Effect of eugenol-containing sealer on marginal adaptation of dentine-bonded resin fillings

Aim Eugenol is claimed to interfere with the polymerization. of composite r esins and to affect shear bond strengths of dentine-bonded composite restor ations. Eugenol-based sealers are used during root canal treatment in teeth that may require build-ups or extensive restorations. Unfortunately, the a dverse effect of eugenol has mostly been assessed in shear bond tests and t his variable may be clinically inappropriate. The current study evaluated t he effect of eugenol in a eugenol-based endodontic sealer on marginal adapt ation of composite resin restorations with and without thermo-mechanical st ress. Methodology Thirty Class V cavities with half of the cavity margins in dent ine and half of the cavity margins in enamel were prepared in extracted hum an premolars and then divided into 5 groups. Teeth in group 1 were not cont aminated with eugenol. Cavities in groups 2-4 were contaminated with a euge nol-based sealer (Tubli-Seal, Kerr) and cleaned with: (i) sandblasting, (ii ) bur finishing alone or (iii) burfinishing combined with swabbing with alc ohol. These 4 groups were temporized for 6 weeks (Ketac, ESPE), whilst grou p 5 received no eugenol, was not temporized and acted as the control. Cavit ies were restored with Tetric Ceram using Syntac Classic (Vivadent) as a de ntine-bonding agent. The specimens were then thermo-mechanically stressed. The percentages of marginal adaptation in dentinal and enamel margins were assessed in a SEM at x200 magnification before and after stress using a rep lica method. Mean percentages of marginal adaptation were calculated and co mpared using a two way-ANOVA (influence of eugenol and cleaning procedure) and non-parametric tests. Results Marginal adaptation in enamel exceeded 95% and 92% in all specimens before and after thermo-mechanical stess, respectively. Before stress, mar ginal adaptation in dentine ranged from 92.3 +/- 7.9% to 95.7 +/- 6.2% in g roups 1-5. After stress, the percentage of marginal adaptation in dentine d ecreased significantly overall (P < 0.05, range 39.8 +/- 21.1% to 82.9 +/- 13.7%). The effect of contamination with eugenol was not significant (P > 0 .05); in contrast, there was a significantly beneficial effect when the ent ire cavity was finished with burs (P < 0.01). Conclusions Under the conditions of this study, the eugenol containing seal er did not significantly impair marginal adaptation in dentinal margins of mixed Class V restorations when bur finishing was employed before placement . However, no other cleaning method was sufficient to produce acceptable fi gures of marginal adaptation.