[A comparative study of the evolution of caries in mentally retarded subjects of 5 years' duration]

To study the evolution of caries in two groups of mentally retarded individuals.

Longitudinal, prospective, non randomized study, with a five-years follow-up period, with intervention and control groups.

Community trial. Primary health care centre in Martorell.

Mentally retarded individuals attending a workshop school (intervention group, N = 29) and living in a boarding school (control group, N = 25).

One group was on a program of prevention and treatment of caries, the other one received the usual care and acted as a control group.

The number of absent, filled and caries teeth were studied from 1992-1997. An analysis of the variance with repeated measures was carried out. The groups were comparable for most demographic characteristics and basal odontological parameters. While in the control group the number of caries increased (mean92 = 2.2; standard error [SE] = 0.5); mean97 = 3.3; SE = 0.5; p = 0.03) in the intervention group it did not change (mean92 = 1.8: SE = 0.4; mean97 = 1.7; SE = 0.2; p = 0.73). The variation over time was significantly different between the groups (p = 0.03). The mean of filled teeth increased in the intervention group (mean92 = 0.7; SE = 0.4; mean97 = 2.2; SE = 0.4; p < 0.0001) and it did not change in the control group (mean92 = 1.2; SE = 0.5; mean97 = 1.4; SE = 0.6; p = 0.48). There were statistical significant differences between the two groups in the variation over time (p = 0.017).

Preventive and curative odontological intervention in mentally retarded individuals can be useful to improve the evolution of caries.