Preoperative Factors Associated With Anesthesia Failure For Patients Undergoing Non-Surgical Root Canal Therapy; A National Dental Practice-Based Research Network Dpbrn Study

Abstract

ABSTRACT Introduction: Providing effective local anesthesia is a critical component of the RCT treatment. Patients and providers are more satisfied if local anesthesia is successful. The aim of this study was to analyze data collected by The National Dental Practice-Based Research Network (DPBRN) during non-surgical root canal therapy to identify preoperative factors associated with local anesthesia failure during treatment in the private practice setting. Methods: The DPBRN, consisting of 46 general dentists and 16 endodontists from five geographic areas, enrolled 708 patients in the study, an analysis of patients treated in one visit vs. multiple was done finding no statistical difference in failure rates between the groups in any model. To standardize the treatment rendered, patients treated in multiple appointments were excluded from the study, patients who had general anesthesia, IV sedation or oral sedation were also excluded. Not all survey questionnaires were completely filled out, patients with missing data for a given variable were noted as missing in the analysis. Three methods for defining anesthesia failure: Method 1-patient reported level of numbness, Method 2-provider reported quality of anesthesia, and Method 3-provider reported use of supplemental anesthesia after initial injections required to obtain adequate anesthesia during the procedure. Numerous pre-operative factors were investigated and differences between failure groups, for each failure measure, were estimated by chi-square tests of independence for categorical variables and t-tests for numeric variables. A stepwise linear regression model using AIC statistic as fitness criteria for each method was created to identify variables associated with failure outcomes. The regression models give odds ratios for factors associated anesthesia failure. Results: Overall anesthesia failure rates were 4.90%, 14.61% and 29.96% for Methods 1, 2 and 3 respectively. Method 1 found provider experience, diabetes, current smoking habit, patient expected outcome of treatment, sharp pain, and spontaneous pain to be significant when analyzed individually. The regression model found provider experience, diabetes, preoperative fear, number of days in pain, sharp pain, spontaneous pain and severe pain to be significantly correlated with anesthesia failure. Method 2 found provider type, diabetes, pain interference in recreational and social activities, pain provoked by stimulus, pain made worse by stress, percussion sensitivity, biting sensitivity, and presence of a sinus tract to be significant when analyzed individually. The regression model found provider experience, provider type, diabetes, and pain interfering in recreation and social activities to be significantly correlated with anesthesia failure. Method 3 found provider type, patient age, pain interference with daily activities, sharp pain, pain provoked by stimulus, maxillary vs mandibular, presence of a periapical radiolucency, responsiveness with cold, lingering pain with cold, and pulp vitality confirmed with bleeding upon access to be significant when analyzed individually. The regression model found provider experience, provider type, patient income from $10,000-29,000, diabetes and pain interfering in recreational and social activities to be significantly correlated with anesthesia failure. Conclusions: The results from this study generally agree with prior studies finding that symptomatic teeth with vital pulps have more anesthesia failures. Patient self-reported history of diabetes was found to lead to more anesthesia failures in multiple models; further research is needed to understand the mechanism of anesthesia failure related to diabetes. Multiple models found results related to provider experience and provider training found that more experienced providers and those with higher levels of training had significantly fewer anesthesia failures. Pulpal anesthesia is more difficult to achieve than soft tissue anesthesia. Prior research reveals oral surgery departments are responsible for anesthesia training in most dental school and endodontic departments are not involved; the results of this study indicate that endodontic departments should be involved in a team approach with oral surgery departments regarding local anesthesia training in dental schools to shorten the learning curve for providers. Keywords: Endodontics, Local Anesthesia, Practice Based Research Network