**1. Introduction**

240 Contemporary Approach to Dental Caries

Wong, TY., Preston, LA. & Schiller, NL. (2000). Alginate lyase: Review of major sources and

ISSN 0066-4227

enzyme characteristics, structure-function analysis, biological roles, and applications. *Annual Review of Microbiology*, Vol. 54, (October, 2000), pp. 289-340,

> Tooth caries, which is regarded as a social disease in many countries, affects 100% of population. For many years both high prevalence and increasing intensity of caries have inspired researchers to find effective methods of fighting the disease. The quest for caries prevention methods has led to more and more widespread sealing of fissures of lateral teeth (premolars and molars), where sealants - thanks to mechanical protection from influence of oral cavity environment, thanks to reduction of retention sites and of bacterial flora in fissures - have effectively limited the development of carious disease.

> Currently known methods of caries prevention can be deemed effective to the degree justifying their widespread application. Despite this fact, dentists across the world devote most of their working time to elimination of caries's results.

> In permanent dentition, tooth decay most frequently affects masticatory surfaces of molars and, as numerous studies report, very soon after their eruption 2/3 of cavities are observed just there. This is confirmed by epidemiological studies, which have been conducted in Poland since 1987 under WHO supervision (29). The studies reveal that at the end of 1970s, over 50% of permanent molars were affected by caries in children aged 6-7 years, whereas children aged 9 years had almost all first permanent molars with carious cavities or filled. In the age group 13-15 years, the percentage of teeth affected by caries reached 80%, though occlusal surfaces of teeth constitute only 12.5% of all surfaces of teeth in the oral cavity. The aforementioned epidemiological studies indicate the importance of activities towards caries prevention on masticatory surfaces.
