Dental caries & Tooth decay l Oral pathology MCQs (multiple choice question) for dental students

Dental Caries

Dental caries can be defined as a microbial disease of the calcified tissues of tooth, characterized by demineralization of the inorganic portions and destruction of its organic structures. Dental caries is a complex, continuous, dynamic biological process of tooth decay, comprising of periods of progression alternating with periods of arrest or even partial repair. It has neither any dramatic or easily recognizable starting point, nor any end point, unless that is regarded as an acute pulpitis resulting in tooth extraction.

The periods of disease activity in dental caries vary widely in their duration and intensity between different population groups, between different individuals and within a single patient at different ages or even throughout the day. Even within a single mouth, individual sites of each tooth vary greatly in their susceptibility.

Like any other infectious disease the progress of dental caries depends upon a constantly changing balance between the nature and intensity of the injurious stimulus on one hand, and the nature and quality of the host’s biological responses on the other, many factors influence this balance. The initiation of a carious lesion at a given tooth surface, be it enamel of the crown or cementum of the exposed root surface, is customarily explained as a series of physicochemical phenomena, in which acids produced

by the fermentation of carbohydrates by the plaque bacteria, produce subsurface demineralization of the tooth enamel, and this is considered as the earliest manifestation of caries progression.

Dental caries has been recognized throughout history and exists around the world with variable frequency. The epidemiological studies on dental caries have been very useful in the determination of the need for, and effectiveness of, the dental treatments.

The most common epidemiological measure of dental caries is the DMF (diseased missing or filled) index; this is a measure of the number of teeth that are diseased, missing or filled. DMF may be reported as the number of teeth (DMFT) or surface affected (DMFS). These measures are cumulative because they represent the total number of extractions and restorations in a mouth, in addition to the number of teeth having active caries and the number of their surfaces involved.

The pathophysiology of dental caries is a very complex one and it cannot be explained in terms of a single event or observation. For this purpose the process of dental caries is often explained with the help of some theories, which are as follows.