Detection of subgingival calculus and dentine
caries by laser fluorescence.
Lasers, like the Diagnodent, have been shown to be far more
accurate than humans in detecting decay in teeth, and it looks
like lasers can find potential periodontal (gum) problems better
than dentists and hygienists as well. - DFB
Detection of subgingival calculus and dentine caries by laser
fluorescence.
J Periodontal Res. 2004 Feb; 39(1): 59-65
Kurihara E, Koseki T, Gohara K, Nishihara T, Ansai T, Takehara
T
OBJECTIVES: Detection of subgingival calculus and dentine caries
in the bottom of deep periodontal pockets is often difficult without
visual observation. We thus examined the possibility of its detection
using autofluorescence induced by laser irritation.
METHODS: Autofluorescence was measured at various excitation and
emission wavelength settings in five specimens each of sound dentine
and enamel, subgingival calculus, and root caries. Periodontopathic
model teeth with bacterial cells and blood clots were also irritated
by laser to obtain autofluorescent images.
RESULTS: Subgingival calculus and dentine caries showed a characteristic
700 nm emission when excited at 635 nm or a 720 nm emission when
excited at 655 nm; sound dentine or enamel, however, did not.
The calculus differentiation power, however, was higher with excitation
at 635 nm than at 655 nm. The autofluorescent images photographed
at an excitation of 633 nm provided clear calculus identification
in periodontopathic model teeth when a 700 nm band-pass filter
or a 700 nm high-pass filter was used. However, fluorescence intensity
was masked when the calculus surface was covered by bacterial
cells or blood clots. For clinical use, it would be important
to remove subgingival plaque and debris from root surfaces before
attempting to detect subgingival calculus and root caries with
this manner.
CONCLUSION: The autofluorescence method employing excitation of
633-635 nm was found to be a powerful tool for detecting subgingival
calculus and root caries.