Dentinal Tubule Occluding Efficacy Of Er: YAG Laser And Universal Adhesive Loaded With Nano-Carbonated Apatite.

ER:YAG laser and experimental resin-based dental adhesive loaded with functionalized carbonated apatite filler were used in this study to evaluate the dentin interaction in terms of penetration and occlusion of the dentinal tubules aiding in the control of dentin hypersensitivity (DH). Spheroidal Carbonated apatite nanoparticles (N-CAP), with an average size of 20±5 nm diameter, were synthesized, characterized, and incorporated in a universal adhesive "All Bond Universal, Bisco, USA", in (2% weight) concentration. Er:YAG laser "Lightwalker, FOTONA, EU" was adjusted to an energy output of 40mJ/ pulse and pulse repetition of 10 Hz for 10 seconds. Dentin specimens were prepared from the buccal surface of 75 extracted sound human molars. The specimens were randomly divided into five groups (n=15) according to the surface treatment: Group (L): Laser only; Group (LB): Laser in combination with adhesive; Group (LBN): Laser in combination with adhesive loaded with N-CAP; Group (B): adhesive only; and Group (BN): adhesive loaded with N-CAP. Depth of penetration and occlusion of the dentinal tubules were assessed using Environmental Scanning Electron Microscope Examination (ESEM). One-way ANOVA was used to compare groups, followed by a pairwise test for multiple comparisons (α=0.05). Groups (LB), and (LBN) showed the highest mean of dentinal tubules' penetration, with a non-significant difference between them. In contrast, the specimens treated with laser only (L) showed the most minor penetration. The employment of ER-YAG laser irradiation with the adhesive loaded with N-CAP was evaluated to be effective in penetrating and occluding the opened dentinal tubules.