Influência da profundidade óssea de implantes extra curtos na distribuição de tensão periimplantar; um estudo ex vivo

Abstract

The study evaluated extra short biomechanical implants installed in two bony depths with different implant crown (C/I) proportions. Segmented bovine ribs were used and divided in 6 groups according to the factors of study. the depth of installation of the implant (bone level and 2mm) and the C/I (1:1, 2:1 and 3:1). Each bone fragment received an extra short implant (6x5mm) and a prosthetic crown according to the established C/I. Extensometers were bonded to the cortical, vestibular, lingual, distal and mesial surfaces to assess bone deformation. The samples were adapted to a fatigue simulator and a 120 N load was applied. The data were analyzed by a two-way ANOVA and multiple comparisons by the test of Tukey (5%). The analysis indicated that C/I proportion (lingual F = 26.758 and p=0.000; distal F = 6.383 and p=0.006; buccal F=136.720 and p=0.000) and implant the position (lingual F = 74.560 and p=0.000; distal F = 121.622 and p=0.006; buccal F=46.206 and p=0.000) influenced the values of deformations, except for the mesial surface (crown/implant proportion F = 2.197 and p=0.133 and depth of insertion F = 2.572 and p=0.122).The factor proportion C/I demonstrated a tendency of increase of deformations with increase of the relation C/I being more obvious in the distal area distal and at bone level, proportion 1/1 (0.076±0.03 mm); 2/1 (0.097±0.04 µstrain) and to proportion 3/1 (0.100±0.04 µstrain). This factor was observed, also, in the implants infra-bone with differences among the proportions 1/1 (0.144±0.01 µstrain) and 2/1 (0.253±0.18 µstrain) and 3/1 (0.263±0.23 µstrain) that not differentiate among one another. In front of the results we can conclude that the increase of the proportion C/I suffers less influence when the implant is installed infra bone.