A Comparative Evaluation of the Tensile Bond Strength of Cement-retained Restorations on Implant Abutments Subjected to Different Surface Treatments: An In vitro Study

Abstract

The longevity of cement-retained implant-supported restorations depends upon a strong and durable bond at the metal/cement interface. Various forms of surface treatments of implant abutments have been shown to enhance the retention of cement-retained restorations. The present study was undertaken to comparatively evaluate the tensile bond strength of metal copings luted onto implant abutments subjected to different surface treatments and determine the most effective surface treatment for long-term retention. Forty acrylic blocks were prepared, each with an implant analogue placed vertically inside the block and straight abutments tightened optimally onto implant analogues. The samples were divided into four Groups (n = 10) according to surface treatment of implant abutments: Group A – no surface treatment, Group B – sandblasting, Group C – metal primer application and Group D – acid etching. Metal copings were luted onto implant abutments, and the tensile force necessary to debond each metal coping was measured using a universal testing machine. Data were summarised in Mean ± Standard deviation. Groups were compared by one factor analysis of variance (ANOVA) and significance of mean difference between the groups was done by Tukey’s honestly significant difference post hoc test after ascertaining normality by Shapiro-Wilk’s test and homogeneity of variance between groups by Levene’s test. A two-tailed (α = 2) P < 0.05 was considered statistically significant. The highest mean tensile bond strength was recorded for Group C (metal primer application), followed by Groups B, D and A, respectively. Amongst the surface treatments used in the study, metal primer application was found to be most effective in improving the retention of cement-retained prostheses.