Diagnostic accuracy of combined pulp sensibility tests for detecting post-anesthetic pulpal anesthesia in mandibular molars with symptomatic irreversible pulpitis

Attaining pulpal anesthesia (PA) is the key to painless endodontic treatment. Few studies have measured post-anesthetic PA using cold and/or electric stimuli but heat test has never been used for such purpose. Our study employed different combinations of Heat Test (HT), Cold Test (CT) and electrical pulp test (EPT) to detect post-anesthetic PA in mandibular molars with Symptomatic Irreversible Pulpitis. One hundred healthy endodontic patients received Inferior Alveolar Nerve Block with 2% lignocaine containing 1:200000 adrenaline. After achieving lip numbness, PA was evaluated using EPT, CT and HT. Negative response to PSTs indicated attainment of PA. Teeth exhibiting negative response to at least 2 PSTs were subjected to endodontic intervention. Outcomes of combinations of PSTs were compared with pain during endodontic treatment (gold standard test) using Fisher-Freeman-Halton exact test. No/mild pain (Heft Parker visual analogue scale) during endodontic treatment was considered as anesthetic success. Eighty-three patients completed the study and were statistically analysed. An overall significant association was found between PST combinations and the incidence of intraoperative pain (P = 0.004). The triple combination (EPT, CT and HT) showed the lowest risk of moderate/severe pain at 14.3% (95% CI 7.6-25.3). In individual test analysis, only Heat Test showed a statistically significant association with intraoperative pain (P = 0.001). This highlights the importance of using all 3 PSTs in detecting the presence of PA. Clinical trial registration: https://ctri.nic.in/ , Registration number: CTRI/2023/03/051049, Registration date: 24 March.