sodium-hypochlorite and 4-toluenesulfinic-acid

To evaluate the effects of different antioxidant treatments on the microtensile bond strength of an adhesive system to sodium hypochlorite (NaOCl)-treated dentin.. Thirty extracted third molars were sectioned 3 mm below the occlusal surface and divided into six groups according to the antioxidant treatment received: control group: distilled water; NaOCl group: 5.25% NaOCl and distilled water; proanthocyanidin (PA) group: 5.25% NaOCl, 5% PA and distilled water; 1-week storage group: 5.25% NaOCl and storage for 1 week in distilled water; Accel group: 5.25% NaOCl, Accel, and distilled water; noni group: 5.25% NaOCl, noni fruit juice, and distilled water. NaOCl, PA, Accel, noni, and distilled water were administered for 30 s, 10 min, 30 s, 10 min, and 30 s, respectively. A self-etching adhesive system (Single Bond Universal Adhesive) was applied to each specimen and a resin composite (Filtek Z550) was built up to a height of 5 mm on the dentin surface. Each specimen was serially sectioned to obtain sticks with a cross-sectional area of 1 mm2, and their microtensile bond strength was determined. Statistical differences between groups were analyzed using one-way ANOVA and Tamhane's T2 test.. Microtensile bond strength in the NaOCl group was significantly lower than in all other groups. However, there were no significant differences in the bond strength between the groups treated with different antioxidants.. NaOCl significantly reduced the microtensile bond strength of the adhesive system. The application of PA, Accel, and noni fruit juice to NaOCl-treated dentin significantly improved the microtensile bond strength.

Topics: Antioxidants; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Fruit and Vegetable Juices; Humans; Materials Testing; Morinda; Proanthocyanidins; Root Canal Irrigants; Sodium Hypochlorite; Stress, Mechanical; Tensile Strength; Time Factors; Toluene; Water

This study aimed to investigate deproteinizing effect of sodium-hypochlorite (NaOCl) and mild acidic hypochlorous-acid (HOCl) pretreatment on smear layer-covered dentine and to evaluate their effects on morphological characteristics of resin-dentine interface with self-etch adhesive.. Human coronal-dentine discs with standardized smear layer were pretreated with 6% NaOCl or 50ppm HOCl for 15s or 30s. Their deproteinizing effects at the treated smear layer-covered dentine surfaces were determined by the measurement of amide:phosphate ratio using ATR-FTIR analysis. In addition, using TEM, micromorphological alterations of hybridized complex and nanoleakage expression were evaluated at the interface of a self-etch adhesive (Clearfil SE Bond) to the pretreated dentine surface with or without subsequent application of a reducing agent (p-Toluenesulfinic acid salt; Accel(®)).. Both pretreatments of NaOCl and HOCl significantly reduced the amide:phosphate ratio as compared with the no-pretreated group (p<0.05), coincident with the elimination of the hybridized smear layer on their bonded interfaces. Nanoleakage within the hybrid layer was found in the no-pretreated and NaOCl-pretreated groups, whereas the subsequent reducing agent application changed the reticular nanoleakage to spotted type. HOCl-pretreated groups showed less nanoleakage expression in a spotted pattern, regardless of reducing agent application.. NaOCl and HOCl solutions could remove the organic component on the smear layer-covered dentine, which could eliminate the hybridized smear layer created by self-etch adhesive, leading to the reduction of nanoleakage expression within hybrid layer.. Smear layer deproteinizing could modify dentine surface, giving an appropriate substrate for bonding to self-etch adhesive system.

Topics: Amides; Collagen; Composite Resins; Dental Bonding; Dental Leakage; Dental Materials; Dentin; Humans; Hypochlorous Acid; Materials Testing; Microscopy, Electron, Transmission; Phosphates; Random Allocation; Reducing Agents; Resin Cements; Root Canal Irrigants; Smear Layer; Sodium Hypochlorite; Spectroscopy, Fourier Transform Infrared; Surface Properties; Time Factors; Toluene

The use of sodium hypochlorite (NaOCl) can decrease the bond strength of 4-META/MMA-TBB resin cement to root dentin. The aim of this in vitro study was to evaluate the effect of sodium toluene sulfinic acid (SA) as a pretreatment to increase bond strength to NaOCl-treated dentin.. The root canal dentin of bovine teeth was treated with 6 methods: group 10-3 (10% citric acid/3% ferric chloride; control); group SA; group NC (sodium hypochlorite/10-3 solution); group NS-10-3 (NaOCl + sulfinic acid + 10-3 solution); group HSA-10-3 (NaOCl +H2O2 +NaOCl + sulfinic acid + 10-3 solution); group HO-10-3 (NaOCl + H2O2 + NaOCl +10-3 solution). The roots were then filled with Super-Bond C&B (SB) or Super-Bond sealer (SBS). Samples were stored in distilled water for 24 h at 37°C and then cross sectioned into five slabs (0.8 mm thick) that were subjected to "trimming" microtensile bond strength testing. All treated dentin surfaces and resin/dentin bond interfaces were analyzed under SEM.. Compared with the control, NaOCl treatment significantly decreased the resin/dentin bond strengths. However, SA treatment following NaOCl irrigation resulted in no significant differences of bond strength values.. Sulfinic acid was effective in restoring 4-META/MMA-TBB resin cement bond strength after NaOCl irrigation.

Topics: Animals; Boron Compounds; Cattle; Dental Bonding; Dental Pulp Cavity; Dental Stress Analysis; Dentin; Dentin Permeability; Dentin-Bonding Agents; Methacrylates; Methylmethacrylates; Microscopy, Electron, Scanning; Resin Cements; Root Canal Irrigants; Sodium Hypochlorite; Tensile Strength; Toluene