A new dental casting technique for production of void-free dental models

Abstract

PurposeAn essential of successful dental prosthesis is dental models. Voids present in dentalmodels decreases accuracy and strength. This study investigates void formation inmodels fabricated by a new technique. The technique described in the study wasbased upon increasing soaking time of gypsum powder in water.Materials and MethodsVoids in hand mixed, hand mixed after a soaking time of 1.5 minutes and vacuummixed samples were examined. The voids were counted via a stereomicroscope anddiameters of voids were recorded in 2 categories (0.01-0.05mm, 0.051-0.1mm). Theamounts of voids were compared between the samples prepared with 3 methods.ResultsThe samples prepared by conventional hand mixing method had the highest totalnumber of voids and smaller voids. There was no significant difference betweenthe amount of voids in the samples prepared by soaking powder in water and bymixing under vacuum.ConclusionSoaking gypsum powder in water for 1.5 minutes before mixing may be analternative to mixing gypsum under vacuum to avoid void formation in dentalmodels