다양한 벌크필 복합레진의 중합수축 응력 비교 = Comparison of Polymerization Shrinkage Stress Among Various Bulk-fill Resin Composites

다국어 초록 (Multilingual Abstract)

Comparison of Polymerization Shrinkage Stress Among Various Bulk-fill Resin Composites Somin Lee, D.D.S. Advisor : Prof. Tae-young Park, D.D.S., MSD Department of Dentistry Graduate School of Chosun University Polymerization shrinkage stress in composite resins can lead to clinical failures such as microleakage, secondary caries, and postoperative sensitivity. To minimize this stress and reduce clinical procedure times, bulk-fill composite resins were introduced. However, it remains unclear whether the compositional and structural modifications of bulk-fill resins lead to continuous stress relaxation over time. Therefore, this study aimed to evaluate and compare the polymerization shrinkage stress of eight bulk-fill composite resins over time. The materials tested were Any-Com Bulk (AB; MediClus, Cheongju, Korea), Beautifil Bulk Flowable (BB; SHOFU, Kyoto, Japan), Denfill Bulk Flow (DB; Vericom, Chuncheon, Korea), EsFlow PLUS Bulk Fill (EB; Spident, Incheon, Korea), G-aenial Bulk Injectable (GB; GC, Tokyo, Japan), SDR Flow+ Bulk Fill Flowable (SDR; Dentsply Sirona, York, PA, USA), SHOOT Bulkfill (SHB; Healings, Gwangju, Korea), and Tetric N-Flow Bulk-Fill (TB; Ivoclar, Schaan, Liechtenstein). Ten specimens were prepared per group using 3D-printed acrylic molds (outer diameter: 10 mm, inner diameter: 7 mm, height: 4 mm) attached to a strain gauge to measure polymerization shrinkage strain. The resin was applied into the mold and light-cured for 40 seconds using a light-curing unit (B&Lite S, B&L Biotech, Ansan, Korea; 1,200 mW/cm2) with the tip positioned perpendicularly to the top surface of the mold at a distance of 1 mm. Polymerization shrinkage strain was recorded every second for 800 seconds from the onset of light curing, and the obtained data were converted into polymerization shrinkage stress (MPa) using Hooke's law. Statistical analysis was performed using SPSS version 29.0, employing one-way ANOVA followed by Tukey's HSD test to compare the eight groups at 100-second intervals (α = 0.05). All tested groups exhibited a transient initial expansion immediately after light curing, followed by shrinkage that gradually reached a plateau over time, with TB showing the lowest polymerization shrinkage stress (0.153 ± 0.114 MPa) and BB the highest (0.649 ± 0.352 MPa) at 800 seconds. The one-way ANOVA revealed statistically significant differences in shrinkage stress among the eight bulk-fill composite resins at every 100-second interval throughout the 800-second period (p < 0.05). Understanding the distinct polymerization shrinkage stress characteristics of each bulk-fill composite resin is essential for clinicians to make strategic material selections in clinical practice.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 실험재료 및 방법 2
• Ⅲ. 실험결과 8
• Ⅳ. 총괄 및 고안 11
• Ⅴ. 결론 15
• VI. 참고 문헌 16