Intra-oral and a digital SLR camera: plaque image quality assessment

Objectives: Many clinical practices already incorporate intra-oral cameras as part of their procedures for storing dental information about their patients. It would be of interest to compare the reproducibility of a digital SRL based camera and an intra-oral camera in acquiring images of dental plaque and its subsequent measurement. Therefore, a Kodak DCS410 (KJP, UK) digital SLR camera was compared with a standard intra-oral camera (Schick Technologies, UK), the former mounted on a purpose built frame for increased standardisation. Methods: Twenty volunteers were asked to refrain from brushing their teeth for 24 hours and not to eat hard fruit during this period. The study was blind. The criteria for selection of volunteers were that they were over 18 years of age with fully erupted upper anterior teeth and no restorations in the teeth being used for plaque measurement. Natural tooth surfaces were chosen to enable measurement to reflect dental plaque growth unaffected by restorative material surface roughness. After 24 hours the volunteers attended the imaging lab where their teeth were disclosed with Erythrosin FDC Red 3 (Boots Contract Manufacturing, UK). Their upper central and lateral incisors were then imaged together. Two experienced operators took two images from each of the two camera types. The cameras were removed and repositioned between each image taken. These images were then measured later for dental plaque levels in pixels and the data was used to calculate the intra-operator repeatability and the inter-operator reproducibility using Fleiss’ Coefficient of Reliability. Results:

Conclusion: Images acquired using the digital SLR camera permitted measurements of plaque to be made with greater reliability in comparison to a standard intra-oral camera.