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Objective: To evaluate the effect of enamel conditioning methods, that is, total-etch and rinse (TER), Er,- Cr:YSGG (ECYL), and photodynamic therapy (PDT) on the shear bond strength (SBS) of orthodontic metallic brackets bonded using Zirconium oxide experimental adhesive (ZOEA). Methods: Sixty human incisor buccal surfaces were cleaned and allocated into three groups based on the method of enamel surface treatment, that is, TER using 37% phosphoric acid gel, methylene blue photosensitizer activated by PDT and ECYL (n = 20 each). Each group was further divided into two subgroups (n = 10) based on the type of adhesive, that is, ZOEA and experimental adhesive (EA). Metallic brackets were seated using composite resin. Samples were placed in a universal testing machine for SBS and failure mode using the ARI index. One-way analysis of variance and post hoc Tukey were used for multiple comparisons. ARI was presented in percentages in different investigated groups. Results: TER+ZOEA (17.16 - 0.41 MPa) displayed the highest bond integrity. However, group PDT+EA (11.34 - 0.25 MPa) demonstrated the lowest bond scores. The intergroup comparison revealed that the TER system displayed significantly higher SBS values than the PDT and ECYL groups (p < 0.05). The intragroup comparison revealed that enamel conditioned with TER and brackets bonded with ZOEA and EA displayed comparable bond integrity (p > 0.05). Conclusions: Enamel conditioned with TER bonded to a metallic bracket displayed better bond strength than PDT and ECYL. Zirconium oxide nanoparticles incorporated in adhesive have proved to be promising in improving the bond integrity of adhesive. [ABSTRACT FROM AUTHOR]

Objective: To assess the efficiency of photodynamic therapy (PDT) adjunct to full mouth scaling (FMS) in improving periodontal, microbiological, and proinflammatory cytokines levels in patients undergoing fixed orthodontics treatment (FOT). Materials and methods: The study recruited 60 teenage patients who were undergoing FOT. All the patients were arbitrarily divided into two groups: Group 1, FMS +PDT and Group 2, FMS alone. Plaque scores (PS), bleeding on probing (BOP), and probing depth (PD) were assessed. Levels of biomarkers interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-a) using enzyme-linked immunosorbent assay were evaluated. Samples were collected from gingival plaque for estimation of Prevotella intermedia and Porphyromonas gingivalis load. All measurements were completed at three intervals baseline, 4th week, and 8th week. Post Hoc corrections and intergroup comparisons were examined using Student’s t-test and Bonferroni correction. To find differences between repeated follow-ups, analysis of variance (ANOVA) multiple rank tests were used. Results: At baseline, all the gingival parameters displayed comparable outcomes between patients of Group 1 and Group 2 ( p > 0.05). However, at 4 and 8 weeks of follow-up, PS and BOP among tested groups exhibited significantly lower values than baseline ( p < 0.001). At 8 weeks, there was a significant difference in PS between the two groups tested. Moreover, at 4 and 8 weeks, BOP revealed a significant difference between the groups. PD remains comparable with baseline at follow-up visits ( p > 0.05). A significant decrease in IL-6 and TNF-a levels was observed in both investigated groups at 4 and 8 weeks of baseline. Moreover, it was identified that P. intermedia and P. gingivalis were reduced significantly at 4 weeks. Moreover, a significant difference existed between both Group 1 and Group 2 at 4 and 8 weeks of recall visit ( p < 0.05). Conclusions: The use of photodynamic treatment adjuvant to FMS aids in improving periodontal parameters and cytokines levels. [ABSTRACT FROM AUTHOR]