Modulation of implants PEEK to composite resin shear bond strength and surface roughness on pre-treatment with contemporary air abrasion techniques vs photodynamic therapy vs conventional diamond grit bur.

AIM: The chief aim of the study was to determine/equate the surface roughness (SRa) and shear bond strength (BS) of pretreated PEEK discs with contemporary air abrasion techniques, photodynamic (PD) therapy by curcumin photosensitizer (PS) and conventional diamond grit straight fissure bur adhered to the composite resin discs. MATERIAL AND METHOD: Two hundred discs of PEEK were prepared of 6 mm × 2 mm × 10 mm dimension. The discs were randomly divided into five groups (n = 40) for treatment, Group I: treatment with deionized distilled water (control group); Group II: PD therapy using curcumin PS; Group III: discs treated and abraded with air-borne particles (ABP) silica (30 µm particle size) modified alumina (Al); Group IV: ABP of alumina (110 µm particle size); and Group V: The PEEK were finished with 600-µm grit size straight diamond cutting bur installed in high speed hand-piece. The surface profilometer was used to evaluate the values of surface roughness (SRa) of pretreated PEEK discs. The discs were luted and bonded to discs of composite resin. The bonded PEEK samples were placed in Universal testing machine to evaluate shear BS. The type of BS failure for PEEK discs pre-treated with five regimes respectively was evaluated under stereo-microscope. The data was statistically analyzed using one-way ANOVA and the comparisons between mean values of shear BS were evaluated by Tukey's test (ρ≤0.05). RESULTS: The PEEK samples pre-treated with diamond cutting straight fissure burs displayed statistically significant highest value of SRa values (3.258± 0.785 µm). Similarly, the shear BS was observed to be higher for the PEEK discs pre-treated with straight fissure bur (22.37±0.78 MPa). A comparable difference but not statistically significant difference was observed between PEEK discs pre-treated by curcumin PS and ABP-silica modified alumina (ρ ≥ 0.05). CONCLUSION: PEEK discs pre-treated with diamond grit straight fissure bur displayed highest values of SRa and shear BS. It was trailed by ABP-Al pre-treated discs; whereas the SRa and shear BS values for the discs pre-treated with ABP-silica modified Al and curcumin PS did not show competitive difference.

Use of final irrigants MTAD, Salvedora Perscia, Malachite green, and Ti-sapphire laser on push-out bond strength of Zirconia post.

AIM: Evaluation of the push-out bond strength (PBS) of zirconia post-bonded to radicular dentin after using different final irrigants (MTAD, Malachite green (MG), Ti-sapphire laser and Salvadora persica (S.persica). MATERIAL AND METHOD: Forty human permanent single-rooted were decoronated above the cement-enamel junction. An experienced endodontist performed all the root canal instrumentation using ProTaper universal rotary files. Canals were irrigated using 5.25% NaOCl solution followed by EDTA as a final sterilant. Obturation with gutta-percha using AH Plus sealer was performed. Post-space preparation was completed using Gates Glidden and specimens were randomly assigned to four groups based on the final disinfectant received (n=10). Group 1: 5.25% NaOCl + MTAD, group 2: 5.25% NaOCl + MG, group 3: 5.25% NaOCl +Ti-sapphire laser, and group 4: 5.25% NaOCl + S. persica. The chemically polymerized resin was used to lute zirconia posts. PBS and failure mode analysis were performed using a universal testing machine and stereomicroscope at 40X magnification. Data were compared between the two groups with 95% CI using one-way analysis of variance (ANOVA) with the Tukey post hoc test. p=0.05. RESULTS: Group4(5.25% NaOCl+ S.persica) specimens demonstrated the maximum (8.94±0.14 MPa) bond strength. Conversely, the apical third of Group 2 (5.25% NaOCl+ MG) (2.87±0.15 MPa) samples revealed the minimum bond strength scores. Intergroup comparison exposed that Group 1 (1.3% NaOCl+ MTAD), Group 3 (5.25% NaOCl+Ti-sapphire laser), and Group 4 (5.25% NaOCl+ S. persica) at all three-thirds unveiled no significant difference in PBS (p<0.05). CONCLUSION: Ti-sapphire laser and Salvedora Persica possess the potential to be used as a final root canal irrigant to improve the push-out bond strength of zirconia post-to-root dentin.

Therapeutic efficacy of adjunctive photodynamic therapy in the treatment of denture stomatitis.

BACKGROUND: The present report assessed the efficacy of curcumin-mediated photodynamic therapy (CUR-mediated PDT) as an adjunct to antifungal gel treatment by evaluating the salivary interleukin-6 (IL-6) and matrix metalloproteinases-8 (MMP-8) levels together with Candida species counts in denture stomatitis (DS) patients. METHODS: In total, 50 DS subjects were randomly categorized into 2 groups: Group-1: subjects who received the antifungal gel treatment and Group-2: participants who received CUR-mediated PDT. The Sabourad Dextrose Agar and CHROMAgar were utilized for evaluating Candida species counts, while the Enzyme-Linked Immunosorbent Assay was employed to estimate the salivary levels of IL-6 and MMP-8. All clinical evaluations were performed at the baseline, 1 month, and 2 months. RESULTS: In total, group-2 subjects showed a significant decrease in Candida albicans (C. albicans) counts on both follow-ups (i.e., 1-month and 2-month) than group-1 participants. C. krusei count also reduced in group-2 subejcts than group-1 participants at the 2nd follow-up as compared to the baseline, nevertheless, a slight increase in C. krusei count was noticed in group-2 subjects at the 2nd follow-up than the 1st follow-up. The salivary IL-6 and MMP-8 levels in both groups reduced significantly at both follow-ups than the baseline. According to the stepwise logistic regression analysis, no statistically significant correlation was observed between Candida species count and other parameters such as age and gender of the patient, duration of DS, and frequency of treatment(s). CONCLUSION: CUR-mediated PDT is an efficaciousness therapeutic modality for alleviating Candida species counts on the surface of denture and the palatal mucosa, as well as improving the salivary IL-6 and MMP-8 levels in DS patients.