title: Reliability and mode of failure of bonded monolithic and multilayer ceramics.
abstract: To evaluate the reliability of monolithic and multilayer ceramic structures used in the CAD-on technique (Ivoclar), and the mode of failure produced in ceramic structures bonded to a dentin analog material (NEMA-G10).
  
  
  
  Ceramic specimens were fabricated as follows (n=30): CAD-on- trilayer structure (IPS e.max ZirCAD/IPS e.max Crystall./Connect/IPS e.max CAD); YLD- bilayer structure (IPS e.max ZirCAD/IPS e.max Ceram); LDC- monolithic structure (IPS e.max CAD); and YZW- monolithic structure (Zenostar Zr Translucent). All ceramic specimens were bonded to G10 and subjected to compressive load in 37°C distilled water until the sound of the first crack, monitored acoustically. Failure load (Lf) values were recorded (N) and statistically analyzed using Weibull distribution, Kruskal-Wallis test, and Student-Newman-Keuls test (α=0.05).
  
  
  
  Lfvalues of CAD-on and YZW structures were statistically similar (p=0.917), but higher than YLD and LDC (p<0.01). Weibull modulus (m) values were statistically similar for all experimental groups. Monolithic structures (LDC and YZW) failed from radial cracks. Failures in the CAD-on and YLD groups showed, predominantly, both radial and cone cracks.
  
  
  
  Monolithic zirconia (YZW) and CAD-on structures showed similar failure resistance and reliability, but a different fracture behavior.
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Alessandretti
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
authors.forename: Marcia
authors.initials: M
authors.lastname: Borba
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
authors.forename: Paula
authors.initials: P
authors.lastname: Benetti
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
authors.forename: Pedro Henrique
authors.initials: PH
authors.lastname: Corazza
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil.
authors.forename: Raissa
authors.initials: R
authors.lastname: Ribeiro
authors.affiliation: Postgraduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil. Electronic address: dbona@upf.br.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Della Bona
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D003776:Dental Porcelain; D008422:Materials Testing; D015203:Reproducibility of Results
chemical_list: D003776:Dental Porcelain
keywords: CAD/CAM; Ceramic; Fractography; Multilayer structures; Sound detection