Evaluation of Effect of Surface Treatment of Intaglio Surface on Retention of Complete Cast Crowns Cemented with Different Cements: An In vitro Study

Abstract

Introduction: Recently, several adhesive primers for base metals have become commercially available. The effect of metal primers on noble alloys has been studied several times and proved to be efficacious but there is insubstantial information about their effect on base metal alloys. Hence, the purpose of this study is to evaluate the effect of surface treatment (sandblasting with alumina oxide particles and metal primer) on retention of complete cast crowns luted with different cements. Aim: To compare and evaluate the effect of surface treatments of intaglio surface on retention of complete cast crowns cemented with different luting cements. Materials and Methods: In this in-vitro experimental study a total of 50 extracted human sound premolar teeth were prepared to receive cast metal crowns made of cobalt-chromium alloy. Teeth were mounted in an index using autopolymerising acrylic resin; crown preparations were made with a high-speed hand piece stabilised by using a k-9 crown installation machine and 6° taper was achieved for all preparations. Occluso-cervical dimension of the teeth was standardised at 4 mm for all the samples. Based on type of luting cement, the teeth were divided into five groups: glass ionomer cement (10); resin modified glass ionomer cement (10); resin-modified glass ionomer cement with surface treatment (10); resin cement (10); and resin cement with surface treatment (10). After surface treatment and cementation procedures, samples were stored in storing media and then subjected to tensile loading with universal testing machine (TU-400 Batch no-99/01, Fine Spavy, INDIA) to separate crowns from the tooth. ANOVA test followed by Tukey’s Honest Significant Difference (HSD) post-hoc test were employed in the analysis of data. SPSS 17.0 statistical software was used to analyse the data. Results: Among cements tested in the study, resin cement with surface treatment (7.61±0.78) Mpa had the highest tensile bond strength, while glass ionomer had the lowest tensile bond strength (3.78±0.65) Mpa. Significant improvement was observed in tensile bond strength after surface treatment with both the cements (resin modified glass ionomer and resin cement) with p<0.001. Conclusion: The study reasonably concluded that the type of surface treatment may have a significant effect on retentive strength of crowns. Combination of sandblasting and metal primer can be considered to improve the bond strength of luting agents.

Keywords

• dental alloys
• metal primer
• resin based cements
• retentive strength
• sandblasting