Two-year clinical effectiveness of adhesives and retention form on resin composite restorations of non-carious cervical lesions

Clinical Performance of Filled/Nanofilled Versus Nonfilled Adhesive Systems in Noncarious Cervical Lesions: A Systematic Review and Meta-analysis

CLINICAL RELEVANCE

The use of filled adhesive systems does not influence the clinical performance of the adhesive restoration in noncarious cervical lesions.

SUMMARY

Adhesive strategies in cervical lesions: systematic review and a network meta-analysis of randomized controlled trials

OBJECTIVES

A network meta-analysis (NMA) was performed to assess which adhesive strategy is most clinically effective in treating non-carious cervical lesions (NCCLs).

MATERIAL AND METHODS

Studies were identified by a systematic search of electronic databases including MEDLINE via PubMed, Brazilian Library in Dentistry (BBO), Cochrane Library, EMBASE, Latin American and Caribbean Health Sciences Literature database (LILACS), Scopus, and Web of Science without restrictions on publication year or language. The grey literature was also consulted. Only randomized clinical trials that compared different adhesive strategies in NCCLs in adult patients were included. The risk of bias was evaluated by using the Cochrane Collaboration tool. A random-effects Bayesian mixed treatment comparison model was used to compare adhesive strategies (3ER, 2ER, 2SE, and 1SE) at different follow-up times. The surface under cumulative ranking curve (SUCRA) was estimated for each strategy. Heterogeneity was assessed by using the Cochran Q test and I² statistics. The quality of evidence was evaluated using the GRADE approach.

RESULTS

A total of 5058 studies were identified, 66 of which met the eligibility criteria and of these 5 were judged "low" risk of bias and 57 were meta-analyzed. We did not observe significant differences in the NMA analysis for any two pairs of adhesives, except for the shortest follow-up for 2ER vs 3ER. The material 2SE ranked highest, although it differed only slightly from the other bonding strategies.

CONCLUSIONS

No bonding strategy is better than the others.

CLINICAL RELEVANCE

Adhesive efficacy cannot be characterized by its bonding strategy.

Current perspectives on dental adhesion: (1) Dentin adhesion - not there yet

The essential goal of any adhesive restoration is to achieve a tight and long-lasting adaptation of the restorative material to enamel and dentin. The key challenge for new dental adhesives is to be simultaneously effective on two dental substrates of conflicting nature. Some barriers must be overcome to accomplish this objective. While bonding to enamel by micromechanical interlocking of resin tags within the array of microporosities in acid-etched enamel can be reliably achieved and can effectively seal the restoration margins against leakage, bonding effectively and durably to organic and humid dentin is the most puzzling task in adhesive dentistry.

Much of the research and development of dental adhesives has focused on making the clinical procedure more user-friendly by reducing the number of bottles and/or steps. Although clinicians certainly prefer less complicated and more versatile adhesive materials, there is a trade-off between simplification of dental adhesives and clinical outcomes. Likewise, new materials are launched with claims of being novel and having special properties without much supporting evidence.

This review article discusses dental adhesion acknowledging pioneer work in the field, highlights the substrate as a major challenge to obtain durable adhesive restorations, as well as analyzes the three adhesion strategies and their shortcomings. It also reviews the potential of chemical/ionic dental adhesion, discusses the issue of extensively published laboratory research that does not translate to clinical relevance, and leaves a few thoughts in regard to recent research that may have implications for future adhesive materials.

Randomized clinical trial of four adhesion strategies: A 42 month study

Context

The adhesives clinical effectiveness has been extensively reported for noncarious cervical lesions (NCCLs). However, there is a lack of information about the adhesive systems strategies and their effect on NCCL restoration longevity.

Aims

This study aims to evaluate a 42-month performance of four dentin adhesive systems used for the restorative treatment of NCCLs.

Settings and Design

NCCLs were randomly divided into four groups: (1) Scotchbond multi-purpose (MP); 2: Single bond plus (SB); 3: Scotchbond SE (SE); and 4: Easy bond (EB).

Subjects and Methods

NCCLs (125) were randomly distributed: (1) MP; (2) SB; (3) SE; and (4) EB and were restored with a nanofilled resin-composite, evaluated along 18-36-42 months.

Statistical Analysis Used

Kruskal-Wallis test: Comparison among the adhesive systems in each period. Friedman analysis: Comparison along the periods. Kaplan-Meier: Survival analysis.

Results

Baseline and 42-month retention (RET) rates (%) were 100/100 for MP; 100/94.74 for SB; 100/87.5 for SE; and 100/100 for EB. The cumulative failure percentage was 9.52% for MP, 9.52% SB, 15.8% SE, and 10% EB. Restorations survival was not dependent on the used adhesive type. Marginal adaptation (MA) was similar to each group, but EB presented noticeable marginal deterioration. Wear was noticed in the 3-step etch-and-rinse (MP) restorations evaluated after 42 months. For the EB, baseline and 18-month wear evaluation were statistically similar. After 36 and 42 months, wear was also similar for EB.

Conclusions

Adhesive systems showed similar performance within most important adhesive bonding efficiency achievement parameters: RET, MA, interfacial staining, recurrent caries, and postoperative sensitivity evaluated during 42 months.

A 2-year clinical evaluation of direct and semi-direct resin composite restorations in non-carious cervical lesions: a randomized clinical study

OBJECTIVES

The purpose of this study was to evaluate the 2-year success of resin composite restorations in non-carious cervical lesions (NCCLs) using the direct or semi-direct techniques.

MATERIALS AND METHODS

Thirty volunteers presenting with at least two NCCLs were included. Each participant received one restoration using the direct technique and the other using the semi-direct technique, totaling 60 restorations. Time for completing the treatment was computed. Assessments at baseline, 7 days, and 6, 12, and 24 months were performed using the modified United States Public Health Service criteria. Descriptive analysis was reported as a percentage of successful treatments. For inferential analysis, the Student t test was used to evaluate the differences between extension, depth, and time. The chi-square/Fisher tests were used to compare treatment success after each period (α = 0.05). The results were evaluated by using the Kaplan-Meier survival analysis.

RESULTS

Differences were detected regarding mean ± standard deviation time, in which direct and semi-direct procedures were accomplished in 21.8 (± 14.5) and 35.3 (± 19.9) min, respectively. Of the 60 restorations placed, 7 failed in the direct group while 8 failed in the semi-direct group up to 2 years. No differences were detected between restorative protocols. The cumulative survival was 88.5% and 88.4% for the direct technique and semi-direct techniques after 24 months, respectively.

CONCLUSION

The tested restorative protocols present similar results for NCCLs within the studied periods.

CLINICAL RELEVANCE

The semi-direct technique exhibited clinical performance similar to direct technique for NCCL, demonstrating an alternative for restorations of these lesions.

Clinical Effectiveness of Different Polishing Systems and Self-Etch Adhesives in Class V Composite Resin Restorations: Two-Year Randomized Controlled Clinical Trial

The aim of this randomized controlled clinical trial was to compare the clinical effectiveness of different polishing systems and self-etch adhesives in class V composite resin restorations. A total of 164 noncarious cervical lesions (NCCLs) from 35 patients were randomly allocated to one of four experimental groups, each of which used a combination of polishing systems and adhesives. The two polishing systems used were Sof-Lex XT (Sof), a multistep abrasive disc, and Enhance/Pogo (EP), a simplified abrasive-impregnated rubber instrument. The adhesive systems were Clearfil SE bond (CS), a two-step self-etch adhesive, and Xeno V (XE), a one-step self-etch adhesive. All NCCLs were restored with light-cured microhybrid resin composites (Z250). Restorations were evaluated at baseline and at 6, 12, 18, and 24 months by two blinded independent examiners using modified FDI criteria. The Fisher exact test and generalized estimating equation analysis considering repeated measurements were performed to compare the outcomes between the polishing systems and adhesives. Three restorations were dislodged: two in CS/Sof and one in CS/EP. None of the restorations required any repair or retreatment except those showing retention loss. Sof was superior to EP with regard to surface luster, staining, and marginal adaptation (p<0.05). CS and XE did not show differences in any criteria (p>0.05). Sof is clinically superior to EP for polishing performance in class V composite resin restoration. XE demonstrates clinically equivalent bonding performance to CS.

Compliance of Randomized Clinical Trials in Noncarious Cervical Lesions With the CONSORT Statement: A Systematic Review of Methodology

The literature was reviewed to evaluate the compliance of randomized clinical trials (RCTs) with the CONsolidated Standards of Reporting Trials (CONSORT ) and the risk of bias of these studies through the Cochrane Collaboration risk of bias tool (CCRT). RCTs were searched at Cochrane Library, PubMed, and other electronic databases to find studies about adhesive systems for cervical lesions. The compliance of the articles with CONSORT was evaluated using the following scale: 0 = no description, 1 = poor description, and 2 = adequate description. Descriptive analyses about the number of studies by journal, follow-up period, country, and quality assessments were performed with CCRT for assessing risk of bias in RCTs. One hundred thirty-eight RCTs were left for assessment. More than 30% of the studies received scores of 0 or 1. Flow chart, effect size, allocation concealment, and sample size were more critical items, with 80% receiving a score of 0. The overall CONSORT score for the included studies was 15.0 ± 4.8 points, which represents 46.9% of the maximum CONSORT score. A significant difference among countries was observed (p&lt;0.001), as well as range of year (p&lt;0.001). Only 4.3% of the studies were judged as at low risk; 36.2% were classified as having unclear risk and 59.4% as having high risk of bias. The adherence of RCTs evaluating adhesive systems to the CONSORT is low with unclear/high risk of bias.

Influence of adhesive strategy on clinical parameters in cervical restorations: A systematic review and meta-analysis

OBJECTIVES

We aimed to answer the following PICO question: "Is the risk of postoperative sensitivity (POS), retention rates and marginal discoloration of composite restorations [CR] bonded with self-etch (SE) in non-carious cervical lesions (NCCLs) of adults equals to etch-and-rinse (ER) adhesives?".

METHODS

A comprehensive search was performed in May 2016 in the MEDLINE, Scopus, Web of Science, LILACS, BBO and Cochrane Library and SIGLE, abstracts of IADR, unpublished and ongoing trials registries, dissertations and theses without restrictions. Only randomized clinical trials that compared composite resin restorations placed with self-etch and etch-and-rinse in NCCLs were included. After removal of duplicates and non-eligible articles, 50 articles from 42 studies (follow-ups of the same study were merged) remained for synthesis of the risk of bias (Cochrane Risk of bias tool).

RESULTS

Thirteen studies were at "high" risk of bias, yielding 29 studies for meta-analysis. No difference on the POS after restoration placement (risk ratio [RR] 1.04; 95% CI 0.81 to 1.34) as well as in the retention rates for all follow-up periods was observed. The etch-and-rinse approach produced less marginal discoloration at 18 months to 2 years (RR 1.51; 95% CI 1.21 to 1.90) and at 4 to 5 years (RR 1.81; 95% CI 1.28 to 2.55) (p<0.0007).

CONCLUSIONS

The adhesive strategy did not influence the POS and the retention rates of composite resin in NCCLs in any of the follow-up periods; but less marginal discoloration was found in etch-and-rinse adhesives.

CLINICAL SIGNIFICANCE

Composite resin restorations placed with self-etch and etch-and-rinse adhesives produce restoration with the similar clinical service and POS, however using etch-and-rinse adhesives one can reduce marginal discoloration. PROSPERO registration number: CRD42015019533.

Stress-strain Analysis of Premolars With Non-carious Cervical Lesions: Influence of Restorative Material, Loading Direction and Mechanical Fatigue

Noncarious cervical lesions (NCCLs) are characterized by a loss of dental structure at the cementoenamel junction (CEJ) caused by stress, biocorrosion, and attrition. Variations in occlusal loading can promote different stress and strain patterns on the CEJ. Restoration of NCCLs is part of lesion management; however, there is still no conclusive restorative protocol for NCCLs. This study aimed to evaluate the stress and strain distribution of maxillary premolars with NCCLs according to three factors: 1) restorative technique; 2) direction of occlusal loading; and 3) mechanical fatigue. Three-dimensional (3D) finite element analysis (FEA) and strain gauge testing were used to assess stress and strain, respectively. 3D-FEA orthotropic, linear, and elastic models were generated: sound tooth (SO); unrestored NCCL; or NCCL restored with glass ionomer; flowable composite resin; nanofilled composite resin (CR); lithium disilicate ceramic; and nanofilled composite resin core associated with a lithium disilicate laminate (CL). A 150-N compressive static load was applied in two conditions: axially in both cusps (Al); and at a 45° angle to the long axis of the tooth applied to the palatine cusp (Ol). For the experimental tests, specimens were treated as described previously, and one strain gauge was attached to the buccal surface of each tooth to record tooth strains before and after cyclic loading (200,000 cycles, 50 N). FEA showed that the association of NCCL and Ol resulted in higher stress values. CR and CL restorations showed the closest biomechanical behavior to SO for both loading types. Loaded Al or Ol specimens showed higher strain values after mechanical fatigue. Lower stress and strain were observed with Al when compared with Ol. The restoration of NCCLs with composite resin only or associated with ceramic laminates seems to be the best approach because the results for those groups were similar in biomechanical behaviors to sound teeth.

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 evaluation of self-etch and total-etch adhesive systems in noncarious cervical lesions: a two-year report

OBJECTIVE

The purpose of this study was to compare the clinical performance of two self-etch dental adhesives with Single Bond Plus, a traditional one-bottle total-etch dental adhesive, for the restoration of noncarious cervical lesions.

MATERIALS AND METHODS

A total of 156 restorations were placed in noncarious cervical lesions with a minimum depth of 1.5 mm. Patients had no chronic periodontal disease and had normal salivary function. Each patient received restorations on three teeth, each bonded with either Adper Single Bond Plus, Adper Easy Bond, or Adper Scotchbond SE dental adhesive. All lesions were restored with Filtek Supreme Plus composite resin. All teeth were isolated with a rubber dam, received a short enamel bevel, and were cleaned with flour of pumice. The adhesives and resin composite were applied following the manufacturers' instructions. Restorations were clinically evaluated at baseline, six months, one year, and two years using modified US Public Health Service criteria.

RESULTS

Two-year retention was recorded as 97.3%, 90.5%, and 95.2%, for Single Bond Plus, Scotchbond SE, and Easy Bond, respectively. Statistical analysis did not show a significant difference (p>0.05) in clinical performance between any of the three adhesives after a period of two years.

Influence of etching ability of one-step self-etch adhesives on bonding to sound and non-carious cervical sclerotic dentin

The purpose of this study was to evaluate influence of etching ability of one-step self-etch adhesives on bonding to non-carious cervical sclerotic lesion. Forty-eight human maxillary premolars with and without natural non-carious cervical sclerotic lesions at buccal surfaces were used in this study. Artificial wedge-shaped lesions were prepared in sound premolars. All lesions were bonded with Bond Force (BF; pH=2.3) or G-Bond Plus (GBA; pH=1.5) according to the manufacturers' instructions. After water storage for 24 hours at 37°C, bonded specimens were subjected to microtensile bond test to measure bond strength to the gingival wall in each lesion. The μTBS of BF to the natural lesion was significantly lower than that of artificial lesion (p<0.05), while for GBA, there is no significant difference (p>0.05). There was no difference in μTBS to artificial lesion between these two adhesives, however in case of non-carious cervical sclerotic lesion, the μTBS of GBA was statistically higher than that of BF.

The Influence of a Short Training Program on the Clinical Examination of Dental Restorations

Training in restoration assessment and the evaluation of such in the clinical environment is shown to produce positive benefits that include improved reliability and agreement with the set standard.

Correlation between microtensile bond strength data and clinical outcome of Class V restorations

OBJECTIVE

To determine if the results of resin-dentin microtensile bond strength (μTBS) is correlated with the outcome parameters of clinical studies on non-retentive Class V restorations.

METHODS

Resin-dentin μTBS data were obtained from one test center; the in vitro tests were all performed by the same operator. The μTBS testing was performed 8 h after bonding and after 6 months of storing the specimens in water. Pre-test failures (PTFs) of specimens were included in the analysis, attributing them a value of 1MPa. Prospective clinical studies on cervical restorations (Class V) with an observation period of at least 18 months were searched in the literature. The clinical outcome variables were retention loss, marginal discoloration and marginal integrity. Furthermore, an index was formulated to be better able to compare the laboratory and clinical results. Estimates of adhesive effects in a linear mixed model were used to summarize the clinical performance of each adhesive between 12 and 36 months. Spearman correlations between these clinical performances and the μTBS values were calculated subsequently.

RESULTS

Thirty-six clinical studies with 15 adhesive/restorative systems for which μTBS data were also available were included in the statistical analysis. In general 3-step and 2-step etch-and-rinse systems showed higher bond strength values than the 2-step/3-step self-etching systems, which, however, produced higher values than the 1-step self-etching and the resin modified glass ionomer systems. Prolonged water storage of specimens resulted in a significant decrease of the mean bond strength values in 5 adhesive systems (Wilcoxon, p<0.05). There was a significant correlation between μTBS values both after 8 h and 6 months of storage and marginal discoloration (r=0.54 and r=0.67, respectively). However, the same correlation was not found between μTBS values and the retention rate, clinical index or marginal integrity.

SIGNIFICANCE

As μTBS data of adhesive systems, especially after water storage for 6 months, showed a good correlation with marginal discoloration in short-term clinical Class V restorations, longitudinal clinical trials should explore whether early marginal staining is predictive for future retention loss in non-carious cervical restorations.