QLF is not readily suitable for in vivo denture plaque assessment

Abstract 

Objectives

Current methods available for denture plaque assessment utilise visual and planimetric techniques. This paper evaluates the use of the Quantitative Light-induced Fluorescence system (QLF™) in image capture of denture plaque and the suitability of these images for planimetric plaque measurement. It is proposed that fluorescence imaging could provide a valuable and sensitive standardising method for plaque assessment in clinical trials for denture cleansing products and denture hygiene. Indeed, the detection of red fluorescent plaque using the QLF system is indicative of black-pigmented obligate anaerobes and mature plaque.

Methods

The QLF system was evaluated in a clinical study for use in denture plaque assessment in comparison to white light based image capture.

Results

Despite appearing as a promising system for denture plaque quantification, this study revealed numerous problems associated with the QLF system including small focal depth, thus large numbers of images and processing time were required. In addition, differential fluorescence of acrylic made images unsuitable for plaque quantification.

Conclusion

QLF is unsuitable for in vivo denture plaque assessment. However, the visualisation of red autofluorescence, indicating mature plaque, remains an important clinical use of QLF for denture hygiene assessment.

Keywords: Denture plaque, QLF, Clinical study, Planimetric assessment, Fluorescence, Image analysis