sodium-hypochlorite and 4-methacryloxyethyltrimellitic-acid-anhydride

To visualize the complete protection of restored dentin in the acidic environment by the complete impregnation of resin into demineralized dentin.. Class V cavities prepared in extracted human molars composed of enamel, cementum and dentin surfaces were sealed using either 4-META/MMA-TBB resin with conditioning periods of 10, 30, 60 seconds with 10% citric acid and 3% ferric chloride mixed aqueous solution (10-3) or Single-Bond 2 adhesives prior to restoration with light-cured resin-composite. Specimens were either immersed in artificial saliva or 0.1 mol/L buffered lactic acid solutions at 37°C for 14 days. After immersion in 0.5% basic fuchsin dye for 24 hours, the extent of dye penetration at the margin was measured. SEM micrography was used to investigate the quality of hybridized dentin when immersed in HCl followed by NaOCl solutions.. After lactic acid exposure, dye penetration into the adjacent demineralized cementum/dentin was found to be significantly lower than the leakage distance under 30 and 60 seconds and Single-Bond 2 specimens. Leakage-free margins were found in 10-second conditioning period specimens for both control and after soaking in buffered lactic solution with the stable hybridized dentin after chemical challenge.. A leakage-free interfacial layer, provided by complete hybrid layer formation, can block lactic acid penetration. Using this novel prognosis test for visualization of demineralized dentin, clinical restorations are likely to be more reliably predictable in the prevention of initial wall-lesions, post-operative hypersensitivity and/or pulpal infection.

Topics: Bisphenol A-Glycidyl Methacrylate; Boron Compounds; Composite Resins; Dental Leakage; Dental Restoration, Permanent; Humans; Hydrochloric Acid; In Vitro Techniques; Lactic Acid; Methacrylates; Methylmethacrylates; Microscopy, Electron, Scanning; Molar, Third; Prognosis; Sodium Hypochlorite; Surface Properties; Tooth Demineralization

To evaluate the tensile bond durability and ability of four MMA-based adhesive resins to prevent demineralization along the hybrid layer when exposed to a demineralizing solution.. A PMMA rod was bonded to human dentin using one of four MMA-based adhesive systems: Super-Bond C&B (SB), SBP-40TX (SBP, experimental), M-Bond (MB), and M-Bond II (MB II). Bonded specimens were sectioned into 0.9 mm x 0.9 mm beams and subjected to microtensile bond strength (µTBS) testing after water storage at 37°C for 24 h or 10,000 thermal cycles. Data were analyzed with two-way ANOVA and Bonferroni's t-test. Fracture mode analysis of the bonding interface was performed using a scanning electron microscope (SEM) and statistically analysed using the chi-square test. To disclose the demineralization inhibition potential through formation of an acid-base resistant zone (ABRZ), the bonded interface was exposed to a demineralizing solution (pH 4.5) for 90 min, and then 5% NaOCl for 20 min. After argon-ion etching, the interfacial ultrastructure was observed using an SEM.. µTBS values without thermocycling were not significantly different (p > 0.05) among 4 adhesive resins. After thermocycling, a significant decrease in µTBS was found in MB and MB II (p < 0.001), whereas SB and SBP showed no significant change (p > 0.05). Failure modes were significantly different (p < 0.05). An ABRZ was seen in SBP, MB, and MB II, while this protective zone was absent in SB.. Dentin bonding performance after thermocycling was material dependent in MMA-based adhesive resins. The ABRZ formation was only observed in the self-etching systems.

Topics: Boron Compounds; Dental Bonding; Dental Etching; Dentin; Dentin-Bonding Agents; Humans; Hydrogen-Ion Concentration; Materials Testing; Methacrylates; Methylmethacrylate; Methylmethacrylates; Microscopy, Electron, Scanning; Plasma Gases; Polymethyl Methacrylate; Polyurethanes; Resin Cements; Sodium Hypochlorite; Stress, Mechanical; Surface Properties; Temperature; Tensile Strength; Time Factors; Tooth Demineralization; Water

This study aimed at evaluating the effect of functional monomers in all-in-one adhesive systems on formation of acid-base resistant zone (ABRZ) in enamel and dentin. Experimental adhesive systems containing one of three functional monomers; MDP, 3D-SR and 4-META were applied to enamel or dentin surface and light-cured. A universal resin composite was then placed. The specimens were subjected to a demineralizing solution (pH 4.5) and 5% NaClO for acid-base challenge and then observed by SEM. The ABRZ was clearly observed in both enamel and dentin interfaces. However, enamel ABRZ was thinner than dentin ABRZ in all adhesives. Morphology of the ABRZ was different between enamel and dentin, and also among the adhesives. Funnel-shaped erosion was observed only in the enamel specimen with the 4-META adhesive. The formation of enamel/dentin ABRZ was confirmed in all adhesives, but the morphology was influenced by the functional monomers.

Topics: Acetic Acid; Bisphenol A-Glycidyl Methacrylate; Boron Compounds; Calcium Chloride; Composite Resins; Dental Enamel; Dental Materials; Dentin; Humans; Hydrogen-Ion Concentration; Methacrylates; Methylmethacrylates; Microscopy, Electron, Scanning; Phosphates; Polyethylene Glycols; Polymethacrylic Acids; Resin Cements; Sodium Hypochlorite; Temperature; Time Factors; Tooth Demineralization; Tooth Erosion; Water

To test if the hybrid layer formation by Hybrid Root SEAL (Sun Medical Co.), a 4-META-containing auto-adhesive self-etching root canal sealer, is affected by the sequence of irrigants employed for removing canal wall smear layers during root canal treatment.. Single-rooted teeth were shaped and irrigated with EDTA as initial rinse/NaOCl as active final rinse (Group 1), or NaOCl as initial rinse/EDTA as active final rinse (Group 2). All canals were obturated with Hybrid Root SEAL using a single-cone technique. Root slices derived from the coronal, middle and apical thirds of the roots were processed for transmission electron microscopy after removing the gutta-percha, leaving the sealer intact. Additional filled canals from the two groups were evaluated for fluid leakage.. Hybrid layer was absent in Group 1 and was present only when a collagen matrix was produced by EDTA demineralization (Group 2). Significantly more leakage (4.03 +/- 1.94 microL min(-1) vs. 1.50 +/- 0.42 microL min(-1); P < 0.05) was observed in the absence of dentin hybridization.

Topics: Chelating Agents; Collagen; Dental Leakage; Dental Pulp Cavity; Dentin; Edetic Acid; Gutta-Percha; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Transmission; Resin Cements; Root Canal Filling Materials; Root Canal Irrigants; Root Canal Preparation; Smear Layer; Sodium Hypochlorite; Surface Properties

It has been reported that the tensile bond strength between the 4-META/MMA-TBB resin and dentin pretreated with 10% citric/3% ferric chloride solution decreased after immersion in water for 2 years. The current study investigated the effect of an experimental dentin conditioner on the bonding of 4-META/MMA-TBB resin to dentin after thermocycling. The experimental conditioner was an aqueous solution of 10% ascorbic acid and 5% ferric chloride (Exp). Human teeth were prepared to expose flat dentin surfaces. These were treated sequentially with 40% phosphoric acid, 10% sodium hypochlorite, and the experimental conditioner. A commercially available dentin conditioner, an aqueous solution of 10% citric/3% ferric chloride (10-3) was used for a control group. Stainless steel rods were bonded to the pretreated dentin surfaces with the use of the 4-META/MMA-TBB resin. Tensile bond strengths were determined after 0, 5,000, 10,000, 20,000 themocycles. All data were analyzed by ANOVA, and differences among groups were analyzed by Duncan's new multiple range test (n = 10, p < 0.05). The experimental group showed no significant decrease in bond strength through 20,000 thermocycles, while the control group exhibited significant decrease after 10,000 thermocycles. Mean bond strength of the experimental groups were significantly higher than those of the control group at both 10,000 and 20,000 thermocycles. A hybrid layer could not be identified in SEM micrographs of the experimental groups. 10-3-conditioned specimen SEMs displayed crack formation between the adhesive resin and a hybrid layer. The experimental dentin pretreatment improved the bond strength of a 4-META/MMA-TBB resin to human dentin compared to 10-3 treatment after thermocycling.

Topics: Acid Etching, Dental; Analysis of Variance; Ascorbic Acid; Biocompatible Materials; Chlorides; Dental Bonding; Dentin; Dentin-Bonding Agents; Ferric Compounds; Hot Temperature; Humans; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Phosphoric Acids; Resin Cements; Sodium Hypochlorite; Surface Properties; Tensile Strength; Time Factors; Tooth; Water

By altering either ferric chloride concentration in 10% citric acid (1% ferric chloride = 10-1; 5% ferric chloride = 10-5; 10% ferric chloride = 10-10) or conditioning periods with an aqueous mixture of 1% citric acid and 1% ferric chloride (1-1), the influence of dentin substrate on bond strength and hybridized dentin in wet bonding of 4-META/MMA-TBB resin was examined.. Dentin surfaces of fresh bovine incisors were conditioned either with 10-1, 10-5, or 10-10 mixtures for 10 s (10-1-10s, 10-5-10s, 10-10-10s groups) or with a 1-1 mixture for 5, 10, 30 or 60 s (1-1-5s, 1-1-10s, 1-1-30s, 1-1-60s groups). Rinsed, demineralized dentin samples were kept wet, primed with 5% 4-META in acetone for 60 s, and bonded with 4-META/MMA-TBB resin. Bonded specimens were trimmed to a mini-dumbbell shape for tensile testing. The cross sections of bonded specimens were modified with HCl and NaOCl in order to assess the hybrid layer. The fractured surfaces of specimens and the hybridized dentin were investigated with SEM.. No significant difference (p > 0.01) in tensile strength was identified between 10-1-10s and 10-5-10s groups (30 MPa), 10-10-10s and 1-1-5s groups (15 MPa), and the three groups conditioned by 1-1-10s, -30s and -60s (40 MPa). The thickness of the hybrid layer increased with increasing either ferric chloride or conditioning periods.. The concentration of ferric chloride in 10% citric acid for wet bonding must be less than 5% in order to provide a reliable bond. When applied from 10 to 60 s, the 1-1 conditioner provided hybridized dentin with reliable tensile bond strength. The thickness of the hybrid layer did not influence the tensile bond strength.

Topics: Acetone; Acid Etching, Dental; Acrylic Resins; Analysis of Variance; Animals; Boron Compounds; Cattle; Chelating Agents; Chlorides; Citric Acid; Dental Bonding; Dentin; Ferric Compounds; Hydrochloric Acid; Methacrylates; Methylmethacrylate; Microscopy, Electron, Scanning; Oxidants; Resin Cements; Sodium Hypochlorite; Statistics as Topic; Stress, Mechanical; Surface Properties; Tensile Strength; Time Factors; Water

This study compared the capability of three composite resin cements to sustain a standard endodontic dowel. All of the systems incorporated some form of smear layer removal on the dentin of the endodontic channel. One system that used a methyl ethyl ketone drying agent provided inadequate clinical resistance to dislodgment of 5.4 DaN. A second cementing system that used only smear layer removal resisted loads at 54.7 DaN. The third cementing regimen that included a surface-initiated dentinal adhesive and smear layer removal recorded retention of 77.4 DaN. This study supported the concept that passively cemented dowels with composite resin can be as effective as actively seated dowels.

Topics: Acrylic Resins; Bisphenol A-Glycidyl Methacrylate; Boron Compounds; Butanones; Cementation; Chlorides; Citrates; Citric Acid; Composite Resins; Dental Bonding; Dental Cements; Dental Implantation, Endosseous, Endodontic; Edetic Acid; Ferric Compounds; Humans; Methacrylates; Methylmethacrylates; Polyethylene Glycols; Polymethacrylic Acids; Prosthesis Failure; Root Canal Irrigants; Root Canal Therapy; Smear Layer; Sodium Hypochlorite; Stress, Mechanical