Evaluation of the effect of various endodontic irrigants and medicaments on dentine fluorescence

This study examined the effect of various root canal irrigants and medicaments on dentin fluorescence elicited by 655 nm visible red laser light. To replicate clinical use, irrigants were applied onto dentin samples for 2 min, while medicaments were applied for 2 weeks. Fluorescence values tracked from baseline across the following to 24 h, starting 5 min after exposure. Sodium hypochlorite, hydrogen peroxide, and articaine local anaesthetic (4% articaine with 1:1000,000 adrenaline) all significantly quenched fluorescence (p < 0.0001), which then returned to baseline levels after 20 min. Conversely, elevated fluorescence readings were recorded after 3% mepivacaine (p < 0.05), 0.2% chlorhexidine (p < 0.01) and chloroform (p <0.05). A 2 week application of Ledermix™ paste containing 3% demeclocycline caused an irreversible increase in fluorescence (p < 0.0001). Other tested endodontic materials (15% EDTA, eucalyptus oil, calcium hydroxide, Odontopaste™ clindamycin paste, and distilled water) had no impact on dentine fluorescence. The influences of endodontic materials on dentin fluorescence need to considered when using fluorescence endpoints to guide the progress of root canal treatment.