EVALUATION OF BOND STRENGTH BETWEEN DIFFERENT SYSTEMS FOR ADHESIVE CEMENTATION TO FELDSPATHIC PORCELAIN AND ZIRCONIUM OXIDE

Introduction: New systems for adhesive cementation have been increasingly developed and used in daily clinical practice for the cementation of ceramic prostheses. Differences in the chemical composition of various system components can influence the bond strength between the resin cement and the ceramic. Objective: This study aims to evaluate the bond strength between two ceramic systems—feldspathic porcelain and yttria-stabilized zirconium oxide—and three different systems for adhesive cementation: Rely X ARC, Multilink System, and Rely X UCem. Methodology: Thirty discs of Noritake feldspathic porcelain and thirty discs of zirconium oxide ceramic were fabricated, each measuring 7.5 mm in diameter by 3.0 mm in thickness, according to the manufacturers’ instructions. The discs were polished on a mechanical polisher with water sandpaper ranging from 320 to 1500 grit and embedded in ½ inch PVC tubes with self-curing acrylic resin. The feldspathic porcelain discs were conditioned with 10% hydrofluoric acid for 120 seconds, and the zirconium oxide discs were sandblasted with 40 psi alumina for 10 seconds at 10 mm. All discs were then washed and placed in an ultrasonic bath with distilled water for 10 minutes. The cementation systems were applied according to the manufacturers’ instructions (n=10) on an adhesion area of 5.0 mm in diameter, delimited by a tripartite metal matrix. The samples underwent 1,000 thermal cycles ranging from 5°C to 55°C. Shear bond strength tests were performed on an EMIC DL2000 testing machine with a 20 kN load cell and a speed of 0.5 mm/min. The mean values of the groups were as follows (in MPa): Feldspathic with Rely X ARC (G1) 6.21; Feldspathic with Multilink (G2) 8.98; Feldspathic with Rely X UCem (G3) 8.15; Zirconium Oxide with Rely X ARC (G4) 0.53; Zirconium Oxide with Multilink (G5) 9.25; Zirconium Oxide with Rely X UCem (G6) 4.37. Data were subjected to one-way ANOVA and Tukey tests. Results: There was no significant difference among the feldspathic porcelain groups. For zirconium oxide, Multilink showed higher bond strength values. Conclusion: The bond strength between the cements and feldspathic porcelain exceeded the intrinsic strength of this material, and Multilink showed the highest bond strength values regardless of the ceramic material.