Redução da força de retenção e abertura de grampos a barra em "I" de Roach e sua correlação

Abstract

The purpose of this research was to determine the retention drop of I-bar clasps, their possible opening during mechanical cycling and their correlation. Two Co-Cr alloys were used and the design of clasps were: short-thin; short-thick; long-thin; long-thick. Clasps were also partially covered or not with resin. Measurements were made at the initial stage and after 20 thousand cycles. The results led to the following conclusions: the alloys presented similar retention drop; opening of the several types of clasps were similar, but retention drop was minor on long-thin clasp and major on short-thick ones; resin did not influence the opening of clasps but increased retention drop; correlation between retention drop and opening of clasps was not significant.