구치부 제2급 와동에서 고흐름성 복합레진을 이용한 적층 충전술식의 미세누출에 미치는 영향 = THE EFFECT OF SANDWICH TECHNIQUE USING FLOWABLE COMPOSITE RESIN BASE ON THE MICROLEAKAGEIN CLASS Ⅱ CAVITIES OF MOLAR

다국어 초록 (Multilingual Abstract)

The aim of this study was to evaluate the marginal adaptation of direct class Ⅱ sandwich restoration with packable composites(P-60), resin modified glass ionomer cement(Fuji-Ⅱ LC), flowable compomer(Dyract Flow), flowable composites(Filtek Flow) in comparison with total bond restorations. In addition, for sandwich restorations, influence of different sandwich techniques was also evaluated.
Large butt-joint box typed class Ⅱ cavities with cervical margins 1mm below the cemento-enamel junction were cut into 70 extracted human molars. The cavities(7 groups, n=10) were filled using a closed/open sandwich restoration or total bond restoration technique with materials according to the manufacturer' s recommendation using the single component bonding agent for each system. Teeth were thermocycled 500 times between 5℃ and 55℃ with 30-second dwell time. The teeth were then coated with nail polish 1mm short of the restoration. placed in 2% methylene blue for 24 hours. and sectioned with diamond wheel. Sections were examined with a stereoscope ti determine the extent of microleakage. Dentine / Cementum margins were analyzed for microleakage on scale of 0(no leakage) to 4(entire axial wall) and interface between materials, to determine whether there were statistically significant differences among the seven groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Dunn s Method.
The results were as follows;
1. All groups showed some microleakage in cervical portion. But there were no microleakage in interface between materials.
2. Closed sandwich restorations with Fuji-Ⅱ LC and Filtek Flow had significantly lower leakage rating than total restorations with only P-60. However, open sandwich restorations with Dyract Flow showed significantly higher (P<0.05).
3. Closed sandwich restorations had significantly lower leakage rating than total restorations. However open sandwich restoration s showed significantly higher (P<0.05).
4. Sandwich restorations with Fuji-Ⅱ LC were lower leakage than only P-60, Filtek Flow, Dyract Flow. But there were no statistically differences among the materials.
From the results above, it could be concluded, c losed sandwich restorations was effective in reducing microleakage of class Ⅱ restorations. The best results showing the least microleakage were for the closed sandwich technique with Fuji-Ⅱ LC and Filtek Flow.