A digital SLR or intra-oral camera: preference for acquisition within an image analysis system for measurement of disclosed dental plaque area within clinical trials

Objectives: The aim of this investigation was to compare the accuracy and reproducibility of images acquired from two types of camera (digital SLR camera, Kodak DCS410, KJP, UK and an intra‐oral camera, Schick Technologies, UK) for application within an imaging system used for the quantification of disclosed dental plaque. Methods: Subjects refrained from brushing their teeth for 24 h. Their teeth were then disclosed with Erythrosin FDC Red 3 and duplicate sets of images were obtained by each examiner of the upper central and lateral incisors. Images were then saved and measured for dental plaque area. These data were used to calculate reliability. Results: No statistically significant bias in the measurements of plaque area was found. The reliability results showed the method was reliable. However, the image analysis system incorporating the 35 mm SRL camera was more reliable for both operators, as demonstrated by their intra‐operator results. This was also collaborated by the inter‐operator results. Conclusion: In this investigation the digital SLR camera combined with the image analysis system and frame permitted greater reliability of dental plaque surface area measurements than the digital intra‐oral camera. This conclusion was derived both from the reliability data and from the perceived ease of use and flexibility of both camera types. When combined with the use of the custom‐made frame, the images using the digital SLR camera were highly reproducible, confirming the systems application within clinical trials.