title: Dentist-time expenditure for two different adhesive all-ceramic systems.
abstract: OBJECTIVE
  The purpose of this clinical investigation was to compare a chair-side adhesive all-ceramic system to a laboratory processed adhesive all-ceramic system with respect to quality and time expenditure for the dentist.
  
  
  METHODS
  The same dentist treated 10 patients, who were each to receive two large posterior single tooth restorations of similar location and extent. One restoration was made in the laboratory by using the IPS Empress system [LAB], the other one was done chair-side by utilizing the Cerec system [CHAIR]. The time expenditure was measured for [LAB] and [CHAIR] and compared by the Wilcoxon signed rank test. The restorations were also evaluated according to the USPHS criteria.
  
  
  RESULTS
  The mean time expenditure for the dentist with low-level assistance was 111:03 min [S.D.+/-24:09 min] for [LAB] and 115:31 min [S.D.+/-15:54 min] for [CHAIR]. Time expenditure with medium level assistance for the operator was 100:53 min [S.D.+/-23:59] for [LAB] and 105:50 [S.D.+/-15:28] for [CHAIR]. Assuming a high level of assistance, the mean time values were 53:11 min [S.D.+/-14:29] for [LAB] and 54:29 min [S.D.+/-09:21] for [CHAIR]. The baseline investigation according to the modified USPHS criteria did not reveal any differences between [CHAIR] and [LAB].
  
  
  CONCLUSIONS
  There were no statistical significant differences with respect to time expenditure or quality between [LAB] and [CHAIR] in this study.
authors.affiliation: Department of Prosthetic Dentistry of the University of Erlangen-Nuremberg, Glueckstrasse 11, D-91054 Erlangen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wurbs
authors.forename: James F
authors.initials: JF
authors.lastname: Simon
authors.forename: Markus
authors.initials: M
authors.lastname: Troeltzsch
authors.forename: Thomas
authors.initials: T
authors.lastname: Denekas
authors.forename: Manfred
authors.initials: M
authors.lastname: Wichmann
authors.forename: Sven
authors.initials: S
authors.lastname: Reich
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002484:Cementation; D002516:Ceramics / Q000737:chemistry; D003116:Color; D017076:Computer-Aided Design; D001840:Dental Bonding / Q000379:methods*; D003737:Dental Cavity Preparation / Q000379:methods; D003761:Dental Impression Technique; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain / Q000737:chemistry; D005260:Female; D006801:Humans; D007284:Inlays / Q000379:methods* / Q000592:standards; D007754:Laboratories, Dental; D008297:Male; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; C075815:IPS-Empress ceramic; D003776:Dental Porcelain; C074543:Cerec