Longer Polymerization Time Tied to Better Long-Term Restoration Retention in Non-Carious Cervical Lesions

A new study published in the Journal of Dentistry suggests that longer polymerization time is beneficial for restoration retention in non-carious cervical lesions.

Study Overview

A study was conducted to evaluate the effect of prolonged (P) polymerization time of a universal adhesive system applied in etch-and-rinse (ER) or self-etch (SE) strategies on the clinical performance of restorations in non-carious cervical lesions (NCCLs), after 36 months of clinical service.

Methodology

A total of 140 restorations were randomly placed in 35 subjects according to the polymerization time groups:

• ER (10 s)
• ER-P (40 s)
• SE (10 s)
• SE-P (40 s) at 1,200 mW/cm²

Composite resin was placed incrementally. The restorations were evaluated immediately and after 6, 12, 18, and 36 months using the FDI criteria. Data were analyzed using the Kaplan-Meier survival test for retention loss, and the Kruskal-Wallis’ test for secondary outcomes (α = 0.05).

Results

After 36 months, 19 restorations were lost:

• ER: 6
• ER-P: 2
• SE: 9
• SE-P: 2

The retention rates were:

• 82.3% for ER
• 94.1% for ER-P
• 73.5% for SE
• 94.1% for SE-P

There was a significant difference between ER vs. ER-P and SE vs. SE-P, as well as ER vs. SE-P and ER-P vs. SE (p < 0.0001).

Minor defects were observed in 18 restorations for the marginal staining criteria:

• ER: 5
• ER-P: 2
• SE: 8
• SE-P: 3

And in 33 restorations for the marginal adaptation criteria:

• ER: 11
• ER-P: 4
• SE: 12
• SE-P: 6

(p > 0.05). No restorations showed a recurrence of caries or postoperative sensitivity.

Conclusion

A prolonged polymerization time of 40 seconds improves the clinical performance of the universal adhesive for both adhesive strategies evaluated, even after 36 months. Prolonging the polymerization time of a universal adhesive from 10 s to 40 s has been shown to improve its clinical performance when used in NCCLs.

Reference

Romina Ñaupari-Villasante, André de Freitas, Viviane Hass, Thalita P. Matos, Sibelli O. Parreiras, Alessandra Reis, Mario F. Gutiérrez, Alessandro D. Loguercio. Prolonged polymerization of a universal adhesive in non-carious cervical lesions: 36-month double-blind randomized clinical trial. Journal of Dentistry, 2023, 104823, ISSN 0300-5712. https://doi.org/10.1016/j.jdent.2023.104823.

Keywords

polymerization time, restoration retention, non-carious cervical lesions, universal adhesive system; prolonged polymerization time; non-carious cervical lesion; clinical trial, Journal of Dentistry