An assessment of microstructure, dentinal tubule occlusion and X-ray attenuation properties of Nd:YAG laser-enhanced titanium-doped phosphate glass and nano-hydroxyapatite pastes

This research evaluated the dentinal tubule occlusion capabilities of titanium dioxide-doped phosphate glass (TDPG) paste, with and without adjunctive Nd:YAG laser treatment in comparison to nanohydroxyapatite (n-HA) that also contains calcium phosphate. In total, forty etched dentin (ED) discs were allocated into eight groups: untreated ED (G1), laser-treated ED (G2), TDPG paste-applied ED (G3), TDPG paste followed by laser (G4), TDPG microspheres paste-applied ED (G5), microspheres paste followed by laser (G6), n-HA paste-applied ED (G7), and n-HA paste followed by laser (G8). The interventions were assessed using scanning electron microscopy (SEM) for morphological changes, counting opened dentinal tubules and elemental analysis. Additionally, the study incorporated an evaluation of radiological properties, specifically the materials' mass attenuation coefficients, effective atomic numbers, and exposure buildup factors, to ascertain their compatibility with X-ray imaging modalities. Findings indicated that paste application alone created a layer of precipitated crystals, effectively occluding dentinal tubules. Subsequent laser treatment enhanced occlusion by reducing opened dentinal tubules by approximately 50%, created a dense layer of altered TDPG or n-HA crystals with modified phosphorus and calcium composition. The inclusion of radiological assessment suggested that these materials, particularly when combined with laser, have potential not only for treating dentin hypersensitivity but also compatible with radiographic diagnostic processes.