Immunoexpression of Cbfa-1/Runx2 and VEGF in sinus lift procedures using bone substitutes in rabbits.

OBJECTIVES: To analyze and compare the expression of core binding factor-1 (Cbfa-1)/Runx2 and vascular endothelium growth factor (VEGF) in sinus lift procedures using bovine hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP).

MATERIAL AND METHODS: Twenty-four male rabbits that had undergone bilateral sinus lift procedures were divided into three groups, according to the sinus filling material: Group 1: autogenous bone graft; Group 2: bovine HA; and Group 3: beta-TCP. All groups were sacrificed after 7, 14, 30 and 60 days, for microscopic, histomorphometry and immunohistochemistry analysis.

RESULTS: Microscopic analysis showed a similar bone repair pattern between the tested groups. New bone formation, soft and medular tissue, remaining material or particulate bone graft area were obtained by histomorphometric analysis. After 14 days, statistically significant differences in new bone formation were found between Group 1 (27.76+/-7.8) and Groups 2 (14.22+/-3.2) and 3 (11.1+/-7.7). After 30 days, statistically significant differences (P<0.05) were detected in bone formation between Groups 1 (31.39+/-36.5) and 2 (14.13+/-3.2). The last period showed improved bone formation in Group 2. Also, Group 2 showed higher Cbfa-1/Runx2 immunoexpression when compared with Group 3. No remarkable differences were observed in VEGF immunoexpression among groups.

CONCLUSION: Taken together, both biomaterials allowed bone tissue growth in a conductive pattern and did not interfere with bone remodeling in the late period, with a slight improvement in bone tissue formation when using HA, confirmed by marked expression of Cbfa-1 at initial periods.