Relationship between root caries and coronal decay.

The relationship between caries on root surfaces and untreated coronal lesions was analyzed. A representative sample of 5028 persons was examined, their mean ages being 47.3 years for men and 47.7 for women. Poor dental health on root surfaces was associated with poor dental health in the coronal areas of the teeth. Subjects with root caries had fewer teeth and fewer fillings, more retained roots and more teeth with untreated coronal decay than did people with no root caries. Compared with the subjects without untreated coronal decay, those with from one to three decayed coronal surfaces showed an odds ratio of 4.5 of having caries on root surfaces. This ratio was 10.1 for the subjects who had more than three decayed coronal surfaces. It was concluded that factors related to the occurrence of decay are of a similar type whether caries is situated on root surfaces or in the coronal areas of the teeth, and therefore the prevention of caries in both sites may be accomplished by similar means.