Comparison of SLA(®) or SLActive(®) implants placed in the maxillary sinus with or without synthetic bone graft materials - an animal study in sheep

Abstract

AIMS: To assess the influence of an activated implant surface and a synthetic graft material in the maxillary sinus in combination with sinus floor elevation on bone-to-implant contact (BIC) as compared to implants with conventional surfaces. MATERIAL AND METHODS: In 16 sheep, sinus bone augmentation was performed using a synthetic bone graft material according to the methods described by Haas et al (Clinical Oral Implants Research, 9, 1998, 107; Clinical Oral Implants Research, 13, 2002, 396). Another 16 sheep received a sinus floor elevation procedure without graft material. Using a paired design, in one sinus of each animal, a conventional implant was placed, whereas an implant with activated surface was placed in the other. Eight animals of each group were sacrificed at 12 weeks and the others at 26 weeks after surgery. Histological analysis was performed to analyse BIC. Results were statistically compared at a significance level of P < 0.05. RESULTS: After 12 weeks, the BIC for conventional and activated implants with or without graft showed comparable results, with mean values of 14.8%, 16.5%, 21.5% and 20.1% (P > 0.05). For ungrafted sinuses after 26 weeks, no increase in BIC was recorded (12.1% conventional surface, 15.8% activated surface; P > 0.05). In grafted sinuses after 26 weeks, mean values increased to 28.7% for conventional and 34.1% for activated implants (P = 0.014; P = 0.015). However, only BIC of the latter was statistically significantly higher compared with ungrafted sinuses (P = 0.038). CONCLUSION: After 12 weeks of healing, neither grafting nor implant type seemed to influence BIC. Use of an activated implant surface did not increase BIC when compared with a conventional implant. The synthetic graft seemed to improve BIC values after 26 weeks.