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

Gene expression, micro-CT and histomorphometrical analysis of sinus floor augmentation with biphasic calcium phosphate and deproteinized bovine bone mineral: A randomized controlled clinical trial

AIMS

The aim of this randomized controlled clinical trial was to compare the gene expression, micro-CT, histomorphometrical analysis between biphasic calcium phosphate (BCP) of 70/30 ratio and deproteinized bovine bone mineral (DBBM) in sinus augmentation.

MATERIALS AND METHODS

Twenty-four patients in need for sinus floor augmentation through lateral approach were randomized into BCP 70/30 ratio or DBBM. After at least 6 months of healing, a total of 24 bone specimens were collected from the entire height of the augmented bone at the area of implant placement and underwent micro-CT, histomorphometric and gene expression analysis. The 12 bone specimens of BCP 70/30 ratio were equally allocated to micro-CT and histologic analysis (test group, n = 6) and gene expression analysis (test group, n = 6). Similarly, the 12 bone specimens of DBBM were also allocated to micro-CT and histologic analysis (control group, n = 6) and gene expression analysis (control group, n = 6). The newly formed bone, remaining graft materials and relative change in gene expression of four target genes were assessed.

RESULTS

The micro-CT results showed no statistically significant difference in the ratio of bone volume to total volume (BV/TV ratio) for the two groups (BCP 41.51% vs. DBBM 40.97%) and the same was true for residual graft material to total volume (GV/TV ratio, BCP 9.97% vs. DBBM 14.41%). Similarly, no significant difference was shown in the histological analysis in terms of bone formation, (BCP 31.43% vs. DBBM was 30.09%) and residual graft area (DBBM 40.76% vs. BCP 45.06%). With regards to gene expression, the level of ALP was lower in both groups of bone grafted specimens compared with the native bone. On the contrary, the level of OSX, IL-1B and TRAP was higher in augmented bone of both groups compared with the native bone. However, the relative difference in all gene expressions between BCP and DBBM group was not significant.

CONCLUSIONS

The BCP, HA/β-TCP ratio of 70/30 presented similar histological and micro-CT outcomes in terms of new bone formation and residual graft particles with DBBM. The gene expression analysis revealed different gene expression patterns between augmented and native bone, but showed no significant difference between the two biomaterials.

Potentials of pure xenograft materials in maxillary ridge augmentation: A case series

Many patients require edentulous ridge augmentation for dental implant placement. The main objective of this study was to evaluate the results of maxillary edentulous ridge augmentation exclusively with xenograft materials with and without simultaneous sinus floor elevation. This study reports the data retrieved from the records of 16 patients. The treatment outcome was assessed at least 6 months, postoperatively. Paired samples t-test or Wilcoxon Signed Rank test was used to compare the pre-and postoperative ridge dimensions. Dental implants were placed simultaneously in 7 patients, while 9 patients underwent delayed implant placement. In total, 68 implants were placed, and 12 patients also underwent maxillary sinus floor augmentation. A significant bone gain was achieved in both horizontal and vertical dimensions of edentulous maxillary ridges (P < 0.001). Ridge width increased by an average of 4.35 ± 1.90 mm (95% CI: 3.84 to 4.85 mm) while ridge height in areas of sinus floor augmentation increased by 8.19 ± 2.91 mm (95% CI: 7.33 to 9.05 mm). Within the study limitations, it appears that maxillary ridge augmentation according to the guided bone regeneration (GBR) protocols with exclusive use of xenograft particulate materials can provide optimal bone quantity for dental implant placement.

The impact of deproteinized bovine bone particle size on histological outcomes in sinus floor elevation: a systematic review and meta-analysis

OBJECTIVES

The main purpose of this study was to evaluate whether large granular bovine bone can be as effective as small granular bovine bone in maxillary sinus floor elevation.

METHODS

A comprehensive online search of eligible articles was conducted using PubMed, EMBASE, Cochrane Library, Scopus, and Web of Science, and a systematic review and meta-analysis was performed from establishment to February, 2023. The outcome indicators were the percentage of connective tissue, the percentage of newly formed bone and the percentage of residual xenograft respectively. The meta-analysis was conducted by using the Stata 15.1 (Stata Conpernarn, USA) and Review Manager software5.4.1.

RESULTS

After careful screening and review, a total of 4 studies were included for systematic review and meta-analysis. The data were extracted to compare the histological performance of bovine bones with different particle sizes after maxillary sinus elevation. No significant differences were found in the percentage of connective tissue, the percentage of newly formed bone, and the percentage of residual xenograft.

CONCLUSION

In this study, a systematically review of the previous literature showed that similar histological results were obtained for both large-particle bovine bone and small-particle bovine bone. Therefore, the large granular bovine bone and the small granular bovine bone were equally effective in maxillary sinus elevation. It is difficult to make conclusion from limited evidence from four studies. More clinical evidence was needed.

Comparison of osteogenesis and osseointegration following implant placement with simultaneous maxillary sinus augmentation using particulate and collagenated block types of deproteinized porcine bone mineral: a radiographic and histomorphometric analysis

OBJECTIVES

This study aimed to compare osseointegration and osteogenesis after single-stage maxillary sinus augmentation with the lateral window using particulate deproteinized porcine bone mineral (PDPBM) and collagenated block deproteinized porcine bone mineral (BDPBM).

MATERIALS AND METHODS

Bi-maxillary premolars of six beagle dogs were extracted. Eight weeks later, an implant was placed into each augmented sinus with PDPBM or BDPBM according to a split-mouth design. Eight weeks later, all specimens were harvested. Each specimen was separated into the region of interest with the implant (ROI-I) and region of interest with sinus augmented area (ROI-S) 5 mm away from ROI-I. ROI-I and ROI-S were evaluated through micro-computed tomography and histomorphometry.

RESULTS

Bone substitute insertion took longer for the PDPBM group than for the BDPBM group (P = 0.002). In ROI-I, three-dimensional bone-to-implant contact (BIC) did not show statistically significant differences between the groups. Two-dimensional BIC also showed comparable values for both groups. In ROI-S, the graft material volume/tissue volume, trabecular bone pattern factor, and structural model index were higher in the BDPBM group than in the PDPBM group (P < 0.05). The proportions of new bone, graft material, and connective tissue were not significantly statistically different between groups. Less new bone was found in the apical area than in the coronal or middle areas in the BCPBM group (P < 0.05).

CONCLUSIONS

BDPBM may save time in inserting bone substitutes and provide comparable osteogenesis and osseointegration to PDPBM.

CLINICAL RELEVANCE

When performing sinus augmentation, BDPBM might improve operator's convenience with comparable biological results compared to PDPBM.

Radiographic Analysis of Graft Dimensional Changes in Transcrestal Maxillary Sinus Augmentation: A Retrospective Study

Background. The maxillary sinus lift is a popular and predictable technique associated with implant-supported rehabilitation of the severely atrophic maxilla. The aim of the present retrospective study was to investigate the effectiveness of transcrestal maxillary sinus augmentation and the graft resorption pattern using different heterologous bone substitutes. Methods. A total of 75 sinus-grafting procedures were performed and 89 implants were placed in 66 patients, 24 males and 42 females, with mean age 67.9 ± 10.64 years (range 43−84 years). Nineteen subjects were smokers. The mean follow-up period was 93.33 ± 54.71 months (range 14−240 months). Clinical and radiographical evaluations were performed. Graft height and width were measured at baseline and at the latest follow-up. Results. Mesiodistal and vertical resorption averaged 9.3 ± 20.7% (standard deviation), and 5.04 ± 9.9% of the postoperative size, respectively, considering the graft as the unit. Linear regression analysis showed that graft resorption in both the vertical and the mesiodistal dimension is independent of the follow-up time. Conversely, there was a trend for greater resorption when increasing the postoperative graft size, in both vertical (p = 0.001) and horizontal (p = 0.007) dimensions. When grouping the dimensional changes by graft particle size (only small (<300 μm) particles, combination of small and medium (>500 μm)/large (>1000 μm) particles, and only medium/large particles), there was a trend for greater resorption associated with smaller particles, but it was not significant; neither in the mesiodistal nor in the vertical dimension (p = 0.17 and p = 0.25, respectively). No implant was lost during the observation period. In conclusion, the transcrestal technique for maxillary sinus augmentation documented a high level of predictability. The low clinical morbidity and the contextual dental implant positioning is clinically useful in relation to a significant reduction of the time required for implant restoration, a consistent decrease of the number of surgical phases, and a cost-effectiveness approach for the rehabilitation. The graft resorption pattern in all cases was compatible with persistent implant protection and support.