齲齒原因的理論及晚近研究結果之論介

Theories and Recent Findings Concerning the Etiology of Dental Caries

徐奎望(Kwai-Wang Shyu)

《Journal of Medical Sciences》 3卷3期 (1980/01) Pp. 971-987

摘要

齲齒之原因說法甚多。除古時之說法不足採信外，自密勒氏發表其化學寄生蟲說後，研究者更多，至今齲齒原因之理論約有內生說、外生說和結構缺陷說三大類，其中以外生說中之酸說立歷史較久，且亦為大多數學者所接受，但其所涉及立因素極廣，如牙釉之成份與顯微結構，牙齒之形態，牙菌膜，口腔衛生，口腔細菌，食物及唾液等。這些因素在某種配合下使局部pH降至臨界度以下而引起牙釉之脫鈣，形成齲齒。其機轉極為複雜。近一二十年來之研究對牙菌膜立形成、成份及其中pH變化的機轉頗多發現。這些發現均有利於酸說之進一步驗證，但却反證了蟄合說的缺點。在細菌學方面雖亦有若干發現，但用疫苗防齲則前途尚不可樂觀。近來對於酸說的有關研究，多與牙菌膜有關，因其已被公認為齲齒之必要條件。其發生可由唾液蛋白的沉澱，多醣的合成及細菌的沉積而成。牙菌膜所導致之酸對釉之脫鈣作用，鹼和類膠體之影響，及再鈣化現象等發現均對酸說作了實質上的註釋。若干其他對齲齒的新發現為齲齒外層的釉質鈣化頗高，牙齒內部的反應和Jackson-Burch對齲齒分佈的理論等均有待進一步的研究證實。

並列摘要

There are many theories concerning the etiology of dental caries. Numerous reports on the mechanisms of caries initiation have been published since Miller's chemico-parasitic theory was claimed in the begining of this century. They may be classified into three categories as: endogeous theories, structural theories and exogenous theories. Among them, the acid decalcification theory of the last category is most popularly accepted. The factors involved in this theory are quite complicate including composition and microstructure of enamel, morphology of teeth, dental plaque, oral hygiene, oral bacterial flora, diet and saliva. These factors, under certain combination, decrease local pH below the critical level to decalcify enamel and to form caries through a very complicate mechanism. In the recent two decades, investingators concentrated their attention on the studies on the formation, composition and pH changes of dental plaque. Most of the findings support acid theory rather than proteolysis-chelation theory. Some of them are even definitely against other hypotheses. Bacteriological studies reveal some new evidences, however, caries prevention by vaccination is still in exploratory stage with problems waiting to be solved. Dental plaque, a prerequisite for caries, has been widely investigated. It may arise from salivary proteins precipted by enzyme attack, acid or by calcium followed by passive invasion by bacteria. The decalcification of enamel by plaque acid, the effects of alkali and colloids and remineralization have substantially enforced the theoratical foundation of acid theory. Other findings like the outer well calcified zone of caries, changes within the tooth possibly influencing caries and Burch-Jackson hypothesis of the irregular distribution of caries need further studies for confirmation.