Marginal Adaptation Of Self-Etching Adhesive Systems. An In Vitro Investigation In Class V Cavities U. Blunck*, J.-F. Roulet (Dept. Of Operative And Preventive Dentistry, Charité, Humboldt University Of Berlin, Germany) Self-etching adhesive systems were introduced in order to reduce the technique sensitivity of total etch systems regarding the wettability of the conditioned dentin. These systems have to be applied either in two different solutions or in two layers. Just recently a new system was introduced which can be applied after mixing in only one layer. The purpose of this in-vitro study was to evaluate the marginal adaptation of self-etching adhesive systems to enamel and dentin at Class-V-restorations.   In extracted human teeth 80 Class V cavities were prepared as an oval form of about 4 mm high and 3 mm wide and about 1.5 mm deep and divided into 10 groups (n=8). Half of the margin length was situated in dentin with a butt joint preparation, the enamel margins were beveled.   The cavities were filled using Clearfil Liner Bond 2V (CLB), Clearfil SE Bond (CSB), Resulcin AquaPrime & Monobond (APM), Etch & Prime 3.0 (EP), Prompt L-Pop (LP1) for compomers and Prompt L-Pop (LP2) for compomers and composites in combination with the corresponding composite resin. LP1 was used in combination with Tetric Ceram, LP2 in combination with Promptfil (LP2P) and with Tetric Ceram (LP2T). The different bonding systems were applied according to the manufacturer’s instructions, only LP1 and LP2, were used both, with (+LC) and without (-LC) light-curing prior to the application of the composite resins. After water storage of 21 days, before and after a thermocycling procedure (TC) replicas were taken and a quantitative margin analysis for the margins in dentin and in enamel in the SEM was performed at a magnification of 200 x. The statistical analysis of the results with KRUSKAL-WALLIS-test and BONFERRONI-adjustment showed no statistically significant difference (p>0.05) between the results at both, enamel and dentin, in groups using adhesive systems with light curing before the application of the composite resins. Using the Prompt L-Pop systems LP1 and LP2 without light-curing showed a significant (p<0.05) decrease in the amount (median) of ”continuous margin” in % of total margin length in dentin after TC:   location of margin CLB CSB APM EP LP2P+LC LP2P-LC LP2T+LC LP2T-LC LP1+LC LP1-LC enamel 97.5 96.0 97.8 96.3 92.4 100 97.7 96.9 99.9 100 dentin 100 100 99.3 91.9 96.8 77.4 91.6 73.7 90.2 64.7   The adhesive system Prompt L-Pop seems to be as effective as the other tested self etching adhesive systems, however, they should be light-cured before the application of the composite resin. This study was partly supported by ESPE, Kuraray and Merz Dental.