Universal adhesive: the effect of different simulated pulpal pressure fluids and bonding modes to dentin.

The aim of this study was to evaluate the effect of SPP with either fetal bovine serum (FBS) or deionized water (DW) on the bond strength (µTBS) of a Universal adhesive to dentin, in both etch-and-rinse (ER) and self-etch (SE) modes. The kinematic viscosity (cSt) of FBS and DW was measured at 25 °C ± 0.1 ºC. Seventy-two sound human molars were sectioned and randomly divided into three groups according to the SPP conditions: (1) Control (0 cm H2O), (2) SPP (15 cm H2O) with FBS, (3) SPP (15 cm H2O) with DW. Each group was subdivided (n = 10) based on the bonding modes: ER (37% phosphoric acid + ScothBond Universal Adhesive) or SE (ScothBond Universal Adhesive). Samples were then submitted to µTBS. Data were analyzed by Student's t test, two-way ANOVA and Tukey tests (p < 0.05). The cSt results showed that DW (23.59 ± 0.39) had significantly higher values than FBS (22.33 ± 0.06). With regard to SPP, the control group (36.1 MPa) had significantly higher values of µTBS when compared to the SPP using FBS (31.06 MPa) and SPP with DW (26.55 MPa). According to ANOVA, the bonding modes and the interaction of simulated pulpal pressure (SPP) did not statistically influence the results (p < 0.05). The presence of SPP reduced the bond strength of Universal adhesive to dentin. DW during SPP had significantly reduced bonding values when compared to FBS. Bonding strategies were not affected by SPP when evaluated in a short period of time (24 h).

Clinical performance of topical sodium fluoride when supplementing carbamide peroxide at-home bleaching gel.

This clinical study evaluated the use of 0.11% topical sodium fluoride (SF) desensitizing agent to treat tooth sensitivity during a nightguard tooth whitening procedure. Thirty-two subjects bleached their teeth with 10% carbamide peroxide (CP) gel using an at-home bleaching technique with custom trays. During bleaching treatment, subjects were divided into 2 groups (n = 16). The subjects in Group 1 received a topical gel containing 0.11% SF; the subjects in Group 2 received a placebo gel (PG). Each subject was instructed to place the gel in his/her bleaching tray for 30 min every day following bleaching treatment. Results showed the use of SF did not affect the whitening efficacy of the 10% CP gel. Subjects who received the PG had significantly higher tooth sensitivity when compared with subjects who received SF (P < 0.00). The use of daily 0.11% SF after 10% CP bleaching gel reduced tooth sensitivity during the bleaching treatment.

Grander system: a new technology to reduce surface tension of adhesive systems in dentistry.

BACKGROUND: Reduced surface tension of liquids results in higher surface wetting ability and diffusivity by the substrate. OBJECTIVES: The objective of this study was to evaluate the influence of the Grander Technology in reducing the surface tension of adhesive systems. METHODS: Two adhesive systems (self-etch and total-etch) were modified by physical contact with the Grander system Flexible unit to revitalize water, for 48 h. Surface tension of adhesive systems and water in normal and grander-modified conditions was measured with a goniometer. RESULTS: The results showed a reduction of surface tension for all conditions grander-modified between 3-15%. CONCLUSIONS: Grander Technology was effective in reducing the surface tension of the Single Bond and Clearfil SE Bond adhesive systems. Clinical significance. Grander technology was employed to restructure the molecular structure of water-based adhesive systems, which can increase their wetness capacity and therefore ensure a greater diffusibility.

Bond strength of adhesive systems with different solvents to dry and wet dentin.

AIM: This study evaluates bond strength between dentin and composite using adhesives with different solvents to dry and wet dentin. MATERIALS AND METHODS: Ninety bovine incisors were used; the vestibular surfaces were worn by the exposure of an area with a diameter of 4 mm of dentin. The specimens were divided into 6 groups, according to the type of adhesive used and hydratation stals: Group SB-wet: Single Bond 2 in wet dentin, Group SBdry: Single Bond 2 in dry dentin, Group SL-wet: Solobond M in wet dentin, Group SL-dry: Solobond M in dentin dry. Group XPwet: XP Bond in wet dentin, Group XP-dry: XP Bond in dentin dry. They were cut to obtain specimens in the shape of stick with 1 × 1 mm and subjected to microtensile test in universal testing machine with a cross speed of 1mm/min. The data were analyzed with ANOVA and Tukey's tests (5%). RESULTS: ANOVA showed significant differences for surface treatment and interaction, but no difference was found for adhesive factor. The Tukey's test showed that the samples with wet dentin shown higher values of bond strength. CONCLUSION: The adhesive did not influence in the bond strength. The groups with wet dentin showed higher values of bond strength than groups with dry dentin.

Influence of CVD diamond tips and Er:YAG laser irradiation on bonding of different adhesive systems to dentin.

AIM: The aim of this study was to compare the microtensile bond strength of three adhesive systems, using different methods of dentin preparation. MATERIALS AND METHODS: A hundred and eight bovine teeth were used. The dentin from buccal face was exposed and prepared with three different methods, divided in 3 groups: Group 1 (DT)- diamond tip on a high-speed handpiece; Group 2 (CVD)-CVD tip on a ultrasonic handpiece; Group 3 (LA)-Er: YAG laser. The teeth were divided into 3 subgroups, according adhesive systems used: Subgroup 1-Adper Single Bond Plus/3M ESPE (SB) total-etch adhesive; Subgroup 2-Adper Scotchbond SE/3M ESPE (AS) selfetching adhesive; Subgroup 3-Clearfil SE Bond/Kuraray (CS) selfetching adhesive. Blocks of composite (Filtek Z250-3M ESPE) 4 mm high were built up and specimens were stored in deionized water for 24 hours at 37°C. Serial mesiodistal and buccolingual cuts were made and stick-like specimens were obtained, with transversal section of 1.0 mm(2). The samples were submitted to microtensile test at 1 mm/min and load of 10 kg in a universal testing machine. Data (MPa) were subjected to ANOVA and Tukey's tests (p < 0.05). RESULTS AND CONCLUSION: Surface treatment with Diamond or CVD tips associated with Clearfil SE Bond adhesive produced significantly lower bond strength values compared to other groups. Surface treatment with Er: YAG laser associated with Single Bond Plus or Clearfil SE Bond adhesives and surface treatment with CVD tip associated with Adper Scotchbond SE adhesive produced significantly lower bond strength values compared to surface treatment with diamond or CVD tips associated with Single Bond Plus or Adper Scotchbond SE adhesives. CLINICAL SIGNIFICANCE: Interactions between laser and the CVD tip technologies and the different adhesive systems can produce a satisfactory bonding strength result, so that these associations may be beneficial and enhance the clinical outcomes.

Evaluation of the cohesive strength between resin composite and light-curing characterizing materials.

PURPOSE: To evaluate the cohesive strength between composite and different light-curing characterizing materials (LCCM), which were prepared using the intrinsic technique. MATERIALS AND METHODS: One hundred composite specimens were made by using a prefabricated Teflon device, and a layer of LCCM was applied at the interface. The specimens were divided into 5 groups (n = 20): group 1 (control), no LCCM was used; group 2: application of White Kolor Plus Pigment (Kerr) LCCM; group 3: White Tetric Color Pigment (Ivoclar/Vivadent) LCCM; group 4: Brown Kolor Plus Pigment (Kerr) LCCM; group 5: Black Tetric Color Pigment (Ivoclar/Vivadent) LCCM. All materials were used according to the manufacturers' instructions. Specimens were submitted to a tensile test in a universal testing machine (EMIC DL-200MF) to evaluate the cohesive strength at the composite interface. Data were subjected to one-way ANOVA and Tukey's test (α = 5%). RESULTS: ANOVA showed a p-value = 0.0001, indicating that there were significant differences among the groups. The mean values in MPa (± standard deviation) obtained for the groups were: G1: 28.5 (± 2.74)a; G2: 23.5 (± 2.47)b; G3: 20.3 (± 2.49)b; G4: 10.5 (± 2.40)c; G5: 9.66 (± 3.06)c. The groups with the same letters presented no significant differences. The control group presented statistically significantly higher cohesive strengths when compared to the other groups. The groups in which Brown Kolor Plus Pigment and Black Tetric Color Pigment LCCM were used showed significantly lower cohesive strengths when compared to the groups in which White Kolor Plus Pigment and White Tetric Color Pigment LCMM were used. CONCLUSION: The use of LCCM produced with the intrinsic technique reduced the cohesive strength of composite.

Linear dimensional accuracy of stereolithographic surgical guide after chemistry and physics sterilization.

OBJECTIVES: The purpose of this study was to evaluate the dimensional stability of prototyped surgical guides after autoclave and 2% glutaraldehyde sterilization processes. MATERIAL AND METHODS: Twenty prototyped surgical guides were prepared and submitted to two sterilization processes (n = 10): Physics - sterilization by autoclave (saturated water vapor under pressure, temperature of 126 to 130 °C, pressure of 1,7 at 1.9 kgf/cm2, 16 min); Chemistry - sterilization by 2% glutaraldehyde for 10 h. Six pre-established points were measured in the prototyped surgical guides, before and after sterilization, using a digital caliper rule. The comparisons were made using orthogonal contrasts using the linear model of mixed effects (random and fixed). RESULTS: there are no significant differences between autoclave and glutaraldehyde 2% (p>0.05) there are significant differences after autoclave sterilization (p<0.05) and there are not significant differences after 2% glutaraldehyde sterilization (p>0.05). CONCLUSION: autoclave promoted dimensional alteration of the prototyped surgical guides, and the chemical sterilization by glutaraldehyde 2% did not cause dimensional alteration of the prototype surgical guides, being a favorable choice for sterilization. CLINICAL SIGNIFICANCE: the sterilization of surgical guides can be performed through the chemical process with 2% glutaraldehyde without changing the linear precision of the prototype surgical guides.

Influence of chlorhexidine, propolis, pulpal pressure simulation, and aging on dentin bond strength.

The present study evaluated the bond strength (µTBS) of dentin treated with chlorhexidine and propolis subjected to simulated pulpal pressure (SPP) and thermocycle aging. One hundred and twenty healthy human molars were sectioned to obtain 2 mm of dentin thickness and were divided into two groups (n = 60): SPP (15 cm H2 O) and no SPP (Control group). Dentin surfaces were conditioned with 37% phosphoric acid for 15 s and were divided according to the dentin treatment (n = 20): Control; Chlorhexidine gluconate (0.2% for 30 s) and Propolis (aqueous propolis extract for 30 s). Half of the specimens were submitted to 15,000 thermocycle aging (5 ± 2°C and 55 ± 2°C). The samples were sectioned into beams and submitted to µTBS. Data were analyzed by three-way ANOVA (SPP × Dentin treatment × Thermocycle aging) and the Tukey's tests (p < .001). With regard to the SPP, ANOVA revealed that the Control group (32.98 MPa) had significantly higher values of µTBS when compared to the SPP (29.19 MPa). With regard to Thermocycle aging, no aging (34.05 MPa) had significantly higher values of µTBS when compared to the aging (28.12 MPa). With regard to the dentin treatment, Propolis and Chlorhexidine did not statistically influence the results (p > .05). The SPP and thermocycle aging negatively influenced the bond strength between the dentin and resin; the 0.2% chlorhexidine digluconate and aqueous propolis extract solutions did not interfere in the bond strength between the resin and dentin. The use of chlorhexidine and propolis as a dental treatment may not influence the dentin bond strength, but SPP and thermocycle aging may damage the longitudinal dentin bond strength. RESEARCH HIGHLIGHTS: Chlorhexidine and propolis as a dental treatment may not influence the dentin bond strength. Simulated pulpal pressure and thermocycle aging may damage the longitudinal dentin bond strength.

How Water Content Can Influence the Chemomechanical Properties and Physical Degradation under Aging of Experimental Adhesives.

Objective: To evaluate the physicochemical (sorption (SOR), solubility (SOL), and degree of conversion (DC)) and mechanical (flexural strength (FS), modulus of elasticity (ME), and compressive strength (CS)) properties of adhesives with different water contents (D2O). Materials and Methods: An adhesive was formulated: 55 wt% BisGMA, 45 wt% HEMA, 0.5 wt% camphorquinone, 0.5 wt% EDMAB, and 1.0 wt% DPIHP. D2O was added into the adhesives (0 wt%, 10 wt%, and 16 wt%). DC was monitored through the FTIR. FS, ME, CS, SOR, and SOL were tested. The adhesive samples were aged in deionized water, ethanol, and acetone. Data were submitted to ANOVA and Tukey's tests (5%). Results: For DC, the 0 wt% group showed a significant reduction (68.09 ± 0.14A) compared with the 10 wt% (87.07 ± 0.81B) and 16 wt% groups (89.87 ± 0.24B); 10 wt% showed the highest FS (MPa) mean values (141.6 ± 6.71B) compared with the 0 wt% (109.4 ± 20.5A) and 16 wt% (107.8 ± 15.8A). For the CS (MPa) and ME (GPa), the 16 wt% showed the lowest mean values (98.8 ± 18.0B and 2.2 ± 0.3B, respectively) compared with the 10 wt% and 0 wt%. For the SOR, 16 wt% of water showed the highest mean values and the ethanol showed the lowest mean values of SOL regardless of water content. Conclusion: The amount of water content and the types of aging solvents significantly affect the adhesive properties.

Evaluation of bond strength of self-adhesive cements to dentin with or without application of adhesive systems.

PURPOSE: To evaluate the bond strength of indirect restorations to dentin using self-adhesive cements with and without the application of adhesive systems. MATERIAL AND METHODS: Seventy-two bovine incisors were used, in which the buccal surfaces were ground down to expose an area of dentin measuring a minimum of 4 x 4 mm. The indirect resin composite Resilab was used to make 72 blocks, which were cemented onto the dentin surface of the teeth and divided into 4 groups (n = 18): group 1: self-adhesive resin cement BiFix SE, applied according to manufacturer's recommendations; group 2: self-adhesive resin cement RelyX Unicem, used according to manufacturer's recommendations; group 3: etch-and-rinse Solobond M adhesive system + BiFix SE; group 4: etch-and-rinse Single Bond 2 adhesive system + RelyX Unicem. The specimens were sectioned into sticks and subjected to microtensile testing in a universal testing machine (EMIC DL- 200 MF). Data were subjected to one-way ANOVA and Tukey's test (α = 5%). RESULTS: The mean values (± standard deviation) obtained for the groups were: group 1: 15.28 (± 8.17)a, group 2: 14.60 (± 5.21)a, group 3: 39.20 (± 9.98)c, group 4: 27.59 (± 6.57)b. Different letters indicate significant differences (ANOVA; p = 0.0000). CONCLUSION: The application of adhesive systems before self-adhesive cements significantly increased the bond strength to dentin. In group 2, RelyX Unicem associated with the adhesive system Single Bond 2 showed significantly lower mean tensile bond strengths than group 3 (BiFix SE associated with the etch-and-rinse Solobond M adhesive system).

The influence of chemical activation on tooth bleaching using 10% carbamide peroxide.

The aim of this study was to assess the influence of manganese gluconate, a chemical activator of bleaching agents, at a concentration of 0.01% on the efficiency of a 10% carbamide peroxide-based bleaching agent. Forty bovine incisors were immersed in a 25% instant coffee solution for seven days and randomly divided into two groups. Group 1 was the control group and consisted of 10% carbamide peroxide-based bleaching gel only. Group 2 consisted of 10% carbamide peroxide-based bleaching gel and 0.01% manganese gluconate. Three readings of color were taken using the Vita Easyshade spectrophotometer: the initial reading, a reading at seven days, and a reading at 14 days. Total color variation was calculated by ΔE*Lab. Data were submitted to the statistical t-test (5%), which showed that after seven days group 2 had a significant increase in the degree of tooth bleaching compared with group 1. The mean values (±SD) were 16.33 (±3.95) for group 1 and 19.29 (±4.97) for group 2. However, the results for group 1 and group 2 were similar after 14 days. Adding 0.01% manganese gluconate to 10% carbamide peroxide bleaching gel increased the degree of tooth bleaching after a seven-day treatment and did not influence the resulting shade after 14 days.

Assessment of the effectiveness of light-emitting diode and diode laser hybrid light sources to intensify dental bleaching treatment.

OBJECTIVE: To evaluate the effectiveness of the color change of hybrid light-emitting diode (LED) and low-intensity infrared diode laser devices for activating dental bleaching and to verify the occurrence of a color regression with time. MATERIAL AND METHODS: A total of 180 specimens obtained from human premolars were immersed in a coffee solution for 15 days for darkening and then divided into eight experimental groups (n = 20 in each) as follows: G1, bleaching without light; G2, bleaching with halogen light; G3, bleaching with a blue LED (1000 mW/470 nm) and a laser device (120 mW/795 nm) simultaneously; G4, bleaching with an LED emitting blue light (1000 mW/470 nm); G5, bleaching with a blue LED (800 mW/470 nm) and a laser device (500 mW/830 nm) simultaneously; G6, bleaching with a blue LED device (800 mW); G7, bleaching with a green LED (600 mW/530 nm) and a laser device (120 mW/795 nm) simultaneously; and G8, bleaching with a green LED (600 mW). Three measurements were performed (at baseline and 14 days and 12 months after bleaching) using a Vita Easyshade spectrophotometer. The data were submitted to two-way ANOVA and a Tukey test. RESULTS: All groups showed significantly higher ΔE values than Group G1, with the exception of Group G8. Variations in the ΔE values at 14 days were significant when compared with those obtained at baseline and after 12 months. CONCLUSIONS: Light activation of the bleaching gel provided faster and more intense bleaching than use of the bleaching gel without light activation. Combinations of low-intensity diode lasers are ineffective as a bleaching gel activator. Color regression was observed after 12 months of storage.

pH-changes during intracoronal bleaching: an in vivo study.

OBJECTIVES: This study aimed to measure pH changes during 14 days intracoronal bleaching with hydrogen peroxide/sodium perborate and carbamide peroxide/sodium perborate. MATERIALS AND METHODS: Twenty patients presenting endodontically treated central maxillary incisors with color alterations were divided in two groups (n = 10): Group CP + SP: 37% carbamide peroxide + sodium perborate paste; Group HP + SP: 30% hydrogen peroxide + sodium perborate paste. The pH values were measured using a digital microprocessor at different times: Baseline, 2, 7 and 14 days. Data were analyzed with two-way ANOVA followed by Tukey's test (α = 0.05). RESULTS: ANOVA showed p < 0.00 which indicated significant difference between the groups. The mean values (± sd) and the results of the Tukey´s test were: HP + SP/14 days-7.98 (±0.58)a; HP + SP/7 days-8.59 (±0.18)b; HP + SP/2 days- 8.83 (±0.32)bc; HP + SP/Baseline-8.83 (±0.01)bc; CP + SP/ Baseline-8.89 (±0.01)bc; CP + SP/14 days-9.11 (±0.58)cd; CP + SP/7 days-9.54 (±0.16)de; CP + SP/2 days-9.66 (±0.08) de. The group HP + SP resulted in significantly lower pH values compared with group CP + SP. CONCLUSION: It can be concluded that both associations showed alkaline pH values; however, there was significant reduction in the pH values of the 30% hydrogen peroxide associated with sodium perborate after 14 days. CLINICAL SIGNIFICANCE: The association of hydrogen peroxide and carbamide peroxide with sodium perborate paste presented alkaline characteristics during the 14-day evaluated period. Thus, regarding pH changes, both associations can be considered safe as intracoronal bleaching agents.

Prevalence of chewing side preference in the deciduous, mixed and permanent dentitions.

AIM: This study evaluated the prevalence of the chewing side preference (CSP) in the deciduous, mixed and permanent dentitions. MATERIALS AND METHODS: Three-hundred subjects were divided in three groups (n = 100): Group 1 - children with deciduous dentition; group 2-children with mixed dentition; group 3 - subjects with permanent dentition. The CSP was determined using a direct method (visual observation) developed by McDonnell et al. (2004). Descriptive statistic was used to observe the prevalence of CSP. The Pearson's Chi-square was used to investigate signicant associations between gender, presence of CSP and preferred side (right/left). RESULTS AND CONCLUSION: Eighty-seven percent of group 1 had a CSP. Eighty-two percent of group 2 had a CSP. Seventy-six percent of group 3 had a CSP. There was no statistically significant association between presence of CSP and gender in all groups. There was no statistically significant association between preferred side (right/left) and gender in all groups. CLINICAL SIGNIFICANCE: There is a higher prevalence of subjects in deciduous, mixed and permanent dentition that presented chewing side preference. The early diagnosis of the presence of chewing side preference can prevent the unilateral chewing pattern with prophylactic therapy applied to the first teeth (deciduous).

Effect of carbamide peroxide bleaching gel concentration on the bond strength of dental substrates and resin composite.

PURPOSE: This study evaluated the effect of bleaching gel containing 10%, 15% and 20% carbamide peroxide (CP) on the bond strength of dental enamel or dentin and resin composite restorations. METHODS: The buccal surfaces of 12 bovine tooth crowns were conditioned with 37% phosphoric acid, and the adhesive resin Single Bond 2 and the resin composite Filtek Z350 were used to perform the restorations. The blocks were sectioned to obtain bar specimens. Each specimen group (enamel-E, dentin-D) was divided into four subgroups (n=15): S-artificial saliva; 10-10% CP bleaching; 15-15% CP bleaching; 20-20% CP bleaching. CP was applied for six hours daily for two weeks. The specimens were submitted to the sigma test in a universal testing machine. The data were analyzed by one-way ANOVA and the Tukey post-hoc test and a correlation analysis (r) was performed. RESULTS: For Group E, the mean value (+/- standard-deviation) was 21.86 (+/- 6.03)a, 18.91 (+/- 8.31)ab, 15.43 (+/- 7.44)b and 10.6 (+/- 4.94)c for ES, E10, E15 and E20, respectively. For Group D, the a values were 34.73 (+/- 4.68)a, 35.12 (+/- 13.43)a, 29.67 (+/- 6.84)ab and 24.56 (+/- 6.54)b for DS, D10, D15 and D20, respectively. A negative correlation between the CP concentration and mean values was observed for both the enamel (r=-0.95) and dentin (r=-0.85) groups. CONCLUSION: In the current study, the bond strength of the restoration to enamel and the restoration to dentin were influenced by the application of CP and was dependent on the CP concentration in the bleaching gel.

In vitro assessment of chemical activation efficiency during in-office dental bleaching.

PURPOSE: This study compared five types of chemical catalyzing agents added to 35% hydrogen peroxide gel, with regard to their capacity of intensifying in-office dental bleaching results. METHODS: One-hundred and twenty bovine incisors were used, of which the crowns and roots were cut in the incisor-apical direction, to acquire the dimensions of a human central incisor. The specimens were sectioned in the mesiodistal direction by means of two longitudinal cuts, the lingual halves being discarded. The vestibular halves received prophylaxis with a bicarbonate jet, ultrasound cleaning and acid etching on the dentinal portion. Next, the specimens were stored in receptacles containing a 25% instant coffee solution for two weeks. After the darkening period, initial measurement of the shade obtained was taken with the Easy Shade appliance, which allowed it to be quantified by the CIELab method. The samples were divided into six groups, corresponding to the chemical activator used: a) none (CON); b) ferric chloride (CF); c) ferrous sulphate (SF); d) manganese gluconate (GM); e) manganese chloride (CM); f) mulberry root extract (RA). Each group received three 10-minute applications of the gels containing the respective activating agents. Next, a new shade measurement was made. RESULTS: The Analysis of Variance and Tukey tests (alpha = 5%) showed statistically significant differences for the shade perception values (p = 0.002). Groups GM, CM and RA showed significantly higher means than the control group. CONCLUSION: The presence of some chemical activators is capable of resulting in a significant increase in tooth shade variation.

Assessment of color fidelity of several composite resins compared to their Vita Classical shade registration.

This study compared the color fidelity of different composite resins with their registration in the Vita Classical Shade Guide. Using a prefabricated Teflon mold, 120 specimens were divided into four groups (n = 30), according to the resin tested. Three subgroups (n = 10) were prepared for each resin group; these subgroups tested enamel shade, dentin shade, and enamel and dentin shade. Three measurements were performed to verify whether the tooth shade matched that of the Vita Classical Shade Guide. The color was evaluated and the shade variations were calculated. The data were submitted to a three-way ANOVA test (time, color match, and composite type), followed by Tukey's test. It was concluded that all composite resins showed color differences in relation to the Vita Classical Shade Guide.

Clinical evaluation of two packable resin-based composite restorations: a three-year report.

This randomized clinical trial sought to evaluate the performance of two packable composites over a period of 36 months. A total of 39 Class I and II restorations were placed in the permanent teeth of 20 patients. Using United States Public Health Services criteria, two investigators evaluated the restorations immediately after placement and again after 12 and 36 months, examining color match, marginal discoloration, marginal integrity, recurrent caries, proximal contact, anatomical shape, surface texture, and postoperative sensitivity. It was concluded that the packable composites evaluated showed satisfactory clinical performance after three years.

Influence of methods of application of self-etching adhesive systems on adhesive bond strength to enamel.

PURPOSE: To assess the influence of variations in the application technique of self-etching adhesive systems on the adhesive bond strength to enamel. MATERIALS AND METHODS: One hundred thirty bovine teeth were used and divided into 13 groups. The teeth were embedded in acrylic resin, ground until a flat enamel area was exposed, and polished with 600-grit abrasive paper. The self-etching adhesive systems One Up Bond F, Clearfil SE Bond, Self & Etch were used, and the conventional adhesive Magic Bond and acid etching were used as the control group. One or two layers of the self-etching systems were actively or passively applied. Composite cylinders were made over the bonding area. The samples were submitted to shear bond testing at a speed of 1 mm/min. Statistical analysis of the data was performed using two-way ANOVA, followed by Tukey's test at a 5% level of significance. RESULTS: Significant variations were observed for the factors type of adhesive (p = 0.001, F = 193,3594, df = 3) and application technique (p = 0.001, F = 29,9119, df = 1). No significant interaction was found between the two factors (p = 0.08). The adhesives Clearfil SE Bond and One Up Bond F presented significantly higher adhesive bond strength means than Self & Etch. The active application of two layers resulted in higher bond strength means than the other techniques. CONCLUSION: The application technique had a significant influence on adhesive bond strength to enamel.

Longitudinal bond strength evaluation using the deproteinized dentin technique.

This study evaluated bond strength to dentin as a result of storage time for conventional adhesive systems (with or without collagen) that had been deproteinized with 10% sodium hypochlorite (NaOCl). For this study, 72 human molars were sectioned in a mesiodistal axial plane and embedded in acrylic resin; at that point, the vestibular and lingual surfaces were worn down with abrasive paper. Acid etching was performed for 15 seconds (using 37% phosphoric acid) and the specimens were divided into 12 groups (n = 6), depending on the adhesive system used, the dentin treatment performed, and the length of evaluation (24 hours or six months). A resin composite was inserted over the prepared area with the aid of a metal matrix. Following a mechanical shear test, fractured surfaces were analyzed by stereomicroscope and the data were submitted to ANOVA and Tukey's test. It was concluded that the dentin deproteinization treatment with 10% NaOCl improved the bond strength in five of the six groups. The bond strength after 24 hours was significantly higher than the bond strength measured after six months. Of the three adhesive systems tested in this study, DenTASTIC UNO demonstrated the lowest bond strength.