Long-term dentin retention of etch-and-rinse and self-etch adhesives and a resin-modified glass ionomer cement in non-carious cervical lesions.

OBJECTIVES: The aim of this study was to evaluate the clinical long-term retention to dentin of seven adhesive systems. METHODS: A total of 270 Class V restorations of four etch-and-rinse, one self-etch adhesive system and a resin-modified glass ionomer cement were placed in non-carious cervical lesions without intentional enamel involvement. The restorations were evaluated at baseline, 6, 12, 18, and 24 months and then every year during a 13-year follow-up. Dentin bonding efficiency was determined by the percentage of lost restorations. RESULTS: During the 13 years, 215 restorations could be evaluated. The cumulative loss rate at 13 years was 53.0%, with significant different failures rates for the different systems varying between 35.6 and 86.8%. Four systems fulfilled the ADA 18-month full acceptance retention criteria. Two systems showed at 18 months and earlier high debonding rates. The annual failure rates for the etch-and-rinse systems were Optibond 3.1%, Permagen 13.0%, Scotchbond MP 4.8%, Syntac classic 2.8%; for the self-etch system P&S 4.4%; and the resin-modified glass ionomer cement Vitremer 2.7%. CONCLUSION: It can be concluded that all systems showed a continuous degradation of the bond with a wide variation, which was independent of the adhesion strategy. Three bonding systems showed a cumulative failure rate after 13 years between 36 and 41% with the best retention for the resin-modified glass ionomer cement and a four-step etch-and-rinse system.     

Retention of tooth-colored restorations in non-carious cervical lesions—a systematic review

Objectives

The aim of this review was to assess the effect of different adhesive systems and tooth preparation on the retention of tooth-colored restorative materials placed in non-carious cervical lesions (NCCLs).

Methods

Randomized clinical trials with a minimum of 3 years of follow-up that evaluated the effectiveness of tooth-colored materials, adhesive systems, and preparation techniques for the restoration of NCCLs were selected. The Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE (OVID), the Latin American and Caribbean Health Sciences Literature database (LILACS), and Medline (OVID) electronic databases were searched from 1990 to 2013.

Results

Twenty-seven randomized clinical trials were included and reviewed. Meta-analysis was used to determine the relative risk of loss of tooth-colored NCCL restorations between different categories of adhesive systems. The effect of tooth preparation could not be similarly analyzed.

Conclusion

The current best evidence indicates that a glass ionomer cement has a significantly lower risk of loss of a NCCL restoration compared to either a three-step etch-and-rinse or a two-step etch-and-rinse adhesive system; a three-step etch-and-rinse adhesive system has a significantly lower risk of loss of a NCCL restoration compared to a two-step etch-and-rinse adhesive system. No significant difference could be observed in the risk of loss of a tooth-colored NCCL restoration between a three-step etch-and-rinse adhesive system and either a two-step self-etch or a one-step self-etch adhesive system.     

Clinical effectiveness of contemporary adhesives: a systematic review of current clinical trials.

OBJECTIVES: The purpose of this paper was to review current literature on the clinical effectiveness of contemporary adhesives when used to restore cervical non-carious class-V lesions. Restoration retention in function of time was recorded in order to find out if adhesives with a simplified application procedure are as clinically effective as conventional three-step adhesives. DATA SOURCES: Literature published from January 1998 up to May 2004 was reviewed for university-centred clinical trials that tested the clinical effectiveness of adhesives in non-carious class-V lesions. Restoration-retention rates per adhesive reported in peer-reviewed papers as well as IADR-AADR abstracts and ConsEuro abstracts were included and depicted as a function of time in graphs for each of the five adhesive classes (three- and two-step etch-and-rinse adhesives, two- and one-step self-etch adhesives, and glass-ionomers). The guidelines for dentin and enamel adhesive materials advanced by the American Dental Association were used as a reference. Per class, the annual failure rate (%) was calculated. Kruskal-Wallis analysis and Dwass-Steel-Chritchlow-Fligner pairwise comparisons were used to determine statistical differences between the annual failure percentages of the five adhesive categories. RESULTS: Comparison of retention of class-V adhesive restorations as a measure to determine clinical bonding effectiveness of adhesives revealed that glass-ionomers most effectively and durably bond to tooth tissue. Three-step etch-and-rinse adhesives and two-step self-etch adhesives showed a clinically reliable and predictably good clinical performance. The clinical effectiveness of two-step etch-and-rinse adhesives was less favourable, while an inefficient clinical performance was noted for the one-step self-etch adhesives. SIGNIFICANCE: Although there is a tendency towards adhesives with simplified application procedures, simplification so far appears to induce loss of effectiveness. Clinical performance can be correlated with, and predicted by, appropriate types of laboratory study.     

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.     

Extension of a one-step self-etch adhesive into a multi-step adhesive.

One-step self-etch adhesives are undoubtedly the most user-friendly adhesives, but have been associated with lower bonding effectiveness as compared to two-step and three-step adhesives. Conversion of a one-step self-etch system into a two-step self-etch adhesive by adding a bonding step, or into a three-step etch&rinse adhesive by adding a beforehand etching step and a bonding step might be tempting in order to improve bond strength. OBJECTIVES: The objective of this study was to investigate whether adding application steps influences the bond strength of a one-step self-etch adhesive. METHODS: In this study, the bonding effectiveness of two experimental one-step self-etch adhesives and three different commercial adhesives to enamel and dentin was determined using a micro-tensile bond-strength protocol. This procedure was repeated for the experimental adhesives transformed into two-step self-etch and three-step etch&rinse adhesives. In addition, their interaction with tooth tissue was investigated using TEM and Feg-SEM. RESULTS: Transforming a one-step into a two-step self-etch adhesive did improve the bond strength to enamel and dentin, though not significantly. By adding a preceding etching step, the bond strength to enamel was significantly improved, but that to dentin was decreased considerably. The latter must be attributed to hampered resin infiltration of the one-step self-etch adhesive within the relatively deeply exposed collagen fibril network. SIGNIFICANCE: Additional application of a hydrophobic bonding agent slightly improved bonding effectiveness. Adding a preceding etching step is beneficial for enamel but should be avoided for dentin as this will decrease bond strengths, and may even jeopardize the bonding durability.     

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.

     

Clinical evaluation of three adhesive systems in class V non-carious lesions.

OBJECTIVES: The purpose of this study was to evaluate the clinical retention of three new adhesive systems in non-carious cervical lesions during a 3-year period. METHODS: The adhesive systems, a three-step (EBS/Pertac Hybrid), a one-bottle resin bonding agent (One-Step/Pertac Hybrid) and a resin-modified glass ionomer cement (Fuji II LC) were placed in 148 non-carious cervical lesions, 87 with sclerotic dentin and 61 non-sclerotic. Of the sclerotic lesions treated with the two resin bonding systems, 37 were slightly roughened with a diamond bur before conditioning. The restorations were evaluated every 6 months during a 3-year period. RESULTS: All except six restorations were evaluated during the 3 years. The cumulative loss rates for EBS, One-Step and Fuji II LC were, at 1 year: 2, 24 and 2% and at 3 years: 10, 49, 7%, respectively. The one-bottle adhesive showed significantly more failures. The five lost EBS restorations were found in non-sclerotic lesions, while the three lost Fuji II LC restorations had been placed in sclerotic lesions. For the One-Step material the loss frequency for non-sclerotic versus sclerotic lesions was 31.8 and 65.2%, respectively. Slight roughening of the sclerotic dentin surfaces with a diamond bur did not increase retention of the restorations. SIGNIFICANCE: The three-step resin adhesive and the RMGIC showed clinically acceptable retention rates, while a high failure rate was registered for the one-bottle adhesive.     

OPTIONS FOR DENTIN/ENAMEL BONDING: PART I

Four categories of resin-based dentin/enamel adhesives are currently available. These include the three-step etch-and-rinse, "one-bottle" etch-and-rinse, two-step self-etch primer systems, and "all-in-one" self-etch adhesives. In consecutive issues of the Journal, the Critical Appraisal series will present salient publications on research in each of the categories, beginning with this issue's piece on the three-step etch-and-rinse systems.     

Long-term bonding to eroded dentin requires superficial bur preparation

Objectives

This study aims to evaluate the influence of different surface preparation techniques on long-term bonding effectiveness to eroded dentin.

Materials and methods

Dentin specimens were eroded by pH cycling or were left untreated as control, respectively. Five different “preparation” techniques were applied: (1) cleaning with pumice, (2) air abrasion, (3) silicon polisher, (4) proxo-shape, and (5) diamond bur. The three-step etch-and-rinse adhesive OptiBond FL (O-FL; Kerr) and the mild two-step self-etch adhesive Clearfil SE Bond (C-SE; Kuraray) were evaluated. Micro-tensile bond strength was measured after water storage for 24?h and 1?year. Fracture analysis was performed by stereomicroscopy and SEM. Interfaces were characterized by TEM. Differences were statistically analyzed with a linear mixed effects model (α?=?0.05).

Results

Erosion reduced bond strength in all groups, but this effect was less prominent when eroded dentin was prepared by diamond bur. Storage lowered bond strength in almost all groups significantly, but this ageing effect was more prominent for the eroded surfaces than for non-eroded controls. Whereas after 1-year control specimens revealed superior bond strength with the three-step etch-and-rinse adhesive (O-FL), the mild two-step self-etch adhesive (C-SE) revealed a better 1-year bond strength to eroded dentin. The interface at eroded dentin appeared very prone to degradation as was shown by the increased amount of adhesive failures and by the silver infiltration detected by TEM.

Conclusions and clinical relevance

Although a minimally invasive approach should clinically always be strived for, superficial preparation (or minimal roughening) with a diamond bur is recommendable for long-term bonding to eroded dentin.     

Dental adhesion review: aging and stability of the bonded interface.

OBJECTIVE: Most of current dental adhesive systems show favorable immediate results in terms of retention and sealing of bonded interface, thereby counteracting polymerization shrinkage that affects resin-based restorative materials. Despite immediate efficacy, there are major concerns when dentin bonded interfaces are tested after aging even for short time period, i.e. 6 months. METHODS: This study critically discusses the latest peer-reviewed reports related to formation, aging and stability of resin bonding, focusing on the micro and nano-phenomena related to adhesive interface degradation. RESULTS: Most simplified one-step adhesives were shown to be the least durable, while three-step etch-and-rinse and two-step self-etch adhesives continue to show the highest performances, as reported in the overwhelming majority of studies. In other words, a simplification of clinical application procedures is done to the detriment of bonding efficacy. Among the different aging phenomena occurring at the dentin bonded interfaces, some are considered pivotal in degrading the hybrid layer, particularly if simplified adhesives are used. Insufficient resin impregnation of dentin, high permeability of the bonded interface, sub-optimal polymerization, phase separation and activation of endogenous collagenolytic enzymes are some of the recently reported factors that reduce the longevity of the bonded interface. SIGNIFICANCE: In order to overcome these problems, recent studies indicated that (1) resin impregnation techniques should be improved, particularly for two-step etch-and-rinse adhesives; (2) the use of conventional multi-step adhesives is recommended, since they involve the use of a hydrophobic coating of nonsolvated resin; (3) extended curing time should be considered to reduce permeability and allow a better polymerization of the adhesive film; (4) proteases inhibitors as additional primer should be used to increase the stability of the collagens fibrils within the hybrid layer inhibiting the intrinsic collagenolytic activity of human dentin.     

Restoring cervical lesions with flexible composites.

OBJECTIVES: Flexure at the tooth cervix has been suggested to dislodge cervical restorations more rapidly. The objective of this randomized controlled clinical trial was to test the hypothesis that a higher composite flexibility better withstands tooth flexure stress. METHODS: One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of the three experimental groups: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ/A-Hy, Ultradent), (2) Permaquick applied with the more flexible micro-filled composite Amelogen Microfill (PMQ/A-Mi, Ultradent), or (3) the 'golden standard' three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (O-FL/Pro, Kerr). RESULTS: The recall rate at 7 years was 80%. No statistically significant difference was found for any of the parameters evaluated neither between both adhesives, nor between both composites (McNemar, p>0.05). Eleven percent of the O-FL/Pro restorations were clinically unacceptable due to loss of retention (5.5%) and severe marginal discoloration (5.5%). In the PMQ-group, 22% of the PMQ/A-Mi restorations (8% loss of retention, 5% severe enamel margin defects, 3% severe dentin margin defects, 6% severe marginal discoloration, 3% extreme sensitivity) and 19% of the PMQ/A-Hy restorations (13% loss of retention, 3% severe enamel margin defects, 3% severe marginal discoloration) needed repair or replacement. SIGNIFICANCE: The clinical performance of the three adhesive/composite combinations was good and reliable during the 7-year clinical trial. It was concluded that the composite stiffness does not affect the clinical longevity of cervical composite restorations.     

Effect of operator skill in relation to microleakage of total-etch and self-etch bonding systems

OBJECTIVES: To evaluate the influence of operator skill on microleakage in class V restorations using two-step bonding systems. METHODS: Two standardized box cavities were made on the buccal and lingual surfaces of 54 human bicuspid teeth, with the cervical margin in dentin. The teeth were randomly assigned to two groups according to the operator's skill. Students group: undergraduate students. Expert group: a dentist with 20 years of clinical experience in dental adhesion. The buccal cavities of each tooth were treated with Prime&Bond NT (two-step total-etch system); the lingual cavities were treated with AdheSE (two-step self-etch system). All cavities were restored by a single calibrated operator with one bulk increment of resin composite (InTens; Ivoclar Vivadent). Specimens were thermocycled, immersed in 2% methylene blue and sectioned in a bucco-lingual plane in the middle of the restorations. They were then examined under a stereomicroscope and scored according to microleakage by two operators who were blind to the specimen preparation. The data was subjected to a multilevel statistical model. RESULTS: The microleakage resulting from the self-etch adhesive was similar in the student and in the expert groups. On the other hand, the total-etch adhesive microleakage within the expert group resulted lower than that within the student group. However, the interaction term skill x adhesive resulted statistically significant at the dentin margin (p=0.0474) but not at the enamel margin (p=0.1267). CONCLUSION: While the total-etch adhesive used in this study showed to be skill-sensitive, the self-etch one proved to be less skill-sensitive in obtaining a reliable seal with dentin.     

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。     

Single-step, self-etch adhesives behave as permeable membranes after polymerization. Part III. Evidence from fluid conductance and artificial caries inhibition

PURPOSE: To test the hypothesis that formation of inhibition zones by bonded restorations in artificially-induced carious dentin lesions is related to the permeability of the self-etch adhesives. METHODS: Fluid conductance of four single-step self-etch adhesives (Prompt L-Pop, Etch&Prime 3.0, One-Up Bond F and Reactmer Bond), and a control two-step self-etch adhesive (UniFil Bond) were measured after sound dentin surfaces were:(1) acid-etched; (2) polished to produce smear layers; (3) bonded with the adhesive; each at 20 cm hydrostatic pressure (hp). Osmotic fluid conductance was also determined for the bonded dentin after immersion in 4.8 M CaCl2 at 0 cm hp. For artificial caries inhibition, a non-fluoride releasing (NFR) two-step self-etch adhesive (UniFil Bond) and a fluoride-releasing (FR) single-step adhesive (Reactmer Bond) were used in combination with a NFR composite (Metafil CX) or a FR restorative material (Reactmer Paste). Artificial caries were induced in these restorations, from which 120 +/- 10 microm thick sections and the effect of caries inhibition were quantitatively assessed with polarizing light microscopy and image analysis. RESULTS: Fluid conductance after bonding with the single-step adhesives Prompt L-Pop and Etch&Prime 3.0 were not significantly different from those recorded from smear layer-covered dentin. Although better seals were achieved with One-Up Bond F and Reactmer Bond, fluid conductance at 20 cm hp was significantly higher than the two-step self-etch adhesive UniFil Bond. Osmotic conductance at 0 cm hp were not significantly different from normal fluid conductance at 20 cm hp. The sizes of artificial carious lesions in UniFil Bond were significantly higher irrespective of whether a FR or NFR composite was used. Significant reduction in lesion size occurred in Reactmer Bond with the use of a NFR composite, and even more so with the use of a FR composite.     

Application of a dental adhesive using the self-etch and etch-and-rinse approaches: an 18-month clinical evaluation

BACKGROUND: Laboratory investigations have demonstrated that the application of multiple adhesive coats can increase adhesive infiltration, thereby increasing bond strength values. The authors conducted an 18-month, randomized, controlled prospective study to evaluate the clinical performance of a self-etch and an etch-and-rinse adhesive in noncarious cervical lesions. METHODS: Twenty-nine patients with at least two pairs of similarly sized lesions participated in this study. The authors placed 116 restorations in one of four groups: OS2 (phosphoric acid and dental adhesive [One-Step Plus, Bisco, Schaumburg, Ill.], following the manufacturer's recommendation [two coats]); OS4 (phosphoric acid and One-Step Plus, with four coats); TY2 (Tyrian SPE [Bisco] and One-Step Plus, following the manufacturer's recommendation [two coats]); and TY4 (Tyrian SPE and One-Step Plus, with four coats). The authors evaluated the restorations at baseline and at six, 12 and 18 months, according to modified U.S. Public Health Service criteria. (Eight of the 116 restorations were unavailable for follow-up.) RESULTS: The retention rate for the TY2 group (55.5 percent) was statistically lower than that for the TY4 (77.8 percent) and OS4 (88.9 percent) groups. Only teeth in OS4 exhibited a retention rate at 18 months that was similar to that observed at baseline. Marginal discoloration occurred in all groups, and it was statistically significantly worse in TY2. CONCLUSIONS: Multiple adhesive coats significantly improved retention rates. CLINICAL IMPLICATIONS: Applying multiple coats of adhesive with the etch-and-rinse or self-etch approach can improve retention rates of Class V resin-based composite restorations, although not to the level of the American Dental Association's guidelines for dentin and adhesive materials.     

Bond strength of glass-ceramics on the fluorosed enamel surfaces

OBJECTIVES: Effect of different adhesive luting systems on the shear bond strength of IPS Empress 2 ceramic restorations to fluorosed enamel surface was investigated. METHODS: Forty-eight ceramic discs (2 mm x 3 mm; IPS Empress 2) were fabricated. Twenty-four non-carious extracted human molar teeth with fluorosis and 24 without fluorosis were cleaned with pumice using a plastic brush and then they were divided into two main groups. The IPS Empress 2 ceramic discs were luted to the teeth of four subgroups with two different adhesive luting systems, Variolink 2/Excite DSC (etch-and-rinse) and Clearfil Esthetic Cement/ED Primer II (self-etch), thermocycling was performed 5000 times. Shear bond strengths were tested using Shimadzu Universal Testing Machine until failure. An optical microscope and image analyzer were used at 10x and 1000x magnification to analyze the surfaces for adhesive, cohesive and mixed failure percentages. Data was analyzed with one-way ANOVA and Tukey test at a significance level of p<0.05. RESULTS: Mean shear bond strength data of the groups in MPa were; Variolink 2/Excite DSC on fluorosed enamel: 18.3+/-3.08, Variolink 2/Excite DSC on non-fluorosed enamel: 18.79+/-2.65, Clearfil Esthetic Cement/ED Primer II on fluorosed enamel: 8.43+/-2.45, Clearfil Esthetic Cement/ED Primer II on non-fluorosed enamel: 13.53+/-1.68. Mixed failure was the most prevalent type of failure in moderate fluorosed and non-fluorosed teeth with etch-and-rinse dentin bonding system, and in fluorosed teeth with self-etch dentin bonding system. CONCLUSIONS: The use of an etch-and-rinse adhesive luting procedure produced higher bond strengths of glass-ceramics bonded to fluorosed and non-fluorosed enamel surfaces than the self-etch bonding system.     

A randomized controlled 5-year prospective study of two HEMA-free adhesives,a 1-step self etching and a 3-step etch-and-rinse,in non-carious cervical lesions

Objective

The aim of this study was to evaluate the 5 year clinical dentin bonding effectiveness of two HEMA-free adhesives in Class V non-carious cervical lesions.

Material and methods

A total of 169 Class V restorations were placed in 67 patients with a self-etching adhesive (G-Bond; 67), a 3-step HEMA and TEGDMA free etch-and-rinse (cfm; 51) and a control HEMA-containing etch-and-rinse adhesive (XP Bond; 51) in non-carious cervical lesions without intentional enamel involvement. The restorations were evaluated at baseline and yearly during a 5 year follow-up with modified USPHS criteria. Dentin bonding efficiency was determined by the percentage of lost restorations.

Results

During the 5 years, 159 restorations could be evaluated. Good short time dentin retention was observed for the three adhesives, there all adhesives fulfilled at 18 months the full acceptance ADA criteria. At 5 years a cumulative number of 22 lost restorations (13.8%) was observed. The HEMA-free adhesives showed significantly higher dentin retention compared to the HEMA-containing one. Loss of retention was observed for 5 G-Bond (7.9%), 4 cfm (8.3%) and 13 XP Bond (27.1%) restorations (p < 0.05). No post-operative sensitivity was reported by the participants. No secondary caries was observed.

Significance

The durability in non-carious cervical lesions of the HEMA-free adhesives was successful after 5 years. Despite concerns which have been raised, showed the 1-step SEA one of the best reported clinical dentin bonding effectiveness.     

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.     

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.

     

Adhesive systems: important aspects related to their composition and clinical use

This literature review article addresses the types and the main components of different etch-and-rinse and self-etch adhesive systems available in the market, and relates them to their function, possible chemical interactions and influence of handling characteristics. Scanning electron microscopy (SEM) images are presented to characterize the interface between adhesives and dentin. Adhesive systems have been recently classified according to their adhesion approaches in etch-and-rinse, self-etch and glass ionomer. The etch-andrinse systems require a specific acid-etch procedure and may be performed in two or three steps. Self-etch systems employ acidic monomers that demineralize and impregnate dental substrates almost at the same time. These systems are separated in one or two steps. Some advantages and deficiencies were noted for etch-and-rinse and self-etch approaches, mainly for the simplified ones due to some chemical associations and interactions. The SeM micrographs illustrate different relationships between adhesive systems and dental structures, particularly dentin. The knowledge of composition, characteristics and mechanisms of adhesion of each adhesive system is of fundamental importance to permit the adoption of ideal bonding strategies under clinical conditions.