Teeth displacement of lower implant-retained complete dentures under influence of microwave flask types

Abstract

The aim of this study is to evaluate the movement of artificial teeth in lower protocols processed with two types of microwave flasks (traditional and experimental HH with teeth in occlusion). One model mounted on a standard semi-adjustable articulator will be used to fabricate metal infrastructures in Co-Cr alloy. The standard mounting teeth protocol will be made on the infrastructure, articulated with a conventional upper denture. From this assembly will be made 20 prostheses waxed. Metal pins are placed in the teeth as a reference for the measurements pre-processing and post-processing of the prosthesis, being: incisal edge of the upper and lower central incisors (I), the buccal cusp of the first premolars and the lower entrance (PM), cusps mesiobucal the upper second molars and mesiobuccal of lower (M). Transverse distances II (incisor to incisor), AM-PM (premolar to premolar) and MM (molar to molar); anteroposterior IE ME (left incisor to left molar) and ID-MD (right incisor the right molar) and vertical II, PP, MM, IE and ID-ME MD will be measured with linear optical microscope STM (Olympus, Tokyo, Japan) with an accuracy of 0.0005 mm. The dentures will be randomized to polymerization in microwave oven in groups (n = 10): G1 - With conventional flask and G2 - With flask experimental HH (teeth in occlusion). The acrylic resin in plastic stage will be inserted in plastic flasks and processed in a microwave oven with 1400 W power (20 minutes at 20% power and 5 minutes at 60%). For the evaluation of tooth movement will be considered a change of occlusal contacts and the vertical dimension along with the changes in the distances pre-processing and post-processing of the prosthesis. The difference between the initial values and then polymerization is considered to drive the teeth. The results will be submitted to analysis of variance (ANOVA) and the differences analyzed by Tukey test (5%).