The Association Between Coffee Consumption and Local Anesthesia Failure: Social Beliefs and Scientific Evidence.

Introduction In our clinical practice, we have encountered patients who reported the failure of local anesthesia due to excessive coffee consumption and required higher-than-normal doses of local anesthesia. Therefore, our study aimed to assess the awareness and knowledge of coffee consumption, its effect on local anesthesia, and the available scientific evidence among the public, patients, and clinicians in dental practice.  Material and Methods A cross-sectional survey with two sets of questionnaires was designed based on the Likert scale. A 5-point scale was used to assess agreement and frequency. Yes/no and open-ended questions were used for the assessment. Questionnaires were distributed among the clinicians, patients, and the public. Data were analyzed with descriptive linear statistics. Results Of the 430 responses provided by patients and the general public, more than 40% believed that the local anesthetic failure was caused by excessive coffee consumption. Among the 235 responses provided by the clinicians, 65% of the clinicians reported encountering patients with local anesthesia failure and believed it could be due to excessive coffee consumption. However, only 9% of the clinicians were aware of scientific evidence regarding the effect of coffee consumption on local anesthesia failure.  Conclusion Surprisingly, the majority of clinicians believed that caffeine had an effect on the reduction of local anesthesia; however, only a few of them had scientific knowledge. The available scientific evidence relates that caffeine can influence cognitive performance by increasing alertness, as well as sleep deprivation causing stress and anxiety, which partially explains the local anesthetic failure among coffee consumers. Therefore, a stress reduction protocol should be a routine daily practice for a dentist to reduce the failure rate of local anesthesia.