The validity of caries risk assessment in young adults with past caries experience using a screening Cariogram model without saliva tests.

OBJECTIVE: To evaluate the caries-predictive validity of a screening Cariogram model without saliva tests in Chinese young adults with past caries experience.

METHODS: Two-hundred and fifteen Chinese young adults seeking dental care were included in this observational study, with informed consent obtained. All participants were 18-29 years of age and with past caries experience. A caries risk assessment was made at baseline using a full-blown Cariogram model and a screening Cariogram model without saliva tests; this assessment included bacterial count, saliva secretion and buffer capacity. Participants were divided into five risk groups according to 'the chance of avoiding caries' expressed in Cariogram software with two models. Each participant was required to receive re-examination after 2 years and then the actual caries increment (ΔDMFS) was calculated. The correlation between ΔDMFS and the ratings of caries risk was analysed using Spearman rank correlation. Differences between the full-blown and screening models were expressed as area under the receiver-operating characteristics (ROC) curve (AUC).

RESULTS: One-hundred and ninety-two participants finished the 2-year follow-up study, after 23 dropped out. The mean 2-year caries increment was 0.67 ± 1.03. Both Cariogram models displayed a statistically significant relationship with caries development (P < 0.001): more new caries was found among those assessed with high risk compared with those assessed with low risk. No statistically significant difference of the AUC was found between the two Cariogram models (P > 0.05).

CONCLUSIONS: The Cariogram model without saliva tests does not significantly decrease the caries-predictive ability in young adults with a history of caries. This screening model is a potential tool for rapid caries risk assessment for such populations.