Comparing Skin Refrigerant to Topical Anesthetic as a Pre-Injection Anesthetic

Objective: To determine the effectiveness of a skin refrigerant as compared to a topical anesthetic gel in reducing the pain experienced during posterior palatal local anesthetic infiltration using a split-mouth design. Methods: Sixteen patients received a 5-second application of a skin refrigerant (1,1,1,3,3-Pentafluoropropane/1,1,1,2-Tetrafluorethane, Pain Ease, Gebauer) and a 2-minute application of a topical anesthetic gel (20% Benzocaine gel, Topex, Sultan) in the posterior palatal area prior to a 10-second infiltration of 0.3-mL of a local anesthetic solution (2% Xylocaine with 1:100,000 Epinephrine, Astra) using a 30-gauge needle. There was a 5-minute interval between the two pre-anesthetic tissue applications and local anesthetic injections. Each patient rated the pain experienced after each injection using a 100-mm Visual Analogue Scale (VAS) with end points “no pain” and “worst possible pain.” The VAS score was calculated by measuring the millimeter distance from the left end of the scale (i.e., no pain). A mean (mm) and standard deviation was determined per group (n=16). Data was analyzed with a paired t-test (alpha=0.05). Results: The mean VAS for each of the two groups: skin refrigerant – 17.7 ± 15.3 mm; topical anesthetic – 26.2 ± 18.0 mm. The skin refrigerant significantly reduced the pain experienced during local anesthetic infiltration compared with the use of topical anesthetic gel (p=0.02). Conclusion: The use of a skin refrigerant as a pre-injection anesthetic was shown to be effective in reducing the pain experienced by patients receiving a posterior palatal local dental injection compared to the use of a topical anesthetic gel. Discussion: Other potential benefits of the skin refrigerant would include decreased application time, ease of application and avoidance of displeasing taste as compared to the use of topical anesthetic.