Quantitative assessment of artefacts and identification of gaps in prosthetic crowns: a comparative in vitro study between periapical radiography and CBCT images

Objectives:To evaluate, in an in vitro study, the quantity of artefacts generated by two different restorative materials, and to determine the diagnostic accuracy of cone beam CT (CBCT) scans and periapical radiographs in identifying gaps in prosthetic crowns.Methods:A total of 30 teeth restored with metal-ceramic (n = 15) and all-ceramic (n = 15) crowns, properly adapted and with 0.30- and 0.50 mm gaps, underwent CBCT exams (with voxel sizes of 0.25 and 0.30 mm) and periapical radiographs. The artefacts generated by two different crowns were quantified and compared by the Mann–Whitney test. In addition, five examiners evaluated the presence or absence of gaps in periapical radiographs and CBCT images. The accuracy of tests was determined by the area under the receiver operatring characteristic curve and these values were compared by using the Kruskal–Wallis test.Results:There was no significant difference in artefact values between the different restorative materials and the different resolutions of CBCT images. Regarding the accuracy of the tests evaluated, periapical radiography and CBCT with voxel size 0.25 mm showed the best performance for smaller gaps (0.30 mm). For larger gaps (0.50 mm), all exams tested showed the same performance.Conclusions:Periapical radiography was still the most cost-beneficial method for the diagnosis of maladaptation in dental restorations. CBCT exams did not improve accuracy in detecting gaps in prosthetic crowns.     

Can mobile units improve the strategies for cervical cancer prevention?

Cervical cancer is a serious public health problem in women in developing countries because of absence or ineffectiveness of screening programs. Several biases to access medical care and inequity of public health system in a continental country like Brazil limit the implementation of adequate programs to appropriately prevent the cervical cancer. Therefore, the aim of this study was to evaluate the results of applying the mobile unit (MU) for cervical cancer screening. From May 2003 to May 2004, a cervical cancer screening was offered to women aged 20–69 years, residing in 19 municipal districts of the Barretos county region, in São Paulo. Out of the 9,560 examination available, 2,964 (31%) women underwent screening. The medium distance traveled by the MU was 45 km. The medium time spent by women in the MU for completion of the questionnaire and doing the exam was 20 minutes. It was observed that 17.0% of women screened had never had the test or had not had it repeated within the last 3 years. The negative response was more common among women aged 20 to 29 years and 60 to 69 years and among women with less schooling and lower socio‐economic income (P < 0.05). MU can significantly overcome the chronic deficiency of public health system accessibility offering opportunity to these women to participate in screening programs. Diagn. Cytopathol. 2010;38:727–730. © 2009 Wiley‐Liss, Inc.     

Psychological variables of CrossFit participants: a systematic review

Sport Sciences for Health - This study aimed to review the existing literature concerning the psychological variables of CrossFit participants. This review followed the PRISMA guidelines and was...     

CO<Subscript>2</Subscript> laser irradiation enhances CaF<Subscript>2</Subscript> formation and inhibits lesion progression on demineralized dental enamel—in vitro study

This study evaluated if Carbon dioxide (CO₂) (λ 10.6 μm) laser irradiation combined with acidulated phosphate fluoride gel application (APF gel) enhances “CaF₂” uptake by demineralized enamel specimens (DES) and inhibits enamel lesion progression. Thus, two studies were conducted and DES were subjected to APF gel combined or not with CO₂ laser irradiation (11.3 or 20.0 J/cm², 0.4 or 0.7 W) performed before, during, or after APF gel application. In study 1, 165 DES were allocated to 11 groups. Fluoride as “CaF₂ like material” formed on enamel was determined in 100 DES (n?=?10/group), and the surface morphologies of 50 specimens were evaluated by scanning electron microscopy (SEM) before and after “CaF₂” extraction. In study 2, 165 DES (11 groups, n?=?15), subjected to the same treatments as in study 1, were further subjected to a pH-cycling model to simulate a high cariogenic challenge. The progression of demineralization in DES was evaluated by cross-sectional microhardness and polarized light microscopy analyses. Laser at 11.3 J/cm² applied during APF gel application increased “CaF₂” uptake on enamel surface. Laser irradiation and APF gel alone arrested the lesion progression compared with the control (p?<?0.05). Areas of melting, fusion, and cracks were observed. CO₂ laser irradiation, combined with a single APF application enhanced “CaF₂” uptake on enamel surface and a synergistic effect was found. However, regarding the inhibition of caries lesion progression, no synergistic effect could be demonstrated. In conclusion, the results have shown that irradiation with specific laser parameters significantly enhanced CaF₂ uptake by demineralized enamel and inhibited lesion progression.