Marginal integrity of all-ceramic crowns cemented with different luting materials

Objectives: The aim of this study was to evaluate the marginal integrity of all-ceramic crowns cemented with three different luting materials after fatigue test. Methods: Twenty-four IPS-Empress II all-ceramic crowns were cemented onto natural molars. An adhesive composite resin luting system, a compomer cement and a zinc phosphate cement were used for 8 specimens each. The specimens were fatigued with 3,500 thermal cycles. An impression-replica technique and scanning electron microscopy were used for evaluation of the integrity and superficial quality of the marginal areas. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. Results: The marginal integrity was higher than 95% for the adhesive composite resin luting system cemented all-ceramic crowns before and after fatigue test. The marginal integrity was between 16-19% for the compomer cement and 5% for the zinc phosphate cement. High significant difference of marginal integrity was found between the groups (P < 0.001). The defects in the adhesive composite resin luting system were significantly less than those in other two groups (P < 0.05). Conclusions: The adhesive composite resin luting system showed excellent marginal integrity and superficial quality when used for all-ceramic crowns.