The aim of the study was in vitro assessment of shear bond strength and micro-leakage after application of total-etch and self-etch adhesive systems.Materials and Methods: Four adhesive systems were chosen for assessment of adhesion performance: Contax (DMG, GmbH), Bond Force (Tokuyama Dental Corp. Japan Mfr), Te-Econom Bond (Ivoclar Vivadent, Liechtenstein) and Swisstec SL Bond (Coltene, Switzerland). The assessment of bond strength was performed on 20 tooth samples, which were prepared in accordance with the UltraTest technique for shear bond strength (SBS) estimation. The test was conducted at a crosshead speed of 1.0 mm/min and results were fixed in kilograms. The assessment of SBS was performed on enamel and dentin separately. Microleakage assessment of self-etch and total-etch adhesive systems was performed on 20 extracted non-carious upper human premolars with immersion in 1% methylene blue solution after thermocycling.Results: Good SBS results and microleakage values on the dentin substrate were obtained after application of the Contax self-etch bonding agent. But the values of bond strength to enamel and the extent of dye penetration within the composite-enamel interface were still better with the total-etch approach. (Int J Biomed. 2016; 6(4):283-286.)

The aim of the present study was to assess the side effect of an aluminum chloride hemostatic agent on adhesion strength and microleakage of composite resin restorations bonded with the one-bottle total-etch adhesive system. Methods: We prepared 10 human tooth samples (extracted premolars for orthodontic purposes) in accordance with the Ultratest technique for the assessment of shear bond strength (SBS), and another 10 human tooth samples for microleakage assessment. The SBS tooth samples (n=10) were subjected to the two following tests: In Test 1, before traditional adhesive protocol, the aluminum chloride hemostatic agent was rubbed into a surface dentin for 60 sec with the help of a metal dentoinfusor tip and washed with distilled water. In Test 2, just traditional wet bonding was performed. In the group of teeth (n=10) for microleakage assessment, we prepared two round artificial cavities of similar size (3 mm in diameter, 1 mm deep) in each tooth sample on the proximal surfaces with half in enamel and another half in root dentin. All created cavities (n=20) were divided into two subgroups. In cavities of Subgroup 1 (n=10), the adhesive protocol and filling with composite resin were performed after preliminary rubbing-in of the hemostatic agent. In Subgroup 2 (n=10), cavities were merely restored according to the rules for applying the one-bottle total-etch adhesive system. Assessment of microleakage was performed at the enamel margin and dentin margin. Scanning electron microscopy was used to evaluate the microstructure morphology of a hybrid layer, formed without the side effect of a hemostatic agent and after application of it. Results: The average score of SBS was 7.42±3.5 kg in Test 2 and 3.87±2.45 kg in Test 1. Therefore, the side effect of the aluminum chloride hemostatic agent was detrimental to the bond strength of the composite resin to human dentin and significantly decreased the quality of adhesion by 1.92 times (P<0.05). The average scores of dye penetration through the enamel-composite microgap in both subgroups were low (0.5±0.52 CU in Subgroup 1 and 0.3±0.48 CU in Subgroup 2) and had no significant difference (P>0.05). However, the visual analysis of the dentin-composite junction of sectioned tooth samples demonstrated 2.1 times more microleakage in Subgroup 1 (1.7±0.95 CU) than in Subgroup 2 (0.8±0.79 CU), but the difference was not significant (P>0.05). In view of clinical situations with no possibility to escape the application of a hemostatic agent in cases of possible capillary hemorrhage and crevicular fluid leakage, it could be wise before running an adhesive protocol to cut off the portion of surface dentin that was exposed to an aluminum chloride hemostatic agent side effect.