ABSTRACT
AIM: To evaluate the effect of surface moisture on dentinal tensile bond strength. MATERIALS AND METHODS: Forty freshly extracted caries free, unrestored human mandibular molars were selected. The occlusal surfaces of each tooth were ground to prepare flat dentin surfaces at a depth of 1.5 mm. Following acid etching with 37% phosphoric acid for 15 sec, they were randomly grouped, with ten specimens in each: Group I - Over wet, Group II - Blot dry, Group III- One second dry, Group IV- Over dry. Each group was treated with a single bond adhesive system (3M ESPE) as per manufacturer's instructions. Blocks or cylinders of composite resin were built up using Teflon mould and cured. Tensile bond strengths were tested using Instron universal testing machine. The results were statistically analyzed. RESULTS: The mean tensile bond strength values of group II, Blot dry was highest and statistically significant (P<0.001). CONCLUSION: After acid etching and rinsing blot drying provided consistently better bond strength.
ABSTRACT
This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface. V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15 s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15 s and rewet with Aqua-Prep F for 20 s). Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p 0.05). At the enamel-resin interface, group D showed the gap of 2 microm thickness, but group BD and DR showed close adaptation. In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.
Subject(s)
Humans , Dental Enamel , Methylene Blue , MolarABSTRACT
This study compared the dentin adhesion to composite resin according to air-dry, blot dry, application of rewetting agent on air-dry or blot dry dentin surface by microleakag test and SEM observation. For microleakage test, class V cavity preparations with dentinal margins were prepared on both buccal and lingual surfaces of 40 extracted human molars. For SEM observation, occlusal dentin of 20 extracted human molars were exposed. After etched the dentin, prepared teeth were randomly divided into four groups; D group: air dry for 10-15 sec., B group: blot dry with moist cotton pellet, D-R group: air dry and rewet with Aqua-Prep F for 20 sec., B-R group: blot dry and rewet with Aqua-Prep F for 20 sec. Treated cavities and surfaces were filled or constructed using One-Step adhesives and Aelitefil composite resins. Specimens were stored in distilled water for 24 hours. For microleakage test, the specimens were thermocycled and soaked into 2% methylene blue. The specimens were sectioned longitudinally and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis Test, Mann-Whitney and Wilcoxon signed ranked tests. For SEM observation, the specimens were bisectioned mesiodiatally. After decalcified and deproteinized, specimens were observed under SEM. The results of this study were as follows; 1. The microleakges on dentinal margin were the highest in D group compared with B group, D-R group, and B-R group(p<0.05). But there was no significant difference between B group, D-R group and B-R group. 2. D group showed gap and a few resin tags between dentin and composite resin. 3. B group, D-R group, and B-R groups showed close adaptation between dentin and composite resin. It showed that resin rags in B group were numerous and long, in D-R group were few and short, in B-R group were numerous and short or long. 4. Adhesive layer showed in D-R group (10 microm) and B-R group (3 microm) In conclusion, use of rewetting agent to dry dentin was efficient to dentin adhesion, also it did not provide reverse effect on blot dry dentin.
