Influence of root curvature’s initial position on apical deviation occurrence after oscillatory preparation in simulated root canals

Resumo

Introduction and objective: This study aimed to analyze the
influence of root curvature’s initial position on apical deviation
occurrence after oscillatory system preparation. Material and
methods: For this purpose, we used twenty simulated root canals
with 21 mm length and 30 degree angle, which were divided into
two experimental groups according to curvature’s initial position: 8
mm (group A) and 12 mm (group B) short of the canal orifice. The
canals were prepared using crown-down technique, and memory
instrument was size #30. For apical deviation analysis, before and
after preparation, canals were filled with Indian ink and standardly
photographed with the aid of a platform. After that, the images were
manipulated by Adobe Photoshop® software, through superimposing
pre- and post-operative images. Deviation occurrence was measured
1 mm short of working length and at the middle of the curvature
by using the ruler tool. Data were subjected to analysis of variance
(ANOVA) with significance level set at 5%. Results: Although group
B showed a significantly greater deviation mean than group A, no
significant interaction was verified between the analysis site and the
experimental group. Conclusion: According to the present data, it
could be observed that the smaller the curvature radius, the greater
the deviation. Concerning to the analysis site, it could be noted that
the area 1 mm short of working length presented a higher deviation
than the point at the middle of the curvature.