Quantification of dental plaque in the research environment

The University of Manchester, Turner Dental School, Unit of Prosthodontics, Higher Cambridge Street, Manchester M15 6SH, UK.
Journal of Dentistry (Impact Factor: 2.75). 04/2005; 33(3):193-207. DOI: 10.1016/j.jdent.2004.10.017
Source: PubMed


To review the established and novel methods of plaque quantification employed in dental research, including a discussion of their merits and to present a new method of planimetrically measuring plaque using light induced fluorescence.
Quantitative light-fluorescence (QLF) images were acquired from the buccal surfaces of an individual who had refrained from oral hygiene both with and without traditional plaque disclosure. Digital photographs were also taken. Images were analysed using a novel method and a percentage plaque index produced.
Traditional plaque indices are problematic due to their integral nature and their failure to detect small, but potentially clinically relevant changes in plaque area. The use of a fluorescent technique demonstrated good reliability although there was no correlation between red fluorescent plaque and total disclosed plaque suggesting that the auto-fluorescing plaque is not a good measure of total plaque volume.
The use of planimetric techniques can increase the power of plaque studies, potentially reducing the number of subjects and time required to separate therapies or products. Fluorescent methods of quantification have potential as they enable clear separation of the plaque covered and non-covered tooth surfaces.

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    • "Plaque determination and analysis have been traditionally performed in dental clinics using various manual indices such as those developed by Ramfjord, Silness and Loe, Turesky, and Elliott [5]. However, according to Pretty et al., " traditional plaque indices are problematic due to their integral nature and their failure to detect small, but potentially clinically relevant changes in plaque area " [6]. These procedures are also time consuming, more subjective, and more invasive to patients. "

    Full-text · Article · Jan 2016
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    • "When a tooth with plaque is excited by a visible light of 405 nm from the QLF, red fluorescence were shown on the plaque accumulation area [6] [7], and the QLF was able to detect and quantify the area. Previous studies have shown that mature plaque may produce red auto-fluorescence and it is associated with products of microbe metabolism which are called porpyrins [5] [6]. The porphyrins are known to be produced from late colonizing oral bacteria, such 1572-1000/© 2015 Elsevier B.V. All rights reserved. "
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    ABSTRACT: Background: The aims of this study were to compare the relationship between red fluorescent plaque (RF plaque) area by Quantitative Light-induced Fluorescence-Digital (QLF-D) and disclosed plaque area by two-tone disclosure, and to assess the bacterial composition of the RF plaque by real time-PCR. Methods: Fifty healthy subjects were included and 600 facial surfaces of their anterior teeth were examined. QLF-D was taken on two separate occasions (before and after disclosing), and the RF plaque area was calculated based on Plaque Percent Index (PPI). After disclosing, the stained plaque area was analyzed to investigate the relationship with the RF plaque area. The relationship was evaluated using Pearson correlation and paired t-test. Then, the RF and non-red fluorescent (non-RF) plaque samples were obtained from the same subject for real-time PCR test. Total 10 plaque samples were compared the ratio of the 6 of bacteria using Wilcoxon singed rank test. Results: Regarding the paired t-test, the blue-staining plaque area (9.3±9.2) showed significantly similarity with the RF plaque area (9.1±14.9, p=0.80) at ΔR20, however, the red-staining plaque area (31.6±20.9) presented difference from the RF plaque area (p<0.0001). In addition, bacterial composition of P.intermedia and S.anginosus was associated with substantially more the RF plaque than the non-RF plaque (p<0.05). Conclusions: The plaque assessment method using QLF-D has potential to detect mature plaque, and the plaque area was associated with the blue-staining area using two-tone disclosure.
    Full-text · Article · Dec 2015 · Photodiagnosis and photodynamic therapy
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    • "Calibration between examiners are always needed due to the subjective nature of the indices. This requires a lot of time in clinical studies [8]. "
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    ABSTRACT: Background: The aim of this study was to evaluate validity and reliability of autofluorescence-based plaque quantification (APQ) method. Methods: The facial surfaces of 600 sound anterior teeth of 50 subjects were examined. The subjects received dental plaque examination using Turesky modified Quigley Hein plaque index (QHI) and Silness & Löe plaque index (SLI). The autofluorescence images were taken before the plaque examination with Quantitative Light-induced Fluorescence-Digital, and Plaque Percent Index (PPI) was calculated. Correlation between two existing plaque indices and the PPI of the APQ method was evaluated to find which level of plaque redness on tooth (ΔR) by the APQ method shows the highest correlation. The area under the ROC curve (AUC) analysis and intra- and inter-examiner reliability tests were performed. Results: The PPIΔR20 of the APQ method showed a moderate correlation with two existing plaque indices (rho of QHI=0.48, SLI=0.51). This methodology fell in the fair category and it had an excellent reliability. The APQ method also showed possibility to detect heavy plaque with fair validity. Conclusions: The APQ method demonstrated excellent reliability, and fair validity, compared with 2 conventional indices. The plaque quantification described has the potential to be used in clinical evaluation of oral hygiene procedures.
    Full-text · Article · Oct 2015 · Photodiagnosis and photodynamic therapy
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