Abstract
The aim of this study was to evaluate the retentive strength of zirconium oxide (yttria-stabilized tetragonal zirconia polycrystals (Y-TZP)) crown-copings treated by combined mechanical and chemical treatments and cemented by four types of self-adhesive resin cements (SARCs) to human prepared teeth, before and after six months of aging in water and thermocycling. A total of 120 molar teeth were mounted, prepared using a standardized protocol and digitally scanned, and Y-TZP copings were produced. Teeth were randomly assigned to four SARC groups. Prior to cementation, the intaglio surfaces of all crowns were sandblasted and then coated with Z-Prime™ Plus (Bisco Dental, Schaumburg, IL, USA). Post cementation, each cement group was subdivided into aged and non-aged groups. After aging, the cemented assemblies were tested for retentive strength using a universal testing machine. Failure analysis was conducted by inspecting all matched debonded surfaces of the teeth and crowns at 3× magnification. Aging treatment did not affect the retentive strength of the Y-TZP crown-copings (p = 0.918). The interaction between cement and aging was statistically significant (p = 0.024). No significant differences in the retentive strengths between the different SARCs were observed pre-aging (p = 0.776), whereas post-aging, Panavia SA (PAN; Kuraray Dental Co Ltd., Osaka, Japan) showed significantly higher strength than RelyX U-200 (RU200; 3M ESPE, Seefeld, Germany). The predominant failure mode was adhesive between the cement and dentin, followed by mixed mode failure.
Highlights
The increased demand for esthetic restorations has led to a tremendous shift toward all-ceramic materials as an alternative to metal-ceramic restorations
Y-TZP crowns can be cemented to human dentin by conventional cements, adhesive resin cements in total-etch (TE) or self-etch (SE) modes and self-adhesive resin cements (SARCs)
Two-way analysis of variance revealed that the aging treatment did not affect the retentive strength of the Y-TZP crown-copings (p = 0.918)
Summary
The increased demand for esthetic restorations has led to a tremendous shift toward all-ceramic materials as an alternative to metal-ceramic restorations. With the development of computer-assisted design/computer-aided manufacturing (CAD/CAM) systems, zirconium oxide (Y-TZP) ceramics have gained popularity due to their superiority to metal-ceramic restorations esthetically, mechanical stability and biocompatibility [1,2]. High flexural strength (900–1200 MPa) and high fracture resistance (more than 2000 N) make zirconium oxide ceramics suitable for fixed partial dentures (FPDs) supported by teeth and implants [3]. The long-term clinical success of Y-TZP FDPs is determined by the mechanical strength of the material and by the cementation process, by the adhesion of the cements to both the tooth structure and the restoration material [4].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
