Effect of Whitening Toothpastes and Brushing on Microhardness of Esthetic Restorative Materials.

OBJECTIVE: Whitening toothpastes are widely used. Hence, it is important to understand their effect on the surface properties of restorative materials. To evaluate the effect of three over-the-counter whitening toothpastes and toothbrushing simulation on microhardness of three restorative materials. STUDY DESIGN: Forty cylindrical (10×2mm) specimens were prepared from each restorative material and randomly assigned into four groups/10 each according to the whitening toothpastes used and distilled water (control). All specimens were measured for microhardness (Baseline-T1). The specimens were brushed with a soft brush using an in vitro tooth-brushing simulator with the assigned whitening toothpaste using the same setting for brushing cycles/load for all groups. Specimens were then measured for microhardness (T2) similar to baseline. RESULTS: The highest (mean±SD) microhardness after application of the whitening toothpastes and brushing was recorded for Intense White and Filtek Z250 XT (127.6±1.8), followed by Optic White and Fuji ll LC (73.9±0.9) and Optic White and Photac Fill (72.7±1.3). There was statistically significant difference for microhardness between pre- and post-application of the whitening toothpastes and brushing for all tested restorative materials (P=0.0001). The microhardness of Filtek Z250XT with 3D White post-application of the whitening toothpastes and brushing was lowest compared to other toothpastes and control (P=0.0001). CONCLUSION: Microhardness increased after application of the whitening toothpastes and toothbrushing simulation for all combination of tested restorative materials and whitening toothpastes. The microhardness of FIiltek Z250XT with 3D White post-application of the whitening toothpastes and brushing was lowest compared to other toothpastes and control.

Evaluation of concordance between clinical and histopathological diagnoses in periapical lesions of endodontic origin.

Background/purpose: Periapical lesions of endodontic origin are often diagnosed based on the clinical and radiological presentations that may be different from the histological diagnoses. The purpose of this study was to assess the concordance between the clinical diagnosis of these lesions and the histopathological diagnoses and to analyze their clinical and pathological features. MATERIALS AND METHODS: Biopsies of periapical lesions of endodontic origin diagnosed in the histopathology laboratory between 2006 and 2017 were retrieved from the database and used to conduct this retrospective review. Clinical data were obtained, and tissue samples were re-evaluated. The overall agreement between the clinical and histological diagnoses was tested utilizing the Cohen kappa (k). RESULTS: A total of 317 periapical biopsy specimens were included in this study which consisted of 137 periapical granulomas, 174 periapical cysts, and six periapical scars. Generally there was weak overall agreement between the clinical and histological diagnoses of periapical granuloma and periapical cysts (Cohen kappa, k = 0.059). CONCLUSION: The findings of this study indicate that clinical/radiographic examinations are not able to preoperatively determine whether a periapical lesion is a cyst or a granuloma and highlights the importance of developing a reliable nonsurgical diagnostic method to differentiate periapical lesions.