This program evaluation examines the effectiveness of a school-based dental clinic. A repeated-measures design was used to longitudinally examine secondary data from participants (N = 293). Encounter intensity was developed to normalize data. Multivariate analysis of variance and Kruskal-Wallis test were used to investigate the effect of encounter intensity on the change in decay, restorations, and treatment urgency. A Pearson's correlation was used to measure the strengths of association. Encounter intensity had a statistically significant effect on change in decay (p = 0.005), restorations (p = 0.000), and treatment urgency (p = 0.001). As encounter intensity increased, there was a significant association with the decrease in decay (-0.167), increase in restorations (0.221), and reduction in referral urgency (-0.188). Incorporating dental care into a school-based health center resulted in improved oral health in underserved children while overcoming barriers that typically restrict access. The collaboration of school nurses with the school-based dental clinic was an important element for maximizing student access to dental care.