Effect of precooling on the assessment of pain during local anesthesia in adults: A systematic review and meta-analysis.

Background: Various methods aim to reduce pain from local anesthesia injections. While commonly used, topical anesthetics have limitations. This systematic review aimed to assess whether precooling is a more effective alternative to topical anesthetics for pain control during local anesthesia injections in adults. Material and Methods: The review followed PRISMA guidelines and used the PICO framework. The protocol was registered in PROSPERO (CRD42023446314). Independent searches were conducted in PubMed/MEDLINE, SCOPUS, and Web of Science for studies published up to November 2024. Articles meeting the eligibility criteria were included. Data were extracted by one author and verified by another. A meta-analysis was performed to evaluate pain between the precooling and topical anesthetic groups after anesthesia and during needle insertion. Results: Eight randomized clinical trials met the inclusion criteria, with a combined sample of 415 patients. Six of the eight studies reported lower pain scores in patients who received precooling compared to those treated with topical anesthetics. Various agents were used for both local cooling and topical anesthesia. Meta-analysis showed statistically significant pain reduction in favor of precooling after anesthesia; however, no significant differences were found during needle insertion. Conclusions: Precooling may be an effective alternative to topical anesthetics, reducing pain associated with needle insertion and anesthetic injection in adults. Further research is warranted to establish a standardized application protocol.