Innovative Dentin Remineralization and Tubule Occlusion Using Titanium Dioxide–Doped Phosphate Glass and Diode Laser: An In Vitro Study

Titanium dioxide-doped phosphate glass (TDPG) is silica-free with enhanced chemical stability and ion release properties that could help in dentin remineralization. There is no evidence, however, regarding whether diode laser irradiation can enhance the clinical performance of TDPG paste in this regard. This article aims to evaluate the in vitro effectiveness of the combined use of TDPG paste and diode laser in occluding dentinal tubules, promoting dentin remineralization, and resisting acid challenge in comparison to a commercially available fluoride-containing NuPro prophy paste.This article aims to evaluate the in vitro effectiveness of the combined use of TDPG paste and diode laser in occluding dentinal tubules, promoting dentin remineralization, and resisting acid challenge in comparison to a commercially available fluoride-containing NuPro prophy paste.Seventy mid-coronal dentin discs were prepared from extracted human premolar and molar teeth and randomly distributed into seven groups (<i>n</i> = 10): sound dentin (control), etched dentin (negative control), etched dentin + diode laser, TDPG, TDPG + diode laser, NuPro, and NuPro + diode laser. Treatments were applied accordingly, followed by a 6% citric acid challenge to assess acid resistance. Scanning electron microscopy (SEM) and Raman spectroscopy (RS) were used to evaluate dentinal tubule occlusion and quantify mineral content [phosphate (960 cm^-1) and carbonate (1,070 cm^-1)] before and after the acid challenge, respectively.SEM analysis showed incomplete tubules' occlusion with TDPG and a more uniform surface coverage with NuPro. Laser irradiation improved surface sealing for both materials. After the acidic challenge, NuPro + laser demonstrated better surface integrity, while TDPG + laser showed moderate resistance. RS revealed a significant reduction in the intensity of the phosphate peak after acid exposure in the NuPro groups, particularly with laser (45.8 and 48.9%, respectively), despite the initial high intensity in comparison to a reduction of 1.8% in the TDPG + laser group. TDPG-treated groups demonstrated increased phosphate and carbonate intensities post-acid challenge. Carbonate intensity followed similar trends, confirming greater acid resistance of TDPG formulations compared with NuPro.TDPG paste demonstrated a more chemically stable remineralization process, while NuPro prophy paste achieved better surface integrity after acidic challenge when used with a diode laser, but laser-induced damage in the form of microcracks was evident. The use of diode lasers may enhance the interaction and penetration of desensitizing agents, although compatibility with material composition must be improved for long-term performance.For immediate symptomatic relief of dentin hypersensitivity, a dual strategy using NuPro + laser is indicated. However, to achieve a sustained mineral reinforcement, the combined use of TDPG-based therapies with laser is recommended.