Histomorphometric outcomes after lateral sinus floor elevation procedure: a systematic review of the literature and meta-analysis

Objectives: The aim of the present systematic review of the literature was to evaluate biomaterials performances considering new bone formation estimated through histomorphometric analysis of bone biopsies from human subjects after maxillary sinus floor elevation. Materials and methods: An electronic and manual search was performed to retrieve articles showing histomorphometric data of bone biopsies performed after sinus floor elevation surgery. Recorded data were statistically analyzed evaluating percentage of new bone volume, residual biomaterial, and connective/soft tissues in the biopsies. A meta-analysis of comparative studies was also performed. Results: After article selection process, 84 articles were included in the quantitative synthesis and 16 of them in the meta-analysis of comparative studies. The use of autogenous bone (AB) alone led to a significantly higher new bone formation if compared with bovine bone (BB) alone (P = 0.04), while no significant difference was found when the latter was compared with a mixture of AB and BB (P = 0.52). Grafts composed of BB showed significantly greater new bone formation as compared to hydroxyapatite (HA) (P < 0.001) while a mixture of tricalcium phosphate (TCP) and HA achieved better outcomes than BB (P < 0.001). Conclusions: Based on histomorphometric evaluation, AB should still be taken into consideration when the highest possible new bone formation is the primary aim in maxillary sinus surgery. When donor site morbidity is a concern, BB and a mixture of TCP and HA could be considered as predictable, showing promising results. More comparative histologic studies are needed to confirm such results.