Figure 2. Survival analyses for the incidence of primary and secondary caries, focused on a combination of specific cariogenic bacteria level and compliance with the preventive program using the Kaplan–Meier and log-rank tests.

SM level: high (higher than 1 × 10⁶ CFU/ml); low (1 × 10⁶ CFU/ml or lower). LB level: high (1 × 10⁴ CFU/ml or higher); low (lower than 1 × 10⁴ CFU/ml). Each patient’s compliance with the preventive program was categorized as follows: good (regular visits + sometimes delayed visits); poor (irregular visits + emergency visits only). *Statistically significant at a level of p < 0.05.