应用牙器官培养模型评价粘结剂的生物相容性

目的:应用大鼠全牙器官培养模型对两种牙科粘结剂进行生物相容性评价。方法:在新鲜拔除的4周龄SD大鼠切牙唇面制洞,随机分成3组:对照组(不涂粘结剂);AP组(涂Adper Prompt粘结剂)和PB组(涂Prime&Bond NT粘结剂),3组洞壁做相应处理后光照10 s后填入树脂,分别于术后即刻和体外全牙培养1周两个时间点,40 g/L多聚甲醛(PBS)固定,100 g/L甲酸脱矿,常规切片,HE染色进行组织学观察,并采集图像进行细胞计数及统计学分析。结果:术后即刻与对照组相比,PB组制洞部位下方的牙髓细胞发生聚集,AP组则表现为成牙本质细胞的细胞数减少,两种细胞均发生形态改变。术后培养1周时与对照组相比,AP组制洞部位下方的牙髓内牙髓细胞坏死,而PB组则表现为成牙本质细胞的细胞数目减少,两种细胞均发生形态改变。结论:两种牙科粘结剂均对牙髓组织有毒性作用,早期AP的毒性大于PB。

Biocompatibility assessment of two dental bonding agents with a rat tooth organ culture model

AIM: To assess the biocompatibility of two dental bonding agents by rat tooth organ culture model in vitro.METHODS: Cavities were prepared on labial surface of freshly extracted mandibular and maxillary incisors of 28-day old SD rat.The cavity walls were randomly conditionded with two dental bonding agents,Prime & Bond NT(PB) and Adper Prompt(AP),respectively.Non-conditioned walls served as control.After bonding,the cavities were filled with resin.The samples were maintained in sterile DMEM culture medium containing of fetal calf serum for one week.After culture,the tooth tissues were fixed in 10% formalin for 24h,followed by a demineralization process in 10% formic acid for 72 h and embedded in paraffin wax.Longitudinal sections of each tooth slice were cut with a microtome and stained with haematoxylin and eosin.Cell numbers within the dental pulp complex of each tooth slice were counted histomorphometrically at X 40 magnification.RESULTS: Immediately after cavity filling,cells in subodontoblast cell layer aggregated in PB treated group,while a loss of morphologically intact odontoblast cells was found in AP treated group.Morphological changes were observed within the dentine-pulp complex of both PB and AP groups.After seven days culture,necrotic pulp cells were observed in AP group.While numbers of odontoblast cells decreased in PB group.Both groups showed morphological changes.CONCLUSION: Prime & Bond NT and Adper Prompt have cytotoxicity to dental pulp,and AP is more cytotoxic than PB at early stage.