J Oral Laser Applications 10 (2010), No. 2-3 (20.12.2010)
Comparison of Tensile Bond Strength of Composite to Dentin in Conventional or Laser-prepared Cavities (Er;Cr:YSGG)
Shahabi, Sima / Chiniforoush, Nasim / Fekrazad, Reza / Fatemi, Saed Mostafa
Purpose: The purpose of this study was to evaluate the effect of Er;Cr:YSGG laser on the tensile strength of composite resin to dentin in comparison with bur-cut cavities.
Materials and Methods: Twelve extracted caries-free human third molars were selected to prepare 24 samples (n = 24). The teeth were cut under the occlusal pit and fissure level and randomly divided into 2 groups. Six cavities were prepared with a diamond fissure bur No.1 and the other group with Er;Cr:YSGG laser with the pre-settings recommended by the manufacturer (power: 3.5 W, 65% water, 55% air). Then, all the cavities were restored using composite resin. The teeth were sectioned longitudally with an Isomet saw and the dumbbellshaped specimens were prepared. The samples were attached to special jigs, and the tensile bond strength of the two groups was measured in a universal testing machine at a crosshead speed of 0.5 mm/min. The results were analyzed with the Kolmogorov-Smirnov test.
Results: The means and standard deviations of tensile bond strength of bur-cut and laser-ablated dentin were 5.04 ± 0.93 and 4.85 ± 0.93 MPa, resp. There was no significant difference between the tensile bond strength in lased and bur-cut cavities (p = 0.5).
Conclusion: There is little difference in the tensile bond strength of composite resin in laser-prepared vs burprepared cavities. According to the results, the Er;Cr:YSGG laser technique can be an alternative to the conventional methods for preparing cavities.
Keywords: Er;Cr:YSGG laser, resin composite, tensile strength