The 1wt.% ZnOn may preserve the integrity of the hybrid layer and may reduce cytotoxicity and polymerization shrinkage of model dentin adhesive. The addition of Zn-Mt to the adhesive had no beneficial effects.

The aim of this study was to evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (ΔT) and microtensile bond strength (μTBS) to dentin submitted to an adhesive technique using laser irradiation. One hundred sound human molars were randomly divided into two groups (n = 50), according to the presence or absence of SPP (15 cm H2O). Each group was divided into five subgroups (n = 10) according to Nd:YAG laser energy (60, 80, 100, 120, 140 mJ/pulse). The samples were sequentially treated with the following: 37 % phosphoric acid, adhesive (Scotchbond Universal), irradiation with Nd:YAG laser (60 s), and light curing (10 s). ΔT was evaluated during laser irradiation using a type K thermocouple. Next, a composite resin block was build up onto the irradiated area. After 48 h, samples were submitted to microtensile test (10 kgf load cell, 0.5 mm/min). Data were analyzed by two-way ANOVA and Tukey tests (p = 0.05). ANOVA revealed significant differences for ΔT and TBS in the presence of SPP. For ΔT, the highest mean (14.3 ± 3.23 °C)(A) was observed in 140 mJ and without SPP. For μTBS, the highest mean (33.4 ± 4.15 MPa)(A) was observed in 140 mJ and without SPP. SPP significantly reduced both ΔT and μTBS during adhesive procedures, lower laser energy parameters resulted in smaller ΔT, and the laser parameters did not influence the μTBS values.

Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations.ObjectivesThis study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives.Material and MethodsAdhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM).ResultsNo significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups.ConclusionEGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity.

The aim of this study was to evaluate the efficacy of three desensitizing agents to provide relief to dentin hypersensitivity after one session in a four-week follow-up. Forty selected patients participated in a double-blind study following a split-mouth model. One application of the desensitizing agents (A, Admira Protect [Voco]; B, Bifluorid 12 [Voco]; and C, Colgate Pro-Relief in office [Colgate Palmolive]) was performed in three different quadrants for each patient. Each tooth was evaluated by tactile and evaporative stimuli, and the sensitivity response was measured using the Visual Analogue Scale. Evaluations were performed at baseline, immediately after treatment, and after one, two, three, and four weeks. The application of Kruskal-Wallis and Dunn multiple comparisons tests (5%) for both tactile and evaporative stimuli showed that all agents presented a significant desensitizing effect. In groups A and B this relief was maintained for four and three weeks, respectively, as measured by tactile stimulus and for four weeks with evaporative stimulus. The desensitizing effect for group C was maintained for two weeks for both tactile and evaporative stimuli. It is concluded that all desensitizing agents tested were effective in reducing sensitivity compared to baseline values. One application of Admira Protect and Bifluorid 12 presented a longer-lasting desensitizing effect than did Colgate Pro-Relief (applied in the office) on both tactile and evaporative stimuli.

Objective: The aim of this study was to evaluate the bond strength of dentin treated with chlorhexidine, hyaluronic acid, vitamin C and green tea. Material and Methods: The roots of 50 bovine teeth were removed and buccal coronal dentin was exposed. After acid-etching, the specimens were divided into 5 groups (n = 10), according to the dentin treatment strategy: CO - untreated dentin; CHX - treated with 2 wt% chlorhexidine for 30 sec; HA - treated with 1 wt% hyaluronic acid for 30 sec; VC - treated with 10 wt% vitamin C for 30 sec; GT - treated a 1% green tea extract for 30 sec.  Adper Single Bond was then applied to the treated according to the manufacturer's recommendations. The specimens were restored with a 4-mm thick layer of the resin composite, which was polymerized for 40 sec. The specimens were stored in distilled water at 37°C for 24 h and sectioned into 1x1 mm2 sticks containing the adhesive interface. Microtensile bond strength testing was performed with a universal testing machine at a cross-head speed of 1.0 mm/min. Results: The results were analyzed with one-factor ANOVA and Tukey’s multiple comparison tests. GT group presented the highest values bond strength (29.4±3.1)a, but no significant difference compared to the other experimental groups HA(26.7±3.1)ab, CHX(25.4±2.6)ab and VC(22.4±6.0)b. Bond strengths of experimental groups were not significantly different from the CO. Conclusion: Immediate bond strength was preserved after acid-etched dentin was treated.Keywords: Chlorhexidine. Hyaluronic acid. Vitamin C. Green tea. Bond strength.

ObjectiveThe aim of this study was to evaluate the effects of toothbrushing using a fluoride toothpaste and Aloe vera tooth gel on artificial white spot lesions through the Knoop microhardness (KHN) analysis. Methods Sound bovine enamel samples (2 mm/diameter and 2 mm/depth) were prepared and immersed in artificial white spot lesion for 24 h. The preparation of artificial white spot lesions was performed by pH-cycling process. The samples were randomly divided into two groups (n=20), according the dentifrice used: containing fluoride (Colgate Total 12) or Aloe vera (Forever Bright Aloe Vera Toothgel

Scanning electron microscope analysis showed evident areas of micromorphological alterations in lased samples after 12 months of water storage. Nd:YAG laser irradiation of enamel through unpolymerized total-etch adhesive significantly reduced bond strength compared with the control. Bond strength decreased when enamel samples irradiated with Nd:YAG laser through unpolymerized adhesives were stored in water for 12 months.

<p><strong>Objective</strong>: This study evaluated the effect of 0.2% chlorhexidine gluconate solution used as an therapeutic primer on the long-term bond strength of etch-and-rinse adhesive to dentin. <strong>Material</strong> <strong>and</strong> <strong>Methods</strong>: Bovine incisors were worn to expose an area of dentin and were divided into 2 groups: Group C (Control) - acid etching with 37% phosphoric acid + Single Bond; Group CHX (0.2% CHX) - acid etching with 37% phosphoric acid + 0.2% CHX for 30 s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey tests. <strong>Results</strong>: Mean (±SD) values (in MPa) were as follow: Group CHX/24h - 41.8(±2.62)A; Group C/24h - 40.8(±3.35)AB; Group CHX/6 months – 36.4(±3.52)B; Group CHX/6 months - 26.1(±1.54)C. <strong>Conclusion</strong>: CHX improve the imediatte bond strength of resin-dentin and significantly lowered the loss of bond strength after 6 months water storage as seen in the control bonds.</p><p><strong>Keywords</strong></p><p>Tensile bond strength; Dentin; Total-etch adhesives; Chlorhexidine gluconate.</p>