IPS Empress inlays and onlays after four years - a clinical study

Objective: Ceramic inlays are used as esthetic alternatives to amalgam and other metallic materials for the restoration of badly damaged teeth. Howeve r, only limited clinical data are available regarding adhesive inlays and o nlays with proximal margins located in dentine. In a prospective, controlle d clinical study, the performance of IFS Empress inlays and onlays with cus pal replacements and margins below the amelocemental junction was examined, Materials and methods: Ninety-six IFS Empress fillings were placed in 34 p atients by six clinicians. The restorations were luted with four different composite systems. The dentin bonding system Syntac Classic was used in add ition to the acid-etch-technique, At baseline and after 6 months, one, two and four years after placement the restorations were assessed by two calibr ated investigators using modified USPHS codes and criteria. A representativ e sample of the restorations was investigated by scanning electron microsco py to evaluate wear. Results: Seven of the 96 restorations investigated had to be replaced (fail ure rate 7%; Kaplan-Meier). Four inlays had suffered cohesive bulk fracture s and three teeth required endodontic treatment. After four years in clinic al service, significant deterioration (Friedman 2-way Anova; p < 0.05) was found to have occurred in the marginal adaptation of the remaining restorat ions. Seventy-nine percent of the surviving restorations exhibited marginal deficiencies, independent of the luting composite. Neither the absence of enamel margins, nor cuspal replacement significantly affected the adhesion or marginal quality of the restorations. Conclusion: After four years, exte nsive IPS Empress inlays and onlays bonded with the dentin bonding system S yntac Classic were found to have a 7% failure rate with 79% of the remainin g restorations having marginal deficiencies. (C) 1999 Elsevier Science Ltd, All rights reserved.