Effect of dentin desensitizers and Nd:YAG laser pre-treatment on microshear bond strength of adhesive resin cement to dentin

Objectives: The aim of this study was to evaluate how microshear bond strength of different adhesive resin cements are affected by dentin desensitizers application and preparation depth. Materials and Methods: One hundred and forty-four maxillary incisors were randomly divided into two groups according to dentin preparation depth (0.8 and 1 mm) and each group subdivided into four dentin desensitizers, Nd:YAG (Neodymium-doped Yttrium aluminum Garnet) laser and control groups. The dentin desensitizers used were Gluma [Glutaraldehyde/ Hydroxyethyl methacrylate (HEMA)], BisBlock (Oxalate) Vivasens-Potassium Fluoride (KF) and Admira Protect (Ormocer/HEMA), respectively. Three dual cure resin based luting cement (RelyX ARC; Variolink II and Maxcem Elite) were used to create a 0.7 mm diameter and 1 mm height cylindirical shape buid-up in tygon tubes (n=10). Micro-shear bond strength (µSBS) test was performed at a crosshead of speed of 0.5 mm/min using a Universal testing device. Then tooth surface was investigated by steromicroscope and scanning electron microscopy (SEM). Data were analyzed using Kruskal-Wallis, Mann-Whitney U and Chi-Square (X2) tests. (p = 0.05) Results: There was no statistically difference between the groups at 0.8 mm preparation depth. At 1 mm preparation dept RelyX ARC + Gluma groups' mean bond strength value (23.96 ± 6.66 MPa) was found statistically lower according to the other groups (p < 0.05). RelyX ARC + Laser groups' mean bond strength value (37.33 ± 7.39 MPa) was found statistically higher according to the other groups (p < 0.05). Conclusions: The use of desensitizing agents affected the bond strength of the resin cements to superficial dentin. Gluma desensitizer affected negatively µSBS of RelyX ARC resin cement at 1 mm depth. Application of Nd:YAG laser to superficial dentin showed positive effects to the dentin surface and bond strength. Other desensitizing agents showed no significant effects on the resin bond strength (p > 0.05). © 2019 Cumhuriyet Dental Journal.Firat University Scientific Research Projects Management UnitThis work is based on a thesis submitted to the Cumhuriyet University Institute of Health Sciences, for the PhD Degree. and also supported by Cumhuriyet University Scientific Research Projects Governing Unit [Project Number: DIS.68]