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

Abstract

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.

Keywords: caffeine; coffee consumption; failure; local anaesthesia.

Figure 1. Box-and-whiskers plot of the distribution of daily caffeine intake among dental local anesthesia (LA) failure and non-failure groups

The green box indicates the interquartile range (IQR) of the no-dental LA failure group, which shows a lower range of daily caffeine intake compared to the red box (IQR) of the dental LA failure group (Mann-Whitney U test p-value = 0.01**). The white lines in the middle of the boxes indicate the median, which is lower in the no-dental LA failure group (97.2 mg) compared to the dental LA failure group (133.4 mg) (median test p-value = 0.008**). The rounded dots (o) indicate mild outliers (> 1.5* IQR and  < 3* IQR), while the stars (*) indicate extreme outliers (> 3* IQR).

Figure 2. Types of LA techniques in which clinicians encountered dental LA failure

LA: local anesthesia

Figure 3. Clinicians’ responses to encountering patients with frequent dental LA failure due to excessive coffee consumption

LA: local anesthesia

Figure 4. Public's and clinicians' beliefs on the effects of coffee on dental anaesthesia

The Chi-squared test p-value was < 0.001, which indicates highly significant differences between the public's and the clinicians’ beliefs. The median category for public participants was those who think that coffee rarely causes dental LA failure, while the median category for clinicians was those who think coffee sometimes causes dental LA failure. LA: local anesthesia