Effect of Diode Laser and Warm Air Drying on the Shear Bond Strength of Lithium Di-silicate to Dentin. An In-vitro Study

Objective: This study aimed to assess the effect of diode laser irradiation (980 nm) and warm air drying (50°C) on shear bond strength between Lithium di-silicate and human dentin using both Etch & Rinse (ER) adhesive, Adper Single Bond 2 and Self-etch (SE) adhesive, Single Bond Universal before adhesive polymerization. Materials and methods: One hundred and eight sound lower molars were sectioned perpendicular to the long axis to obtain flat dentinal surfaces. Specimens were divided into 2 equal groups (n=54): Group 1 (ER) and Group 2 (SE) according to bonding approach. Each group was subdivided according to dentin moisture elimination technique into 3 equal subgroups (n=18): Control (Co), Diode laser irradiation (L) and Warm air drying (W). All specimens were adhesively cemented to IPS e.max® CAD discs using RelyX™ Ultimate Clicker™ (3M ESPE) resin cement. Half of the samples were then subjected to pre-loading in a thermodynamic manner (C=9). Afterwards, all samples were tested for shear bond strength using computer-controlled material testing machine. Results: Data analysis was performed using three-way (ANOVA) (p< 0.05) followed by pair-wise Tukey’s post-hoc tests. Three-way ANOVA showed significant difference between moisture elimination techniques in both groups, except ERNC. Also, for both groups, subgroup (W) had the highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup. Conclusion: Warm air drying for both bonding approaches increased shear bond strength of IPS e.max to human dentin and can be introduced to enhance bonding to dentin.