Accuracy of various imaging methods for detecting misfit at the tooth-restoration interface in posterior teeth

Clinical Extension of Proximal Carious Lesions Compared to Bitewing Radiographs using Photostimulable Phosphor Plates (PSP): Clinical vs. Radiographic Interproximal Carious Extension

OBJECTIVES

The aim of this study was to evaluate the use of digital bitewing radiographs using photostimulable phosphor (PSP) plates in the estimation of the true extension of proximal carious lesions.

METHODS

The sample size was calculated to be 70 teeth. Adult patients with a minimum of one posterior tooth with primary proximal caries lesions were included. A preoperative bitewing radiograph was taken and the extension of the carious lesion was measured from the most prominent point on the adjacent sound tooth to the deepest axial point of the lesion. An experienced general dentist provided the restorative treatment and made a polyvinyl siloxane impression of the cavity preparation. Clinical caries extension was measured from the most prominent point of the adjacent tooth until the deepest boundary of the axial wall of the preparation on the impression. Postoperative radiographs were taken at the completion of restorative care. The bitewing radiographs were done using PSP plates and caries extension measurements were performed using measuring tools of the digital radiography software. Pairwise comparisons were made between preoperative and postoperative radiographs, and the true clinical depth measurements using paired t-tests.

RESULTS

A significant difference of 0.82 mm was found between preoperative radiographs and clinical measurements (p<0.001). Similarly, comparisons between preoperative and postoperative radiographic measurements showed significant differences of 0.99 mm (p<0.001).

CONCLUSIONS

The study found that the true clinical extension of proximal caries after non-selective caries removal was significantly deeper than the preoperative radiographic extension assessment. This was not influenced by the tooth type, the location of the tooth, or the affected tooth surfaces.

CLINICAL SIGNIFICANCE

When a non-selective caries removal strategy is adopted, clinicians should be aware that PSP bitewing radiographs underestimate the true clinical extension of proximal caries lesions. This will have an impact on clinicians' practice and restorative treatment decisions.

New fluorescence and reflectance analyses to aid dental material detection in human identification

INTRODUCTION

The identification of aesthetic dental materials during clinical dental examination can be challenging especially as patients and dental manufacturers place great emphasis on filling materials being as close as possible in appearance to the natural tooth. This makes dental identification in a forensic setting even more complicated.

OBJECTIVE

The aim of this study was to develop a simple method using photographic analyses to determine differences in fluorescence and reflectance between brands and shades.

METHOD

Three discs of 95 shades of resin composites (n = 285) were produced. Photographs were taken using a digital single-lens reflex (DSLR) camera attached to a dark box illuminated by an ultraviolet (UV) flashlight (wavelength 385 ± 10 nm) in a standardised manner. Images were analysed using an image software. The lightness (L) component according to the CIELAB was recorded. Kruskal-Wallis test was used to compare the mean lightness of the different samples followed by Dunn's test for multiple comparisons. The level of significance was set at P < 0.05.

RESULTS

L values ranged from 238.81 to 49.74. Fluorescence and reflectance were categorized according to crescent L values into 5 categories and organized into a Fluorescence and Reflectance Scale. Overall, dentin shades showed similar L values when compared to the same enamel shade from the same manufacturer. Comparison of L values for shades A1E and A3.5E demonstrated that darker shades had lower L values.

CONCLUSIONS

UV light allowed the recording of the Lightness component of CIELAB of a composite with little variation between images. The Fluorescence and Reflectance Scale allows the examiner to identify a specific brand or restrict the possibilities down to two brands. This information could help in cases of identification especially when ante-mortem data is limited.