The present study examined a technique for reducing dentin permeability through the application of a calcium phosphate (CaP)-based desensitiser with a laser-assisted process and evaluated adhesive-dentin bond strength. Methods: Thirty dentin discs were divided into two groups according to whether the selected desensitiser (TeethMate; Kuraray Noritake) was used prior to dentin bonding. Each group was subdivided into three subgroups (n = 5): A- Adhesive (Single Bond Universal, 3M ESPE), AL- Adhesive + Laser (Nd:YAG 60 mJ) and LAL- Laser + Adhesive + Laser. Dentin permeability values (%) were recorded before and after desensitiser application. Resin composites were placed over the bonded specimens; the latter were aged prior to microtensile bond strength evaluation. Gelatinolytic activity within the hybrid layers was examined with in-situ zymography using confocal laser scanning microscopy. Data were analysed with ANOVA and Tukey test (α = 0.05). Significant differences in dentin permeability were identified for all groups (p = 0.00). Both laser treatment (p = 0.182) and desensitiser application (p = 0.687) did not significantly improve dentin bond strength. Ultrastructure of the resin-dentin interface identified presence of calcium phosphate within dentinal tubules. Laser treatment did not affect hybrid layer ultrastructure. Both treatment modalities (intratubular CaP occlusion and laser) had no influence on gelatinolytic activity within hybrid layers. Although intratubular CaP occlusion and laser treatment were effective in reducing dentin permeability, they did not affect bond strength, interfacial ultrastructure and gelatinolytic activity within hybrid layers. Treatment of etched dentin with Nd:YAG Laser at 60 mJ does not adversely affect collagen ultrastructure and gelatinolytic activity within the hybrid layer. The application of a calcium phosphate-based desensitiser to etch dentin does not affect dentin bond strength.

This study aimed to evaluate Nd:YAG laser, calcium phosphate, and adhesive system effect as different pretreatments in different protocols on dentin permeability (DP) and bond strength (BS). Fifty human dentin discs were used (4 mm in diameter and 1,5 mm in height). Specimens were divided into five groups (n = 10): (A): adhesive system (control); (AL): adhesive system + Nd:YAG laser; (LAL): Nd:YAG laser + adhesive system + Nd:YAG laser; (PAL): calcium phosphate-based dentin desensitizer TeethMate + adhesive system + Nd:YAG laser; and group (PLAL): Nd:YAG laser + calcium phosphate-based dentin desensitizer + adhesive system + Nd:YAG laser. All materials were used according to the manufacturers’ instructions. The specimens were submitted to artificial aging (5,000 thermal cycles and 12 × 10⁴ mechanical cycles) then a bond test was performed. DP was measured using the split chamber model. Data were submitted to one-way analysis of variance (ANOVA), paired t-test, RM ANOVA, and Tukey test ( ). All treatments were effective in DP reduction. For BS, the groups PAL and PLAL had improved BS with a statistically significant difference of the control group (A). Nd:Yag laser irradiation and calcium phosphate-based desensitizing agents significantly reduced DP, and the association between them could improve the BS on resin–human dentin interface.

Background/Objectives: Intraoral scanners (IOS) are increasingly integrated into dental curricula, yet evidence on how brief structured training affects novice students remains limited, particularly in resource-constrained settings. This pilot quasi-experimental study evaluated the effect of a structured IOS training program on the self-reported perceptions of undergraduate dental students with no prior IOS experience. Methods: Twenty first- and third-semester students at the School of Dentistry, Universidad de Especialidades Espíritu Santo (Ecuador), completed a 5-item Likert-type questionnaire (1–9 scale) before and after a training program comprising theoretical instruction and typodont-based practical sessions using a TRIOS 3 scanner (3Shape, Copenhagen, Denmark). Paired Student’s t-tests and Wilcoxon signed-rank tests were used to compare pre- and post-training scores, and effect sizes (Cohen’s d) were calculated for each dimension. Results: Significant improvements were observed in all five perception dimensions (all p < 0.001): familiarity (mean difference: +3.45; d = 1.74), comfort (+3.25; d = 1.91), confidence (+3.70; d = 2.06), perceived scan accuracy (+3.30; d = 1.61), and software competence (+3.55; d = 1.59). Conclusions: A brief, structured IOS training program produced large improvements in students’ self-reported perceptions. These findings support the early integration of IOS training into the dental curriculum. Future controlled studies should assess objective performance outcomes and long-term skill retention.