纳米复合树脂（FiltekTM Z350）与犬牙髓组织的生物相容性**☆

背景：复合树脂无机填料的纳米化，使材料的机械性能得以明显改善，但其对牙髓组织的影响目前尚不清楚。目的：采用组织学方法评价纳米复合树脂（FiltekTM Z350）与犬牙髓组织的生物相容性。设计、时间及地点：随机对照动物实验，于2007-04/2008-04在解放军南京军区福州总医院动物实验中心完成。材料：选择3只成年雄性Beagle 犬，共60颗健康牙。方法：将犬牙人工制备颊面近髓V类深窝洞模型，将窝洞随机分为4组，分别用FiltekTM Z350、Dyract-AP复合体、TPH复合树脂及玻璃离子水门汀充填，充填前各组均使用可乐丽菲露SE BOND自酸蚀粘结系统处理。以未备洞的余留健康牙作为正常空白对照。主要观察指标：对各组样本牙的牙髓状态进行组织学评价，并测量所有样本的洞底剩余牙本质厚度。结果：术后7 d，大部分样本的牙髓组织均出现轻度炎症反应；术后30及90 d，除TPH复合树脂组外其余各组大部分样本的牙髓组织恢复正常，TPH复合树脂组仍有部分样本存在牙本质细胞层结构紊乱，其“组织结构紊乱”指标的评级高于其他组 (P < 0.05)。各组的平均剩余牙本质厚度无显著差别（P > 0.05）。 结论：该实验条件下，FiltekTM Z350纳米复合树脂的生物相容性和Dyract-AP复合体及玻璃离子水门汀相似，优于TPH树脂。

Biocompatibility of FiltekTM Z350 resin with dental pulp tissues of beagle dogs

Abstract BACKGROUND: Nano-size inorganic filling greatly improves mechanic characteristic of composite resin. However, its effects on pulp tissue remain unclear.OBJECTIVE: To evaluate the biocompatibility of FiltekTM Z350 nano-composite resin on dog pulp tissue by means of histology observation.DESIGN, TIME AND SETTING: Randomized control animal experiment was performed at the animal experiment center of Fuzhou General Hospital, Nanjing Military Area Command of Chinese PLA from April 2007 to April 2008.MATERIALS: Sixty healthy teeth from three adult male beagle dogs were recruited in this study.METHODS: Buccal Class V deep cavities were prepared in beagle dogs, which were then divided into four groups at random. FiltekTM Z350 resin, Dyract AP compomer and TPH resin were used to restore the cavities in three testing groups and glass ionomer cement was used as control. All cavities were treated with Clearfil SE BOND before filling. Intact healthy teeth were used as blank control. MAIN OUTCOME MEASURES: The pulp condition of each tooth was studied histologically. The remaining dentine thickness of each cavity was measured.RESULTS: After 7 days, mild inflammatory response was observed in most of the specimens. After 30 and 90 days, normal histological characteristics were observed in almost all specimens except TPH resin group. The histological structure disturbance of dentin cell layer emerged in some specimens of TPH group, which was higher than other testing groups (P < 0.05). There were no significant differences on remaining dentine thickness between these groups (P > 0.05).CONCLUSION: FiltekTM Z350 nano-composite resin has similar biocompatibility as Dyract AP compomer and glass ionomer cement, better than TPH resin.