An 18-months' evaluation of self-etch and etch & rinse adhesive in non-carious cervical lesions

OBJECTIVE. In this intra-individual comparison (an 18-months' randomized, controlled prospective study), we evaluated the clinical performance of one self-etch and one "etch & rinse" adhesive in non-carious cervical lesions. METHODS. Twenty-five patients with at least two pairs of similar-sized non-carious cervical lesions participated. Seventy-eight restorations were placed; 39 with etch & rinse (Single-Bond) and 39 with self-etch (Adper Prompt). Both adhesives were combined with the microfilled resin composite Filtek-A110. The restorations were evaluated at baseline, 6, 12, and 18 months according to slightly modified USPHS criteria. Statistical differences between the adhesives was tested with McNemar's test and clinical degradation over time for each material with the Fisher exact test (a=0.05). RESULTS. Thirty pairs were evaluated at 12 and 18 months. Two self-etch restorations were lost after 18 months. Nine Adper Prompt and four Single-Bond restorations scored bravo for marginal adaptation at 18 months (p<0.05). Nine Adper Prompt and three Single-Bond restorations scored bravo for marginal discoloration (p<0.05). CONCLUSIONS. Both adhesive systems showed acceptable clinical retention rates according to the ADA full acceptance criteria for enamel-bonding systems in class V non-carious lesions. The self-etch adhesive showed a faster progressive marginal degradation.     

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.     

A randomized controlled clinical trial of a HEMA-free all-in-one adhesive in non-carious cervical lesions at 1 year

OBJECTIVES: One-step self-etch adhesives are the most recent generation of adhesives introduced onto the market. The objective of this randomized controlled clinical trial was to test the hypothesis that a one-step self-etch adhesive performs equally well as a conventional three-step etch&rinse adhesive (gold standard). METHODS: Fifty-two patients had 267 non-carious cervical lesions restored with Gradia Direct Anterior (GC). These composite restorations were bonded either with the 'all-in-one' adhesive G-Bond (GC) or with the three-step etch&rinse adhesive Optibond FL (Kerr). The restorations were evaluated after 6 and 12 months clinical service regarding their retention, marginal integrity and discoloration, caries occurrence, preservation of tooth vitality and post-operative sensitivity. Retention loss, severe marginal defects and/or discoloration that needed intervention (repair or replacement) and the occurrence of caries were considered as clinical failures. A logistic regression analysis with generalized estimating equations was used to account for the clustered data (multiple restorations per patient). RESULTS: The recall rate at 1 year was 98%. The statistical analysis revealed a relatively low patient factor, indicating that supplementary information could be obtained from the additional restorations placed per patient. The retention rate for G-Bond was 98.5% compared to 99.3% for Optibond FL, due to the retention loss of two and one restorations, respectively. There were no significant differences between the two adhesives regarding the evaluated parameters except for the presence of small enamel marginal defects with G-Bond. CONCLUSIONS: After 12 months, the simplified one-step G-Bond and the three-step Optibond FL were clinically equally successful, even though both adhesives were characterized by progressive degradation of marginal adaptation, and G-Bond exhibited more small enamel marginal defects.     

自酸蚀和酸蚀-冲洗粘结剂对Ⅰ类洞复合树脂充填的2年临床评价

目的:评价酸蚀-冲洗粘结剂和自酸蚀粘结剂在后牙I类洞修复中的临床效果。方法:共25名后牙患龋的患者入选了本次临床试验。每位患者随机接受了至少2颗后牙I类洞的修复,68例患牙随机分为2组,实验组采用自酸蚀粘结剂+复合纳米树脂修复(Adper Easy One+Filtek Z350,3M ESPE)38例,对照组使用全酸蚀牙本质粘结剂+复合纳米树脂修复(Adper Single Bond 2+Filtek Z350,3MESPE)30例。在充填后即刻、术后6个月、1年和2年时,根据改良的USPHS量表,从保存率、术后敏感、颜色匹配、边缘染色、边缘完整性、解剖形态、继发龋和表面质地7个方面对每个修复体都进行评分。结果:在复查的2年内,全酸蚀和自酸蚀组的保存率分别为100%和90.6%,其他各项指标亦均无显著性差异。结论:自酸蚀粘结剂和全酸蚀粘结剂用于修复后牙Ⅰ类洞均可获得较理想的临床效果。     

The effect of five different universal adhesives on the clinical success of class I restorations: 24-month clinical follow-up

Objectives

The aim of this study was to evaluate the 24-month clinical performance of universal adhesives on the restoration success of Class I carious lesions.

Materials and methods

Five different universal adhesives (Gluma Bond Universal (GU), Clearfil Universal (CU), Prime&Bond Elect Universal (PU), All bond Universal (AU), and Single Bond Universal (SU)) were used in the self-etch and etch-and-rinse modes in 42 patients. The study was conducted with 10 groups, with 20 restorations in each group. The restorations were evaluated at baseline and during a 24-month recall using World Dental Federation (FDI) and the US Public Health Service (USPHS) criteria. The changes in the parameters were analyzed using the chi-square test.

Results

At the end of 24 months, there was no loss of restoration in any group. According to the USPHS, there was no difference in the baseline and 24-month clinical behavior of the restorations (P ˃ 0.05). However, according to the FDI, when adhesives were used in the self-etch mode, three adhesives (GU, SU, PU) showed marginal incompatibility, and one adhesive showed (GU) marginal discoloration between baseline and the 24-month follow-up evaluation (P < 0.05). There was no significant difference after 24 months between etch-and-rinse and self-etch groups according to the results based on both the USPHS and FDI criteria (P ˃ 0.05).

Conclusions

The 24-month clinical performance of the evaluated universal adhesives depends on the adhesive strategy.

Clinical relevance

This study helps clinicians to decide in which mode (etch-and-rinse or self-etch) universal adhesives can be safely used.

     

Clinical effectiveness of a one-step self-etch adhesive in non-carious cervical lesions at 2 years

A 2-year randomized, controlled prospective study evaluated the clinical effectiveness of a one-step self-etch adhesive and a “gold-standard” three-step etch-and-rinse adhesive in non-carious Class-V lesions. The null hypothesis tested was that the one-step self-etch adhesive does perform clinically equally well as the three-step etch-and-rinse adhesive. A total of 161 lesions in 26 patients were restored with Clearfil AP-X (Kuraray). The restorations were bonded either with the “all-in-one” adhesive Clearfil S3 Bond (Kuraray) or with the three-step etch-and-rinse adhesive Optibond FL (Kerr). The restorations were evaluated at baseline and after 6 months, 1 and 2 years, regarding their retention, marginal adapation, marginal discoloration, caries occurrence, preservation of tooth vitality and post-operative sensivity. Retention loss, severe marginal defects and/or discoloration that needed intervention (repair or replacement) and the occurrence of caries were considered as clinical failures. The recall rate at 2 years was 93.8%. Only one Clearfil S3 Bond restoration was lost at the 2-year recall. All other restorations were clinically acceptable. The number of restorations with defect-free margins decreased severely during the 2-year study period (to 6.7% and 25.3% for Clearfil S3 Bond and Optibond FL, respectively). The Clearfil S3 Bond restorations presented significantly more small marginal defects at the enamel side than the Optibond FL restorations (Clearfil S3 Bond: 93.3%; Optibond FL: 73.3%; p = 0.000). Superficial marginal discoloration increased in both groups (to 53.3% and 36% for Clearfil S3 Bond and Optibond FL, respectively) and was also more pronounced in the Clearfil S3 Bond group (p = 0.007). After 2 years, the simplified one-step self-etch adhesive Clearfil S3 Bond and the three-step etch-and-rinse adhesive Optibond FL were clinically equally successful, even though both adhesives were characterized by progressive degradation in marginal integrity. Clearfil S3 Bond exhibited more small enamel marginal defects and superficial marginal discolorations.

     

A clinical evaluation of a resin composite and a compomer in non-carious Class V lesions. A 3-year follow-up

PURPOSE: To compare the clinical performance of a resin composite and a polyacid-modified resin composite (compomer) in non-carious cervical lesions using a one-step self-etch adhesive. METHODS: Thirty patients, each with two non-carious cervical lesions (60 restorations), received one composite (Pertac-II) restoration and one compomer (Hytac) restoration, both used in conjunction with a self-etch adhesive (Prompt L-Pop) and placed following the manufacturer's instructions. Evaluations were at baseline, 6, 12 and 36 months after placement for retention, margin adaptation, marginal discoloration, anatomic form, secondary caries and postoperative sensitivity. Statistical analysis with the Pearson Chi-square test was undertaken. RESULTS: Retention rates were 86.6% for composite and 86.7% for compomer at 36 months. 3.3% of composite and 6.7% of compomer restorations showed a deficiency in marginal adaptation. Both materials showed a slight marginal discoloration of 7.7%. More deterioration in anatomic form occurred with the compomer (11.5%) than the composite (3.8%). None of the restorations exhibited secondary caries or postoperative sensitivity problems. There was no significant difference in performance between the materials in any of the categories evaluated.     

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.     

Three-year clinical performance of a HEMA-free one-step self-etch adhesive in non-carious cervical lesions

Despite the fact that one-step adhesives are currently used routinely in clinical practice, long-term studies on their clinical performance are scarce. The objective of this randomized controlled clinical trial was to test the hypothesis that a 2-hydroxyethyl methacrylate (HEMA)-free one-step self-etch adhesive performs worse than a conventional multistep etch-and-rinse adhesive. Two-hundred and seventy-six non-carious cervical lesions in 52 patients were restored with a micro-hybrid composite (Gradia Direct; GC). These restorations were bonded in random order either with the HEMA-free one-step adhesive G-Bond (GC) or with the 'gold-standard' (control) three-step adhesive Optibond FL (Kerr). The restorations were evaluated after 6, 12, 24, and 36 months of clinical service regarding retention, marginal adaptation, microleakage, caries occurrence, and sensitivity. After a medium-long period of 3 yr, similar success in clinical performance was observed for the simplified all-in-one adhesive and the conventional three-step adhesive. However, the one-step adhesive exhibited significantly more incisal marginal defects and discolorations. Whereas marginal degradation appeared to arrest for the multistep etch-and-rinse adhesive after 12 months, the enamel margins of the restorations bonded with the one-step self-etch adhesive continued to deteriorate. These incisal marginal defects were, however, small and could easily be removed by polishing. For both adhesives, large and sclerosed lesions appeared to be at higher risk of retention loss.     

三种粘接剂粘接不同牙本质的微拉伸粘接强度比较

目的采用微拉伸粘接强度实验测定3种牙本质粘接剂粘接楔状缺损处硬化牙本质的粘接强度。方法选择有典型楔状缺损并因牙周病拔除的上颌前磨牙30颗作为实验组，正常上颌前磨牙30颗作为对照组，使用粘接剂A（全酸蚀粘接剂Scotchbond Multi—Purpose）、B（一步法自酸蚀粘接剂Adper Prompt L-Pop）和C（两步法自酸蚀粘接剂Contax）处理硬化牙本质和正常牙本质表面，相应树脂修复。测试两组试件的微拉伸粘接强度。结果粘接剂A、B、C粘接硬化牙本质的微拉伸粘接强度分别为46．805MPa、39．045MPa、29．852MPa。粘接剂A和C与硬化牙本质的微拉伸粘接强度低于正常牙本质，而粘接剂B与之相反，差异有统计学意义（P〈0．05）。结论牙颈部楔状缺损处硬化牙本质由于结构上的特殊性可造成粘接困难。酸性强有利于粘接剂与硬化牙本质的粘接。     

Adhesives for the restoration of non-carious cervical lesions: a systematic review

ObjectivesTo establish whether simplified adhesives (self-etch) are as clinically effective as conventional adhesives (etch-and-rinse) with multiple application steps for treatment of non-carious cervical lesions (NCCLs).Null hypothesis: there is no difference in the clinical effectiveness of the four different bonding strategies: Three-step etch-and-rinse; Two-step etch-and-rinse; Two-step self-etch; One-step self-etch for treatment of NCCLs.SourcesElectronic databases were searched including: Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. In addition, studies were identified by handsearching of selected journals.Study selectionRandomised controlled trials (RCTs) comparing at least two adhesives in non-carious cervical lesions (NCCLs), with at least 18 months follow-up were selected. The primary outcome was loss of retention/restoration loss, with marginal adaptation and marginal discolouration as secondary outcomes. Criteria for quality assessment included: random sequence generation; allocation concealment; blinding of outcome assessment; and information on withdrawals. Twenty six studies were identified that met the inclusion criteria. In general, studies were not of sufficient quality to fully address the objectives of this review.ConclusionThere is not enough evidence to support one adhesive or bonding strategy over another for treatment of NCCLs. Consequently, the null hypothesis of no difference cannot be supported or rejected with the data currently available. There is a need for better standardisation and reporting of randomised controlled trials investigating adhesive performance.Clinical significanceStudies with low overall risk of bias demonstrated good clinical performance for adhesives with all four bonding strategies. However, included studies showed wide variation between adhesives of the same category.     

Microleakage after thermocycling of 4 etch and rinse and 3 self-etch adhesives with and without a flowable composite lining

This study evaluated the microleakage of composite fillings prepared with 4 etch and rinse and 3 self-etch adhesive systems after thermocycling. Also evaluated was the potential improvement of cavity sealing when utilizing a low charged resin lining for cavity preparations. Seventy recently extracted teeth were randomly allocated to 7 experimental adhesive systems: two 3-step etch and rinse adhesive systems, Scotchbond Multipurpose (SBMP) and Optibond Solo Plus (OS); two 2-step etch and rinse adhesive systems, referred to as "one-bottle," Scotchbond 1 (SB1) and Gluma Comfort Bond + Desensitizer (G); and 3 self-etch "all-in-one" adhesives, Adper Prompt-L-Pop (PLP), Xeno III (X-III) and iBond (iB). On each tooth, 2 rectangular cavities were prepared at the cemento-enamel junction: 1 cavity was prepared with adhesive and the hybrid composite and the second was filled with the same adhesive and a thin layer of flowable composite (Filtek Flow) under the resin composite (Z100). All teeth were thermocycled for 800 cycles (5 degrees C-55 degrees C, 30 seconds dwell time). Leakage was evaluated on a 6-point (0-5) severity scale for enamel and dentin on 4 interfaces for each restoration. The results are expressed as means +/- standard deviation (SD). Microleakage scores were analyzed by means of generalized linear mixed models (GLMM), assuming an ordinal logistic link function. Covariates in the model were: (1) adhesives, (2) fluid composite and (3) interface. The model also accounts for repeated measurements on the various teeth. The authors found that the mean score of microleakage per tooth was significantly higher at the enamel rather than at the dentin interfaces (1.21 +/- 0.51 and 0.87 +/- 0.48; p<0.0001). In this study, there was no significant difference among the 4 etch and rinse adhesive systems. On the other hand, these adhesives yielded smaller mean scores of microleakage than the 3 self-etch systems (respectively, 0.85 +/- 0.2 and 1.3 +/- 0.5; p<0.0001). Among the self-etch adhesives, microleakage was significantly greater for PLP (1.74 +/- 0.46) than for the other self-etch products (p<0.0001), while X-III, an intermediary strong self-etch, was found to be as good as the etch and rinse systems, with a mean score of 0.97 +/- 0.27. In addition, results have also shown that an under layer of flowable composite significantly improved the water tightness of the PLP adhesive restorations (p=0.042). This in vitro study concluded that the self-etch adhesives remain less effective than etch and rinse. Nevertheless, X-III, a self-etch adhesive, showed acceptable performance in accordance with this study's 6-point severity scale of microleakage, but this needs to be confirmed in further clinical studies. On the other hand, this study failed to reveal that the addition of a thin layer of fluid composite improved the water tightness of the restoration, except for PLP.     

48-month clinical evaluation of a copper-containing universal adhesive in non-carious cervical lesions: A double-blind randomised clinical trial

ObjectivesThis study aimed to evaluate the effect of copper nanoparticles (CuNp) on the clinical performance of a universal adhesive system used as an etch-and-rinse or self-etch strategy.MethodsA total of 216 class V (non-carious lesions) restorations were randomly placed in 36 subjects according to the following groups: ERcu, adhesive in etch-and-rinse with 0.1% CuNp; ERct, adhesive in etch-and-rinse without CuNp; SEcu, adhesive in self-etch with 0.1% CuNp; and Sect, adhesive in self-etch without CuNp. Restorations were evaluated at baseline and at 6, 12, 18, 36, and 48 months, using the FDI and USPHS criteria. Appropriate statistical analyses were performed (α = 0.05).ResultsAfter 48 months, 14 restorations were lost (two for ERcu, five for SEcu, and seven for SEct) and the retention rates (95% confidence interval [CI]) were 74.1% for ERcu (95% CI 61.1–83.8); 81.5% for ERct (95% CI 69.2–89.6); 64.8% (95% CI 51.5–76.2) for SEcu; and 64.8% (95% CI 51.5–76.2) for SEct, with statistical differences between SEct vs. ERct and SEcu vs. ERct (p < 0.05). No significant differences between the groups were observed when the secondary parameters were evaluated (p > 0.05). Nineteen restorations (two for ERcu, two for ERct, six for SEcu, and nine for SEct) showed minor marginal staining, and 44 restorations (7 for ERcu, 8 for ERct, 14 for SEcu, and 15 for SEct) presented minimal marginal adaptation defects.SignificanceThis is the first long-term clinical trial to show that the addition of CuNp to a universal adhesive system does not affect clinical performance.     

Eighteen-month clinical evaluation of a new universal adhesive applied in the “no-waiting” technique: a randomized clinical trial

Objective

The aim of this double-blind, randomized clinical trial was to evaluate the 6- and 18-month clinical performances of a new universal adhesive applied in the “no-waiting” (NW) technique to non-carious cervical lesions (NCCLs) using two evaluation criteria.

Materials and methods

One hundred and seventy-six restorations were assigned to four groups according to the adhesive system, adhesive strategy, and application mode: Prime&Bond Active (PB) applied using the etch-and-rinse (ER) and self-etch (SE) strategies with 20 s applications and Clearfil Universal Bond Quick (CQ) applied using the ER and SE strategies with the NW technique. The composite resin restorations were evaluated at baseline and after 6 and 18 months using the World Dental Federation (FDI) and US Public Health Service (USPHS) criteria. The Friedman repeated measures analysis of variance and Wilcoxon test were used for statistical analyses (α?=?0.05).

Results

No significant differences were observed among any of the groups or criteria after 6 months (p?>?0.05). After 18 months, 10 restorations were lost (p?>?0.05) (2 with PB-ER [95.5%; 95%CI: 92–100%], 4 with PB-SE [90.9%; 95%CI: 82–98%], 0 with CQ-ER [100%; 95%CI: 92–100%], and 4 with CQ-SE [90.9%; 82–98%]). The restorations performed with the SE strategy showed more marginal discrepancies than those performed with the ER strategy, mainly when the FDI criteria were used (p?<?0.05). Those that used the PB-SE showed fewer marginal discrepancies than those that used the CQ-SE (FDI; p?<?0.05). A few restorations showed marginal discrepancies after the USPHS analysis (p?>?0.05).

Conclusions

The results when using the CQ-SE and -ER strategies with the NW technique were similar to those when using the PB-SE and -ER strategies in standard applications to non-carious cervical lesions after 6 and 18 months of clinical evaluation.

Clinical relevance

After 6 and 18 months, the application of Clearfil Universal Bond Quick with the “no-waiting” technique showed similar clinical performance compared to the standard application of Prime & Bond Active applied using the standard application time (20 s).

Trial registration

ClinicalTrials.gov identifier RBR-5f9gps.

     

One-day bonding effectiveness of new self-etch adhesives to bur-cut enamel and dentin

Self-etch adhesives try to solve difficulties commonly associated with the clinical application of etch-and-rinse adhesives. Their application procedure is considered less time-consuming and, more importantly, less technique-sensitive. The main objective of this study was to determine the bonding effectiveness to and the interaction with enamel/dentin of three contemporary one- and two-step self-etch adhesives by microtensile bond strength testing (microTBS), Fe-SEM and TEM when compared to a control two-step self-etch and a three-step etch-and-rinse adhesive. The one-step self-etch adhesive, Adper Prompt (3M ESPE), scored the lowest microTBS of all experimental and control adhesives tested. Conversely, the two-step self-etch adhesives Clearfil SE (Kuraray) and OptiBond Solo Plus Self-Etch (Kerr) approached the values obtained by the three-step etch-and-rinse control (OptiBond FL, Kerr) when bonded to enamel and dentin. Ultramorphological characterization showed that interfacial morphology and the pH of the self-etch primer/adhesive are strongly associated. The interaction with dentin varied from the formation of a submicron, hydroxyapatite-containing hybrid layer for the "mild" self-etch adhesive Clearfil SE to a 3-5 microm thick, hydroxyapatite-depleted hybrid layer for the "strong" self-etch adhesive Adper Prompt. The two-step self-etch adhesives AdheSE and OptiBond Solo Plus Self-Etch presented with a hybrid layer with a hydroxyapatite-depleted top part and a hydroxyapatite-containing base part and were therefore classified into a new group of self-etch adhesives, namely "intermediary strong" self-etch adhesives.     

In vitro bonding performance of self-etch adhesives: II--ultramorphological evaluation

OBJECTIVE: To study the interfacial ultra-morphology formed by "all-in-one" self-etch adhesives. METHODS: Forty-nine extracted molars were assigned to one of five all-in-one adhesives: Adper Prompt L-Pop (AP, 3M ESPE); Clearfil S3 Bond (S3, Kuraray); G-Bond (GB, GC America); iBond (iB, Heraeus Kulzer) and Xeno IV (XE, Dentsply Caulk). Adper Single Bond Plus (SB, 3M ESPE), a two-step etch&rinse adhesive, and Clearfil SE Bond (SE, Kuraray), a two-step self-etch adhesive, were used as controls. Dentin, unground enamel and ground enamel were used as bonding substrates. Dentin specimens were processed for FESEM and TEM analyses. Enamel specimens were processed for FESEM. RESULTS: Dentin: GB, iB, S3, SE and XE resulted in a submicron-thick hybrid layer (0.2-0.7 microm), but only S3 and SE did not result in interfacial gaps. AP resulted in the thickest hybrid layer (1.7-2.9 microm) among the self-etch adhesives. SB resulted in a 3.4-5.2 pm thick hybrid layer. Unground enamel-GB, iB and SE resulted in a mostly featureless morphology resembling that of untreated enamel with areas in which the superficial enamel layer was removed without dissolving the subsurface enamel. XE resulted in areas of intra-prismatic etching and areas without any etching pattern. S3 resulted in frequent shallow intra-prismatic etching, while AP was able to unveil the enamel crystallites across the entire enamel surface. Phosphoric acid in SB resulted in the deepest intra- and inter-prismatic demineralization. Ground enamel--AP resulted in a well-defined inter-prismatic etching pattern. iB, GB, SE and S3 resulted in islands of superficially dissolved enamel within areas without evidence of enamel dissolution. XE resulted in etched enamel areas with mild intraprismatic exposure of crystallites. Phosphoric acid in SB resulted in deep enamel etching. CONCLUSIONS: Only AP, an aggressive self-etch adhesive, showed enamel morphological features that resemble those created by etch & rinse adhesives. S3 and SE were the only self-etch adhesives that did not result in dentin interfacial debonding.     

Five-year clinical performance of a silorane- vs a methacrylate-based composite combined with two different adhesive approaches

Objectives

The objective of this study was to compare the 5-year clinical performance in posterior restorations of three restorative systems including a low-shrinkage system and a methacrylate-based composite combined either with an etch-and-rinse or a self-etch adhesive.

Materials and methods

Each of 25 patients received three class I (occlusal) or class II restorations performed with each one of the three restorative systems: Filtek Silorane Restorative System including a two-step self-etch adhesive, Adper Scotchbond 1 XT (two-step etch-and-rinse adhesive) + Filtek Z250, and Adper Scotchbond SE (two-step self-etch adhesive) + Filtek Z250. All materials were applied as per manufacturer’s instructions. Two blind observers evaluated the restorations at four different moments (baseline, after 1, 2, and 5 years) according to the USPHS-modified criteria. Kruskal-Wallis and Mann-Whitney U tests were conducted to compare the behavior of the restorative systems, while Friedman and Wilcoxon tests were applied to analyze the intrasystem data (p < 0.05).

Results

After 5 years, marginal staining around the restorations with Adper Scotchbond SE + Filtek Z250 was statistically more frequent and severe than that of the restorations performed with the other two systems. Intrasystem comparisons revealed a deterioration of the marginal adaptation after 5 years for all systems. A significant number of restorations bonded with self-etch adhesives showed marginal staining after 5 years of clinical service. A deterioration of the color appearance and an increase of the surface roughness were also detected in the restorations performed with Adper Scotchbond SE + Filtek Z250.

Conclusions

A deterioration of the marginal adaptation was evidenced for all restorative systems, while marginal staining was more frequently seen only around the restorations performed with self-etch adhesives.

Clinical relevance

No advantage was found of the silorane- over the methacrylate-based composite when combined with an etch-and-rinse adhesive.

     

Self-etch vs etch-and-rinse adhesives: effect of thermo-mechanical fatigue loading on marginal quality of bonded resin composite restorations.

OBJECTIVE: This study evaluated the marginal integrity of dentine adhesives bonded to enamel and dentine, before and after thermo-mechanical loading (TML). METHODS: MO cavities with proximal boxes beneath the CEJ were prepared in extracted human third molars. Direct resin composite restorations (Tetric Ceram) were bonded with 3-step etch-and-rinse (Syntac Classic, Solobond Plus, OptiBond FL), 2-step etch-and-rinse (Admira Bond, Single Bond), 2-step self-etch (AdheSE, Clearfil SE Bond), and 1-step self-etch (all-in-one) adhesives (Adper Prompt, Xeno III, iBond). Marginal gaps were analyzed using SEM of epoxy resin replicas. Bonded interfaces before TML were examined with TEM to identify pre-existing attributes for subsequent marginal disintegration. RESULTS: In enamel, high percentages of gap-free margins were initially identified for all adhesives. After TML, etch-and-rinse adhesives exhibited significantly higher percentages of gap-free margins (approximately 90%) compared with two-step self-etch (approximately 75%) and all-in-one (approximately 55%) adhesives (p<0.05). iBond did not completely etch through the enamel smear layer. In dentine, 89-100% gap-free margins were initially observed. After TML, there were no statistical differences among etch-and-rinse (62-70%) and two-step self-etch (62-63%) adhesives (p>0.05). The all-in-one adhesives exhibited significantly less gap-free margins (<40%) in dentine (p<0.05), with iBond showing the worst marginal integrity (15%). The presence of pre-existing water channels within the adhesives probably expedited water sorption when restorations were under functional stresses. CONCLUSION: Enamel bonding was more effective with phosphoric acid-etching. Etch-and-rinse and 2-step self-etch adhesives showed promising marginal adaptation to dentine and may have a better clinical prognosis than the all-in-one bonding approach.     

Fatigue of enamel bonds with self-etch adhesives

ObjectiveFatigue testing of adhesive bonds to tooth structures in conjunction with bond strength testing can provide more useful information for examining the effectiveness of dental adhesives. The purpose of this study was to determine the shear bond strength (SBS) and shear fatigue limit (SFL) of composite to enamel bonds using modern adhesive systems.MethodsTwelve specimens each were used to determine 24-h resin composite (Z100-3M ESPE) to enamel shear bond strengths with an etch-and-rinse system (ERA), Adper Single Bond Plus (SB), and four self-etch adhesives (SEA)—Adper Prompt-L-Pop (PLP), Clearfil SE (CSE), Clearfil S³ (CS3) and Xeno IV (X4). A staircase method of fatigue testing was used in a four-station fatigue cycler to determine the SFL of composite to enamel bonds with the adhesives (16–20 specimens for each adhesive) at 0.25 Hz for 40,000 cycles. ANOVA and Tukey's post hoc test were used for the SBS data and a modified t-test with Bonferroni correction was used for comparisons of the SFL.ResultsThe SBS and SFL of the etch-and-rinse system were significantly greater (p < 0.05) than those of the four self-etch adhesives. The SBS and SFL of CSE were also significantly greater than for the other three self-etch systems. The ratio of SFL to SBS was highest with the etch-and-rinse system and the ratio became increasing smaller in the same order that the values for SBS decreased with the self-etch systems.SignificanceThe lower fatigue limits for composite to enamel bonds obtained with the self-etch adhesive systems may indicate that greater enamel margin breakdown will occur with restorations where these systems are used for bonding.