title: Considerations for Altering Preparation Designs of Porcelain Inlay/Onlay Restorations for Nonvital Teeth.
abstract: OBJECTIVE
  The aim of this study was to compare all ceramic inlay/onlay survival rates in vital and nonvital teeth having the same cavity design. Filling the pulp chamber with ceramic materials or not was also discussed.
  
  
  METHODS
  Ceramic class II inlays/onlays were made on 11 premolars and 30 molars: 14 vital, 27 endodontically treated. The same tooth preparation design was performed on vital and nonvital teeth: In nonvital teeth the pulp chambers were covered by a glass ionomer cement until the pulpal floor depths were between 2 and 2.5 mm, more likely similar to the vital teeth preparations. In vital teeth, glass ionomer was used as a liner to achieve pulpal floor depths between 2 and 2.5 mm when needed. The restorations were assessed (at baseline, 6 months, 1 and 2 years) according to three criteria: marginal discoloration, marginal integrity, and fracture of teeth/restorations, consistent with United States Public Health Service (USPHS) criteria.
  
  
  RESULTS
  Eight teeth (19%) showed minor marginal discolorations, while three molars (7%) had loss of marginal integrity. These margins were adjusted using rubber polishing cups and were then judged clinically acceptable. From these three molars, one was vital and two were endodontically treated. No fracture of teeth or restorations was observed. Chi square and exact probability tests were used. There was no statistical difference between vital and nonvital teeth (p = 0.719 chi-squared and Fisher) or between premolars and molars (p = 0.564 chi-squared; 1.000, Fisher).
  
  
  CONCLUSIONS
  Within the limitations of this study there was no difference for the same inlay/onlay cavity design between vital and nonvital teeth. In nonvital teeth, it seems that filling the pulp chamber with a ceramic core material is not important. Long-term observation periods are needed to reinforce the clinical behavior outcome.
authors.affiliation: Department of Prosthodontics, Lebanese University, Baabda, Lebanon.
authors.forename: Foudda
authors.initials: F
authors.lastname: Homsy
authors.affiliation: Department of Prosthodontics, Lebanese University, Baabda, Lebanon.
authors.forename: Rita
authors.initials: R
authors.lastname: Eid
authors.affiliation: Department of Prosthodontics, Lebanese University, Baabda, Lebanon.
authors.forename: Wiam
authors.initials: W
authors.lastname: El Ghoul
authors.affiliation: Department of Prosthodontics, Lebanese University, Baabda, Lebanon.
authors.forename: Jose Johann
authors.initials: JJ
authors.lastname: Chidiac
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003776:Dental Porcelain / Q000627:therapeutic use*; D017267:Dental Prosthesis Design; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D005260:Female; D006801:Humans; D007284:Inlays / Q000379:methods; D008297:Male; D008875:Middle Aged; D019553:Tooth, Nonvital / Q000473:pathology / Q000601:surgery*; D055815:Young Adult
chemical_list: D003776:Dental Porcelain
keywords: Cavity design; ceramic; inlay; nonvital; onlay; vital