Bond durability of different resin cements to nanohybrid CAD/CAM ceramic material

Document Type : Original Article

Authors

1 Associate Professor, Conservative Dentistry Department, Faculty of Oral and Dental Medicine, Future University، Egypt

2 Associate professorFixed Prosthodontics Faculty of Oral and Dental Medicine Future University in Egypt, Cairo, Egypt

Abstract

Aim: This study was conducted to evaluate the effect of self etch adhesive based resin cement and self adhesive resin cements on the shear bond strength SBS of CAD/CAM nanohybrid ceramics bonded to dentin with and without thermocycling. Materials& methods: Forty molar teeth were selected. The buccal enamel was removed to expose dentin. The crowns were embedded in autopolymerizing acrylic resin. Forty circular specimens of 2.5 mm thickness and 2.5 mm diameter were obtained from CAD/CAM nanohybrid ceramic (Shofu Disc HC) using a low-speed diamond saw with coolant. Ceramics samples were divided into two groups of 20 discs each according to the cement applied either self-etch or self-adhering resin cements. Half of the samples in each group (10 samples) were subjected to thermocycling. Each specimen was thermally aged in a 5 ̊C to 55 ̊C water bath for 5000 cycles. The shear bond strength tests SBS were carried out using a universal testing machine. Failure modes were observed under stereomicroscope. Results: Self-etch resin cement showed higher statistically significant SBS values than self adhesive cements. Thermocycling showed a statistically significant lower SBS values in all the groups. Conclusion: Within the limitations of this study, it could be concluded that, Self- etch adhesive based resin cement is preferred over self-adhering resin cement in bonding of Shofu Disk HC nanohybrid CAD/CAM ceramic to dentin. Thermocycling showed detrimental effect on SBS of Shofu Disk HC nanohybrid CAD/CAM ceramic to dentin regardless the cement type.

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