Statement of problem: The 3D-printed denture base resin needed reinforcement. Purpose: To evaluate the effects of adding nano ZrO2 and nano TiO2 on microbial colonization and patient satisfaction with 3D-printed maxillary complete dentures. Materials and methods: Twenty-four patients who needed complete dentures were randomly distributed into three equal groups. Group I: Patients used maxillary complete dentures 3D printed without the addition of any additives. Group II: Patients used maxillary complete dentures 3D after reinforcement by Nano-ZrO₂ (0.4%) by weight. Group III: Patients used maxillary complete dentures 3D printed after reinforcement by Nano-TiO₂ (0.4%) by weight. For microbial evaluation, a cotton swab was taken from the mucosa of the palate and the intaglio surface of maxillary dentures, and microbial colonization was evaluated by calculating the number of colony-forming units of S. aureus on mannitol salt agar plates and C. albicans on Sabouraud’s dextrose agar plates after 48 h of incubation at insertion, 6 months, 12 months and 18 months. Patient satisfaction was evaluated 15 days after insertion and at 6, 12, and 18 months. The values of microbial colonization and patient satisfaction were analyzed via repeated-measures ANOVA followed by Tukey’s multiple comparison test. Results: No significant differences in microbial colonization were detected among the three groups concerning Staphylococcus aureus in the palatal mucosa. There was a significant difference between Group I, the lowest antimicrobial group, and the other groups, while between Groups II and III, there was no significant difference in the number of S. aureus on the fitting surface of the denture. There were significant differences between Group II, the highest antifungal group, and the other groups at 12 and 18 months concerning Candida albicans in the palate and in the dentures. There was a significant difference in patient satisfaction between Group I, the lowest, and the other groups, whereas there was no significant difference between Groups II and III. Conclusion: Compared with the other groups, the nano-ZrO₂ group presented greater antimicrobial effects until 18 months, whereas the nano-TiO2 group presented antibacterial effects until 18 months and antifungal effects until 6 months. The addition of nano-ZrO₂ and nano-TiO₂ to 3D-printed denture base resin improved the aesthetic, speech, masticatory efficiency, hygiene, and comfort of patients. Trial registration: The trial was registered in the Clinical Trials Registry under the number NCT06921577 on 10/04/2025 (retrospective registration).

Bular flat ridge. Materials and Methods: This study was carried out on 21 completely edentulous patients with mandibular flat ridge. They were divided randomly into three equal groups; group I: patients used denture adhesive paste, group II: patients used denture adhesive powder, and group III: patients used denture adhesive cushion. For each patient, a cotton swab was taken from the buccal shelf area, and microbial colonization was evaluated by calculating colony forming unit on blood agar after 48 h of incubation. The retention of the denture was measured using a digital force gage in newton before using denture adhesive and at 1, 3, and 6 months after using it. Patient satisfaction was evaluated at 1, 3, and 6 months after using denture adhesives. The values of microbial colonization, retention, and patient satisfaction were analyzed using analysis of variance and paired Student’s t-test followed by Tukey’s test. Results: No significant difference was found between the three groups in microbial colonization. The retention of mandibular denture was increased in the three groups with no significance difference between them. There was also no significant difference between the three groups with regard to patient satisfaction. Cushion form denture adhesive gave long time of retention, followed by paste form and then powder form denture adhesive. Conclusion: The number of microorganisms was not increased or decreased by using denture adhesives. Retention of mandibular denture was increased by using denture adhesive, whether paste or powder or cushion, with no significant difference between them....