Article

Influence of autoclavation on the efficacy of extracted tooth roots used for vertical alveolar ridge augmentation

Authors:
  • Carolinum, Goethe-Universität Frankfurt am Main
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Abstract

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.

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... 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. ...
... 3,5 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 The segmentation of volumes of interest (VOIs) may also help to better understand the organization of TR associated with vertical grafting procedures. ...
... In brief, the study was subdivided into three experimental phases, including defect creation (Phase 1), vertical augmentation of chronic-type defects at 12 weeks (Phase 2), and staged implant placement at 3 weeks (Phase 3). 6 All animals were fed daily with soft-food diet and offered water ad libitum. The study protocol was approved by the Landesamt für Natur und Verbraucherschutz, Recklinghausen, Germany. ...
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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.
... At the two posterior sites in each hemimandible, a staged implant placement was feasible. These data were reported in a separate analysis [11]. ...
... Significant differences between groups were, however, 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 mm 2 ] values. These data were basically within the range of the outcomes noted at the experimental sites that had received a staged implant placement at 12 weeks after vertical ridge augmentation [11]. In particular, at 3 weeks after implant placement, median GRH ranged from 1.45 (vestibular aspect-v) to 1.62 mm (oral aspect-o) in the TR-C group and from 0.97 (v) to 1.79 mm (o) in the TR-A group, respectively. ...
... Median AA values ranged from 0.64 (v) to 2.36 mm 2 (o) in the TR-C and from 0.22 (v) to 2.36 mm 2 (o) in the TR-A group, respectively. These differences between both groups did, however, not reach statistical significance [11]. When interpreting and comparing the histomorphometrical analyses of both studies, it must be kept in mind that the assessment of BD-BC (i.e., GRH) values in the latter analysis did not depict the total vertical bone gain, since implant placement was associated with the occurrence of dehiscence-type defects at either vestibular and/ or oral aspects. ...
Article
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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.
... In vivo studies of beagle's vertical alveolar ridge augmentation show equally augmented bone of autoclaved tooth and natural tooth. But bone-to-implant contact of the natural tooth is much higher than autoclaved teeth [37,38]. Unlike other studies with the re-entry of 24 to 26 weeks [14,15,20], re-entry at the 4th month in our study also witnessed a sufficient bone gain, and TS had integrated with recipient's bone. ...
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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.
Article
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.
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Vertical bone augmentation is an important challenge in dental implantology. Existing vertical bone augmentation techniques, along with bone grafting materials, have achieved certain clinical progress but continue to have numerous limitations. In order to evaluate the possibility of using biomaterials to develop bone substitutes, medical devices and/or new bone grafting techniques for vertical bone augmentation, it is essential to establish clinically relevant animal models to investigate their biocompatibility, mechanical properties, applicability and safety. The present review discusses recent animal experiments related to vertical bone augmentation. In addition, surgical protocols for establishing relevant preclinical models with various animal species were reviewed. The present study aims to provide guidance for selecting experimental animal models of vertical bone augmentation.
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There have been recent reports of successful use of fragmented autogenous dentin being used as a graft material in implant dentistry. This may reduce morbidity and the need for a second donor ste or for the use of alloplasts or allografts. This article discusses the background, preparation and use of autogenous dentin as an oral osseous graft material. A series of cases where autogenous dentin is used to graft immediate dental implant sites is presented. After 21 months one case biopsy showed only bone and no remnant dentin. Pulverized autogenous dentin may be an appropriate graft material in implant dentistry.
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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.
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The aim of this in vitro study was to determine whether different disinfection/sterilization methods affected the risk of fracture of extracted teeth used for preclinical dental education. Freshly extracted intact mandibular incisors were assigned to different groups according to the processing method used. In the autoclave group (n=20), teeth were autoclaved for 40 min at 240°F under a pressure of 20 psi; in the formalin group (n=20), teeth were immersed in 10% formalin for two weeks; and in the control group (n=10), teeth were not processed. Teeth were then stored at 4°C in distilled water until use. Endodontic procedures were performed, and the fracture strength of the specimen was subsequently tested under compressive force along the long axis of the teeth using an Instron universal testing machine. The results showed that none of the specimens fractured during endodontic procedures. However, the compressive load needed to fracture the teeth was significantly less for the autoclaved teeth than the teeth stored in formalin or the control teeth (p<0.001). The disinfection/sterilization method used affected the fracture resistance of extracted teeth: autoclaved teeth were less resistant to fracture than teeth that were not sterilized or teeth that were chemically disinfected. However, fracture resistance was not reduced enough to lead to tooth fracture during preclinical endodontic procedures. Therefore, either processing method may be appropriate for teeth to be used for preclinical endodontic training.
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With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth.
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Development of an optimal interface between bone and orthopaedic and dental implants has taken place for many years. In order to determine whether a newly developed implant material conforms to the requirements of biocompatibility, mechanical stability and safety, it must undergo rigorous testing both in vitro and in vivo. Results from in vitro studies can be difficult to extrapolate to the in vivo situation. For this reason the use of animal models is often an essential step in the testing of orthopaedic and dental implants prior to clinical use in humans. This review discusses some of the more commonly available and frequently used animal models such as the dog, sheep, goat, pig and rabbit models for the evaluation of bone-implant interactions. Factors for consideration when choosing an animal model and implant design are discussed. Various bone specific features are discussed including the usage of the species, bone macrostructure and microstructure and bone composition and remodelling, with emphasis being placed on the similarity between the animal model and the human clinical situation. While the rabbit was the most commonly used of the species discussed in this review, it is clear that this species showed the least similarities to human bone. There were only minor differences in bone composition between the various species and humans. The pig demonstrated a good likeness with human bone however difficulties may be encountered in relation to their size and ease of handling. In this respect the dog and sheep/goat show more promise as animal models for the testing of bone implant materials. While no species fulfils all of the requirements of an ideal model, an understanding of the differences in bone architecture and remodelling between the species is likely to assist in the selection of a suitable species for a defined research question.
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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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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.
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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.
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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.
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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.
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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.