METHODOLOGY: Jaw sections containing 67 teeth (86 roots) were collected from nine fresh, unclaimed bodies that were due for cremation. Imaging was carried out to detect AP lesions using film and digital PR with a centred view (FP and DP groups); film and digital PR combining central with 10˚ mesially and distally angled (parallax) views (FPS and DPS groups). All specimens underwent histopathological examination to confirm the diagnosis of AP. Sensitivity, specificity and predictive values of PR were analysed using rater mean (n = 5). Receiver operating characteristics (ROC) analysis was carried out.
RESULTS: Sensitivity was 0.16, 0.37, 0.27 and 0.38 for FP, FPS, DP and DPS, respectively. Both FP and FPS had specificity and positive predictive values of 1.0, whilst DP and DPS had specificity and positive predictive values of 0.99. Negative predictive value was 0.36, 0.43, 0.39 and 0.44 for FP, FPS, DP and DPS, respectively. Area under the curve (AUC) for the various imaging methods was 0.562 (FP), 0.629 (DP), 0.685 (FPS), 0.6880 (DPS).
CONCLUSIONS: The diagnostic accuracy of single digital periapical radiography was significantly better than single film periapical radiography. The inclusion of two additional horizontal (parallax) angulated periapical radiograph images (mesial and distal horizontal angulations) significantly improved detection of apical periodontitis.
METHODS: An Agilent 1200 series high-performance liquid chromatography (HPLC) unit using a diode-array detector (DAD) has been employed and optimized to detect IPTS in cosmetic products. For the separation, a reverse-phase Hypersil Gold C8 column (5 μm, 4.6 mm i.d. 250 mm) 5 mM tetrabutylammonium phosphate buffer 50 : 50, (v/v) solution in acetonitrile as mobile phase, in isocratic mode and a flow rate of 0.8 mL min(-1) were used. A second method using a gas chromatography/mass selective detector GC-MSD was also developed to confirm the IPTS identity in the cosmetic products.
RESULTS: Recoveries of IPTS from cosmetic matrices such as a lotion, cleansing milk and a cream ranged from 94.0% to 101.1% with <5% relative standard deviation (%RSD) showing good accuracy and repeatability of the method. The six-point calibration curves (determined over the range 0.5-50 μg mL(-1) ) have a correlation coefficient of 0.9999 (based on HPLC peak area) and 0.9998 (based on HPLC peak height). The intra- and interday precisions (measured by the %RSD) of the method were <2% and <5%, respectively, indicating that the developed method is reliable, precise and reproducible. The detection and quantification limit of the method were found to be 0.5 μg mL(-1) and 1.6 μg mL(-1) , respectively. Analyses of 83 commercial cosmetics showed no presence of IPTS.
CONCLUSIONS: The validation data indicated that this method was suitable for the quantitative analysis of IPTS in commercial cosmetics. This method is applicable for analyses of trace levels of IPTS in cosmetics and has the advantage of using only simple sample preparation steps.