6-YEAR CLINICAL-EVALUATION OF FIRED CERAMIC INLAYS

The purpose of the present study was to evaluate the quality of fired ceramic inlay restorations consisting of a feldspathic porcelain syste m (G-Cera Cosmotech II) after 6 years in vivo. A total of 49 fired cer amic inlays (for 27 premolars and 22 molars: class 1 in 11 teeth, clas s 2 in 36 teeth, and onlays in two teeth) were placed in 29 patients, and all restorations were evaluated at the time of placement, at 6 mon ths, and 1, 2, 4, and 6 years after placement using modified USPHS cri teria. Replicas made of the restorations were observed using a scannin g electron microscope (SEM) to assess the state of the marginal area a nd wear of the restoration. Favorable color match was noted, and no bu lk fracture, tooth fracture, or missing restorations were detected. Lo ngevity was observed in 92% of the fired ceramic inlay restorations at 6 years (Kaplan-Meier method); however, marginal fracture was detecte d in six restorations (13%) and marginal discoloration in 11 (23%). SE M evaluation disclosed marginal microfracture in 49% of the restoratio ns, wear in 19%, and wear of resin cement along margins in 36% at 6 ye ars. No significant difference was observed in the incidence of each o f these three characteristics between molars and premolars. This longi tudinal 6-year clinical observation suggested that fired ceramic inlay restorations made by the G-Cera Cosmotech II system are aesthetic, du rable, and clinically acceptable. Further follow-up is needed for the restorations showing marginal degradation and fracture from a microsco pic and macroscopic perspective.