Effects of pathobiology of dentin/pulp complex to adhesive restorative techniques

研究了当前黏附树脂与比格犬牙本质楔形腔、箱形腔和磨牙的体内外微拉伸结合强度（MTBS），并通过扫描电镜（SEM）、透射电镜（TEM）、x射线衍射仪（XMA）和SIMS等观察树脂黏附的牙本质界面形态，以阐明牙本质/牙髓复合物的病理作用。Clearfil Liner Bond II （LBII）和Imperva Fluoro Bond （FB）在体内充填牙本质后，两种自蚀刻粘接剂体系的MTBS均高于30MPa，体内与体外MTBS无显著差异（p<0.05）。但充注后3周，两种体系的MTBS均显著下降，均小于20MPa， 3个月后MTBS相对稳定（约20MPa）。扫描电镜和透射电镜显示，充填后体内杂交层形成明显，但3个月后已看不到杂交层。与抗微管蛋白抗体反应的管状结构的存在抑制了树脂标签的形成。3个月后，SIMS显示氟化物离子在体内渗透到与FB结合的牙本质下。此外，我们在体外精确检测了龋病对树脂-牙本质结合的影响，发现单键（Single bond， SB）对正常牙本质的MTBS在40MPa以上最高，但SB对龋病牙本质的MTBS明显低于正常牙本质。SB、LB、FB对龋感染牙本质的MTBS均小于20MPa，但树脂可以部分包埋龋菌，提示粘接树脂对龋感染牙本质进行密封修复的可能性。

We investigated the microtensile bond strengths (MTBS) of current adhesive resins to dentin wedge-shaped and box-form cavities of beagle dog canines and molars in vivo and in vitro, and observed the interfacial morphology of resin-bonded dentin by SEM, TEM, XMA and SIMS so as to clarify the effects of pathobilogy of dentin/pulp complex.After filling of Clearfil Liner Bond II (LBII) and Imperva Fluoro Bond (FB) to dentin in vivo, both self-etching adhesive systems could show high MTBS more than 30MPa, and there were no significant differences between the MTBS in vivo and in vitro (p<0.05). However, 3 weeks later after filling, the MTBS of both systems showed significant decrease less than 20MPa, and 3 months later the MTBS were relatively stable (about 20MPa). The SEM and TEM showed that the formation of hybrid layers in vivo was clear immediately after filling, but 3 months later, hybri layers could not be seen. The resin tag formation were inhibited by the presence of the tube-like structures which reacted with anti-tubulin antibody. SIMS showed the penetration of fluoride ions into the subsurface dentin bonded with FB in vivo 3 months later.Moreover, we examined the effects of caries to resin-dentin bonding in vitro precisely, and Single bond (SB) could show the highest MTBS to normal dentin more than 40MPa, but the MTBS of SB to caries-affected dentin was significantly lower than that to normal dentin. The MTBS of SB, LB, FB to caries-infected dentin were less than 20MPa, however, carious bacteria could be partially embeded with resins, and these results suggested the possibility of sealed restoration to caries-infected dentin with adhesive resins.