Prospective and Randomized Evaluation of ChronOS and Bio-Oss in Human Maxillary Sinuses: Histomorphometric and Immunohistochemical Assignment for Runx 2, Vascular Endothelial Growth Factor, and Osteocalcin

Exploring the potential of calcium-based biomaterials for bone regeneration in dentistry: a systematic review

INTRODUCTION

Regenerative medicine emerged as a promising strategy for addressing bone defects, with several bone grafts currently being used, including autografts, allografts, xenografts and alloplasts. Calcium-based biomaterials (CaXs), a well-known class of synthetic materials, have demonstrated good biological properties and are being investigated for their potential to facilitate bone regeneration. This systematic review evaluates the current clinical applications of CaXs in dentistry for bone regeneration.

EVIDENCE ACQUISITION

A comprehensive search was conducted to collect information about CaXs and their applications in the dental field over the last ten years. The search was limited to relevant articles published in peer-reviewed journals.

EVIDENCE SYNTHESIS

A total of 72 articles were included in this scoping review, with eight studies related to periodontology, 63 in implantology and three in maxillofacial surgery respectively. The findings suggest that CaXs hold promise as an alternative intervention for minor bone regeneration in dentistry.

CONCLUSIONS

Calcium-based biomaterials have shown potential as a viable option for bone regeneration in dentistry. Further research is warranted to fully understand their efficacy and safety in larger bone defects. CaXs represent an exciting avenue for researchers and clinicians to explore in their ongoing efforts to advance regenerative medicine.

Clinical Assessment of Biphasic Calcium Phosphate in Granules and Paste Forms in Human Maxillary Sinus Bone Augmentation: A Randomized, Split-Mouth Clinical Trial

The aim of the present study is to compare the biphasic calcium phosphate (BCP) using two different forms-(1) granules and (2) paste-in human maxillary sinus bone reconstruction as a split-mouth study using histomorphometric and immunolabeling for osteocalcin. Ten patients with bilateral maxillary posterior partial edentulism were selected in order to reconstruct bone height. They were divided into two groups: BCPG and BCP-P. After six months of bone healing, biopsies were harvested to assess the new bone formation and immunostaining for osteocalcin. The BCP g group had the following results: mean of bone formation in pristine bone 49.4 ± 21.6%, intermediate 49.4 ± 16.2%, and apical 55.3 ± 21.4%. The group BCP-P had a mean of 41.9 ± 17.3% in the pristine bone region, 37.5 ± 7.8% for intermediate, and 39.0 ± 13.5% for apical. The osteocalcin immunolabeling was high for both groups, demonstrating bone calcification. Thus, the two biomaterials present suitable results for the placement of dental implants.

The Role of Bone Grafts in Preventing Medication-Related Osteonecrosis of the Jaw: Histomorphometric, Immunohistochemical, and Clinical Evaluation in Animal Model

Objective

To evaluate the effects of inorganic bovine bone graft (Lumina Bone, Criteria, Brazil) and beta-tricalcium phosphate (β-TCP) graft (ChronOS, Synthes, Brazil) in rats with the risk of developing post-extraction medication-related osteonecrosis of the jaw (MRONJ).

Methods

Eighteen male Wistar rats weighing 350 to 450 g were induced to develop MRONJ using zoledronic acid for 5 weeks. In the sixth week, the right maxillary first molar was extracted. The animals in Group I (G1) did not receive bone grafts after tooth extraction, while Group II (G2) animals received inorganic bovine bone grafts, and Group III (G3) animals received beta-tricalcium phosphate (β-TCP) grafts. Clinical evaluation and histomorphometric and immunohistochemical analyses were performed. ANOVA and Tukey's statistical tests were used and a level of significance was considered to be 5%.

Results

In the clinical evaluation, animals from G2 and G3 did not present clinical manifestations of osteonecrosis, unlike the control group (G1) animals, which presented necrotic bone tissue exposure in all samples. In the histomorphometric evaluation, animals in G3 showed greater formation of bone tissue (66%) and less formation of bone lacuna (18%) than animals in G1 (58%/32%) and in G2 (59%/27%) (P < 0.05). Moderate (++) immunostaining was observed in G2 and G3 for RANKL, TRAP, and OC, while G1 showed moderate (++) labeling for OC and mild (+) immunostaining for TRAP and RANKL.

Conclusions

Greater formation of bone tissue and fewer bone lacunae were found in animals treated with β-TCP. In clinical evaluation, bone graft groups presented with the clinical manifestation of MRONJ and showed higher intensity of immunostaining for TRAP and RANKL. Despite the limitations of experimental animal studies, the results of this work may assist in the development of future clinical research for the prevention of MRONJ.

Which Histometric Analysis Approach Is More Reliable for Assessing Histological Bone Tissue Samples?

This study aims to evaluate the grid of Merz and ImageJ methods for histometric quantification, verifying which is more reliable and defining which is most suitable based on the time required to perform. Thirty histological samples of maxillary sinuses grafted with xenografts were evaluated using an optical light microscope attached to an image capture camera and connected to a microcomputer. The images were digitalized and recorded as a TIFF image, and the new bone formation was evaluated using the grid of Merz and ImageJ. The Bland–Altman analysis was used to identify the agreement between the methods and determine suitable future research options. The timing of the quantification was also performed to identify a possible advantage. The mean value for the quantification analysis timing for the grid of Merz was 194.9 ± 72.0 s and for ImageJ was 871.7 ± 264.4, with statistical significance between the groups (p = 0.0001). The Bland–Altman analysis demonstrated a concordance between the methods, due to the bias being next to the maximum concordance (−1.25) in addition to the graphic showing the scattering points next to the mean of differences and inside of limits of agreement. Thus, it was demonstrated that the grid of Merz presents reliable outcomes and advantages over the ImageJ methodology regarding the time spent to contour the areas of interest.

The impact of deproteinized bovine bone particle size on histological and clinical bone healing outcomes in the augmented sinus: A randomized controlled clinical trial

OBJECTIVE

The effect of different deproteinized bovine bone mineral (DBBM) particle sizes on bone healing in maxillary sinus floor augmentation remains unclear. This study compared the newly formed tissue and angiogenesis-related bone healing after sinus floor augmentation using large or small DBBM particles.

MATERIALS AND METHODS

Overall 32 patients were randomly divided into two groups using either large (1-2 mm) or small (0.25-1 mm) DBBM particles for sinus floor augmentation. After 6 months, the mineralized tissue volume was calculated using micro-computed tomography (micro-CT) analysis. The newly formed tissue composition was histomorphometrically analyzed. Angiogenesis was also examined by means of vascular endothelial growth factor (VEGF) expression. Implant failure and marginal bone loss were measured at a 1-year follow-up. Statistical analysis was performed using independent samples t-test.

RESULTS

Micro-CT analysis demonstrated that grafting with large particles resulted in higher bone volume (6.99 ± 2.72 mm³ , p = 0.002) and Bone Volume/Tissue Volume (0.25 ± 0.1, p = 0.03) compared with small particles (3.76 ± 1.83 mm³ and 0.14 ± 0.13, respectively). Small particles showed higher non-mineralized tissue volume (26.31 mm³ ) compared with large particle group (17.4 ± 5.34 mm³ ) with p = 0.001. The histological data revealed significantly higher area of newly formed bone (32.15% ± 14.04% for the large particle and 15.99% ± 14.12% for the small particle groups, p = 0.004). Likewise, non-mineralized tissue was significantly greater in the small particle group (66.48% ± 20.97%) compared with the large particle group (44.36%, p = 0.016). Moreover, use of large particles resulted in a significantly higher VEGF staining intensity score and VEFG positive cells. No implant failure was recorded in both groups, while no difference was found in terms of marginal bone loss at the 1-year follow-up.

CONCLUSIONS

Sinus floor augmentation using large DBBM particles resulted in more angiogenesis expression, higher bone volume, and new bone formation at 6 months after sinus augmentation. However, clinical outcomes with regards to implant placement were similar in both groups.

Evaluation of Two Beta-Tricalcium Phosphates with Different Particle Dimensions in Human Maxillary Sinus Floor Elevation: A Prospective, Randomized Clinical Trial

This study aimed to compare two beta-tricalcium phosphates with different particle sizes in human maxillary sinuses lifting. The immunolabeling of cells for RUNX2 and VEGF were performed to evaluate the osteoblast precursor cells and the vascular formation after 6 months of bone repair. Ten maxillary sinuses were grafted with autogenous bone graft (Group 1), 10 were grafted with ChronOs^® (Group 2), and 10 were grafted with BETA-TCP^® (Group 3). After 6 months of bone healing, biopsies were obtained to assess the new bone formed by histomorphometric and immunohistochemical evaluation for RUNX2 and VEGF. The mean bone formation for Group 1 was 51.4 ± 17.4%. Group 2 presented 45.5 ± 9.9%, and Group 3 conferred 35.4 ± 8.0% of new bone formation. The RUNX2 offered low for Groups 1 and 2 with high cellular activity for osteoblast in Group 3. The VEGF immunolabeling was moderate for Groups 1 and 2 and intense for Group 3. In conclusion, it was possible to show that the bone substitutes evaluated in the present study presented suitable outcomes for bone regeneration, being an alternative for the autogenous bone graft in maxillary sinus bone height reconstruction.

The Application of Beta-Tricalcium Phosphate in Implant Dentistry: A Systematic Evaluation of Clinical Studies

The demand for synthetic graft materials in implant dentistry is rising. This systematic review aims to evaluate the survival rate of dental implants placed simultaneously with bone regeneration procedures using the material β-tricalcium phosphate, one of the most promising synthetic graft materials. The electronic search was conducted in PubMed, Scielo, and the Cochrane Central Register of Controlled Trials. Five randomized clinical trials, one non-randomized controlled clinical trial and four observational studies without control group were include. Implant survival rate and other clinical, radiographic, and histological parameters did not differ from those of implants placed simultaneously with another type of graft material, or placed in blood clots or natural alveolar ridges. Based on the available literature, β-tricalcium phosphate seems to be a promising graft material in implant dentistry. Nevertheless, more randomized clinical trials, with long follow-up periods, preoperative and postoperative CBCT, and histological analysis, are necessary to assess its long-term behavior.

The new bone formation in human maxillary sinuses using two bone substitutes with different resorption types associated or not with autogenous bone graft: a comparative histomorphometric, immunohistochemical and randomized clinical study

OBJECTIVE

The aim of this study is to evaluate the new bone and connective tissue formation and the biomaterial remaining after maxillary sinus bone augmentation using 5 different bone substitutes. The osteocalcin immunolabeling was performed to demonstrate their calcification and the possibility of receiving dental implants.

METHODOLOGY

40 patients underwent maxillary sinus bone augmentation and were divided in 5 groups: Group 1 with 8 maxillary sinuses were grafted with autogenous bone graft (AB); Group 2 with 8 maxillary sinuses grafted with bioactive glass (BG); Group 3 with 8 maxillary sinuses grafted with bioactive glass added to autogenous bone graft (BG + AB) 1:1; Group 4 with 8 maxillary sinuses grafted with Bio-Oss (BO) and Group 5 with 8 maxillary sinuses grafted with Bio-Oss added to autogenous bone graft (BO + AB) 1:1.

RESULTS

In group AB, 37.8% of bone was formed in the pristine bone region, 38.1% in the intermediate and 44.5% in the apical region. In group BG, 43.6% was formed in the pristine bone, 37% in the intermediate and 49.3% in the apical region. In group BG + AB 1:1, 39.0% was formed in the pristine bone region, 34.8% in the intermediate and 36.8% in apical region. In group BO, 33.4% was formed in the pristine bone, 32.5% in the intermediate and 34.3% in the apical region. In group BO + AB 1:1, 32.8% was formed in the pristine bone, 36.1% in intermediate and 27.8% in the apical regions. The immunolabeling for osteocalcin showed an intensive staining for all groups, which could demonstrate the calcification of the bone formed.

CONCLUSION

This study showed that the groups evaluated formed a suitable lamellar bone in the maxillary sinus reconstruction after six months of bone healing, thus being indicated to receive dental implants.

Maxillary Sinus Floor Augmentation with Autogenous Bone Graft Alone Compared with Alternate Grafting Materials: a Systematic Review and Meta-Analysis Focusing on Histomorphometric Outcome

Objectives

The objective of present systematic review was to test the hypothesis of no difference in histomorphometric outcome after maxillary sinus floor augmentation with autogenous bone graft alone compared with alternate grafting materials applying the lateral window technique.

Material and Methods

MEDLINE (PubMed), Embase and Cochrane library search in combination with hand-search of relevant journals were conducted. Human studies published in English until the 25^th of March, 2020 were included. Histomorphometric outcomes were evaluated by descriptive statistics and meta-analysis including 95% confidence interval (CI).

Results

Electronic search and hand-searching resulted in 1902 entries. Sixteen randomized controlled trials with unclear risk of bias fulfilled the inclusion criteria. Descriptive statistics showed comparable or improved histomorphometric outcomes with autogenous bone graft. Meta-analysis revealed a mean difference of -7.1% (CI = -11.0 to -3.2) indicating a significant higher amount of bone after maxillary sinus floor augmentation with autogenous bone graft compared with alternate grafting materials. Subgroup analysis demonstrated a non-significantly differences of -3.7% (CI = -10.9 to 3.4), -11.5% (CI = -25.9 to 2.8), 2.2% (CI = -16.9 to 21.3), and -4.6% (CI = -14.4 to 5.2), when autogenous bone graft was compared with allogeneic bone graft, xenograft, composite grafting materials involving xenograft or synthetic biomaterial mixed with autogenous bone graft, respectively.

Conclusions

Maxillary sinus floor augmentation with autogenous bone graft seems to facilitate improved histomorphometric outcomes compared with alternate grafting materials. However, the included studies were characterised by an unclear risk of bias and various methodological confounding factors. Hence, the conclusions drawn from the results of present study should be interpreted with caution.

Guided Lateral Sinus Lift Procedure Using 3-Dimensionally Printed Templates for a Safe Surgical Approach: A Proof-of-Concept Case Report

The purpose of this article was to present a guided lateral window sinus lift procedure with the aid of a fully digital workflow using surgical templates for window osteotomy preparation and implant placement. A 22-year-old patient with insufficient residual bone height in the posterior maxilla was treated with a maxillary sinus augmentation procedure with a lateral window technique and simultaneous implant installation using 3-dimensionally printed surgical guides. The surgical guides, used for the preparation of both the lateral window and the implant site according to the optimal prosthodontic and anatomic position, were based on a fully digital workflow and virtual pre-planning with modified implant-planning software. Successful functional and esthetic rehabilitation of the patient was accomplished using standard surgical techniques and instruments but an innovative method for the production and application of surgical templates ensured a precise and safe approach for the lateral window osteotomy preparation. This guided lateral window sinus lift technique may reduce the incidence of surgical complications and failures and enhance patient-related outcomes.

The Human Amniotic Mesenchymal Stem Cells (hAMSCs) Improve the Implant Osseointegration and Bone Regeneration in Maxillary Sinus Floor Elevation in Rabbits

Insufficient bone height in the posterior maxilla is a challenging problem in dental implantation. Bio-Oss, though routinely used in maxillary sinus floor elevation (MSFE), is not osteoinductive. Human amniotic mesenchymal cells (hAMSCs) isolated from placental tissues have potential for multidifferentiation and immunomodulatory properties and can be easily obtained without the need for invasive procedures and without ethical concerns. This is the first study to use hAMSCs to improve implant osseointegration and bone regeneration after MSFE. Human AMSCs were loaded into a fibrin gel and injected into rabbit MSFE models. The rabbits were assigned to four groups (n = 3 per group), i.e., the control group, the hAMSC group, the Bio-Oss group, and the hAMSC/Bio-Oss group. The animals were sacrificed at postsurgery for four and twelve weeks and evaluated by histology and immunohistochemistry. Bone volume, bone volume/tissue volume, bone-to-implant contact ratio, and vessel-like structures in the hAMSC/Bio-Oss group were significantly better than those in other groups in the peri-implant and augmented areas. Immunofluorescence staining showed that alkaline phosphatase (ALP) activities of two hAMSC groups were higher than those of the other two groups. Sequential fluorescent labeling was performed in all of the 12-week groups. Observations showed that hAMSCs accelerated mineralized deposition rates on implant surfaces and in bone-augmented areas. These data demonstrated that hAMSCs could enhance implant osseointegration and bone regeneration after MSFE and might be used to optimize dental implantation in the future.

Commercially available bone graft substitutes: the impact of origin and processing on graft functionality

Development of effective and cost-efficient bone tissue engineering grafts has been the key area of research for regenerative medicine, yet an ideal grafting material has remained elusive due in large part to the highly dynamic nature of bone. A wide array of materials, both natural and synthetic, have been implemented as potential candidates for commercially available products, yet the gold standard for grafting material still remains autogenous bone. We review currently commercially available bone graft materials and relevant graft characteristics that impact the effectiveness of tissue repair, emphasizing the advantages and disadvantages of materials based on composition and origin. Examined materials were selected through a web-based search for readily accessible and clinically applicable graft materials. Grafts were then categorized according to material source to examine advantages and disadvantages associated with allogenic, xenogeneic, synthetic materials. Lastly, the application of bioactive molecules onto these basal grafts is explored to illustrate the enhancement and regulative capacity of these additives on traditional osteobiologic materials.

Is Impregnation of Xenograft with Caffeine Effective on Bone Healing Rate in Mandibular Defects? A Pilot Histological Animal Study

Introduction and Aim

The aim of this study was to evaluate the effect of two concentrations of caffeine (1.5% and 3%) powder added to Bio-Oss xenograft on bone healing rate of iatrogenic mandibular defects in dogs.

Materials and Method

The researchers implemented a pilot study on ten male adult mongrel dogs. Two 4-mm circular critical-sized defects were trephined on each side of the mandibular body (a total of 4 defects for each dog). One of the defects remained empty as a control group. The other three defects in each case were randomly filled with 1.5% or 3% caffeinated Bio-Oss or pure Bio-Oss. The mandible specimens were sent for histological and histomorphometric assessments, 4 months postoperatively. Our predictor variable was the type of bone substitute. The study outcomes were new bone formation, angiogenesis, and fibrosis. The p value was set at 0.05 using SPSS 16.

Results

The histological assessment showed that the administration of 1.5% caffeinated Bio-Oss to mandibular defects caused more angiogenesis and more new bone formation as well as less fibrosis compared to the other groups (p < 0.05).

Conclusion

This study suggested that the application of 1.5% caffeinated Bio-Oss in bone defects of dogs resulted in the higher new bone formation. However, further clinical trials are needed to support its relevancy.