Detection and quantification of dental plaque based on laser-induced autofluorescence intensity ratio values

Abstract

The aim of this study was to evaluate the applicability of laser-induced autofluorescence (LIAF) spectroscopy to detect and quantify dental plaque. LIAF spectra were recorded in situ from dental plaque (0–3 grades of plaque index) in 300 patients with 404 nm diode laser excitation. The fluorescence intensity ratio of the emission peaks was calculated from the LIAF spectral data following which their scatter plots were drawn and the area under the receiver operating characteristics were calculated. The LIAF spectrum of clinically invisible grade-1 plaque showed a prominent emission peak at 510 nm with a satellite peak around 630 nm in contrast to grade 0 that has a single peak around 500 nm. The fluorescence intensity ratio (F510/F630) has a decreasing trend with increase in plaque grade and the ratio values show statistically significant differences (p<0.01) between different grades. An overall sensitivity and specificity of 100% each was achieved for discrimination between grade-0 and grade-1 plaque. The clinical significance of this study is that the diagnostic algorithm developed based on fluorescence spectral intensity ratio (F510/F630) would be useful to precisely identify minute amounts of plaque without the need for disclosing solutions and to convince patients of the need for proper oral hygiene and homecare practices.

Diagnosis and staging of caries using spectral factors derived from the blue laser-induced autofluorescence spectrum

“…2) of stage III and IV were assigned to oral bacteria and endogenous porphyrins, such as protoporphyrin IX, which were synthesised by the oral bacteria in the carious lesions. 24,28–30 The species complexity of oral bacteria, their activities, and ability to accumulate on the tooth surfaces may be responsible for the inconsistent appearance of the peak(s) in the AF spectrum and the high spread of two-peak ratio data. Regarding the two peaks at wavelengths longer than 600 nm, dental plaque can be a possible entity in absence of caries.…”

“…Regarding the two peaks at wavelengths longer than 600 nm, dental plaque can be a possible entity in absence of caries. 24 The production and detection of two fluorescence peaks can be possible because dental plaque resides everywhere on the tooth surface as a thin biofilm or mass of bacteria. According to the stage description (Table 1), however, all carious lesions (from stage II to IV) accompany visible morphology modifications from the surface to the deep subsurface of the tooth; peaks after 600 nm without surface modification can be excluded as evidence of a carious lesion.…”

Fluorescence ratiometric classifier for the detection of skin pathologies

“…11 A recent study from the same group implemented fluorescence ratiometric approach (F510/F630) at 404 nm excitation wavelength for discriminating dental plaques and achieved 100% sensitivity and 100% specificity. 12 Additonally, Suresh and associates used reflectance spectroscopy based on oxy-Hb and deoxy-Hb bands for monitoring the wound healing process in diabetic foot ulcers 13 …”

Deep learning-based dental plaque detection on primary teeth: a comparison with clinical assessments

“…Additionally, disclosing agents can temporarily stain oral mucosa and the lips, which is a major esthetic issue. Techniques using laserinduced autofluorescence spectroscopy and digital imaging analysis using the HIS color space have also been described in the literature, but equipment cost and technique standardization are major drawbacks to the popularization of such methods [7][8][9]. Thus, there is a need to develop a costeffective and convenient technique to objectively detect and quantify dental plaque.…”