title: Influence of different base thicknesses on maxillary complete denture processing: linear and angular graphic analysis on the movement of artificial teeth.
abstract: OBJECTIVE
  The purpose of this study was to compare the dental movement that occurs during the processing of maxillary complete dentures with 3 different base thicknesses, using 2 investment methods, and microwave polymerization.
  
  
  METHODS
  A sample of 42 denture models was randomly divided into 6 groups (n = 7), with base thicknesses of 1.25, 2.50, and 3.75 mm and gypsum or silicone flask investment. Points were demarcated on the distal surface of the second molars and on the back of the gypsum cast at the alveolar ridge level to allow linear and angular measurement using AutoCAD software. The data were subjected to analysis of variance with double factor, Tukey test and Fisher (post hoc).
  
  
  RESULTS
  Angular analysis of the varying methods and their interactions generated a statistical difference (P = 0.023) when the magnitudes of molar inclination were compared. Tooth movement was greater for thin-based prostheses, 1.25 mm (-0.234), versus thick 3.75 mm (0.2395), with antagonistic behavior. Prosthesis investment with silicone (0.053) showed greater vertical change compared with the gypsum investment (0.032). There was a difference between the point of analysis, demonstrating that the changes were not symmetric.
  
  
  CONCLUSIONS
  All groups evaluated showed change in the position of artificial teeth after processing. The complete denture with a thin base (1.25 mm) and silicone investment showed the worst results, whereas intermediate thickness (2.50 mm) was demonstrated to be ideal for the denture base.
authors.affiliation: Department of Dental Materials and Prosthodontics, School of Dentistry at Araçatuba, UNESP-Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: José Vitor Quinelli
authors.initials: JV
authors.lastname: Mazaro
authors.forename: Humberto
authors.initials: H
authors.lastname: Gennari Filho
authors.forename: Eduardo
authors.initials: E
authors.lastname: Vedovatto
authors.forename: Andressa Paschoal
authors.initials: AP
authors.lastname: Amoroso
authors.forename: Eduardo Piza
authors.initials: EP
authors.lastname: Pellizzer
authors.forename: Adriana Cristina
authors.initials: AC
authors.lastname: Zavanelli
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D017076:Computer-Aided Design; D003735:Dental Casting Technique; D003764:Dental Materials; D003819:Denture Bases; D003779:Denture Design; D003827:Denture, Complete, Upper; D006801:Humans; D008872:Microwaves; D014087:Tooth Movement Techniques; D014093:Tooth, Artificial
chemical_list: D000180:Acrylic Resins; D003764:Dental Materials