Assessing caries risk--using the Cariogram model

In trying to make a comprehensive caries risk profile for an individual, one faces a situation that several factors need to be considered and weighted together. Summarising these factors could be a complex process and to facilitate the practical application, a computer-based risk assessment model for caries, the Cariogram, was developed. The Cariogram program operates basically in such a way that information on a number of factors are collected about the patient, transferred to 'scores' and these scores then entered into the program. According to its built-in algorithm, the program evaluates the data and presents the summarised result expressed as one figure, a pie-diagram, illustrating the 'Chance of avoiding cavities' in the future. This thesis deals with the evaluation of the Cariogram model and, as a first step, it was important to investigate if the program was in line with how colleagues, dental students and dental hygienists would evaluate a set of cases. The first two studies (Paper I and II) confirmed that the 'opinion' on the risk profile of the risk assessment program was in line with the opinions of the majority of the responders in these groups. In the third study (Paper III), the Cariogram's assessments were tested against the "reality" for the first time. The model was used to assess risk for caries among children and to evaluate the program by comparing the caries risk assessments of the risk model with the actual caries increment of the children over a two-year period. The hypothesis was that the Cariogram should be able to sort the children into caries risk groups according to the actual caries increment and the results confirmed the theory. It was also demonstrated that the Cariogram assessed caries increment more accurately than any included single factor model. Following the evaluation of the program on the children, the aim of the fourth study (Paper IV) was to evaluate the model for risk assessment in a group of elderly individuals. Comparing the caries risk assessment of the program with the actual caries increment over a five-year period showed that the program was able to arrange this group of elderly individuals into risk groups that reflected the actual caries incidence. The aim of the fifth study was to compare the risk profiles of the children with the risk profiles of the elderly. The evaluation of caries risk among the children showed that 3% was considered having very high caries risk, while 50% appeared in the low risk group. The corresponding values for the group of elderly individuals were 26% and 2%. Overall, the risk for caries, as assessed by the Cariogram, was twice as high for the elderly as for the children (V). The present thesis also tries to explore the concept of risk, the terminology and definitions related to risk, risk management and risk assessment in dentistry.