The relationship between pre-anesthetic fear, pain expectation, and pain perception during endodontic injections: a prospective observational clinical study

Fear of local anesthesia is one of the most common sources of anxiety in dental practice and may influence how patients perceive pain during treatment. Fear and pain expectation may contribute to the pain experience during dental injections. This clinical study aimed to evaluate the relationship between pre-anesthetic fear, expected pain, and the experienced pain during endodontic anesthesia. A total of 120 patients requiring inferior alveolar nerve block (IANB) or posterior superior alveolar block (PSAB) were included in the study. Before the injection, patients rated their level of fear and expected pain using separate Visual Analog Scales (VAS). Immediately after the injection, the pain experienced during anesthesia was recorded using the same scale. Associations between variables were examined using correlation analysis and robust linear regression models. The mean expected pain score (3.9 ± 2.4) was higher than the pain actually experienced during injection (2.3 ± 1.3). A significant positive correlation was observed between pre-anesthetic fear and experienced pain (ρ = 0.33, p < 0.001), as well as between expected pain and experienced pain (ρ = 0.48, p < 0.001). In the regression analysis, fear was initially associated with pain perception (β = 0.15, p < 0.001); however, this association became nonsignificant after including expected pain in the model (β = -0.03, p = 0.63). Expected pain remained the strongest statistical correlate of pain experienced during anesthesia (β = 0.27, p < 0.001). Pre-anesthetic fear was associated with injection pain mainly through patients’ pain expectations rather than directly. Expectation management may therefore be a promising clinical target, although this observational finding requires confirmation in controlled trials.