Alteração dimensional da base de protese total superior e inferior, sob influencia da inclusão em mufla dupla / Dimensional change of the maxillary and mandibular denture base under influence of double flask

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The purpose of this work was to study the use of flask closure (conventional metallic flask closure nº5,5 and double SR flask closure.), regarding the adaptation of the prothesis´base (immediate and after six hours) in the upper total prothesis base and also the inferior total prothesis base adaptation. Both prothesis were made of acrylic resin activated by temperature (Classic®). 80 gypsum models were manufactured with wax base randomly distributed in 8 groups (n=10), according to the type of metallic flask closure used and the time that the prothesis remained under pressure (immediate or after six hours). The resin was proportionate and manipulated according to the manufacturer instructions and it was put under pressure in the plastic phase, starting with 850 Kgf until 1250 Kgf utilizing the hydraulic press of workbench. The bases were manufactured and polymerized in water cycle at 74°C for 9 hours. After they reached room temperature, the bases were removed, finished, and replaced in its respective models using cianocrilato adhesive on the base. The models were divided into three sections, corresponding to distal of canines, mesial of first molars and posterior palate region. In each model, the superior and lower maladjustment between the gypsum model and the resin base was verified in the reference points mention above; Superior model: bottom of vestibular sulcus (right and left sides), alveolar crest (right and left sides) and average line of the palate. Lower model: bottom of vestibular sulcus (right and left sides), crest of the edge alveolar crest (right and left sides) and bottom of lingual sulcus (right and left sides). In each section, the maladjustment between the model and resin base was verified with an Olympus comparative linear microscope, with 0,0005mm accuracy. The data were collected and submitted to analysis of variance and to the test of Tukey (5%). The test results demonstrated a significant statistical difference between the sections, where section A showed the best result, C the worst, and B showed an intermediate value, for the lower and upper bases of the prothesis. In the base of the upper prosthesis, the time that the material was under pressure in each region and type of flask closure showed statistical difference, except in region A, for the simple flask closure. In the comparison between types of flask closure for each region in the immediate time showed significant statistical difference for all the regions. There was no statistical difference during the time the material was under pressure (6 hours) for all comparisons. When the types of flask closure were compared regarding region types for each time the lower base was under pressure, the immediate time showed statistical difference in all the regions. There was no statistical difference between the regions and types of flask closure after a period of six hours

ASSUNTO(S)

resinas acrilicas adaptation acrylic resins adaptação

ACESSO AO ARTIGO

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