Photobiomodulation After Nonsurgical Root Canal Treatment

This randomized, double-blind controlled clinical trial will evaluate whether adjunctive photobiomodulation improves recovery after nonsurgical root canal treatment in adults with teeth diagnosed with symptomatic apical periodontitis. Participants will receive standard nonsurgical root canal treatment and will be randomized to adjunctive photobiomodulation using the Fotona LightWalker Nd:YAG laser or to an identical simulated laser procedure without laser energy delivery. The study will evaluate mechanical allodynia using maximum occlusal force measurements comparing the treated tooth with the contralateral asymptomatic tooth. Postoperative pain will also be assessed using the Numeric Rating Scale after percussion testing.

Inclusion Criteria: * Adults 18 years of age or older * Able to understand the study procedures and provide written informed consent * Presenting for primary nonsurgical root canal treatment at the University of Minnesota School of Dentistry Graduate Endodontic Clinic * A tooth diagnosed with symptomatic apical periodontitis * A pulpal diagnosis of symptomatic irreversible pulpitis or pulp necrosis * Study tooth is restorable and appropriate for completion of nonsurgical root canal treatment in a single visit * Presence of a functional opposing tooth suitable for reproducible maximum occlusal force measurements * Able to comply with study procedures, including percussion testing and maximum occlusal force measurements * Able and willing to return for the scheduled follow-up visit 7 to 10 days after treatment Exclusion Criteria: * Younger than 18 years of age * Unable or unwilling to provide informed consent in English * Pregnant or known or suspected pregnancy * Previous root canal treatment of the study tooth * Study tooth cannot be treated and obturated during a single treatment visit * Non-restorable tooth, vertical root fracture, root resorption, or suspected or confirmed crack extending onto the root surface * Acute apical abscess requiring incision and drainage or other urgent surgical treatment * Advanced periodontal disease or tooth mobility that may interfere with maximum occlusal force measurements * Current chronic opioid therapy or chronic use of medications that, in the opinion of the investigator, would significantly alter pain perception or interfere with study outcome measures * Unable or unwilling to return for the scheduled follow-up visit * Any medical, physical, or cognitive condition that, in the opinion of the investigator, would prevent safe participation or completion of study procedures * Children * Pregnant women/persons * Fetuses * Neonates * Prisoners * Adults lacking capacity to consent or adults with diminished or fluctuating capacity to consent * Non-English speakers * Individuals unable to read * Employees of the researcher * Students of the researcher * Individuals with a serious health condition for which there are no satisfactory standard treatments * Individuals with fear of negative consequences for not participating * Any other circumstance that could increase vulnerability to coercion or exploitation