Nagaoka S, Miyazaki Y, Liu H J, Iwamoto Y, Kitano M, Kawagoe M
Department of Operative Dentistry and Endodontology, Kagoshima University Dental School, Japan.
J Endod. 1995 Feb;21(2):70-3. doi: 10.1016/S0099-2399(06)81098-8.
The difference in resistance to bacterial invasion into the dentinal tubules between vital and nonvital teeth has not been determined. This study was conducted to clarify the effect of vital pulp on bacterial invasion into the dentinal tubules. The specimens were 19 intact pairs of bilateral upper third molars of 19 healthy, young adult male volunteers. In each case, 30 or 150 days before extraction, pulpectomies and root canal fillings were carried out unilaterally and a class V cavity involving the dentin was made on the palatal surface of both the pulpectomized tooth and the nonpulpectomized opposite tooth. The cavities were left unprotected to expose them to oral flora until the extractions were done, and the extracted teeth were examined histologically. When extraction followed 150-day exposure to the oral flora, there was a statistically significant difference in the bacterial invasion rate between the vital and nonvital teeth. It was postulated that vital teeth were much more resistant to bacterial invasion into the dentinal tubules than were nonvital teeth, thereby suggesting that the vital pulp plays some important role in this process.
活髓牙与死髓牙在抵抗细菌侵入牙本质小管方面的差异尚未确定。本研究旨在阐明活髓对细菌侵入牙本质小管的影响。标本取自19名健康年轻成年男性志愿者的19对完整的双侧上颌第三磨牙。在每种情况下，拔牙前30天或150天，对一侧牙齿进行牙髓摘除术和根管充填，并在牙髓摘除的牙齿和未进行牙髓摘除的对侧牙齿的腭面制备一个累及牙本质的V类洞。这些洞不做保护，使其暴露于口腔菌群中，直至拔牙，然后对拔除的牙齿进行组织学检查。当暴露于口腔菌群150天后拔牙时，活髓牙和死髓牙的细菌侵入率存在统计学上的显著差异。据推测，活髓牙比死髓牙对细菌侵入牙本质小管的抵抗力要强得多，这表明活髓在此过程中发挥了一些重要作用。
