A Study on Microleakage of Class Ⅱ Composite Restorations
|School||Nanjing Medical University|
|Keywords||Composite resin Polymerization shrinkage Class Ⅱ cavity Microleakage Clinical Evaluation|
Composite resin due to aesthetics, environmental protection, with cohesiveness, etc., in clinical practice has been widely used, and replace amalgam trend. More perfect, scholars continue to study and explore and improved, including information on the volume of the composite resin polymerization shrinkage of the composite resin performance become a hot topic. Polymerization shrinkage of the composite resin is a the currently the composite resin widespread problem, and the marginal microleakage generated prosthesis. Due to the formation of microleakage after filling teeth, can lead to sensitivity, marginal discoloration, secondary caries, crown loose directly affect the composite resin restorative effects. The factors affecting the polymerization shrinkage of the composite resin for both the nature of the composite resin material and Clinical aspects, the former including the resin matrix, the filler type, elastic modulus, the resin fluidity, the latter including a cavity type, illumination mode, a cavity lining material and so on. Class Ⅱ cavity composite resin restoration difficult, when the the gingival edge in cemento-enamel junction root square cementum or dentin, gingival microleakage difficult to control. In this study, subjects choose in vitro experiments to observe the impact of different resins and different treatment of Class Ⅱ cavity gingival microleakage formation, and the observation and preliminary evaluation of the effect of the clinical application of the composite resin. Class Ⅱ cavity microleakage microleakage in vitro studies of the first part of the composite resin Class Ⅱ cavity experiment-methyl acrylic composite resin [Materials and Methods] freshly extracted 30 mandibular permanent molars, mesial occlusal II class slot-like hole shaped surface equipment, were randomly divided into 3 groups, respectively, after filling teeth compaction-type resin 3M P60, hybrid resin 3M Z250 and nano filler resin 3M Z350. Specimens by temperature cycling, magenta stain near and far to serial sections along the long axis of the stereomicroscope dye penetration was observed. Results] P60 group microleakage smaller Z350 group microleakage between the three groups, no significant differences (P gt; 0.05). [Conclusion] This 3 type resin filling Ⅱ class hole the gingival wall cementum - dentin edge microleakage was no significant difference. Experimental composite resin matrix of two different types of Class Ⅱ cavity microleakage [Materials and Methods] freshly extracted 20 mandibular constant molar mesial occlusal surface preparedness II slot-like hole shaped, were randomly divided into 2 groups. dental resin 3M P60, respectively, after filling the new Silorane matrix posterior teeth resin of 3M P90 and traditional methyl acrylic. Specimens by the temperature cycle after filling fuchsin, near and far to serial sections observed under the stereomicroscope dye penetration. 【Results】 P90 group microleakage was significantly less than the P60 group (P lt; 0.05). [Conclusion] the application the Silorane base resin P90 Filling can reduce class Ⅱ cavity the gingival wall cementum - dentin marginal microleakage. Experiment three composite resin Preheat Class Ⅱ cavity microleakage [Materials and Methods] freshly extracted 20 mandibular permanent molars, mesial occlusal surface preparedness II slot-like hole-shaped, filled with light-curing dental resin 3M P60, filling resin divided into 2 groups: direct filling resin electric oven preheat resin to 45 ℃ and 16 ℃ at room temperature. Specimens by the temperature cycle after filling fuchsin, near and far to serial sections observed under the stereomicroscope dye penetration. Results】 preheat resin group microleakage was significantly less than at room temperature resin group (P lt; 0.05). [Conclusion] The application of preheating resin filling can reduce class Ⅱ cavity gingival cementum - dentin edge microleakage. The initial evaluation of the second part of the composite resin clinical application [Materials and Methods] select clinical need composite resin restoration of teeth 117, 1 year after the repair of composite resin, a clinical review to assess the the composite resin clinical restorative effects, based on the modified USPHS criteria . [Results] 106 review teeth, the two repair failed four slight edge coloring, repair more satisfied, no secondary caries. [Conclusion] short-term repair of composite resin better.