Özet:

Objectives: Lately, computer-aided design (CAD) computer-aided manufacturing (CAM) systems with simplified procedures for indirect restoration have gained rapid improvements and commenced to be used in daily practice of dental clinicians. The aim of this pilot in vitro study was to analyze the bonding efficiency and observation of the failure mode of hybrid ceramic CAD/CAM block materials after termo-cycling, with different immediate dentin sealing (IDS) techniques. Materials and Methods: Eighteen freshly extracted human molars were selected, and mounted with acrylic resin, fixed the root up to 2.0 mm under the cementoenamel junction. Standardized, flat, nonretentive, midcoronal dentin surfaces were prepared. Using the stratified random sampling process, all teeth (N=18) were divided into groups of three by approximately similar sizes; afterwards, these teeth were randomly distributed into the test groups 1, 2 and 3 (n = 6). The specimens from groups 2 and 3 received IDS, whereas delayed dentin sealing was carried out for specimens group 1. For IDS materials, universal adhesive system G-Premio Bond (GC, Tokyo, Japan) and highly filled flowable resin composite G-aenial Universal Flo (GC, Tokyo, Japan) were used. All block material specimens were prepared using the cutting instrument (IsoMet 1000; Buehler, USA) and were fitted with a standardized 3x3-mm3 cubes cutted out of a CAD/CAM block of hybrid ceramic (Cerasmart, GC; Tokyo, Japan). Dual-polymerized resin cement G-CEM Link Force (GC, Tokyo, Japan) was utilized to lute restoration materials for all groups. To test the shear bond strength (SBS) each of the specimens was placed in a jig with 90o to the vertical plane and tested a universal testing machine (Shimadzu AG-IS; Shimadzu Corp). One-way ANOVA was used to analyze the data of the SBS. Results were evaluated statistically significant for p<0.05. Results: No statistically significant difference revealed by the statistical analysis between Group 1,2 and 3 (p=0,372). This means there is no significant difference in the sealing methods (p>0,05). Bond failure rates showed similar results in all groups, where the most frequent failure pattern detected was ‘adhesive type’. Conclusions: Within the limitation of this in vitro pilot study, the following conclusion was drawn: Different IDS procedures tested does not statistically (p<0.05) effect the SBS of hybrid ceramic CAD/CAM material bonded to dentin with G-CEM Link Force.

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