Histological Analysis of New Bone Formation Using Bone Substitutes, with and Without Autograft: A Systematic Review
Mohammad Hosseini Hooshiar1, Zohreh Moradipour2, Amir Moeintaghavi3
1Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Background:
No definitive guidelines exist regarding the use of xenografts or allografts with or without autogenous bone grafts (ABGs) in guided bone regeneration (GBR). While radiographic systematic reviews have extensively explored this topic, a substantial knowledge gap exists in the current understanding of the histological outcomes of combining ABGs with these bone substitutes. This systematic review evaluates whether adding ABGs to xenografts or allografts improves new bone formation in histomorphometric outcomes.
Purpose:
It is essential to understand histological outcomes, particularly regarding new bone formation, as they offer direct evidence of the biological effectiveness of bone regeneration procedures, providing insights that radiographic assessments alone cannot provide. This systematic review poses a fundamental question: Does adding ABGs to xenografts or allografts in GBR improve new bone formation?
Materials And Methods:
This systematic review was registered in PROSPERO (CRD42021282176). An electronic search encompassed the Scopus, Embase, Web of Science, PubMed/Medline, and Cochrane databases until August 1, 2024, with no language restrictions. The systematic review incorporated human-randomized clinical trials and animal-randomized studies focusing on GBR using bone substitutes, with and without ABGs. The percentage of new vital bone formation served as the primary outcome measure. Soft tissue formation or residual graft particles were considered secondary outcomes.
Results:
Initially, 2,253 studies were identified. The screening process indicated that six studies (three randomized clinical trials and three randomized animal studies) met the inclusion criteria. An animal studies meta-analysis revealed no significant differences between groups in new bone formation, soft tissue formation, or remaining graft material, with low heterogeneity. Meta-analysis was not feasible for human studies due to the high risk of bias and small sample sizes.
Conclusion:
A meta-analysis of animal studies (approximately 10-16 weeks) demonstrated that the addition of ABGs to xenografts or allografts in GBR did not significantly enhance new bone formation. The findings from available human clinical trials align with these results, although a meta-analysis of human studies was not feasible due to the high risk of bias and small sample sizes.
