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A study on fissure penetration and microleakage of sealants after preparations of occlusal pits and fissures

 A study on fissure penetration and microleakage of sealants after preparations of occlusal pits and fissures 
Issue Date
 Graduate School, Yonsei University 
Dept. of Dentistry/석사
[한글] 치면열구 전색제의 교합면 우식 억제 효과는 이미 잘 알려져 있는 바이다. 이런 전색제의 유지력을 극대화시키기 위한 여러 시도들이 이루어져 왔는데 그중 하나가 전색제의 도포전 교합면 열구의 처리방법이다. 본 실험에서는 산부식 방법만을 사용한 경우, rotary instrument를 이용한 기계적 삭제 방법 및 air abrasion을 사용한 방법등 세 가지 조건으로 나누어 filled sealant 와 unfilled sealant를 도포한 후 이들 전색제의 열구 침투도와 미세누출 정도를 측정 평가하였다. 최근에 교정을 목적으로 발거된 72개의 건전한 소구치를 각각 24개씩 세 군으로 나누어 분배한 후 위의 세 가지 방법으로 처리하였다. 세 군의 치아를 각각 12개씩 filled sealant 와 unfilled sealant로 도포한 후 총 여섯 군의 치아를 5■와 55■의 수조에 번갈아 20초씩 1000회의 열순환을 실시하고 5% methylene blue용액에 24시간 보관한 뒤 각각의 치아를 근심 소와와 원심 소와에서 협설 방향으로 절단하여 144개의 절단면을 얻었다. 이렇게 얻어진 시편을 입체 현미경 (Olympus, Japan)을 통하여 영상을 컴퓨터에 입력한 후 화상 분석 프로그램 (Image-Pro plus ver 3.0)을 이용하여 전색제 및 색소의 침투 깊이를 측정하고 비율을 계산하여 전색제의 열구침투도와 미세누출 정도를 평가하여 다음과 같은 결과를 얻었다. 1. bur를 이용하여 기계적 삭제를 시행한 군에서 통계학적으로 유의성 있게 치면열구 전색제의 열구침투도가 증가하였고 미세누출은 감소하였다. (P<0.05) 2. air abrasion방법으로 처리한 군이 산부식 방법만을 사용한 군보다 통계학적으로 유의성 있게 치면열구 전색제의 열구침투도가 높았다. (P<0.05) 3. 산부식 방법만을 사용한 군과 air abrasion방법으로 처리한 군 사이에서 미세누출은 유의 차가 없었다. (P>0.05) 4. 세 가지 방법으로 처리한 후 filled sealant 와 unfilled sealant를 도포한 경우 열구침투도와 미세누출은 통계학적인 유의 차가 없었다. (P>0.05)
[영문] Objective: Considering the importance of sealant integrity, the purposes of this study were as follows. 1. To compare the fissure penetration and microleakage of sealants after acid etching, bur preparation with acid etching and air abrasion preparation with acid etching. 2. To compare the fissure penetration and microleakage of filled and unfilled sealants using the same three preparation methods. Materials and Methods: Seventy-two freshly extracted human premolars for orthodontic purposes with no or minimal occlusal caries were assigned to six groups. In group 1 and 2, teeth were prepared using acid etching only. In group 3 and 4, the pits and fissures were opened with 1/4 round carbide bur in a high speed handpiece to an approximate diameter of the bur followed by acid etching. In group 5 and 6, teeth were air abraded using a high-velocity air microabrasion machine (Prep. StarR, Danville Inc.). The kinetic cavity preparation technique was performed, using the particle size of 50㎛ aluminum oxide and nozzle tip size of 0.15/80?. In group 1, 3 and 5, a filled sealant (Ultraseal XT plusR, Ultradent, U.S.A) was used with a drying agent (PrimadryR, Ultradent). In group 2, 4 and 6, teeth were sealed with an unfilled sealant (Teethmate F-1R, Kuraray, Japan). After application and curing of sealants, all teeth were thermo-cycled between 5℃ and 55℃ for 1200 cycles. And then, the teeth were dried and coated with two coats of nail varnish and then immersed in a 5% methylene blue solution for 24 hours. Each tooth was sectioned buccolingually parallel to their axes. These sections were examined under a stereo microscope and all images were computerized to evaluate the degree of fissure penetration and microleakage. Statistical analysis was completed using Duncan''s test and Tukey''s test. Results: 1. Superior results in both sealant penetration and microleakage were shown when the tooth surface was prepared by a bur (group 3 & 4). (P<0.05) 2. The sealant penetration rate was significantly higher in air abrasion groups (group 5 & 6) than acid etching groups (group 1 & 2). (P<0.05) 3. Acid etching only groups (group 1 & 2) and air abrasion groups(group 5 & 6) yielded similar results in microleakage. (P>0.05) 4. No statistically significant difference in the penetration and microleakage was found between filled and unfilled sealants. (P>0.05)
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2. 학위논문 > 2. College of Dentistry (치과대학) > 석사
Yonsei Authors
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