An in vitro assessment of optimizing implant positions in bilateral distal extension implant-assisted removable partial dentures: A microstress analysis.

Abstract

The aim of this study was to analyze and compare the stress distribution on dental implants in various positions when used with implant-assisted removable partial dentures. This was an in vitro study. A model representing a mandibular bilateral partially edentulous condition, with missing premolars and molars, was fabricated using epoxy resin. Two implants of similar diameter measuring 4.0 mm × 10 mm (Dentium, Korea) were inserted in the second molar and the second premolar region on either side of the model for comparing the biomechanical effect of various implant locations. Two types of loads 100N and 125N were applied vertically using universal testing machines in the premolar and molar regions. The loads on the implants beneath the cast partial denture were measured by physical stress analysis using a microstrain gauge. A comparison of maximum stress observed at the premolar versus molar regions due to the application of the 100N and 125N loads was done using the Mann-Whitney U-test. In physical stress analysis, obtained results were statistically analyzed, and the result was statistically not significant (P = 0.435 at 100N and P = 0.718 at 125N) in positional changes of implant. In the current study, the statistical analysis of physical stress revealed no significant differences in stress values between the loadings at the premolar and molar regions. This suggests that the implant can be placed in either the premolar or molar region based on the availability of bone without affecting stress distribution.