Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 02 Feb 2020

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

,
,
,
,
,
,
,
, and
Page Range: E34 – E59
DOI: 10.2341/19-252-L
Save
Download PDF

Clinical Relevance

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

SUMMARY

Objective:

The aim of this meta-analysis was to investigate the clinical performance of filled vs unfilled adhesive systems when applied in noncarious cervical lesions.

Methods and Materials:

A systematic search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and SIGLE. Gray literature was also screened. Only randomized controlled clinical trials were included. The risk of bias of the studies was evaluated using the Cochrane Collaboration’s tool. A random-effects meta-analysis was conducted to compare the retention rate, marginal discoloration, and secondary caries of noncarious cervical lesions restored with filled adhesives vs unfilled adhesives. The quality of the body of evidence was assessed using the GRADE approach.

Results:

A total of 3662 studies were identified after removal of duplicates. Twenty-nine studies remained for qualitative analyses and 28 studies for the meta-analysis. Only one study was judged to have a low risk of bias, and the other 28 were considered to have unclear risk of bias. There was no statistically significant difference between filled adhesives compared with unfilled adhesives in relation to loss of retention, marginal discoloration, or secondary caries at any of the follow-up periods (12–18 months, 24–30 months, 3 years, and 5 years or longer). The quality of evidence was graded as moderate for most outcomes at the respective follow-ups, except when there was an explained heterogeneity, which occurred mainly for loss of retention at the 12-month to 3-year follow-up. The results did not depend on whether microfilled or nanofilled adhesives had been investigated.

Conclusions:

The addition of fillers into the composition of adhesive systems did not increase the clinical performance (retention rates, marginal discoloration, or secondary caries) of composite restorations placed in noncarious cervical lesions when compared with unfilled adhesives.

INTRODUCTION

In recent decades, because of an increasing demand for esthetic restorations, composite resins have gained a prominent role in modern restorative dentistry. Nowadays, composite resins are the most widely used dental material, representing 65% of the restorations currently placed in the United States.1,2 However, it is worth mentioning that 50% to 70% of newly placed restorations are the result of failure of preexisting restorations, which results in millions of dental care dollars spent annually on replacement of these restorations.2–4 Many of those replacements, however, are unnecessary as either the defects that led to the replacement of the restoration could be repaired adhesively with composite resins or the restorations are replaced due to economic reasons or false diagnosis by the dentist (eg, confusion of discolored margin with caries at the margins).5–7

Among several clinical problems of esthetic restorations, the bonding interface between the dentin and the direct restorative material is considered one of the Achilles’ heels of esthetic restorations. Recently published reviews have reported that although an improvement in the clinical performance of adhesive restorations has been observed, the retention rates of composite restorations placed in noncarious cervical lesions are still a clinical problem.8,9

Although the exact mechanism responsible for bond degradation is not completely understood,2 one contributing factor for debonding may arise from the low mechanical properties of the adhesive layer that bonds the composite resin material to the dental substrate. Indeed, among the substrates of this bonded interface, the adhesive layer has the lowest elastic modulus.10,11 When submitted to masticatory stresses, the adhesive layer suffers the greatest level of strain among the components. Stress that exceeds the inherent strength of the adhesive layer results in defects, cracks, or abrupt catastrophic failure of the resin-dentin bond.12,13

Adhesive systems traditionally do not contain filler particles.14 However, from a theoretical perspective and by analogy with resin composites, the addition of fillers increases the mechanical properties of the adhesive layer.15,16 This concept was called the elastic cavity wall concept.17,18 In the past, manufacturers added varying proportions of glass filler particles (microfiller 1–5 μm) in the hydrophobic bonding bottle of three-step etch-and-rinse adhesives.16,19,20 These filled adhesives were loaded up to 40–50 wt%,19 for example, of Optibond FL (Kerr Co, Orange, CA, USA) and PermaQuick (Ultradent, South Jordan, UT, USA). Because of the very good clinical performance in long-term clinical trials of these highly filled adhesives,21–24 the same strategy was used in simplified versions of two-step etch-and-rinse adhesives and in the self-etch adhesives.8

In simplified adhesives, hydrophobic resins are combined with priming and/or acidic monomers, which do not allow the addition of a large filler amount. For example, two-step etch-and-rinse adhesives contain about 8.5–15 wt% of fillers in their composition (OptiBond Solo, Kerr Co.; One-Step Plus, Bisco Inc, Schaumburg, IL, USA),16,25–27 which is less than half of the amount that is added in three-step etch-and-rinse systems. By adding large filler amounts, adhesives become more viscous, and this jeopardizes the wettability of the dental substrates.15,16

Instead of microfillers, nanofillers have been added into the adhesive systems.28 Apart from improving the strength of the adhesive layers, nanofillers can penetrate into dentin tubules and into the collagen network.16,27 Nanometer-sized silica (pure silicon dioxide) smaller than 20 nm are usually added.26,29 Some two-step etch-and-rinse systems (Prime & Bond NT and XP Bond, Dentsply Sirona and Adper Scotchbond 2 XT, 3M OralCare) and one-step self-etch adhesive systems (Clearfil S3 Bond, Kuraray and G-Bond, GC Corp) that contain nanofillers are available on the market; the amount usually ranges between 5 wt% and 10 wt%.16

Studies have shown that simplified adhesives with nanofillers may have better mechanical properties compared with unfilled adhesive systems; however, the improvement is material dependent.30,31 In addition, studies have also proven that the addition of nanofillers does not increase the bond strength to dentin.32–35 A closer view showed inconclusive results when clinical studies evaluating filled vs unfilled adhesives were evaluated.36–45 Therefore, the aim of this systematic review and meta-analysis was to answer the following focused PICO question-(P, participant; I, intervention; C, comparator; O, outcome): “Are the retention rates, marginal discoloration, and secondary caries of composite resin restorations placed in noncarious cervical lesions of patients superior when bonded with filled/nanofilled adhesives compared with unfilled adhesives?”

METHODS AND MATERIALS

The methodology described in the present study follows the PRISMA requirements (Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement).46

Protocol and Registration

The study was registered in the PROSPERO database (CRD42018093198) and performed from May to August 2018 at the State University of Ponta Grossa, Paraná, Brazil.

Information Sources and Search Strategy

The search strategy used in the PubMed database was developed based on the concepts of patient and intervention from the focused PICO question described at the end of the Introduction section. Within each concept, the controlled vocabulary (Medical Subject Headings terms) and free keywords were combined with the Boolean operator “OR.” Then, the concepts were combined with the Boolean operator “AND” to restrict the search. A filter for randomized clinical trials was also used for the PubMed database (Table 1). Table 1 also lists other electronic databases that were searched (Web of Science, Scopus, Cochrane Library, Latin American and Caribbean Health Sciences Literature database [LILACS] and Brazilian Library in Dentistry [BBO]). The reference lists of all primary studies were hand searched for additional relevant publications as well as links to related articles of each primary study in the PubMed database. No restrictions on publication date or languages were made.

Table 1: Electronic Database and Search Strategy
Table 1:
Table 1: Electronic Database and Search Strategy (cont.)
Table 1:
Table 1: Electronic Database and Search Strategy (cont.)
Table 1:

The gray literature was also inspected by looking up abstracts of the International Association for Dental Research and their regional divisions (1990–2016), the System for Information on Grey literature in Europe (SIGLE), dissertations and theses using the ProQuest Dissertations and Theses full-text database, as well as the Periodicos Capes Theses database. Ongoing trials were searched in the following clinical trials registries: Current Controlled Trials (www.controlled-trials.com), International Clinical trials registry platform (http://apps.who.int/trialsearch/), ClinicalTrials.gov (www.clinicaltrials.gov), Rebec (www.rebec.gov.br), and EU Clinical Trials Register (https://www.clinicaltrialsregister.eu).

Eligibility Criteria

We included randomized clinical trials (RCTs) with parallel and split-mouth designs that compared the retention rates or other secondary outcomes (caries at restorative margins and marginal discoloration) of filled/nanofilled adhesives vs unfilled adhesives for bonding composite resin restorations in noncarious cervical lesions. RCTs were excluded if they 1) compared the same type of adhesive, 2) compared the association among different adhesives in the same restorations, or 3) compared filled vs nanofilled adhesives.

Study Selection and Data Collection Process

After database screening, duplicates were removed and possible eligible articles were selected according to title and abstracts. Full-text articles were obtained by two authors (JLG and BMM), and they were classified according to the inclusion criteria. Pilot-tested, customized extraction forms were used to register details about the studies, such as study design, participants, interventions, and outcomes. Each study received an identification number (study ID), combining the first author name and the publication year. Authors were not contacted for further information to avoid recall bias.

Data Items

When there were multiple reports of the same study (ie, reports with different follow-ups), data from all reports were extracted directly into a single data collection form to avoid overlapping data. We collected data about retention rates, marginal discoloration, and secondary caries. Usually, clinical studies on restorative materials use USPHS criteria, which are classified as Alpha, Bravo, and Charlie. We dichotomized the ordinal data into Alpha+Bravo/Charlie. For clinical studies using World Dental Federation criteria, the ordinal data were dichotomized as clinically acceptable or clinically unacceptable. The data were collected into different follow-up evaluations: 12 to 18 months, 24 to 30 months, 3 years, and 5 years or longer. When more than one adhesive of each type was included in the study, their values were combined to make a single entry. In the case of data inconsistencies between reports of different follow-up evaluations of the same study, data were collected from the most recent article. Subgroup analysis based on the type of filler (regular or nanofillers) was performed whenever data were available.

Risk of Bias in Individual Studies

Two authors (JLG and BMM) independently assessed the risk of bias of the studies selected using the Cochrane Collaboration’s tool for assessing risk of bias in randomized trials.47 The risk of bias tool contains six domains: sequence generation, allocation concealment, blinding of the outcome assessors, incomplete outcome data, selective outcome reporting, and other possible sources of bias. Each domain was judged to be at low, unclear, or high risk of bias according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0 (http://handbook.cochrane.org).

The key domains of this study were sequence generation, allocation concealment, and examiner blinding. At the study level, the study was at low risk of bias if all key domains were at low risk of bias. If one key domain was judged as having high risk of bias, the study was considered as having a high risk of bias. If at least one key domain was judged as at unclear risk among other low-risk of bias domains, the study was considered as having unclear risk of bias. During data selection and quality assessment, any disagreements between the reviewers were solved through discussion and if needed by consulting a third reviewer (ADL).

Summary Measures and Synthesis of the Results

Dichotomous data (loss of retention, marginal discoloration, and secondary caries) were meta-analyzed to obtain a combined estimate of the overall risk difference (RD) with a 95% confidence interval. This procedure was done in different follow-ups: 12 to 18 months, 24 to 30 months, 3 years, and 5 years or longer. Subgroup analysis based on the type of filler (microfillers or nanofillers) was performed whenever data were available in each follow-up. Random effect models were used for all meta-analyses, and we assessed heterogeneity (which represents any kind of variability among studies) by using the Cochran Q test and I2 statistics. We carried out the analyses by using the software RevMan 5.3 (Review Manager version 5, The Cochrane Collaboration, Copenhagen, Denmark). In case of heterogeneity, a sensitivity analysis was performed.

Assessment of the Quality of Evidence Using GRADE

The quality of the evidence was graded for each outcome variable across studies (body of evidence) using the Grading of Recommendations: Assessment, Development and Evaluation (GRADE; http://www.gradeworkinggroup.org/) to determine the overall strength of evidence. The GRADE approach is used to contextualize or justify intervention recommendations with four levels of evidence quality, ranging from high to very low.

The GRADE approach begins with the study design (RCTs or observational studies) and then addresses five reasons (risk of bias, imprecision, inconsistency, indirectness of evidence, and publication bias) to possibly rate down the quality of evidence (one or two levels) and three to possibly rate up the quality (large effect, management of confounding factors, dose-response gradient).48 Each one of these topics was assessed as “no limitation,” “serious limitations,” or “very serious limitations” to allow categorization of the quality of the evidence for each outcome into high, moderate, low, and very low. The “high-quality” level suggests that we are very confident that the true effect lies close to the estimate of the effect. On the other extreme, a study of “very low quality” suggests that we have very little confidence in the effect estimate and the estimate reported can be substantially different from what was measured.

RESULTS

Characteristics of Included Studies

After the database screening and removal of duplicates, 3662 articles were identified (Figure 1). After title screening, 363 articles remained, and this number was reduced to 75 articles after careful examination of the abstracts (Figure 1). Among these articles, 41 were excluded for the following reasons: 1) the studies compared the same type of adhesive system (n=19),40,49–66 2) the studies used the same type of adhesive system in both study groups (n=18),67–84 and 3) the studies compared filled vs nanofilled adhesive systems (n=4).85–88

Figure 1.Figure 1.Figure 1.
Figure 1. Flowchart diagram showing the number of articles obtained in the different phases of the study.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

A total of 32 articles remained for qualitative evaluation. From these 32 articles, 3 articles38,89,90 reported longer follow-ups of earlier studies. Therefore, there were 29 studies among 32 publications. Tables 2, 3, and 4 characterize the 29 included studies. The follow-up time of the studies varied from 12 months91–93 to 8 years.90 All studies placed multiple restorations per patient. In this design, any patient could receive as many restorations as possible, depending on the number of available noncarious cervical lesions.

Table 2: Summary of the Studies Included in the Systematic Review
Table 2:
Table 2: Summary of the Studies Included in the Systematic Review (ext.)
Table 2:
Table 2: Summary of the Studies Included in the Systematic Review (cont.)
Table 2:
Table 2: Summary of the Studies Included in the Systematic Review (ext.)
Table 2:
Table 3: Summary of the Studies Included in the Systematic Review: Part 2
Table 3:
Table 3: Summary of the Studies Included in the Systematic Review: Part 2 (ext.)
Table 3:
Table 3: Summary of the Studies Included in the Systematic Review: Part 2 (Cont.)
Table 3:
Table 3: Summary of the Studies Included in the Systematic Review: Part 2 (Cont.)
Table 3:
Table 4: Summary of Findings a
Table 4:

The mean age of the participants was approximately 50 (±7) years.a Most of the studies (n=17, 59%) used cotton rolls and a saliva ejector to prevent contamination during the restorative protocol,b while 8 studies used a rubber dam.89,92,98,100,105–108

In few studies (n=6), the enamel was beveled.38,94,99,102,107,108 Different types of adhesive systems were used in the studies, varying from three-step etch-and-rinse adhesives (n=11)c to one-step self-etch adhesives (n=14).d The number of restorations per adhesive system used in the studies evaluated varied from 14 restorations93 to 189 restorations.107

The wet bonding technique was applied in 18 studies.e Some studies (n=8) mentioned that the application of the adhesive system was done while the adhesive was actively moved on the surface (agitation).f The time to evaporate the solvent was 5 seconds in most studies (n=14).g Adhesives were composed of different solvents such as water, ethanol, acetone, and tert-butanol. Most of the studies did not report on the operator experience (graduate, postgraduate, academic dentist, general practitioner), but for those for which this information was reported, most of the operators were academic dentists.89,90,95,99,102,105–108 Only one study reported that the operator was a graduate student.103 No study was conducted with general practitioners.

Meta-analysis

A meta-analysis was performed that included all studies with exception of one,98 which was considered at high risk of bias in the key domain examiner blinding. The risk of bias assessment is provided in Figure 2. Some follow-ups could not be integrated into the meta-analysis because of lack of information. If data were not available or could not be extracted, the study was not considered for the meta-analysis. No difference was observed between the subgroup analysis in any of the meta-analyses that had been conducted.

Figure 2.Figure 2.Figure 2.
Figure 2. Summary of the risk of bias assessment for the 27 studies included in the meta-analysis according to the Cochrane Collaboration tool. The risk of bias tool contains six domains: sequence generation, allocation concealment, blinding of the outcome assessors, incomplete outcome data, selective outcome reporting, and other possible sources of bias. Each domain was judged to be at low, unclear, or high risk of bias according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Loss of Retention—This analysis was based on 27 studies.h In the overall analysis, which took into consideration both subgroups (filled vs unfilled and nanofilled vs unfilled), no significant difference between the two groups was detected in the follow-ups of 12 to 18 months (RD=−0.01; 95% confidence interval [CI], −0.03 to 0.02; p=0.60; Figure 3), 24 to 30 months (RD=0.00; 95% CI, −0.03 to 0.03; p=0.95; Figure 3), 3 years (RD=−0.04; 95% CI, −0.10 to 0.03; p=0.26; Figure 4), and 5 or more years (RD=−0.01; 95% CI, −0.10 to 0.07; p=0.77; Figure 4). Analysis of heterogeneity revealed that data were heterogeneous at 12 to 18 months, 24 to 30 months, and 3-year follow-ups (p<0.03; I2>45%; Figures 3 and 4) but not at the 5-year recall (p=0.28; I2=21%; Figure 4).

Figure 3.Figure 3.Figure 3.
Figure 3. Forest plot of restorations that suffered retention loss comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Figure 4.Figure 4.Figure 4.
Figure 4. Forest plot of restorations that suffered retention loss comparing filled vs unfilled adhesives at 3 and 5 or more years.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Marginal Discoloration—This analysis was based on 22 studies.i In the overall analysis, which took into consideration both subgroups, no significant difference between the two groups was detected in the follow-ups of 12 to 18 months (RD=−0.02; 95% CI, −0.04 to 0.00; p=0.07; Figure 5), 24 to 30 months (RD=−0.04; 95% CI, −0.10 to 0.02; p=0.18; Figure 5), or 3 years (RD=0.01; 95% CI, −0.06 to 0.09; p=0.75; Figure 5). Analysis of heterogeneity revealed that data were heterogeneous at 12 to 18 months (p=0.16; I2=22%; Figure 5), and 3-year follow-up (p=0.84; I2=0%; Figure 6) but not at the 24 to 30 months recall (p,0.0002; I2=69%; Figure 5).

Figure 5.Figure 5.Figure 5.
Figure 5. Forest plot of restorations with marginal discoloration comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Figure 6.Figure 6.Figure 6.
Figure 6. Forest plot of restorations with marginal discoloration comparing filled vs unfilled adhesives at 3 years.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Secondary Caries—This analysis was based on 17 studies.j In the overall analysis, which took into consideration both subgroups, no significant difference between groups was detected in the follow-ups of 12 to 18 months (RD=−0.00; 95% CI, −0.01 to 0.01; p=0.88; Figure 7), 24 to 30 months (RD=−0.00; 95% CI, −0.02 to 0.01; p=0.59; Figure 7), or 3 years (RD=−0.02; 95% CI, −0.06 to 0.01; p=0.16; Figure 8). Analysis of heterogeneity revealed that data were not heterogeneous at any given recall time (p>0.32; I2<13%; Figures 7 and 8).

Figure 7.Figure 7.Figure 7.
Figure 7. Forest plot of restorations with secondary caries comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Figure 8.Figure 8.Figure 8.
Figure 8. Forest plot of restorations with secondary caries comparing filled vs unfilled adhesives at 3 years.

Citation: Operative Dentistry 46, 1; 10.2341/19-252-L

Assessment of the Quality of Evidence—In the summary of findings in Table 4, we can observe that for the outcome variable loss of retention, most of the follow-ups were graded as having a low quality of evidence, except for 5 or more year recalls, which were graded as moderate. Unclear risk of bias and unexplained heterogeneity were the reasons for downgrading the level of evidence. For the outcome variable marginal discoloration, the 12- to 18-month recall and the 3-year recall were graded as moderate (unclear risk of bias of the eligible studies) and the 24- to 30-month recall was graded as having a low quality of evidence (unclear risk of bias and unexplained heterogeneity). All meta-analyses of the outcome variable secondary caries were graded as moderate because of the unclear risk of bias of the studies.

DISCUSSION

Systematic reviews and meta-analyses are important for resolving controversies between clinical trials and to provide clinical input for guidelines that address adequate clinical care delivered by oral health personnel, especially general practitioners.110 According to the results of the present study, the addition of fillers or nanofillers in adhesive systems does not significantly improve the clinical performance of the retention rate, marginal discoloration, or secondary caries.

When the first filled adhesive systems emerged in the market, the theoretical concept was that filled adhesive systems act as thickening agents within the adhesive layer. The formation of a thick layer of adhesive interface will improve the mechanical properties, and15,16 according to the so-called elastic bonding concept,17,18 the adhesive layer should absorb the compression produced by the tooth-flexure stress, thus reducing interfacial stresses and preserving the marginal integrity,17,18,111 which eventually should result in better retention rate of the adhesively bonded restorations.12,13

There are, however, options to increase the thickness of the adhesive layer: first, to apply two layers of adhesive, and second, to use a separate hydrophobic layer such as the three-step etch-and-rinse or two-step self-etch adhesive systems.8,112 Some systematic reviews came to the conclusion that simplified adhesive systems such as the one-step self-etch systems reduce the retention rates and increase marginal discoloration of Class V composite resin restorations.8,113 However, a closer view of the RCTs of the present study showed that although 16 studies evaluated filled vs unfilled adhesives, only a few compared a filled or unfilled adhesive within the same adhesive system group.k This prevented us from investigating this variable by a subgroup analysis or meta-regression.

It is worthwhile to mention that flowable composites are also used with the goal of absorbing occlusal stress (“elastic bonding concept”).17,18 However, several systematic reviews have shown that the use of flowable resin composite compared with high-viscous resin composites did not affect the retention rate or marginal discoloration of Class V restorations.8,113,116 Microfillers in adhesive systems (1–5 μm) do not penetrate into the interfibrillar spaces but are observed within the adhesive layer.117 Therefore, there are adhesive systems with glass particles of 20-nm size or lower (pure silicon dioxide, from either colloidal or pyrogenic origin).26,29 According to the manufacturers, the nanofillers are small enough to penetrate into dentin tubules and infiltrate the interfibrillar spaces of demineralized dentin. Furthermore, it was suggested that infiltration of the interfibrillar channels could provide a strengthening element for demineralized dentin.16,27

However, the nanofillers must be physically and chemically stabilized to prevent them from aggregating during storage and/or during the application of the adhesive, which makes these “filler clusters” too large to infiltrate the interfibrillar spaces.27,118 However, several studies showed that no nanofiller had been found inside the hybrid layer or the demineralized dentin.27,119,120 Furthermore, it has been reported that exposed collagen may function as a filter121 that does not allow the nanofillers to penetrate. The molecular weight of the nanofillers and the resin monomers of the adhesives differ substantially. Therefore, the diffusion rate is very different, which inhibits the complete infiltration of the nanofillers into the interfibrillar space.27,122 Some authors claim that in demineralizing dentin, there is a formation of a hydrogel of residual substance, proteoglycans, and noncollagenous proteins that may physically impede the infiltration of nanofillers.123

Also due to the natural tendency to aggregate, micrometric electrodense filler clusters will form that are larger than the interfibrillar spaces.16,27 Osorio and others119 showed that in self-etch adhesive systems, large clusters were observed that were beyond the dimensions of the interfibrillar spaces of the collagen fibers. Some authors suggested that if the volume of the nanofillers within the adhesive was lower than 3.0 wt%, they did not aggregate that easily and would increase the bond strength to dentin.124 However, in commercial simplified etch-and-rinse and self-etch adhesives, more than 5 wt% is found.16 On the other hand, the lower amount of nanofillers did not significantly improve the mechanical properties of the adhesive layer.20,30,31 Other researchers used specific techniques to produce nonaggregated nanoparticles with high antimicrobial potential.125,126 These facts may also explain why no significant increase in the bond strength to dentin could be observed when nanofilled-containing simplified adhesives had been tested compared with unfilled simplified adhesives.32–35

The results of the present study should be interpreted with caution because they represent an overall comparison without taking into consideration specific variations in the products (monomer and solvent composition, application technique, evaporation solvent time, and moisture control). However, if one of these factors has an important role in the clinical performance of an adhesive, merging studies in a meta-analysis will increase the power to detect the role of such a variable. This would not be possible in primary studies with low sample sizes.

Also, the inadequate randomization of some clinical studies may have led to the fact that the chances of a patient being allocated to the test or control group were not the same for all patients, and known and unknown prognostic factors had not been balanced out among the groups.47,110,127 The random sequence should be protected until implementation127 (allocation concealment). Most of the eligible studies that had been included in this systematic review were classified as having unclear risk of bias. This judgment was based on the lack of clear description of the randomization and allocation concealment process. This is in accordance with what was recently published by Reis and others in 2018,128 who reported that more than 60% of RCTs about adhesive systems that had been tested in noncarious cervical lesions had a high or unclear risk of bias for randomization and allocation concealment.

Therefore, long-term and well-conducted RCTs that comply with the requirements of an RCT are needed to evaluate possible technological improvements of adhesive systems such as the addition of nanofillers to improve the longevity of the bonding interface to dentin.

CONCLUSIONS

The addition of micro or nanofillers to the composition of adhesive systems did not increase the clinical performance (retention rates, marginal discoloration, or secondary caries) in noncarious cervical lesions compared with unfilled adhesive systems.

Acknowledgements

This study was part of the presentation by Prof Dr Alessandro D Loguercio during the Annual Meeting of the World Dental Federation, Buenos Aires, Argentina (2018) at the Symposium “Nanoparticles in Dentistry: Risks and Promises,” together with Prof Dr Alexander Besinis and Prof Gottfried Schmalz and coordinated by Prof Dr Reinhard Hickel. This study was partially supported by the National Council for Scientific and Technological Development (CNPq) under grants 303332/2017-4 and 304105/2013-9 and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001.

    Conflict of Interest The authors of this article certify that they have no proprietary, financial, or other personal interest of any nature or kind in any product, service, and/or company that is presented in this article.

REFERENCES

  • 1.
    Christensen GJ ( 2010) Should resin-based composite dominate restorative dentistry today?Journal of the American Dental Association141(
    12
    ) 1490– 1493.
  • 2.
    Spencer P, Jonggu Park QY, Misra A, Bohaty BS, Singh V, Parthasarathy R, Sene F, de Paiva Goncalves SE, & LaurenceJ( 2012) Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target?Brazilian Dental Science15(
    1
    ) 4– 18.
  • 3.
    Jokstad A, Bayne S, Blunck U, Tyas M, & WilsonN( 2001) Quality of dental restorations. FDI Commission Project 2-95International Dentistry Journal51(
    3
    ) 117– 158.
  • 4.
    Beazoglou T, Eklund S, Heffley D, Meiers J, Brown LJ, & BailitH( 2007) Economic impact of regulating the use of amalgam restorationsPublic Health Reports122(
    5
    ) 657– 663.
  • 5.
    Estay J, Martin J, Viera V, Valdivieso J, Bersezio C, Vildosola P, Mjor IA, Andrade MF, Moraes RR, Moncada G, Gordan VV, & FernandezE( 2018) 12 years of repair of amalgam and composite resins: a clinical studyOperative Dentistry43(
    1
    ) 12– 21. doi:10.2341/16-313-c
  • 6.
    Mjor IA ( 2005) Clinical diagnosis of recurrent cariesJournal of the American Dental Association136(
    10
    ) 1426– 1433.
  • 7.
    Signori C, Gimenez T, Mendes FM, Huysmans M, Opdam NJM, & CenciMS( 2018) Clinical relevance of studies on the visual and radiographic methods for detecting secondary caries lesions: a systematic reviewJournal of Dentistry7522– 33.
  • 8.
    Peumans M, De Munck J, Mine A, & Van MeerbeekB( 2014) Clinical effectiveness of contemporary adhesives for the restoration of non-carious cervical lesions: A systematic reviewDental Materials30(
    10
    ) 1089– 1103.
  • 9.
    Schroeder M, Correa IC, Bauer J, Loguercio AD, & ReisA( 2017) Influence of adhesive strategy on clinical parameters in cervical restorations: A systematic review and meta-analysisJournal of Dentistry6236– 53.
  • 10.
    Van Meerbeek BWG, Celis JP, Roos JR, Braem M, Lamberchts P, & VanherleG( 1993) Assessment by nano-indentation ofthe hardness and elasticity of the resin-dentin bonding area.Journal of Dental Researsh721434– 1442.
  • 11.
    Sano H, Takatsu T, Ciucchi B, Russell CM, & PashleyDH( 1995) Tensile properties of resin-infiltrated demineralized human dentinJourl of Dental Research74(
    4
    ) 1093– 1102.
  • 12.
    Braga RR, Ballester RY, & FerracaneJL( 2005) Factors involved in the development of polymerization shrinkage stress in resin-composites: a systematic reviewDental Materials21(
    10
    ) 962– 970.
  • 13.
    Ferracane JL & HiltonTJ( 2016) Polymerization stress—is it clinically meaningful?Dental Materials32(
    1
    ) 1– 10.
  • 14.
    Frankenberger RLM, Perdigao J, Ambrose WW, & RosaBT( 2002) The use of flowable composites as filled adhesives.Dental Materials Journal18(
    3
    ) 227– 238.
  • 15.
    Moszner N, Salz U, & ZimmermannJ( 2005) Chemical aspects of self-etching enamel-dentin adhesives: a systematic reviewDental Materials21(
    10
    ) 895– 910.
  • 16.
    Van Landuyt KL, Snauwaert J, De Munck J, Peumans M, Yoshida Y, Poitevin A, Coutinho E, Suzuki K, Lambrechts P, & Van MeerbeekB( 2007) Systematic review of the chemical composition of contemporary dental adhesivesBiomaterials28(
    26
    ) 3757– 3785.
  • 17.
    Kemp-Scholte CM & DavidsonCL( 1990) Marginal integrity related to bond strength and strain capacity of composite resin restorative systemsJournal of Prosthetetic Dentistry64(
    6
    ) 658– 664.
  • 18.
    Van Meerbeek B, Willems G, Celis JP, Roos JR, Braem M, Lambrechts P, & VanherleG( 1993) Assessment by nano-indentation of the hardness and elasticity of the resin-dentin bonding areaJournal of Dental Research72(
    10
    ) 1434– 1442.
  • 19.
    Perdigao J, Lambrechts P, Van Meerbeek B, Braem M, Yildiz E, Yucel T, & VanherleG( 1996) The interaction of adhesive systems with human dentinAmerican Journal of Dentistry9(
    4
    ) 167– 173.
  • 20.
    Labella R, Lambrechts P, Van Meerbeek B, & VanherleG( 1999) Polymerization shrinkage and elasticity of flowable composites and filled adhesivesDental Materials15(
    2
    ) 128– 137.
  • 21.
    Wilder AD Jr, Swift EJ Jr, Heymann HO, Ritter AV, Sturdevant JR, & BayneSC( 2009) A 12-year clinical evaluation of a three-step dentin adhesive in noncarious cervical lesionsJournal of the American Dental Association140(
    5
    ) 526– 535.
  • 22.
    Peumans M, Wouters L, De Munck J, Van Meerbeek B, & Van LanduytK( 2018) Nine-year clinical performance of a HEMA-free one-step self-etch adhesive in noncarious cervical lesionsJournal of Adhesive Dentistry20(
    3
    ) 195– 203.
  • 23.
    Peumans M, De Munck J, Van Landuyt KL, Poitevin A, Lambrechts P, & Van MeerbeekB( 2012) A 13-year clinical evaluation of two three-step etch-and-rinse adhesives in non-carious Class-V lesionsClinical Oral Investigations16(
    1
    ) 129– 137.
  • 24.
    van Dijken JW ( 2010) A prospective 8-year evaluation of a mild two-step self-etching adhesive and a heavily filled two-step etch-and-rinse system in non-carious cervical lesionsDental Materials26(
    9
    ) 940– 946.
  • 25.
    Tay FR, Pashley DH, Yiu C, Cheong C, Hashimoto M, Itou K, Yoshiyama M, & KingNM( 2004) Nanoleakage types and potential implications: evidence from unfilled and filled adhesives with the same resin compositionAmerican Journal of Dentistry17(
    3
    ) 182– 190.
  • 26.
    Van Meerbeek B, Yoshida Y, Lambrechts P, Vanherle G, Duke ES, Eick JD, & RobinsonSJ( 1998) A TEM study of two water-based adhesive systems bonded to dry and wet dentinJournal of Dental Research77(
    1
    ) 50– 59.
  • 27.
    Tay FR, Moulding KM, & PashleyDH( 1999) Distribution of nanofillers from a simplified-step adhesive in acid-conditioned dentinJournal of Adhesive Dentistry1(
    2
    ) 103– 117.
  • 28.
    Schmalz G, Hickel R, van Landuyt KL, & ReichlFX( 2017) Nanoparticles in dentistryDental Materials33(
    11
    ) 1298– 1314.
  • 29.
    Perdigao J, Lambrechts P, van Meerbeek B, Tome AR, Vanherle G, & LopesAB( 1996) Morphological field emission-SEM study of the effect of six phosphoric acid etching agents on human dentinDental Materials12(
    4
    ) 262– 271.
  • 30.
    Giannini M, Liberti MS, Arrais CA, Reis AF, Mettenburg D, & RueggebergFA( 2012) Influence of filler addition, storage medium and evaluation time on biaxial flexure strength and modulus of adhesive systemsActa Odontologica Scandinavica70(
    6
    ) 478– 484.
  • 31.
    Giannini M, Mettenburg D, Arrais CA, & RueggebergFA( 2011) The effect of filler addition on biaxial flexure strength and modulus of commercial dentin bonding systemsQuintessence International42(
    2
    ) e39– e43.
  • 32.
    Lee YK, Pinzon LM, O’Keefe KL, & PowersJM( 2006) Effect of filler addition on the bonding parameters of dentin bonding adhesives bonded to human dentinAmerican Journal of Dentistry19(
    1
    ) 23– 27.
  • 33.
    Braga RR, Cesar PF, & GonzagaCC( 2000) Tensile bond strength of filled and unfilled adhesives to dentinAmerican Journal of Dentistry13(
    2
    ) 73– 76.
  • 34.
    Nunes MF, Swift EJ, & PerdigaoJ( 2001) Effects of adhesive composition on microtensile bond strength to human dentinAmerican Journal of Dentistry14(
    6
    ) 340– 343.
  • 35.
    Kaaden C, Powers JM, Friedl KH, & SchmalzG( 2002) Bond strength of self-etching adhesives to dental hard tissuesClinical Oral Investigations6(
    3
    ) 155– 160.
  • 36.
    Horsted-Bindslev P, Knudsen J, & BaelumV( 1988) Dentin adhesive materials for restoration of cervical erosions: two- and three-year clinical observationsAmerican Journal of Dentistry1 Spec No 195–199.
  • 37.
    Hansen EK ( 1989) Three-year study of cervical erosions restored with resin and dentin-bonding agentActa Odontologica Scandinavica47(
    5
    ) 301– 306.
  • 38.
    Hansen EK ( 1992) Five-year study of cervical erosions restored with resin and dentin-bonding agentScandinavian Journal of Dental Research100(
    4
    ) 244– 247.
  • 39.
    Dijken J ( 1994) Clinical evaluation of four dentin bonding agents in Class V abrasion lesions: a four-year follow-upDental Materials10(
    5
    ) 319– 324.
  • 40.
    Dijken J ( 2010) A prospective 8-year evaluation of a mild two-step self-etching adhesive and a heavily filled two-step etch-and-rinse system in non-carious cervical lesionsDental Materials26(
    9
    ) 940– 946.
  • 41.
    Dijken J ( 2004) Durability of three simplified adhesive systems in Class V non-carious cervical dentin lesionsAmerican Journal of Dentistry17(
    1
    ) 27– 32.
  • 42.
    Neo J, Chew C, Yap A, & SidhuS( 1996) Clinical evaluation of tooth-colored materials in cervical lesionsAmerican Journal of Dentistry9(
    1
    ) 15– 8.
  • 43.
    Dalkilic EE & OmurluH( 2012) Two-year clinical evaluation of three adhesive systems in non-carious cervical lesionsJournal of Applied Oral Science20(
    2
    ) 192– 199.
  • 44.
    Perdigão J, Dutra-Corrêa M, Saraceni C, Ciaramicoli M, Kiyan V, & QueirozC( 2012) Randomized clinical trial of four adhesion strategies: 18-month resultsOperative Dentistry37(
    1
    ) 3– 11.
  • 45.
    Jang JH, Kim HY, Shin SM, Lee CO, Kim DS, Choi KK, & KimSY( 2017) Clinical effectiveness of different polishing systems and self-etch adhesives in Class V composite resin restorations: two-year randomized controlled clinical trialOperative Dentistry42(
    1
    ) 19– 29.
  • 46.
    Moher D, Liberati A, Tetzlaff J, & AltmanDG( 2009) Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statementBMJ339b2535.
  • 47.
    Higgins JP, Altman DG, Gotzsche PC, Juni P, Moher D, Oxman AD, Savovic J, Schulz KF, Weeks L, & SterneJA( 2011) The Cochrane Collaboration’s tool for assessing risk of bias in randomised trialsBMJ343d5928.
  • 48.
    Guyatt GH, Oxman AD, Schunemann HJ, Tugwell P, & KnottnerusA( 2011) GRADE guidelines: a new series of articles in theJournal of Clinical Epidemiology Journal of Clinical Epidemiology64(
    4
    ) 380– 382.
  • 49.
    Loguercio A, Bittencourt D, Baratieri L, & ReisA( 2007) A 36-month evaluation of self-etch and etch-and-rinse adhesives in noncarious cervical lesionsJournal of the American Dental Association138(
    4
    ) 507– 514.
  • 50.
    Kubo S, Yokota H, Yokota H, & HayashiY( 2009) Two-year clinical evaluation of one-step self-etch systems in non-carious cervical lesionsJournal of Dentistry37(
    2
    ) 149– 155.
  • 51.
    Sartori N, Lopes G, & VieiraL( 2012) Clinical performance of cervical restorations with desensitizing agents: 18-month clinical trialJournal of Adhesive Dentistry14(
    2
    ) 183– 189.
  • 52.
    Browning WD, Blalock JS, Callan RS, Brackett WW, Schull GF, Davenport MB, & BrackettMG( 2007) Postoperative sensitivity: a comparison of two bonding agentsOperative Dentistry32(
    2
    ) 112– 117.
  • 53.
    Zander-Grande C, Ferreira S, Costa T, Loguercio A, & ReisA( 2011) Application of etch-and-rinse adhesives on dry and rewet dentin under rubbing action: a 24-month clinical evaluationJournal of the American Dental Association142(
    7
    ) 828– 835.
  • 54.
    Tsai YL, Nakajima M, Wang CY, Foxton RM, Lin CP, & TagamiJ( 2011) Influence of etching ability of one-step self-etch adhesives on bonding to sound and non-carious cervical sclerotic dentinDental Materials Journal30(
    6
    ) 941– 947.
  • 55.
    Schattenberg A, Werling U, Willershausen B, & ErnstC( 2008) Two-year clinical performance of two one-step self-etching adhesives in the restoration of cervical lesionsClinical Oral Investigations12(
    3
    ) 225– 232.
  • 56.
    Ermis R, Landuyt K, Cardoso M, Munck J, Meerbeek B, & PeumansM( 2012) Clinical effectiveness of a one-step self-etch adhesive in non-carious cervical lesions at 2 yearsClinical Oral Investigations16(
    3
    ) 889– 897.
  • 57.
    Tyas MJ ( 1988) Clinical performance of three dentine bonding agents in Class V abrasion lesions without enamel etchingAustralian Dental Journal33(
    3
    ) 177– 180.
  • 58.
    van Dijken JWV ( 2000) Clinical evaluation of three adhesive systems in Class V non-carious lesionsDental Materials16(
    4
    ) 285– 291.
  • 59.
    Ritter A, Heymann H, Swift E, Sturdevant J, & WilderA( 2008) Clinical evaluation of an all-in-one adhesive in non-carious cervical lesions with different degrees of dentin sclerosisOperative Dentistry33(
    4
    ) 370– 378.
  • 60.
    Kim SY, Lee KW, Seong SR, Lee MA, Lee IB, Son HH, Kim HY, Oh MH, & ChoBH( 2009) Two-year clinical effectiveness of adhesives and retention form on resin composite restorations of non-carious cervical lesionsOperative Dentistry34(
    5
    ) 507– 515.
  • 61.
    Tyas M ( 1996) Clinical evaluation of five adhesive systems: three-year resultsInternational Dental Journal46(
    1
    ) 10– 14.
  • 62.
    Tyas M & ChandlerJ( 1993) One-year clinical evaluation of three dentine bonding agentsAustralian Dental Journal38(
    4
    ) 294– 298.
  • 63.
    Tyas MJ ( 1990) Clinical performance of dentine bonding agents in the enamel-etched Class V abrasion lesionAustralian Dental Journal35(
    5
    ) 459– 462.
  • 64.
    Tyas MJ ( 1992) One-year clinical performance of PMDM-based dentine bonding agentsAustralian Dental Journal37(
    6
    ) 445– 448.
  • 65.
    McCoy R, Anderson M, Lepe X, & JohnsonG( 1998) Clinical success of Class V composite resin restorations without mechanical retentionJournal of the American Dental Association129(
    5
    ) 593– 599.
  • 66.
    Van Meerbeek B, Braem M, Lambrechts P, & VanherleG( 1993) Evaluation of two dentin adhesives in cervical lesionsJournal of Prosthetic Dentistry70(
    4
    ) 308– 314.
  • 67.
    Peumans M, De Munck J, Van Landuyt K, & Van MeerbeekB( 2015) Thirteen-year randomized controlled clinical trial of a two-step self-etch adhesive in noncarious cervical lesionsDental Materials31(
    3
    ) 308– 314.
  • 68.
    Merte K, Frohlich M, Hafer M, Hirsch E, Schneider H, & WinklerM( 2000) Two-year clinical performance of two primer adhesives on Class V restorationsJournal of Biomedical Materials Research53(
    1
    ) 93– 99.
  • 69.
    Abdalla A & SayedH( 2008) Clinical evaluation of a self-etch adhesive in non-carious cervical lesionsAmerican Journal of Dentistry21(
    5
    ) 327– 330.
  • 70.
    Türkün L & CelikE( 2008) Noncarious Class V lesions restored with a polyacid modified resin composite and a nanocomposite: a two-year clinical trialJournal of Adhesive Dentistry10(
    5
    ) 399– 405.
  • 71.
    Sartori N, Stolf SC, Silva SB, Lopes GC, & CarrilhoM( 2013) Influence of chlorhexidine digluconate on the clinical performance of adhesive restorations: a 3-year follow-upJournal of Dentistry41(
    12
    ) 1188– 1195.
  • 72.
    van Dijken JW & PallesenU( 2012) A 7-year randomized prospective study of a one-step self-etching adhesive in non-carious cervical lesions: the effect of curing modes and restorative materialJournal of Dentistry40(
    12
    ) 1060– 1067.
  • 73.
    dall’Orologio GD & LorenzR( 2014) Restorations in abrasion/erosion cervical lesions: 8-year results of a triple blind randomized controlled trialAmerican Journal of Dentistry27(
    5
    ) 245– 250.
  • 74.
    Meerbeek B, Kanumilli P, Munck J, Landuyt K, Lambrechts P, & PeumansM( 2005) A randomized controlled study evaluating the effectiveness of a two-step self-etch adhesive with and without selective phosphoric-acid etching of enamelDental Materials21(
    4
    ) 375– 383.
  • 75.
    Ianzano JA & GwinnettAJ( 1993) Clinical evaluation of Class V restorations using a total etch technique: 1-year resultsAmerican Journal of Dentistry6(
    4
    ) 207– 210.
  • 76.
    Stefanski S & van DijkenJWV( 2012) Clinical performance of a nanofilled resin composite with and without an intermediary layer of flowable composite: a 2-year evaluationClinical Oral Investigations16(
    1
    ) 147– 153.
  • 77.
    Gallo J, Burgess J, Ripps A, Walker R, Ireland E, Mercante D & DavidsonJ( 2005) Three-year clinical evaluation of a compomer and a resin composite as Class V filling materialsOperative Dentistry30(
    3
    ) 275– 281.
  • 78.
    Souza A, Albuquerque N, Mendonca J, Rodrigues L, & SantiagoS( 2016) Randomized Two-year Clinical Evaluation of Oxalic Acid in Restorations of Noncarious Cervical LesionsJournal of Adhesive Dentistry18(
    6
    ) 467– 473.
  • 79.
    Vanherle G, Verschueren M, Lambrechts P, & BraemM( 1986) Clinical investigation of dental adhesive systems. Part I: An in vivo studyJournal of Prosthetic Dentistry55(
    2
    ) 157– 163.
  • 80.
    Tuncer D, Celik C, Yamanel K, & ArhunN( 2017) Clinical evaluation of microhybrid composites in noncarious cervical lesions: 24-month resultsNigerian Journal of Clinical Practice20(
    2
    ) 176– 181.
  • 81.
    Tian F, Wang X, & GaoX( 2014) Clinical evaluation of a two-step etch-and-rinse adhesive and a one-step self-etch adhesive in non-carious cervical lesionBeijing da Xue Xue Bao46(
    1
    ) 58– 61.
  • 82.
    Abdalla AA & Garcia-GodoyF( 2007) Clinical performance of a self-etch adhesive in Class V restorations made with and without acid etchingJournal of Dentistry35(
    7
    ) 558– 563.
  • 83.
    Sugizaki J, Morigami M, Uno S, & YamadaT( 2007) Clinical evaluation and interfacial morphology observation of Xeno III self-etching resin bonding and restorative systemDental Materials Journal26(
    4
    ) 602– 607.
  • 84.
    Torres CRG, Barcellos DC, Batista GR, Pucci CR, Antunes MJS, De La Cruz DB, & BorgesAB( 2014) Five-year clinical performance of the dentine deproteinization technique in non-carious cervical lesionsJournal of Dentistry42(
    7
    ) 816– 823.
  • 85.
    Van Landuyt KL, De Munck J, Ermis RB, Peumans M, & Van MeerbeekB( 2014) Five-year clinical performance of a HEMA-free one-step self-etch adhesive in noncarious cervical lesionsClinical Oral Investigations18(
    4
    ) 1045– 1052.
  • 86.
    Dijken J ( 2013) 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 lesionsDental Materials29(
    11
    ) e271– e280.
  • 87.
    Tuncer D, Yazici A, Özgünaltay G, & DayangacB( 2013) Clinical evaluation of different adhesives used in the restoration of non-carious cervical lesions: 24-month resultsAustralian Dental Journal58(
    1
    ) 94– 100.
  • 88.
    Scotti N, Comba A, Gambino A, Manzon E, Breschi L, Paolino D, Pasqualini D, & BeruttiE( 2016) Influence of operator experience on non-carious cervical lesion restorations: clinical evaluation with different adhesive systemsAmerican Journal of Dentistry29(
    1
    ) 33– 38.
  • 89.
    Perdigão J, Carmo ARP, & GeraldeliS( 2005) Eighteen-month clinical evaluation of two dentin adhesives applied on dry vs moist dentinJournal of Adhesive Dentistry7(
    3
    ) 253– 258.
  • 90.
    Ritter A, Swift E, Heymann H, Sturdevant J, & WilderA( 2009) An eight-year clinical evaluation of filled and unfilled one-bottle dental adhesivesJournal of the American Dental Association140(
    1
    ) 28– 37.
  • 91.
    Araujo JF, Barros TA, Braga EM, Loretto SC, Silva e Souza Pde A & Silva e SouzaMH( 2013) One-year evaluation of a simplified ethanol-wet bonding technique: a randomized clinical trialBrazilian Dental Journal24(
    3
    ) 267– 272.
  • 92.
    Jordan RE & SuzukiM( 1993) Early clinical evaluation of four new bonding resins used for conservative restoration of cervical erosion lesionsJournal of Canadian Dental Association59(
    1
    ) 81– 84.
  • 93.
    Kurokawa H, Miyazaki M, Takamizawa T, Rikuta A, Tsubota K, & UekusaS( 2007) One-year clinical evaluation of five single-step self-etch adhesive systems in non-carious cervical lesionsDental Materials Journal26(
    1
    ) 14– 20.
  • 94.
    Aw T, Lepe X, Johnson G, & ManclL( 2005) A three-year clinical evaluation of two-bottle versus one-bottle dentin adhesivesJournal of the American Dental Association136(
    3
    ) 311– 322.
  • 95.
    Boushell LW, Heymann HO, Ritter AV, Sturdevant JR, Swift EJ, Wilder AD, Chung YR, Lambert CA, & WalterR( 2016) Six-year clinical performance of etch-and-rinse and self-etch adhesivesDental Materials32(
    9
    ) 1065– 1072.
  • 96.
    Burrow M & TyasM( 2007) Clinical evaluation of three adhesive systems for the restoration of non-carious cervical lesionsOperative Dentistry32(
    1
    ) 11– 15.
  • 97.
    Dutra-Correa M, Saraceni C, Ciaramicoli M, Kiyan V, & QueirozC( 2013) Effect of chlorhexidine on the 18-month clinical performance of two adhesivesJournal of Adhesive Dentistry15(
    3
    ) 287– 292.
  • 98.
    Hafer M, Jentsch H, Haak R, & SchneiderH( 2015) A three-year clinical evaluation of a one-step self-etch and a two-step etch-and-rinse adhesive in non-carious cervical lesionsJournal of Dentistry43(
    3
    ) 350– 361.
  • 99.
    Kubo S, Kawasaki K, Yokota H, & HayashiY( 2006) Five-year clinical evaluation of two adhesive systems in non-carious cervical lesionsJournal of Dentistry34(
    2
    ) 97– 105.
  • 100.
    Matis B, Cochran M, Carlson T, Guba C, & EckertG( 2004) A three-year clinical evaluation of two dentin bonding agentsJournal of the American Dental Association135(
    4
    ) 451– 457.
  • 101.
    Türkün L ( 2005) The clinical performance of one- and two-step self-etching adhesive systems at one yearJournal of the American Dental Association136(
    5
    ) 656– 664.
  • 102.
    Pena CE, Rodrigues JA, Ely C, Giannini M, & ReisAF( 2016) Two-year randomized clinical trial of self-etching adhesives and selective enamel etchingOperative Dentistry41(
    3
    ) 249– 257.
  • 103.
    Sartori N, Pacheco E, Souza PTdR, Lopes GC, & PeruchiLD( 2011) Performance clínica de dois sistemas adesivos em lesôes cervicais não cariosas: 30 meses de acompanhamentoArquivos do Centro de Estudos da Faculdade de Odontologia da Universidade Federal de Minas Gerais47(
    03
    ) 119– 126.
  • 104.
    Stojanac I, Premovic M, Ramic B, Drobac M, Stojsin I, & PetrovicL( 2013) Noncarious cervical lesions restored with three different tooth-colored materials: two-year resultsOperative Dentistry38(
    1
    ) 12– 20.
  • 105.
    Abdalla A & García-GodoyF( 2006) Clinical evaluation of self-etch adhesives in Class V non-carious lesionsAmerican Journal of Dentistry19(
    5
    ) 289– 292.
  • 106.
    Lawson N, Robles A, Fu C, Lin C, Sawlani K, & BurgessJ( 2015) Two-year clinical trial of a universal adhesive in total-etch and self-etch mode in non-carious cervical lesionsJournal of Dentistry43(
    10
    ) 1229– 1234.
  • 107.
    Meerbeek B, Braem M, Lambrechts P, & VanherleG( 1993) Two-year clinical evaluation of two dentine-adhesive systems in cervical lesionsJournal of Dentistry21(
    4
    ) 195– 202.
  • 108.
    Meerbeek B, Peumans M, Gladys S, Braem M, Lambrechts P, & VanherleG( 1996) Three-year clinical effectiveness of four total-etch dentinal adhesive systems in cervical lesionsQuintessence International27(
    11
    ) 775– 784.
  • 109.
    Tyas MJ ( 1991) 3-year clinical-evaluation of dentin bonding agentsAustralian Dental Journal36(
    4
    ) 298– 301.
  • 110.
    Higgins J & GreenS( 2010) Cochrane Handbook for Systematic Reviews of Interventions
    Wiley-Blackwell
    ,
    Hoboken, NJ
    .
  • 111.
    Choi KK, Condon JR, & FerracaneJL( 2000) The effects of adhesive thickness on polymerization contraction stress of compositeJournal of Dental Research79(
    3
    ) 812– 817.
  • 112.
    Reis A, Carrilho M, Breschi L, & LoguercioAD( 2013) Overview of clinical alternatives to minimize the degradation of the resin-dentin bondsOperative Dentistry38(
    4
    ) e1– e25.
  • 113.
    Mahn E, Rousson V, & HeintzeS( 2015) Meta-analysis of the influence of bonding parameters on the clinical outcome of tooth-colored cervical restorationsJournal of Adhesive Dentistry17(
    5
    ) 391– 403.
  • 114.
    Swift E, Perdigão J, Heymann H, Wilder A, Bayne S, May K, Sturdevant J, & RobersonT( 2001) Eighteen-month clinical evaluation of a filled and unfilled dentin adhesiveJournal of Dentistry29(
    1
    ) 1– 6.
  • 115.
    van Dijken JW ( 1994) Clinical evaluation of four dentin bonding agents in Class V abrasion lesions: a four-year follow-upDental Materials10(
    5
    ) 319– 324.
  • 116.
    Szesz A, Parreiras S, Martini E, Reis A, & LoguercioA( 2017) Effect of flowable composites on the clinical performance of non-carious cervical lesions: a systematic review and meta-analysisJournal of Dentistry6511– 21.
  • 117.
    Van Meerbeek B, Conn LJ Jr, Duke ES, Eick JD, Robinson SJ, & GuerreroD( 1996) Correlative transmission electron microscopy examination of nondemineralized and demineralized resin-dentin interfaces formed by two dentin adhesive systemsJournal of Dental Research75(
    3
    ) 879– 888.
  • 118.
    Di Hipolito V, Reis AF, Mitra SB, & de GoesMF( 2012) Interaction morphology and bond strength of nanofilled simplified-step adhesives to acid etched dentinEuropean Journal of Dentistry6(
    4
    ) 349– 360.
  • 119.
    Osorio E, Toledano M, Yamauti M, & OsorioR( 2012) Differential nanofiller cluster formations in dental adhesive systemsMicroscopy Research and Technique75(
    6
    ) 749– 757.
  • 120.
    Van Landuyt KL, De Munck J, Mine A, Cardoso MV, Peumans M, & Van MeerbeekB( 2010) Filler debonding & subhybrid-layer failures in self-etch adhesivesJournal of Dental Research89(
    10
    ) 1045– 1050.
  • 121.
    Van Landuyt KL, Peumans M, De Munck J, Lambrechts P, & Van MeerbeekB( 2006) Extension of a one-step self-etch adhesive into a multi-step adhesiveDental Materials22(
    6
    ) 533– 544.
  • 122.
    Eick JD, Robinson SJ, Byerley TJ, Chappell RP, Spencer P, & ChappelowCC( 1995) Scanning transmission electron microscopy/energy-dispersive spectroscopy analysis of the dentin adhesive interface using a labeled 2-hydroxyethylmethacrylate analogueJournal of Dental Research74(
    6
    ) 1246– 1252.
  • 123.
    Linden LA, Kallskog O, & WolgastM( 1995) Human dentine as a hydrogelArchives of Oral Biology40(
    11
    ) 991– 1004.
  • 124.
    Kim JS, Cho BH, Lee IB, Um CM, Lim BS, Oh MH, Chang CG, & SonHH( 2005) Effect of the hydrophilic nanofiller loading on the mechanical properties and the microtensile bond strength of an ethanol-based one-bottle dentin adhesiveJournal of Biomedical Materials Research Part B: Applied Biomaterials72(
    2
    ) 284– 291.
  • 125.
    Lohbauer U, Wagner A, Belli R, Stoetzel C, Hilpert A, Kurland HD, Grabow J, & MullerFA( 2010) Zirconia nanoparticles prepared by laser vaporization as fillers for dental adhesivesActa Biomaterials6(
    12
    ) 4539– 4546.
  • 126.
    Cheng L, Zhang K, Weir MD, Melo MA, Zhou X, & XuHH( 2015) Nanotechnology strategies for antibacterial and remineralizing composites and adhesives to tackle dental cariesNanomedicine10(
    4
    ) 627– 641.
  • 127.
    Higgins JP, Altman DG, Gotzsche PC, Juni P, Moher D, Oxman AD, Savovic J, Schulz KF, Weeks L, Sterne JA, Cochrane Bias Methods G, & Cochrane Statistical Methods G( 2011) The Cochrane Collaboration’s tool for assessing risk of bias in randomised trialsBMJ343d5928.
  • 128.
    Reis A, de Geus JL, Wambier L, Schroeder M, & LoguercioAD( 2018) Compliance of randomized clinical trials in noncarious cervical lesions with the CONSORT statement: a systematic review of methodologyOperative Dentistry43(
    3
    ) E129– E151.
    a References 39, 41, 42, 44, 45, 90, 93–101. b References 38, 39, 42–45, 90, 91, 93–95, 97, 99, 101–104. c References 36, 38, 42, 44, 91, 92, 94, 100, 106, 108, 109. d References 41, 43–45, 91, 93, 95, 97, 98, 101–105. e References 36, 43, 44, 89–91, 94–100, 103–107. f References 41, 44, 45, 90, 93, 94, 97, 106. g References 41, 44, 45, 90, 91, 94, 95, 97, 98, 100, 101, 103, 105, 106. h References 36, 38, 39, 41–45, 89–94, 96, 97, 99–109. i References 41–45, 89–94, 96, 97, 100–108. j References 36, 41, 43–45, 89, 90, 93, 97, 100–106, 108. k References 89, 93, 94, 105, 107–109, 114, 115.
Copyright: 2021
Figure 1.
Figure 1.

Flowchart diagram showing the number of articles obtained in the different phases of the study.

Figure 2.
Figure 2.

Summary of the risk of bias assessment for the 27 studies included in the meta-analysis according to the Cochrane Collaboration tool. The risk of bias tool contains six domains: sequence generation, allocation concealment, blinding of the outcome assessors, incomplete outcome data, selective outcome reporting, and other possible sources of bias. Each domain was judged to be at low, unclear, or high risk of bias according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0

Figure 3.
Figure 3.

Forest plot of restorations that suffered retention loss comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Figure 4.
Figure 4.

Forest plot of restorations that suffered retention loss comparing filled vs unfilled adhesives at 3 and 5 or more years.

Figure 5.
Figure 5.

Forest plot of restorations with marginal discoloration comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Figure 6.
Figure 6.

Forest plot of restorations with marginal discoloration comparing filled vs unfilled adhesives at 3 years.

Figure 7.
Figure 7.

Forest plot of restorations with secondary caries comparing filled/nanofilled vs unfilled adhesives at 12 to 18 months and 24 to 30 months.

Figure 8.
Figure 8.

Forest plot of restorations with secondary caries comparing filled vs unfilled adhesives at 3 years.

Contributor Notes

Juliana L de Geus, Department of Dentistry, Paulo Picanço School of Dentistry, Fortaleza, CE, Brazil

Bianca M Maran, Department of Dentistry, State University of Ponta Grossa, PR, Brazil

Karla A Cabral, Department of Dentistry, Paulo Picanço School of Dentistry, Fortaleza, CE, Brazil

Andres Dávila-Sánchez, Professor, Departamento de Odontología Restauradora y Biomateriales, Colegio de Ciencias de la Salud, Escuela de Odontología, Universidad San Francisco de Quito USFQ, Quito, Ecuador

Chane Tardem, School of Dentistry, Federal Fluminense University, Rio de Janeiro, RJ, Brazil

Marcos O Barceleiro, School of Dentistry, Federal Fluminense University, Rio de Janeiro, RJ, Brazil

Siegward D Heintze, Research & Development, Ivoclar Vivadent, Schaan, Liechtenstein

Alessandra Reis, Department of Dentistry, State University of Ponta Grossa, PR, Brazil

*Alessandro D Loguercio, Department of Dentistry, State University of Ponta Grossa, PR, Brazil

*Corresponding author: Av General Carlos Cavalcanti, 4748, Ponta Grossa, Paraná, Brazil; e-mail: aloguercio@hotmail.com
Accepted: 22 Jan 2020
  • Download PDF