"Xenogeneic Bone Block in Lateral Ridge Augmentation: Where Are We Now?' A Systematic Review and Meta-Analysis.

Abstract

Purpose: This systematic review and meta-analysis aimed to investigate the clinical outcomes of xenogeneic bone blocks (XBB) used for lateral ridge augmentation, specifically focusing on bone gain, graft survival, and implant survival.

Materials and methods: Data search was conducted in Pubmed, Embase, and ClinicalTrial.gov for randomized controlled trials (RCTs), and prospective cohort studies up to March 1, 2024. Horizontal bone gain (HBG), horizontal bone resorption (HBR), graft survival rate, and implant survival rate were analyzed. Cochrane Risk of Bias Tool 2 and Newcastle-Ottawa Scale were applied to assess the quality and risks of the included studies.

Results: Four RCTs and five prospective cohortstudies, comprised 120 graft sites and 141 implants in total were included for the meta- analysis. Non-comparative analysis resulted in a weighted mean horizontal bone gain (HBG) of 4.38 mm and horizontal bone resorption (HBR) of 0.85 mm. Comparative analysis with data from 4 RCTs that paired xenogeneic bone block (XBB) with autogenous bone block (ABB) exhibited a statistically significant greater HBG in XBB, with a mean difference of 0.72mm (95% CI=0.067 to 1.382, p=0.031, I2=28.2%). The weighted graft survival rate for XBB was 91.3% (95% CI = 76.6% to 97.1%, I2 = 58.0 %), and the weighted implant survival rate was 84.3% (95% CI = 72.6% to 91.6%, I2 = 31.6 %). Histologically, mean percentage of mineralized vital bone in XBB ranged from 11.6% to 29.8%, and the resorption rate ranged from 7.3% to 21%.

Conclusion: The utilization of xenogeneic bone block for lateral ridge augmentation demonstrates an acceptable survival rate and yields an adequate volume of bone for subsequent implant therapy. Nonetheless, the survival rate of implants placed in ridges augmented with xenogeneic blocks is less favorable when compared to those augmented with autogenous block grafts.