Ice versus lidocaine 5% gel for topical anaesthesia of oral mucosa – a randomized cross-over study

BACKGROUND: Topical anaesthesia is important to optimize pain control during dental injection. Our aim was to describe a new simple method for topical anaesthesia of oral mucosa and to compare the effectiveness of ice and lidocaine 5% gel for topical anaesthesia of oral mucosa. METHODS: A total of 40 patients aged 10.7–19.5 years were included. The side and method of application were both randomized. Heart rate was recorded, and discomfort and pain were evaluated with a visual analogue scale (VAS). A paired t-test was used to compare mean values, a chi(2) test was used to compare proportions, and a Pearson correlation test was used to examine correlations between variables. RESULTS: When ice was used, buccal injection VAS pain was rated lower (p = 0.044), and VAS discomfort was rated higher (p = 0.001), in comparison to when lidocaine 5% gel was used. There was no significant difference in relative heart rate change between ice and lidocaine 5% gel at either needle stick or injection. Lidocaine 5% gel produced a relative heart rate reduction after palatal injection (0.99 ± 0.06) while buccal injection produced an increased relative heart rate (1.02 ± 0.08) (p = 0.010). Unpleasant taste was more frequently reported when lidocaine 5% gel was used (p = 0.025). An application time of 1 min was sufficient for both ice and lidocaine 5% gel to achieve pain reduction from needle stick in buccal mucosa. CONCLUSION: The cheap and readily available described method using ice for topical anaesthesia of oral mucosa before dental injection is an effective alternative to lidocaine 5% gel. TRIAL REGISTRATION: The European Union Drug Regulating Authorities Clinical Trials Database EudraCT201300530531. Date of registration: February 10th, 2014.