Maxillary dental midline deviation in the patient perspective

Objective: This study aimed to determine aesthetic perceptions of midline deviations by orthodontic patients; influence of adjacent structures to smile in the perception of deviations; and difference between patients treated in University and in private practice. Methods: In this observational comparative cross-sectional study a smiling woman photograph was digitally modified, producing left maxillary dental midline deviations relative to facial midline. Twelve photographs were cropped in Group LCN including lips, chin and 2/3 of the nose; and group L including the lips. Non-parametric Friedman test ( = 0.05), followed by Wilcoxon test corrected by Bonferroni test ( = 0.0033) were used for multiple comparisons. Pearson correlation coefficient was used to study of the correlation and regression of the degree of smile esthetics on the midline deviations, adopting a significance level of 5%. Results: Patients were able to identify deviations from 2 mm. Among the groups of photos there was statistically significant difference in deviations of 2 and 3 mm. Comparing patients from University and private there was significant difference when comparing the photos in group LCN, without deviation and deviation of 2, 4 and 5 mm. Conclusions: Orthodontic patients are able to detect maxillary dental midline deviation from 2 mm. There was influence of viewing structures adjacent to smile in the perception of deviation for the private patients. University patients were more critical than private patients.

Objetivo: O objetivo foi avaliar a percepção estética do desvio da linha média dentária por pacientes ortodônticos; influência de estruturas adjacentes ao sorriso na percepção de desvios; e diferença de percepção entre pacientes tratados em Universidade e consultório particular. Métodos: Neste estudo comparativo observacional transversal uma fotografia de mulher sorrindo foi modificada digitalmente com desvios da linha média para a esquerda em relação à face. Doze fotografias foram recortadas para obter o grupo LCN incluindo lábios, queixo e 2/3 nariz; e grupo L incluindo lábios. O teste não paramétrico de Friedman ( = 0.05), seguido pelo de Wilcoxon, corrigido pelo teste de Bonferroni ( = 0.0033) foram utilizados para comparações múltiplas. O teste de Mann-Whitney foi aplicado para comparar grupos LCN e L, verificando a influência das estruturas adjacentes ao sorriso. O coeficiente de Pearson foi usado para correlação e regressão dos desvios sobre a estética do sorriso, adotando nível de significância de 5%.Resultados: Desvios de 2 mm foram identificados. Comparando grupos LCN e L houve diferença estatisticamente significante nos desvios de 2 e 3 mm. Entre pacientes da universidade e do consultório houve diferença significativa ao comparar fotografias no grupo LCN, sem desvio e desvios de 2, 4 e 5 mm. Conclusões: pacientes ortodônticos são capazes de detectar desvio da linha média dentária maxilar de 2 mm. Estruturas adjacentes ao sorriso influenciaram na percepção do desvio para os pacientes privados. Os pacientes da Universidade foram mais críticos do que os de consultório particular.

Protocol for the evaluation of chewing among older adults / Protocolo de avaliação da mastigação do idoso

Abstract Objectives : To evaluate the functional and physiological structures of the stomatognathic system of the oral cavity of older adults based on self-perception, comparing the same with a professional clinical evaluation, and investigating the difficulties encountered when chewing. Method : An analytical cross-sectional study with a quantitative approach was conducted with a sample of 53 older adults aged 60 to 90 years. A protocol consisting of three questionnaires was used: a sociodemographic evaluation, a self-perception based interview with 19 questions on the chewing of the older adults and a clinical evaluation containing 30 questions covering aspects of the oral cavity tissue. The self-perception and clinical evaluation scores were compared using the Mann-Whitney test and the proportions observed for each item were compared by the binomial test. Results : It was found that the self-perception of older adults did not correspond to the result of the clinical evaluation. While 31 (58.5%) reported satisfaction with chewing, 16 (30.2%) had high/very high impairment and 14(26.4%) moderate impairment, based on the results of the clinical evaluation found. Conclusion : It was found that the chewing analysis process cannot be exclusively based on the answers provided by the older adults, and assessment proved to be more accurate when combined with a clinical evaluation performed by a professional.

Resumo Objetivos : Avaliar as estruturas funcionais e fisiológicas do sistema estomatognático da cavidade bucal dos idosos diante da autopercepção, comparando-as com a avaliação clínica profissional e investigar as dificuldades encontradas para realizar sua mastigação. Método : Estudo transversal analítico de abordagem quantitativa, realizado com uma amostra de 53 idosos, idade entre 60 e 90 anos. Foi utilizado um protocolo constituído de três questionários: uma avaliação sociodemográfica, uma entrevista de autopercepção com 19 quesitos da mastigação do idoso e uma avaliação clínica contendo 30 quesitos abrangendo os aspectos teciduais da cavidade bucal. Os escores da autopercepção e da avaliação clínica foram comparados pelo teste de Mann-Whitney e as proporções observadas para cada item pelo teste binomial. Resultados : Constatou-se que a autopercepção relatada pelos idosos não correspondeu ao resultado da avaliação clínica. Enquanto 31 (58,5%) relataram satisfação com a mastigação, 16 (30,2%) possuíam comprometimento alto/muito alto e 14 (26,4%) comprometimento moderado. Conclusão : Evidenciou-se que o processo de análise da mastigação não pode ser realizado exclusivamente pelas respostas prestadas pelo idoso, sendo mais adequado quando se adiciona a etapa da avaliação clínica feita por um profissional.

Craniomaxillofacial morphology alterations in children, adolescents and adults with neurofibromatosis 1: A cone beam computed tomography analysis of a Brazilian sample

Background: Oral manifestations are common in neurofibromatosis 1 (NF1), and include jaws and teeth alterations. Our aim was to investigate the craniomaxillofacial morphology of Brazilian children, adolescents and adults with NF1 using cone beam computed tomography. Material and Methods: This study was conducted with 36 Brazilian individuals with NF1 with ages ranging from 4 to 75. The participants were submitted to anamnesis, extra and intraoral exam and cephalometric analysis using cone beam computed tomography. Height of the NF1 individuals was compared to the length of jaws and skull base. The results of the cephalometric measurements of the NF1 group were compared with a control group paired by age, gender and skin color. Results: Individuals with NF1 had lower maxillary length (p<0.0001), lower mandibular length (p<0.0001), lower skull base length (p<0.0001. In children and adolescents, the mandible was more posteriorly positioned (p=0.01), when compared with the control group. There was no association between jaws and skull base length with the height of the individuals with NF1. Conclusions: Brazilian children, adolescents and adults with NF1 have short mandible, maxilla and skull base. Moreover, children and adolescents present mandibular retrusion (AU)

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BiodentineTM is cytocompatible with human primary osteoblasts.

Calcium silicate-based materials have been widely studied due to their resemblance to, and similar applicability of, mineral trioxide aggregate (MTA). Among these, Biodentine™ (BD) was specifically designed as a "dentin replacement" material for applications such as root perforations, apexification, treatment of resorptive lesions, and as a retrograde filling material. The present study aimed to assess the in vitro response of human primary osteoblasts to BD using MTA AngelusTM as a reference material, by simultaneously analyzing three different cell viability parameters, namely mitochondrial activity, membrane integrity, and cell density. BD and MTA extracts were prepared by incubation on culture media for 24 h or 42 days after mixing. Primary human osteoblasts were exposed to extracts for 24 h, at 37oC with 5% CO2, and cell viability was evaluated by the XTT, NRU, and CVDE assays. Both materials induced cell viability levels higher than 70% when extracted for 24 h. However, when cells were exposed to extracts with increased conditioning times, MTA presented significant cytotoxic effects (p < 0.05) in comparison to the control and MTA at 24 h. After 42 days, the XTT assay identified a significant reduction in cell viability by BD when compared to the control (p<0.05), despite the fact that levels above the 70% viability cutoff were attained for biocompatible materials. It can be concluded that BD is cytocompatible with human primary osteoblasts, indicating its adequacy in direct contact with bone tissues.

Bond Strength Evaluation of Two Adhesive Systems in Fiberglass Posts Cementation

Objective: To compare the bond strength of three-step and self-etch adhesive systems with and without prior acid etching on bonding of fiberglass posts in root canals. Material and Methods: Experiments were conducted on roots of five upper molars without curvature and sectioned in a cervical-apical direction. With the aid of a highspeed turbine and diamond tips, cylindrical cavities 7 mm in depth and 1.4 mm in diameter were made in the dentine. The roots of the same tooth were used, where the retainers were cemented, thus generating three groups: Group A: Adper Scotchbond Multipurpose Plus (SBMP) + Rely X ARC; Group B: Single Bond Universal (SBU-1) + Rely X ARC, with acid etching prior to adhesive insertion; Group C: Single Bond Universal (SBU-2) + Rely X ARC. The samples were stored in a bacteriological incubator at 37ºC with 100% humidity for 48h and were subsequently cross-sectioned to obtain 3 dentine discs 1mm in thickness. Forty-five specimens were subjected to the push-out test. Results: Through the analysis of variance and Tukey's test, it was found that SBMP showed, with statistical significance (p<0.05), highest bond strength when compared with the SBU-1 and SBU-2 systems. The observed difference in the discs was located in the cervical portion. Conclusion: The three-step adhesive system had higher bond strength with the substrate than the self-etching adhesive only in the disc in the cervical portion; further, statistically, the prior application of phosphoric acid in SBU-1 did not affect its bond strength significantly.

BiodentineTM is cytocompatible with human primary osteoblasts

Abstract Calcium silicate-based materials have been widely studied due to their resemblance to, and similar applicability of, mineral trioxide aggregate (MTA). Among these, Biodentine™ (BD) was specifically designed as a "dentin replacement" material for applications such as root perforations, apexification, treatment of resorptive lesions, and as a retrograde filling material. The present study aimed to assess the in vitro response of human primary osteoblasts to BD using MTA AngelusTM as a reference material, by simultaneously analyzing three different cell viability parameters, namely mitochondrial activity, membrane integrity, and cell density. BD and MTA extracts were prepared by incubation on culture media for 24 h or 42 days after mixing. Primary human osteoblasts were exposed to extracts for 24 h, at 37oC with 5% CO2, and cell viability was evaluated by the XTT, NRU, and CVDE assays. Both materials induced cell viability levels higher than 70% when extracted for 24 h. However, when cells were exposed to extracts with increased conditioning times, MTA presented significant cytotoxic effects (p < 0.05) in comparison to the control and MTA at 24 h. After 42 days, the XTT assay identified a significant reduction in cell viability by BD when compared to the control (p<0.05), despite the fact that levels above the 70% viability cutoff were attained for biocompatible materials. It can be concluded that BD is cytocompatible with human primary osteoblasts, indicating its adequacy in direct contact with bone tissues.

Impact of gender in early structural changes of contrast induced nephropathy in rats.

INTRODUCTION: Contrast-induced nephropathy (CIN) is a major iatrogenic cause of acute kidney injury. Experimental studies have shown that intravascular injection causes intense vacuolization of the contrast agent in the proximal renal tubules cells, preceding the increase in serum creatinine, and that the female may be at a higher risk for CIN. OBJECTIVE: To study the early kidney histomorphometric changes in contrast-induced nephropathy according to the gender. METHODS: Twenty previously uninephrectomized Wistar rats were divided into 4 groups (n = 5): control males; control females; contrast exposed males; and contrast exposed females. The animals were sacrificed immediately after contrast administration and kidney tissue samples were collected for histomorphometric analysis. The research project was approved by the Research Ethics Committee of the School of Medicine of Universidade Federal Fluminense. RESULTS: There was a more intense presence of microvacuoles in proximal tubules in the rats exposed to contrast than in the control groups. Such proximal tubular vacuolation was more intensive in the female rats (p = 0.001). CONCLUSION: Proximal tubular vacuolation is a very early change in CIN and is more intensive in female than in male rats.

Impact of gender in early structural changes of contrast induced nephropathy in rats / Impacto do gênero em alterações estruturais precoces da nefropatia induzida por contraste em ratos

Abstract Introduction: Contrast-induced nephropathy (CIN) is a major iatrogenic cause of acute kidney injury. Experimental studies have shown that intravascular injection causes intense vacuolization of the contrast agent in the proximal renal tubules cells, preceding the increase in serum creatinine, and that the female may be at a higher risk for CIN. Objective: To study the early kidney histomorphometric changes in contrast-induced nephropathy according to the gender. Methods: Twenty previously uninephrectomized Wistar rats were divided into 4 groups (n = 5): control males; control females; contrast exposed males; and contrast exposed females. The animals were sacrificed immediately after contrast administration and kidney tissue samples were collected for histomorphometric analysis. The research project was approved by the Research Ethics Committee of the School of Medicine of Universidade Federal Fluminense. Results: There was a more intense presence of microvacuoles in proximal tubules in the rats exposed to contrast than in the control groups. Such proximal tubular vacuolation was more intensive in the female rats (p = 0.001). Conclusion: Proximal tubular vacuolation is a very early change in CIN and is more intensive in female than in male rats.

Resumo Introdução: A nefropatia induzida por contraste (NIC) é uma das principais causas iatrogênicas de lesão renal aguda. Estudos experimentais têm demonstrado que a injeção intravascular do agente de contraste provoca vacuolização intensa nas células dos túbulos renais proximais, que precede o aumento da creatinina sérica, e que a fêmea podem estar em maior risco de CIN. Objetivo: Estudar as primeiras mudanças histomorfométricas renais na nefropatia induzida por contraste de acordo com o gênero. Métodos: Vinte ratos Wistar anteriormente uninefrectomizados foram divididos em 4 grupos (n = 5): machos de controle; fêmeas de controle; machos expostos ao contraste e fêmeas expostas ao contraste. Os animais foram sacrificados imediatamente após a administração de contraste e amostras de tecido de rim foram coletadas para análise histomorfométrica. O projeto de pesquisa foi aprovado pelo Comitê de Ética em Pesquisa da Faculdade de Medicina da Universidade Federal Fluminense. Resultados: Houve presença mais intensa de microvacuolização em túbulos proximais nos ratos expostos ao contraste do que nos grupos de controle. Tal vacuolização tubular proximal foi mais intensa nos ratos do sexo feminino p = 0,001). Conclusão: Vacuolização do tpubulo proximal é uma mudança precoce na CIN e é mais intensa em ratos fêmeas do que em ratos machos.

Perception of midline deviations in smile esthetics by laypersons

ABSTRACT Objective: To evaluate the esthetic perception of upper dental midline deviation by laypersons and if adjacent structures influence their judgment. Methods: An album with 12 randomly distributed frontal view photographs of the smile of a woman with the midline digitally deviated was evaluated by 95 laypersons. The frontal view smiling photograph was modified to create from 1 mm to 5 mm deviations in the upper midline to the left side. The photographs were cropped in two different manners and divided into two groups of six photographs each: group LCN included the lips, chin, and two-thirds of the nose, and group L included the lips only. The laypersons performed the rate of each smile using a visual analog scale (VAS). Wilcoxon test, Student’s t-test and Mann-Whitney test were applied, adopting a 5% level of significance. Results: Laypersons were able to perceive midline deviations starting at 1 mm. Statistically significant results (p< 0.05) were found for all multiple comparisons of the values in photographs of group LCN and for almost all comparisons in photographs of group L. Comparisons between the photographs of groups LCN and L showed statistically significant values (p< 0.05) when the deviation was 1 mm. Conclusions: Laypersons were able to perceive the upper dental midline deviations of 1 mm, and above when the adjacent structures of the smiles were included. Deviations of 2 mm and above when the lips only were included. The visualization of structures adjacent to the smile demonstrated influence on the perception of midline deviation.

RESUMO Objetivo: este estudo teve por objetivo avaliar a percepção estética dos desvios da linha média dentária superior por indivíduos leigos, assim como se as estruturas adjacentes influenciam nesse julgamento. Métodos: um álbum contendo 12 fotografias frontais do sorriso de uma mulher, aleatoriamente distribuídas e com a linha média desviada digitalmente, foi avaliado por 95 indivíduos leigos. As fotografias frontais de sorriso foram modificadas para criar desvios de 1 mm a 5 mm para a esquerda na linha média superior. As fotografias foram obtidas de duas maneiras e divididas em dois grupos de seis fotografias cada: Grupo LCN, incluindo lábios, mento e dois terços do nariz; e Grupo L, incluindo apenas os lábios. Os indivíduos leigos classificaram o sorriso de acordo com uma Escala Visual Analógica (EVA). Os testes de Wilcoxon, tde Student e Mann-Whitney foram aplicados, adotando-se um nível de significância de 5%. Resultados: os leigos foram capazes de perceber desvios da linha média a partir de 1 mm. Resultados estatisticamente significativos (p < 0,05) foram encontrados para todas as múltiplas comparações dos valores nas fotografias do Grupo LCN e para quase todas as comparações nas fotografias do Grupo L. As comparações entre as fotografias dos grupos LCN e L mostraram valores estatisticamente significativos (p < 0,05) quando o desvio foi de 1 mm. Conclusões: os indivíduos leigos foram capazes de perceber os desvios da linha média de 1 mm; e acima desses, quando estruturas adjacentes ao sorriso apareciam nas fotografias. Desvios de 2 mm ou mais foram percebidos apenas quando os lábios apareciam nas fotografias; a visualização das estruturas adjacentes ao sorriso pareceu ter influência sobre a percepção dos desvios da linha média.

Immunoexpression of cleaved caspase-3 shows lower apoptotic area indices in lip carcinomas than in intraoral cancer.

OBJECTIVE: This study aimed to evaluate apoptosis by assessing cleaved caspase-3 immunoexpression in hyperplastic, potentially malignant disorder (PMD), and malignant tumors in intraoral and lower lip sites. MATERIAL AND METHODS: A retrospective study using paraffin blocks with tissues from patients with inflammatory fibrous hyperplasia (IFH), actinic cheilitis, oral leukoplakia, lower lip and intraoral squamous cell carcinoma (SCC) was performed. The tissues were evaluated by immunohistochemical analysis with anti-cleaved caspase-3 antibody. Apoptotic area index was then correlated with lesion type. RESULTS: From 120 lesions assessed, 55 (46%) were cleaved caspase-3-positive. The SCC samples (n=40) had the highest apoptotic area indices (n=35; 87.5%). Significant differences were detected between SCCs and PMDs (p=0.0003), as well as SCCs and IFHs (p=0.001), regarding caspase-3 immunopositivity. Carcinomas of the lower lip had lower apoptotic area indices than intraoral cancer (p=0.0015). CONCLUSIONS: Cleaved caspase-3 immunoexpression showed differences in oral SCCs and PMDs and demonstrated a distinct role of apoptosis in carcinogenesis of intraoral and lower lip cancer. In future, the expression of cleaved caspase-3 with other target molecules in oral cancer may be helpful in delineating the prognosis and treatment of these tumors.

Immunoexpression of cleaved caspase-3 shows lower apoptotic area indices in lip carcinomas than in intraoral cancer

ABSTRACT Objective This study aimed to evaluate apoptosis by assessing cleaved caspase-3 immunoexpression in hyperplastic, potentially malignant disorder (PMD), and malignant tumors in intraoral and lower lip sites. Material and Methods A retrospective study using paraffin blocks with tissues from patients with inflammatory fibrous hyperplasia (IFH), actinic cheilitis, oral leukoplakia, lower lip and intraoral squamous cell carcinoma (SCC) was performed. The tissues were evaluated by immunohistochemical analysis with anti-cleaved caspase-3 antibody. Apoptotic area index was then correlated with lesion type. Results From 120 lesions assessed, 55 (46%) were cleaved caspase-3-positive. The SCC samples (n=40) had the highest apoptotic area indices (n=35; 87.5%). Significant differences were detected between SCCs and PMDs (p=0.0003), as well as SCCs and IFHs (p=0.001), regarding caspase-3 immunopositivity. Carcinomas of the lower lip had lower apoptotic area indices than intraoral cancer (p=0.0015). Conclusions Cleaved caspase-3 immunoexpression showed differences in oral SCCs and PMDs and demonstrated a distinct role of apoptosis in carcinogenesis of intraoral and lower lip cancer. In future, the expression of cleaved caspase-3 with other target molecules in oral cancer may be helpful in delineating the prognosis and treatment of these tumors.

DENGUE DURING PREGNANCY: ASSOCIATION WITH LOW BIRTH WEIGHT AND PREMATURITY.

The aim of this study was to evaluate the effects of dengue virus infection during pregnancy and its correlation with low birth weight, prematurity, and asphyxia. A non-concurrent cohort study reveals the association of dengue during pregnancy with prematurity and low birth weight, when birth occurred during the maternal-fetal viremia period (p = 0.016 and p < 0.0001, respectively).

Perception of midline deviations in smile esthetics by laypersons.

OBJECTIVE:: To evaluate the esthetic perception of upper dental midline deviation by laypersons and if adjacent structures influence their judgment. METHODS:: An album with 12 randomly distributed frontal view photographs of the smile of a woman with the midline digitally deviated was evaluated by 95 laypersons. The frontal view smiling photograph was modified to create from 1 mm to 5 mm deviations in the upper midline to the left side. The photographs were cropped in two different manners and divided into two groups of six photographs each: group LCN included the lips, chin, and two-thirds of the nose, and group L included the lips only. The laypersons performed the rate of each smile using a visual analog scale (VAS). Wilcoxon test, Student's t-test and Mann-Whitney test were applied, adopting a 5% level of significance. RESULTS:: Laypersons were able to perceive midline deviations starting at 1 mm. Statistically significant results (p< 0.05) were found for all multiple comparisons of the values in photographs of group LCN and for almost all comparisons in photographs of group L. Comparisons between the photographs of groups LCN and L showed statistically significant values (p< 0.05) when the deviation was 1 mm. CONCLUSIONS:: Laypersons were able to perceive the upper dental midline deviations of 1 mm, and above when the adjacent structures of the smiles were included. Deviations of 2 mm and above when the lips only were included. The visualization of structures adjacent to the smile demonstrated influence on the perception of midline deviation.

DENGUE DURING PREGNANCY: ASSOCIATION WITH LOW BIRTH WEIGHT AND PREMATURITY

The aim of this study was to evaluate the effects of dengue virus infection during pregnancy and its correlation with low birth weight, prematurity, and asphyxia. A non-concurrent cohort study reveals the association of dengue during pregnancy with prematurity and low birth weight, when birth occurred during the maternal-fetal viremia period (p = 0.016 and p < 0.0001, respectively).

A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests.

The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) 25-08 and Reciproc (VDW, Munich, Germany) 25-08 instruments. A total of 60 nickel-titanium (NiTi) instruments (30 Reciproc and 30 WaveOne) from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine. Static and dynamic cyclic fatigue testing was conducted using a custom-made device. For the static and dynamic tests, a cast Ni-Cr-Mo-Ti alloy metal block with an artificial canal measuring 1.77 mm in diameter and 20.00 mm in total length was used. A scanning electron microscope was used to determine the type of fracture. Statistical analyses were performed on the results. The WaveOne instrument was less flexible than the Reciproc (p < 0.05). The Reciproc instrument showed better resistance in the static and dynamic cyclic fatigue tests (p < 0.05). The transverse cross-section and geometry of the instruments were important factors in their resistance to bending and cyclic fracture. Both of the instruments showed ductile-type fracture characteristics. It can be concluded that the Reciproc 25-08 instrument was more resistant to static and dynamic cyclic fatigue than the WaveOne 25-08 instrument, while the WaveOne 25-08 instrument was less flexible. Bending and resistance to cyclic fracture were influenced by the instruments' geometries and transverse cross-sections. Both of the instruments showed ductile-type fracture characteristics.

A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests

The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) 25-08 and Reciproc (VDW, Munich, Germany) 25-08 instruments. A total of 60 nickel-titanium (NiTi) instruments (30 Reciproc and 30 WaveOne) from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine. Static and dynamic cyclic fatigue testing was conducted using a custom-made device. For the static and dynamic tests, a cast Ni-Cr-Mo-Ti alloy metal block with an artificial canal measuring 1.77 mm in diameter and 20.00 mm in total length was used. A scanning electron microscope was used to determine the type of fracture. Statistical analyses were performed on the results. The WaveOne instrument was less flexible than the Reciproc (p < 0.05). The Reciproc instrument showed better resistance in the static and dynamic cyclic fatigue tests (p < 0.05). The transverse cross-section and geometry of the instruments were important factors in their resistance to bending and cyclic fracture. Both of the instruments showed ductile-type fracture characteristics. It can be concluded that the Reciproc 25-08 instrument was more resistant to static and dynamic cyclic fatigue than the WaveOne 25-08 instrument, while the WaveOne 25-08 instrument was less flexible. Bending and resistance to cyclic fracture were influenced by the instruments’ geometries and transverse cross-sections. Both of the instruments showed ductile-type fracture characteristics.

Frictional resistance of self-ligating versus conventional brackets in different bracket-archwire-angle combinations.

OBJECTIVE: To compare the influence of archwire material (NiTi, beta-Ti and stainless steel) and brackets design (self-ligating and conventional) on the frictional force resistance. MATERIAL AND METHODS: Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek) with three (0, 5, and 10 degrees) slot angulation attached with elastomeric ligatures (TP Orthodontics) were tested. All brackets were tested with archwire 0.019"x0.025" nickel-titanium, beta-titanium, and stainless steel (Unitek/3M). The mechanical testing was performed with a universal testing machine eMIC DL 10000 (eMIC Co, Brazil). The wires were pulled from the bracket slots at a cross-head speed of 3 mm/min until 2 mm displacement. RESULTS: Self-ligating brackets produced significantly lower friction values compared with those of conventional brackets. Frictional force resistance values were directly proportional to the increase in the bracket/ wire angulation. With regard to conventional brackets, stainless steel wires had the lowest friction force values, followed by nickel-titanium and beta-titanium ones. With regard to self-ligating brackets, the nickel-titanium wires had the lowest friction values, significantly lower than those of other materials. CONCLUSION: even at different angulations, the self-ligating brackets showed significantly lower friction force values than the conventional brackets. Combined with nickel-titanium wires, the self-ligating brackets exhibit much lower friction, possibly due to the contact between nickel-titanium clips and wires of the same material.

Frictional resistance of self-ligating versus conventional brackets in different bracket-archwire-angle combinations

Objective: To compare the influence of archwire material (NiTi, beta-Ti and stainless steel) and brackets design (self-ligating and conventional) on the frictional force resistance. Material and Methods: Two types of brackets (self-ligating brackets - Smartclip, 3M/Unitek - and conventional brackets - Gemini, 3M/Unitek) with three (0, 5, and 10 degrees) slot angulation attached with elastomeric ligatures (TP Orthodontics) were tested. All brackets were tested with archwire 0.019"x0.025" nickel-titanium, beta-titanium, and stainless steel (Unitek/3M). The mechanical testing was performed with a universal testing machine eMIC DL 10000 (eMIC Co, Brazil). The wires were pulled from the bracket slots at a cross-head speed of 3 mm/min until 2 mm displacement. Results: Self-ligating brackets produced significantly lower friction values compared with those of conventional brackets. Frictional force resistance values were directly proportional to the increase in the bracket/ wire angulation. With regard to conventional brackets, stainless steel wires had the lowest friction force values, followed by nickel-titanium and beta-titanium ones. With regard to self-ligating brackets, the nickel-titanium wires had the lowest friction values, significantly lower than those of other materials. Conclusion: even at different angulations, the self-ligating brackets showed significantly lower friction force values than the conventional brackets. Combined with nickel-titanium wires, the self-ligating brackets exhibit much lower friction, possibly due to the contact between nickel-titanium clips and wires of the same material. .

Organochlorine compound levels in fertile and infertile women from Rio de Janeiro, Brazil.

OBJECTIVE: The aim of the study was quantify organochlorine compounds in women seeking for infertility treatment (n = 15) and in spontaneously pregnant ones (n = 21). MATERIALS AND METHODS: A questionnaire was applied regarding lifestyle, occupational and reproductive history. Blood samples were collected from both groups. RESULTS: From the pesticides studied, pp'DDE was detected in 100% of infertile women, at higher mean levels than in pregnant women (3.02 mcg/L vs. 0.88 mcg/L; p = 0.001; power of 69%), without correlation with the etiology of infertility. Levels of the polychlorinated biphenyls (PCBs) were low, with positive samples in 100% in the infertile women for PCBs 138, 153, 180, while in pregnant women, they were 85.7% for congeners 138 and 153. Only PCB180 showed significance, with frequency of 71.4% (p = 0.019). CONCLUSIONS: The risk factors for female infertility were: age, consumption of untreated water and of canned foods. Exposure to the most prevalent organochlorine compounds described in literature was confirmed in the study, indicating that pp'DDE may adversely influence female fertility.

Organochlorine compound levels in fertile and infertile women from Rio de Janeiro, Brazil / Níveis de substâncias organocloradas em mulheres férteis e inférteis do Rio de Janeiro, Brasil

OBJECTIVE: The aim of the study was quantify organochlorine compounds in women seeking for infertility treatment (n = 15) and in spontaneously pregnant ones (n = 21). MATERIALS AND METHODS: A questionnaire was applied regarding lifestyle, occupational and reproductive history. Blood samples were collected from both groups. RESULTS: From the pesticides studied, pp'DDE was detected in 100% of infertile women, at higher mean levels than in pregnant women (3.02 mcg/L vs. 0.88 mcg/L; p = 0.001; power of 69%), without correlation with the etiology of infertility. Levels of the polychlorinated biphenyls (PCBs) were low, with positive samples in 100% in the infertile women for PCBs 138, 153, 180, while in pregnant women, they were 85.7% for congeners 138 and 153. Only PCB180 showed significance, with frequency of 71.4% (p = 0.019). CONCLUSIONS: The risk factors for female infertility were: age, consumption of untreated water and of canned foods. Exposure to the most prevalent organochlorine compounds described in literature was confirmed in the study, indicating that pp'DDE may adversely influence female fertility.

OBJETIVO: O estudo teve como objetivo quantificar as substâncias organocloradas em mulheres buscando tratamento para infertilidade (n = 15) e que espontaneamente engravidaram (n = 21). MATERIAIS E MÉTODOS: Foi aplicado questionário considerando estilo de vida, história ocupacional e reprodutiva. Amostras de sangue foram obtidas em ambos os grupos. RESULTADOS: Dos pesticidas, pp'DDE foi detectado em 100% das inférteis, com níveis maiores que nas grávidas (3,02 mcg/L vs. 0,88 mcg/L; p = 0,001; poder 69%), sem correlação na etiologia da infertilidade. Os níveis de detecção das bifenilas policloradas (PCBs) foram baixos, com 100% de positividade das amostras nas inférteis para os PCBs 138, 153, 180, e de 85,7% nas grávidas para os congêneres 138 e 153. Apenas PCB180 mostrou significância na frequência de 71,4% (p = 0,019). CONCLUSÕES: Os fatores de risco para infertilidade feminina foram: idade, consumo de água não tratada e alimentos enlatados. A exposição aos organoclorados mais prevalentes descritos na literatura foi confirmada no estudo, indicando que pp'DDE pode influenciar adversamente a fertilidade feminina.