title: The efficacy of glass-ceramic onlays in the restoration of morphologically compromised and endodontically treated molars.
abstract: OBJECTIVE
  This study evaluated the 4-year clinical performance of IPS Empress II ceramic onlay restorations on extensively restored, endodontically treated molars.
  
  
  METHODS
  A sample of 53 morphologically compromised and endodontically treated molar teeth were restored with IPS Empress II ceramic onlays cemented with a dual cured luting composite. The molars were evaluated by two experienced clinicians in accordance with the modified United States Public Health Service criteria at baseline and 6-month recalls up to a 4-year observation period. The analyses were carried out using the Wilcoxon signed-rank test and the Kaplan-Meier product limit method.
  
  
  RESULTS
  Four failures were noted. Two onlays debonded; one was reinserted and reluted while the other resulted in lost coronal hard tissue and was restored with a fiber reinforced post-and-core system followed by a full ceramic crown restoration. The third failure resulted from secondary caries and fracture of the remaining enamel and was restored with a full ceramic crown. The fourth failure was extracted. None of the onlays exhibited wear, fracture of antagonist teeth, or dimensional change at proximal contacts.
  
  
  CONCLUSIONS
  Within the limitations of this study's design and short 4-year observation period, IPS Empress II ceramic onlay restorations demonstrated promising results with a 92.5% success rate.
authors.affiliation: Dedpartment of Operative Dentistry, Marmara University Faculty of Dentistry, Istanbul, Turkiye.
authors.forename: Gurol
authors.initials: G
authors.lastname: Ozyoney
authors.forename: Funda
authors.initials: F
authors.lastname: Yan Koğlu
authors.forename: Dilek
authors.initials: D
authors.lastname: Tağtekin
authors.forename: Osman
authors.initials: O
authors.lastname: Hayran
mesh_terms: D000293:Adolescent; D000328:Adult; D002516:Ceramics; D003776:Dental Porcelain; D019232:Dental Restoration Failure; D006801:Humans; D007284:Inlays; D053208:Kaplan-Meier Estimate; D008963:Molar; D018709:Statistics, Nonparametric; D019553:Tooth, Nonvital / Q000628:therapy*; D014421:Turkey; D055815:Young Adult
chemical_list: D003776:Dental Porcelain; C023506:Glass ceramics