Demineralized dentin and enamel matrices as suitable substrates for bone regeneration

Bone regeneration property of tooth-derived bone substitute prepared chairside for periodontal bone defects: an experimental study

BACKGROUND

Periodontitis often leads to progressive destruction and loss of alveolar bone, the reconstruction of which remains difficult in periodontal therapy. As a novel bone graft material, tooth-derived bone substitute (TDBS) processed from extracted teeth has been previously reported about its osteoconductivity and promising results in bone regeneration. This study was to investigate the biological effects and bone regeneration properties of TDBS in vitro and in vivo using rat periodontal bone defect model.

METHODS

Three groups of materials were used in the experiments: TDBS, TDBS treated with ethylene diamine tetraacetic acid (EDTA) (TDBS-E), and allogeneic bone materials. Calcium (Ca) and phosphate (P) ion dissolutions were quantified by spectrophotometer for seven days. The releases of bone morphogenetic protein-2 (BMP-2) and transforming growth factor-β1 (TGF-β1) were identified by enzyme-linked immunosorbent assay (ELISA). Human osteoblast proliferation, migration, and differentiation were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell counting, alkaline phosphatase activity (ALP), and alizarin red staining (ARS), respectively. Furthermore, the osteogenic effects of TDBS on periodontal furcation bone defects were evaluated at eight weeks postoperatively using micro-computed tomography (Micro-CT) and histological analysis.

RESULTS

The dissolution of both Ca and P ions in TDBS increased over time. The BMP-2 released from TDBS was significantly higher than that from TDBS-E and allografts, while the TGF-β1 release from TDBS and TDBS-E groups was higher than that in the allografts. The TDBS-E group could induce the highest level of osteoblast proliferation compared to other groups. Cell migration with allografts co-culture was significantly induced compared to the blank control. However, all groups demonstrated similar positive effects on osteoblast differentiation. Furthermore, in the periodontal model, all materials could effectively enhance bone regeneration in the furcation defect.

CONCLUSIONS

The TDBS prepared chairside as an autogenous bone graft, demonstrating osteoinductivity, which enhances the osteogenic biological characteristics. Therefore, TDBS is suggested as an economical and biocompatible material for periodontal bone regeneration.

The Use of Autogenous Teeth Tissues Grafts for Alveolar Bone Reconstruction: a Systematic Review

Objectives

Enough bone around the implant is an important factor in ensuring the stability and longevity of the implant. Therefore, alveolar bone regeneration procedures are often required. A relatively new bone substitute is made from autogenous teeth. There are more and more studies in the scientific literature that perform regenerative alveolar bone procedures using autogenous tissues substitutes made from extracted teeth. The objective of this systematic literature review is to systematize information and present conclusions about the effectiveness of this regenerative material.

Material and Methods

Scientific articles were selected using the PRISMA recommendations. Publications have been carried out since January 1, 2012 to January 1, 2022. The review includes articles in English, clinical studies in humans who underwent bone augmentation prior to or during dental implantation using an autogenous teeth tissues substitute.

Results

A total of 7 publications were included in this systematic literature review. Summarizing the data of the publications, 258 patients participated in the studies, 240 subjects were included in the results for various reasons, and a total of 298 implants were inserted. No statistically significant results were found in the five studies. Two studies comparing autogenous tooth graft with xenogeneic bone graft and autogenous teeth tissues showed statistically significant positive results in autogenous tooth group.

Conclusions

Within the limitations of this study, autogenous tissues graft derived from teeth are an effective material and can be used as an alternative to other bone grafts existing on the market. Further studies with a longer follow-up period are needed to validate these findings.

Dentin, Dentin Graft, and Bone Graft: Microscopic and Spectroscopic Analysis

BACKGROUND

The use of the human dentin matrix could serve as an alternative to autologous, allogenic, and xenogeneic bone grafts. Since 1967, when the osteoinductive characteristics of autogenous demineralized dentin matrix were revealed, autologous tooth grafts have been advocated. The tooth is very similar to the bone and contains many growth factors. The purpose of the present study is to evaluate the similarities and differences between the three samples (dentin, demineralized dentin, and alveolar cortical bone) with the aim of demonstrating that the demineralized dentin can be considered in regenerative surgery as an alternative to the autologous bone.

METHODS

This in vitro study analyzed the biochemical characterizations of 11 dentin granules (Group A), 11 demineralized using the Tooth Transformer (Group B), and dentin granules and 11 cortical bone granules (Group C) using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to evaluate mineral content. Atomic percentages of C (carbon), O (oxygen), Ca (calcium), and P (phosphorus) were individually analyzed and compared by the statistical t-test.

RESULTS

The significant p-value (p < 0.05) between group A and group C indicated that these two groups were not significantly similar, while the non-significant result (p > 0.05) obtained between group B and group C indicated that these two groups are similar.

CONCLUSIONS

The findings support that the hypothesis that the demineralization process can lead to the dentin being remarkably similar to the natural bone in terms of their surface chemical composition. The demineralized dentin can therefore be considered an alternative to the autologous bone in regenerative surgery.

Comparison of clinical efficacy of three different dentin matrix biomaterials obtained from different devices

AIM

The aim of the present study was to propose the clinical efficacy of the different dentin matrix obtained from three devices (BonMaker, Tooth Transformer, and Smart Dentin Grinder) and to show their morphological, physical, and biochemical characteristics using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and Raman spectroscopy.

RESEARCH DESIGN AND METHODS

The study included 70 patients who underwent bone augmentation using the BonMaker, Tooth Transformer, and Smart Dentin Grinder devices. In addition, 84 implants were placed. Furthermore, four samples, one for each device and one non-demineralized control, were analyzed with scanning electron microscopy (SEM), energy-dispersive X-ray analysis, and Raman spectroscopy.

RESULTS

In all patients, augmentation of bone defects with ground dentin matrix was successful, and implants showed correct osseointegration. The morphological organization, the chemical composition, and the presence of organic molecules in the dentin samples processed by the three different devices were demonstrated using SEM, energy-dispersive X-ray analysis, and Raman spectroscopy.

CONCLUSIONS

Comparing BonMaker, Tooth Transformer, and Smart Dentin Grinder devices in our practice, we concluded that these systems, even with different structural and chemical differences of the dentin granules, have a comparable potential for obtaining regenerative material from the patient's own teeth.

Meta-analysis of application of autogenous dentin for alveolar ridge augmentation

OBJECTIVES

This investigation aimed to systematically evaluate the efficacy and safety of applying autogenous dentin (ATD) in alveolar ridge augmentation.

METHODS

The PubMed, Embase, Web of Science, Cochrane Library, CNKI, and Wanfang databases were electronically searched from January 1, 2010 to March 19, 2022 to identify clinical trials and cohort studies that employed ATD in alveolar ridge augmentation. The Cochrane Tool and the Newcastle-Ottawa Scale were employed to assess the risk of bias in randomized controlled trials and cohort studies, respectively. Data were analyzed via RevMan 5.4 software.

RESULTS

A total of 10 studies were included, 5 of which compared ATD with autologous bone and 5 with deproteinized bovine bone matrix (DBBM). Meta-analysis indicated that ATD had preferable performance [MD=2.01, 95% confidence interval (CI) (1.09, 2.93), P<0.000 1] in horizontal ridge augmentation compared with autologous bone but similar effect in vertical ridge augmentation [MD=-0.06, 95%CI (-0.21, 0.08), P=0.39] at 6 months after alveolar ridge augmentation. In terms of material absorption, ATD was significantly less than autologous bone or DBBM [MD=-0.59, 95%CI (-1.03, -0.15), P=0.008; MD=-0.63, 95%CI (-1.18, -0.07), P=0.03], but no significant difference in implant stability quotient and postoperative complications was observed [MD=-0.76, 95%CI (-3.04, 1.52), P=0.51; RR=1.01, 95%CI (0.33, 3.12), P=0.98].

CONCLUSIONS

ATD, as a bone grafted material for alveolar ridge augmentation, not only achieves similar or better bone incremental performance than autologous bone or DBBM but also has less absorption. However, further evidence from clinical trials with larger samples, higher quality, and longer follow-up period are needed to evaluate its superiority.

Tooth-Derived Granules in Combination with Platelet-Rich Fibrin (“Sticky Tooth”) in Socket Preservation: A Histological Evaluation

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.

Innovative Concepts and Recent Breakthrough for Engineered Graft and Constructs for Bone Regeneration: A Literature Systematic Review

Background: For decades, regenerative medicine and dentistry have been improved with new therapies and innovative clinical protocols. The aim of the present investigation was to evaluate through a critical review the recent innovations in the field of bone regeneration with a focus on the healing potentials and clinical protocols of bone substitutes combined with engineered constructs, growth factors and photobiomodulation applications. Methods: A Boolean systematic search was conducted by PubMed/Medline, PubMed/Central, Web of Science and Google scholar databases according to the PRISMA guidelines. Results: After the initial screening, a total of 304 papers were considered eligible for the qualitative synthesis. The articles included were categorized according to the main topics: alloplastic bone substitutes, autologous teeth derived substitutes, xenografts, platelet-derived concentrates, laser therapy, microbiota and bone metabolism and mesenchymal cells construct. Conclusions: The effectiveness of the present investigation showed that the use of biocompatible and bio-resorbable bone substitutes are related to the high-predictability of the bone regeneration protocols, while the oral microbiota and systemic health of the patient produce a clinical advantage for the long-term success of the regeneration procedures and implant-supported restorations. The use of growth factors is able to reduce the co-morbidity of the regenerative procedure ameliorating the post-operative healing phase. The LLLT is an adjuvant protocol to improve the soft and hard tissues response for bone regeneration treatment protocols.

Evaluation of the Efficacy of Mineralized Dentin Graft in the Treatment of Intraosseous Defects: An Experimental In Vivo Study

Background and Objectives: Dentin grafts have osteoinductive and osteoconductive properties and are considered as an alternative to autogenous graft. This study evaluates the efficacy of autogenous mineralized dentin graft (AMDG) alone or with xenograft and compares it with those of various graft materials used in the treatment of intraosseous bone defects. Materials and Methods: The third incisor teeth of six sheep (2–3 years old) were extracted and AMDG was obtained. Six defects were prepared on each tibia of these six sheep: empty defect (group E); autogenous graft (group A), dentin graft (group D), xenograft (group X), autogenous + xenograft (group A + X) and dentin + xenograft (group D + X). Three sheep in each group were sacrificed in the post-operative 3rd and 6th week and the histologic analyses were performed. Results: The D and D + X groups showed histological features similar to the other groups in the 3rd and 6th weeks. No statistically significant difference was found regarding the rates of new bone formation between the D and D + X groups (p = 1.0) and the other groups at both time intervals (p > 0.05). Conclusions: Similar results observed in this study between groups A, D, X, A + X and D + X demonstrate that AMDG can be successfully used in the treatment of intraosseous bone defects. Further experimental and clinical studies are needed to be able to evaluate the effectiveness of dentin grafts in different types of indications.

Biocompatibility of mesoporous SBA-16/hydroxyapatite nanocomposite and dentin demineralized particles on human dental pulp stem cells

In the present work, a biomaterial (SBA-16/HA) based on the growth of hydroxyapatite (HA) particles within an organized silica structure SBA-16 (Santa Barbara Amorphous-16) was developed to evaluate its application to act as a porous microenvironment promoting attachment and viability of human dental pulp stem cells of healthy deciduous teeth (SHED). First, SHED were isolated and their phenotypes were evaluated by flow cytometry. The samples of SBA-16/HA were characterized by X-ray diffraction (XRD), small and wide angle X-ray scattering (SWAXS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) equipped with energy dispersive spectra detector (EDS). Afterward, cells were cultured in the eluates of the above-mentioned biomaterial aged for 24 hr, 7. and 14 days. Bio-Oss® and dentin particles are involved for comparison and cells are cultured in the eluates of these two materials also. Thiazolyl Blue Tetrazolium bromide assay-MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay) was used for the determination of cell viability. The results obtained by all aforementioned characterization methods of SBA-16/HA, revealed a uniform spherical mesoporous structure, an intrinsic characteristic of this material. This material displayed excellent biocompatibility on SHEDs, and even proliferative potential, indicating that SBA-16/HA could potentially serve as a suitable substrate for bone regeneration. Contrary to SBA-16/HA, dentin particles showed low cytotoxicity at all time points, compared to control and Bio-Oss®groups. Our results substantiate the idea that SBA-16/HA has a beneficial effect on SHEDs, thus paving the way toward developing new material for bone replacement.

Physicochemical and Morphological Characterization of Dentin from Deciduous and Permanent Teeth Processed by Different Methods for Tissue Regeneration

The composition of autogenous dentin differs from that of extracted deciduous and permanent teeth, as graft material must undergo procedures prior to implantation. The aim of this study was to characterize the physicochemical and morphological properties of dentin from deciduous (DTs) and permanent teeth (PTs) that had been demineralized (DMA), deproteinized (DPA), and decellularized (DSA). The dentin particles were DMA with ethylenediaminetetraacetic acid (EDTA), DPA with isopropanol, and DSA with sodium dodecyl sulfate (SDS). Sound dentin (SD) was used as the control group. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) were used to examine the surface and physicochemical properties of the dentin. DMA and DPA dentin had lower concentrations of calcium and protein respectively than SD, showing a significant difference compared with DMA and DPA dentin from DTs and PTs (p < 0.05). In the DSA dentin, it was possible to eliminate the cellular residues of dentin from DTs and PTs, and the gene GAPDH was not expressed. The results of FTIR and XRD revealed a different physicochemical composition according to the dentin processing. EDS demonstrated that DMA dentin obtained the lowest values of calcium and phosphate, and the micrographs obtained by SEM exhibited a porous matrix structure in DMA dentin to a greater degree than in DPA or DSA dentin. The physicochemical properties and morphology of dentin as an autograft material differ depending on whether the teeth are deciduous or permanent; the processing method conditions the characteristics of the dentin substrate as a matrix for tissue regeneration.

Bio-Morphological Reaction of Human Periodontal Ligament Fibroblasts to Different Types of Dentinal Derivates: In Vitro Study

Understanding the biological and morphological reactions of human cells towards different dentinal derivate grafting materials is fundamental for choosing the type of dentin for specific clinical situations. This study aimed to evaluate human periodontal ligament fibroblasts (hPLF) cells exposed to different dentinal derivates particles. The study design included the in vitro evaluation of mineralized dentine (SG), deproteinized and demineralized dentine (DDP), and demineralized dentine (TT) as test materials and of deproteinized bovine bone (BIOS) as the positive control material. The materials were kept with the hPLF cell line, and the evaluations were made after 24 h, 72 h, and 7 days of in vitro culture. The evaluated outcomes were proliferation by using XTT assays, the morphological characteristics by light microscopy (LM) and by the use of scanning electron microscopy (SEM), and adhesion by using confocal microscopy (CLSM). Overall, the experimental materials induced a positive response of the hPLFs in terms of proliferation and adhesion. The XTT assay showed the TT, and the SG induced significant growth compared to the negative control at 7 days follow-up. The morphological data supported the XTT assay: the LM observations showed the presence of densely packed cells with a modified shape; the SEM observations allowed the assessment of how fibroblasts exposed to DDP and TT presented cytoplasmatic extensions; and SG and BIOS also presented the thickening of the cellular membrane. The CLMS observations showed the expression of the proliferative marker, as well as and the expression of cytoskeletal elements involved in the adhesion process. In particular, the vinculin and integrin signals were stronger at 72 h, while the actin signal remained constantly expressed in all the follow-up of the sample exposed to SG material. The integrin signal was stronger at 72 h, and the vinculin and actin signals were stronger at 7 days follow-up in the sample exposed to DDP material. The vinculin and integrin signals were stronger at 72 h follow-up in the sample exposed to TT material; vinculin and integrin signals appear stronger at 24 h follow-up in the sample exposed to BIOS material. These data confirmed how dentinal derivates present satisfying biocompatibility and high conductivity and inductivity properties fundamental in the regenerative processes. Furthermore, the knowledge of the effects of the dentin’s degree of mineralization on cellular behavior will help clinicians choose the type of dentine derivates material according to the required clinical situation.

Retrospective Study on Tooth Shell Technique Using Endodontically Treated Teeth in Lateral Ridge Augmentation

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.

Retrospective Study: Lateral Ridge Augmentation Using Autogenous Dentin: Tooth-Shell Technique vs. Bone-Shell Technique

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.

Autologous Materials in Regenerative Dentistry: Harvested Bone, Platelet Concentrates and Dentin Derivates

The jawbone is a peculiar type of bone tissue, unique for its histological, anatomical and physiological characteristics. Therefore, a defect in the maxilla or in the mandible, because of pathological sequelae is difficult to prevent and to restore. Several biomaterials have been and are currently being developed to respond to the demands of regenerative medicine. A specific group of biomaterials used in regenerative dentistry is represented by the autologous materials. Platelet concentrates harvested bone and dentin derivates are indeed used in an attempt to minimise the alveolar resorption or in vertical ridge augmentation procedures or in sinus lift interventions. The aim of this review is to examine the properties of the above-listed materials, to compare them and to indicate eventual clinical applications.

Alveolar Socket Preservation with Different Autologous Graft Materials: Preliminary Results of a Multicenter Pilot Study in Human

BACKGROUND

The histological and histomorphometrical results were evaluated between vital whole and non-vital endodontically treated teeth used as autologous grafts in post-extractive socket preservation procedures.

METHODS

Twenty-eight patients (average age 51.79 ± 5.97 years) with post-extractive defects were enrolled in five dentistry centers. All patients were divided into two groups: with whole teeth (Group 1) and teeth with endodontical root canal therapy (Group 2). The extracted teeth were processed with the Tooth Transformer device to obtain a demineralized and granulated graft material used with a resorbable collagen membrane for socket preservation. After four months, 32 bone biopsies were obtained for histological, histomorphometric, and statistical analysis.

RESULTS

During the bone healing period, no infection signs were observed. Nineteen biopsies in group 1 and 13 biopsies in group 2 were detected. The histological analysis showed neither inflammatory nor infective reaction in both groups. Autologous grafts surrounded by new bone were observed in all samples and, at high magnification, partially resorbed dentin and enamel structures were detected. No gutta-percha or cement was identified. Small non-statistically significant differences between the groups, in total bone volume (BV), autologous graft residual, and vital bone percentage were detected.

CONCLUSIONS

The study showed that the TT Transformer grafts were capable of producing new vital bone in socket preservation procedures. The histomorphometric results showed no statistical differences comparing whole and endodontically treated teeth in bone regeneration. Further studies will be carried out in order to understand the advantages of the autologous graft materials obtained from the tooth compared with the current biomaterials in bone regeneration treatments.

Tissue engineering in periodontology: Biological mediators for periodontal regeneration

Teeth and the periodontal tissues represent a highly specialized functional system. When periodontal disease occurs, the periodontal complex, composed by alveolar bone, root cementum, periodontal ligament, and gingiva, can be lost. Periodontal regenerative medicine aims at recovering damaged periodontal tissues and their functions by different means, including the interaction of bioactive molecules, cells, and scaffolds. The application of growth factors, in particular, into periodontal defects has shown encouraging effects, driving the wound healing toward the full, multi-tissue periodontal regeneration, in a precise temporal and spatial order. The aim of the present comprehensive review is to update the state of the art concerning tissue engineering in periodontology, focusing on biological mediators and gene therapy.

A New Tooth Processing Apparatus Allowing to Obtain Dentin Grafts for Bone Augmentation: The Tooth Transformer

Introduction:

Human dentin matrix could be considered an excellent alternative to autologous or heterologous bone graft. Autologous tooth graft has been proposed since 1967 when the osteoinduction properties of autogenous demineralized dentin matrix were discovered.

Methods:

The preparation technique to transform autologous teeth in suitable grafting material still represents the fundamental step of the whole procedure.

Aim:

The aim of the present study was to test an innovative medical device that could obtain tooth graft materials starting from the whole tooth of the patient. 15 consecutive cases of tooth grafting procedures were performed with a mean follow up period of 18 months.

Results:

In all cases, after 6 months of healing, the defects were almost completely filled by newly formed hard tissue. The new tissue was examined after 6 months, both from a radiological point of view by CBCT scans and from a clinical observation. It showed a compactness similar to the medium-density bone. No signs of inflammations were observed. No infective complications were recorded during the post-operative healing. No graft particles or grains were visible in the regenerated bone structure that appeared homogeneous and uniform.

Discussion:

The results of the present study showed favorable bony healing in guided regenerative surgery procedures using autologous tooth graft. Future studies with long follow up period are needed in order to better evaluate the potential of demineralized dentin autografts.

BMP-2 and type I collagen preservation in human deciduous teeth after demineralization

BACKGROUND

Great interest has recently been focused on tooth and tooth derivatives as suitable substrates for the treatment of alveolar bone defects. Here, we propose the use of demineralized baby teeth (BT) as potential grafting materials for bone augmentation procedures.

METHODS

Particles of human BT (Ø < 1 mm) were demineralized by means of a chemical/thermal treatment. Demineralized BT particles were thoroughly characterized by scanning electron microscopy/energy dispersive X-ray analyses to evaluate the effects of the demineralization on BT topography and mineral phase composition, and by enzyme-linked immunosorbent assays (ELISA) to quantify collagen and bone morphogenetic protein-2 (BMP-2) protein contents. The response of SAOS-2 cells to exogenous BMP-2 stimulation was evaluated to identify the minimum BMP-2 concentration able to induce osteodifferentiation in vitro (alkaline phosphatase (ALP) activity).

RESULTS

The demineralization treatment led to a dramatic decrease in relative Ca and P content (%) of ≈75% with respect to the native BT particles, while preserving native protein conformation and activity. Interestingly, the demineralization process led to a rise in the bioavailability of BMP-2 in BT particles, as compared to the untreated counterparts. The BMP-2 content found in demineralized BT was also proved to be very effective in enhancing ALP activity, thus in the osteodifferentiation of SAOS-2 cells in vitro, as confirmed by cell experiments performed upon exogenously added BMP-2.

CONCLUSIONS

In this study we demonstrate that the BMP-2 content found in demineralized BT is very effective in inducing cell osteodifferentiation, and strengthens the idea that BTs are very attractive bioactive materials for bone-grafting procedures.