Self-etching Primer Adhesive System Research Articles

An Investigation into the Use of a Single Component Self-etching Primer Adhesive System for Orthodontic Bonding: a randomized controlled clinical trial

This study assessed the in vivo bond failure of the single component orthodontic self-etching primer system, Ideal 1 (GAC Orthodontic Products) and compared it with the conventional acid etching using a conventional 37% o-phosphoric acid, rinsing and drying regimen when bonding stainless steel orthodontic brackets to enamel. Prospective randomized, controlled clinical trial. Orthodontic Department, Bristol Dental School. Twenty consecutive patients undergoing upper and lower fixed orthodontic treatment entered this cross-mouth control study. Diagonally opposite quadrants were randomly allocated to either the self-etching primer group or the conventional etching group. A total of 339 teeth were bonded with Ideal 1 light-cured adhesive. Bond failures and locus of bond failure were then recorded at 1, 6 and 12 months. Significantly more bond failures occurred at each of the 3 time intervals, 1, 6 and 12 months, where the enamel was pretreated with the Ideal I self-etching primer, than when the enamel was treated with the conventional etchant, 37% o-phosphoric acid. With the latter the cumulative bond failure rates were 3.0, 5.3 and 14.8%, respectively. With the self-etching primer the cumulative failure rates were 29.4, 56.5 and 72.4%. The study found that enamel pre-treatment with the Ideal 1 self-etching primer system prior to orthodontic bonding results in an unacceptably high bond failure rate when compared with conventional enamel acid etching.

Retrospective Study of Five-year Clinical Performance of Direct Composite Restorations Using a Self-etching Primer Adhesive System

This study was conducted to assess the five-year clinical performance of composite restorations using a self-etching primer adhesive system, Clearfil Liner Bond II. Restorations were rated using the following scale: A--Good; B--Clinically acceptable; C--Clinically unacceptable; or D--Already replaced. The ratings were analyzed using Freedman's test (p=0.01) and Steel-Dwass test (p=0.05). A total of 83 restorations from 36 patients were identified from treatment records. Twenty-six restorations (31.3%) presented A rating and 36 restorations (43.4%) were clinically acceptable (B rating), while five (6.0%) received C rating and 16 (19.3%) had already been replaced (D rating). The mean survival rate of serviceable restorations (i.e., combined A and B ratings) after five years was 74.7%. It was found that cavity form, including cavity size, and occlusal contact seemed to influence longevity.

Microleakage of three self-etching primer adhesive systems

Microleakage of three self-etching primer adhesive systems

Micro-shear bond strength and morphological analysis of a self-etching primer adhesive system to fluorosed enamel

The aim of this study was to evaluate micro-shear bond strength and morphological analysis of a self-etching primer adhesive system to fluorosed enamel. Extracted human molars were classified according to the severity of fluorosis using Thylstrup and Fejerskov index into four groups (TFI: 0, normal; 1-3, mild fluorosis; 3-6, moderate fluorosis; 6-7, severe fluorosis) and divided into following two sub-groups. For the first sub-group, a self-etching primer adhesive system was applied to the ground enamel surfaces and the other sub-group was conditioned with 37% phosphoric acid for 30s prior to application of the same adhesive system. Teeth were then restored with a resin composite, stored for 24h in water and micro-shear bond strengths were measured. After shear testing, the fracture modes were observed under a laser scanning microscope. Morphological study of etching patterns and adhesive interface was done under a scanning electron microscope (SEM). The data were analyzed using two-way ANOVA and Sheffe test (p=0.05). No statistically significant difference was there between the different degrees of fluorosis in each sub-group. However, significant difference in the bond strengths between phosphoric acid etching and self-etching was found in moderate and severe groups. The SEM observations showed at the resin-enamel interface, thick resin tag like extensions penetrated around 3.5 microm into the enamel etched with phosphoric acid, while self-etching primer created, 1 microm lamina like penetration. Severity of fluorosis affects the micro-shear bond strength of a self-etching bonding system to fluorosed enamel.

Shortening of primary dentin etching time and its implication on bond strength

The aim of this study was to investigate the influence of shortening the etching time on the bond strength of a conventional and a self-etching primer adhesive system used in primary tooth dentin. Flat dentin surfaces were obtained from 24 primary molars, randomly assigned to 4 experimental groups. The adhesive systems Single Bond and Clearfil SE Bond were applied in two groups according to the manufacturers' recommendations. In the other two groups, the adhesives were applied after half-time of acid etching, 7 s for Single Bond and 10 s for Clearfil SE Primer. Resin crowns were built up and after 24 h storage in water at 37 degrees C, the teeth were sectioned to produce beams with cross-sectional area of approximately 0.49 mm2. Specimens were tested in tension at 0.5 mm/min until failure. Fractured specimens were analyzed to determine the failure mode. Tensile bond strengths for Single Bond in primary dentin were higher than for Clearfil SE Bond. Shortening of acid etching time improved bond strength only for Single Bond, while no statistically significant difference was observed for Clearfil SE Bond when both etching times were compared. No detrimental effect on bond strength was observed when the time of acid etching was shortened in 50%. Shortening the time for a procedure in a small child without compromising the quality of the work is a very important finding for the practicing pediatric dentist.

The effect of thermal cycling on the bovine dentine shear bond strength of current adhesive systems.

The aim of this study was to evaluate the effect of thermal cycling on shear bond strength to bovine dentine of four current adhesive systems. Forty bovine incisors were ground flat with #600-grit silicon carbide paper to obtain superficial coronal dentine surfaces. Three one-bottle (etch and rinse) adhesive systems (Single Bond, Bond 1, One Step), and one self-etching primer adhesive system (Clearfil Liner Bond 2V) were evaluated. Dentine was conditioned and bonded with the adhesive systems tested according to the manufacturers' instructions. A cylindrical teflon mould (3 x 4 mm) was placed over the bonded area (to eliminate the bonded surface) and filled with composite resin. For each adhesive system the filling composite used was from the same manufacturer. Ten specimens were prepared for each material and all specimens were conditioned at 37 degrees C for 24 h. Five specimens of each material (half of the specimens) were thermocycled at 5000 cycles (at 5, 37, 55 and 37 degrees C) with a dwell time of 15 s and bonds were stressed in shear at a rate of 0.5 mm min(-1) until failure. Data were analysed by one-way anova and Student-Newman-Keuls rank test (alpha=0.05). Statistical analysis revealed that thermal cycling significantly (P < 0.05) reduced the bond strengths of all adhesive systems. Bond strengths prior to thermocycling were not significantly different (P > 0.05), except for One Step which revealed the lowest bond strength, and varied from 22.5 +/- 3.34 to 10.98 +/-0.87 MPa. After thermal cycling, the bond strengths ranged from 9.35 +/- 1.13 to 6.06 +/- 1.77 MPa. Failures after testing and prior to thermal cycle were most commonly adhesive failures between the bonding resin and dentine associated with partial cohesive failures in the adhesive resin (type 2). Adhesive failures between bonding resin and dentin (type 1) after thermocycling were most commonly seen.

Effect of dentin conditioners on the microtensile bond strength of a conventional and a self-etching primer adhesive system

Objective: To investigate the effect of different dentin treatments on the microtensile bond strength of a self-etching primer and a simplified, total-etch adhesive system. Methods: Flat dentin surfaces were created on extracted human third molars. The surfaces were treated with one of the following conditioners: self-etching primer for 20 s (Clearfil SE Primer), 37% phosphoric acid for 15 s or 0.5 M EDTA for 30 s. Conditioned surfaces were then bonded with either Clearfil SE Bond or Single Bond followed by resin composite (Z250) build-ups constructed incrementally. Application of SE Primer was included when Clearfil SE Bond was used, after phosphoric acid and EDTA conditioning. After 24 h storage in water at 37 °C, the teeth were longitudinally sectioned across the bonded interface to produce beams with 1.0 mm 2 of adhesive area, tested with the microtensile method at a rate of 0.5 mm/min. Data were analyzed using two-way ANOVA and Tukey's test. Results: The highest bond strength mean was found for the combination SE Primer/Single Bond (58.5±20.8 MPa), followed by the EDTA/Clearfil SE Bond (47.8±15.1 MPa) and phosphoric acid/Single Bond (40.9±14.3 MPa). The remaining combinations showed statistically similar ( p>0.05) tensile bond strength. Significance: The bond performance of the adhesives tested was dependent on the dentin conditioner. Pre-treatment with a mild etchant such as 0.5 M EDTA improved the bond strength of Clearfil SE Bond. Single Bond performed better when a self-etching primer was used as the dentin conditioner, probably by preventing the formation of a defective zone at the base of the hybrid layer. Overall results indicate that higher bond strengths can be achieved by conditioning dentin with milder etchants, suggesting that deeper demineralization may prevent proper resin infiltration, hence compromising the bond.

The effect of light-curing modes on the microleakage of cervical resin composite restorations.

This study investigated the effect of light-curing modes on the microleakage of cervical resin composite restorations. Eighty wedge-shaped cervical cavities, C-factor approximately 1.3, were prepared on the labial surface of bovine incisors. The cavities were treated with a two-step experimental self-etching primer adhesive system containing an antibacterial monomer (ABF), according to the manufacturer's instructions, and filled with a single increment of a hybrid resin composite. The restorations were allocated randomly into four groups of 20: Group 1-the restorations were light-cured for 40 s with a conventional light-curing unit (New Light VL-II); Group 2-the restorations were cured with Candelux using a two-step mode; Group 3-the restorations were cured with Astralis 7 using a ramping mode; Group 4-the restorations were light-cured for 3 s with a plasma arc light-curing unit (Wave Light). Half of the specimens from each group were subjected to thermocycling (5-60 degrees C, 15 s dwell time, 5000 cycles) prior to immersion in 0.5% basic fuchsin. The teeth were sectioned and the degrees of dye penetration were scored. The data were analyzed with either the Kruskal-Wallis test or the Mann-Whitney U-test (p < 0.05) No significant differences were found in the microleakage scores among the light-curing modes used. The restorations tended to display more microleakage when they were subjected to thermocycling, but the differences were not statistically significant. These findings suggest that light-curing modes may have no effect on the microleakage of cervical cavities with a small C-factor, as is the case in this study.

Influence of appication time of self-etching primers on dentinal microtensile bond strength

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (μ TBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. μ TBS was tested and statistically compared using by one-way ANOVA and Tukey’ s Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased μ TBS to dentin. [J Kor Acad Cons Dent 29(5):430-438, 2004]

Bond strength and microleakage for self-etching primer adhesive systems

Bond strength and microleakage for self-etching primer adhesive systems

INFLUENCE OF SELF‐ETCHING PRIMER DRYING TIME ON ENAMEL BOND STRENGTH OF RESIN COMPOSITES

ABSTRACT Objective: The purpose of this study was to evaluate the effects of self‐etching primer drying times on the bond strength of resin to bovine enamel. Materials and Methods: Three self‐etching primer adhesive systems–Imperva Fluoro Bond® (Shofu Inc., Kyoto, Japan), Clearfil® Liner Bond (Kuraray Co. Ltd., Osaka, Japan), and Mac Bond® II (Tokuyama Corp., Tokyo, Japan)– were used in this study, The labial enamel surfaces of bovine incisors were exposed by grinding with 240‐grit and 600‐grit wet silicon carbide paper. The primers were applied to enamel surfaces as per manufacturers' instructions. After priming, the surfaces were dried with compressed air for 0, 2, 5, 10, 20, or 30 seconds from 10 cm above the surface using a three‐way syringe. Following the application of adhesive resin, resin composites were applied into molds (diameter = 4 mm, depth = 2 mm) and were light‐cured. The shear test was performed at a crosshead speed of 1.0 mm/min. The ultrastructure of resin‐enamel interfaces was observed with SEM at magnifications of 2,000× to 3,500×. Results: Mean enamel bond strengths varied with the different drying times and ranged from 8.2 to 17.4 MPa for Clearfil Liner Bond, from 10.9 to 16.3 MPa for Imperva Fluoro Bond, and from 17.5 to 19.4 MPa for Mac Bond. For Clearfil Liner Bond and Imperva Fluoro Bond, mean bond strengths increased significantly at the 10‐second drying time, whereas Mac Bond did not experience a significant change in bond strengths. SEM examination revealed morphologic differences among the groups with varying drying times. Resin tag penetration was not clearly seen at the 0‐second drying time, but resin tags appeared to be intimately adapted to the enamel surface in specimens at the 30‐second drying time. Conclusions: The drying time of the self‐etching primer prior to the application of bonding resin affected the shear bond strength of resin to enamel for two self‐etch adhesive systems.

Shear bond strength of orthodontic brackets bonded with a modified 1-step etchant-and-primer technique

When bonding orthodontic brackets to enamel, most orthodontists use a conventional technique of etching tooth enamel with phosphoric acid, placing a hydrophilic primer on the etched, rinsed, and dried surface, then bonding the bracket with an adhesive resin composite. New systems simultaneously etch and prime the tooth surface in preparation for bonding. The purpose of this study was to compare the shear bond strength of orthodontic brackets bonded to enamel with a conventional, multistep adhesive system and a self-etching primer adhesive system. In addition, a third group was included in which the air dispersion step in the self-etching primer system was omitted. Brackets were bonded to 108 extracted human molars according to 1 of 3 experimental protocols—group 1: conventional multistep adhesive (n = 36); group 2: self-etching primer system (n = 36); group 3: self-etching primer system without air dispersion (n = 36). Specimens were loaded to failure in a universal testing machine (Instron, Canton, Mass). Mean shear bond strengths in megapascals (standard deviation) were 11.3 (2.2), 11.9 (3.2), and 8.2 (2.8) for groups 1, 2, and 3, respectively. Data were subjected to 1-way analysis of variance at α = .05. The mean shear bond strength of the self-etching primer group in which the air dispersion step was omitted was significantly less than in the other 2 groups ( P < .001). However, there was no difference in mean shear bond strength between the conventional, multistep adhesive system and the self-etching primer system when the primer was dispersed correctly ( P = .34).

Adhesive Sealing of the Pulp Chamber

The purpose of this in vitro study was to evaluate quantitatively the ability of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar teeth were used. The top of pulp chambers and distal halves of the roots were removed using an Isomet saw. The canal orifices were temporarily sealed with a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a wet bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydride adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of the seal of each specimen was measured by fluid filtration immediately and after 1 day, 1 wk, and 1 month. Even after 1 month the resins showed an excellent seal. Zinc oxide-eugenol had significantly more leakage when compared with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.

Ondontecrexis—the effects of rapid decomposition on restored teeth

Several self-adhesive luting agents have recently been introduced on the market. It is crucial to know the effectiveness of such luting agents prior to their clinical application.The purpose of this study was to evaluate the microtensile bond strengths (μTBS) produced by different self-adhesive cements and compare them with conventional luting agents.Six self-adhesive cements (RelyX Unicem (UN), RelyX U100 (UC), SmartCem 2 (SC), G-Cem (GC), Maxcem (MC), and SeT (SET), and 2 conventional luting agents, one that uses a 2-step etch-and-rinse adhesive (RelyX ARC (RX)), and one that uses a 1-step self-etching adhesive (Panavia F (PF)), were used in this study. An additional group included the use of a 2-step self-etching primer adhesive system (Clearfil SE Bond) prior to the application of Panavia F (PS). Fifty-four human molars were abraded to expose occlusal surfaces and were assigned to 9 groups according to the luting material (n=6). Five composite resin (Filtek Z250) discs (12 mm in diameter, 5 mm thick) were cemented on the teeth according to manufacturers' instructions. After 24 hours of water storage, restored teeth were serially sectioned into beams with a cross-sectional area of approximately 1 mm2 at the bonded interface and were tested in tension with a crosshead speed of 1 mm/min. Failure mode was determined using scanning electron microscopy. Data were statistically analyzed by 1-way ANOVA and Tukey's studentized range HSD test (α =.05).Mean bond strengths (SD) in MPa were: RX, 69.6 (16.6)A; PS, 49.2 (9.7)A; PF, 33.7 (13.9)AB; GC, 16.9 (10.3)BC; UC, 15.3 (3.4)BC; UN, 12.5 (2.4)C; MC 11.5 (6.8)CD; SC, 8.5 (4.9)CD; SET, 4.6 (0.5)D. Groups with different uppercase letters were significantly different from each other (P<.05). The predominant failure mode of the self-adhesive cements was adhesive between the resin cement and dentin.The bond strengths produced by the multistep luting agents were significantly higher than those observed for most self-adhesive cements. (J Prosthet Dent 2009;102:306-312)