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

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. 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 chi2 test was used to compare proportions, and a Pearson correlation test was used to examine correlations between variables. 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. 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. The European Union Drug Regulating Authorities Clinical Trials Database EudraCT201300530531. Date of registration: February 10th, 2014.