Autologous Tooth Dentin Graft: A Retrospective Study in Humans

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Advances in autogenous dentin matrix graft as a promising biomaterial for guided bone regeneration in maxillofacial region: A review

Autogenous dentin matrix (ADM), derived from a patient's extracted tooth, can be repurposed as an autologous grafting material in reconstructive dentistry. Extracted teeth provide a source for ADM, which distinguishes itself with its low rejection rate, osteoinductive capabilities and ease of preparation. Consequently, it presents a viable alternative to autogenous bone. Animal studies have substantiated its effective osteoinductive properties, while its clinical applications encompass post-extraction site preservation, maxillary sinus floor augmentation, and guided bone tissue regeneration. Nevertheless, the long-term efficacy of ADM applied in bone regeneration remains underexplored and there is a lack of standardization in the preparation processes. This paper comprehensively explores the composition, mechanisms underlying osteoinductivity, preparation methods, and clinical applications of ADM with the aim of establishing a fundamental reference for future studies on this subject.

Comparison of clinical efficacy between autologous partially demineralized dentin matrix and deproteinized bovine bone mineral for bone augmentation in orthodontic patients with alveolar bone deficiency: a randomized controlled clinical trial

BACKGROUND

It is common to see patients who need orthodontic treatment but with insufficient alveolar bone volume. However, safe and effective tooth movement requires sufficient alveolar bone width and height. The aim of this study is to compare the bone augmentation efficacy of Autologous Partially Demineralized Dentin Matrix (APDDM) and Deproteinized Bovine Bone Mineral (DBBM) in orthodontic patients with insufficient bone by using a randomized controlled clinical trial approach.

MATERIALS AND METHODS

Twenty-seven orthodontic patients involving 40 posterior teeth alveolar sites (n = 40) with insufficient alveolar bone volume were randomly divided into a control group (n = 20) and an experimental group (n = 20). The patients in the experimental group were treated with APDDM, and those in the control group were treated with DBBM. After surgery, the adjacent teeth are moved toward the bone grafting sites according to the orthodontic treatment plan. Patients completed a postoperative response questionnaire by the Visual Analogue Scale (VAS) score to indicate pain and swelling in the bone grafted area at the time of suture removal; and CBCT scans were conducted before surgery, 6 months and 2 years after surgery to assess changes in buccal and central alveolar heights, as well as widths at the alveolar ridge apex and 3 mm, 5 mm below the apex, respectively. The CBCT image sequences were imported into Mimics 21.0 software in DICOM format. The data of the patients in both groups were collected and analyzed by SPSS 25.0.

RESULTS

The VAS scores were significantly lower in the APDDM group than in the DBBM group (p < 0.05). Significant increases were observed in alveolar bone height and width at 6 months and 2 years postoperative (p < 0.05); At 2 years, the APDDM group exhibited a reduction in buccal crest height and in 3 mm, 5 mm width below alveolar ridge apex, relative to 6 months (p < 0.05), while the DBBM group showed a decrease only in the central height of the alveolar bone (p < 0.05). There was a significant bone augmentation increase found only 3 mm below the alveolar ridge apex in the APDDM group compared with the DBBM group among all 6 months group comparison (p < 0.05). At 2 years, the augmentation effects were similar across both groups (p > 0.05).

CONCLUSION

Radiomics analysis indicates that APDDM serves as a viable bone augmentation material for orthodontic patients with insufficient alveolar bone volume, achieving comparable clinical efficacy to DBBM. Additionally, APDDM is associated with a milder postoperative response than DBBM.

THE REGISTRATION NUMBER (TRN)

ChiCTR2400084607.

Evaluation and comparison of autologous particulate dentin with demineralized freeze dried bone allograft in ridge preservation procedures - a prospective clinical study

OBJECTIVES

To compare effectiveness of Autologous Particulate Dentin (APD) with Demineralized Freeze-Dried Bone Allograft (DFDBA) in ridge preservation, using radiographic and clinical parameters.

MATERIALS AND METHODS

Thirty subjects with indication of mandibular posterior teeth extraction were randomly assigned to either test or control group. After atraumatic extraction, ridge preservation was performed using APD or DFDBA mixed with i-PRF in test and control groups respectively. Both groups had sockets sealed with A-PRF membrane. Clinical parameters (plaque, gingival and healing indices) and radiographic parameters (vertical ridge height, horizontal ridge width) were assessed at baseline and 6 months using CBCT. Statistical analysis was performed using an independent t-test to compare clinical and radiographic parameters between the groups.

RESULTS

Both groups had significant decreases in ridge dimensions over 6 months (p < 0.001). The test group showed less reduction in ridge dimensions than control group at 6 months (p < 0.001). Mean change in vertical height was not significant (1.37 ± 1.32, 1.7311 ± 0.563), but in horizontal ridge width (1.3120 ± 1.13, 1.8093 ± 1.16) was significantly different between test and control groups respectively. There was no statistical difference in clinical parameters between the groups at 6 months (p > 0.001).

CONCLUSIONS

APD grafts resulted in significant improvements in radiographic parameters, specifically in vertical ridge height and horizontal ridge width, compared to DFDBA group.

CLINICAL RELEVANCE

Autologous particulate dentin is a promising, versatile substitute for regenerative procedures. While more research on its long-term efficacy and application is needed, current evidence suggests it could significantly improve patient care and outcomes.

How effective is dentin autograft for socket preservation and implant site preparation: A systematic review protocol

Background

Socket preservation is a surgical procedure aimed at preserving the dimensions of the alveolar bone following tooth extraction. It is performed by filling the extraction socket with bone graft material with or without a barrier membrane. Recently, dentine obtained from extracted teeth has been tried as an autograft for socket preservation. Studies have compared the use of dentin to other bone grafts, however, systematic reviews evaluating the efficacy of dentin for socket preservation are limited. Hence, this systematic review protocol is proposed to generate evidence on the efficacy of dentin as a viable alternative to other bone graft materials for socket preservation.

Methods

This systematic review protocol was prepared according to the Methodological Expectations of the Cochrane Intervention Reviews (MECIR) guidelines. It will be conducted using the Cochrane Handbook for Systematic Review of Interventions. PubMed, Scopus, Web of Science, EMBASE, Epistemonikos, Cochrane Central, and EBSCO databases and clinical trial registries, will be searched for all randomized controlled trials (RCTs) and non-randomized studies that have used autologous dentin graft (either in particulate/putty, or/matrix form) for socket preservation. The radiographic and clinical assessment of bone and soft tissue healing of the preserved sockets along with patient-related outcomes following surgery will be assessed. The risk of bias assessment of the RCTs and Non-RCTs will be assessed using the 'Cochrane Risk of Bias assessment tool (ROB II) and ROBINS-I respectively. The certainty of evidence will be assessed by the GRADE approach.

Discussion

This evidence is important for dental clinicians and the public to make an informed decision when choosing graft material for socket preservation. The extracted teeth are considered biological waste; however, this evidence provides scope for using a less invasive autograft for bone regenerative procedures.

Systematic review registration

PROSPERO: CRD42021201958 (Registered on 15/02/2021).

Use of autologous tooth-derived material as a graft in the post-extraction socket. Split-mouth study with radiological and histological analysis

BACKGROUND

The healing process after tooth removal involves bone remodelling which implies some loss of alveolar bone volume. Among materials proposed for minimising this remodelling and preserving the bone, autologous dental tissue is a promising option, but more data are needed. In this context, we evaluated size and density changes using cone beam computed tomography in autologous dental material (ADM)-preserved sockets compared to controls, and assessed biological responses by histological analysis.

METHODS

A split-mouth study was conducted including 22 patients, who underwent removal of ≥ 2 single-rooted teeth with intact sockets, assigning one socket to the experimental group which received ADM for alveolar preservation and another to the control group, which only underwent blood clot stabilisation. Cone beam computed tomography was performed postoperatively (week 0) and at weeks 8 and 16 to assess socket size and bone density. Histological analysis was carried out on trephine biopsies taken (Ø4 × 4.5 mm) from the experimental group.

RESULTS

Less horizontal shrinkage was observed in the ADM group, especially at week 16 considering the group-by-time interaction for the following variables: difference in height between the lingual and buccal alveolar crests (-1.00; p < .01; 95% CI: -0.28 - -1.73), and half-widths, measured as the distance from the long axis of the missing tooth to the buccal alveolar crest at 1 mm (-0.61; p < .01; 95% CI: -0.18 - -1.04) and at 3 mm (-0.56; p < .01; 95% CI: -0.15 - -0.97) below the crest, with mean decreases of 1.07 and 2.14 mm in height difference, 0.66 and 1.32 mm in half-width at 1 mm and 0.43 and 1.02 mm in half-width at 3 mm in ADM and control groups respectively. Densitometry analysis showed higher bone densities in Hounsfield units in the ADM group considering all factors analysed regardless of time point and socket third (coronal, middle, or apical). Histologically, there were no signs of inflammation or foreign body reaction, and dentin particles were surrounded by and in close contact with bone tissue.

CONCLUSION

These results add to the evidence that dentin can be used successfully as a material for alveolar socket preservation, given its desirable mechanical and biological properties, and warrant larger studies.

Osteoinductive Properties of Autologous Dentin: An Ex Vivo Study on Extracted Teeth

Over the last decades, a variety of biomaterials, ranging from synthetic products to autologous and heterologous grafts, have been recommended to conserve and regenerate bone tissue after tooth extraction. We conducted a biochemical study on ground extracted teeth that aimed to evaluate the osteoinductive and osteoconductive potential of dentin by assessing the releases of bone morphogenetic protein (BMP-2), osteocalcin (OC) and osteonectin (ON) over time (24 h, 10 days and 28 days). Twenty-six patients, who required the extraction of nonrestorable teeth, were enrolled in the study according to the inclusion criteria, as follows: thirteen young patients 18 to 49 years of age (UNDER 50), and thirteen patients of 50 to 70 years (OVER 50); a total of twenty-six teeth were extracted, ground and analyzed by enzyme-linked immunosorbent assays (ELISA). All ground teeth released BMP-2, OC and ON at each time point; no differences were observed between the UNDER-50 and OVER-50 patients. The results of the study support the use of autologous dentin as osteoinductive material for bone regeneration procedures, irrespective of patients' ages.

Alveolar ridge preservation in sockets with severe periodontal destruction using autogenous partially demineralized dentin matrix: A randomized controlled clinical trial

BACKGROUND

The preservation and reconstruction of alveolar ridge volume in extraction sockets of molars affected by severe periodontitis is a critical challenge that requires clinical attention.

PURPOSE

This randomized controlled clinical trial was designed to evaluate the efficiency of autogenous partially demineralized dentin matrix (APDDM) for alveolar ridge preservation (ARP) in severely periodontally compromised sockets compared to spontaneous healing (SH) on radiographic and histomorphometric outcomes.

MATERIALS AND METHODS

Thirty-two patients with 32 periodontally compromised molars were randomized into either the test group, which received ARP using APDDM covered with a collagen sponge, or the control group, which underwent SH. Linear and volumetric changes were assessed using superimposed cone-beam computed tomography (CBCT) acquired pre-extraction and after a 4-month healing time. Histomorphometric evaluation was performed on trephine cores harvested during implant placement.

RESULTS

All sites healed uneventfully. The ridge width at 1 mm apical to the bone crest increased by 5.03, 4.50, and 5.20 mm in the mesial, middle, distal area in the APDDM group, while decreasing by -1.98, -2.19, and -1.98 mm in the SH group, respectively (p < 0.05). The height increase of the central bone was significantly higher in the APDDM group than in the SH group (p < 0.05). The height decrease of the buccal (mesial, middle, distal) bone plate was lower in the APDDM group than in the SH group (p < 0.05). After a 4-month healing time, bone volume increased by 37.07% in the APDDM group and by only 2.33% in the SH group (p < 0.05). Histomorphometric analysis revealed that APDDM particles were surrounded by newly formed bone, with partially absorbed residual APDDM materials observed. New bone, APDDM remnants, and connective tissue occupied 39.67 ± 8.28%, 23.66 ± 9.22%, and 36.67 ± 17.05% of the areas in the APDDM group, respectively.

CONCLUSIONS

ARP using APDDM was effective, resulting in a significant increase in both linear and volumetric changes in severely periodontally compromised extraction sockets compared to SH. These findings suggest that APDDM may serve as a promising new clinical option for the reconstruction of alveolar ridge dimensions.

Auto-dentin platelet-rich fibrin matrix is an alternative biomaterial for different augmentation procedures: A retrospective case series report

OBJECTIVES

Autologous dentin grafts derived from extracted teeth have shown promise as bone graft materials for promoting bone regeneration. This retrospective case series aimed to evaluate clinical, radiographic, and histologic outcomes of using autologous dentin matrices in various bone regeneration procedures.

MATERIALS AND METHODS

This case series included 26 eligible patients and encompassed 4 socket preservation cases, 5 cases of guided tissue regeneration, 5 cases of guided bone regeneration (GBR), 10 cases of sinus augmentation procedures, 2 immediate placement implants, and 2 socket shields. Dentin grafts were prepared from extracted teeth, cleaned, and processed. These grafts were combined with platelet-rich fibrin (PRF) to create adhesive dentin matrices, then covered with collagen membranes for simultaneous guided bone augmentation cases. Cone beam computed tomography (CBCT) scans were conducted before surgery and 4 months postoperatively to assess ridge dimensions. Histologic evaluation was performed through bone core biopsies for socket preservation cases at the 4-month mark.

RESULTS

A total of 42 implants were placed in 26 patients, with an average follow-up of 32 months. Notably, two implant failures occurred following lateral maxillary sinus augmentation. CBCT scans at the 4-month interval revealed bone coverage over implant platforms in the majority of cases. Histologic analysis from two cases of socket preservation demonstrated dentin granules enveloped by newly formed bone undergoing continuous remodeling. The quantitative histomorphometric assessment revealed a bone area of 42.8 ± 3.56%, a remaining graft area of 19.05 ± 4.58%, and a viable bone of 38.15 ± 7.84%.

CONCLUSIONS

The utilization of autologous dentin particles mixed with PRF proved effective as an alternative to conventional bone graft materials in GBR and maxillary sinus augmentation procedures. Larger controlled clinical trials are recommended to further substantiate these findings.

Histological examination of tooth-derived biomaterials obtained from different devices

AIM

The aim of the present study was to investigate the histological differences between samples processed by different devices and to confirm safe clinical application of different dentin matrix obtained from three devices: BonMaker, Tooth Transformer, and Smart Dentin Grinder in regeneration of maxillary defects.

RESEARCH DESIGN

The study involved 39 patients with two-wall or three-wall defects who underwent bone augmentation procedures in the maxilla using dentin matrix grafts from the BonMaker, Tooth Transformer, and Smart Dentin Grinder devices. Histological examination was conducted on samples obtained from patients who received each device. In this article, histological samples have been selected and are presented.

RESULTS

In all patients, bone defects were successfully augmented with ground dentin matrix. The histological examination revealed no inflammation and a good connection between the bone and dentin matrix and clinically all patients were qualified for implant placement.

CONCLUSIONS

After comparing the BonMaker, Tooth Transformer, and Smart Dentin Grinder devices in our practice, we concluded that all these systems have the potential for obtaining regenerative material from the patient's teeth.

A novel porcine dentin-derived bone graft material provides effective site stability for implant placement after tooth extraction: a randomized controlled clinical trial

OBJECTIVES

Assessment of the clinical performance of a porcine dentin-derived particulate bone graft material for bone regeneration after tooth extraction with implant placement at 4 months, in comparison to a commercially available porcine bone-derived graft.

MATERIAL AND METHODS

This study was a randomized, parallel-group, semi-double-blinded clinical trial evaluating the clinical safety, tolerability, and performance of Ivory Dentin Graft™ in comparison with a commercial bone-derived material in alveolar ridge preservation following tooth extraction (registered at ClinicalTrials.gov, May 12th, 2017, Identifier NCT03150472). Extraction sites were grafted with test or comparator material and a titanium implant placed at 4 months after taking a graft site biopsy. Primary endpoints were the extent of new bone growth and bone-graft integration at 4 months.

RESULTS

The dentin graft material had statistically significantly more new bone formation (60.75% vs 42.81%, p = 0.0084, N = 20 vs 16), better bone-graft integration scores (good integration in 85% vs 40%, p = 0.0066), and higher mean radiodensity of the bone (981.5HU vs 727.7HU, p = 0.0011) at the graft site compared to the bone-derived material. The mean implant insertion torque force was similar for the dentin and bone materials (34.75 Ncm vs 34.06 Ncm). Titanium implant placement was successful in 95% of patients with the dentin graft material compared to 81.25% for the bone graft. Both materials had similar clinical safety and tolerability as determined by adverse events and local site reactions. Physician-assessed ease of grafting and ease of implant placement on a 10-point scale showed no statistical differences (8.78 vs 8.27, p = 0.2355; 8.05 vs 8.75, p = 0.1118, respectively).

CONCLUSIONS

A porcine dentin-derived bone graft material has clinical safety, tolerability, and performance for implant placement at 4 months after tooth extraction at least as good as a commercial bone-derived material.

CLINICAL RELEVANCE

The availability of porcine dentin-derived bone graft material allows wider use of dentin-derived material which has so far only been available in the form of autologous dentin from the patient's own teeth.

The Use of Human Sterilized Crushed Tooth Particles Compared with BTCP Biomaterial and Empty Defects in Bone Formation inside Critical Rabbit Calvaria Sites

This study aimed to assess the bone regeneration of critical-size defects in rabbit calvaria filled with freshly crushed extracted teeth, comparing them with BTCP biomaterial and empty sites. Materials and methods: Twenty-one female New Zealand rabbits were used in this study. Two critical-size defects 6 mm in size were created in the skull bone, each with a 3 mm separation between them. Three experimental groups were evaluated: Group A (human sterilized crushed teeth granules alone), Group B (Bioner Bone, Bioner Sitemas Implantológicos), and Group C (unfilled defects). The animals were sacrificed at 4 and 8 weeks. Evaluation of the samples involved histological and histomorphometric analyses with radiographic evaluation. The histological evaluation showed a higher volume reduction in Group A compared with Group B (p < 0.05) and Control. Group A showed the highest values for cortical closure and bone formation around the particles, followed by Group B and Group C (p < 0.05). Within the limitations of this animal study, we can conclude that the use of human tooth particles leads to increased bone formation and reduced connective tissue in critical-size defects in rabbit calvaria when compared to BTCP biomaterial. The calvarial model is a robust base for the evaluation of different biomaterials.

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.

Autologous Tooth Graft: Innovative Biomaterial for Bone Regeneration. Tooth Transformer® and the Role of Microbiota in Regenerative Dentistry. A Systematic Review

Different biomaterials, from synthetic products to autologous or heterologous grafts, have been suggested for the preservation and regeneration of bone. The aim of this study is to evaluate the effectiveness of autologous tooth as a grafting material and examine the properties of this material and its interactions with bone metabolism. PubMed, Scopus, Cochrane Library, and Web of Science were searched to find articles addressing our topic published from 1 January 2012 up to 22 November 2022, and a total of 1516 studies were identified. Eighteen papers in all were considered in this review for qualitative analysis. Demineralized dentin can be used as a graft material, since it shows high cell compatibility and promotes rapid bone regeneration by striking an ideal balance between bone resorption and production; it also has several benefits, such as quick recovery times, high-quality newly formed bone, low costs, no risk of disease transmission, the ability to be performed as an outpatient procedure, and no donor-related postoperative complications. Demineralization is a crucial step in the tooth treatment process, which includes cleaning, grinding, and demineralization. Since the presence of hydroxyapatite crystals prevents the release of growth factors, demineralization is essential for effective regenerative surgery. Even though the relationship between the bone system and dysbiosis has not yet been fully explored, this study highlights an association between bone and gut microbes. The creation of additional scientific studies to build upon and enhance the findings of this study should be a future objective of scientific research.

Collagen-chitosan-hydroxyapatite composite scaffolds for bone repair in ovariectomized rats

Lesions with bone loss may require autologous grafts, which are considered the gold standard; however, natural or synthetic biomaterials are alternatives that can be used in clinical situations that require support for bone neoformation. Collagen and hydroxyapatite have been used for bone repair based on the concept of biomimetics, which can be combined with chitosan, forming a scaffold for cell adhesion and growth. However, osteoporosis caused by gonadal hormone deficiency can thus compromise the expected results of the osseointegration of scaffolds. The aim of this study was to investigate the osteoregenerative capacity of collagen (Co)/chitosan (Ch)/hydroxyapatite (Ha) scaffolds in rats with hormone deficiency caused by experimental bilateral ovariectomy. Forty-two rats were divided into non-ovariectomized (NO) and ovariectomized (O) groups, divided into three subgroups: control (empty defect) and two subgroups receiving collagen/chitosan/hydroxyapatite scaffolds prepared using different methods of hydroxyapatite incorporation, in situ (CoChHa1) and ex situ (CoChHa2). The defect areas were submitted to macroscopic, radiological, and histomorphometric analysis. No inflammatory processes were found in the tibial defect area that would indicate immune rejection of the scaffolds, thus confirming the biocompatibility of the biomaterials. Bone formation starting from the margins of the bone defect were observed in all rats, with a greater volume in the NO groups, particularly the group receiving CoChHa2. Less bone formation was found in the O subgroups when compared to the NO. In conclusion, collagen/chitosan/hydroxyapatite scaffolds stimulate bone growth in vivo but abnormal conditions of bone fragility caused by gonadal hormone deficiency may have delayed the bone repair process.

Autogenous dentin combined with mesenchymal stromal cells as an alternative alveolar bone graft: an in vivo study

OBJECTIVE

Considering the chemical and structural properties of dentin, this study was aimed at evaluating the effect of dentin matrix alone or combined with mesenchymal stromal cells (MSC) on postextraction alveolar bone regeneration.

MATERIAL AND METHODS

Wistar rats were subjected to tooth extraction with osteotomy and allocated into groups according to the graft inserted: (1) Gelita-Spon^®, (2) Bio-Oss^®, (3) Dentin, (4) MSC, (5) Dentin/MSC, and (6) Control. Maxillae were analyzed by means of hematoxylin and eosin (H&E) staining, immunohistochemical (IHC) analysis, microcomputed tomography (micro-CT), and scanning electron microscopy (SEM). Serum levels of calcium and phosphorus were quantified.

RESULTS

The Bio-Oss group showed less bone than Gelita-Spon and Dentin/MSC; no other significant differences were seen in H&E analysis. The Bio-Oss group showed higher expression of collagen type I compared to the Dentin and Dentin/MSC groups and also higher osteocalcin expression than the Dentin/MSC group. There was a tendency of higher expression of osteopontin in the MSC, Dentin, and Dentin/MSC groups and higher VEGF in the MSC group. On micro-CT analysis, the Bio-Oss and the Dentin/MSC groups exhibited greater bone volume than the Control. Serum calcium and phosphorus levels did not significantly differ between the groups. SEM analysis depicted particles of Bio-Oss and dentin in the respective groups, as well as significant cellularity in the MSC group.

CONCLUSION

Autogenous nondemineralized dentin is an alternative for alveolar bone grafting, which can be improved by combination with MSC.

CLINICAL RELEVANCE

This work provides support for the clinical applicability of dentin graft alone or combined with MSC.

Investigation of Different Types of Micro- and Nanostructured Materials for Bone Grafting Application

The insufficient volume of dental ridges is one of the most severe problems regarding an oral cavity. An inadequate amount can cause problems during various types of dental treatment. Its complexity originates from the etiopathogenesis of this problem. In this study, the representatives of auto-, allo-, and xenografts are compared. The physic-chemical differences between each of them were evaluated using XRD (X-ray Powder Diffraction), a SEM (Scanning Electron Microscopy), FT-IR (Fourier transformed infrared spectroscopy), and TGA (thermogravimetric analysis). Based on the SEM images, it was observed that the origin of the material has an influence on collagen fiber compact level and porosity. Following a comparison of FT-IR spectra and XRD, the crystal and chemical structures were described. Based on TGA, different water concentrations of the investigated materials, their high thermal stability, and concentration of inorganic phase, hydroxyapatite was determined. The presented study is important because it delivers information about chemical structure and its impact on bone regeneration. This knowledge should be taken into consideration by dental clinicians, because different types of bone grafts can accommodate the achievement of various goals.