Clinical performance of the ethanol-wet bonding technique with different adhesive systems in noncarious cervical lesion restorations: a 6-year randomized clinical trial.

OBJECTIVES

This randomized clinical trial evaluated the six-year clinical performance of the ethanol-wet bonding technique (EWBT) combined with different adhesive protocols in non-carious cervical lesions (NCCLs). The research question was whether EWBT improves long-term restoration retention compared with conventional water-wet bonding.

MATERIAL AND

METHODS

Patients presenting at least one NCCL, regardless of lesion etiology (abrasion, erosion, abfraction, or mixed), were included. A total of 148 NCCLs were randomized at the restoration level into four groups: [NE] water-wet bonding with a three-step etch-and-rinse adhesive (Adper Scotchbond Multi-Purpose, 3M ESPE); [EMP] EWBT + Adper Scotchbond Multi-Purpose (3M ESPE); [EB] EWBT + hydrophobic bonding resin (Adper Scotchbond Multi-Purpose Bond, 3M ESPE); and [EU] EWBT + universal adhesive (Single Bond Universal, 3M ESPE). EWBT consisted of applying 100% ethanol actively for 60 s to dentin prior to adhesive application. All restorations were placed using a nanohybrid composite resin (Filtek Z350 XT, 3M ESPE). Clinical evaluations were performed at baseline, 6, 18 months and after six years using modified USPHS criteria. The unit of analysis was the restoration. Intergroup comparisons at each time point were performed using Fisher's exact test, and survival analysis was conducted using Kaplan-Meier estimates and log-rank tests (α = 0.05).

RESULTS

After six years, 42 patients (108 restorations) were clinically evaluated (72.9% recall), while all 148 restorations were included in the intention-to-treat analysis. Survival rates were 88.9% (NE), 81.1% (EU), 77.8% (EMP), and 48.7% (EB). The EB group showed significantly lower survival than all other groups (log-rank, p = 0.008). No significant differences were observed among the hydrophilic protocols (p > 0.05).

CONCLUSIONS

The effectiveness of EWBT is influenced by the hydrophilicity of the adhesive system. Hydrophilic adhesives showed stable long-term performance regardless of ethanol pretreatment, whereas the use of EWBT with a purely hydrophobic bonding resin resulted in significantly reduced retention.

CLINICAL RELEVANCE: EWBT does not improve longevity when used with hydrophilic adhesives but may compromise performance when associated with simplified hydrophobic bonding strategies.