Introduction: Fear of root canal treatment (RCT) may affect care seeking and treatment experience but is often summarized using anxiety scores. This study identified fear severity patterns and trigger-content profiles and examined associations with avoidance and negative experiences. Materials and Methods: In this single-center cross-sectional study, 219 of 247 adults scheduled for primary RCT were analyzed after 28 exclusions. Preoperative anxiety was measured using a 0–10 cm Visual Analog Scale for Anxiety (VAS-A). Hierarchical cluster analysis identified fear severity patterns, and latent class analysis identified trigger-content profiles among participants endorsing at least one trigger. Results: At least one trigger was endorsed by 75.8%; 21.9% had severe anxiety (VAS-A ≥ 7.0). Severe anxiety increased descriptively from 1.9% with no trigger to 54.3% with three or more triggers. Hierarchical clustering identified low-fear (n = 152) and high-fear (n = 67) patterns. In bivariate comparisons, high-fear membership was more common among women, participants postponing dental visits, and those with negative childhood or adult RCT experiences, and less common among regular dental attenders. Hierarchical multivariable logistic regression showed that female sex and negative adult RCT experience were associated with higher odds of high-fear pattern membership, whereas regular dental attendance was associated with lower odds; negative childhood RCT experience and postponement were not independently significant in the fully adjusted model. Latent class analysis yielded needle-focused (n = 38) and procedural (n = 128) profiles; the latter showed a broader trigger range, while VAS-A distributions were similar. Conclusions: Fear of RCT was heterogeneous. Assessing severity, triggers, and avoidance history may support individualized communication. The profiles require external validation before use.

Local cooling may supplement endodontic anesthesia, but its intrapulpal thermal effects remain incompletely characterized. This in vitro study compared peak intrapulpal temperature reduction (ΔT), recovery from the temperature minimum, and maximum cooling rate for gauze-wrapped ice, an Endo-Frost-cooled cotton pellet, and a direct ice stick across unprepared, 2 mm, and 4 mm cavity-preparation conditions. Ten extracted mandibular first molars received 10 applications per protocol and condition. Intrapulpal temperature was recorded every second with the roots in a 37.0 ± 0.1 °C water bath. Outcomes were analyzed using linear mixed-effects models. Protocol, preparation condition, and their interaction affected ΔT (all p < 0.001); estimated reductions increased with preparation depth and ranged from 3.67 to 5.06 °C for direct ice, 4.59 to 6.43 °C for gauze-wrapped ice, and 10.24 to 13.32 °C for the cooled pellet. Recovery to 50, 75, and 100% of the maximal drop showed significant protocol-by-condition interactions (all p ≤ 0.022). Gauze-wrapped ice had the shortest minimum-to-baseline recovery interval at every condition (all p < 0.001 versus the other protocols), whereas the cooled pellet had the highest pooled estimated maximum cooling rate. These findings do not establish clinical anesthetic efficacy or an isolated effect of remaining dentin thickness.

Introduction: Root canal treatment (RCT) fear may affect treatment-seeking behavior, cooperation, and experience, yet it is often evaluated through overall anxiety scores. This study profiled RCT fear by severity and trigger content and examined associations with dental avoidance and negative experiences. Materials and Methods: In this single-center cross-sectional study, 247 adults scheduled for primary RCT completed a questionnaire; 28 incomplete or internally inconsistent questionnaires were excluded, leaving 219 participants. The questionnaire assessed dental attendance, postponement, previous RCT, fear triggers, and personal, social, and media-related negative experiences. Preoperative anxiety was measured using a 0-10 cm Visual Analog Scale for Anxiety (VAS-A). Fear-severity profiles were identified by hierarchical cluster analysis, and trigger-content profiles by latent class analysis among participants reporting RCT fear. Results: RCT-related fear was reported by 75.8%, and 21.9% had severe dental anxiety (VAS-A ≥ 7.0). Severe anxiety increased from 1.9% among participants reporting no trigger to 54.3% among those reporting three or more triggers. Hierarchical clustering identified low-fear (n = 120) and high-fear (n = 99) profiles. The high-fear profile was more frequent among women, irregular dental attenders, those who postponed visits, and those with a negative adult RCT experience. Latent class analysis identified needle-focused (n = 38) and procedural fear (n = 128) profiles. The procedural profile included more triggers, although VAS-A distributions were similar. Conclusions: RCT fear is heterogeneous in severity and content. Preoperative assessment should evaluate fear intensity, dominant triggers, and avoidance history to support individualized communication and anxiety management.