Maxillary Sinus Augmentation With Calcium Phosphate Double-Coated Anorganic Bovine Bone: Comparative Multicenter Randomized Clinical Trial With Histological and Radiographic Evaluation

Bone volume and height changes for lateral window sinus floor elevation using two types of deproteinized bovine bone mineral: A retrospective cohort study of 1-4 years

OBJECTIVE

To compare bone volume and height changes of two types of deproteinized bovine bone mineral (DBBM) for lateral window sinus floor elevation (LSFE) with simultaneous implant placement.

MATERIALS AND METHODS

This retrospective cohort study involved 72 patients who underwent LSFE using low-temperature sintered cancellous bone-derived DBBM (C-DBBM) or high-temperature two-step sintered epiphyseal-derived DBBM (E-DBBM). Cone-beam computed tomography (CBCT) was acquired preoperatively, immediately postoperatively, 6 months and 1-4 years post-surgery. Bone volume (BV), apical bone height (ABH), endo-sinus bone gain (ESBG), and crestal bone level (CBL) were evaluated through three-dimensional fitting and superimposition. Linear mixed models (LMM) were employed to analyze factors influencing the reduction of BV (ΔBV) and ESBG (ΔESBG).

RESULTS

The E-DBBM group showed no significant change in BV 1-4 years post-surgery, while the C-DBBM group demonstrated a significant reduction (p = .006) with volume stability of 85.86%. Bone height in the E-DBBM group increased at 6 months and subsequently decreased at 1-4 years (p = .003). In the C-DBBM group, it decreased at 6 months (p = .014), then further decreased at 1-4 years (p = .001). ΔESBG was lower in the E-DBBM group than the C-DBBM group from immediate postoperative to 1-4 years (p = .009). LMM showed graft material type was the primary factor influencing ΔBV (p = .026) and ΔESBG (p = .003).

CONCLUSIONS

Within the limitations of this study, both types of DBBM could achieve favorable clinical outcomes. E-DBBM demonstrated enhanced stability in maintaining bone volume and height.

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.

A comparative analysis of particulate bovine bone substitutes for oral regeneration: a narrative review

PURPOSE

Particulate bovine bone substitutes (BS) are commonly used in oral regeneration. However, more literature is needed focusing on comparative analyses among various particulate bovine BS. This study evaluates pre-clinical and clinical data of different particulate bovine BS in oral regeneration.

METHODS

A narrative review was conducted by screening the PubMed database Included in the review were pre-clinical and clinical studies until 2024 comparing a minimum of two distinct particulate bovine BS. In addition to examining general data concerning manufacturing and treatment processes, biological safety, physical and chemical characteristics, and graft resorption, particular emphasis was placed on assessing pre-clinical and clinical data related to ridge preservation, sinus floor elevation, peri-implant defects, and various forms of alveolar ridge augmentation utilizing particulate bovine BS.

RESULTS

Various treatment temperatures ranging from 300 to 1,250 °C and the employment of chemical cleaning steps were identified for the manufacturing process of particulate bovine BS deemed to possess biosecurity. A notable heterogeneity was observed in the physical and chemical characteristics of particulate bovine BS, with minimal or negligible graft resorption. Variations were evident in particle and pore sizes and the porosity of particulate bovine BS. Pre-clinical assessments noted a marginal inclination towards favorable outcomes for particulate bovine BS subjected to higher treatment temperatures. However, clinical data are insufficient. No distinctions were observed regarding ridge preservation, while slight advantages were noted for high-temperature treated particulate bovine BS in sinus floor elevation.

CONCLUSIONS

Subtle variances in both pre-clinical and clinical outcomes were observed in across various particulate bovine BS. Due to inadequate data, numerous considerations related to diverse particulate bovine BS, including peri-implant defects, must be more conclusive. Additional clinical studies are imperative to address these knowledge gaps effectively.

Resorption Rates of Bone Graft Materials after Crestal Maxillary Sinus Floor Elevation and Its Influencing Factors

The aim of this study is to analyze the resorption rate of bone graft materials after crestal sinus floor elevation, study its influencing factors, and improve the long-term success rate of implants after crestal maxillary sinus floor elevation. Measurement and analysis were conducted at six postoperative timepoints (0 months, 6 months, 12 months, 18 months, 24 months, and 30 months) using cone beam computed tomography (CBCT) data on 31 patients from the Chenghuaxinguanghua Dental Clinic who underwent crestal maxillary sinus floor elevation, involving 38 graft sites. The materials resorption rates of the bone graft height (BH) and bone graft width (BW) were assessed. BH and BW resorption rates followed the same trend (p = 0.07), with BH and BW resorption rates decreasing with time (rBH = -0.32, p < 0.01; rBW = -0.18, p < 0.01), and were maximal in the 0-6 month interval, with BH and BW resorption rates of 3.42%/mth and 3.03%/mth, respectively. The average monthly BH and BW resorption rates in the 6-12 month interval rapidly decreased to 1.75%/mth and 1.29%/mth, respectively. The monthly BH and BW resorption rates in the 12-30 month intervals stabilized at 1.45%/mth (p > 0.05) and 1.22%/mth (p > 0.05), respectively. The higher the initial bone graft height (BH0), the lower the BH resorption rates (rBH = -0.98, p < 0.05), and the BW resorption rate was different for different graft sites (p = 0.01). The resorption rates of bone graft materials implanted through crestal maxillary sinus floor elevation decreased rapidly within the first 12 months post operation and remained stable after 12 months. BH0 was identified as a significant factor influencing the resorption rates of bone graft materials. These results could suggest dentists should pay attention to the trend of resorption rates over time and carefully manage the initial height of bone grafts and inspire the research of new bone grafting materials for crestal maxillary sinus floor elevation.

Residual Bone Height and New Bone Formation after Maxillary Sinus Augmentation Procedure Using Biomaterials: A Network Meta-Analysis of Clinical Trials

BACKGROUND

Different factors may affect new bone formation following maxillary sinus floor augmentation for the rehabilitation of posterior edentulous maxilla. The purpose of this study was to determine the influence of residual bone height (RBH) on new bone formation after lateral sinus augmentation utilizing different biomaterials, through a network meta-analysis (NMA).

METHODS

PUBMED, Scopus, and Web of Science electronic databases were searched until 31 December 2022 to obtain relevant articles. A hand search was also conducted. Randomised controlled studies on maxillary sinus augmentation comparing different grafting materials in patients with atrophic posterior maxilla, in need of prosthetic rehabilitation, were included. The risk of bias was assessed following the guidelines of the Cochrane Collaboration. The primary outcome was new bone formation (NBF), assessed histomorphometrically. The statistical analysis was performed by splitting the data according to RBH (<4 mm and ≥4 mm).

RESULTS

A total of 67 studies were eligible for conducting NMA. Overall, in the included studies, 1955 patients were treated and 2405 sinus augmentation procedures were performed. The biomaterials used were grouped into: autogenous bone (Auto), xenografts (XG), allografts (AG), alloplasts (AP), bioactive agents (Bio), hyaluronic acid (HA), and combinations of these. An inconsistency factor (IF) seen in the entire loop of the XG, AP, and Bio+AP was found to be statistically significant. The highest-ranked biomaterials for the <4 mm RBH outcome were XG+AG, XG+AP, and Auto. Similarly, the surface under the cumulative ranking curve (SUCRA) of biomaterials for ≥4 mm RBH was Auto, Bio+XG, and XG+Auto.

CONCLUSION

There is no grafting biomaterial that is consistently performing better than others. The performance of the materials in terms of NBF may depend on the RBH. While choosing a biomaterial, practitioners should consider both patient-specific aspects and sinus clinical characteristics.

Complications of sinus floor elevation procedure and management strategies: A systematic review

AIM

This systematic review aimed to investigates the types and incidences of complications following sinus floor elevations (SFE) along with their prevention and management strategies.

MATERIALS AND METHODS

Electronic database and hand search were conducted to screen the literature published from January 1960 to June 2021. The selected studies had to report well-described SFE techniques, complications during, and post-SFE. Data extraction included types of SFE techniques, complications, and their treatment strategies.

RESULTS

A total of 74 studies with 4411 SFE procedures met the inclusion criteria. Different SFE techniques demonstrated varying patterns for both complications and complication rates. Postoperative pain, swelling, and edema were widely reported. The most common complications that required intervention following Lateral SFE (LSFE) were sinus membrane perforation (SMP), wound dehiscence, graft exposure and failure, and sinusitis. LSFE had more SMPs and sinusitis cases compared with a transcrestal SFE (TSFE). The presence of benign paroxysmal positional vertigo following TSFE was significant in certain selected studies.

CONCLUSION

Given the inherent limitations, this systematic review showed distinct features of complications in SFE using varying techniques. Treatment planning for these procedures should incorporate strategies to avoid complication occurrence.

A Randomized Controlled Trial of Guided Bone Regeneration for Peri-Implant Dehiscence Defects with Two Anorganic Bovine Bone Materials Covered by Titanium Meshes

The aim of this study is to compare two low-temperature sintered anorganic bovine bone materials (ABBMs), Bio-Oss (Geistlich, Wolhusen, Switzerland) and A-Oss (Osstem, Seoul, Korea), for GBR in dehiscence defects. A single implant was placed simultaneously with GBR in the buccal or bucco-proximal osseous defect by double-layering of inner allograft and outer ABBM, covered by a preformed ultrafine titanium mesh and an absorbable collagen membrane. Grafted volume changes were evaluated by cone-beam computed tomography, taken preoperatively (T0), immediately after implant surgery (T1), after re-entry surgery (T2), and after delivery of the final restoration (T3). The density of the regenerated bone was assessed by measuring the probing depth on the buccal mid-center of the mesh after removing the mesh at T2. Postoperative sequelae were also recorded. Grafted volume shrinkage of 46.0% (0.78 ± 0.37 cc) and 40.8% (0.79 ± 0.33 cc) in the Bio-Oss group (8 patients) and A-Oss group (8 patients), respectively, was observed at T3 (p < 0.001). There were no significant differences in grafted volume changes according to time periods or bone density between the two groups. Despite postoperative mesh exposure (3 patients), premature removal of these exposed meshes and additional grafting was not necessary, and all implants were functional over the 1-year follow-up period. Both ABBMs with titanium meshes showed no significant difference in the quantity and density of the regenerated bone after GBR for peri-implant defects.

Radiographic and Histomorphometric Evaluation of Biomaterials Used for Lateral Sinus Augmentation: A Systematic Review on the Effect of Residual Bone Height and Vertical Graft Size on New Bone Formation and Graft Shrinkage

The aim of the present systematic review was to investigate the effect of residual bone height (RBH) and vertical bone gain on new bone formation (NBF) and graft shrinkage after lateral sinus lifts using different biomaterials.

METHODS

An electronic search was conducted on three databases to identify randomized controlled trials (RCTs) published until January 2021 with at least one follow-up at 6 months and at least five patients treated, comparing biomaterials used for maxillary sinus augmentation with a lateral approach. Graft volumetric changes, RBH, vertical bone gain, implant failure, and post-operative complications were evaluated. The risk of bias was assessed using the Cochrane tool.

RESULTS

We used 4010 identified studies, of which 21 were RCTs. Overall, 412 patients and 533 sinuses were evaluated. Only three publications had an overall low risk of bias. After 6 months, xenograft (XG) showed the least volume reduction (7.30 ± 15.49%), while autogenous graft (AU) was the most reabsorbed (41.71 ± 12.63%). NBF appeared to not be directly correlated with RBH; on the contrary, the overall linear regression analysis showed that NBF significantly decreased by 1.6% for each mm of postoperative vertical graft gain. This finding suggests that the greater the augmentation, the lower the NBF. A similar tendency, with a regression coefficient even higher than the overall one, was also observed with alloplast (AP) and XG.

CONCLUSIONS

The present results suggested that NBF was essentially independent of preoperative bone height. On the contrary, the smaller the volume was of the graft placed, the higher the amount of new bone formed, and the smaller the graft shrinkage was. Minimizing the augmentation volume might be beneficial to graft healing and stability especially when using AP and XG.

Xenograft materials in maxillary sinus floor elevation surgery: a systematic review with network meta-analyses

A systematic review and network meta-analysis was conducted to compare different commercially available xenograft materials used in maxillary sinus floor elevation surgery (MSFES). Embase, PubMed, the Cochrane Library, Web of Science, Scopus, LILACS, and grey literature were searched up to 13 July 2020. Only randomised controlled trials (RCTs) were included. A frequentist network meta-analysis using a random effects model compared different commercially available xenograft materials. The primary outcomes were the percentage of newly-formed bone and residual bone-substitute rate. Both were measured by histomorphometric analysis from bone biopsies obtained during preparation of the implant site. Of the 659 studies initially identified, 11 involving 242 MSFES were included in the quantitative analyses. A total of six bone-substitute materials were analysed (Bio-Oss® (Geistlich Pharma), InduCera® Dual Coat, Lumina-Bone Porous® (Critéria), Osseous® (SIN - Sistema de Implantes Nacional), THE Graft® (Purgo Biologics), and Osteoplant Osteoxenon® (Bioteck)). The P-score estimation showed that Osteoplant Osteoxenon® produced the most newly-formed bone and reabsorbed faster than other xenograft materials after six months. The combination of Bio-Oss® plus bone marrow aspirate concentrate (BMAC) significantly increased the percentage of newly-formed bone compared with Bio-Oss® alone. In contrast, the addition of Emdogain® (Straumann) and leucocyte and platelet-rich fibrin (L-PRF) to Bio-Oss® did not significantly improve the amount of regenerated bone. Study-level data indicated that the percentage of newly-formed bone differs among commercially available xenograft materials. Osteoplant Osteoxenon® seems to result in the highest amount of new bone in MSFES.

A biodegradable gelatin-based nanostructured sponge with space maintenance to enhance long-term osteogenesis in maxillary sinus augmentation

The search for bone substitutes that are biodegradable, ensure space maintenance, and have osteogenic predictability, is ongoing in the field of sinus augmentation. We thus compared the bone regeneration potential of nanostructured sponges (NS-Sponge) with that of collagen-stabilized inorganic bovine bones (BO-Collagen), gelatin sponges (Gelatin), and blood clots (Cont) in sinus augmentation of rabbits. NS-Sponge was prepared by thermally induced phase separation with porogen leaching techniques. All the materials were non-hemolytic and cytocompatible. The porous and nanofibrous NS-Sponge showed better dimensional stability to support cell growth and osteogenic differentiation. In vivo, the sinus membrane collapsed in Cont and Gelatin, while BO-Collagen and NS-Sponge maintained the elevated height as assessed by come-beam computed tomography. Limited bone regeneration was observed in Cont and Gelatin. In the entire implanted area, histological analysis revealed a higher percentage of new bone area at 4 weeks of BO-Collagen treatment; however, a significantly greater increase in new bone area was observed after 12 weeks of NS-Sponge treatment. The 12-week remnant NS-Sponge material was significantly lower than the 4-week remnant material. Overall, NS-Sponge may be highly recommended for sinus augmentation, as it exhibits numerous advantages, including excellent operability, clear imaging characteristics, space maintenance, biodegradability, and superior osteogenic potential.

Biomimetic Aspects of Oral and Dentofacial Regeneration

Biomimetic materials for hard and soft tissues have advanced in the fields of tissue engineering and regenerative medicine in dentistry. To examine these recent advances, we searched Medline (OVID) with the key terms “biomimetics”, “biomaterials”, and “biomimicry” combined with MeSH terms for “dentistry” and limited the date of publication between 2010–2020. Over 500 articles were obtained under clinical trials, randomized clinical trials, metanalysis, and systematic reviews developed in the past 10 years in three major areas of dentistry: restorative, orofacial surgery, and periodontics. Clinical studies and systematic reviews along with hand-searched preclinical studies as potential therapies have been included. They support the proof-of-concept that novel treatments are in the pipeline towards ground-breaking clinical therapies for orofacial bone regeneration, tooth regeneration, repair of the oral mucosa, periodontal tissue engineering, and dental implants. Biomimicry enhances the clinical outcomes and calls for an interdisciplinary approach integrating medicine, bioengineering, biotechnology, and computational sciences to advance the current research to clinics. We conclude that dentistry has come a long way apropos of regenerative medicine; still, there are vast avenues to endeavour, seeking inspiration from other facets in biomedical research.

Influence of General Mineral Condition on Collagen-Guided Alveolar Crest Augmentation

The local regeneration of bone defects is regulated by general hormone, enzyme, ion, and vitamin levels. General diseases and dysregulation of the human mineral system can impact this process, even in alveolar crest. The aim of this study is to investigate a relation between bone density, measured in two-dimensional X-rays, and general mineral condition of patients. The study included 42 patients on whom tooth extractions were performed. Data were divided into two groups: the region where collagen scaffold (BRM) was used and the reference region of intact normal bone (REF). Two-dimensional intraoral radiographs were taken in all cases just after the surgery (00 M) and 12 months later (12 M). Thyrotropin (TSH), parathormone (PTH), Ca²⁺ in serum, HbA1c, vitamin 25(OH)D₃, and spine densitometry were checked. Digital texture analysis in MaZda 4.6 software was done. Texture Index (TI: BRM 1.66 ± 0.34 in 00 M, 1.51 ± 0.41 in 12 M, and REF 1.72 ± 0.28) and Bone Index (BI: BRM 0.73 ± 0.17 in 00 M, 0.65 ± 0.22 41 in 12 M, and REF 0.80 ± 0.14) were calculated to evaluate bone regeneration process after 12 months of healing (TI (p < 0.05) and BI (p < 0.01) are lower in BRM 12 M than in REF). This showed a relation between BI and TSH (R² = 26%, p < 0.05), as well as a between BI and patient age (R² = 65%, p < 0.001), and a weak relation between TI and TSH level (R² = 10%, p < 0.05). This study proved that a collagen scaffold can be successfully used in alveolar crest regeneration, especially in patients with a high normal level of TSH in the middle-aged population.

New Oral Surgery Materials for Bone Reconstruction-A Comparison of Five Bone Substitute Materials for Dentoalveolar Augmentation

This article presents a comparison of bone replacement materials in terms of their ability to produce living bone image at the place of their implantation. Five bone replacement materials are compared (Osteovit-porous collagen, Cerasorb Foam-collagen scaffolding of synthetic β tricalcium phosphate, Osbone-synthetic hydroxyapatite, Endobone-deproteinized bovine-derived cancellous bone hydroxyapatite, and Cerasorb-synthetic β tricalcium phosphate). Intraoral radiographs are taken immediately after implantation and 12 months later. The texture analysis was performed to assess (texture index, TI) the level of structure chaos (entropy) in relation to the presence of longitudinal elements visible in radiographs (run length emphasis moment). The reference ratio of the chaotic trabecular pattern (Entropy) to the number of longitudinal structures, i.e., trabeculae (LngREmph), is 176:100 (i.e., 1.76 ± 0.28). Radiological homogeneity immediately after the implantation procedure is a result of the similar shape of its particles (Osbone, Endobone and Cerasorb) or radiolucency (Osteovit, Cerasorb Foam). The particles visible in radiographs were similar in the LngREmph parameters applied to the reference bone, but not in the co-occurrence matrix features. The TI for Osteovit during a 12-month follow-up period changed from 1.55 ± 0.26 to 1.48 ± 0.26 (p > 0.05), for Cerasorb Foam from 1.82 ± 0.27 to 1.63 ± 0.24 (p < 0.05), for Osbone from 1.97 ± 0.31 to 1.74 ± 0.30 (p < 0.01), and for Endobone from 1.86 ± 0.25 to 1.84 ± 0.25 (p > 0.05), The observed structure in the radiological image of bone substitute materials containing calcium phosphates obtains the characteristics of a living bone image after twelve months.