Evaluation the effective of two methods to measure the internal fit of fixed prosthesis (In-vitro study)

Abstract

Background & Aim of study: The methods used to measure the internal fit of fixed prosthesis varied, which is considered one of the most important factors associated with the success of prosthesis, which must be achieved to providing sufficient distance to luting agent to be able to apply prosthesis well, so the purpose of this research to compare the method of the cement replica technique and the method of optical microscopy in the measurement Internal fit of fixed prosthesis.

Materials and Methods: The research sample consisted of 10 metal caps made on 10 stone dies were duplicated from a steel die made by an industrial lathe. Firstly stone dies were covered with die spacer (pico-fit), covering all the axial walls and occlusion surface excluding the apical 1 mm of the preparation, then the metal caps are made. The internal fit was first measured in a cement replica technique, then the metal caps were cemented to the stone dies free die spacer by the glass ionomer and the internal gap was measured by the BX41 OLYMPUS optical microscope magnifying ×10. Data was analyzed using paired t-test analysis at (α=0.05) significance level.

Results: the result of this study showed statistically significant differences between the two methods at 95% confidence level (p<0.05), The internal gap value of the group in which the optical microscope method was used was significantly higher than the group in which the cement replica technique method was used.

Conclusions: Among the limitation of this study we conclude that the optical microscope method is the most accurate and reliable in measuring the internal fit of fixed restorations as it represents the clinical reality.