Comparative Evaluation of Periodontal Instruments for the Detection of Subgingival Calculus

Background/Objectives: This study compared the capabilities of four periodontal assessment instruments (CP11 probe, WHO probe, explorer, and #11/12 explorer) to detect subgingival calculus and assess calculus morphology when used by dental hygienists, with a focus on their clinical and educational relevance. Methods: Typodont models with artificially placed subgingival calculus of various shapes were used by 27 dental hygienists to assess the presence and morphology of calculus using each instrument, and a questionnaire on the usability of the #11/12 explorer was completed. Results: Subgingival calculus detection rates did not significantly differ between instruments in either entire mandibular jaw model or individual anterior and posterior regions. Calculus morphology detection did not differ for the entire model or anterior regions but did significantly differ in posterior regions, with the #11/12 explorer showing the highest detection accuracy. Morphology-dependent differences were observed between CP-11 and WHO probes. Qualitative analysis of free-text responses regarding #11/12 explorer use with KH Coder identified clusters related to tactile perception, operability, and experiential/educational aspects. Conclusions: Although the overall calculus detection performance did not significantly differ among the instruments, the #11/12 explorer demonstrated higher detection accuracy in the posterior regions and was favorably rated in terms of tactile feedback and operability. These findings suggest that the #11/12 explorer may be a useful instrument for subgingival calculus assessment and may have educational value for developing tactile assessment skills.