Effect of Dentin Desensitizers and Nd:YAG Laser Pre-Treatment on Microshear Bond Strength of Adhesive Resin Cement to Dentin

Abstract

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 (X 2) 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).

Assessment the Impact of Moringa Oleifera Extracts and Ascorbic Acid Solution as Antioxidants on Microshear Bond Strength of Resin Composite to Bleached Bovine Enamel (In Vitro Study)

“…Bonded specimens were stored in deionized water for 24 h at 37°C before shear bond strength testing to artificially age the composite resins. (6,18) Artificial aging simulates the chemical and physical oral environments, producing in a relatively short period, degradation similar to that which a composite resin would undergo in its clinical life. (38,39) The positive and negative control groups used in this study clearly defined the difference in bond strength between unbleached and bleached enamel immediately restored with resin composite.…”

“…The segments were used as matrices to build up cylindrical resin composite units. (18) Twenty-five polyethylene segments were used to aid in resin composite packing on the labial surface of each tooth. 1 mm of resin composite material (Voco, Amaris.)…”

“…Then, the specimens were stored in distilled water at 37°C for 24 hours. (18) After 24 hours, the specimens were removed from distilled water and jet dried. The polyethylene tygon segments were then cautiously removed using lancet no.11 leaving the resin composite cylinders bonded to enamel surface.…”

“…The polyethylene tygon segments were then cautiously removed using lancet no.11 leaving the resin composite cylinders bonded to enamel surface. (18) All resin composite cylinders were checked using (×6) magnifying glass lens for any defect or air bubble, where if present the specimen was discarded.…”