least in part, the differences in mean SA26
values noted between both groups. 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
,whereastheme-
dian 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
notedintheABgroup[6].
However, previous clinical studies suggest that the re-
sorption of AB grafts may be limited by a simultaneous
contour augmentation (e.g., application of a bovine-derived
xenograft and coverage by a native collagen membrane)
[5,10]. In particular, CBCT analyses at 10 years re-
vealed only a minor superficial resorption of about
7.7%, which corresponded to 0.38 mm [10].
Table 2 Secondary performance endpoints (in mm)
CWb GT SA26 BI26
a) TR group (n= 15 patients)
Mean 4.53 5.66 22.07* 69.26
SD 1.54 1.75 12.98 26.01
Median 4.50 5.00 18.83 72.44
95% CI 3.68,
5.38
4.69,
6.64
14.88,
29.26
53.85,
82.66
b) AB group (n= 15 patients)
Mean 5.26 4.96 12.42 79.67
SD 1.25 1.30 10.11 15.66
Median 5.00 5.00 11.36 78.85
95% CI 4.57,
5.95
4.24,
5.68
6.82, 18.02 70.99,
88.34
Comparisons between the groups (unpaired ttest): *p= 0.031
CWb clinical width of the alveolar ridge immediately before augmentation (D0)
(mm), GT graft thickness immediately after augmentation (D0) (mm), SA26
surface area at 26 weeks (W26) (mm
2
), BI26 basal integration at 26 weeks
(W26) (%)
Fig. 4 Linear regression plots to depict the relationship between BI26 and CWb/SA26 values. aCWb (TR group). bCWb (AB group). cSA26
(TR group). dSA26 (AB group)
Parvini et al. International Journal of Implant Dentistry (2018) 4:31 Page 5 of 6
When further analyzing the present data, it was also
noted that both TR and AB grafts were associated with
comparable BI26 values, thus corroborating the clinical
observation of a firm graft connection to the host bone
at 26 weeks, which allowed for a proper placement of
adequately dimensioned titanium implants at all sites in-
vestigated [9]. 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].
Conclusions
In conclusion and within its limitations, the present clin-
ical study revealed that TR grafts may be associated with
improved SA26 values following lateral alveolar ridge
augmentation.
Funding
The study was funded by a grant of the Deutsche Forschungsgemeinschaft
(DFG), Bonn, Germany. The titanium implants were provided by the Institut
Straumann, AG, Basel, Switzerland.
Availability of data and materials
The availability of raw data used and/or analyzed during the current study is
limited/restricted by general data protection regulations.
Authorscontributions
FS, RS, and JB have made substantial contributions to the study conception,
acquisition, and interpretation of data as well as manuscript preparation.
PP and DS were involved in the data acquisition, data management, and
analysis as well as the statistical analysis. All authors read and approved the
final manuscript.
Ethics approval and consent to participate
The study protocol was approved by the ethics committee (4837R) of the
Heinrich Heine University, Düsseldorf, Germany, and registered via the
Internet Portal of the German Clinical Trials Register (DRKS00009586). Each
patient was given a detailed description of the study procedures and signed
a consent to participate.
Consent for publication
Consent for publication was obtained from all participants.
Competing interests
Puria Parvini, Robert Sader, Didem Sahin, Jürgen Becker, and Frank Schwarz
declare that they have no competing interests.
PublishersNote
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Author details
1
Department of Oral Surgery and Implantology, Carolinum, Johann Wolfgang
Goethe-University, Frankfurt, Germany.
2
Department for Oral,
Cranio-Maxillofacial and Facial Plastic Surgery, Medical Center of the Goethe
University Frankfurt, Frankfurt, Germany.
3
Department of Oral Surgery,
Universitätsklinikum Düsseldorf, Düsseldorf, Germany.
Received: 11 July 2018 Accepted: 17 August 2018
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... 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]. ...
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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.
... 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]. ...
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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.
... Reasons for excluding ten studies after full-text assessment were: an experimental study in animals (n = 1) [34], less than five patients included (n = 3) [35][36][37], unspecified numbers of LARA procedures (n = 1) [38], and studies could not be excluded before meticulous reading (n = 2) [39,40]. Three studies were excluded [41][42][43], because identical patient samples with a longer observation period were presented in two of the included studies [31,33]. However, additional information's from these excluded studies are presented in the following sections. ...
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Objectives: The objective of the present systematic review was to evaluate the current knowledge of implant treatment outcome following lateral alveolar ridge augmentation with autogenous tooth block graft compared with autogenous bone block graft prior to implant placement. Material and Methods: MEDLINE (PubMed), Embase and Cochrane Library search in combination with hand-search of relevant journals was conducted including human studies published in English through December 20, 2021. Comparative and non-comparative studies assessing lateral alveolar ridge augmentation with autogenous tooth block graft were included. Quality and risk-of-bias assessment were evaluated by Cochrane risk of bias tool, Newcastle-Ottawa Scale and GRADE system. Results: One comparative study characterized by low grade and two non-comparative studies fulfilled the inclusion criteria. No significant difference in short-term implant survival, health status of the peri-implant tissue or frequency of complications between the two treatment modalities was observed. Postoperative dimensional changes of the alveolar ridge width were significant diminished with tooth block compared with bone block (P = 0.0029). Consequently, the gain in alveolar ridge width was significantly higher with tooth block, after 26 weeks (P = 0.014). However, a higher frequency of short-term peri-implant mucositis was observed with tooth block. Conclusions: Lateral alveolar ridge augmentation with tooth block seems to be a suitable alternative to bone block. However, results of the present systematic review are based on short-term studies involving small patient samples. Further long-term randomized controlled trials are therefore needed before definite conclusions can be provided about the beneficial use of tooth block compared with bone block.
... Histological analyses have shown that dentin has osteoconductive and osteoinductive properties [6][7][8][9][10][11][12][13] and is involved in the bone remodeling process [14][15][16][17]. In addition, autogenous dentin appears to have lower resorption rates than autogenous bone [18,19]. For these reasons, autogenous dentin can be considered as a viable alternative to autogenous bone. ...
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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.
... 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]. ...
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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.
... Operasyon sonrası 1 hastada greft yüzeyinde açılma ve 1 hastada hematom geliştiği rapor edilmiştir. 78 ODKG'nin yeni kemik yapımı üzerine etkisinin incelendiği bir çalışmada, 15 hastada yönlendirilmiş kemik rejenerasyonunda otojen diş kemik greftleri kullanılmıştır. Histolojik analiz için 2. ve 4. ayda doku örnekleri alınmıştır. ...
... Several studies and highly heterogeneous data have been reported regarding the techniques applied and biomaterials used for alveolar ridge augmentation. The most controversial issue in the field is the nature of the biomaterials used for augmentation [1][2][3], and also their effects on host tissues. Some augmentation techniques are complex and involve invasive procedures not well tolerated by patients [4,5]. ...
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Microscopic and molecular events related to alveolar ridge augmentation are less known because of the lack of experimental models and limited molecular markers used to evaluate this process. We propose here the chick embryo chorioallantoic membrane (CAM) as an in vivo model to study the interaction between CAM and bone substitutes (B) combined with hyaluronic acid (BH), saline solution (BHS and BS, respectively), or both, aiming to point out the microscopic and molecular events assessed by Runt-related transcription factor 2 (RUNX 2), osteonectin (SPARC), and Bone Morphogenic Protein 4 (BMP4). The BH complex induced osteoprogenitor and osteoblastic differentiation of CAM mesenchymal cells, certified by the RUNX2 +, BMP4 +, and SPARC + phenotypes capable of bone matrix synthesis and mineralization. A strong angiogenic response without inflammation was detected on microscopic specimens of the BH combination compared with an inflammatory induced angiogenesis for the BS and BHS combinations. A multilayered organization of the BH complex grafted on CAM was detected with a differential expression of RUNX2, BMP4, and SPARC. The BH complex induced CAM mesenchymal cells differentiation through osteoblastic lineage with a sustained angiogenic response not related with inflammation. Thus, bone granules resuspended in hyaluronic acid seem to be the best combination for a proper non-inflammatory response in alveolar ridge augmentation. The CAM model allows us to assess the early events of the bone substitutes–mesenchymal cells interaction related to osteoblastic differentiation, an important step in alveolar ridge augmentation.
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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.
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Alveolar ridge augmentation can be used to obtain appropriate alveolar ridge for dental implantation. A variety of bone graft materials including autogenous bone, allograft, xenograft, and alloplastic material are used in alveolar ridge augmentation. Autogenous tooth-derived bone graft material has received much attention for the past few years, because the structure and physicochemical characteristics of tooth are similar to those of bones. Compared to autogenous tooth, allogenic tooth has the advantage of extensive resources. However, the problem of cell-derived immunological rejection of allogenic tooth remains unresolved. In the present study, acellular tooth root (ATR) is obtained by an innovative combination procedure. The biocompatibility of ATR is assessed using cytotoxicity test, hemolysis test, intracutaneous reactivity test, and acute systemic toxicity test. Osseointegration is evaluated in vivo by implanting ATR into the rat tibia defect as an allograft material. The results show that the ATR has fine biocompatibility, and there is an osseointegration between ATR and bone bed at 8 weeks post operation. This study demonstrates that the ATR could be used in alveolar ridge augmentation as a kind of new tooth-derived bone graft material.
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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.
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Lateral ridge augmentation procedures are aimed to reconstruct deficient alveolar ridges or to build up peri-implant dehiscence and fenestrations. The objective of this systematic review was to assess the efficacy of these interventions by analyzing data from 40 clinical studies evaluating bone augmentation through either the staged or the simultaneous approach. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guideline for systematic reviews was used. The primary outcomes were the changes at reentry, in the ridge width, and in the vertical and horizontal dimensions of the peri-implant defect, measured in millimeters, in the staged and simultaneous approaches, respectively. The results of the meta-analysis showed, for the simultaneous approach, a statistically significant defect height reduction when all treatments were analyzed together (weighted mean difference [WMD] = -4.28 mm; 95% confidence interval: [CI] -4.88, -3.69; P < 0.01). The intervention combining bone replacement grafts with barrier membranes was associated with superior outcomes The most frequently used intervention was the combination of xenograft and bioabsorbable membrane. Similarly, for the staged approach, there was a statistically significant horizontal gain when all treatment groups were combined (WMD = 3.90 mm; 95% CI: 3.52, 4.28; P < 0.001). The most frequently used intervention was the use of autogenous bone blocks. Both treatment strategies led to high survival and success rates (>95%) for the implants placed on the regenerated sites. Nonexposed sites gained significantly more in the simultaneous and staged approaches (WMD = 1.1 and 3.1 mm). © International & American Associations for Dental Research.
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A group of 15 partially edentulous patients who needed alveolar ridge augmentation for implant placement, were consecutively treated using a two-stage technique in an outpatient environment. A total of 18 alveolar segments were grafted. During the first operation bone blocks harvested from the mandibular ramus or symphysis were placed as lateral or vertical onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 6 months of healing the flap was re-opened, the screws were removed and the implants placed. Twelve months after the first operation implant-supported fixed bridges could be provided to the patients. Mean lateral augmentation obtained at the time of bone grafting was 6.5 +/- 0.33 mm, that reduced during healing because of graft resorption to a mean of 5.0 +/- 0.23 mm. Mean vertical augmentation obtained in the 9 sites where it was needed was 3.4 +/- 0.66 mm at bone grafting and 2.2 +/- 0.66 mm at implant placement. Mean lateral and vertical augmentation decreased by 23.5% and 42%, respectively, during bone graft healing (before implant insertion). Mandibular sites showed a larger amount of bone graft resorption than maxillary sites. All the 40 implants placed were integrated at the abutment connection and after prosthetic loading (mean follow-up was 12 months). No major complications were recorded at donor or recipient sites. Soft tissue healing was uneventful, and pain and swelling were comparable to usual dentoalveolar procedures. A visible ecchymosis was present for 4 to 7 days when the bone was harvested from the mandibular symphysis. From a clinical point of view this procedure appears to be simple, safe and effective for treating localised alveolar ridge defects in partially edentulous patients.
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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.
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Background: The use of autogenous block grafts harvested from intraoral donor sites has proven to be effective for the reconstruction of horizontal bone defects.
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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.
Article
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.
Article
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.
Article
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.
Article
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.
Article
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.