Controlled diagnosis-oriented enhancement of automatically segmented radiographs in dentistry

Digital enhancement of radiographs for assessment of interproximal dental caries

OBJECTIVES

Evaluation of a particular digital caries image-enhancing mode (filter) for its effect on the validity of measurements of caries lesion depth.

METHODS

Standardized radiographs of 44 extracted teeth exhibiting interproximal caries lesions were obtained. Six radiographs were obtained of each tooth and digitized. Four radiographs were made using D-speed film with and without soft tissue scattering equivalent (STSE) at normal exposure time (0.32 s) and underexposed (0.16 s). Two were made using E-speed film with STSE normally (0.16 s) and underexposed (0.08 s). On each of the 264 radiographs, 4 independent examiners measured the central depth (CD) of 1 carious lesion per tooth both on the unchanged radiographic image and after use of the filter. Histometric CD assessments provided a gold standard for comparison with the radiographic measurements (validity). Repeated measures ANOVA was calculated for validity in relation to examiner, lesion type, filter, film type, exposure time and STSE.

RESULTS

The lesion type was identified to statistically significantly influence the validity of CD measurements. Examiner in combination with defect type (P<0.001), filter (P = 0.017), exposure (P = 0.027) and film type (P = 0.044) had an additional albeit small effect.

CONCLUSIONS

The lesion type significantly influenced the validity of CD measurements: enamel lesions were less underestimated than dentin lesions.

Detection of Proximal Caries in vitro Using Standard and Task-Specific Enhanced Images from a Storage Phosphor Plate System

Eight dentists evaluated 72 proximal surfaces of premolars with respect to all caries lesions and to lesions into dentine in digital images from a storage phosphor plate system. The images were processed in four different ways: (1) the default algorithm of the standard imaging system (DF); (2) an algorithm correcting for attenuation and visual response (AV), and two proprietary caries-specific enhancement algorithms (3) K1, and (4) K2, respectively. The lesions were validated by histological examination. There were no significant differences in the areas under the receiver operating characteristic curves between differently processed radiographs for the categories of all caries lesions and caries into dentine.

Clinical decision-making using computers: opportunities and limitations

This paper deals with the use of information technology in order to make clinical decisions in dentistry. Since there is a large number of available systems and ongoing projects using computers, we first identify and describe major streams, as well as singular specialties. We underline the need for standards for data format and exchange in addition to the ability of different systems to communicate with each other. We conclude with a five-step recommendation to transform a dental office into digital and how to implement a computer-aided clinical decision support system, which provides action-oriented support in order to reduce the likelihood of human error during dental treatment.