title: IPS Empress inlays and onlays after four years--a clinical study.
abstract: OBJECTIVE
  Ceramic inlays are used as esthetic alternatives to amalgam and other metallic materials for the restoration of badly damaged teeth. However, only limited clinical data are available regarding adhesive inlays and onlays with proximal margins located in dentine. In a prospective, controlled clinical study, the performance of IPS Empress inlays and onlays with cuspal replacements and margins below the amelocemental junction was examined.
  
  
  METHODS
  Ninety-six IPS Empress fillings were placed in 34 patients by six clinicians. The restorations were luted with four different composite systems. The dentin bonding system Syntac Classic was used in addition to the acid-etch-technique. At baseline and after 6 months, one, two and four years after placement the restorations were assessed by two calibrated investigators using modified USPHS codes and criteria. A representative sample of the restorations was investigated by scanning electron microscopy to evaluate wear.
  
  
  RESULTS
  Seven of the 96 restorations investigated had to be replaced (failure rate 7%; Kaplan-Meier). Four inlays had suffered cohesive bulk fractures and three teeth required endodontic treatment. After four years in clinical service, significant deterioration (Friedman 2-way Anova; p < 0.05) was found to have occurred in the marginal adaptation of the remaining restorations. 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.
  
  
  CONCLUSIONS
  After four years, extensive IPS Empress inlays and onlays bonded with the dentin bonding system Syntac Classic were found to have a 7% failure rate with 79% of the remaining restorations having marginal deficiencies.
authors.affiliation: University of Erlangen-Nuremberg, Germany. kraemer@dent.uni-erlangen.de
authors.forename: N
authors.initials: N
authors.lastname: Krämer
authors.forename: R
authors.initials: R
authors.lastname: Frankenberger
authors.forename: M
authors.initials: M
authors.lastname: Pelka
authors.forename: A
authors.initials: A
authors.lastname: Petschelt
mesh_terms: D000328:Adult; D000538:Aluminum Silicates; D001641:Bicuspid; D001840:Dental Bonding; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear; D017220:Dentin-Bonding Agents; D005260:Female; D006801:Humans; D007284:Inlays; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D008963:Molar; D011446:Prospective Studies; D019279:Resin Cements; D019233:Retreatment; D018709:Statistics, Nonparametric; D016019:Survival Analysis
chemical_list: D000538:Aluminum Silicates; D017220:Dentin-Bonding Agents; C075815:IPS-Empress ceramic; D019279:Resin Cements; C078484:Syntac dentine adhesive; D003776:Dental Porcelain