A 13-year clinical evaluation of two three-step etch-and-rinse adhesives in non-carious class-V lesions

Clinical effectiveness of contemporary adhesives for the restoration of non-carious cervical lesions. A systematic review

OBJECTIVES

The aim of this systematic review was to evaluate the clinical effectiveness of contemporary adhesives for the restoration of non-carious cervical lesions (NCCLs) in terms of restoration retention as a function of time.

METHODS

Medline Ovid and IADR abstracts were reviewed for NCCLs clinical trials from 1950 to 2013. The reference list of all eligible trials and relevant review articles was checked to find additional studies. The review did not have any language restrictions. Only randomized controlled clinical trials that evaluated at least two adhesives for a follow-up period of at least 18 months were included. Materials with adhesive potential were categorized into 6 main classes: 3-step etch&rinse adhesives (3E&Ra's), 2-step etch&rinse adhesives (2E&Ra's), 2-step self-etch adhesives (2SEa's), 1-step self-etch adhesives (1SEa's), glass-ionomers (GI's) and self-adhesive composites (SAC's). The first four can bond restorative composite to tooth tissue. Both 2SEa and 1SEa were further sub-divided in 'mild' and 'intermediately strong (1/2SEa_m), with a pH≥1.5, and 'strong' (1/2SEa_s), with a pH<1.5. From the restoration retention rates as a function of time the average annual failure rate (AFR) per adhesive and adhesive class was calculated.

RESULTS

The lowest AFR scores [mean (SD)] were recorded for GI [2.0 (1.4)] shortly followed by 2SEa_m [2.5 (1.5)], 3E&Ra [3.1 (2)] and 1SEa_m [3.6 (4.3)] (Tukey Contrasts: p>0.05). Significantly higher AFR scores were recorded for 1SEa_s [5.4 (4.8)], 2E&R [5.8 (4.9)], and 2SEa_s [8.4 (7.9)] (p>0.05). In addition, significant differences in AFR were noticed between adhesives of the same class (Kruskal-Wallis sum test: p>0.05), except for GI (p=0.7) and 2SEa_m (p=0.1). Finally, selective enamel etching did not significantly influence the retention rate of SEa (AFR SEa_etch=0.43 (0.49), AFR SEa_non-etch=1.43 (1.77).

SIGNIFICANCE

The adhesive approach significantly influences the clinical effectiveness of adhesives in NCCLs. Within each class, except for GI, there was a wide variation in clinical bonding effectiveness.

Seven-year clinical performance of resin composite versus resin-modified glass ionomer restorations in noncarious cervical lesions

PURPOSE

The purpose of this study was to comparatively assess the seven-year clinical performance of a one-bottle etch-and-rinse adhesive with resin composite (RC) and resin-modified glass ionomer (RMGI) restorations in noncarious cervical lesions.

METHODS AND MATERIALS

One operator placed 70 restorations (35 restorations in each group) in 30 patients under rubber dam isolation without mechanical preparation. The restorations were directly assessed by two independent examiners, using modified US Public Health Service criteria at baseline and 6, 12, 24, 60, and 84 months. The obtained data were tabulated and statistically analyzed using the Fisher and McNemar tests. A difference was significant if p<0.05.

RESULTS

Twenty patients were available for recall after seven years (66.6%), and 25 RC and 26 RMGI restorations out of 70 restorations were evaluated. Excellent agreement was registered for all criteria between examiners (κ≥0.85). Alfa and bravo scores were classified as clinically acceptable. The McNemar test detected significant differences within RC restorations between baseline and seven-year evaluations for anatomic form, marginal integrity, and retention (p<0.05). For RMGI restorations, a significant difference was identified for marginal integrity (p<0.05). As to material comparison, the Fisher exact showed a better retention performance for RMGI restorations than for RC restorations (p<0.05). Twelve composite restorations were dislodged (52.0% retention) and three ionomer restorations were lost (88.5% retention). The cumulative success rate for RC and RMGI was 30% and 58.1%, respectively.

CONCLUSIONS

After seven years of service, the clinical performance of RMGI restorations was superior to that of the adhesive system/resin composite restorations in this study.

Anterior composite restorations in clinical practice: findings from a survey with general dental practitioners

Objectives

The aim of this study was to assess technical preferences of general dental practitioners when restoring anterior composite restorations. How the level of clinical experience or post-graduate training infuenced their options was also tested.

Material and Methods

A cross-sectional study was performed using a questionnaire with general dental practitioners (GDPs) (n=276) in Southern Brazil. Information regarding post graduation training (specialization, master's or PhD degree) and linical experience (years since completing graduation) were gathered. The options regarding anterior composite restorations (type of composite, adhesive system, light curing unit, polishing procedures and rubber dam use) were collected. Data were submitted to descriptive analysis and associations were tested.

Results

Response rate was 68% (187). GDPs selected microhybrid composite (52%) and 2-step total etch adhesive system (77%). LED was the preferred method of activation for 72.8%. Immediate polishing was preferred by 75%, using a combination of techniques. Most of the respondents (74.3%) did not use rubber dam. More experienced clinicians used more halogen lights (p<0.022), performed more light monitoring (p<0.001) and were resistant to use rubber dam (p<0.012). Dentists with post-graduation training used 3-etch-and-rinse system more frequently (p<0.04), usually monitored light intensity (p<0.014) and placed rubber dam more frequently (p<0.044).

Conclusions

Hybrid composite, simplifed adhesives, LED units and immediate polishing were preferred by Southern Brazilian dentists for anterior composite restorations. Few dentists used rubber dam to perform composite restorations in anterior teeth. Clinical experience and post-graduation training infuenced the dentists' choices.

A comprehensive laboratory screening of three-step etch-and-rinse adhesives

OBJECTIVES

This study evaluated several bonding (microtensile bond strengths [μTBS], nanoleakage [NL], and in situ degree of conversion [ISDC] on dentin) and mechanical properties (ultimate tensile strength [UTS], degree of conversion [DC], water sorption [WS], and solubility [SL] in water) of four three-step etch-and-rinse adhesives in the short term.

METHODS

A total of 28 molars were used in this study. The dentin surfaces were bonded with the following adhesives: All-Bond 3 (ALB3); Fusion Duralink (FSDL); Optibond FL (OBFL), and Scotchbond Multi-Purpose (SBMP). After each adhesive-system application, composite resin build-ups were added. For bonding tests, specimens were sectioned in order to obtain bonded sticks. The sticks were divided to be tested for μTBS (0.5 mm/min), for NL (n=2), and ISDC (n=2). For NL, they were immersed in 50% silver nitrate and analyzed by scanning election microscopy. For ISDC, the hybrid layer was evaluated by micro-Raman spectroscopy. An hourglass-shaped matrix (UTS) or disk-shaped matrix (WS and SL) was filled with primer and adhesive (1:1 ratio) and light-polymerized. For UTS evaluation, the specimens were tested under tension. For WS and SL, specimens were desiccated and stored in distilled water to evaluate water diffusion kinetics over a 28-day period. The DC of the adhesives was evaluated by Fourier transformed infrared spectroscopy. The data from each test were analyzed by appropriate statistical methods.

RESULTS

OBFL resulted in the highest μTBS, lower NL, higher ISDC and DC, and higher UTS than other adhesives (p<0.05), as well as lower WS (similar to ALB3 and FSDL) and SL (similar to ALB3 and SBMP) (p>0.05). ALB3 showed a higher NL and the lowest DC value. FSDL showed the highest NL and SL and the lowest ISDC. SBMP showed the lowest pattern of WS (p<0.05)CONCLUSION: OBFL showed the best results in all the properties evaluated, and it can be considered the gold standard of the three-step etch-and-rinse adhesive systems.

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.

Change of optical properties of contemporary resin composites after one week and one month water ageing

OBJECTIVES

To compare color and translucency changes after water ageing for one-week and one-month in light and dark shades of contemporary polychromatic resin composites.

METHODS

Enamel (e) and dentine (d), light and dark (A1 and A4 or equivalents) shades were selected from the composites Enamel-Plus HRi/Micerium, Miris-2/Coltene, IPS Empress-Direct/Ivoclar and Filtek-Supreme/3M ESPE and light and dark shades from the TPH-Spectum/Densply monochromatic composite. Five disks (d = 10mm, h = 1mm) per material, enamel/dentine and light/dark shade were prepared. A colorimetric evaluation, over white and black background, according to the CIELab system was performed just after preparation and after one-week and one-month dark water-storage at 37°C. Color (ΔEab) and translucency (ΔTP) differences were calculated. Results were analysed by ANOVA and Scheffe's test, paired t-test and linear regression analysis (a = 0.05).

RESULTS

One-week water ageing provided a wide range of ΔEab values (0.79 Filtek(e)/D2 to 5.19 Filtek(d)/A1) and ΔTP values (-2.74 Hri/UD1 to 1.03 TPH/A1). After one-month water ageing ΔEab ranged from 1.09 Filtek(e)/D2 to 7.94 Filtek(d)/A1 and ΔTP values from -2.71Hri/UD1 to 1.07 Filtek(d)/A4. Significant changes in ΔEab between one-week and one-month water ageing were noted for Filtek and Miris dentine and Miris light enamel shades. As for ΔTP, significant difference was recorded only for IPS(e)/A4. ΔEab was significantly correlated with ΔL, Δα, Δb and ΔTP after one-week and with ΔL and Δα after one-month ageing.

CONCLUSIONS

Water ageing caused remarkable color changes, which were material and shade depended. Thirteen out of eighteen of the tested composites exhibited clinically perceptible (ΔEab>2.6) color changes even after short water ageing period.

A randomized clinical trial evaluating the success rate of ethanol wet bonding technique and two adhesives

BACKGROUND

Composite resin restorations may have a short lifespan due to the degradation of resin-dentin interface. Ethanol wet bonding technique may extend the longevity of resin-dentin bond. The purpose of this one year randomized clinical trial was to compare clinical performance of two adhesives with ethanol wet bonding technique.

MATERIALS AND METHODS

This randomized clinical trial was performed on 36 non-carious cervical lesions in 12 patients restored with composite resin using one of the following approaches: 1. OptiBond FL (Kerr, USA); 2. Clearfil SE Bond (Kuraray, Japan) with enamel etching and 3. Ethanol wet bonding technique with the part of adhesive of OptiBond FL. The clinical success rate was assessed after 24 h, 6, 9 and 12 months according to the United States Public Health Service (USPHS) criteria: Marginal discoloration, marginal defect, retention rate, caries occurrence, and postoperative sensitivity. The tooth vitality was also assessed.

RESULTS

The retention rate was 100% at baseline and at 6 months follow up for all types of bonding protocols and was 91.67% at 9 and 12 months follow up for ethanol wet bonding group. None of the restorations in three groups showed marginal defects, marginal discoloration or caries occurrence and were vital after 12 months. There was no statistically significant difference between three groups after 12 months follow up (p value = 0.358).

CONCLUSIONS

Composite restorations placed using ethanol wet bonding technique presented equal performance to the other groups.

Two-year clinical evaluation of composite resins in non-carious cervical lesions

OBJECTIVE

The purpose of this double-blind, randomised trial was to compare the clinical performance of a hybrid composite (Clearfil AP-X, Kuraray, Tokyo) and a nanocomposite (Filtek Z350, 3M ESPE, St. Paul, MN) over a period of 2 years in non-carious class V lesions using a modified US Public Health Service (USPHS) system.

METHODS

Forty-six patients with at least one pair of equivalent non-carious cervical lesions under occlusion and a mean age of 44.1 years (range 27-66 years; median 45 years) were enrolled in this study. A total of 116 restorations (58 with each material) were placed according to manufacturer's instructions by two calibrated operators. The restorations were evaluated at baseline and at 6, 12 and 24 months after placement using the USPHS criteria for retention, colour match, marginal discolouration, marginal adaptation, anatomic form, surface texture and secondary caries. Statistical analysis was conducted using the Cochran and the McNemar tests at a significance level of 5% (P < 0.05).

RESULTS

No surface texture changes or secondary caries were detected in association with any restorations. The retention rates for Clearfil AP-X (100%) and for Filtek Z350 (91.38%) did not differ significantly (P > 0.05). Two Z350 restorations were completely lost after 2 years. No significant differences were observed in the colour match, marginal discolouration, marginal adaptation or anatomic form.

CONCLUSIONS

There were no significant differences in the clinical performances between the materials.

CLINICAL RELEVANCE

Both restorative materials exhibited acceptable clinical performance in class V non-carious lesions 2 years post-restoration.

Durability of bonds and clinical success of adhesive restorations

Resin-dentin bond strength durability testing has been extensively used to evaluate the effectiveness of adhesive systems and the applicability of new strategies to improve that property. Clinical effectiveness is determined by the survival rates of restorations placed in non-carious cervical lesions (NCCL). While there is evidence that the bond strength data generated in laboratory studies somehow correlates with the clinical outcome of NCCL restorations, it is questionable whether the knowledge of bonding mechanisms obtained from laboratory testing can be used to justify clinical performance of resin-dentin bonds. There are significant morphological and structural differences between the bonding substrate used in in vitro testing versus the substrate encountered in NCCL. These differences qualify NCCL as a hostile substrate for bonding, yielding bond strengths that are usually lower than those obtained in normal dentin. However, clinical survival time of NCCL restorations often surpass the durability of normal dentin tested in the laboratory. Likewise, clinical reports on the long-term survival rates of posterior composite restorations defy the relatively rapid rate of degradation of adhesive interfaces reported in laboratory studies. This article critically analyzes how the effectiveness of adhesive systems is currently measured, to identify gaps in knowledge where new research could be encouraged. The morphological and chemical analysis of bonded interfaces of resin composite restorations in teeth that had been in clinical service for many years, but were extracted for periodontal reasons, could be a useful tool to observe the ultrastructural characteristics of restorations that are regarded as clinically acceptable. This could help determine how much degradation is acceptable for clinical success.

Nanoleakage Distribution at Adhesive-Dentin Interfaces in 3D

In spite of its role in the degradation of tooth-biomaterial interfaces, reports on nanoleakage are largely inconsistent. The aim of this work was to assess nanoleakage patterns qualitatively and quantitatively in 3D, to determine the influence of direction, position, and inclination of the field-of-view. Therefore, we applied a gold-standard 3-step etch-and-rinse adhesive to bur-cut dentin surfaces, after which interface samples were sectioned, infiltrated with an ammoniacal silver-nitrate solution, and embedded by common TEM procedures. High-resolution 3D models of interfaces were then generated by FIB and electron tomography, following strict conditions determined by Monte Carlo simulations. Inverted images in FIB tomography disclosed morphological characteristics analogous to those revealed by TEM. Quantitative analysis revealed large variations in silver-nitrate uptake between 2D image projections in different directions. Furthermore, silver-nitrate fractions in individual 2D image projections were seldom related to the total 3D volumetric fraction. Electron tomography showed that inclination also affected the morphology of silver-nitrate patterns. In conclusion, conventional nanoleakage evaluation is heavily influenced by direction, position, and inclination of the field-of-view, and thus may contain artifacts.