Effect of Restoration-method/Adhesive-resin-cement-system on Bonding of CAD/CAM Ceramic Restorations

Objectives: The effect of differences in the restoration method and adhesive-resin-cement-system on the bonding of CAD/CAM ceramic restorations after cyclic-loading was examined quantitatively and qualitatively.
Methods: The 72 human maxillary first molars were divided into three restoration groups: MOD-inlay(Inlay), MODP-onlay(Onlay), and crown(Crown). The exposed dentin surfaces of all prepared specimens were treated with an all-in-one adhesive system and a flowable resin composite(Clearfil Universal Bond Quick and Clearfil Majesty ES Flow, Kuraray Noritake Dental). The 24 specimens of each restoration group were further divided into another three groups; a non-filler-containing 4-META/MMA-TBB cement-system(SB:Super-Bond, Sun Medical) and two filler-containing adhesive-resin-cement-system(PV:PANAVIA V5, Kuraray Noritake Dental and CC:Calibra Ceram, Dentsply Sirona). All restoratives were fabricated from VITABLOCS Mark II(VITA) by CEREC system(SW 4.5, Dentsply Sirona) and cemented with each adhesive-resin-cement-system. All restored specimens stored in 37°C water for 1h. and were subjected to cyclic-loading at 157N for 90cycles/min. Two slabs of 1.0mm-thick were obtained from each specimen, and were trimmed into a standardized-dumbbell-shaped-specimen. The micro-tensile-bond-strength(µ-TBS) of each specimen(n=16) was measured. The data were analyzed using two-way ANOVA and Weibull-analysis.
Results: The mean µ-TBS in MPa(Weibull modulus)[PF10/PF90] to Inlay/Onlay/Crown were SB;5.4(1.6) [1.5/10.5]/5.8(2.3) [2.6/9.5]/6.1(1.6) [1.8/11.6], CC;4.9(1.6) [1.3/9.6]/5.1(1.5) [1.2/10.1]/6.4(1.5) [1.3/12.7], PV;5.2(1.9) [1.8/9.3]/5.9(2.2) [2.5/9.9]/7.3(3.0) [3.9/10.9]. The differences for the restoration method and adhesive-resin-cement-system did not significantly influence the µ-TBS. However, there were significant differences in the values of Weibull modulus as a bonding reliability indicator among three types of restoration and three recent typical adhesive resin-cement-systems.
Conclusions: The µ-TBS was not significantly affected by differences in the restoration method or adhesive-resin-cement-system. However, the methods and cement-systems did show significant differences in terms of the bonding reliability and durability.