In vitro comparison of one-step, two-step, and three-step polishing systems on the surface roughness and gloss of different resin composites.

OBJECTIVES: This laboratory study evaluated the effect of three polishing systems on the surface roughness and gloss of resin composites. MATERIALS AND METHODS: Thirty specimens (6 mm Ø × 8 mm) were fabricated from each of three resin composites: Z 350 XT (nanofill), Harmonize (nanohybrid), and Estelite Omega (supranonofill). All specimens were photopolymerized using a multi-peak LED curing unit (VALO-Standard mode), having a exitance irradiance of approximately 1000 mW/cm2 against a polyester strip (PS). 2 mm was then removed from the irradiated end (finished) using #320 abrasive paper (F). Specimens were then randomly polished (P) using a one-step (1S) (OneGloss), two-step (2S) (EVE Diacomp Twist Basic CA), or 3-step (3S) (Astropol P) system (n = 10). For PS, F, and P groups, surface roughness (Ra) was measured using a surface roughness tester, and surface gloss was measured with a glossmeter. For each specimen, the percent recovery to the PS value (%R) of surface roughness and surface gloss were calculated. Data were analyzed using two-way ANOVA, followed by Tukey's test. Surface roughness and gloss values were submitted to Pearson's correlation test (α = 0.05). All statistical testing was performed using a pre-set alpha of 0.05. RESULTS: The interaction term [resin composite × polishing system] was significant for both surface roughness (p = 0.001) and gloss (p = 0.0001). For all resin composites, the 2S and 3S systems provided a higher %R of surface roughness and gloss compared to those of the 1S system. There was a negative correlation between surface roughness and gloss, but only a few combinations showed strong correlations. CONCLUSIONS: The 2S and 3S polishing systems provided surfaces having greater smoothness and gloss compared to the 1S system. The ability to recover surface roughness and gloss was dependent on type of resin composite filler classification. CLINICAL SIGNIFICANCE: The 3S and 2S polishing systems were more effective in achieving PS values than was the 1S system for all tested resin composites. However, individual polishing systems performed differently depending on type of resin composite.

The effect of milling and postmilling procedures on the surface roughness of CAD/CAM materials.

PURPOSE: The aim of this study was to evaluate the surface roughness and analyze the surface topography of five different CAD/CAM ceramics and one CAD/CAM composite resin for CEREC after milling and postmilling procedures. MATERIALS AND METHODS: Blocks of the ceramics Mark II, IPS Empress CAD, IPS e.max CAD, Suprinity and Enamic, and blocks of the composite resin Lava Ultimate were milled at CEREC MCXL. Ten flat samples of each material were obtained. The surface roughness (Ra) test was performed before and after milling, crystallization, polishing, and glaze when indicated, followed by SEM and AFM analysis. Data were submitted to one-way ANOVA with repeated measures and the Tukey HSD test (α = 0.05). RESULTS: The milling step significantly increased the roughness of all the tested materials (P < .05). Lithium-based ceramics (IPS e.max CAD and Suprinity) were more suitable to roughness than the other tested materials (P < .05). CONCLUSIONS: The polishing methods were able to reduce roughness to baseline values, except for lithium-based ceramics. Glaze reduced significantly the roughness of lithium-based ceramics without a difference from the baseline. SEM and AFM images revealed that glazed surfaces are smoother than polished surfaces. CLINICAL SIGNIFICANCE: All hard-milling CAD/CAM materials, that is, fully sintered, should be only hand polished. The glaze step can be suppressed resulting in time saving. However, the glaze step in soft-milling lithium disilicate is imperative.

The addition of silica nanoparticles on the mechanical properties of dental stone.

STATEMENT OF PROBLEM: The current application of nanotechnology in dentistry is limited to nanoparticles incorporated into adhesive systems and composite resins. Dental stone is a widely used material, and the incorporation of silica nanoparticles is still unexplored. PURPOSE: The purpose of this in vitro study was to evaluate the mechanical properties of dental stone after the addition of silica nanoparticles in different concentrations. MATERIAL AND METHODS: A total of 180 specimens were prepared, 90 for each dental stone (Durone and Fuji Rock). For the control group (CG), no silica particles were added, while test group TGnI had silica nanoparticles added to 1 wt%, and test group TGnV had silica nanoparticles added to 5 wt%. The roughness, diametral tensile strength (DTS), and compressive strength were measured 24 hours after the start of spatulation. RESULTS: The mean roughness values for Durone were 0.55, 0.36, and 0.28 µm for CG, TGnI, and TGnV; for Fuji Rock, the mean roughness values were 0.47 for CG, 0.31 for TGnI, and 0.35 µm for TGnV. The mean DTS values for Durone were 6.0, 5.1, and 5.0 MPa for CG, TGnI, and TGnV, respectively, and for Fuji Rock, the mean DTS values were 6.4, 5.2, and 4.5 MPa for CG, TGnI, and TGnV, respectively. The mean compressive strength values for Durone were 35.4, 32.7, and 32.4 MPa for CG, TGnI, and TGnV, respectively, and for Fuji Rock, the mean compressive strength values were 42.9, 31.2, and 29.8 MPa for CG, TGnI, and TGnV respectively. CONCLUSIONS: Surface roughness was statistically lower for the Durone and Fuji Rock stones (P<.001) when silica nanoparticles were added. The addition of silica nanoparticles did not significantly affect the DTS and compressive strength of Durone compared with CG (P>.05) but did affect the DTS of Fuji Rock when 5 wt% was added and the compressive strength in both concentrations (P<.05).

Surface roughness and maintenance of surface sealants for resin composites after toothbrushing.

PURPOSES: (1) To evaluate in vitro the surface roughness of a resin composite covered with three surface sealants and submitted to simulated toothbrushing for different periods; (2) Verify, through scanning electron microscopy (SEM), the presence of surface sealants after simulated toothbrushing; and (3) To evaluate whether the type of dentifrice influences the maintenance of the surface sealant. The study hypothesis was that neither variable would influence the surface roughness of the composite and the maintenance of the surface sealant. METHODS: 108 specimens were prepared with the resin Amelogen Plus, and divided into six groups (n = 18) according to the type of surface sealant [Fortify (F), BisCover LV (B) and Permaseal (P)] and toothpaste [Total 12 Clean Mint (CT) and Colgate Total 12 Professional Whitening (PW)]. The samples were subjected to brushing cycles, simulating periods of 6, 12, 18, and 24 months. After each period, the surface roughness of the samples was measured. An additional group of 48 samples was prepared for SEM analysis. The results were analyzed by ANOVA with three fixed variables (sealants, time and toothpaste) and by Tukey's test (α = 0.05). RESULTS: BisCover had the lowest mean surface roughness (0.06 µm) compared with the sealants Fortify (0.09 µm) and Permaseal (0.08 µm), which were not statistically different. Fortify, at 12 months of brushing, had the highest mean roughness (0.13 µm). The mean roughness for the dentifrice CT was lower (0.07 µm) when compared with PW (0.08 µm) and was statistically different. Roughness increased up to 12 months of simulated brushing (0.04 µm, 0.08 µm and 0.11 µm), decreasing from the 18th month (0.08 µm) to the 24th month of brushing (0.07 µm). None of the sealants was observed (with SEM) to be completely removed from the resin at 24 months of brushing.

Strengthening effect of horizontally placed fiberglass posts in endodontically-treated teeth restored with direct resin composite.

PURPOSE: To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters. METHODS: 84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP). RESULTS: The data were subjected to ANOVA and Tukey's test (P < 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor.

The influence of postpouring time on the roughness, compressive strength, and diametric tensile strength of dental stone.

STATEMENT OF PROBLEM: The optimum time after pouring a dental impression before removing the dental cast is unknown with regard to the strength and roughness of the stone. Setting times and the commercial products used are important variables. PURPOSE: The purpose of this study was to evaluate the effect of postpouring time on the surface roughness, compressive strength, and diametric tensile strength of Type IV dental stone. MATERIAL AND METHODS: A total of 270 specimens were prepared from 3 commercial brands of dental stone (Durone, Fuji Rock, and Tuff Rock). Surface roughness, compressive strength, and diametric tensile strength were assessed at 1 hour, 24 hours, and 7 days after pouring. Specimens 6 mm in diameter and 3 mm in height were produced for roughness and diametric tensile strength tests. Specimens 3 mm in diameter and 6 mm in height were used to measure compressive strength. The results were analyzed with the general linear model and Tukey honestly significant difference test (α=.05). RESULTS: The surface roughness measured for the different types of dental stone tested varied from 0.3 µm (Durone, 1 hour) to 0.64 µm (Tuff Rock, 7 days). The diametric tensile strength ranged from 3.94 MPa (Tuff Rock, 1 hour) to 9.20 MPa (Durone, 7 days). The compressive strength varied from 26.67 MPa (Durone, 1 hour) to 65.14 MPa (Fuji Rock, 7 days). CONCLUSIONS: Surface roughness (P=.005), diametric tensile strength (P=.001), and compressive strength (P=.001) increased significantly with time after pouring. The commercial brand used affected roughness (P=.001), diametric tensile strength (P=.004), and compressive strength (P=.001). Tuff Rock exhibited the highest surface roughness. The highest diametric tensile strength values were recorded for Durone and Fuji Rock. Fuji Rock exhibited the highest compressive strength.

Effect of resin cements and aging on cuspal deflection and fracture resistance of teeth restored with composite resin inlays.

PURPOSE: To evaluate the influence of resin cements and aging on cuspal deflection, fracture resistance, and mode of failure of endodontically treated teeth restored with composite resin inlays. MATERIALS AND METHODS: Seventy-two maxillary premolars were divided into 6 groups: 1: sound teeth as control (C); 2: preparations without restoration (WR); 3: inlays luted with RelyX ARC (ARC); 4: inlays luted with RelyX Unicem (RLXU); 5: inlays luted with Maxcem Elite (MCE); 6: inlays luted with SeT (ST). Groups 2 to 6 received mesio-occlusal-distal preparations and endodontic treatment. Stone casts were made for groups 3 to 6. Composite resin inlays were built over each cast and luted with the resin cements. A 200-N load was applied on the occlusal aspect and the cuspal deflection was measured using a micrometer before and after 500,000 cycles of fatigue loading (200 N; 500,000 cycles). The specimens were then submitted to an axial load until failure. RESULTS: The median cuspal deflection (µm) and median fracture resistance (N) were calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (p < 0.01). Values followed by the same letter represent no statistically significant difference. Cuspal deflection before cyclic loading: C = 3 µma; ARC = 4 µmab; RLXU= 5 µmab; MCE = 21 µmb; ST = 51 µmbc; WR = 69 µmc. Cuspal deflection after cyclic loading: ARC = 6 µma; RLXU = 19 µmab; MCE = 33 µmb; ST = 62 µmb. Fracture resistance in N: C = 1902a; ARC = 980b; RLXU = 670c; MCE = 533c; ST = 601c; WR = 526c. According to the Wilcoxon test, there was no statistical difference between the cuspal deflection before and after cyclic loading only for ARC (p = 0.015). There was a predominance of recovery fractures for the restored groups. CONCLUSION: Composite resin inlays luted with RelyX ARC maintained cuspal deflection stability and showed higher fracture resistance of the teeth than did inlays luted with the other cements tested.

Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): objectives and design.

Although low- and middle-income countries still bear the burden of major infectious diseases, chronic noncommunicable diseases are becoming increasingly common due to rapid demographic, epidemiologic, and nutritional transitions. However, information is generally scant in these countries regarding chronic disease incidence, social determinants, and risk factors. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) aims to contribute relevant information with respect to the development and progression of clinical and subclinical chronic diseases, particularly cardiovascular diseases and diabetes. In this report, the authors delineate the study's objectives, principal methodological features, and timeline. At baseline, ELSA-Brasil enrolled 15,105 civil servants from 5 universities and 1 research institute. The baseline examination (2008-2010) included detailed interviews, clinical and anthropometric examinations, an oral glucose tolerance test, overnight urine collection, a 12-lead resting electrocardiogram, measurement of carotid intima-media thickness, echocardiography, measurement of pulse wave velocity, hepatic ultrasonography, retinal fundus photography, and an analysis of heart rate variability. Long-term biologic sample storage will allow investigation of biomarkers that may predict cardiovascular diseases and diabetes. Annual telephone surveillance, initiated in 2009, will continue for the duration of the study. A follow-up examination is scheduled for 2012-2013.

Disinfection of Orthodontic Elastomers and Its Effects on Tensile Strength.

OBJECTIVE: This study aimed to investigate the effect of different disinfection protocols on the mechanical properties of orthodontic elastomeric ligatures (EL), an important issue to biosafety improvement and infection control, and to avoid cross-contamination. METHODS: A total of 120 EL were randomly divided into 6 experimental groups (n = 20) according to the disinfection method employed: group 1, EL were not immersed in a disinfectant solution (control group); group 2, EL were immersed in 2% glutaraldehyde; group 3, EL were immersed in 70% alcohol solution; group 4, EL were cleaned in an ultrasound washing (UW) machine by immersion in 0.5% enzyme detergent solution; group 5, UW procedure was performed, followed by immersion in 2% glutaraldehyde; Group 6, UW procedure was performed, followed by immersion in 70% alcohol. After disinfection, EL were subjected to a tensile strength test where the maximum strength, maximum elongation, and work at failure were determined. Data were statistically evaluated using one-way ANOVA and Dunnett's t-test for multiple comparisons. RESULTS: Statistically significant different (P < .05) values were found between the disinfection methods, and 70% alcohol showed negative changes in all mechanical properties of orthodontic elastomers. By contrast, 2% glutaraldehyde did not show significant alteration in mechanical properties, whereas the UW procedure showed significant alteration in maximum strength and work at failure. CONCLUSION: Of the tested substances for disinfection, 2% glutaraldehyde was the only substance that did not cause significant changes in the mechanical properties of orthodontic elastics and is considered as an alternative for elastic disinfection before its use.

Trends in primary health care-sensitive conditions in Brazil: the role of the Family Health Program (Project ICSAP-Brazil).

BACKGROUND: This study describes trends in hospital admission rates for primary healthcare-sensitive conditions (PHCSC) in Brazil. OBJECTIVES: To evaluate the impact of increased primary healthcare availability through the implementation of the Family Health Program (FHP) on PHCSC admissions rates at the national, regional, and state-levels between 1999 and 2007. RESEARCH DESIGN: An ecologic panel data study was used and a fixed effects multivariate negative binomial model was used to estimate the association of PHCSC admission rate and FHP controlling for other relevant covariates. RESULTS: It was shown that, at the national level, PHCSC hospital admissions declined by 24%-over 2.5 times more rapidly than the decline in hospitalizations for all other (non-PHCSC) conditions. Greater reductions in the PHCSC admission rates when compared with the non-PHCSC admission rates were also observed when the data were divided by regions and states. Regression models showed that at the state level the greater the FHP coverage, the less was the PHCSC hospital admissions even when controlling for confounding variables. CONCLUSIONS: The results of this study have important implications for the healthcare model in countries that base their national health systems on primary healthcare. This is the first study to evaluate the association between FHP coverage and PHCSC admissions rates in all the Brazilian states over a long and relevant period for the consolidation of FHP in the country.

Effect of whitening dentifrices on the surface roughness of commercial composites.

PURPOSE: Our study aimed to test the null hypothesis that whitening and non-whitening dentifrices affect similarly the surface roughness of commercial microhybrid composites, independent of the brushing time. MATERIALS AND METHODS: One hundred and ninety-two disc-shaped specimens of Filtek Z250 (3 M/ESPE, St. Paul, MN, USA) and Rok (SDI, Australia) were built up and randomly assigned to 24 groups, based on the dentifrices used (two whitening dentifrices: Colgate Max White-Colgate-Palmolive, São Bernardo do Campo, São Paulo, Brazil and Close Up Extra Whitening-Unilever, Brasil Higiene Pessoal e Limpeza Ltda, Ipojuca, Pernambuco, Brazil; and one non-whitening dentifrice: Colgate Total 12 Clean Mint-Colgate-Palmolive), and on the simulated brushing times (24 hours, 6, 12 and 24 months). The specimens were submitted to the toothbrushing regimens after which the surface roughness (Ra) was measured. Data was submitted to analysis of variance and Tukey test (α=0.05). RESULTS: The composite's surface roughness was significantly affected by the composites (p=0.0007), the dentifrices (p=0.0001), and the simulated brushing time (p=0.0001). Higher roughness was observed when the whitening dentifrices were used and when the brushing time increased. Filtek Z250 was more affected than Rok, especially after 24 months of simulated brushing. CONCLUSION: Whitening dentifrices produced higher surface roughness in the composites tested. The degree of surface compromising increased with brushing time and depends on the composite's microstructure and composition.

Effect of curing time on the bond strength of a bracket-bonding system cured with a light-emitting diode or plasma arc light.

The purpose of this study was to assess the influence of two light units, a light-emitting diode (LED) and a plasma arc light (PAC), on the shear bond strength (SBS) of brackets bonded to enamel. Ninety bovine teeth were divided into six groups, according to the light-curing unit and exposure times used. In the LED (Ortholux; 3M-Unitek) group, the specimens were light cured for 5, 10, and 15 seconds. In the PAC (Apollo 95E; DenMed Technologies) group, the specimens were light cured for 3, 6, and 9 seconds. The brackets were bonded with Transbond XT (3M-Unitek), stored in distilled water at 37 °C for 24 hours and then submitted to SBS testing in a universal testing machine. The adhesive remnant index (ARI) was used to evaluate the amount of adhesive remaining on the teeth. According to analysis of variance and Tukey multiple comparisons test, the highest mean SBS was obtained with the LED at 15 seconds (16.68 MPa), which did not significantly differ from the LED 10 (14.76 MPa) or 5 (13.92 MPa) second groups (P > 0.05). The LED 10 and 5 second groups were not significantly different from the PAC 9 second group (12.66 MPa) or from the PAC 6 second group (9.96 MPa). The lowest mean SBS was obtained with the PAC 3 second group (8.29 MPa), which did not differ significantly from the PAC 6 second group. The method of light curing did not influence the ARI, with score 3 predominant. The LED at 5 seconds and the PAC at 3 seconds provided sufficient mean SBS to resist either orthodontic or masticatory forces.

Snakebite in Tocantins: ecological analysis of determinants and risk areas, 2007- 2015. / Ofidismo no Tocantins: análise ecológica de determinantes e áreas de risco, 2007-2015.

Objective To investigate the epidemiological profile of snakebite accident cases, their determinants and risk areas in the state of Tocantins. Methods This was an ecological study using data from the Notifiable Health Conditions Information System, from 2007 to 2015. Multiple linear regression and the Mann-Whitney and Kruskal-Wallis tests were used. Results A total of 7,764 snakebite accidents were reported (incidence: 62.1/100,000 inhab.; lethality: 0.5%). The variables associated with snakebite were population density (Coeff.=1.36, 95%CI 0.72;1.99), farming work (Coeff.=0.02, 95%CI 0.01;0.03), municipal human development index (Coeff.=2.99 - 95%CI 0.60;5.38), area planted with cassava (Coeff.=8.49 - 95%CI 1.66;15.32), indigenous population (Coeff.=0,02 - 95%CI 0.00; 0.04), proportion of illiterate people (Coeff.=4.70 - 95%CI 0.61;8.79) and employed people (Coeff.=3.00 - 95%CI 0.93;5,06), which together accounted for 64.48% of the variation. The high-risk areas were Amor Perfect, Cantão, Cerrado Tocantins Araguaia and Mid-North Araguaia health regions. Conclusion Municipal socioeconomic and demographic aspects were associated with snakebites.

Associated factors from loss productivity among people involved in road traffic accident: a prospective study. / Fatores associados à perda de produtividade em pessoas envolvidas em acidentes de trânsito: um estudo prospectivo.

OBJECTIVE: To study associated factors with loss productivity in people involved road traffic accidents (RTA). METHODS: The population based cohort study was conducted in Jequié, Brazil between 2013 to 2015. The instrument for interview was used in people involved in RTA and interview in four months. Individuals, occupational, health conditions, injury and support variables were used for bivariate and multivariate analysis. RESULTS: The cumulative incidence was loss productivity was 61.1% and density incidence of 7.45 cases/100 person-month. Multivariate analysis showed association for injury (IDR = 4.23; 95%CI = 2.90 - 6.17) and vehicle used with work instrument (IDR = 2.80; 95%CI = 1.62 - 4.85). CONCLUSION: Public policies are needed to ensure traffic safety in order to minimize the effects of RTA about productivity and to carry news studies to expand knowledge about loss productivity.

OBJETIVO: Estudar fatores associados à perda de produtividade em pessoas envolvidas em acidentes de trânsito (AT). MÉTODOS: Realizou-se uma coorte prospectiva de base comunitária no município de Jequié, Bahia, Brasil, entre 2013 e 2015. Foi aplicado instrumento de coleta em forma de formulário em participantes que se envolviam em AT, seguido de entrevistas a cada quatro meses. Investigou-se, por meio da análise bivariada e multivariável, a associação entre perda de produtividade e variáveis sociodemográficas e ocupacionais, condições de saúde e gravidade das lesões. RESULTADOS: Observaram-se incidência cumulativa de perda de produtividade de 61,1% e densidade de incidência geral de 7,45 casos/100 pessoas/mês. A análise multivariável demonstrou associação com perda de produtividade para quem utilizava o veículo como instrumento de trabalho (razão de densidade de incidência - RDI = 4,23; intervalo de confiança de 95% (IC95%) = 2,90 - 6,17) e aqueles que apresentaram lesão corporal (RDI = 2,80; IC95% = 1,62 - 4,85). CONCLUSÃO: São necessárias políticas públicas que assegurem a segurança no trânsito a fim de minimizar os efeitos dos AT sobre a produtividade, além da realização de novos estudos na área para ampliar o conhecimento sobre o tema.

Productivity costs among people involved in traffic accidents. / Custos de produtividade entre pessoas envolvidas em acidentes de trânsito.

This paper aimed to characterize the productivity costs of people involved in traffic accidents (TA) in a medium-sized municipality. A longitudinal household-based study was conducted from 2013 to 2015. During this period, individuals with TA were interviewed, and followed-up and costs of productivity were calculated. The measured and estimated values were considered for the calculation of the gross and per capita values and facilitated the establishment of costs of lost productivity (days off work) and costs of return to productivity (health professionals, medication, transportation, auxiliary devices and vehicle repair). It was shown that the costs of loss were more significant against the costs of return. Among the items that underpin the return to productivity, higher costs were observed in men, young adults, drivers, users of two-wheeled vehicles, people with public employment relationships, intermediate age groups and fracture-type injuries. It is necessary to evaluate and target the stages of recovery of those involved to minimize the social burden generated by these events.

Este artigo objetivou caracterizar os custos de produtividade de pessoas envolvidas em acidente de trânsito (AT) em um município de médio porte. Um estudo longitudinal de base domiciliar foi realizado entre 2013 e 2015. Neste período, foram entrevistados e acompanhados indivíduos com AT e calculados os custos de produtividade. Os valores mensurados e estimados foram considerados para cálculo dos valores brutos e per capita e ajudaram a constituir os custos de perda de produtividade (dias sem trabalhar) e custos de retorno à produtividade (profissionais de saúde, medicamentos, transporte, dispositivos auxiliares e reparo de veículos). Demonstrou-se que os custos de perda foram maiores em relação aos custos de retorno. Entre os itens que compõem os de retorno à produtividade, observaram-se maiores custos em homens, adultos jovens, condutores, usuários de veículos de duas rodas, pessoas com vínculo público, em faixas etárias intermediárias e lesões do tipo fratura. São necessárias a avaliação e o direcionamento nos estágios de recuperação dos envolvidos a fim de minimizar o ônus social gerado por estes eventos.

Factors associated with traffic accidents among drivers: findings from a population-based study. / Fatores associados a acidentes de trânsito entre condutores de veículos: achados de um estudo de base populacional.

This study aimed to identify associated factors with drivers' involvement in traffic accidents (TA). Thus, in 2013, a household survey was conducted with 1,406 drivers in Jequié, Bahia, Brazil. A hierarchical conceptual model was established and consisted of four blocks of exposure factors, considering the proximal-distal relationships between them and the outcome. Multilevel logistic regression was applied to estimate the Odds Ratio (OR) and 95% Confidence Intervals (95%CI). Higher TA probability was observed among drivers aged 15-29 years (OR=3.15; 95%CI 1.24-8.02), with black or brown skin color (OR=1.56; 95%CI 1.03-2.35), motorcyclists (OR=1.73; 95%CI 1.15-2.60), with a history of traffic tickets (OR=1.75; 95%CI 1.04-2.94), who reported drinking and driving (OR=1.68; 95%CI 1.12-2.53) and used cell phone while driving (OR=1.63; 95%CI 1.09-2.43). Proximal factors changed the exposure association measures concerning higher levels of determination of the hierarchical model, mainly regarding the gender variable. The results emphasize the behavioral factors and reaffirm the TAs' preventable potential due to the occurrence of avoidable conditions associated with the outcome.

O estudo teve por objetivo identificar fatores associados ao envolvimento em acidentes de trânsito (AT) entre condutores de veículos. Para isso, realizou-se inquérito domiciliar na cidade de Jequié, Bahia, em 2013, com 1.406 condutores. Elaborou-se um modelo conceitual hierarquizado composto por quatro blocos de fatores de exposição, considerando as relações proximais-distais entre estes e o desfecho. Foi empregado modelo de regressão logística multinível para as estimativas de Razão de Chances (RC) e Intervalos de Confiança a 95% (IC95%). Observou-se maior chance de AT entre condutores de 15 a 29 anos (RC=3,15; IC95% 1,24-8,02); de cor da pele preta ou parda (RC=1,56; IC95% 1,03-2,35); motociclistas (RC=1,73; IC95% 1,15-2,60); com antecedentes de multa no trânsito (RC=1,75; IC95% 1,04-2,94); que referiram beber e dirigir (RC=1,68; IC95% 1,12-2,53) e usar telefone celular durante a condução (RC=1,63; IC95% 1,09-2,43). Os fatores proximais modificaram as medidas de associação das exposições dos níveis superiores do modelo hierarquizado, principalmente da variável sexo. Os resultados enfatizam os fatores comportamentais e ratificam o potencial de prevenção dos AT, em virtude da ocorrência de condições evitáveis associadas ao desfecho.

Fracture strength of endodontically treated molars transfixed horizontally by a fiber glass post.

PURPOSE: To assess the effect of a horizontally transfixed fiber glass post placed between buccal and palatal surfaces, on the fracture strength of endodontically treated molar teeth with MOD cavities, either restored with resin-based composite, or not. METHODS: 75 sound maxillary human third molars were extracted, embedded in acrylic resin blocks and randomly assigned to five groups (n=15). Group A (sound teeth), (control) and Groups B, C, D and E, which were subjected to the following procedures after endodontic treatment: GB--(MOD+Endo), GC--(MOD+Endo+Post), GD--MOD and composite restoration (MOD+Endo+CR), GE--(MOD+Endo+Post+CR). The specimens were stored in distilled water at 37 degrees C for 24 hours. Later, a compressive force was applied by means of a universal testing machine at 1 mm/minute speed, parallel to the long axis of the teeth until fracture occurred. RESULTS: The means of the results (N) followed by the same letter represent no statistical difference by ANOVA and Tukey (P<0.05): GA = 4289.8 (+/- 1128.9)a, GB = 549.6 (+/- 120.7)b, GC = 1474.8 (+/- 338.1)c, GD = 1224.7 (+/- 236.0)c, GE = 2645.4 (+/- 675.1)d. In the analysis of qualitative variables, there was a tendency to cusp fracture in all groups except for Group C. The fiber glass post transfixed horizontally in a MOD cavity significantly increased the fracture resistance of the teeth restored with resin composite.

Stress distribution of an internal connection implant prostheses set: a 3D finite element analysis.

OBJECTIVE: This study evaluated the stress distribution by loads, under a internal connection implant system with two sort of abutment screws and prosthetic crown models at ten observation points. MATERIALS AND METHOD: The analysis were made in two models with internal butt joint, and with gold and titanium screw, respectively. The load was 382N with 90 masculine to the occlusal surface and 15 masculine to the implant axis at 4 and 6 mm from the implant center. RESULTS: In both models, a large amount of stress was located around the implant neck and little stress was concentrated along the abutment screw. CONCLUSION: The simulations made suggest that the internal connection protects the abutment screw from the accumulated stresses; however, it exposes the implant walls to these stresses.

Marginal fit analysis of premachined and castable UCLA abutments.

This study evaluated the fit between implants and premachined and castable UCLA abutments. All plastic specimens were cast using the conventional technique in accordance with the manufacturer's instructions. Five specimens of each experimental group were measured for vertical and horizontal gaps by scanning electronic microscopy (Phillips XL 30 model, Holland). Gold UCLA (vertical gap: 2.15 microm, horizontal gap: 11.30 microm) and castable rotational UCLA (vertical gap: 14.91 microm, horizontal gap: 59.41 microm) groups showed the lowest and highest mean values, respectively (Neodent, Curitiba, Parana, Brazil). In general, the castable UCLA abutments showed poorer marginal fit than the premachined abutments.

Traffic accidents among drivers: incidence and differences between motorcyclists and car drivers in population-based study. / Acidentes de trânsito com condutores de veículos: incidência e diferenciais entre motociclistas e motoristas em estudo de base populacional.

OBJECTIVES: To estimate the incidence of traffic accidents among land vehicle drivers and to verify differences between motorcyclist and car driver accident victims. METHODS: A household survey was conducted in Jequié city, Bahia, Brazil, in 2013, with 1,406 drivers who were selected by cluster sampling strategy. Estimates of the cumulative incidence of traffic accidents were weighted by the sample design and, to compare groups of drivers, incidence rates (IR) and 95% confidence intervals were calculated with Poisson Regression. The Chi-Square test were used with Rao-Scott correction (p ≤ 0.05) to evaluate differentials of the event between motorcyclists and car driver victims. RESULTS: Involvement in traffic accidents in the last 12 months before the interview was reported by 10.6% of the drivers. The cumulative incidence was 4.3% for accidents that caused injuries. Motorcyclists had double the risk of being involved in accidents (IR = 2.03; 95%CI 1.40 - 2.94) and higher proportions of injuries (p < 0.001), interruption in daily life activities (p = 0.003) and use of emergency services (p = 0.008). Factors related to time and place of accident were not different between groups. CONCLUSION: Higher incidence of traffic accidents and higher proportions of injuries and others repercussions of these events were seen in motorcyclists. These findings reaffirm the vulnerability of this group and explains the different impact that a preventable cause of morbidity and mortality has on each driver group.

OBJETIVOS: Estimar incidências de acidentes de trânsito entre condutores de veículos a motor e verificar diferenciais do evento entre as vítimas motociclistas e motoristas de automóvel. MÉTODOS: Foi conduzido um inquérito domiciliar no município de Jequié, Bahia, em 2013, com 1.406 condutores selecionados por amostragem por conglomerado. As estimativas de incidência cumulativa de acidentes de trânsito foram ponderadas pelo desenho amostral e, para comparação entre categorias de condutores, foram estimadas razões de incidência (RI) e intervalos de confiança de 95% (IC95%) com regressão de Poisson. Diferenciais do evento entre vítimas motociclistas e motoristas foram avaliados com teste do χ2 de Rao-Scott (p ≤ 0,05). RESULTADOS: O envolvimento em acidentes de trânsito nos 12 meses anteriores à entrevista foi referido por 10,6% dos condutores. Para acidentes que causaram lesão física, a incidência foi de 4,3%. Motociclistas apresentaram o dobro do risco de envolvimento em acidentes (RI = 2,03; IC95% 1,40 - 2,94) e maiores proporções de lesões (p < 0,001), de interrupção de atividades habituais de vida (p = 0,003) e de atendimento em serviços de emergência (p = 0,008). Fatores relacionados ao tempo e local de ocorrência não se diferenciaram entre grupos. CONCLUSÃO: Maior incidência de acidentes e proporções mais elevadas de lesões e de outras repercussões desses eventos recaíram sobre motociclistas. Tais achados reafirmam a condição de vulnerabilidade desse grupo e explicitam diferentes impactos que uma causa prevenível de morbimortalidade apresenta em cada grupo de condutores.