Three-year clinical evaluation of a two-step self-etch adhesive with or without selective enamel etching in non-carious cervical sclerotic lesions

Objective

The purpose of this prospective, controlled, randomized study was to evaluate the 3-year clinical performance of a two-step self-etch adhesive (AdheSE, Ivoclar Vivadent; Schaan, Liechtenstein) in non-carious cervical sclerotic lesions with or without selective acid-etching of the enamel margins.

Material and methods

Twenty-two patients (mean age 51.5) having at least two pairs of non-carious cervical sclerotic erosion?attrition?abfraction lesions with incisal or occlusal margins in the enamel and gingival margins in the dentin were included in the study. The two-step self-etch adhesive was applied following either the self-etch approach (AdheSE non-etch, n?=?52) or a similar application approach, including prior selective acid-etching of the enamel margins (AdheSE etch, n?=?52). Composite resin Point 4 (Kerr Corp; Orange, CA, USA) was used as the restorative material for all 104 restorations. The restorations were evaluated at baseline and after 1, 2, and 3 years, according to the modified USPHS criteria. Data were analyzed using McNemar’s test (p?<?0.05).

Results

The retention rates for AdheSE non-etch were 100 %, 98 %, and 91.5 %; whereas, 100 %, 100 %, and 97.9 % retention rates were recorded for AdheSE etch after 1, 2, and 3 years, respectively. No significant differences were detected between the retention rates, marginal adaptation at the dentin side, secondary caries, and postoperative sensitivity (p?>?0.05). A significantly higher number of restorations in AdheSE non-etch group showed clinically acceptable slight marginal discoloration (p?=?0.0001) and clinically acceptable small marginal defects at the enamel side (p?=?0.008) than in the AdheSE etch group.

Conclusions

After 3 years, the two-step self-etch adhesive exhibited acceptable clinical performance with or without selective enamel etching in non-carious cervical sclerotic lesions.

Clinical relevance

Selective acid-etching of the enamel margins enhanced the performance of the two-step self-etch adhesive in terms of marginal discoloration and marginal adaptation at the enamel side.     

Proximal direct composite restorations and chairside CAD/CAM inlays: Marginal adaptation of a two-step self-etch adhesive with and without selective enamel conditioning

The aim of this study was to evaluate the marginal adaptation of CEREC ceramic inlays, CEREC composite inlays and direct composite restorations in unbeveled proximal slot cavities under artificial aging conditions. Two groups of each restoration type were prepared (n = 6), one group with a self-etch adhesive, the other group with H₃PO₄ enamel etching before the self-etch adhesive application. Replicas were generated before and after long-term thermo-mechanical loading under dentinal fluid simulation and margins were evaluated at ×200 magnification in the scanning electron miscroscope (SEM). Statistically, significant differences were found before and after loading with respect to the percentages of “continuous margins”, the direct composite filling with H₃PO₄ enamel etching giving the lowest percentages of “continuous margins” after loading (p < 0.05). The highest percentage of “continuous margin” was attained by composite inlays without H₃PO₄ enamel etching. However, these results were not significantly different from ceramic inlays after stressing. Polymerization shrinkage is still one critical property of composite restorative materials. The marginal adaptation of indirect adhesive proximal slot restorations without enamel bevels both fabricated out of composite and ceramic is better than that of directly placed composite restorations. Clinical significance: Polymerization shrinkage is still one critical property of composite restorative materials. The marginal adaptation of indirect adhesive proximal slot restorations without enamel bevels both fabricated out of composite and ceramic is better than that of directly placed composite restorations.     

Three-year clinical effectiveness of a two-step self-etch adhesive in cervical lesions

A 3-yr randomized, controlled prospective study evaluated the clinical effectiveness of a mild two-step self-etch adhesive, Clearfil SE, in Class-V non-carious lesions. The hypothesis tested was that prior selective etching of enamel with phosphoric acid does not affect the 3-yr clinical performance of this adhesive. A total of 100 lesions in 29 patients were randomly restored in one or two pairs, according to two experimental protocols: (i) application of Clearfil SE according to the instructions of the manufacturer (C-SE non-etch); and (ii) similar application of Clearfil SE with prior etching of enamel cavity margins with phosphoric acid (C-SE etch). Clearfil AP-X was used as a restorative material. At 3 yr, 90% of the restorations were examined for retention, marginal integrity, marginal discoloration, caries recurrence, postoperative sensitivity, and preservation of tooth vitality. An excellent retention rate (100%) was noted after 3 yr of clinical functioning. Only one restoration of the C-SE etch group was clinically unacceptable owing to the presence of a severe cervical marginal defect. A pairwise comparison between both groups showed a significant difference only in the number of small marginal defects at the enamel side, which was higher in the C-SE non-etch group. These incisal defects were small and clinically irrelevant. Superficial marginal discoloration increased slightly in the C-SE non-etch group and was related to the higher frequency of small incisal marginal defects. In this latter group, localized marginal discoloration was observed significantly more in smokers. In conclusion, the clinical performance of the mild two-step self-etch adhesive, Clearfil SE, remained excellent after 3 yr of clinical functioning. Additional etching of the enamel cavity margins was not critical for its clinical performance.     

Clinical performance of a self-etch adhesive in Class V restorations made with and without acid etching

OBJECTIVES: To evaluate the clinical performance of a self-etching adhesive in Class V carious lesions with and without acid etching procedures. METHODS: A total of 183 Class V carious cavities with incisal margins in enamel and gingival margins in cementum were selected and restored with Futurabond NR self-etch adhesive and resin composite Grandio. Restorations were made using three different techniques; after etching of the enamel, after etching the whole cavity for 20s and without acid etching (control). The restorations were evaluated at baseline, 1 and 2 years using USPHS criteria. RESULTS: No loss of restorations was recorded after 1 and 2 years for all the three restorative techniques. There was no significant difference between the baseline and 2-year results for any of the tested technique. However, restorations made after acid etching showed less marginal discoloration at the enamel margins. CONCLUSION: The clinical performance of Futurabond NR self-etch adhesive was excellent after 2 years. Acid etching of the enamel margin or the whole cavity did not improve the overall quality of the restorations, but displayed less marginal discoloration.     

Influence of acid etching and enamel beveling on the 6-month clinical performance of a self-etch dentin adhesive

This study tested the hypothesis that beveling and/or etching enamel does not affect the 6-month clinical performance of the self-etch adhesive Clearfil SE Bond in class V noncarious lesions. With Institutional Review Board approval, 34 patients were enrolled in this study. A total of 120 noncarious cervical lesions were selected and assigned to 4 groups: (1) Clearfil SE Bond was applied without any cavity preparation; (2) After the enamel was beveled, Clearfil SE Bond was applied; (3) After the enamel was etched for 15 seconds with 35% phosphoric acid, Clearfil SE Bond was applied; (4) After the enamel was beveled and etched with 35% phosphoric acid for 15 seconds, Clearfil SE Bond was applied. A microfilled composite resin was used for all restorations. Six months after initial placement, 120 restorations (a 100% recall rate) were re-evaluated. Retention rates at 6 months were 100% for all groups. Sensitivity to air improved from baseline to 6 months, but the overall difference was not statistically significant. The 6-month retention rate of the self etch dentin adhesive system Clearfil SE Bond was not improved by enamel beveling or by enamel etching. For the self-etch material Clearfil SE Bond, instrumentation or etching of enamel may not be critical for its clinical performance at 6 months.     

Fatigue testing of enamel bonds with self-etch and total-etch adhesive systems.

OBJECTIVE: Etching of enamel by self-etching adhesive systems is not as pronounced as with phosphoric acid employed with most total-etch adhesive systems. This may result in differences in the effectiveness of the bonds for the two types of systems. The aim of this study was to compare two such systems by bond strength and fatigue testing. MATERIALS AND METHODS: Shear bond strengths for Single Bond (SB) and Adper Prompt-L-Pop (PLP) were obtained on bovine enamel surfaces. Fatigue measurements were made with the same test fixtures using cyclical loading at 2 Hz for a maximum of 10(5) cycles or until the bond failed. Four selected loads between 40 and 70% of the shear bond strength were tested for each adhesive and the number of cycles to failure was recorded. S-N curves were constructed from the data and fatigue stress limits were determined. The Mann-Whitney U-test and t-tests were used for statistical comparisons of the results. SEM analysis of resin tag formation into enamel surfaces was carried out. RESULTS: A significantly greater bond strength was found for SB (25.3 MPa) than for PLP (19.2). Sustainable stresses after 10(5) load cycles were substantially lower than the corresponding shear bond strengths and fatigue limits were found to be 8.4 MPa for PLP and 14.6 MPa for SB. The ratio of fatigue limit to bond strength was less for PLP (44%) than for SB (57%). Resin tag penetration into enamel was substantially less for PLP than for SB. SIGNIFICANCE: Fatigue testing in conjunction with bond strength testing can provide a better means for assessing the performance of adhesive systems used for bonding to enamel.     

Bond strengths of one- and two-step self-etch adhesive systems

STATEMENT OF PROBLEM: One-bottle self-etching adhesives have been introduced that combine the etchant, primer, and adhesive into a single bottle in an effort to reduce the number of bonding steps. Limited research has been conducted comparing the efficacy of 1-bottle and 2-bottle self-etching adhesives. PURPOSE: This investigation evaluated the microtensile bond strength (MTBS) of 3 one-step self-etching adhesives, 2 two-step self-etching adhesives, and a total-etch adhesive. A secondary objective was to evaluate the effect of an intermediary layer of elastic resin on the MTBS of 2 of the self-etching adhesives. MATERIAL AND METHODS: The MTBS of 3 one-step self-etching adhesives (G-Bond, iBond, and Clearfil S(3)), 2 two-step self-etching adhesives (Clearfil SE and Optibond Solo Plus Self-Etch), and a total-etch adhesive (Prime & Bond NT) was evaluated. Microtensile bond strength (MPa) was determined using composite resin (Herculite XRV) cylinders bonded to the dentin surface of human third molars (n=24) using 6 bonding agents. Each bonded tooth specimen was longitudinally sectioned to produce bar-shaped specimens with a square cross-sectional nominal bond area of 1.4 mm(2) (n=20). Bonded specimens were stored in distilled water at 37 degrees C +/- 2 degrees C for 72 hours, during which time they were subjected to thermal cycling (1500 cycles, in water baths of 5 degrees C and 55 degrees C, for a dwell time of 30 seconds). Testing was performed on a universal testing machine at a crosshead speed of 1.0 mm/min. One-way ANOVA, Ryan-Einot-Gabriel-Welsh multiple range test, and Wald chi square test, each using an overall alpha=.05, were performed on all data. Low-power (x20) microscopic examination of the bond failure was observed for each specimen. RESULTS: The 1-way ANOVA (P<.001) and Ryan-Einot-Gabriel-Welsh multiple range test (P<.05) showed significant differences between the mean MTBS values for several of the bonding agents tested. The Wald chi square test of the Weibull distribution showed significant differences between adhesives (P<.001). CONCLUSION: Of the bonding agents tested, significantly higher MTBS was obtained with the total-etch 2-stage adhesive. The results of this study suggest that there are similar bond strengths between the 1- and 2-bottle self-etch adhesives.     

Micro-shear bond strengths and etching efficacy of a two-step self-etching adhesive system to fluorosed and non-fluorosed enamel

The purpose of this study was to evaluate the micro-shear bond strengths and the etching efficacy of a two-step self-etching adhesive system to fluorosed and non-fluorosed enamel. The extracted teeth, obtained from Australian and Japanese patients, were classified according to the severity of fluorosis, using the Thylstrup & Fejerskov index (TFI). Australian teeth were classified as mildly fluorosed (TFI = 1–3), whereas Japanese teeth were classified as non-fluorosed (TFI = 0). Resin composite was bonded to 20 enamel samples using Clearfil SE bond. The bonded samples were stressed at a crosshead speed of 1 mm min⁻¹ to determine the micro-shear bond strength. To examine the etching efficacy of primer on fluorosed and non-fluorosed enamel, the enamel-surface pH values were directly measured using a micro pH sensor. The non-fluorosed enamel showed significantly higher bond strengths compared with the fluorosed enamel. There was a statistical difference between fluorosed and non-fluorosed enamel regarding the surface pH change before and after application of the Clearfil SE bond primer. The results from this study suggest that water fluoridation has an effect on the acid resistance of enamel surfaces when treated with a two-step self-etching adhesive system and that this effect leads to reduced bond strengths.     

Durability of enamel bonding using two-step self-etch systems on ground and unground enamel

This study examined the early and long-term microtensile bond strengths (MTBS) and interfacial enamel gap formation (IGW) of two-step self-etch systems to unground and ground enamel. Resin composite (Filtek Z250) buildups were bonded to proximal enamel surfaces (unground, bur-cut or SiC-treated enamel) of third molars after the application of four self-etch adhesives: a mild (Clearfil SE Bond [SE]), two moderate (Optibond Solo Plus Self-Etch Primer [SO] and AdheSE [AD]) and a strong adhesive (Tyrian Self Priming Etchant + One Step Plus [TY]) and two etch-and-rinse adhesive systems (Single Bond [SB] and Scotchbond Multi-Purpose Plus [SBMP]). Ten tooth halves were assigned for each adhesive. After storage in water (24 hours/37 degrees C), the bonded specimens were sectioned into beams (0.9 mm2) and subjected to microTBS (0.5 mm/minute) or interfacial gap width measurement (stereomicroscope at 400x) either immediately (IM) or after 12 months (12M) of water storage. The data were analyzed by three-way repeated measures ANOVA and Tukey's test (alpha=0.05). No gap formation was observed in any experimental condition. The microTBS in the Si-C paper and diamond bur groups were similar and greater than the unground group only for the moderate self-etch systems (SO and AD). No reductions in bond strength values were observed after 12 months of water storage, regardless of the adhesive evaluated.     

Effect of pre-etching enamel on fatigue of self-etch adhesive bonds.

OBJECTIVE: A previous study found that the shear bond strength (SBS) to bovine enamel for the self-etching adhesive Adper Prompt-L-Pop (PLP) was 75% of that found with the etch-and-rinse material SingleBond, while the comparative value for the shear fatigue limit (SFL) was only 58% at 10(5) load cycles. Resin penetration into the enamel surface was substantially less for PLP but it was not conclusive that this was the reason for the lower results cited above. The objective of this study was to determine if pre-etching enamel would substantially improve the SBS and SFL of the PLP adhesive over those found in the previous study. MATERIALS AND METHODS: All test methods were the same as for the previous study. SBS measurements were conducted for composite bonds to bovine enamel using a phosphoric acid pre-etch with the PLP adhesive (PLP-10) and for a conventional enamel-bonding adhesive (EB). Fatigue testing was done with the same test fixtures, load cycling at 2Hz up to a maximum of 10(5) cycles at four selected peak load values between 35 and 60% of the respective bond strengths. Fatigue limits were determined from the data obtained. SEM analysis of resin penetration of the enamel surface was carried out for each adhesive. RESULTS: A significantly greater SBS and SFL were found for EB (SBS: 30.4MPa; SFL: 15.6MPa) than for PLP-10 (SBS: 20.2MPa; SFL: 9.9MPa). Compared with previously found results, the pre-etching of enamel had no significant improvement in SBS and only slight improvement in SFL. Resin tag penetration of the enamel surface for PLP-10 was similar to that previously found for PLP alone, suggesting that the porosity created by phosphoric acid was effectively removed by the acidic PLP adhesive. SIGNIFICANCE: Unlike some self-etching adhesives reported in the literature, pre-etching enamel did not improve the performance of the Prompt-L-Pop adhesive.     

Bond strength of a mild self-etch adhesive with and without prior acid-etching

SUMMARY: The self-etch approach provides dentists with a generation of user-friendly and less technique-sensitive adhesives. Nevertheless, some concern has been raised regarding their bonding effectiveness to enamel, in particular when so-called 'mild' self-etch adhesives are employed. OBJECTIVES: The purpose of this study was to test the hypothesis that the two-step self-etch adhesive Clearfil SE Bond (C-SE; Kuraray, Osaka, Japan) bonds equally effective to enamel/dentin either with or without prior etching with phosphoric acid. METHODS: Bur-cut enamel/dentin surfaces prepared from human molars were partially split in two halves by cutting a shallow groove. One half was first etched with 40% phosphoric acid (K-etchant), while protecting the other half by holding a razor blade in the groove. Next, C-SE was applied strictly following the manufacturer's instructions, after which the surface was built up using Z100 (3M Espe). After 24-h water storage, micro-specimens were prepared with the interface circularly constricted using a Micro-Specimen Former, prior to micro-tensile bond strength (MPa) measurement. In addition, interfaces of C-SE with enamel/dentin prepared with and without beforehand acid etching were examined by Feg-SEM and TEM. RESULTS: Beforehand etching significantly increased the bonding effectiveness of C-SE to enamel. A clearly more micro-retentive surface was revealed by TEM and Feg-SEM when enamel was etched. Phosphoric-acid etching prior to C-SE application on dentin significantly decreased the muTBS to dentin. TEM provided indications of a low-quality hybrid layer after beforehand phosphoric-acid etching. CONCLUSION: Using C-SE, additional etching with phosphoric acid to improve bonding effectiveness should be limited to enamel.     

操作经验对自酸蚀粘接剂与牙釉质粘接强度的影响

目的 研究操作人员的操作经验对白酸蚀粘接剂与牙釉质及磷酸酸蚀后牙釉质粘接强度的影响.方法 对90颗牛切牙进行牙体预备,暴露牙釉质粘接面,平均分给3组人员:无操作经验组(A组)、4年操作经验组(B组)和10年操作经验组(C组).每组又进一步分为非酸蚀亚组和预酸蚀亚组.非酸蚀亚组采用白酸蚀粘接剂和复合树脂进行牙釉质粘接,预酸蚀组预先使用磷酸酸蚀剂进行酸蚀处理,然后按照非酸蚀亚组的步骤粘接.测试粘接试样的抗剪切强度,即粘接强度,并进行单因素方差分析.结果 对于非酸蚀试样,A组[(16.32±5.99)MPa]与B组[(21.36± 4.07) MPa]粘接强度的差异有统计学意义(P =0.006),而A组与C组[(18.77±3.78) MPa]的差异无统计学意义(P=0.163);对于预酸蚀试样,A组[(21.34±5.62)MPa]与B组[(26.18± 3.57) MPa](P=0.007)、A组与C组[(25.35 ±4.51) MPa] (P=0.023)粘接强度的差异均有统计学意义.无论是非酸蚀试样,还是预酸蚀试样,B组与C组粘接强度的差异均无统计学意义(P=0.140和0.672).具有操作经验人员操作后的粘接强度高于没有操作经验的学生.此外,3组操作人员的非酸蚀亚组与预酸蚀亚组之间的差异均有统计学意义(A组P=0.025、B组P=0.002、C组P=0.000).预酸蚀处理增加了白酸蚀粘接剂与牙釉质的粘接强度.结论 操作经验对粘接强度有显著影响.为了获得最佳的粘接效果,不仅需要具有粘接理论基础知识,同时还需要一定的操作经验,并应严格按照说明书要求操作.     

Five-year clinical effectiveness of a two-step self-etching adhesive

PURPOSE: The purpose of this prospective randomized controlled clinical study was to evaluate the clinical performance of a "mild" two-step self-etching adhesive, Clearfil SE, in Class V restorations after 5 years of clinical functioning. MATERIALS AND METHODS: Twenty-nine patients received two or four restorations following two randomly assigned experimental protocols: (1) a mild self-etching adhesive (Clearfil SE, Kuraray) was applied following manufacturer's instructions on both enamel and dentin (C-SE non-etch); (2) similar application of Clearfil SE, but including prior selective acid-etching of the enamel cavity margins with 40% phosphoric acid (C-SE etch). Clearfil AP-X (Kuraray) was used as the restorative composite for all 100 restorations. The clinical effectiveness was recorded in terms of retention, marginal integrity, marginal discoloration, caries recurrence, postoperative sensitivity, and preservation of tooth vitality after 5 years of clinical service. The hypothesis tested was that selective acid etching of enamel with phosphoric acid improved retention, marginal integrity, and clinical microleakage of Class V restorations. RESULTS: Only one restoration of the C-SE non-etch group was lost at the 5-year recall. All other restorations were clinically acceptable. Marginal integrity deteriorated with time in both groups. The number of restorations with defect-free margins was significantly lower in the C-SE non-etch group (p = 0.0043). This latter group presented significantly more small incisal marginal defects on the enamel side (p = 0.0169). Superficial marginal discoloration increased in both groups, but was more pronounced in the C-SE non-etch group and was related to the higher frequency of small incisal marginal defects. CONCLUSION: The clinical effectiveness of the two-step self-etching adhesive Clearfil SE remained excellent after 5 years of clinical service. Additional etching of the enamel cavity margins resulted in an improved marginal adaptation on the enamel side; however, this was not critical for the overall clinical performance of the restorations.     

Improving the performance of EndoREZ root canal sealer with a dual-cured two-step self-etch adhesive. II. Apical and coronal seal

This study tested the hypothesis that the seal of EndoREZ may be improved with an adhesive-modified technique. Instrumented single-rooted teeth were filled with: (a) Warm vertical compaction with AH Plus (control); (b). EndoREZ with master cones and passive application of accessory cones; (c) Application of Clearfil Liner Bond 2V before EndoREZ and gutta-percha condensation. Leakage was assessed by fluid filtration at 10 psi before root resection and after 3 to 12 mm apical resections. Statistical analyses revealed significant differences in filling technique and resection lengths. EndoREZ exhibited significantly higher overall leakage, while no difference was found between AH Plus and the adhesive-modified EndoRez technique. Apical resection of EndoREZ to 12 mm exhibited more leakage than all other interactions, but was not significantly different from the same material resected to 9 mm. Although EndoREZ exhibited an acceptable apical seal, its coronal seal may be improved with the use of a dual-cured self-etch adhesive.     

Influence of phosphoric acid etching on microleakage of a self-etch adhesive and a self-adhering composite

Background: The aim of this study was to evaluate the influence of preliminary phosphoric acid etching on the microleakage of a self‐adhering flowable composite and a self‐etch adhesive used in combination with the proprietary flowable composite. Methods: Standard Class V cavities were prepared on the buccal side of 20 extracted sound human molars. Specimens were randomly divided into five groups: (1) Gel Etchant/Optibond FL/Premise Flowable; (2) Vertise Flow; (3) Optibond XTR/Premise Flowable; (4) Gel Etchant/Vertise Flow; and (5) Gel Etchant/Optibond XTR/Premise Flowable (Kerr). The interfacial sealing ability of the materials was evaluated by scoring the depth of silver nitrate penetration and through scanning electron microscopy observations. Differences in leakage at either the enamel or the dentine interface were evaluated for statistical significance (Kruskal–Wallis ANOVA, Mann–Whitney U test, p < 0.05). Results: At the enamel interface, no significant differences were found among the materials. On dentine, Gel Etchant/Vertise Flow had the highest leakage scores and the difference was statistically significant (p < 0.05). Conclusions: The early sealing ability of the self‐adhering flowable composite and the self‐etch adhesive in Class V restorations did not significantly benefit from selective enamel etching. Preliminary phosphoric acid etching of dentine negatively affected the quality of the seal when using the adhesive‐free flowable composite.