全酸蚀刻作用对家兔牙髓组织影响的相关因素研究

Relational factors research of total-etching on rabbit pulp tissues

目的观察家兔牙髓对于全酸蚀刻作用的组织病理学反应,探讨全酸蚀刻对活体牙髓的相关影响因素。方法选取88颗兔齿,在切牙唇面牙颈部备Ⅴ类洞,随机分为4组,于各洞壁进行酸蚀、涂抹黏结剂：A组酸蚀15s,使用Prime＆Bond NT黏结剂;B组酸蚀15 s,使用Single Bond 2黏结剂;C组酸蚀30 s,使用Prime＆Bond NT黏结剂;D组酸蚀30 s,使用Single Bond 2黏结剂。以上各组均使用光固化复合树脂分层固化、充填,并分别于1天、3天、7天后拔除实验牙进行常规组织病理脱矿切片,HE染色后显微镜下盲法评价牙髓组织的反应。结果①使用同种黏结剂时,酸蚀时间15 s各组与30 s各组中炎症细胞反应、组织结构紊乱评分结果差异无显著性（P〉0.05）;②使用不同种黏结剂时,7天后拔除实验牙中的Single Bond 2 15 s组炎症细胞反应评定结果高于Prime＆Bond NT30 s组（P〈0.05）,其余各组各评定指标均未见显著差别（P〉0.05）;③当剩余牙本质厚度小于500μm时较大于500μm时牙髓炎症细胞反应显著,且随着剩余牙本质厚度减小炎症细胞反应、组织结构紊乱程度加重。结论①15~30 s内,酸蚀时间对活体牙髓组织无明显影响;②黏结剂的种类可能对活体牙髓产生一定影响,且SingleBond 2对牙髓组织的病理刺激略大于Prime＆Bond NT;③剩余牙本质厚度对牙髓组织产生一定影响,在临床上尽量保证剩余牙本质厚度大于500μm是非常必要的。

Objective To observe the rabbit-pulpal response to histopathology capping with total-etching and to study the relational factors influencing the living pulp resulted by total-etching.Methods Eighty-eight sound teeth of rabbit were selected,which were required ClassⅤ restorations at buccal surfaces and were divided into 4 groups at random：in group A,the cavity walls were conditioned with 35 %phosphoric acid for 15 s and the dentin adhesive system Prime Bond NT was applied;in group B,the cavity walls were conditioned with 35 % phosphoric acid for 15 s and the dentin adhesive system Single Bond 2 was applied：in group C,the cavity walls were conditioned with 35%phosphoric acid for 30 s and the dentin adhesive system Prime Bond NT was applied;in group D,the cavity walls were conditioned with 35 %phosphoric acid for 15 s and the dentin adhesive system Single Bond 2 was applied.The cavities in every groups were restored with light-cured Spectrum TPH composite resin.The teeth were extracted at 1 d,3 d,7 d and prepared for normal histologic techniques.Serial sections were measured for remaining dentin thickness and stained with HE for microscopic assessment of pulp issue blindly.Results ①Whenusing the same dentin adhesive agents,there was no significant influence to the living pulps between 15 s-etching-time groups and 30 s-etching-time groups（P0.05）.②When using the different dentin adhesive agents and extracted teeth after 7 days,evaluation of inflammatory-cell-response in group Single Bond 2 15 s was higher than in group PrimeBond NT 30 s（P0.05）and there was no marked result in tissue-structure-disorder（P0.05）.There was no evident difference in other groups（P0.05）.③There were more significant pulpal inflammation when RDT was under 500 μm than beyond 500 μm,which aggravated when RDT decreased.Conclusion ①It has no notable influences to living pulps for changing etching time and from 15 to 30 s is available.②The ingredients of the dentin adhesive agent may affect the pathological responses to pulps in some ways and Single Bond is more stimulating than PrimeBond NT.③ RDT can give an affect to tissues to some exent,so a RDT of 0.5 mm or greater is necessary in clinic.