Preclinical competency in scaling/root planing: comparing dental and dental hygiene student’s outcomes

Dental students in Zurich receive 8.5 hours of preclinical training in scaling/root planing. Dental hygiene students receive a multiple of this amount. This study was undertaken to assess the students’ acquired preclinical competencies and to what degree they may differ. 34 undergraduate dental students and 20 dental hygiene (DH) students from two different schools in Zurich were tasked with scaling/root planing a maxillary left canine, coated with black lacquer from the apex to ca. 5 mm above the cemento-enamel junction, after completing their preclinical periodontal instrumentation course. The students were allowed to use any instrument in their set (Gracey or universal curettes) for a 5-minute period. Positive (experienced DHs) and negative (laypeople) control groups performed the same task. After instrumentation, teeth were scanned and planimetrically assessed. The percentage of cleaned tooth surface was calculated and statistically analysed (Kruskal-Wallis rank sum test, Conover’s test for pairwise comparisons). The dental students achieved the highest median cleaning efficacy (80.6%), followed by the experienced DHs (65.3%), the DH students (62.0%) and the laypeople (26.7%). When split by schools, a significant difference in instrumentation efficacy by the student DHs was seen (p <0.001). Despite their limited instruction time, the dental students acquired preclinical scaling/root planing skills comparable to, or better than, DH students with more training time.