A four to six years follow-up of indirect resin composite inlays/onlays

Abstract

The objective of this clinical survival study was to evaluate the performance of indirect resin composite inlays and onlays. Patients were recruited among the dental school clientele needing posterior approximal restorations and preferring esthetic restorations. Two clinical teachers and 6 trained students under supervision carried out the preparations, made impressions, and prepared stone casts. Inlays/onlays from Tetric ® , Z100 ® , or Maxxim ® were light-cured and transferred to a light oven for secondary curing. At the 4-6 year recall, the inlays/onlays were evaluated using slightly modified US Public Health Service criteria, bitewing radiographs, and plastic dies based on replica impressions. All 25 treated patients with a total of 64 inlays/onlays presented for the assessment. The right-censored observation periods ranged from 48 to 75 months, with a mean of 59. With the exception of three failed inlays/onlays scored as 'D' (2 fractures, 1 caries), i.e. 5%, the majority were classified as successful. This was based on 43 'A' (optimal) and 18 'B' (acceptable) ratings, each of which represented the lowest rating for each individual restoration. The major reason for 'B' ratings was imperfect anatomical form, mostly absence of proximal contacts. The present clinical trial demonstrated that inlays/onlays made from Tetric, Z100, and Maxxim performed equally well over the 5-year period. Within the limits of this study it is concluded that the resin composite inlay/onlay technique should be considered as an alternative to direct fillings in the approximal posterior region.