Apical periodontitis is a very common condition. Epidemiological research suggests that nearly 50% of the global adult population may have had at least one affected tooth and that approximately 40% of root-filled teeth may be associated with apical periodontitis. Since apical periodontitis is caused by microorganisms in the root canal system, every measure taken to reduce the microbial burden during treatment is of importance. The high prevalence of apical periodontitis associated with root-filled teeth suggests that dentists in general may have problems eliminating microorganisms in the root canals and avoiding contamination of the root canals when performing endodontic treatments. 

Most non-surgical endodontic treatments are performed by general dentists. It can be assumed that improvement of endodontic infection control in general dentistry could have a positive impact on the overall outcome of endodontic treatments. The aim of this project was to render a better understanding of endodontic infection control in general dentistry. 

Study I and II consisted of a two-folded cross-sectional questionnaire regarding general dentists’ endodontic infection control measures, sources of knowledge, and self-assessed skills. Study III and V consisted of two cross-sectional mixed methods surveys regarding dental health care workers’ experiences during the COVID-19 pandemic, and perceived barriers and facilitators to hand hygiene adherence. Study IV was a prospective observational study which evaluated endodontic operative field asepsis by assessing general dentists’ ability to reduce the contamination to a non-cultivable level.

The vast majority reported using a dental dam and most disinfected the endodontic operative field. However, one in 10 did not use hand disinfectant at all during endodontic treatments. More than half of the respondents did not know, or did not believe, that the initial diagnosis affected the outcome of their endodontic treatments, indicating an underestimation of microbiological factors’ impact on treatment outcome. The majority graded their endodontic treatment outcome and their infection control adherence as good, though several admitted not fully adhering to the infection control guidelines. The clinical study found relatively high levels of contamination on the operative field in general dentistry, which indicates poor aseptic control.

Knowledge, education, and a supportive work environment were perceived as facilitators to infection control. Recurring themes regarding barriers were a lack of training and performance feedback, conflicting messages and conflicting demands, and lack of resources (mainly time). Several respondents reported situations where they had felt pressured to make compromises with their infection control measures.  Most based their endodontic management of patients on what they had been taught during their undergraduate training. A third of the general dentists had not attended any continuing endodontic education. 

The results from the included studies show that although dental professionals may have the intention to adhere to infection control guidelines, they are influenced by various other factors, which may result in nonadherence. There are also indications that the awareness of the risks of contamination occurring during treatment, and the subsequent negative impact contamination may have on treatment outcome, may be lacking. Although both dentists and other dental health care workers graded their knowledge and performance of, for example hand hygiene, as good, several other responses indicated their estimations may be misestimations. 

Further research into what affects endodontic infection control performance is needed, particularly regarding hand hygiene. Additional attention must be paid to the settings in which general dentists operate, as the ability to choose different measures may be limited by environmental and organizational factors. The future challenge is to raise awareness in general dentistry about the microbiological aspects of endodontic treatments and the critical importance of infection control. It would be of value to add more observational data to compare views with what is performed in clinical practice.