DIAGNOdent laser fluorescence assessment of endodontic infection.
BACKGROUND
Real-time assessment of the microbial status of the root canal system would be useful in clinical endodontic practice for determining endpoints of biomechanical treatment. This laboratory study used an existing laser fluorescence device, the DIAGNOdent (KaVo, Biberach, Germany), in a proof-of-concept study.


METHODS
Visible laser red light (wavelength 655 nm) was used to elicit fluorescence emissions in the near-infrared range from infected and uninfected root canals. A prototype sapphire tip designed for periodontal assessment was used to analyze the pulp chamber and coronal third of the root canal system in extracted teeth. The fluorescence properties of bacterial cultures, monospecies biofilms in root canals, pulpal soft tissues, and sound dentin were also evaluated, together with 50 extracted teeth with known endodontic pathology.


RESULTS
Sound dentin and healthy pulpal soft tissue gave an average fluorescence reading of 5 (on a scale of 100), whereas biofilms of Enterococcus faecalis and Streptococcus mutans established in root canals showed a progressive increase in fluorescence over time. Fluorescence readings reduced to the "healthy" threshold reading of 5 when root canals were endodontically treated, and the experimentally created bacterial biofilms were removed completely. High fluorescence readings were recorded in the root canals and pulp chambers of extracted teeth with radiographic evidence of periapical pathology and scanning electron microscopy evidence of bacterial infection.


CONCLUSIONS
The use of the DIAGNOdent fluorescence approach for the assessment of the status of the pulp chamber and root canal system holds promise for clinical application; once more, flexible tips can be developed for gaining greater penetration into middle and apical thirds of the root canal.
University of Queensland School of Dentistry, Brisbane, Australia.
Andrew L
AL
Sainsbury
Philip S
PS
Bird
Laurence J
LJ
Walsh
D001424:Bacterial Infections / Q000175:diagnosis*; D018441:Biofilms; D003782:Dental Pulp / Q000382:microbiology / Q000473:pathology; D003786:Dental Pulp Cavity / Q000382:microbiology / Q000473:pathology; D003788:Dental Pulp Diseases / Q000175:diagnosis* / Q000382:microbiology; D003789:Dental Pulp Exposure / Q000175:diagnosis / Q000382:microbiology; D003804:Dentin / Q000382:microbiology / Q000473:pathology; D013293:Enterococcus faecalis / Q000502:physiology; D004867:Equipment Design; D005453:Fluorescence; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D010483:Periapical Diseases / Q000175:diagnosis / Q000382:microbiology; D012390:Root Canal Therapy; D013290:Streptococcal Infections / Q000175:diagnosis; D013295:Streptococcus mutans / Q000502:physiology