Self-etch Group Research Articles

Bond strength of repaired composite resins: surface treatments, adhesive systems, and composite type

The aim of the present study was to investigate the effects of three different surface treatments and two different adhesives on the microtensile bond strength (μTBS) of repaired composites using the same or different type of resin. Twenty-four nano-hybrid (Ceram X mono-C) and 24 nanofilled (Filtek Ultimate-F) composite discs were prepared. The specimens were aged with 5000 thermocycles and randomly divided into groups according to the surface treatment methods: (a) phosphoric acid (b) Er:YAG laser and (c) aluminum trioxide particle (air abrasion). Fresh composite resins (C and F) were added to the treated surfaces with two different adhesives (two-step and one-step self-etch adhesives). Then, the specimens were aged again. The stick-shaped specimens were prepared from the discs (n = 25) and the sticks were subjected to the μTBS test. Results indicated that significant differences were found in μTBS values among the surface treatment methods. In the C groups, the highest μTBS value (41.3 ± 8.3 MPa) was recorded in the air abrasion and one-step self-etch adhesive group, which were repaired with the same kind of composite. In the F groups, the highest μTBS value was observed in the air abrasion and one-step self-etch adhesive (37.6 ± 12.3 MPa) group. The treatment with air abrasion is more effective than the others, and it may be suggested for composite repair.

The effect of saliva decontamination procedures on dentin bond strength after universal adhesive curing.

ObjectivesThe purpose of this study was to investigate the effectiveness of multiple decontamination procedures for salivary contamination after curing of a universal adhesive on dentin bond strength according to its etch modes.Materials and MethodsForty-two extracted bovine incisors were trimmed by exposing the labial dentin surfaces and embedded in cylindrical molds. A universal adhesive (All-Bond Universal, Bisco) was used. The teeth were randomly divided into groups according to etch mode and decontamination procedure. The adhesive was applied according to the manufacturer's instructions for a given etch mode. With the exception of the control groups, the cured adhesive was contaminated with saliva for 20 sec. In the self-etch group, the teeth were divided into three groups: control, decontamination with rinsing and drying, and decontamination with rinsing, drying, and adhesive. In the etch-and-rinse group, the teeth were divided into four groups: control, decontamination with rinsing and drying, decontamination with rinsing, drying, and adhesive, and decontamination with rinsing, drying, re-etching, and reapplication of adhesive. A composite resin (Filtek Z350XT, 3M ESPE) was used for filling and was cured on the treated surfaces. Shear bond strength was measured, and failure modes were evaluated. The data were subjected to one-way analysis of variation and Tukey's HSD test.ResultsThe etch-and-rinse subgroup that was decontaminated by rinse, drying, re-etching, and reapplication of adhesive showed a significantly higher bond strength.ConclusionsWhen salivary contamination occurs after curing of the universal adhesive, additional etching improves the bond strength to dentin.

Influence of erbium, chromium-doped: Yttrium scandium-gallium-garnet laser etching and traditional etching systems on depth of resin penetration in enamel: A confocal laser scanning electron microscope study.

Objective:This study was performed to assess the resin tag length penetration in enamel surface after bonding of brackets to identify which system was most efficient.Methodology:Our study was based on a more robust confocal microscopy for visualizing the resin tags in enamel. Totally, 100 extracted human first and second premolars have been selected for this study and were randomly divided into ten groups of 10 teeth each. In Group 1, the buccal enamel surface was etched with 37% phosphoric acid (3M ESPE), Group 2 with 37% phosphoric (Ultradent). In Groups 5, 6, and 7, erbium, chromium-doped: Yttrium scandium-gallium-garnet (Er, Cr: YSGG) laser (Biolase) was used for etching the using following specifications: Group 5 (1.5 W/20 Hz, 15 s), Group 6 (2 W/10 Hz, 15 s), and Group 7 (2 W/20 Hz, 15 s). In Groups 8, 9, and 10, Er, Cr: YSGG laser (Biolase) using same specifications and additional to this step, conventional etching on the buccal enamel surface was etched with 37% (3M ESPE) after laser etching. In Groups 1, 5, 6, 7, 8, 9, and 10 3M Unitek Transbond XT primer was mixed with Rhodamine B dye (Sigma-Aldrich, Germany) to etched surface and then cured for 20 s. In Group 2, Ultradents bonding agent was mixed with Rhodamine B. In Group 3, 3M Unitek Transbond PLUS, Monrovia, USA, which was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Group 4, with self-etching primer (Ultradent-Peak SE, USA) was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Later (3M Unitek, Transbond XT, Monrovia USA) [Figure 1] was used to bond the modified Begg brackets (T. P. Orthodontics) in Groups 1, 3, 5, 6, 7, 8, 9, and 10. In Groups 2, 4 Ultradent-Peak LC Bond was used to bond the modified brackets. After curing brackets were debonded, and enamel depth penetration was assessed using confocal laser scanning microscope.Results:Group J had a mean maximum depth of penetration of 100.876 μm, and Group D was the least having a maximum value of 44.254 μm.Conclusions:Laser alone groups had comparable depths of penetration to that of self-etching groups but much lower than conventional acid etched groups.

Nanoleakage in indirect composite restorations using different combinations of resin coating technique

Abstract The aim of this study was to evaluate the nanoleakage patterns in indirect composite restorations bonding to dentin using different combinations of Resin Coating, after thermal and load cycling. Twenty five extracted third molars were used in the study; two box-like Class II cavities were prepared in each tooth (mesial and distal surface). The 50 cavities were distributed in 5 groups according to the RC materials combinations: G1: Etch-rinse 2 steps/Hydrophobic monomer; G2: Etch-rinse 2steps/Flow composite-resin, G3: Self-etch 1step, G4: Self-etch1step/Flowable composite resin liner, G5: Self-etch 2step/Flowable composite-resin liner. The cavities were molded with a vinyl polysiloxane impression material and the molds were poured with stone plaster. The fillings were confectioned using the Sinfony composite system (3 M/ESPE) and cemented with resin luting cement (Rely X ARC). After 24 hours, the teeth were submitted to thermocycling (2000 cycles, 5° to 55°C) and load cycling (250,000 cycles, 30 N). Past 24hours, the restored teeth were sectioned into serial slabs and immersed in 50% ammoniacal silver nitrate for 24 h, exposed to photo-developing solution for 8 h, carbon coated and observed in SEM using backscattered electron mode. Diverse nanoleakage patterns were observed for the different RC combinations. Silver accumulation were observed in the entire thickness of the hybrid layer in G1 and G2 groups, while in the “all in one” self-etch groups (G3 and G4) silver accumulations similar to “water trees” within the adhesive layer were observed. In G5 group, less nanoleakage than other groups was observed and it was limited to the hybrid layer. The group G5 presented a superior behavior and revealed less nanoleakage compared to the other groups.

The effect of luting cement thicknesses on the push-out bond strength of the fiber posts

Objective. The aim of this study was to evaluate the effect of luting cement thicknesses on the push-out bond strength of the fiber posts. Materials and methods. Sixty human maxillary canine teeth were endodontically treated. Post spaces were prepared and root specimens randomly divided into three groups: Group 1: etch-and-rinse (Variolink II/Exite DSC), Group 2: self-etch (Panavia F2.0/ED primer) and Group 3: self-adhesive (Clearfil SA Cement). Then each group was divided into four sub-groups according to the cement thickness, as follows: Sub-group 1: 0.35 mm, Sub-group 2: 0.25 mm, Sub-group 3: 0.15 mm, and Sub-group 4: 0.05 mm. Three slices of 1 mm thickness were obtained from each root specimen (n = 15). Push-out tests were performed and data was analyzed with two-way ANOVA and Tukey tests. Results. The etch-and-rinse system (Variolink II) had a significantly higher bond strength compared with the other systems ( p < 0.05). The thickest cement group (0.35 mm) had a significantly lower bond strength compared with the 0.15 and 0.05 mm groups in the etch-and-rinse and self-adhesive groups (p < 0.05). In the self-etch group, the cement thicknesses did not significantly affect the bond strength (p > 0.05). Conclusions. The etch-and-rinse system offered better bonding to root dentine than the self-adhesive and self-etch systems. The increases in cement thickness significantly reduced the bond strength of fiber posts to root dentine for both the etch-and-rinse and self-adhesive systems.

Bond strengths, degree of conversion of the cement and molecular structure of the adhesive–dentine joint in fibre post restorations

ObjectivesBecause fibre post restorations are influenced by multiple factors such as the types of bonding materials, the dentine region and the time under moist exposure, this study sought to determine the bond strength of endodontic restorations and its relation to the degree of conversion of the cement layer and the molecular structure of the dentine-bonded joints. MethodsThe performance of 2 etch-and-rinse (All-Bond 2 and One-Step Plus) and 2 self-etch (Clearfil SE Bond and Xeno III) adhesives at post spaces regions, after 7d or 4m, was evaluated. FRC Postec Plus posts were cemented to the root canal with a dual-cure resin cement (Duo-Link). Transverse sections of the tooth were subjected to push-out testing, to degree-of-conversion measurements and to hybrid layer evaluation through μ-Raman spectroscopy. ResultsCoronal bonding was higher than cervical and middle bonding. The hybrid layer was thicker for the etch-and-rinse systems, with thicknesses decreasing towards the middle region. The degree of conversion measured for the 3-step etch-and-rinse group after 4m was significantly higher than that for the self-etching groups. ConclusionsAlthough not totally stable at the adhesive–dentine interface, the 3-step etch-and-rinse adhesive in the coronal dentine provided the best bond strength, degree of conversion of the cement and hybrid layer thickness in post restorations, in both short- and long-term analyses.

An in vitro evaluation of shear bond strength of silorane and bis-GMA resin-based composite using different curing units

Aim:To evaluate shear bond strength of silorane and bis-GMA based composite resins using self-etch and total-etch adhesive systems, and compare the effect of Quartz-tungten-halogen (QTH) and Light emitting diode (LED) on the shear bond strength of the experimental materials.Materials and Methods:Flat dentin surfaces were exposed on intact extracted molars and composite resin was built 2 mm in diameter. Teeth were divided randomly into four groups. Groups 1 and 2 were restored with P90 system adhesive and Filtek P90 and cured with QTH and LED units respectively. Groups 3 and 4 were restored with total etch adhesive and Filtek Z100 and cured with QTH and LED units respectively. Specimens were subjected to shear bond strength testing using Instrom Universal testing machine.Results:Data was subjected to one-way analysis of variance. Total-etch groups gave significantly higher shear bond strength values than the self-etch groups. No significant difference in shear bond strength was found between Groups 3 and 4, while Group 1 showed significantly higher values than Group 2.Conclusion:Type of light curing unit is not a significant factor affecting shear bond strength for bis-GMA RBCs using total-etch technique; while for curing silorane resin based composite (RBCs), conventional halogen curing units showed better results.

Effect of different adhesion strategies on push-out bond strength of fiber reinforced composite posts

The aim of this study was to compare the bond strength of translucent fiber posts to root dentin, cemented with 4 adhesion strategies. Forty eight (48) sound human central incisors were decoronated and divided into 4 groups: Etch-and-rinse group, two-step self-etch group, one-step self-etch group, and self-adhesive resin cement group. The adhesion between the post and root canal walls was assessed using push-out test. Data was analyzed using one and two way ANOVA and a post hoc Tukey test (P<0.05). There were significant differences in mean bond strength values between the etch-and-rinse group and the other groups (P<0.001). Bond strength in the apical region was significantly different from those of the middle (P = 0.018) and cervical (P = 0.014) regions in etch and rinse group. The results were confirmed by scanning electron microscopy (SEM). Etch and rinse adhesive systems are more effective in bonding of fiber posts to post space dentin. Key words : Adhesive system, bond strength, fiber post, root canal dentin.

Comparison of the effects of Er,Cr:YSGG laser and different cavity disinfection agents on microleakage of current adhesives

The aim of this study was to compare the effect of the Er,Cr:YSGG laser and different cavity disinfection agents on microleakage of an etch-and-rinse and a self-etch adhesive. Class V preparations were completed on the buccal and lingual surfaces of 30 extracted noncarious human molars. The occlusal margin was placed on enamel and the gingival margin on dentin. Preparations were randomly divided into five experimental groups (n = 12); (1) 2% chlorhexidine gluconate (CHX), (2) propolis, (3) ozone, (4) Er,Cr:YSGG laser, and (5) control (no treatment). Each group was divided into two subgroups according to the adhesive system: etch-and-rinse (Adper Single Bond 2), and a self-etch adhesive (All-Bond SE). The preparations were bulk-filled with a resin composite (Arabesk). After storage in distilled water for 24 h the restored teeth were subjected to thermocycling (1,000 cycles; 5-55°C). All specimens were immersed in 0.5% basic fuchsin solution for 24 h and sectioned longitudinally through the centre of the restorations and examined under a stereomicroscope at ×25 magnification. The data were analysed using the Kruskal-Wallis and Mann-Whitney U-tests. No difference was observed between the groups either on enamel or dentin when the etch-and-rinse adhesive was used (p > 0.05). In the self-etch adhesive groups, a significant difference was found only between the laser group and the CHX group on enamel and between the propolis group and the control group on dentin (p < 0.05). Comparing the etch-and-rinse and self-etch adhesives within each group, no differences were found on dentin (p > 0.05). On enamel, a statistically significant difference was found only in the CHX group (p < 0.05). There were no differences in microleakage with the laser and the different cavity disinfectant applications when used with etch-and-rinse adhesive. In the self-etch group there were differences in microleakage depending on the disinfection agent used.

Comparative Evaluation of Shear Bond Strength of Orthodontic Brackets using Laser Etching and Two Conventional Etching Techniques: An in vitro Study

Introduction: The purpose of this study was to evaluate and compare the shear bond strength between the bracket and acid etched enamel, enamel treated with self-etch primer and laser irradiated enamel and to analyze the interface of the enamel bracket bond. Materials and methods: Around 60 noncarious human premolars were divided randomly into three groups of 20 each and etched using 37% phosphoric acid, self-etch primer and Er:YAG laser. Stainless steel brackets were then bonded using Transbond XT following which all the samples were stored in distilled water at room temperature for 24 hours. Shear bond strength was tested using a chisel edge, mounted on the crosshead of Universal Testing Machine. After debonding, the teeth were examined under 10× magnification with a stereomicroscope and ARI score determined. Shear bond strengths of the three groups were then compared using ANOVA test (multiple comparisons, Tukey’s correction). Comparison of the ARI scores was done using Chi-square test. Result: The acid etched group yielded the highest mean debonding force (13.34 Mpa) followed by self-etch group (12.15 Mpa) and laser etch group (12.10 Mpa). No significant difference was found between the three groups. On comparison of the ARI scores, it was found that the adhesive left on the enamel surface after debonding was significantly higher in the acid etched group than the self-etch group (p = 0.009). There was no significant difference in the ARI scores between the other two groups. Conclusion: These results indicate that the shear bond strength of all the three groups was clinically acceptable with no significant difference between them but more adhesive was left on enamel treated with acid and laser as compared to self-etch primer treated enamel.

In vitro evaluation of self-etch bonding in orthodontics using cyclic fatigue

To evaluate the bond strength of a self-etch bonding system using static loading and cyclic fatigue with shear testing. This is a two-part evaluation; the first part will evaluate shear testing, the second part tensile testing. Bovine teeth (n = 82) were randomly distributed to either a self-etch (Transbond Plus) or total-etch (37% phosphoric-acid + Transbond XT) group. The static shear (SSBS) and cyclic shear (CSBS) bond strengths were measured 24 hours after the bonding of mesh-based brackets. The adhesive remnant index (ARI) and failure sites were evaluated. The mean SSBS was 34.25 ± 9.21 and 24.64 ± 9.42 MPa for the total- and self-etch groups, respectively. CSBS was 24.07 ± 0.65 MPa and 18.92 ± 1.08 MPa for the total- and self-etch groups, respectively. Cyclic loading produced lower bond strengths compared to static testing for both adhesives; the difference was only statistically significant for the total-etch system. Comparison of the two materials showed a statistically significant difference between the two techniques. The total-etch had higher bond strengths than the self-etch bonding system. The samples showed a predominance of ARI scored of 2 and 1, and their bonding failure sites were cohesive within the composite. Cyclic loading, simulating occlusal forces, reduces the bond strength of both bonding systems. Even though the self-etch bonding system had lower shear bond strength than the total-etch system, both were still clinically acceptable.

Push-out bond strength of Resilon/Epiphany self-etch and gutta-percha/AH26 after different irrigation protocols

The purpose of this study was to compare the bond strength of Resilon/Epiphany self-etch (SE) and gutta-percha/AH26 after different irrigation protocols. Extracted single-rooted human teeth were divided into 4 groups and prepared. According to irrigation protocols, groups were: 5.25% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA) (groups 1 and 2); and 1.3% NaOCl followed by MTAD (a mixture of tetracycline isomer, an acid, and a detergent) (groups 3 and 4). The root canals were obturated with either gutta-percha/AH26 (groups 1 and 3) or Resilon/Epiphany SE (groups 2 and 4). Push-out bond strength and failure modes were determined. Gutta-percha/AH26 showed significantly higher bond strength than Resilon/Epiphany SE. The group with 5.25% NaOCl + EDTA and gutta-percha had a significantly higher bond strength than all of the other groups (P < .05); 1.3% NaOCl + MTAD with gutta-percha showed significantly higher bond strength than 5.25% NaOCl + EDTA with Resilon and 1.3% NaOCl + MTAD with Resilon. There was no significant difference between the bond strengths of the Resilon groups (P > .05). The failure mode for all of the experimental groups was mainly adhesive. Irrigation with 5.25% NaOCl + EDTA can be a better conditioner before using gutta-percha/AH26. The bond strength of Resilon/Epiphany SE was not different after irrigation with 5.25% NaOCl + EDTA or 1.3% NaOCl + MTAD.

Evaluation of the adhesion of fiber posts cemented using different adhesive approaches

The aim of this study was to investigate the adhesion of fiber posts cemented with luting agents that utilize three currently available adhesive approaches: etch-and-rinse, self-etch, and self-adhesive. Forty-two intact single-rooted human premolars were used in the study. Teeth were divided into six groups. In each group, a different resin cement with its adhesive system (if needed) and a fiber post were used. The groups were classified, according to the adhesive approach, into the following three categories. (i) Etch-and-rinse groups: Calibra resin cement/XPBond adhesive + self-curing activator (SCA)/RadiX Fiber Post (Dentsply Caulk), FluoroCore 2 core build-up material/XPBond + SCA/RadiX Fiber Post (Dentsply Caulk), and MultiCore Flow luting and core build-up material/Excite DSC adhesive/FRC Postec Plus fiber post (Ivoclar Vivadent). (ii) Self-etch group: Panavia F 2.0/ED primer (Kuraray)/RadiX Fiber Post (Dentsply Caulk). (iii) Self-adhesive groups: experimental self-adhesive cement/RadiX Fiber Post (Dentsply Caulk), and RelyX Unicem/RelyX Fiber Post (3M ESPE). The adhesion between the post and the root canal walls was assessed using the 'thin-slice' push-out test. In the test arrangement used, the self-etching approach may offer less favourable adhesion to root canal dentin in comparison with etch-and-rinse and self-adhesive approaches.

Rebonding of Orthodontic Brackets

The hypothesis of this two-part study is that adhesive systems for bonding orthodontic brackets (ie, two self-etch primers [Transbond and M-Bond] and a conventional phosphoric acid etch [Rely-a-Bond]) would show a difference with respect to rebonded enamel surface morphology and chemical composition. This study examined the enamel surface before and after debonding with scanning electron microscopy and the enamel surface chemical composition for the elements Ca, P, O, F, Si, and C using x-ray photoelectron spectroscopy. The etching of the two self-etch groups is less aggressive and less uniform than that of phosphoric acid. The change in the concentration of C indicated that the separation of the bracket from the enamel surface is at the resin-enamel interface for the phosphoric acid-etched adhesive and a mixed mode involving the enamel-resin-bracket interfaces for the self-etching systems. F release appears to occur for Transbond but not for M-Bond. The results confirm the original hypothesis that differences in adhesive systems are manifested in less aggressive etches and less adhesive left on the enamel surface for the self-etching adhesive systems.

Enamel loss during bonding, debonding, and cleanup with use of a self-etching primer

Self-etching primers have recently been introduced to simplify the orthodontic bonding process. The aim of this investigation was to compare the enamel loss at each stage of the bonding and debonding process with the use of such a product compared with the conventional two-stage etching and priming process with 37% o -phosphoric acid. In the laboratory, a planer surfometer was used to measure enamel surface height before any enamel treatment, after pumicing, after etching, and once the brackets had been debonded, after enamel clean-up with one of 4 clean-up methods. The latter included a high-speed tungsten carbide bur, a slow-speed tungsten carbide bur, debanding pliers, and an ultrasonic scaler. A change in enamel surface height was seen at each stage of the bonding and debonding process. After pumicing and conventional etching, the cumulative median enamel loss was -2.76 microm; however, the range was from -1.11 to -4.57 microm. This observed loss was much less than in previous reports on enamel loss after acid etching. With the self-etching primer, the median enamel loss was significantly lower, at -0.27 microm (range, -0.03 to -0.74 microm). At debond, there was also a significant difference in the adhesive remnant index scores between the 2 groups, with more adhesive remaining on the enamel surface in the conventional-etch group. It was during enamel clean-up that most surface loss occurred. In both the conventional and self-etch groups, most enamel loss occurred after the use of the high-speed tungsten carbide bur or the ultrasonic scaler and least with the slow-speed tungsten carbide bur or the debanding pliers.

The etching effects and microtensile bond strength of total etching and self-etching adhesive system on unground enamel

The purpose of this study was to evaluate the etching effects and bond strength of total etching and self-etching adhesive system on unground enamel using scanning electron microscopy and microtensile bond strength test. The buccal coronal unground enamel from human extracted molars were prepared using low-speed diamond saw. Scotchbond Multi-Purpose (group SM). Clearfil SE Bond (group SE), or Adper Prompt L-Pop (group LP) were applied to the prepared teeth. and the blocks of resin composite (Filtek Z250) were built up incrementally. Resin tag formation was evaluated by scanning electron microscopy. after removal of enamel surface by acid dissolution and dehydration. For microtensile bond strength test. resin-bonded teeth were sectioned to give a bonded surface area of . Microtensile bond strength test was perfomed. The results of this study were as follows. 1. A definite etching pattern was observed in Scotchbond Multi-Purpose group. 2. Self-etching groups were characterized as shallow and irregular etching patterns. 3. The results (mean) of microtensile bond strength were SM: 26.55 MPa, SE: 18.15 MPa, LP: 15.57 MPa. SM had significantly higher microtensile bond strength than 8E and PL (p