Comparative Histomorphometric Analysis of Maxillary Sinus Augmentation With Deproteinized Bovine Bone and Demineralized Particulate Human Tooth Graft: An Experimental Study in Rabbits

Optimizing Bone Regeneration with Demineralized Dentin-Derived Graft Material: Impact of Demineralization Duration in a Rabbit Calvaria Model

This study evaluated the regenerative potential of demineralized dentin-derived matrix (DDM) as a bone graft material in rabbit calvaria. DDM, sourced from extracted teeth, is emerging as an alternative to traditional grafts like allografts and xenografts. We aimed to identify the most effective demineralization protocol to optimize the regenerative capacity of DDM. Four groups were compared: a control group without grafts, a non-demineralized DDM group, and two demineralized DDM groups (15 and 30 min demineralization). Histomorphometric analysis was conducted in a randomized and blinded setting at 2, 4, and 8 weeks post-graft placement. The results revealed that the 15 min demineralized DDM group showed the most significant new bone formation (42.51% ± 6.40% at 8 weeks; p < 0.05), suggesting its potential as a highly effective regenerative graft material.

Maxillary Sinus Augmentation with Autogenous Tooth Grafting Material: A Systematic Review

The aim of this systematic review was to determine whether autogenous tooth grafting material (ATGM) is as safe and effective as other bone substitutes used for maxillary sinus augmentation procedures, evaluating histomorphometric and/or histological data, implant primary stability, associated complications and radiographic bone height measurements. An automated electronic search was conducted using four databases (Medline/PubMed, Scopus, Web of Science and Cochrane Library), supplemented by a manual search, to identify clinical human studies using particulate ATGM for the aforementioned procedure. The included studies had a sample size of at least four patients and were published before 31st July 2024. The Newcastle-Ottawa scale (NOS) and Joanna Briggs Institute (JBI) Critical Appraisal Checklist were used to assess the risk of bias in cohort studies and case series, respectively. Seven studies were included in the descriptive analysis, obtaining 128 participants (46.8% only treated with ATGM) and 192 placed implants. Due to the heterogeneity of the studies, meta-analysis could not be performed. The authors concluded that ATGM appears to be a feasible and safe alternative for maxillary sinus augmentation procedures. These results should be interpreted with caution due to the limited amount of scientific evidence on this topic and the heterogeneity between the included studies.

Tooth Graft: An Umbrella Overview

This umbrella review aims to evaluate systematic/meta-analysis studies containing clinical evidence on tooth grafts as bone substitutes in the oral and maxillofacial regions. Using language restrictions and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, an electronic database search of PubMed, MEDLINE, Embase, Cochrane library, and Google Scholar was conducted, featuring published studies up until August 2022. All systematic/meta-analysis review articles relating to tooth graft materials were matched against the inclusion criteria. Two qualified researchers independently assessed the studies' inclusion or exclusion criteria and risk of bias, and a third investigator assisted in resolving ambiguities. A total of 81 systematic/meta-analysis studies, comprising 21 animal-controlled trials, 23 randomized controlled human trials, 23 prospective studies, and 14 retrospective studies, were selected for this study. A small risk of bias was observed in systematic studies/meta-analyses. In addition, the clinical evidence from the analysis of these studies revealed a low incidence of side effects. According to the current review, two systematic reviews indicated that autogenous bone grafting of prepared teeth might be as effective as other bone grafting materials. Four studies also mentioned autologous grafts as potential alternatives to autologous grafts, autogenous demineralized dentin (ADDM), engineered grafts, root blocks, and dental matrix. On the other hand, three systematic studies stated that more long-term research is needed to confirm their findings. Finally, given the importance of standardization and homogeneity of studies for clinical cases, it is advised to be used cautiously due to the risks of transplant rejection.

Early tissue and healing responses after maxillary sinus augmentation using horizontal platelet rich fibrin bone blocks

BACKGROUND

The effects of horizontal platelet-rich fibrin (H-PRF) bone block on the healing and immune response during sinus augmentation have not been fully investigated histologically at early time points.

METHODS

Eighteenth male New Zealand white rabbits underwent bilateral sinus augmentation and were divided into two groups: deproteinized bovine bone mineral (DBBM) alone and H-PRF + DBBM (H-PRF bone block) group. Maxilla samples were collected at 3, 7 and 14 days post sinus augmentation procedures and analyzed using histological staining for the number of inflammatory cells, new blood vessels and evidence for early osteoclast bone turnover/remodeling. Furthermore, the effects of H-PRF bone blocks on the migration of osteoblasts and THP-1 macrophages were evaluated using a Transwell assay in vitro.

RESULTS

A higher number of immune cells were found in the H-PRF bone block group at 3 and 7 days post-surgery when compared to the DBBM alone group,most notably in the regions close to the mucosal lining and bone plates. Furthermore, a significantly greater number of new blood vessel formations and early signs of osteoclast development were found in the H-PRF bone block group at 14 days. The in vitro transwell assay further confirmed that culture medium from H-PRF bone block markedly promote the migration of osteoblasts and THP-1 macrophages.

CONCLUSIONS

The findings from this study have shown that H-PRF bone block is capable of increasing early immune cell infiltration leading to the acceleration of neovascularization and speeding the process of bone metabolism in vivo following maxillary sinus grafting with DBBM.

Radiological and Histological Analyses of Nonrigid Versus Rigid Fixation for Free Bone Block Procedures in a Rabbit Model of Glenoid Defects

BACKGROUND

Nonrigid fixation techniques have been recently introduced in free bone block (FBB) procedures to treat substantial glenoid bone loss in patients with anterior shoulder instability. However, the radiological and histological effectiveness of nonrigid fixation versus conventional rigid fixation have not been comprehensively understood in vivo.

PURPOSE

To (1) explore the radiological and histological characteristics of nonrigid fixation for FBB procedures in a rabbit model of glenoid defects and (2) further compare them with those of conventional rigid fixation.

STUDY DESIGN

Controlled laboratory study.

METHODS

Unilateral shoulder glenoid defects were created in 36 mature New Zealand White rabbits, of which 24 underwent FBB procedures using allogenic iliac crest bone and were randomly divided into rigid fixation (RF) and nonrigid fixation (N-RF) groups, with the remaining divided into 2 control groups: 6 with sham surgery for glenoid defects (GD group) and 6 native glenoids (normal group). In the RF and N-RF groups, 6 rabbits were sacrificed at 6 or 12 weeks postoperatively for radiological and histological analyses of the reconstructed glenoid, and all rabbits in the GD and normal groups were sacrificed at 12 weeks. The radiological glenoid morphology was evaluated via micro-computed tomography. Moreover, the graft-glenoid healing and graft remodeling processes were determined using histological staining.

RESULTS

At 6 weeks, both the N-RF and RF groups had similarly improved radiological axial radian and en face area of the glenoid compared with the GD group, but the N-RF group showed superiority in restoration of the glenoid radian and area compared with the RF group at 12 weeks, with the native glenoid as the baseline. Histologically, the bone graft in both groups was substantively integrated into the deficient glenoid neck at 6 and 12 weeks, showing similar osseous healing processes at the graft-glenoid junction. Moreover, the bone graft histologically presented similar regenerated vascular density, total graft bone, and integrated graft bone in both groups. In contrast, the N-RF group had a different remodeling profile on radiological and histological analyses regarding regional bone resorption, mineralization, and fibrous tissue replacement during osseointegration.

CONCLUSION

Compared with rigid fixation, nonrigid fixation resulted in superior reconstructed glenoid morphology radiologically and similar graft-glenoid osseous healing histologically, showing different graft remodeling profiles of regional bone resorption, mineralization, and fibrous tissue replacement.

CLINICAL RELEVANCE

The nonrigid fixation technique can be feasible for FBB procedures to treat glenoid bone loss in anterior shoulder instability. More clinical evidence is required to determine its pros and cons compared with conventional rigid fixation.

Impact of Different Preparations of Tooth Graft vs Xenogeneic Bone Graft on Bone Healing: An Experimental Study

AIM

This study aims to compare the effect of demineralized xenogeneic tooth graft in its two forms, particulate and block, with bovine xenograft in the healing of a rabbit tibial bone defect model.

MATERIALS AND METHODS

Two monocortical bony defects were made in the right tibias of 36 rabbits, and were divided into four groups. Group I defects were left empty, while group II, III, and IV were filled with bovine xenograft, demineralized particulate tooth graft, and demineralized perforated block tooth graft, respectively for evaluation of the bone healing process. Three rabbits from each group were euthanized at 2, 4, and 6 weeks after surgery. The bone specimens were processed and stained with hematoxylin and eosin (H&E) and osteopontin (OPN) immunohistochemical staining. The results were subjected to image analysis and quantitative evaluation.

RESULTS

Demineralized particulate tooth graft showed the best bone healing capacity compared to all other groups at all time points tested, as it showed a large amount of the formed bone, rapid closure of the defect with a significant increase in OPN expression, and the least amount of the residual grafted particles.

CONCLUSION

In comparison to bovine xenograft and demineralized dentin block graft, the demineralized particulate tooth grafting material is a promising bone grafting substitute as it proved to be osteoconductive, biocompatible, and bioresorbable.

CLINICAL SIGNIFICANCE

Demineralized tooth grafting material can aid in the regeneration of large bone defects, leading to improvement in the filling of the bone defects which can help in oral and maxillofacial reconstruction.

Demineralized Dentin Matrix for Dental and Alveolar Bone Tissues Regeneration: An Innovative Scope Review

BACKGROUND

Dentin is a permeable tubular composite and complex structure, and in weight, it is composed of 20% organic matrix, 10% water, and 70% hydroxyapatite crystalline matrix. Demineralization of dentin with gradient concentrations of ethylene diamine tetraacetic acid, 0.6 N hydrochloric acid, or 2% nitric acid removes a major part of the crystalline apatite and maintains a majority of collagen type I and non-collagenous proteins, which creates an osteoinductive scaffold containing numerous matrix elements and growth factors. Therefore, demineralized dentin should be considered as an excellent naturally-derived bioactive material to enhance dental and alveolar bone tissues regeneration.

METHOD

The PubMed and Midline databases were searched in October 2021 for the relevant articles on treated dentin matrix (TDM)/demineralized dentin matrix (DDM) and their potential roles in tissue regeneration.

RESULTS

Several studies with different study designs evaluating the effect of TDM/DDM on dental and bone tissues regeneration were found. TDM/DDM was obtained from human or animal sources and processed in different forms (particles, liquid extract, hydrogel, and paste) and different shapes (sheets, slices, disc-shaped, root-shaped, and barrier membranes), with variable sizes measured in micrometers or millimeters, demineralized with different protocols regarding the concentration of demineralizing agents and exposure time, and then sterilized and preserved with different techniques. In the act of biomimetic acellular material, TDM/DDM was used for the regeneration of the dentin-pulp complex through direct pulp capping technique, and it was found to possess the ability to activate the odontogenic differentiation of stem cells resident in the pulp tissues and induce reparative dentin formation. TDM/DDM was also considered for alveolar ridge and maxillary sinus floor augmentations, socket preservation, furcation perforation repair, guided bone, and bioroot regenerations as well as bone and cartilage healing.

CONCLUSION

To our knowledge, there are no standard procedures to adopt a specific form for a specific purpose; therefore, future studies are required to come up with a well-characterized TDM/DDM for each specific application. Likely as decellularized dermal matrix and prospectively, if the TDM/DDM is supplied in proper consistency, forms, and in different sizes with good biological properties, it can be used efficiently instead of some widely-used regenerative biomaterials.

Comparative analysis of lateral maxillary sinus augmentation with a xenogeneic bone substitute material in combination with piezosurgical preparation and bony wall repositioning or rotary instrumentation and membrane coverage: a prospective randomized clinical and histological study

OBJECTIVES

The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation.

MATERIALS AND METHODS

Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches.

RESULTS

Forty implants were placed and 29 harvested biopsies could be evaluated. Duration of surgery, membrane perforations, and VAS were detected. Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%).

CONCLUSIONS

The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results.

CLINICAL TRIAL

clinicaltrials.gov NCT04811768.

CLINICAL RELEVANCE

Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.

Comparison of immunohistochemical analysis on sinus augmentation using demineralized tooth graft and bovine bone

Objectives

The purpose of this animal research was to compare bone regeneration in augmented rabbit maxillary sinuses treated with demineralized particulate human-tooth graft and anorganic bovine bone by immunohistochemical analysis.

Materials and Methods

Piezoelectric bilateral sinus augmentation was performed in eight adult rabbits. In the control group, anorganic bovine was grafted in the maxillary sinus following elevation of the sinus membrane. In the experimental group, demineralized human particulate tooth bone was grafted in the sinus. Bone regeneration in augmented sinuses was evaluated by immunohistochemical analysis using various markers of osteoprogenitor cells.

Results

The number of bromodeoxyuridine-labeled cells was significantly higher in the experimental group than in the control group at eight weeks. The immunoreactivity of proliferating-cell nuclear antigen was increased slightly in the experimental group relative to the control group at eight weeks. Other bone markers were expressed equally in the two groups.

Conclusion

In the rabbit maxillary sinus, higher osteoinduction was correlated with demineralized human particulate tooth bone grafting than with anorganic bovine grafting.

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.

Osseous Healing in Surgically Prepared Bone Defects Using Different Grafting Materials: An Experimental Study in Pigs

Regeneration of large jaw bone defects still remains a clinical challenge. To avoid incomplete bone repair, bone grafts have been advocated to support the healing process. This study comparatively evaluated new bone formation among a synthetic graft substitute, a human bone derivative, and a bovine xenograft. Materials were placed in 3 out of the 4 bone cavities, while 1 deficit was left empty, serving as a control, in mono-cortical defects, surgically prepared in the porcine calvaria bone. Animals were randomized in 2 groups and euthanized at 8 and 12 weeks. Harvested tissue specimens were qualitatively evaluated by histology. New bone formation was quantitatively measured by histomorphometry. Maximum new bone formation was noticed in defects grafted with beta-tricalcium phosphate b-TCP compared to the other bone substitutes, at 8 and 12 weeks post-surgery. Bovine and human allograft induced less new bone formation compared to empty bone cavity. Histologic analysis revealed that b-TCP was absorbed and substituted significantly, while bovine and human allograft was maintained almost intact in close proximity with new bone. Based on our findings, higher new bone formation was detected in defects filled with b-TCP when compared to bovine and human graft substitutes.

The Use of Tooth Derived Bone Graft Materials in Sinus Augmentation Procedures: a Systematic Review

OBJECTIVES

The goal of this systematic review was to assess the current literature about sinus augmentation procedure using different types of tooth derived bone graft materials, thorough analysing the outcomes of sinus grafting with tooth grafts compared to sinus grafting with xenografts, allografts and alloplasts by radiography and histomorphometry.

MATERIAL AND METHODS

An electronic search in the MEDLINE (NCBI PubMed and PubMed Central) database was conducted to identify articles concerning application of tooth bone grafts in sinus augmentation. The search was restricted to English language articles published in the last 10 years (December 2009 to March 2019).

RESULTS

In total, 21 articles were found, out of which 7 met the inclusion criteria and were included in the final synthesis. According to the type of diagnostic tool, data about graft material outcome in sinus was extracted, and included the residual alveolar height, augmented graft height, resorption height as seen in panoramic radiography and histomorphometric analysis of new bone formation and residual graft material.

CONCLUSIONS

Within the limitations of our review, we suggest that tooth derived graft materials are as successful as xenografts, allografts and alloplasts in sinus augmentation procedures according to the radiographic and histomorphometric showings. Additional wider research should be conducted in order to determine whether tooth derived graft materials are superior to the currently used materials.