Psychometric analysis of the Brazilian-version Kidscreen-27 questionnaire.

BACKGROUND: The objective of this study was to verify the reliability, discriminatory power and construct validity of the Kidscreen-27 questionnaire in Brazilian adolescents. METHODS: Adolescents that participated of the pilot study (210 adolescents; 52.9% boys; 13.7 years old) and of the baseline (816 participants; 52.7% girls; 13.1 years old) of the Movimente Project in 2016/2017 composed the sample of the present study. This project was carried out in six public schools in the city of Florianópolis, Santa Catarina, Brazil. Test-retest reproducibility was assessed by the intraclass correlation coefficient and Gwet coefficient; internal consistency through McDonald's Omega; Hankins' Delta G coefficient verified the scale's discriminatory power and; confirmatory factor analysis to assess construct validity. RESULTS: Reproducibility values ranged from 0.71 to 0.78 for the dimensions (ICC), and ranged from 0.60 to 0.83 for the items (Gwet). McDonald's Ômega (0.82-0.91) for internal consistency measures. Discriminatory power ranging from 0.94 for the dimension Social Support and Friends to 0.98 for Psychological Well-Being. The factorial loads were > 0.40, except for item 19 (0.36). The fit quality indicators of the model were adequate (X2[df] = 1022.89 [311], p < 0.001; RMSEA = 0.053 (0.049-0.087); CFI = 0.988; TLI = 0.987), confirming the five-factor structure originally proposed. CONCLUSIONS: The Brazilian-version Kidscreen-27 achieved good levels of reproducibility, internal consistency, discriminatory power and construct validity. Its use is adequate to measure the health-related quality of life of adolescents in the Brazilian context.

Mediating role of screen media use on adolescents' total sleep time: A cluster-randomized controlled trial for physical activity and sedentary behaviour.

BACKGROUND: The present study aimed to analyse the effect of an intervention for increasing physical activity (PA) and reducing sedentary time on adolescents' total sleep time (TST) and to examine whether the effect on adolescents' TST was mediated by the intervention changes on screen-based sedentary time. METHODS: This study was a school-based cluster-randomized controlled trial conducted with Brazilian adolescents in Grades 7 to 9 (in 2017). Three schools participated in each of the intervention group (IG) and control group (CG). The intervention involved the following three strategies designed to increase PA and reduce sedentary time: (a) teacher training, (b) environmental improvements, and (c) health educational component. TST and screen-based sedentary time (television use, cell phone use, playing on computer/video game, and computer use that is not for gaming purposes) on weekdays and weekends were assessed using a standardized questionnaire. Generalized linear mixed models were conducted to verify the effect of the intervention on TST. Mediation analyses were used to examine the mediator role of changes in screen-based sedentary time in the relationship between the intervention and TST. RESULTS: Overall, 597 students participated in this study (mean age: 13.0 ± 1.0 years; IG: n = 351; CG: n = 246). The intervention had no effect on TST on weekdays and weekends. Adolescents in the IG were more likely to report ≤2 hr of television viewing per day on weekdays at follow-up. Mediated effects by screen media use were not significant. CONCLUSIONS: The school-based intervention for increasing PA and reducing sedentary time had no effect on adolescents' TST.

Implementing DICOM structured reporting in a large-scale telemedicine network.

INTRODUCTION: Large-scale asynchronous telemedicine networks can offer a unique opportunity for the acquisition of detailed epidemiological information if the data are acquired and handled in an appropriate way. In this work, an approach is presented for the integration of medical reports in the Digital Imaging and Communications in Medicine (DICOM) Structured Reporting standard in telemedicine networks using structured vocabularies. MATERIALS AND METHODS: The use of these structured vocabularies is extended beyond radiology, and a case study in telecardiology is presented. The approach was applied in the context of a real-world statewide public telemedicine network; nowadays on average 470 written electrocardiographic structured reports daily are being performed. Cardiologists provided more than 220,000 written structured reports, and these reports are stored into a central database. RESULTS: This study was performed during a 12-month period, and it was possible to examine possible associations between a list of co-morbidities and cardiac risk factors with a diagnosis that indicates the presence of cardiac ischemia, cardiac injury, or possible necrosis by using DICOM Structured Reporting. Our application is responsible for coordinating the process of issuance of reports through various technologies and devices. The system works as a library in an HTTP server, which accesses information from studies in DICOM format from the database and from structured vocabularies. CONCLUSIONS: Results indicate that traceability of morbidity, diagnoses, and patient clinical information can be achieved, resulting in an efficient data mining-friendly framework. A multidevice application for Web-based and smartphone-based platforms showed that it is a viable solution for applying the DICOM Structured Reporting standard in telemedicine networks.

Association between dental caries and molar-incisor hypomineralisation in first permanent molars: A hierarchical model.

OBJECTIVE: To assess whether the prevalence of dental caries is associated with the presence of molar-incisor hypomineralisation (MIH) in first permanent molars (FPMs). METHODS: A cross-sectional study was conducted with a sample of 5368 FPMs from 1342 children aged 8-10 years from Florianopolis, Brazil. Dental caries was evaluated with the Decayed, Missing and Filled Teeth (DMFT) index and MIH was assessed according to the European Academy of Paediatric Dentistry (EAPD) criteria. The sociodemographic data were obtained with a questionnaire sent to caregivers. A hierarchical repeated measures Poisson regression, considering dependency among observations, was performed, since the unit of analysis was the tooth. RESULTS: The presence of MIH was associated with a 6.15 times higher prevalence of dental caries in FPMs (PR: 6.15; 95%CI: 4.18-9.04). A monthly family income ≤2 minimum wages and the caries experience in the primary teeth were also significantly associated with greater prevalence rates of dental caries in FPMs. CONCLUSION: The presence of MIH showed a significant association with the prevalence of dental caries in FPMs. Thus, dentists should be alert to cases of MIH. Once the condition is detected, preventive measures should be taken to prevent enamel breakdown and the development of dental caries lesions.

Assessment of the Brazilian Version of the Epworth Sleepiness Scale Using Item Response Theory: A Psychometric Study.

There seems to be a consensus that adolescents worldwide are not getting enough sleep. This study aimed to evaluate the psychometric properties of the Epworth Sleepiness Scale (ESS) in adolescents using the item response theory. A psychometric study was conducted with 2206 adolescents aged 18 and 19 years in the city of São Luís, Maranhão, Brazil. The dimensionality of the ESS was assessed by principal component analysis. A Samejima's graded response model (SGRM) was fitted to it. The findings of this study showed a good internal consistency and the unidimensionality of the ESS. Considering the latent trait continuum, we obtained three levels, with anchor items. For the item 'Sitting still in a public place', the adolescents presented a small possibility of dozing in level 1, and a medium and great possibility in level 2. The item 'Sitting around talking to someone' presented small, medium, and great possibilities of dozing in level 3. The ESS with five items showed satisfactory psychometric properties. In addition, the results from the SGRM showed that adolescents with high levels of sleepiness are likely to nod off or sleep sitting up while talking to someone. This study allows us to understand excessive daytime sleepiness in adolescents.

Obesogenic Clusters Associated with Weight Status in Brazilian Adolescents of the Movimente School-Base Intervention.

BACKGROUND: the relationship between behavior clusters and weight status, mainly in low- and middle-income countries, remains unclear. This study aimed to examine the association between profiles of physical activity (PA), diet and sedentary behavior (SB) with weight status in adolescents from a southern Brazilian city, according to sex. METHODS: data from the Movimente Intervention study were analyzed (n = 812 / mean age 13.0 years (sd 1.04). Data on SB hours per day, PA minutes per week and weekly consumption frequencies of fruits, vegetables, salty snacks, candies and soda were self-reported on the validated Movimente questionnaire. Classes of healthy and unhealthy behaviors were derived by latent class analysis. Logistic regression analysis was used to estimate the associations between adolescents' weight status and classes. RESULTS: two classes were identified for the whole sample and for boys and girls. All classes had high probabilities of engaging high time in SB. Male adolescents in the unhealthy class had low probabilities of being active and high probability of consuming a low-quality diet. In contrast, girls' healthiest profile presented lower probabilities of being active compared to boys' healthiest profiles. No association was found between weight status and classes. CONCLUSION: All classes had at least one unhealthy behavior, for both the whole sample, and for girls and boys. Girls' profiles were unhealthier compared to boys' profiles. Hence, it is recommended that intervention strategies to change behaviors need to be distinct according to sex, targeting more than one obesogenic behavior at the same time.

Mat pilates method improve postural alignment women undergoing hormone therapy adjunct to breast cancer treatment. Clinical trial.

The purpose of the study is to analyze the effects of a mat Pilates intervention on the postural alignment and balance of breast cancer women receiving hormone therapy. A two-arm randomized clinical trial included 34 breast cancer survivors divided randomly between a mat Pilates group (n = 18), that performed 16 weeks of mat Pilates exercises, and a control group (n = 16), who were invited to maintain their daily routine activities and received three educational sessions. Data collection occurred at baseline and at post-intervention time. The postural alignment was assessed using the Postural Assessment Software (SAPO) and the balance was assessed by the MINIBESTest. When the two-way ANOVA was performed on postural alignment results, a significant statistical difference was found in the angle between acromions and the anterior-superior iliac spines of the mat Pilates group (p = 0.036). When compared to the post-intervention period, the mat Pilates method had an improved horizontal alignment of the anterior-superior iliac spines (p = 0.039) and vertical alignment of the acromion head on the right side (p = 0,016). Also, the participants of the Pilates group showed a significant statistical difference in the balance (p = 0.034). The control group had an improved vertical trunk alignment on the left side (p = 0,048). The control group and the mat Pilates method group improved in some aspects, however the mat Pilates method was effective in improving the postural alignment and the balance of breast cancer survivors receiving hormone therapy and may be recommended in oncological rehabilitation as a type of complementary therapy.

Smoking among industrial workers in Brazil: association with sociodemographic factors, alcohol consumption, and stress levels.

OBJECTIVE: To determine the prevalence of smoking, as well as its association with sociodemographic factors, alcohol consumption, and stress levels, among industrial workers in Brazil. METHODS: This was a nationwide survey, conducted in 24 capitals in Brazil through the application of a pre-tested questionnaire. The response to the question "What is your smoking status?" was the outcome variable. To determine the associations, we performed Poisson regression analyses in which the inputs were blocks of variables: block 1 (age and marital status); block 2 (level of education and gross family income); block 3 (geographic region); and block 4 (alcohol consumption and stress level). All analyses were stratified by gender. RESULTS: The sample consisted of 47,328 workers ≥ 18 years of age, of whom 14,577 (30.8%) were women. The prevalence of smoking was 13.0% (15.2% in men and 7.9% in women). Advancing age, alcohol consumption, and a high stress level were positively associated with smoking. A lower risk of smoking was associated with being married, having a higher level of education, and living in the northeastern region of the country (versus the southern region). CONCLUSIONS: The prevalence of smoking was greater in men than in women. Alcohol consumption and high stress levels appear to promote smoking.

Anthropometric measurements in the elderly of Havana, Cuba: age and sex differences.

OBJECTIVE: We present selected anthropometric data, specific for sex and age group, from a representative sample of elderly subjects living in Havana, Cuba. METHODS: This was a cross-sectional, population-based household survey. A total of 1905 subjects (1197 women and 708 men, > or = 60 y of age) were examined between 1999 and 2000 as selected by probabilistic sampling. Data were presented as means and percentiles for body mass; height or stature; body mass index; waist, arm, and calf circumferences; triceps skinfold thickness; and arm muscle circumference; and differences were described according to age (all variables) and sex (body mass index). RESULTS: All anthropometric variables showed a decrease in average values with aging in men and women. The age of 70 y appeared to be the decisive moment for the main anthropometric differences observed. The values in the female group were higher than those in the male group for body mass index and triceps skinfold thickness. An important segment of the population studied had a body mass index lower than normal values. Reductions in subcutaneous fat (indicated by triceps skinfold thickness) and muscle mass (verified by arm, arm muscle, and calf circumferences) with advancing age appeared to be greater among women than among men. CONCLUSION: The present study provides information that can be used for anthropometric evaluation of elderly people in Havana and other urban areas in Cuba. The observations suggest that there is loss of muscle mass and redistribution and reduction of fat mass with age (that is more severe in women).

Association between perception of bodily discomfort and individual and work organisational factors in Brazilian slaughterhouse workers: a cross-sectional study.

OBJECTIVE: Brazil is the world's second largest poultry meat producer and leading exporter. Many poultry processing tasks are physically demanding and involve factors that increase the risk of developing a work-related musculoskeletal disorder (WMSD). However, little is known about the assessment of bodily discomfort in these workers. The aim of this study was to evaluate the association between perception of bodily discomfort and individual and work organisational factors in poultry slaughterhouse workers. DESIGN: Descriptive, cross-sectional study. SETTING: Three poultry slaughterhouses in the South of Brazil. PARTICIPANTS: This paper included 925 workers of 3 poultry slaughterhouses, 575 women and 350 men. The selection of the participants was random. MAIN OUTCOME MEASURE: Workers were asked about individual factors, work organiation, perception of bodily discomfort and cold, as well as ingestion of pain medication. Crude and adjusted ORs were estimated and 95% CIs were derived from binary logistic regression analysis for perception of bodily discomfort. RESULTS: There was a significant association (p<0.05) between perception of bodily discomfort and female gender (OR=1.77; 95% CI 1.30 to 2.41), performance of repetitive tasks (OR=1.81; 95% CI 1.12 to 2.91) and perception of cold (OR=2.05; 95% CI 1.44 to 2.91). CONCLUSIONS: The findings of this research demonstrated that the sector of occupational safety and health management in poultry slaughterhouses should monitor the symptoms of WMSD among their workers, especially female workers, workers who perform repetitive tasks, as well as those who perform tasks in cold environments because these groups are more likely to experience bodily discomfort.

Factors associated with depression symptoms in women after breast cancer.

OBJECTIVE: To analyze the factors associated with the presence of depression symptoms in women after breast cancer. METHODS: Cross-sectional study with 181 women with breast cancer, aged 57.0 years (SD = 9.5), who were undergoing treatment or after treatment in the Oncology Research Center in Florianópolis, state of Santa Catarina, Brazil. The questionnaire comprised items addressing general and health information, economic level, anthropometric measures, depression symptoms (Beck Depression Inventory), self-esteem (Rosenberg Self-Esteem Scale), and body image (Body Image After Breast Cancer Questionnaire). Descriptive and inferential statistical analysis were performed by chi-square and Fisher's exact tests to verify association, Mann-Whitney U test to compare the groups and Poisson regression to identify the prevalence ratio of the factors associated with presence of depression symptoms (p < 0.05). RESULTS: We found an association between the presence of depression symptoms and the group of younger women (aged 40-60 years), those who had another disease besides cancer, those who had mastectomy surgery, those who suffered from lymphedema, and those who presented low-medium self-esteem. Less educated women presented more depressive symptoms, as did women with worse body image on the subscales of limitations, transparency, and arm concerns. CONCLUSIONS: Age, educational attainment, diagnosis of other diseases, type of surgery, lymphedema, self-esteem, and body image were factors associated with the presence of depression symptoms in Brazilian women after breast cancer. Health professionals should be aware of these relationships and try to detect depression symptoms earlier and improve the care they provide to these women.

Empirically derived dietary patterns through latent profile analysis among Brazilian children and adolescents from Southern Brazil, 2013-2015.

The aims of this study were to identify dietary patterns (DPs) of children and adolescents participating in three cross-sectional surveys (2013-2015) and to test their associations with sociodemographic variables, physical activity (PAS), screen-based sedentary activity (SA), and weight status. One-day data were obtained from 5,364 schoolchildren (7-12 years) from public schools of Florianopolis (South of Brazil), using the validated questionnaire Web-CAAFE (Food Intake and Physical Activity of Schoolchildren). DPs were derived from the frequency of daily consumption of 32 foods/beverages by latent profile analysis. Multinomial logistic regression analysis was used to estimate the association of the DPs with sociodemographic variables, physical activity, screen activity and weight status. 'Traditional', 'Monotonous', and 'Mixed' DPs were identified. The percentages of children and adolescents within these profiles were 41.3, 36.3, and 22.4%, respectively. Children and adolescents in the highest tertiles of both PAS and daily frequency of SA had a higher probability to present a 'Mixed' DP compared to peers with less PAS and SA. Children and adolescents who reported having a school meal were significantly more likely to present the 'Traditional'DP, while boys who did not report having a school meal had a higher probability to present the 'Monotonous' DP. The DPs were not associated with the year of survey, age, family income, or weight status.

Benefits of belly dance on quality of life, fatigue, and depressive symptoms in women with breast cancer - A pilot study of a non-randomised clinical trial.

OBJECTIVE: To analyse the influence of belly dance on the quality of life, fatigue, and depressive symptoms in women with breast cancer. METHODS: Pilot study, with a design of non-randomised clinical trial study, analysing 19 women, with 8 allocated in the experimental group and 11 in the control group. The experimental group underwent 12 weeks of belly dance classes, with a frequency of twice a week and duration of 60 min for each lesson. Data collection was made through the use of questionnaires containing general information, quality of life (EORTC QLQ-BR23), fatigue (Piper Fatigue Scale) and depressive symptoms (BECK's Depression Inventory) applied on baseline and after intervention. RESULTS: The experimental group presented significant improvements after the intervention, with an increase in scores of the functional scale (p = 0.002): body image (p = 0.037) and sexual function (p = 0.027); and a decrease in scores of the symptomatic scale (p = 0.001): systemic therapy side effects (p = 0.005) and arm symptoms (p = 0.001) of quality of life, as well the decrease of fatigue (p = 0.036) and depressive symptoms (p = 0.002). No significant differences were observed in clinical and demographic information at baseline between the experimental and control groups. Also, there was no significant difference on quality of life, fatigue, and depressive symptoms between the two groups. CONCLUSION: Belly dance can be a viable form of physical activity for women with breast cancer. It was associated with benefits for quality of life, fatigue, and depressive symptoms. Even though there were significant pre-post treatment differences, there was no significance difference between the experimental and control group; and therefore, treatment could have been due to natural history.

Associations Between Caries Experience, Nutritional Status, Oral Hygiene, and Diet in a Multigenerational Cohort.

PURPOSE: To assess intergenerational associations between dental caries and nutritional status, oral hygiene habits, and diet. METHODS: A cross-sectional study was conducted with three generations of 54 families. Inclusion criteria were senior citizens with an adult son/daughter who also had a child (five to 12 years old). Dental caries was assessed using the decayed, missing, filled, primary teeth (dmft) and permanent teeth (DMFT) indexes. Nutritional status was evaluated using the body mass index (BMI), waist circumference, and percentage of body fat. Dietary habits, oral hygiene habits, and socioeconomic status were evaluated using a structured questionnaire. RESULTS: Children/adolescents with higher BMI had a lower dmft/DMFT index, and those who never or almost never consumed fruits and vegetables as snacks had a higher dmft/ DMFT index. When parents did not visit the dentist regularly, children/adolescents had more teeth affected by dental caries. When parents consumed sugar two or more times between meals, the number of affected teeth in children/adolescents increased. CONCLUSIONS: When children/ adolescents had a higher body mass index and they consumed fruits/vegetables as snacks more frequently, their caries experiences were lower. When their parents' did not visit the dentist regularly and they consumed sugar between meals more frequently, the children's caries experiences were higher.

Effects of a new walking and cycling route on leisure-time physical activity of Brazilian adults: A longitudinal quasi-experiment.

The primary aim of this study was to evaluate the effects of a new walking and cycling route on leisure-time physical activity (PA) (walking and moderate-to-vigorous PA) of adults. Furthermore, we also investigated the use, intention to use and barriers to use the new route for leisure-time PA. A longitudinal quasi-experiment was carried out. Three exposure groups were defined, based on the distance from home to the new route: 0-500m, 501-1000m and 1001-1500m. Telephone-based interviews were carried out in 2009 and 2012. Those living around the new walking and cycling route increased their leisure-time walking by 15min/week on average. Those residing up to 500m from the route increased leisure-time walking by 30min/week and walking plus moderate-to-vigorous PA by 50min/week. The proportion of people who started walking or practicing moderate-to-vigorous PA during leisure time and who reported intention to use the new route was higher among those living closer to it. Perceived distance was the most prevalent barrier to use the new route.

Development and validation of instrument for ergonomic evaluation of tablet arm chairs.

The purpose of this study was to develop and validate an evaluation instrument for tablet arm chairs based on ergonomic requirements, focused on user perceptions and using Item Response Theory (IRT). This exploratory study involved 1,633 participants (university students and professors) in four steps: a pilot study (n=26), semantic validation (n=430), content validation (n=11) and construct validation (n=1,166). Samejima's graded response model was applied to validate the instrument. The results showed that all the steps (theoretical and practical) of the instrument's development and validation processes were successful and that the group of remaining items (n=45) had a high consistency (0.95). This instrument can be used in the furniture industry by engineers and product designers and in the purchasing process of tablet arm chairs for schools, universities and auditoriums.

Associated factors and profile of injuries in professional ballroom dancers in Brazil: a cross-sectional study

Abstract Aims: Ballroom dance consists of a modality characterized by fast and dynamic movements performed in pairs, aiming at technical and artistic excellence. Objective: To analyze the prevalence, characteristics, and factors associated with injuries in professional ballroom dancers, considering possible differences between sexes. Method: 320 professional dancers of both sexes with a mean age of 31.48±8.63 years, who were in professional companies and/or dance schools from five regions of Brazil. The measurement was performed through an online self-administered questionnaire about general information and injuries. Results: A high frequency of musculoskeletal injuries (80.0%) was observed, especially osteoarticular ones (52.4%). In women, the lower limbs were the anatomical location most reported (31.1%) and the knee in male dancers (28.7%). Overweight men, with more than 11 years of dance practice, who danced in companies and also performed other physical activities, were more likely to have injuries. However, women were less likely to have injuries when they were overweight and more likely when they practiced other dance modalities besides ballroom dancing. Conclusions: Approximately 64.1% of ballroom dancers suffered an injury throughout their professional careers. For men, being overweight as well as the search for complementary activities to the physical training routine for both sexes, seem to influence the occurrence of injuries. Identification of the factors associated with injuries in ballroom dancers contributes both to preventive actions and to rehabilitation processes, favoring a healthy and safe career for professionals involved in this practice.

[Physical inactivity among non-institutionalized elderly individuals: a population-based study]. / Inatividade física em idosos não institucionalizados: estudo de base populacional.

The scope of this study is to assess the prevalence of physical inactivity among the elderly in Northeast Brazil and analyze the associated lifestyle and socio-demographic factors and health conditions. The work presented here is a descriptive and association-based study using secondary data derived from a population-based epidemiological study that included 316 elderly participants. The physical activity level of each participant was assessed using the International Physical Activity Questionnaire. The explanatory variables examined in this study were gender, age group, family set-up, ability to read and write, paid or voluntary employment, smoking, symptoms of depression, high blood pressure, fasting hyperglycemia and functional capacity. The prevalence of physical inactivity was 46.5. The results of the multivariate analysis indicated that physical inactivity was positively associated with the age group ≥ 80 years (PR = 2.37), with the lack of an occupation (PR = 4.86) and with dependence on instrumental activities of daily life (PR = 1.47) and basic activities of daily life (PR = 1.60). Physical inactivity was highly prevalent in the surveyed population, making it essential to discuss programs that encourage and enable increased physical activity to combat the risk factors of a sedentary lifestyle.

Factors associated with depression symptoms in women after breast cancer

ABSTRACT OBJECTIVE: To analyze the factors associated with the presence of depression symptoms in women after breast cancer. METHODS: Cross-sectional study with 181 women with breast cancer, aged 57.0 years (SD = 9.5), who were undergoing treatment or after treatment in the Oncology Research Center in Florianópolis, state of Santa Catarina, Brazil. The questionnaire comprised items addressing general and health information, economic level, anthropometric measures, depression symptoms (Beck Depression Inventory), self-esteem (Rosenberg Self-Esteem Scale), and body image (Body Image After Breast Cancer Questionnaire). Descriptive and inferential statistical analysis were performed by chi-square and Fisher's exact tests to verify association, Mann-Whitney U test to compare the groups and Poisson regression to identify the prevalence ratio of the factors associated with presence of depression symptoms (p < 0.05). RESULTS: We found an association between the presence of depression symptoms and the group of younger women (aged 40-60 years), those who had another disease besides cancer, those who had mastectomy surgery, those who suffered from lymphedema, and those who presented low-medium self-esteem. Less educated women presented more depressive symptoms, as did women with worse body image on the subscales of limitations, transparency, and arm concerns. CONCLUSIONS: Age, educational attainment, diagnosis of other diseases, type of surgery, lymphedema, self-esteem, and body image were factors associated with the presence of depression symptoms in Brazilian women after breast cancer. Health professionals should be aware of these relationships and try to detect depression symptoms earlier and improve the care they provide to these women.

Evaluation of mechanical properties of five cements for orthodontic band cementation.

The aim of this in vitro study was to compare the flexural, compressive and diametral tensile strengths of five cements used in orthodontics for band cementation. Twelve specimens of each cement were tested: 1 - GC Fuji Ortho Band (FJ), GC America Inc.; 2 - Meron (MR), Voco; 3 - Multi-Cure Glass Ionomer Band Cement (MC), 3M Unitek; 4 - Band-Lok (BL), Reliance Orthodontic Products; and 5 - Ketac Cem (KC), 3M ESPE. The results (mean) for diametral tensile strength were: 10.51 MPa (FJ), 9.60 MPa (MR), 20.04 MPa (MC), 42.80 MPa (BL), and 4.08 MPa (KC). The results for compressive strength were (in the same order): 64.50 MPa, 77.71 MPa, 94.21 MPa, 193.88 MPa, and 81.93 MPa. The results for flexural strength were (in the same order): 20.72 MPa, 25.84 MPa, 53.41 MPa, 137.41 MPa, and 20.50 MPa. The statistical analysis was performed by two-way ANOVA and Tukey tests with p-value £ 0.05. In terms of diametral tensile strength, BL showed the highest strength statistically, and MC, the second highest. In terms of compressive tensile strength, BL showed the highest strength statistically, and FJ did not attain the minimum recommended strength. In terms of flexural tensile strength, BL cement was superior to MC, and MR, FJ and KC were equivalent and inferior to BL and MC.