Influence of chlorhexidine 2% and sodium hypochlorite 5. 25% on micro-tensile bond strength of Universal adhesive system (G-Premio Bond)

Aim One of the reasons for the failure of adhesion in composite restorations and secondary caries may be the chemical irrigants used during the endodontic treatment. NaOCl is widely used for the biomechanical preparation of root canals due to its antimicrobial properties and capacity to dissolve organic material. In addition, another very effective decontamination solution is chlorhexidine 2%. There are few studies about the effect of root canal irrigation solutions on bond strength of universal adhesives therefore, in this study we have investigated the influence of CHX 2% and NaOCl 5.25% on micro-tensile bond strength of G-Premio Bond. Methods Twenty-four human teeth were randomly allocated to the following groups: G1, immersion in saline solution 0.9% for 30 minutes (control); G2, immersion in CHX 2% for 30 minutes; G3, immersion in NaOCl 5.25% for 30 minutes. After restoration, the dentin/resin interface was tested by micro-tensile bond strength. The surfaces morphology was analyzed by Scanning Electron Microscopy. Data were analyzed by ANOVA followed by Tukey test in SPSS software Version 24. Results There was a statistically significant difference between G3 and G1 (P < 0.05). There were no statistically significant differences among G1 and G2, G2 and G3. Conclusion Root canal irrigation with NaOCl 5.25% significantly reduced the micro-tensile bond strength in the G-Premio Bond at self-etch mode, but the use of CHX did not make a significant difference.

Effects of C-Factor on Bond Strength of Universal Adhesives to Floor and Wall Dentin in Class-I Composite Restorations.

PURPOSE: To evaluate the effects of C-factor on the bond strength of universal adhesives to floor and wall dentin in class-I composite restorations using a bulk-fill composite. MATERIALS AND METHODS: 108 non-carious humans third molars were randomly divided into four groups as follows: flat wall, flat floor, cavity wall, and cavity floor (n = 36). Then, each group was subdivided into three subgroups according to the type of adhesive used: Single Bond Universal, G-premio Bond (both universal adhesives), or Adper Single Bond 2 (an etch-and-rinse adhesive). After the bonding procedure, X-tra fill resin composite was applied in bulk to build up the flat surfaces or fill the cavities.Then the teeth were sectioned into 1-mm2 sticks and microtensile bond strength (µTBS) was measured using a universal testing machine. µTBS (MPa) was analyzed by one-way, two-way, and three-way ANOVA using SPSS Version 23 (a = 0.05). RESULTS: Interactions between adhesives and bonding surfaces, as well as C-factor and bonding surfaces showed statistically significant differences, but the interaction between the C-factor and type of adhesive was not statistically significant. The comparison of bonded surfaces including the flat wall and the flat floor in Adper Single Bond 2 was statistically significant (p < 0.05), except for the cavity wall and cavity floor. CONCLUSION: Regardless of the type of adhesives, the C-factor reduced the µTBS of the composite resin to dentin. Adper Single Bond 2 mediated higher µTBS than did the universal adhesives G-premio Bond and Single Bond Universal.

Comparison of the Efficacy of Dexamethasone and Methylprednisolone in Infiltration Injection for Postendodontic Pain in Patients with Necrotic Pulp: A Randomized Controlled Clinical Trial.

PURPOSE: Postendodontic pain is one of the problems of root canal therapy. This clinical study aimed to evaluate the effect of infiltration injection of dexamethasone and methylprednisolone on postendodontic pain in patients with necrotic pulp. METHODS: A total of 80 volunteers with necrotic pulp teeth were included and assigned to two groups (n = 40). After the administration of local anesthesia and before root canal therapy, in group 1, an infiltration injection of 1 ml of dexamethasone was done and in group 2, an infiltration injection of 1 ml of methylprednisolone was done in the buccal vestibule of each tooth. Patients' pain was reported using a visual analogue scale at pretreatment and 6, 12, 24, and 48 hours after treatment. RESULTS: There was no significant difference between the two groups receiving dexamethasone and methylprednisolone at pretreatment and 6, 12, 24, and 48 hours after endodontic treatment. CONCLUSIONS: Infiltration injection of dexamethasone and methylprednisolone had a significant effect in reducing pain after the endodontic treatment in necrotic pulp teeth, but between 6 and 12 hours, methylprednisolone had significantly more effect on pain relief than dexamethasone. Overall, the use of any of these drugs to reduce postendodontic pain is recommended.

Preparation, and structural of new NiS-SiO2 and Cr2S3-TiO2 nano-catalyst: Photocatalytic and antimicrobial studies.

NiS-SiO2 and Cr2S3-TiO2 synthesized by Ultrasound-Microwave method was tested for the photo-degradation of methyl red as azo dye under ultraviolet (UV) light. The structure and morphology of the synthesized materials were examined through scanning electron microscopy, X-ray diffraction and photoelectron spectroscopy, energy-dispersive spectroscopy, dynamic light scattering and the band gap energy differences were determined through diffuse reflectance spectroscopy (DRS). The crystallite size and band gap values of SiO2, TiO2, NiS-SiO2 and Cr2S3-TiO2-1 were obtained from XRD and UV-vis DRS analysis and found insignificant 44.22, 54.11, and 57.11 nm, and 8.9, 3.2, 3.0, 2.7 eV, respectively. The NiS-SiO2 and Cr2S3-TiO2 nanocomposites exhibited good stability and catalytic performance in the azo dye degradation; the composite provides a complete degradation after 50 min under UV irradiation. The effects of different quencher compounds on the Methyl red dye degradation were also investigated. The result for this experiment shows the system without the quencher was highly degradation of Methyl red. The antibacterial influence of the SiO2, TiO2, NiS-SiO2 and Cr2S3-TiO2-1 were studied versus two species bacteria. The antifungal performance of this nanoparticle was analyzed versus two species fungi as the C. albicans and P. funiculosum. Biological data demonstrated that the prepared catalyst has great bactericidal and fungicidal properties.