Objectives:
- assess agreement between the SAP test and levels of salivary MS
- to classify children into caries risk groups using the SAP test
- to assess the risk classification in terms of subsequent caries experience.
Methods: Following addition of saliva to the SAP test solution a change of 0.3 pH units or more over 30 minutes results in a discernable colour change and is classified as high risk, otherwise they are classified as low risk. A sub-sample of n=50 children was used to compare the SAP test against levels of salivary mutans streptocci (MS). The study design was based on a prospective cohort study. Stimulated saliva was collected from n=215 6-8 year old children attending South Australian School Dental Service clinics. Children were classified at baseline into risk status groups and resampled 6 monthly over a two-year period. Caries increment was based on data from routine recall examinations prior to saliva testing and at subsequent follow-up recall examinations.
Results: A comparison of the SAP test to risk status based on levels of salivary MS resulted in a kappa value of 0.66 indicating substantial agreement between the 2 parameters.
Of the 215 children followed n=73 had one or more carious lesions over the 2-year period. Assessment of status by risk status showed a sensitivity of 0.219 and a specificity of 0.866.
Conclusion:
While the SAP test had adequate specificity the low sensitivity may limit the application of the test as a predictor of caries risk.
Supported by the NHMRC.