Effectiveness of Adhesives in Enamel at Class-V-Cavities after Three-year Water-storage

Objective: Evaluation of the effectiveness of 14 adhesive systems combined with composite resins at the enamel margins of Class-V-cavities after three-year waterstorage. Methods: In 112 extracted human teeth, per group 8 Class-V- cavities were prepared (approximately 4 mm high, 3 mm wide and 1,5 mm deep, one half of the margin length was located in enamel). The etch-and-rinse adhesives ART Bond (AR), Syntac (SY), OptibondFL (OF), Excite (EX), Optibond SoloPlus (OS), PQ1 (PQ), and the self-etching adhesives AquaPrime&Monobond (AM), Clearfil LinerBond2V (CL), Clearfil SEBond (CS), AdheSE (AD), Prompt L-Pop 2000 (PL2), Adper Prompt L-Pop (AP), One-Up Bond F (OU), iBond (IB) were used in combination with the corresponding composite resin. After 21 days of waterstorage (WS), after a first thermocycling (TC), after additional WS of one year, after a 2. TC (again 2000 cycles, 5° to 55°C), after another WS of two years and after a 3. TC replicas were taken and a quantitative margin analysis in the SEM (magnification 200X) was performed using defined criteria. Results: The results after 3-year waterstorage and 3 TC for ”continuous margin” in % of total margin length in enamel (median/mean/standard deviation) were evaluated as OF (98.1/98.3/1.5), AT (98.9/97.1/3.2), SY (96.9/97.4/2.3), EX (100/97.5/3.2), OS (98.1/97.0/3.2), PQ (96.9/97.4/2.5), CL (96.8/96.4/3.3), AM (97.3/97.1/2.8), CS (100/99.1/1.4), AD (98.4/98.2/2.0), PL2 (97.1/95.4/3.4), AP (95.5/94.9/3.8), OU (94.9/94.3/4.0), IB (94.6/94.4/4.0). The statistical analysis for the data after the 3. TC using the Kruskal-Wallis-test found no statistical significant difference (p=0.072). However, the results for the four all-in-one-adhesives were at the end of the ranking showing the highest standard deviations. Conclusion: All tested adhesive systems showed a high effectiveness in sealing the enamel margins after 3 year waterstorage even for the self-etching all-in-one-adhesives. However, there is a trend (p=0.072) that the two-step etch&rinse and the two-step self-etch systems are more reliable.