Avaliação da Alteração Dimensional em Modelos de Gesso Tipo IV Obtidos a Partir de Moldes de Silicona de Adição após Desinfecção por Imersão em Glutaraldeído a 2%

Abstract

RESUMO DESCRIPTORS DESCRITORESGesso dentário; Materiais para moldagem odontológica; Glutaraldeído. Calcium Sulfate; Dental impression materials; Glutaral.Evaluation of the Dimensional Alterations in Type IV Plaster Models Obtained from Addition Silicone Impressions after Disinfection by Immersion in 2% GlutaraldehydeObjective: To determine under light microscopy the dimensional alterations produced in type IV plaster models obtained from addition silicone impressions disinfected by immersion in 2% glutaraldehyde. Method: Four groups were formed from a rectangular metallic matrix containing two graded cylinders for measurement of the dimensional alterations. For each group, 10 impressions were taken using individual acrylic resin trays and an addition silicone impression material, varying the disinfection process and plaster pouring. Group A: addition silicone impressions disinfected by immersion in 2% glutaraldehyde and poured with type IV plaster using a vacuum mixing device; Group B: non-disinfected addition silicone impressions poured with type IV plaster by hand mixing; Group C: addition silicone impressions disinfected by immersion in 2% glutaraldehyde poured with type IV plaster by hand mixing; Group D: non-disinfected addition silicone impressions poured with type IV plaster using a vacuum mixing device. The plaster models were examined under light microscopy at 100-fold magnification for measurement of the distances between the previously demarcated points. The obtained data were compared among the groups and the groups were compared to the original matrix. Results:No group differed significantly from the original matrix, according to the non-parametric Kruskal-Wallis test. Conclusion: Disinfection by immersion in 2% glutaraldehyde did not produce significant dimensional alterations when compared to the original matrix, being therefore indicated for the clinical practice. Plaster pouring by vacuum mixing exhibited better results than the mechanical hand mixing method.