Quantitative Assessment of Dental Plaque Dynamics

Dental plaque forms as a structured biofilm on tooth surfaces, evolving through stages of initial bacterial adhesion, extracellular matrix production and community maturation. Quantitative assessment of plaque dynamics encompasses methods to measure both the spatial distribution and temporal development of this biofilm. Traditional indices rely on disclosing agents and visual scoring, whereas modern approaches employ optical fluorescence, digital imaging and automated software to capture high-resolution data on plaque coverage, thickness and biochemical composition. Fluorescence-based techniques exploit endogenous porphyrins within mature biofilms, yielding red or green autofluorescence under blue-light excitation and enabling non-invasive quantification of plaque maturity. Planimetric analysis of two-dimensional photographs or three-dimensional intraoral scans provides precise measurements of the surface area occupied by plaque, facilitating longitudinal monitoring. Automated algorithms can further segment visible and non-visible plaque regions, calculate growth rates and generate time-series metrics. Together, these tools offer objective, reproducible data on plaque accumulation and removal, supporting both clinical evaluation of oral hygiene interventions and fundamental research into biofilm ecology and pathogenicity.

Research from Nature Portfolio

A clinical study examined the agreement between quantitative light-induced fluorescence-digital (QLF-D) images and conventional photographs of disclosed plaque in patients wearing fixed orthodontic appliances. The analysis revealed that QLF-D consistently underestimated plaque coverage compared with stained images, with discrepancies increasing at higher plaque levels. Bland-Altman assessment indicated both positive and negative deviations across tooth surfaces, demonstrating a systematic error that limits the current reliability of fluorescence-based quantification in complex oral environments.

Quantitative Assessment of Dental Plaque Dynamics publication trend

The graph below shows the total number of articles in quantitative assessment of dental plaque dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Biofilm: A complex community of microorganisms embedded in a self-produced extracellular matrix on tooth surfaces.

Extracellular polymeric substance (EPS): The polysaccharide-rich matrix secreted by biofilm bacteria that provides structural cohesion and protection.

Quantitative light-induced fluorescence (QLF): An imaging technique using blue light excitation to induce fluorescence in dental plaque for non-invasive quantification.

Planimetry: Measurement of surface area occupied by plaque on two-dimensional or three-dimensional images.

Red fluorescence ratio (R/G ratio): The relative intensity of red to green autofluorescence emitted by plaque under specified excitation, indicative of biofilm maturity.

References

1. Comparison of Quantitative light-induced fluorescence-digital (QLF-D) images and images of disclosed plaque for planimetric quantification of dental plaque in multibracket appliance patients. Scientific Reports (2020).
2. Detecting and monitoring dental plaque levels with digital 2D and 3D imaging techniques. PLOS ONE (2022).
3. Visualization of dental plaque with a 3D-intraoral-scanner—A tool for whole mouth planimetry. PLOS ONE (2022).
4. DenTiUS Plaque, a Web-Based Application for the Quantification of Bacterial Plaque: Development and Usability Study. Journal of Medical Internet Research (2020).
5. Red and Green Fluorescence from Oral Biofilms. PLOS ONE (2016).