The Influence of Adhesive Systems on Microshear Bond Strength in Bur or Laser-Prepared Enamel

Background: The aim of this study was to assess the microshear bond strength(μSBS) of various adhesive systems on enamel surfaces prepared using either an Er, Cr:YSGG laser or a conventional diamond bur. Methods: Twenty-eight caries-free human molars were longitudinally sectioned, resulting in 56 samples. Buccal or lingual surfaces were embedded in acrylic blocks. Enamel surfaces were prepared using either an Er, Cr: YSGG laser (Biolase Technologies, USA) or a traditional diamond bur (Diatech, Switzerland), referencing the midline of each tooth. Laser treatment was applied to the left side, while the right half underwent bur treatment. The samples were randomly separated into four groups(n=14): [G1] Optibond FL (Kerr, USA), a three-step etch-and-rinse adhesive; [G2] Clearfil SE Bond(Kuraray,Japan), a two-step self-etch adhesive; [G3]Prime&Bond Universal(Dentsply,USA),universal-adhesive/etch-and-rinse-mode; and [G4]Prime&Bond Universal(Dentsply,USA),universal-adhesive/self-etch-mode. Composite cylinders with a diameter of 0.8 mm (Harmonize, Kerr, USA) were affixed to the center of both the laser-prepared and bur-prepared regions of all specimens. The adhesive interface of one randomly chosen representative from each group was analyzed using a Scanning Electron Microscope(SEM). The remaining samples were subjected to μSBS testing. Data were analyzed statistically using Two-Way ANOVA(p0.05). Regardless of the preparation modalities, the adhesive systems did not exhibit any statistically significant differences(p>0.05). Furthermore, the correlation between various adhesive systems and preparation techniques did not result in statistically significant variations in μSBS values(p>0.05). Conclusion: The measured μSBS values of the adhesive systems examined on enamel surfaces prepared using either an Er, Cr:YSGG laser or a diamond bur showed similarity. Keywords: Laser preparation, Microshear bond strength, Scanning electron microscopy, Universal adhesive.