Assessment of clinical outcomes and histomorphometric findings in alveolar ridge augmentation procedures with allogeneic bone block grafts: A systematic review and meta-analysis.

F Pérez-González,Lm Sáez-Alcaide,P Molinero-Mourelle,J López-Quiles,J Cortés-Bretón Brinkmann,L Sánchez-Labrador,A Limones

doi:10.4317/medoral.23353

Abstract

Background This systematic literature review aimed to evaluate the efficacy of allogeneic bone blocks for ridge augmentation by assessing block survival rates and subsequent implant survival, including post-surgical complications and histomorphometric analysis. Material and Methods An electronic and manual search among references, was conducted up to April 2019 by two independent authors. Inclusion criteria were: human clinical trials in which the outcomes of allogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant success rates. Results Seven articles fulfilled the inclusion criteria and were analyzed. A total of 323 allogeneic block grafts were monitored for a minimum of 12 months follow-up after surgery, of which thirteen (4.02%) failed. Regarding the cumulative implant survival rate, the weighted mean was 97.36%, computed from 501 implants. Histologic and histomorphometric analysis showed that allogeneic block grafts presented some clinical and microstructural differences in comparison with autologous block grafts. Conclusions Atrophic alveolar crest reconstruction with allogeneic bone block grafts would appear a feasible alternative to autologous bone block grafts, obtaining a low block graft failure rate, similar implant survival rate and fewer postoperative complications. Further investigations generating long term data are needed to confirm these findings. Key words:Allogeneic block, clinical outcome, ridge augmentation, dental implants.

Highlights

As the world population ages and dental loss increases, implant dentistry is subject to growing demands and new challenges
The objectives of this systematic review concern participants, interventions and outcome should respond following statement of questions: what are the survival rates of dental implants placed in allogeneic bone blocks? What are the blocks survival rates and what is the bone resorption rate of allogeneic bone blocks? Which surgical complications may occur? and which histologic and histomorphometric findings do we observe?
It had been decided to divide the studies into two groups: studies that used allogeneic bone blocks alone, and studies that compared allogeneic bone blocks with autologous bone blocks

Summary

Introduction

As the world population ages and dental loss increases, implant dentistry is subject to growing demands and new challenges. Clinical studies reporting data on: survival rates; technical, biologic and aesthetic complication rates of dental implants placed in allogeneic bone block grafted areas; bone blocks survival rates, histological and histomorphometric findings. It had been decided to divide the studies into two groups: studies that used allogeneic bone blocks alone, and studies that compared allogeneic bone blocks with autologous bone blocks The latter group failed to fulfill inclusion criteria due to insufficient follow-up times and presented very heterogeneous results, making comparison difficult. The meta-analysis results show that the overall survival rate of allogeneic block grafts was 94.52 %, Fig. 2 Both allogeneic bone blocks and implants were monitored for a minimum 12-month follow-up. In three works concerning allogeneic bone blocks, newly formed bone ranged between 31% and 42% on average; residual bone graft varied from 14% to 40%, while marrow and connective tissue ranged between 19.3 and 53.7% [12,16,17]

Findings

Discussion

Conclusion