BOVINE HYDROXYAPATITE FOR MAXILLARY SINUS AUGMENTATION - ANALYSIS OF INTERFACIAL BOND STRENGTH OF DENTAL IMPLANTS USING PULL-OUT TESTS

This study examines the effect of sinus lift surgery using bovine hydr oxyapatite on the bone anchorage of titanium plasma flame-spray-coated cylindrical implants. A total of 54 implants were placed in the later al bony antral walls of 27 mountain sheep. Host site augmentation was done simultaneously using bovine hydroxyapatite and autogenous cancell ous bone from the iliac crest in 18 sinuses each. The bone walls of th e remaining 18 sinuses received no augmentation. Pull-out tests were c arried out at 12, 16, and 26 weeks. revealing a significant influence of the implants' residence time on Full-out strength (P=0.004). The im plants of the non-augmented group and those of the group augmented usi ng cancellous bone showed a linear increase in pull-out strength to 16 9.8 N and 523.7 N, respectively, until the 26th week. The implants of the group augmented with bovine hydroxyapatite exhibited the highest i nitial pull-out strength (325.1 N) that further increased to 521.8 N u ntil the 26th week. All in all, this group showed a significantly grea ter pull-out strength than did the negative control group (P=0.03).