3种自酸蚀粘结剂粘结托槽的剪切强度比较

目的:比较3种自酸蚀粘结剂粘结正畸托槽时的剪切粘结强度。方法:将36颗人前磨牙随机均分为3组,分别用3种自酸蚀粘结剂:改良一步法自酸蚀粘结系统Adper Prompt L-Pop Self Etch Adhesive(组1)、释氟抗菌型自酸蚀粘结系统Clearfil Protect Bond(组2)、释氟型自酸蚀粘结系统Transbond Plus Self Etching Primer(组3)粘结金属托槽,用万能应力测试机测试其剪切粘结强度,在体式显微镜下评价各组牙齿表面的剩余粘结剂指数,并进行统计学分析。结果:单因素方差分析显示各组间的剪切粘结强度有显著性差异(P<0.05),组2的剪切粘结强度最高,组1和组3间的剪切粘结强度差异无统计学意义。Kruskal-Wallis检验表明各组的剩余粘结剂指数无差别(P>0.05)。结论:3种自酸蚀粘结剂粘结托槽的剪切粘结强度存在一定的差异,但均能满足正畸临床治疗的需求。     

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 S3 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 S3 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 S3 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 S3 Bond. Marginal adaptation was significantly better for Clearfil S3 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.     

Microtensile bond strength of current dentin adhesives measured immediately and 24 hours after application

PURPOSE: To evaluate the immediate microtensile bond strengths achieved with representative adhesive systems from each of the four current bonding approaches. MATERIALS AND METHODS: Resin composite was bonded incrementally to flat, midcoronal dentin from 33 human molars, using the adhesives (Adper Scotchbond MP; Adper Scotchbond 1; Optibond Solo Plus; Clearfil SE Bond; AdheSE; Tyrian SPE + One Step Plus; Optibond Solo Plus self-etching; One-Up Bond F; iBond; Adper Prompt L-Pop; Xeno III) according to the respective manufacturer's instructions. The bonded specimens were immediately sectioned into sticks and underwent microtensile bond testing either immediately or after 24 h. Data were analyzed with two-way ANOVA and LSD tests. RESULTS: No significant differences were found between immediate and 24-h bond strengths (p > 0.05). However, significant differences were observed among adhesives (p = 0.001). The all-in-one adhesive iBond showed statistically lower values when compared to all the other adhesives. Adper Prompt L-Pop, Xeno III, Tyrian SPE + One Step Plus and One-Up Bond F, all self-etching adhesives, were significantly weaker than AdheSE, Optibond Solo Plus, Adper Scotchbond 1, Optibond Solo Plus self-etching, Clearfil SE Bond, and Adper Scotchbond MP, which did not differ statistically from each other. CONCLUSION: Microtensile bond strengths of representative adhesive systems from the four categories of bonding agents were not equivalent, with the lowest values recorded for the one-step self-etching adhesives. There were no differences in the bond strengths when measured immediately and after 24 h.     

An ex vivo investigation into the bond strength of orthodontic brackets and adhesive systems.

The aim of this study was to compare the shear bond strength of Adhesive Precoated Brackets (APC) with that of two types of uncoated bracket bases, Straight-Wire and Dyna-Lock. Two types of orthodontic adhesives were used, Transbond XT and Right-On. Three different curing times were evaluated with the APC brackets in order to find the best. Adhesive remnants on the enamel surface following debond were evaluated using the Adhesive Remnant Index (Artun and Bergland, 1984). Bond strengths ranged from 11.00 to 22.08 MPa. For both types of brackets Transbond produced a significant increase in bond strength compared to Right-On. The Dyna-Lock/Right-On combination produced the poorest results. APC brackets cured for 40 s had similar bond strengths to uncoated brackets fixed by means of Transbond. Overall, 79 per cent of specimens had less than half the tooth surface covered with adhesive following debond. Significantly more adhesive remained on tooth surfaces following debond of the Straight-Wire/Right-On group than any other bracket/adhesive combination. Bond strengths were higher with light-cured Transbond than with chemically-cured Right-On. When Transbond is used in association with APC brackets a 40-second cure time is recommended.     

Effects of self-etching primer on shear bond strength of orthodontic brackets at different debond times

OBJECTIVE: To evaluate the effect of a self-etching primer on shear bond strengths (SBS) at the different debond times of 5, 15, 30, and 60 minutes and 24 hours. MATERIALS AND METHODS: Brackets were bonded to human premolars with different etching protocols. In the control group (conventional method [CM]) teeth were etched with 37% phosphoric acid. In the study group, a self-etching primer (SEP; Transbond Plus Self Etching Primer; 3M Unitek, Monrovia, Calif) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT; 3M Unitek) and light-cured for 20 seconds in both groups. The shear bond test was performed at the different debond times of 5, 15, 30 and 60 minutes and 24 hours. RESULTS: Lowest SBS was attained with a debond time of 5 minutes for the CM group (9.51 MPa) and the SEP group (8.97 MPa). Highest SBS was obtained with a debond time of 24 hours for the CM group (16.82 MPa) and the SEP group (19.11 MPa). Statistically significant differences between the two groups were not observed for debond times of 5, 15, 30, or 60 minutes. However, the SBS values obtained at 24 hours were significantly different (P < .001). CONCLUSIONS: Adequate SBS was obtained with self-etching primer during the first 60 minutes (5, 15, 30 and 60 minutes) when compared with the conventional method. It is reliable to load the bracket 5 minutes after bonding using self-etching primer (Transbond Plus) with the light-cure adhesive (Transbond XT).     

Shear bond strength of orthodontic brackets bonded with self-etching primers

PURPOSE: To evaluate the effectiveness of two self-etching primers for bonding brackets in comparison with the conventional acid-etch technique. METHODS: The brackets were bonded to extracted human premolars using the resin orthodontic adhesive system, Transbond XT. This procedure was carried out in accordance with one of the following three protocols of enamel conditioning: (1) 37% phosphoric acid etching, (2) Transbond Plus Self Etching Primer (TSEP), and (3) Adper Prompt L-Pop (Adper PLP). Shear bond strength was measured with a universal test machine. The adhesive remnant on the tooth after debonding was quantified using image analysis equipment. Scanning electron microscopy (SEM) was used to observe the effects of conditioning of each product on the enamel. RESULTS: No significant differences were observed in bond strengths of the three groups evaluated (P> 0.05). Self-etching primers left significantly less adhesive on the tooth than the conventional acid-etch technique and, among them, Adper PLP left significantly less adhesive than TSEP (P< 0.017). SEM observations showed that the etching effect of self-etching primers approximated to the etching effect of phosphoric acid.     

Effect of self-etching primers on bond strength--are they reliable?

Currently introduced self-etching primers combine conditioning and priming agents into a single product. The purpose of this study was to determine the effects of using three self-etching primers on the shear bond strength (SBS) of orthodontic brackets and on the bracket/adhesive failure mode. Brackets were bonded to extracted human teeth according to one of four protocols. In the control group, teeth were etched with 37% phosphoric acid. In the experimental groups, the enamel was conditioned with three different self-etching primers, Clearfil SE Bond (CSE), Etch & Prime 3.0 (EP3), or Transbond Plus (TBP), as suggested by the manufacturer. The brackets were then bonded with Transbond XT in all groups. The present in vitro findings indicate that conditioning with TBP before bonding orthodontic brackets to the enamel surface resulted in a significantly (P < or = .001) higher SBS (mean, 16.0 +/- 4.5 MPa) than that found in CSE, EP3, and the control (acid-etched [AE]) groups. CSE produced bond strength values (mean 11.5 +/- 3.3 MPa) that are statistically comparable to those produced by acid etching (mean 13.1 +/- 3.1 MPa). The use of EP3 for enamel conditioning resulted in the lowest mean SBS value (mean 9.9 +/- 4.0 MPa). A comparison of the adhesive remnant index scores indicated that there was more residual adhesive remaining on the teeth that were treated with conventional acid etching than in the CSE and EP3 groups. In the TBP group, the failure sites were similar to those of the AE group but different from those of the CSE group.     

Bond strengths and adhesive remnant index of self-etching adhesives used to bond brackets to instrumented and uninstrumented enamel

PURPOSE: This study evaluated bond strengths of orthodontic brackets to instrumented and uninstrumented enamel using self-etching adhesive systems when compared to a total-etch adhesive system. The adhesive remnant index (ARI) was also determined after debonding. METHODS: 140 bovine incisors were included in acrylic resin, and divided randomly in two groups: instrumented vs. uninstrumented enamel. For the instrumented enamel, specimens had their facial enamel ground flat to 600-grit. In each group, specimens were subdivided into four experimental subgroups according to the adhesive technique used: Transbond Plus, Adper Prompt L-Pop, iBond, and Adper Single Bond, applied following manufacturers' instructions. Orthodontic brackets were bonded to the treated instrumented or uninstrumented enamel with Transbond XT light-cured resin-based composite cement, and the bond strength was tested in shear mode after 7 days. One group where no etch and no adhesive were used served as a control. ARI scores were determined after debonding. RESULTS: There was no statistically significant difference in mean bond strengths between instrumented and uninstrumented enamel for any of the adhesive systems (P > or = 0.05). No significant differences were observed for bond strengths among the adhesives tested (P = 0.308), and all experimental groups resulted in mean bond strengths significantly higher than the controls (P < 0.05). Statistically significant differences were identified when ARI scores were compared, with less adhesive remnants being observed for iBond (uninstrumented enamel) and the control groups (P < 0.05).     

Microleakage beneath ceramic and metal brackets bonded with a conventional and an antibacterial adhesive system

OBJECTIVE: To assess microleakage of a tooth-adhesive-bracket complex when metal or ceramic brackets were bonded with a conventional and an antibacterial self-etching adhesive. MATERIALS AND METHODS: Forty freshly extracted human premolars were randomly assigned to four equal groups and received the following treatments: group 1 = Transbond XT + metal bracket, group 2 = Transbond XT + ceramic bracket, group 3 = Clearfil Protect Bond + ceramic bracket, and group 4 = Clearfil Protect Bond + metal bracket. After photopolymerization, the teeth were kept in distilled water for 1 month and thereafter subjected to thermal cycling (500 cycles). Specimens were further sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned and examined under a stereomicroscope, and scored for marginal microleakage for the adhesive-tooth and bracket-adhesive interfaces from incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis test and Mann-Whitney U-test with Bonferroni correction. RESULTS: All groups demonstrated microleakage between the adhesive-enamel and bracket-adhesive interfaces. A significant difference was observed among all groups (P < .05) for the microleakage between the bracket-adhesive interface. Metal brackets exhibited significantly more microleakage than did ceramic brackets between the bracket-adhesive interface with either of the adhesives. Clearfil Protect Bond exhibited results similar to Transbond XT. Clearfil Protect Bond may be a choice of adhesive in bracket bonding because of its antibacterial activity and similar microleakage results with the orthodontic adhesive. CONCLUSIONS: Metal brackets cause more leakage between an adhesive-bracket interface, which may lead to lower clinical shear bond strength and white-spot lesions.     

A New Generation of Self-etching Adhesives: Comparison with Traditional Acid Etch Technique

OBJECTIVE: The aim of this study was to determine the shear bond strength (SBS), etching pattern and depth, and debonding performance of several market-leading, self-etching (SE) adhesives primarily used in restorative dentistry (iBond, Clearfil S(3) Bond, Clearfil Protect Bond, AdheSE, XenoIII), two experimental self-etching adhesives (exp. Bond 1, exp. Bond 2) and one experimental self-etching cement (SE Zement) used with and without prior phosphoric acid-etching, and to compare them to an orthodontic self-etching product (Transbond Plus SE Primer) and to traditional acid-etch technique (Transbond XT Primer, phosphoric acid) MATERIALS AND METHODS: All adhesives were applied on pumiced and embedded bovine incisors following the manufacturers' instructions. Then one bracket each (coated with Transbond XT composite) was bonded (n = 20). Transbond XT was polymerized for 20 s from the incisal and gingival sides using a halogen device positioned at a constant 5 mm from and a 45 degrees angle to the specimen. The specimens were stored in distilled water for 24 h at 37 degrees C before measuring SBS. The ARI (adhesive remnant index) for all specimens was determined from the sheared-off brackets of each. After conditioning, the surface texture was morphologically evaluated from scanning electron microscope (SEM) images, while the etching depth was determined using a confocal laser-scanning microscope (CLSM). All groups were tested for normal distribution and analyzed by applying ANOVA, Kruskal-Wallis or the t test. In addition, a Bonferroni correction was used. RESULTS: The median values of the SBS tests were: SE Zement 3.0 MPa, SE Zement preceded by phosphoric acid etching 11.2 MPa, experimental bond 1: 7.4 MPa, experimental bond 2: 5.6 MPa, iBond 8.1 MPa, Clearfil S(3) Bond 14.1 MPa, Clearfil Protect Bond 16.6 MPa, Clearfil SE Bond 15.9 MPa, AdheSE 16.0 MPa, XenoIII 16.1 MPa, Transbond SE Primer 20.7 MPa, acid-etching+Transbond XT Primer 21.0 MPa. With the exception of iBond, we observed no significant differences among the self-etching adhesives used in Restorative Dentistry or in comparison to the Transbond Plus SE Primer. No significant differences were apparent even when compared to the Transbond XT Primer after phosphoric acid-etching. Both experimental bonding agents and SE Zement without acid etching performed significantly worse than the products mentioned above, failing to demonstrate sufficient adhesive strength. SEM examination revealed less distinctive enamel-etching patterns for self-etching products than for phosphoric acid-etching. CLSM analysis revealed etching depths between 0.5 and 20 microm depending on the product. When self-etching products were used, less residual composite remained on the enamel surface than after phosphoric acid-etching. CONCLUSIONS: All the adhesives tested are suitable for bonding orthodontic brackets and to reduce the risk of enamel fracture while minimizing etching depth, which in turns means less conditioning-related enamel loss. More development is needed to improve the etching performance of both experimental bonding agents and SE Zement.     

Comparison of shear bond strengths of orthodontic brackets bonded with flowable composites

This study evaluated the shear bond strengths of orthodontic brackets bonded to human premolars using five different combinations of flowable composites and one-step self-etching adhesives (n=12): (1) Adper Easy Bond+Filtek Supreme XT Flow; (2) Futurabond NR+Grandio Flow; (3) Clearfil S3 Bond+Clearfil Majesty Flow; (4) AdheSE One+Tetric EvoFlow; and (5) Transbond Plus Self Etching Primer+Transbond XT Light Cure Adhesive. After shear bond strength testing, adhesive remnant index (ARI) scores were given according to the amount of adhesive and resin remaining on the brackets. On shear bond strength, there were no statistically significant differences between Groups 2 and 4 and between Groups 3 and 5 (p>0.05). On ARI scores, the predominant ARI scores in Groups 1, 2, 3, and 5 were 4, 2, 5, and 4 respectively; in Group 4, they were 0 and 4. Results showed that some combinations of flowable composites and self-etching adhesives might not be suitable for orthodontic use due to their low shear bond strengths and high ARI scores -with the latter signaling the risk of damaging the enamel surface during debonding.     

Influence of Modifying the Resin Coat Application Protocol on Bond Strength and Microleakage of Metal Orthodontic Brackets

Objective:To determine the shear bond strength (SBS) and microleakage of metal brackets bonded with two different adhesives when a resin coat and the adhesive were light-cured separately or simultaneously.Materials and Methods:Eighty stainless steel brackets were bonded to the enamel of extracted premolars, 40 with Transbond Plus adhesive (group 1) and 40 with Transbond XT (group 2). Each group was subdivided into four equal subgroups; a, b, c, and d. Brackets in subgroups a and b were bonded with the adhesive without coating. For brackets in subgroup c, Ortho-Choice Ortho-Coat was applied and cured after curing of the adhesive, while the coat was applied and cured with the adhesive for brackets in subgroup d. The specimens were immersed in a 2% methylene blue dye. After debonding, the teeth and brackets were examined with a stereomicroscope. The data were subjected to a two-way analysis of variance (ANOVA), Duncan multiple range test, and Pearson correlation.Results:Both adhesives had comparable SBS. Curing of the coat after curing of the adhesive showed significantly higher SBS than other protocols. There was no significant difference in SBS of the adhesives without coating and with curing of the coat and adhesive simultaneously. Application of the coat significantly reduced microleakage. There was a significant negative relationship between SBS and microleakage.Conclusions:SBS was significantly improved with curing of the coat and adhesive separately, while it was not adversely affected when the coat and adhesive were cured simultaneously. Using the coat with either protocol significantly reduced the microleakage.     

Effect of applying a sustained force during bonding orthodontic brackets on the adhesive layer and on shear bond strength

The objective of this research was to investigate the effect of applying a sustained seating force during bonding on the adhesive layer and on shear bond strength (SBS) of orthodontic brackets. Forty human premolars divided into two groups were included in the study. Stainless steel brackets were bonded to the premolars with Transbond XT light cure adhesive and Transbond Plus Self Etch Primer (SEP). The brackets in both groups were subjected to an initial seating force of 300 g for 3 seconds, sufficient to position the bracket. The seating force was maintained throughout the 40 seconds of light curing in group 2. SBS was tested 24 hours after bracket bonding with a shear blade using an Instron testing unit at a crosshead speed of 2 mm/minute. A Student's t-test was used to compare the bond strength of the two groups and a chi-square test to compare the frequencies of the adhesive remnant index (ARI) scores. The mean SBS was significantly different between the two groups (P=0.025). The bond strength was higher (mean 8.15±0.89 MPa) in group 2 compared with group 1 (mean 7.39±1.14 MPa). There was no significant difference (P=0.440) in the ARI scores between the two groups. Applying a sustained seating force during orthodontic bracket bonding improves bond strength but does not change the distribution of the ARI scores.     

Bracket bond strength comparison between new unfilled experimental self-etching primer adhesive and conventional filled adhesives

Objective:To determine if a new unfilled experimental self-etching primer (SEP) adhesive system (SBP-40TX + C&B Metabond) that incorporates a methyl methacrylate–based 4-META/TBB (4-methacryloxyethyl trimellitate anhydride tri-n-butyl borane) resin can provide adequate shear bond strength (SBS) when used for bonding orthodontic brackets.Methods and Materials:Forty-eight human maxillary premolars were randomly divided into three groups of 16 specimens each. Brackets were bonded with three bonding systems. A filled Bis-GMA/TEGDM (triethylene glycol dimethacrylate)–based SEP adhesive system (Transbond Plus) and an unfilled conventional etch-and-rinse adhesive system (C&B Metabond) were used for comparison. The SBS for each sample was examined with a universal testing machine, and the Adhesive Remnant Index score was calculated. Enamel surfaces after conditioning were examined using a scanning electron microscope. Data were compared by one-way analysis of variance and a χ² test.Results:The experimental SEP showed a milder etching pattern than Transbond Plus SEP. No statistically significant differences in the mean SBS were found between the specimens bonded with the unfilled experimental SEP adhesive system (10.0 MPa) and the filled SEP adhesive system (8.7 MPa). The unfilled experimental SEP adhesive system showed less residual adhesive than the filled SEP adhesive system.Conclusions:The unfilled experimental SEP adhesive system showed a clinically sufficient SBS that was equivalent to the filled SEP adhesive system.     

Effect of self-etching primer and adhesive formulations on the shear bond strength of orthodontic brackets.

PURPOSE: Despite many published articles on the bond strength of self-etching primers and adhesives in the restorative dentistry literature, there have been relatively few laboratory studies of the bond strength of new orthodontic materials, and, in most of these published studies, investigators used various methodologic approaches during different stages of the in vitro testing procedures. The aim of this study was to compare the shear bond strength of 4 self-etching primer and adhesive formulations, a nonrinse conditioner and acetone adhesive system, and a conventional system. MATERIAL: The self-etching products tested were Prompt L-Pop (3M ESPE, Seefeld, Germany), Clearfil SE Bond (Kuraray Dental, Osaka, Japan), FL Bond (Shofu Dental, Kyoto, Japan), and One-Up Bond F (Tokuyama, Tokyo, Japan); the nonrinse conditioner and acetone-based adhesive system was NRC and Prime&Bond NT (Dentsply International, Konstanz, Germany); the conventional acid-etch and bond system was Transbond XT (3M Unitek, Monrovia, Calif). Brackets were bonded to intact bovine mandibular incisors (n = 7 per group) according to each manufacturer's recommendations. The specimens were first stored in deionized water at 37 degrees C for 24 hours and then subjected to thermal cycling in deionized water at 5 degrees C +/- 2 degrees C to 55 degrees C +/- 2 degrees C for 1000 cycles. To facilitate degradation of bonds, the specimens were further stored in distilled water for 6 weeks before debonding procedures. RESULTS: The shear bond strengths of the 5 experimental groups were all significantly lower (P < .05) than that of the control group (Prompt L-Pop, 1.72 +/- 0.13 MPa; Clearfil SE Bond, 1.75 +/- 0.19 MPa; FL Bond, 1.71 +/- 0.22 MPa; One-Up Bond F, 1.77 +/- 0.14 MPa; control, 10.5 +/- 0.86 MPa) but not different from one another (P > .05). CONCLUSIONS: The tested self-etching primer and adhesive systems produced bond strength values much lower than that of the control product. Clinically, these products might not be suitable for orthodontic bracket bonding in terms of the shear bond strength achieved after thermal cycling and water storage.     

Dentin bonding on different walls of a class II preparation

PURPOSE: To evaluate the bond strength on different cavity walls of Class II preparations. Different bonding systems and the effect of thermomechanical cycling were investigated. MATERIALS AND METHODS: Human third molars received MOD preparations with dentin margins. Teeth were randomly assigned to 18 groups (n=5) according to the combination of cavity wall (axial, occlusal, and gingival), bonding system (Single Bond Plus, Clearfil SE Bond, and Adper Prompt) and the occurrence of thermomechanical cycling. Restorations were concluded with Filtek Z250 composite. Specimens were sectioned according to the respective cavity wall (4 slabs/restoration), and the adhesive interface was trimmed to an hourglass shape (1 mm2). Slabs were tested under tension, and failure mode was observed. Bond strength data were analyzed with three-way ANOVA/Tukey's test. RESULTS: Single Bond Plus and Clearfil SE Bond performed similarly under most experimental conditions. Single Bond Plus presented similar bond strength on the three cavity walls, regardless of the aging condition. Clearfil SE Bond exhibited significant differences among cavity walls: the occlusal wall showed higher means in both aging conditions. Non-aged gingival walls and aged axial and gingival walls yielded lower means. Non-aged Adper Prompt produced similar bond strengths on the three cavity walls. After thermomechanical cycling, the gingival wall showed lower means. CONCLUSION: The effect of cavity walls was dependent on the bonding system and thermomechanical cycling. Adper Prompt demonstrated bond strengths lower than Single Bond Plus or Clearfil SE Bond under most experimental conditions.     

Microtensile bond strength of contemporary adhesives to primary enamel and dentin

The purpose of this study was to assess bond strength of three self-etching and two total-etch adhesive systems bonded to primary tooth enamel and dentin. MATERIALS AND METHODS: Forty extracted primary human molars were selected and abraded in order to create flat buccal enamel and occlusal dentin surfaces. Teeth were assigned to one of the adhesive systems: Adper Scotch Bond Multi Purpose, Adper Single Bond 2, Adper Prompt L-Pop, Clearfil SE Bond and AdheSE. Immediately to adhesive application, a composite resin (Filtek Z250) block was built up. After 3 months of water storage, each sample was sequentially sectioned in order to obtain sticks with a square cross-sectional area of about 0.72 mm2. The specimens were fixed lengthways to a microtensile device and tested using a universal testing machine with a 50-N load cell at a crosshead speed of 0.5 mm/min. Microtensile bond strength values were recorded in MPa and compared by Analysis of Variance and the post hoc Tukey test (a = 0.05). RESULTS: In enamel, Clearfil SE Bond presented the highest values, followed by Adper Single Bond 2, AdheSE and Adper Scotch Bond Multi Purpose, without significant difference. The highest values in dentin were obtained with Adper Scotch Bond Multi Purpose and all other adhesives did not present significant different values from that, except Adper Prompt L-Pop that achieved the lowest bond strength in both substrates. Adper Scotch Bond Multi Purpose and Adper Single Bond 2 presented significantly lower values in enamel than in dentin although all other adhesives presented similar results in both substrates. CONCLUSIONS: contemporary adhesive systems present similar behaviors when bonded to primary teeth, with the exception of the one-step self-etching system; and self-etching systems can achieve bond strength values as good in enamel as in dentin of primary teeth.     

Bond strength of self-etch adhesives to dentin prepared with three different diamond burs.

OBJECTIVES: To evaluate the micro-tensile bond strength (mu TBS) of a control etch-and-rinse and three self-etch (strong, mild, ultra-mild) adhesive systems to dentin prepared with three different grit size of diamond burs. METHODS: Dentin surfaces were created from mid-coronal sound dentin in extracted, human third molars. The teeth were ground with high-speed medium grit (100 microm), fine grit (30 microm), or extra-fine grit (15 microm) diamond bur. Resin composite (Z100) was bonded to the surfaces using Optibond FL, Adper Prompt L-Pop, Clearfil SE Bond, or Clearfil S3 Bond. Rectangular micro-specimens were prepared using the slow-speed diamond saw and tested in tensile to determine the mu TBS. Failure analysis was performed using a stereo-microscope and Fe-SEM. Data were analyzed by two-way analysis of variance and Tukey's HSD test (p<0.05). RESULTS: The etch-and-rinse adhesive yielded high micro-tensile values (58-69 MPa), irrespective of the diamond burs used. The bond strength values were comparable for Adper Prompt L-Pop and Clearfil SE Bond irrespective of the burs used. The mu TBS values were significantly higher as the particle size of diamond burs is smaller for Clearfil S3 Bond. Most failures were recorded as interfacial failure when the fine and extra-fine diamond burs were used. SIGNIFICANCE: Overall, different grit-sized diamond burs did not affect the mechanical properties of the interface, except for the ultra-mild one step self-etch adhesive. This adhesive performed significantly better when a smaller grit size was used to prepare dentin surface.     

Bond strength of composite to dentin using conventional, one-step, and self-etching adhesive systems

OBJECTIVES: This in vitro study compared the dentin bonding performance of eight adhesive systems using a microtensile bond strength test. METHODS: Thirty bovine teeth were ground to 600-grit to obtain flat root-dentin surfaces. Two conventional adhesive systems (Scotchbond Multipurpose Plus, OptiBond FL), four one-step adhesive systems (Scotchbond 1, Asba S.A.C., Prime and Bond NT, Excite) and two self-etching adhesive materials (Clearfil Liner Bond 2 V and Prompt L-Pop) were evaluated. Each bonding system was applied according to manufacturer's instructions and followed by composite (Z100) application. Immediately after bonding, the teeth were prepared for microtensile testing. Bond strength to dentin was measured using a Vitrodyne V-1000 universal tester. There were 14 replicates for each material. Fractured specimens were further observed by SEM. RESULTS: Scotchbond Multipurpose Plus exhibited significantly (p<0.05) higher bond strength values (30.3+/-9.4 MPa) than all other materials. The bond strengths of the other materials were (from highest to lowest): Opitbond FL (22.4+/-4.3 MPa); Scotchbond 1(18.9+/-3.2); Clearfil Liner Bond 2 V (18.9+/-3.0); Prime and Bond NT (18.3+/-6.9); Asba S.A.C. (14.4+/-2.9); Excite (13.8+/-3.7); and Prompt L-Pop (9.1+/-3.3). Statistical comparisons frequently overlapped, but Optibond was significantly (p<0.05) greater than Asba, Excite, and Prompt L-Pop; whereas, Scotchbond 1 was only significantly (p<0.05) greater than Prompt L-Pop. Asba, Excite and Prompt L-Pop were not significantly different. The fracture modes were mostly adhesive. CONCLUSIONS: The conventional adhesive systems produced higher bond strengths to root dentin than most one-step adhesives and one self-etching adhesive; with the exception of one material in each respective system.     

In vitro permeability of etch-and-rinse and self-etch adhesives used for immediate dentin sealing

To investigate the permeability of deep dentin following immediate sealing with different etch-and-rinse and self-etch adhesives (Single Bond 2, Adper Prompt L-Pop, Clearfil Protect Bond, Clearfil S3 Bond, G-Bond) and a dentin desensitizer (Gluma). Fluid-transport model was used to measure fluid conductance during and after application of adhesives. Polyvinylsiloxane impressions of bonded dentin were taken to monitor fluid transudation from the surface of the adhesives. The area and number of dentinal fluid droplets and/or blisters were calculated using image analysis. None of the adhesives were able to block fluid conductance completely. The fluid conductance values of the adhesives displayed the following statistical ranking (p<0.05): G-Bond≤Clearfil Protect Bond相似文献