Interincisal distance and patient-reported tolerability of adjunctive caries detection methods: a cross-sectional questionnaire study

Aims: To evaluate patient-reported comfort, gag reflex, and examination time across visual-tactile and adjunctive caries detection approaches, and to determine whether these outcomes differ according to interincisal distance.Methods: Adults aged 18-60 years attending routine visits between November 5, 2025 and February 5, 2026 underwent visual-tactile examination using the International Caries Detection and Assessment System II and 4 adjunctive methods: DIAGNOdent Pen (KaVo Dental GmbH, Biberach, Germany), QrayPen (AIOBIO, Seoul, Republic of Korea), QrayCam Pro (AIOBIO, Seoul, Republic of Korea), and iTero Element 5D (Align Technology, San Jose, CA, USA). Visual-tactile examination was performed first; adjunctive methods were applied in 2 counterbalanced randomized sequences. Maximum interincisal distance was categorized as ≤3,5 cm, 3,6-5,0 cm, or >5,0 cm. Comfort and gag reflex were rated on 3-point ordinal scales and quadrant examination time was categorized into 4 levels. Nonparametric tests were used.Results: Ninety-six participants were analyzed (mean age, 22,4 years). Outcomes did not differ by randomized sequence. Lower interincisal distance was associated with lower comfort and higher gag reflex for all adjunctive methods (all P ≤ ,01) and with longer time categories for QrayCam Pro, QrayPen, iTero Element 5D, and DIAGNOdent Pen (all P ≤ ,01). Across methods, comfort, gag reflex, and time differed (all P < ,001). QrayCam Pro was most frequently preferred (52/96; 54,2%), whereas iTero Element 5D was not selected.Conclusion: Interincisal distance is a practical indicator of patient tolerability and workflow impact when selecting adjunctive caries detection approaches.