Adriaens P A, Claeys G W, De Boever J A
Scanning Microsc. 1987 Jun;1(2):671-80.
This study was performed to gain better insight into the mechanisms involved in carious destruction of human dentin by Streptococcus mutans. In particular, bacterial colonization of dentin surfaces and bacterial invasion in dentin were studied. Streptococcus mutans (S. mutans), strain NCTC 10449, was grown on sterile dentin blocks in a 10% CO2 atmosphere at 37 degrees C. After 72, 120, 144 and 288 h of incubation the specimens were processed for scanning electron microscopic examination. The colonization of the dentinal surface progressed slowly and was nearly complete after 288 h. Invasion of S. mutans into the dentinal tubules was found occasionally and was limited to the initial 5 micron of the tubular lumen. The acid metabolites produced by S. mutans, caused lesions of the dentinal structures in the close proximity of the bacteria. From the results of this in vitro study it appears that carious destruction of exposed dentinal surfaces by S. mutans mainly occurs at the exposed dentin after it has been colonized by bacteria. Destruction of the deeper dentinal layers by bacteria invading the dentinal tubules may play a less important role. However, in the few cases where S. mutans invaded the dentinal tubules, rapid destruction of the peritubular dentin sheath occurred. In addition, the possibility remains that acid metabolites produced by S. mutans diffuse into the dentinal tubules and cause tissue damage in the deeper parts of the dentin.
本研究旨在更深入地了解变形链球菌对人类牙本质龋损破坏的机制。特别对牙本质表面的细菌定植和细菌侵入牙本质的情况进行了研究。变形链球菌（S. mutans）NCTC 10449菌株在含有10%二氧化碳的无菌牙本质块上于37℃培养。培养72、120、144和288小时后，对标本进行扫描电子显微镜检查。牙本质表面的定植进展缓慢，288小时后几乎完成。偶尔发现变形链球菌侵入牙本质小管，且仅限于小管腔最初的5微米。变形链球菌产生的酸性代谢产物在细菌附近导致牙本质结构的病变。从这项体外研究的结果来看，变形链球菌对暴露牙本质表面的龋损破坏主要发生在细菌定植后的暴露牙本质处。细菌侵入牙本质小管对更深层牙本质层的破坏可能起的作用较小。然而，在少数变形链球菌侵入牙本质小管的情况下，管周牙本质鞘会迅速破坏。此外，变形链球菌产生的酸性代谢产物仍有可能扩散到牙本质小管中，并在牙本质较深部位造成组织损伤。
