Most bowel cancer symptoms do not indicate colorectal cancer and polyps: a systematic review

<p>Abstract</p> <p>Background</p> <p>Bowel symptoms are often considered an indication to perform colonoscopy to identify or rule out colorectal cancer or precancerous polyps. Investigation of bowel symptoms for this purpose is recommended by numerous clinical guidelines. However, the evidence for this practice is unclear. The objective of this study is to systematically review the evidence about the association between bowel symptoms and colorectal cancer or polyps.</p> <p>Methods</p> <p>We searched the literature extensively up to December 2008, using MEDLINE and EMBASE and following references. For inclusion in the review, papers from cross sectional, case control and cohort studies had to provide a 2×2 table of symptoms by diagnosis (colorectal cancer or polyps) or sufficient data from which that table could be constructed. The search procedure, quality appraisal, and data extraction was done twice, with disagreements resolved with another reviewer. Summary ROC analysis was used to assess the diagnostic performance of symptoms to detect colorectal cancer and polyps.</p> <p>Results</p> <p>Colorectal cancer was associated with rectal bleeding (AUC 0.66; LR+ 1.9; LR- 0.7) and weight loss (AUC 0.67, LR+ 2.5, LR- 0.9). Neither of these symptoms was associated with the presence of polyps. There was no significant association of colorectal cancer or polyps with change in bowel habit, constipation, diarrhoea or abdominal pain. Neither the clinical setting (primary or specialist care) nor study type was associated with accuracy.</p> <p>Most studies had methodological flaws. There was no consistency in the way symptoms were elicited or interpreted in the studies.</p> <p>Conclusions</p> <p>Current evidence suggests that the common practice of performing colonoscopies to identify cancers in people with bowel symptoms is warranted only for rectal bleeding and the general symptom of weight loss. Bodies preparing guidelines for clinicians and consumers to improve early detection of colorectal cancer need to take into account the limited value of symptoms.</p

Influence of fiber-post translucency on the degree of conversion of a dual-cured resin cement

This study evaluated the degree of conversion of one dual-cured resin cement when used to lute fiber posts with different translucencies. To measure the degree of conversion, polyvinylsiloxane molds were prepared to simulate root canals. The posts, Aestheti-Post or Light-Post, were cemented in these molds and, after photoactivation, were removed to obtain the resin cement spectrum by FT-Raman spectroscopy. Spectra were acquired at three depths: superficial, medium, and deep. For Light-Post, the resin cement at deep depth showed the lowest degree of conversion and no significant difference in degree of conversion was found between the other depths. For Aestheti-Post, the superficial depth presented a higher degree of conversion values than those in the medium and deep depths, which were not significantly different from each other. Light-Post exhibited a higher degree of conversion than that of Aestheti-Post only at medium depth. Light-Post effectiveness regarding the degree of conversion is dependent on the depth.33330330

Combined effects of carbon dioxide laser and fluoride on demineralized primary enamel: An in vitro study

This in vitro study aimed at evaluating the efficacy of a CO2 laser (10.6 mu m) alone or combined with acidulated phosphate fluoride (APF) on the inhibition of lesion progression in primary enamel. The specimens were treated with/without CO2 laser and/or APF and submitted to pH cycling. Microhardness analysis was performed and the enamel mineral loss values were obtained. The groups treated with laser and/or APF presented lower mineral loss when compared to the control group (p < 0.05). Laser irradiation alone or combined with APF decreased lesion progression in primary enamel. However, the combined treatment did not show any significant additional effect. Copyright (c) 2007 S. Karger AG, Basel.411747

Physical and Compositional Changes on Demineralized Primary Enamel Induced by CO2 Laser

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Objective: This in vitro study aimed to evaluate the physical and chemical changes promoted by a CO2 laser at 10.6-mu m wavelength on primary dental enamel with artificial caries-like lesions. Background Data: Several previous investigations have shown that enamel can be modified by CO2 laser to obtain a caries-preventive effect, but the specific mechanism remains uncertain. Materials and Methods: Twenty-seven primary molars were randomly assigned to three groups as follows: control, carious, and laser (n = 9). The specimens from the carious and laser groups were demineralized and treated with or without CO2 laser, according to the group. Enamel surface changes after treatments were monitored using Fourier transform Raman spectroscopy and scanning electron microscopy (SEM). Results: The Raman spectra showed a statistically significant reduction of mineral content in carious and laser groups when compared to control group. Additionally, carbonate content was reduced in irradiated specimens when compared to the other groups. No physical change was observed in specimens evaluated by SEM. Conclusion: The results suggest that CO2 laser irradiation may reduce the carbonate content of enamel, which is likely to make this substrate more acid-resistant.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.274585590Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [00=097028, 01=14384-8]CNPq [302393=2003-0

Chemical, morphological and thermal effects of 10.6-mu um CO2 laser on the inhibition of enamel demineralization

Studies have shown that enamel can be modified by pulsed CO2 laser to form a more acid-resistant substrate. This study evaluated the effects of a 10.6-mu m CO2 laser on enamel surface morphology and chemical composition as well as monitored intrapulpal temperature changes during irradiation. Human teeth were irradiated with fluences of 1.5-11.5 J/cm(2), and pulpal thermal as well as chemical and morphological modifications on enamel were assessed. The teeth were submitted to a pH-cycling model, and the mineral loss was determined by means of cross-sectional microhardness. For all irradiated groups, intrapulpal temperature changes were below 3 degrees C. FT-Raman spectroscopy and scanning electron microscopy indicated that fluences as low as 6.0 J/cm(2) were sufficient to induce chemical and morphological changes in enamel. Then, for fluences reaching or exceeding 10.0 J/cm(2), laser-induced inhibitory effects on demineralization were observed. It was thus concluded that laser energy density in the range of 10.0 and 11.5 J/cm(2) could be applied to dental enamel in order to produce chemical and morphological changes and reduce the acid reactivity of enamel without compromising the pulp vitality.25345546

Physicochemical changes in enamel submitted to pH cycling and bleaching treatment

Evania Eskelsen,1 Anderson Catelan,1 Nat&aacute;lia Maria Aparecida Pinto Hernades,2 Lu&iacute;s Eduardo Silva Soares,3 Andrea N&oacute;brega Cavalcanti,4 Fl&aacute;vio Henrique Baggio Aguiar,2 Priscila Christiane Suzy Liporoni1 1Department of Dentistry, University of Taubat&eacute;, Taubat&eacute;, S&atilde;o Paulo, Brazil; 2Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, S&atilde;o Paulo, Brazil; 3Laboratory of Biomedical Vibrational Spectroscopy, Research and Development Institute, University of Vale do Para&iacute;ba, S&atilde;o Jos&eacute; dos Campos, S&atilde;o Paulo, Brazil; 4Department of Restorative Dentistry, School of Medicine and Public Health of Bahia and Federal University of Bahia, Salvador, Bahia, Brazil Objective: The purpose of this study was to assess the hardness, mineral content, surface roughness, and micromorphology of sound and slightly demineralized enamels, before and after bleaching procedure using 10% carbamide peroxide.Methods: Sixty bovine dental blocks were randomly divided into the following two groups: 30 slabs were submitted to three cycles of pH and 30 slabs were noncycled. Hardness (n=10) was measured using the microhardness tester with Knoop indenter under a 50&nbsp;g load for 5&nbsp;seconds. The calcium/phosphate (Ca/P) ratio (n=10) was obtained using a micro-energy-dispersive X-ray fluorescence (&mu;-EDXRF) spectrometer. The measurement of roughness average (n=10) was performed using a surface roughness tester. Specimens were bleached 6&nbsp;hours/day during 21&nbsp;days, and then, physicochemical properties were re-evaluated. Two additional specimens were carried out to evaluate surface micromorphology using the scanning electron microscopy. Data were statistically analyzed by ANOVA and Tukey&rsquo;s test (&alpha;=0.05).Results: Sound and slightly demineralized enamels showed no difference in Ca/P ratio after dental bleaching according to the &micro;-EDXRF analysis, but the Ca/P ratio decreased after bleaching for slightly demineralized enamel. Bleaching treatment decreased the hardness and increased the surface roughness, causing micromorphology alterations.Conclusion: Therefore, bleaching procedure promoted change in bovine enamel surface and increased the demineralization of slightly demineralized enamel but not affected the mineral content of sound enamel. Keywords: tooth bleaching, dental enamel, chemical properties, pH cycling, microhardness, roughnes

Mineral distribution and CLSM analysis of secondary caries inhibition by fluoride/MDPB-containing adhesive system after cariogenic challenges

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Objective: To evaluate the inhibition zone formation (IZ) and mineral distribution along the interface of adhesive systems either containing fluoride and antibacterial primer or not, after chemical and biological artificial caries challenges. Methods: Forty-eight third molars were used. Artificial caries was developed with S. mutans in a 4 mm x 4 mm area of occlusal dentin surface. Carious dentin was removed and cavities were restored with Adper Scotchbond Multi-Purpose (SBM) and Clearfil Protect Bond (CPB) (n = 24). Samples were submitted to secondary caries development by chemical (C) (acidic gel) or biological (B) (S. mutans culture) methods for 5 days. Four groups were tested (n = 12): (1) SC (SBM + C); (2) SB (SBM + B); (3) CC (CPB + C); (4) CB (CPB + B). The IZ and outer lesion (OL) formations were analyzed by confocal. laser scanning microscopy (CLSM). The distribution of calcium (Ca) and phosphorus (P) content along the interface was analyzed by micro X-ray fluorescence spectrometer by energy-dispersive (mu EDX). Results: The frequency of IZ formation and mean values of IZ thickness differed among the groups. The CC group presented the lowest OL depth. mu EDX analysis showed that CPB had the highest mineral loss by the biological method, but the lowest mineral loss by the chemical method. SC and SB groups showed intermediate values of mineral loss. Conclusion: The mineral loss along the dentin/restoration inter-face was affected by the artificial caries method, and hybrid layer formation by adhesive systems used. The adhesive system containing fluoride and antibacterial primer did not prevent secondary caries formation. (C) 2008 Elsevier Ltd. All rights reserved.374307314Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [05/57268-9

Effects of Combined Use of Light Irradiation and 35% Hydrogen Peroxide for Dental Bleaching on Human Enamel Mineral Content

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Objective: The objective of this study was to evaluate the effects of the combined use of light irradiation (LIR, halogen light, or LED/diode laser) and 35% hydrogen peroxide (35% HP) on human enamel mineral content. Background Data: The use of high-intensity light has been indicated for acceleration of the rate of chemical bleaching; however, it is not known whether LIR can promote additional effects on enamel surfaces during the bleaching. Materials and Methods: One hundred enamel samples were obtained from third molars and randomly divided into 10 groups (n = 10). The control group (CG) remained untreated. Three whitening products were used: Whiteness HP Maxx, Pola Office, and Opalescence Xtra. Bleaching consisted of one session, and the products were applied three times to each specimen for 10 min each. The products were subjected, or not, to LIR during treatment with halogen light or LED/diode laser. The mineral concentration of enamel was determined before and after treatments using an FT-Raman spectroscope (FT-RS), and the amount of calcium lost from the bleached enamel surfaces was quantified with an atomic absorption spectrometer (AAS). Results: FT-RS results showed a decreased mineral content after all treatments, with the exception of Pola Office when irradiated with LED/diode laser and the CG. The losses of calcium detected for Pola Office and Opalescence Xtra were similar for the three situations (without or with light irradiations), whereas for Whiteness HP Maxx the lowest calcium loss was detected without LIR. Conclusion: Most of the bleaching treatments investigated, in combination with LIR or not, can reduce the mineral content of enamel surface. LIR increased the calcium loss for Whiteness HP Maxx; no effects were observed for Pola Office and Opalescence Xtra.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.284533538Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [05/60696-2