1. Mechanical and morphological evaluation of the bond – dentin interface in direct resin core build - up method Mariko Matsumoto Jiro Miura Fumio Takeshige Hirofumi Yatani

2. 牙五孝 第一組 Ting - Zhen Yu * 05 Yu - Sophie Chen * 18 Ting -Yu Chen * 41 Adviser : Meng - wei Li

3. This study was to evaluate the interfacial adhesion between resin and root canal dentin in the direct resin core build - up method in terms of microtensile bond strength and dentin micro morphology. The purpo se

4. Materials 16 caries - free human teeth distilled water composite resin curing light

5. Methods Dental caries remaining root and crown disappeared. Then root canal preparation was performed and root canal treatment.

6. using gutta stored in distilled water for 24 h.

7. Root canals were enlarged. IN EDTA solution. hypochlorite gel. Dual - cure bonding agent. The adhesive was then light - cured for 20 s.

8. filled with a dual - cure resin composite core material several times. Light exposure was performed for 40 s. All specimens were in water for 24 h,37 ˚c.

9. six slabs 1 mm × 1 mm thick for microtensile test. 6 1 mm × 1 mm

10. scanning electron microscopy ( SEM ) energy - dispersive X - ray spectrometry ( EDX ). Sectioned specimens were observed by ultra - high - voltage transmission electron microscopy.

13. The images of ultra-high voltage electron microscope. (A) conal bond–dentin intorerface. (B) apical bond–dentin interface scale bar ： 5µm.

14. The bond strength of root dentin decreased gradually from the coronal to apical side. The core material penetrated into dentinal tubules in the apical region.

15. Discussion and Conclusion The fracture mode on the coronal and apical sides differed. The micro bonding strength gradually decreases from the coronal side to the apical side of the root canal.

16. Is difficult to achieve polymerization and moisture control in the apicalportion of the root canal.

17. Resin surface is irradiated with sufficient light energy to ensure a high degree of polymerization Light energy is a unit that encompasses two factors

18. 8. 分配表 翻譯 : 余庭甄 (5) 陳羽柔 (18) 陳亭喻 (41) PPT: 余庭甄 陳亭喻 報告 : 余庭甄 陳亭喻

19. ~ T hank y ou for l isten ~