Avaliação do efeito da dimensão de fresagem no torque de inserção de implantes e na osseointegração inicial: estudo experimental em cães

Abstract

Primary stability has been regarded as a key factor to assure uneventful osseointegration of dental implants. Such stability is often achieved by placing implants in undersized drilled bone. This study evaluated the effect of drilling dimensions in insertion torque and early implant integration in a beagle dog model. Six beagle dogs were acquired and subjected to bilateral surgeries in the radius 1 and 3 weeks prior to euthanization. During surgery, three implants of 4 mm in diameter by 10 mm length were placed in bone sites drilled to 3.2mm, 3.5mm and 3.8mm in diameter. The insertion torque value was recorded for all samples. Following sacrifice, the implants in bone were non decalcified processed and morphologically and morphometrically (bone-to-implant contact (BIC), and bone area fraction occupancy (BAFO) evaluated. Statistical analyses were performed by Kruskal-Wallis followed by Dunn s post hoc for multiple comparisons at 95% level of significance. The insertion torque values obtained were inversely proportional to the drilling dimension, where a significant difference was detected between the 3.2mm and 3.8mm groups (p=0.003). Despite a significant increase in BIC over time in vivo for all groups (p=0.007), no effect of drilling dimension was observed. Additionally no effect of drilling dimension and time was observed for the BAFO parameter (p=0.31). Initial healing pathways differed between implants placed in bone drilled to different dimensions. While different degrees of torque were observed due to drilling dimensions and these resulted in different healing patterns, no differences in histometrically evaluated parameters were observed.