Post-operative Sensitivity and Longevity of Universal Adhesives: A Randomized Clinical Trial

Objectives: To evaluate the clinical performances of universal adhesives, employed either with etch-and-rinse or self-etch modes.
Methods: 75 patients, who matched inclusion criteria, were enrolled for this randomized clinical trial, for a total of 156 first class restorations performed by the same expert operator and equally divided among three groups according to the adhesive used

SU, ScotchBond Universal (3M): 50;
AU, AllBond Universal (Bisco): 52;
FU, Futurabond U (VOCO): 54.

Each restoration was performed using the same clinical procedure and composite material (Grandioso, VOCO). Each group was divided into two subgroups according to the approach:

ER, Etch&rinse: 30s etching of the enamel, 15s etching of the dentine followed by 60s rinse and dry + adhesive application.
SE, Self-Etch: no etching, only adhesive application.

After 36.3 months, 70 patients with 145 restorations were visited (SU: 47; AU: 48; FU: 50; drop-out: 5). Restorations performed were examined and evaluated in accordance with USPHS criteria by two calibrated blind operators.
One-way ANOVA test and Bonferroni post-hoc were performed (p < 0,05).
Results: Clinical performance of composite restoration wasn't influenced by neither the adhesive systems (p=0.061) nor the application mode (ER vs SE) (p=0.058).
None of the patients showed any complications at 36 months follow-up and no restoration needed a re-intervention, even if some showed Charlie values in some criteria.
SE showed increased marginal discoloration and worse marginal integrity.
“Secondary caries” criteria showed some Bravo values in SE.
Most of the cases didn't show any post-op sensitivity, thus indicating a stable hybrid layer over three year of clinical function.
Conclusions: Universal adhesives seems to have better performances in ER mode in posterior teeth direct restorations. SE approach seems to show a worse outcome, suggesting the pre-etching of enamel margins before the adhesive system application is recommended.