The influence of tooth surface roughness on retention of complete cast crowns using glass ionomer cement

Abstract

Background: The purpose of this in-vitro study was to evaluate the effect of tooth surface roughness on retention of complete cast crowns cemented with glass ionomer cement. Materials and Methods: Forty sound human maxillary first premolars were used in this study. Each tooth was embedded in individual acrylic block. Then the teeth received complete cast crown preparation with diamond burs (group I), diamond burs and treated with air flow (group II), tungsten carbide burs (group III), and tungsten carbide burs with air flow treatment (group IV). Complete cast crowns were fabricated for all teeth and cemented with glass ionomer cement. The cemented crowns were stored in normal saline solution for 24 hours, and then separated in tension by the use of an Instron testing machine. Results: The results showed that crowns cemented on teeth prepared with carbide burs and air-flow treatment exhibited the highest mean tensile stresses followed by crowns cemented on teeth prepared with carbide burs only, then crowns cemented on teeth prepared by diamond burs and air-flow treatment, while crowns cemented on teeth prepared with diamonds bur only exhibited the lowest mean tensile stresses. Conclusions: Glass ionomer cement provided greater retention for cast crowns on smooth than on rough surfaces.