title: Five-year results of a prospective randomised controlled clinical trial of posterior computer-aided design-computer-aided manufacturing ZrSiO4 -ceramic crowns.
abstract: The aim of this prospective randomised controlled clinical trial was to evaluate the clinical outcome of shrinkage-free ZrSiO4 -ceramic full-coverage crowns on premolars and molars in comparison with conventional gold crowns over a 5-year period. Two hundred and twenty-three patients were included and randomly divided into two treatment groups. One hundred and twenty-three patients were restored with 123 ZrSiO4 -ceramic crowns, and 100 patients received 100 gold crowns, which served as the control. All crowns were conventionally cemented with glass-ionomer cement. After an observation period of 6, 12, 24, 36, 48 and 60 months, the survival probability (Kaplan-Meier) for the shrinkage-free ZrSiO4 -ceramic crowns was 98·3%, 92·0%, 84·7%, 79% and 73·2% and for the gold crowns, 99%, 97·9%, 95·7%, 94·6% and 92·3%, respectively. The difference between the test and control group was statistically significant (P = 0·0027). The gold crowns showed a better marginal integrity with less marginal discoloration than the ceramic crowns. The most common failure in the ceramic crown group was fracture of the crown. The 60-month results of this prospective randomised controlled clinical trial suggest that the use of these shrinkage-free ZrSiO4 -ceramic crowns in posterior tooth restorations cannot be recommended.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University Medical Center Freiburg, Freiburg, Germany. npassia@proth.uni-kiel.de
authors.forename: N
authors.initials: N
authors.lastname: Passia
authors.forename: S
authors.initials: S
authors.lastname: Stampf
authors.forename: J R
authors.initials: JR
authors.lastname: Strub
mesh_terms: D000328:Adult; D000368:Aged; D001641:Bicuspid / Q000601:surgery; D017076:Computer-Aided Design; D003442:Crowns / Q000009:adverse effects*; D003776:Dental Porcelain / Q000627:therapeutic use*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D005260:Female; D006046:Gold / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar / Q000601:surgery; D011446:Prospective Studies; D017640:Silicates / Q000627:therapeutic use*; D014076:Tooth Diseases / Q000534:rehabilitation*; D016896:Treatment Outcome; D055815:Young Adult; D015040:Zirconium / Q000627:therapeutic use*
chemical_list: D017640:Silicates; D003776:Dental Porcelain; C003784:zircon; D006046:Gold; D015040:Zirconium
keywords: ZrSiO4-ceramic; computer-aided design-computer-aided manufacturing; controlled clinical trial; posterior crowns; survival rates