Instrument effects on smoothness discrimination

Dental and dental hygiene faculty must select instruments to be used for root surface evaluation during scaling and root planing procedures. Because little information has been reported comparing the effectiveness of various instruments for this task, selection is based on subjective opinions. This study examined differences in the ability of 30 experienced and 32 inexperienced dental hygiene clinicians to differentiate degrees of surface smoothness using five different dental instruments. The relative smoothness test consisted of a set of ten paired abrasive strips of different or the same grit size. Repeated measures ANOVA revealed significance for both main effects, instrument used and experience level. All subjects made more correct assessments with the Williams probe, 3A explorer and Moffitt-MD probe than with the #17 explorer. There was no significant difference between the 3CH explorer and the other four instruments. Experienced clinicians scored significantly higher than students on the relative smoothness test. Instrument selection could affect the end products achieved by clinicians, as well as affecting validity and reliability of current clinical evaluation mechanisms.