Effects of Surface Hydration State and Application Method on the Bond Strength of Self-etching Adhesives to Cut Enamel

Purpose: To evaluate the effect of surface hydration state and application method on the microtensile bond strength of one-step self-etching adhesives systems to cut enamel.Materials and Methods: One hundred ninety-five bovine teeth were used. The enamel on the buccal side was flattened with 600-grit SiC paper. For the control group, 15 teeth received Adper Single Bond 2, applied according to manufacturer's recommendations. The other specimens were divided into three groups according to the adhesive system used: Futura Bond M (FM; Voco), Clearfil S-3 Bond (CS; Kuraray), and Optibond All in One (OA; Kerr). For each group, two hydration states were tested: D: blown dry with air; W: the excess of water was removed with absorbent paper. Two application methods were tested: P (passive): the adhesive was simply left on the surface; A (active): the adhesive was rubbed with an applicator point. A coat of Grandio composite resin (Voco) was applied on the surface. The teeth were sectioned to obtain enamel-resin sticks (1 x 1 mm), which underwent microtensile bond testing. The data in MPa were submitted to a three-way ANOVA and Tukey's test (alpha = 5%).Results: The ANOVA showed significant differences for application method and the type of adhesive, but not for hydration state. For the application method, the results of Tukey's test were: P: 31.46 (+/-7.09)a; A: 34.04 (+/-7.19)b. For the type of adhesive, the results were: OA: 31.29 (+/-7.05)a; CS: 32.28 (+/-7.14)a; FM: 34.68 (+/-7.17)b; different lower-case letters indicate statistically significant differences.Conclusion: Active application improved the bond strength to cut enamel. The adhesive Futurabond M showed the highest bond strength to cut enamel.

Micro-Shear Bond Strength of Different Adhesives to Human Dental Enamel

The aim of this study was to evaluate the micro-shear bond strength of 5 adhesive systems to enamel, one single-bottle acid-etch adhesive (O), two self-etching primers (P) and two all-in-one self-etching adhesives (S). Method: Sixty premolar enamel surfaces (buccal or lingual) were ground flat with 400- and 600-grit SiC papers and randomly divided into 5 groups (n=12), according to the adhesive system.. SB2 - Single Bond 2 (O); CSE - Clearfil SE Bond (P); ADS - AdheSE (P); PLP - Adper Prompt L-Pop (S); XE3 - Xeno III (S). Tygon tubing (inner diameter of 0.8mm) restricted the bonding area to obtain the resin composite (Z250) cylinders. After storage in distilled water at 37 degrees C for 24h and thermocycling, micro-shear testing was performed (crosshead speed of 0.5mm/min). Data were submitted to one-way ANOVA and Tukey test (a=5%). Samples were also subjected to stereomicroscopic and SEM evaluations after micro-shear testing. Mean bond strength values (MPa +/- SD) and the results of Tukey test were: SB2: 36.36(+/- 3.34)a; ADS: 33.03(+/- 7.83)a; XE3: 32.76(+/- 5.61)a; CSE: 30.61(+/- 6.68)a; PLP: 22.17(+/- 6.05)b. Groups with the same letter were not statistically different. It can be concluded that no significant difference was there between SB2, ADS, XE3 and CSE, in spite of different etching patterns of these adhesives. Only PLP presented statistically lower bond strengths compared with others. J Clin Pediatr Dent 35(3): 301-304, 2011

BOND STRENGTH DURABILITY of SELF-ETCHING ADHESIVES and RESIN CEMENTS TO DENTIN

Objectives: To evaluate the microtensile bond strength (mu TBS) of one-(Xeno III, Dentsply) and two-step (Tyrian-One Step Plus, Bisco) self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond) or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar) within a short (24 h) and long period of evaluation (90 days). Material and Methods: Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n = 10). The restored teeth were stored in distilled water at 37 C for 7 days. The teeth were then cut along two axes (x and y), producing beam-shaped specimens with 0.8 mm(2) cross-sectional area, which were subjected to mu TBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The mu TBS data in MPa were subjected to three-way analysis of variance and Tukey's test (alpha = 0.05). Results: The interaction effect for all three factors was statistically significant (three-way ANOVA, p < 0.001). All eight experimental means (MPa) were compared by the Tukey's test (p < 0.05) and the following results were obtained: Tyrian-One Step Plus /C&B/24 h (22.4 +/- 7.3); Tyrian-One Step Plus /Variolink II/24 h (39.4 +/- 11.6); Xeno III/C&B/24 h (40.3 +/- 12.9); Xeno III/Variolink II/24 h (25.8 +/- 10.5); Tyrian-One Step Plus / C&B/90 d (22.1 +/- 12.8) Tyrian-One Step Plus/VariolinkII/90 d (24.2 +/- 14.2); Xeno III/C&B/90 d (27.0 +/- 13.5); Xeno III/Variolink II/90 d (33.0 +/- 8.9). Conclusions: Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water.

Photoluminescence properties of PZT 52/48 synthesized by microwave hydrothermal method using PVA with template

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biodegradation of blend films PVA/PVC, PVA/PCL in soil and soil with landfill leachate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adhesives with different pHs: Effect on the MTBS of chemically activated and light-activated composites to human dentin

Purpose: To evaluate the bond strength between human dentin and composites, using two light-activated single-bottle total-etch adhesive systems with different pHs combined with chemically activated and light-activated-composites. The tested hypothesis was that the dentin bond strength is not influenced by an adhesive system of low pH, combined with chemically activated or light-activated composites. Material and Method: Flat dentin surfaces of twenty-eight human third molars were allocated in 4 groups (n=7), depending on the adhesive system: (One Step Plus-OS and Prime & Bond NT-PB) and composite (light-activated Filtek Z-100 [Z100] and chemically activated Bisfil 2B [B2B]). Each adhesive system was applied on acid-etched dentin and then one of the composites was added to form a 5 mm-high resin block. The specimens were stored in tap water (37 degrees C/24 h) and sectioned into two axes, x and y. This was done with a diamond disk under coolant irrigation to obtain beams with a cross-section area of approximately 0.8 mm(2). Each specimen was then attached to a custom-made device and submitted to the microtensile test (1 mm.min(-1)). Data were analyzed using two-way ANOVA and Tukey's tests (p<0.05). Results: the anticipated hypothesis was not confirmed (p<0.0001). The bond strengths (MPa) were not statistically different between the two adhesive systems when light-activated composite was used (OS+Z100 = 24.7 +/- 7.1(a); PB+Z100 = 23.8 +/- 5.7(a)). However, with use of the chemically activated composite (B2B), PB (7.8 +/- 3.6(b) MPa) showed significantly lower dentin bond strengths than OS (32.2 +/- 7.6(a)). Conclusion: the low pH of the adhesive system can affect the bond of chemically activated composite to dentin. on the other hand, under the present conditions, the low pH did not seem to affect the bond of light-activated composites to dentin significantly.

One-year clinical performance of self-etch adhesives in posterior restorations

Purpose: To evaluate the 1-year clinical performance of three self-etching adhesives (Adper Prompt L-Pop, Clearfil S-3 Bond, iBond) in posterior composite restorations using one etch&rinse adhesive (One-Step Plus) as control. Methods: Upon approval by the Institutional Review Board, 121 restorations were inserted in 38 subjects. The adhesives were applied as per manufacturers' instructions. Preparations were restored with a nanofilled resin composite (Filtek Supreme) and evaluated at baseline, 6 months, and 1 year. Statistical analyses included the Chi-square distribution with the McNemar non-parametric test (P< 0.05). Results: At 1 year, 111 restorations in 35 subjects were evaluated using the USPHS modified criteria. No significant changes were observed for the etch&rinse adhesive One-Step Plus. At 1 year the number of Alfa ratings decreased significantly for Clearfil S-3 Bond and for iBond in the categories color match, marginal staining, and marginal adaptation. For Adper Prompt L-Pop, marginal adaptation at 1 year was significantly worse than at baseline. Postoperative sensitivity to air improved significantly for Adper Prompt L-Pop, Clearfil S-3 Bond, and iBond. When the evaluation criteria were paired at 1 year, iBond resulted in a significantly lower number of Alfa ratings than any of the other adhesives for color match, marginal staining, and marginal adaptation. One-Step Plus resulted in a greater number of Alfa ratings for marginal adaptation than either Adper Prompt L-Pop or Clearfil S-3 Bond. Marginal adaptation was significantly better for Clearfil S-3 Bond than for Adper Prompt L-Pop. The post-operative sensitivity measured at 1 year for Adper Prompt L-Pop was statistically better than that for One-Step Plus.

Interaction between total-etch and self-etch adhesives and conventional and self-adhesive resin cements

The aim of this study was to compare the bond strength to enamel between resin cements combined with total-etch and self-etch adhesive systems and a self-adhesive cement. Eighty bovine incisors had their buccal surface ground flat exposing a plane area in the enamel. Eighty Artglass resin cylinders measuring 3 mm in diameter and 4 mm in height were fabricated. The teeth were divided into eight groups of 10 teeth each and the resin cylinders were cemented with different adhesive systems and resin cements; G1: RelyX Unicem (self-adhesive cement); G2: H 3PO 4 + Single Bond + RelyX ARC; G3: AdheSE + Variolink II; G4: H 3PO 4 + Excite + Variolink II; G5: Xeno III + Enforce; G6: H 3PO 4 + Prime&Bond NT + Enforce; G7: Biatite Primers 1 and 2 + Bistite II DC; G8: H 3PO 4 + Bistite Primers 1 and 2 + Bistite II DC. After application of the adhesives, the cylinders were cemented according to manufacturer instructions. The specimens were submitted to 2000 thermal cycles at a temperature ranging from 5±5°C to 55±5°C, and shear bond strength was then tested at a variety of 1 mm/min. The data were analyzed by ANOVA and the Tukey's test (á=5%), obtaining a p value of 0.00. The following mean (±standard deviation) bond strength values were observed for each group: G1: 5.14(±0.99)a; G3: 16.23(±4.69)b; G7: 17.82(±3.66)b; G5: 18.48(±2.88)bc; G8: 20.15(±4.12)bc; G4: 22.85(±3.08)cd; G2: 24.96(±2.89)d; G6: 26.07(±1.69)d. Groups followed by the same letters did not differ significantly. For most of the resin cements tested, the application of adhesive systems using acid etching resulted in a higher bond strength when compared to the self-etch adhesive systems and to the self-adhesive cement.

Using the self-etch adhesives in anterior restoration

With the arrival of self-etch adhesives systems, there has been a rise in interest among clinicians, making it imperative for health professionals to have knowledge of the properties, characteristics, the association as well as the dental structures of these materials, in order to select them and use them correctly. The self-etch adhesive systems show good values of bond strength, microleakage and performance, and have therefore become an option in direct adhesive restorations. In the regard, this case study aims to describe the technique involving the use of selfetch adhesives system for direct restoration of anterior teeth.

Bionanocomposites from electrospun PVA/pineapple nanofibers/Stryphnodendron adstringens bark extract for medical applications

Tissue engineering has been defined as an interdisciplinary field that applies the principles of engineering and life sciences for the development of biological substitutes to restore, maintain or improve tissue function. This area is always looking for new classes of degradable biopolymers that are biocompatible and whose activities are controllable and specific, more likely to be used as cell scaffolds, or in vitro tissue reconstruction. In this paper, we developed a novel bionanocomposite with homogeneous porous distribution and prospective natural antimicrobial properties by electrospinning technique using Stryphodedron barbatimao extract (Barbatimão). SEM images showed equally distribution of nanofibres. DSC and TGA showed higher thermal properties and change crystallinity of the developed bionanocomposite mainly because these structural modification. © 2012 Elsevier B.V.