Yellow Fever Virus Reemergence and Spread in Southeast Brazil, 2016-2019.

The recent reemergence of yellow fever virus (YFV) in Brazil has raised serious concerns due to the rapid dissemination of the virus in the southeastern region. To better understand YFV genetic diversity and dynamics during the recent outbreak in southeastern Brazil, we generated 18 complete and nearly complete genomes from the peak of the epidemic curve from nonhuman primates (NHPs) and human infected cases across the Espírito Santo and Rio de Janeiro states. Genomic sequencing of 18 YFV genomes revealed the estimated timing, source, and likely routes of yellow fever virus transmission and dispersion during one of the largest outbreaks ever registered in Brazil. We showed that during the recent epidemic, YFV was reintroduced from Minas Gerais to the Espírito Santo and Rio de Janeiro states multiple times between 2016 and 2019. The analysis of data from portable sequencing could identify the corridor of spread of YFV. These findings reinforce the idea that continued genomic surveillance strategies can provide information on virus genetic diversity and transmission dynamics that might assist in understanding arbovirus epidemics.IMPORTANCE Arbovirus infections in Brazil, including yellow fever, dengue, zika, and chikungunya, result in considerable morbidity and mortality and are pressing public health concerns. However, our understanding of these outbreaks is hampered by the limited availability of genomic data. In this study, we investigated the genetic diversity and spatial distribution of YFV during the current outbreak by analyzing genomic data from areas in southeastern Brazil not covered by other previous studies. To gain insights into the routes of YFV introduction and dispersion, we tracked the virus by sequencing YFV genomes sampled from nonhuman primates and infected patients from the southeastern region. Our study provides an understanding of how YFV initiates transmission in new Brazilian regions and illustrates that genomics in the field can augment traditional approaches to infectious disease surveillance and control.

Association Between Confidence in Smiling and Esthetic Characteristics.

OBJECTIVE: This study aimed to analyze which facial, gingival and dental characteristics are associated with confidence in smiling among 75 subjects seeking treatment in a northern Brazilian public dental university. MATERIALS AND METHODS: Clinical examinations and three standardized photographs of each subject were taken by one trained examiner. In addition, a questionnaire was applied to assess confidence in smiling. The subjects were dichotomized into two groups, non-confident (n = 36) and confident (n = 39) in smiling. Chi-square/Fischer exact test were used to associate the facial, gingival and dental characteristics between groups. RESULTS: The subjects that reported to be non-confident in smiling were statistically associated with smile type (p = 0.030) and wrongly positioned teeth (p = 0.047). On the other hand, gender (p = 0.491), marital status (p = 0.217), gum pigmentation (p = 0.930), midline (p = 0.176), volume of the upper (p = 0.380), and lower (p = 0.615) lips were not associated with self-reported confidence in smiling. CONCLUSION: In patients seeking dental treatment in a public dental university, non-confidence in smiling was associated only with some oral and intraoral characteristics and not with demographic characteristics. CLINICAL SIGNIFICANCE: This study showed that only smile type and wrongly positioned teeth were statistically associated with confidence in smiling. Dentists should pay attention to those intraoral characteristics, but the clinical decision making should always include the patients' perception. (J Esthet Restor Dent 29:E56-E66, 2017).

In situ assessment of effects of the bromide- and fluoride-incorporating adhesive systems on biofilm and secondary caries.

AIM: This in situ study assessed the effects of adhesive systems containing or not fluoride and/or the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the microbiological composition of dental biofilm and enamel demineralization. MATERIALS AND METHODS: During two phases of 14 days, ten volunteers wore intraoral palatal appliances containing two slabs of human enamel according to a double-blind, crossover design. The slabs were randomly restored using a composite resin and one of the following adhesive systems: All-Bond SE(TM) (self-etch, fluoride/MDPB free adhesive, AB) and Clearfl Protect Bond (self-etch containing fluoride and MDPB adhesive, CB). The biofilm formed on the slabs was analyzed with regard to total and mutans streptococci and lactobacilli counts. Demineralization represented by integrated area of hardness × lesion depth Delta S ( ΔS) was determined on enamel by analysis of cross-sectional microhardness, at 20 and 70 µm from the restoration margin. Data were analyzed by ANOVA. RESULTS: No statistically significant difference was found either in enamel demineralization or in the microbiological composition of dental biofilm. CONCLUSION: All adhesive systems containing or not fluoride and/or MDPB tested were unable to inhibit secondary caries in the in situ model used in the present research.

Performance of molecular methods for hepatitis C virus diagnosis: usefulness among chronic cases and during the course of infection.

BACKGROUND: Molecular methods are essential to define hepatitis C virus (HCV) infection. This study was conducted to evaluate the performance of molecular qualitative and quantitative methods for HCV RNA among chronic patients and individuals during the course of HCV infection. METHODS: Single serum samples were obtained from 82 HCV infected individuals where six of them donated serial serum samples (n = 52) during the course of HCV infection. Qualitative (in-house RT-nested PCR and COBAS AMPLICOR HCV Test v2.0 and TMA) and quantitative (COBAS AMPLICOR HCV Monitor Test v2.0 and bDNA) techniques were employed. RESULTS: TMA presented the highest rate (87.8%) of HCV detection among qualitative tests and it was the most sensitive for HCV RNA detection during the early and late phases of HCV infection. HCV RNA was quantified among 56 samples and significant correlation was observed between the two assays (r 0.92; p < 0.0001). CONCLUSIONS: It is concluded that both quantitative methods can be used among chronic and acute HCV cases, but TMA was the most efficient for HCV qualitative detection among chronic cases and in the early and late phases of HCV infection.

Antiviral therapy against chronic hepatitis B in Brazil: high rates of lamivudine resistance mutations and correlation with HBV genotypes.

The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV) DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(t)ide analogue therapy for a median treatment time of 12 months. One hundred and five (81%) of these patients were treated with lamivudine (LAM), either in monotherapy or in combination with newer drugs, such as entecavir (ETV) or tenofovir (TDF). High (37.5-100%) rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV). However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%), D (30.3%) and F (9.1%) were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92%) in genotype A than in the others (p = 0.023). Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04).

Prospective follow-up of patients with acute hepatitis C virus infection in Brazil.

BACKGROUND: The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection. METHODS: From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study. Patients were prospectively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase, HCV RNA, and anti-HCV antibodies. Spontaneous viral clearance (SVC) was defined as undetectable levels of HCV RNA in serum, in the absence of treatment, for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up. Cox proportional hazards regression was used to identify host and viral predictors of SVC. RESULTS: The cumulative rate of SVC was 44.6% (95% confidence interval, 32.3%-57.5%). Compared with chronic HCV evolution, patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies (median, 109.0 vs 86.7 optical density-to-cutoff ratio [od/co]; P<.02), experienced disease symptoms more frequently (69.4% vs 100%; P<.001), and had lower viral load at first clinical presentation (median, 4.3 vs 0.0 log copies; P=.01). In multivariate analyses, low peak anti-HCV level (<93.5 od/co) was the only independent predictor for SVC; the hazard ratio compared with high anti-HCV levels (> or =93.5 od/co) was 2.62 (95% confidence interval, 1.11-6.19; P=.03). CONCLUSION: Our data suggest that low levels of anti-HCV antibodies during the acute phase of HCV infection are independently related to spontaneous viral clearance.

Hepatitis C virus-specific CD4+ T cell phenotype and function in different infection outcomes.

CD4+ T cell failure is a hallmark of chronic hepatitis C virus (HCV) infection. However, the mechanisms underlying the impairment and loss of virus-specific CD4+ T cells in persisting HCV infection remain unclear. Here we examined HCV-specific CD4+ T cells longitudinally during acute infection with different infection outcomes. We found that HCV-specific CD4+ T cells are characterized by expression of a narrower range of T cell inhibitory receptors compared with CD8+ T cells, with initially high expression levels of PD-1 and CTLA-4 that were associated with negative regulation of proliferation in all patients, irrespective of outcome. In addition, HCV-specific CD4+ T cells were phenotypically similar during early resolving and persistent infection and secreted similar levels of cytokines. However, upon viral control, CD4+ T cells quickly downregulated inhibitory receptors and differentiated into long-lived memory cells. In contrast, persisting viremia continued to drive T cell activation and PD-1 and CTLA-4 expression, and blocked T cell differentiation, until the cells quickly disappeared from the circulation. Our data support an important and physiological role for inhibitory receptor-mediated regulation of CD4+ T cells in early HCV infection, irrespective of outcome, with persistent HCV viremia leading to sustained upregulation of PD-1 and CTLA-4.

Re-introduction of dengue virus serotype 2 in the state of Rio de Janeiro after almost a decade of epidemiological silence.

The Asian/American genotype of dengue virus serotype 2 (DENV-2) has been introduced in Brazil through the state of Rio de Janeiro around 1990, and since then it has been spreading and evolving, leading to several waves of dengue epidemics throughout the country that cause a major public health problem. Of particular interest has been the epidemic of 2008, whose highest impact was evidenced in the state of Rio de Janeiro, with a higher number of severe cases and mortality rate, compared to previous outbreaks. Interestingly, no circulation of DENV-2 was witnessed in this region during the preceding 9-year period. By early 2010, phylogenetic analysis of the 2008 epidemic strain revealed that the outbreak was caused by a new viral lineage of the Asian/American genotype, which was pointed as responsible for the outbreak severity as well. The same scenario is repeating in 2019 in this state; however, only a few cases have been detected yet. To provide information that helps to the understanding of DENV-2 dynamics in the state of Rio de Janeiro, and thereafter contribute to public health control and prevention actions, we employed phylogenetic studies combined with temporal and dynamics geographical features to determine the origin of the current viral strain. To this effect, we analyzed a region of 1626 nucleotides entailing the Envelope/NS1 viral genes. Our study reveals that the current strain belongs to the same lineage that caused the 2008 outbreak, however, it is phylogenetically distant from any Brazilian strain identified so far. Indeed, it seemed to be originated in Puerto Rico around 2002 and has been introduced into the state in late 2018. Taking into account that no DENV-2 case was reported over the last decade in the state (representing a whole susceptible children generation), and the fact that a new viral strain may be causing current dengue infections, these results will be influential in strengthening dengue surveillance and disease control, mitigating the potential epidemiological consequences of virus spread.

Subtypes of temporomandibular disorders in patients diagnosed with otalgia: observational study / Subtipos de desordem temporomandibular em pacientes diagnosticados com otalgia: estudo observacional

ABSTRACT BACKGROUND AND OBJECTIVES: Temporomandibular disorder (TMD) has complex symptoms that involve the orofacial region, such as otalgia. Considering the difficult differential diagnoses for associating otological symptoms with TMD. The aim of this study was to verify the diagnosis of TMD in patients with otalgia. METHODS: This is a cross-sectional and descriptive study, where 75 patients diagnosed with otalgia were evaluated. The European Academy of Craniomandibular Disorders's (EACD) screening questionnaire was initially applied, and those who answered affirmatively to at least one question were evaluated by the Research Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), with a final sample of 50 patients. Data were tabulated and ANOVA verified whether there was a statistical difference between TMD subtypes classified by DC/TMD, considering confidence intervals with 95% significance. RESULTS: The mean age of the participants was 39.9±14.1 years, with a predominance of females (76%) (p<0.0001). Among those diagnosed with TMD, females also predominated, with a higher percentage in all evaluated subtypes, with emphasis on arthralgia (82%) and myofascial pain with limited opening (81.8%), followed by myofascial pain (74%) and disc displacement with reduction (72.7%). When observing the distribution of TMD subtypes between genders, there was a predominance of myofascial pain in males (75%) and females (68%), but no statistical significance was observed in this variable and in the others studied. CONCLUSION: Patients with otalgia had one or more TMD subtypes, and the myofascial subtype TMD was the most prevalent among study participants.

RESUMO JUSTIFICATIVA E OBJETIVOS: A disfunção temporomandibular (DTM) possui sintomas complexos que envolvem a região orofacial, como a otalgia. Considerando os difíceis diagnósticos diferenciais para associar sintomas otológicos com DTM. O objetivo deste estudo foi verificar o diagnóstico de DTM em pacientes com otalgia. MÉTODOS: Este é um estudo transversal e descritivo, com uma avaliação de 75 pacientes diagnosticados com otalgia. O questionário de triagem da Academia Europeia de Disfunções Craniomandibulares (EACD) foi aplicado inicialmente, e aqueles que responderam afirmativamente a pelo menos uma questão foram avaliados pelo Critério Diagnóstico de Pesquisa para Disfunções Temporomandibulares (DC/TMD), com amostra final de 50 pacientes. Os dados foram tabulados e por meio da ANOVA foi verificado se havia diferença estatística entre os subtipos de DTM classificados pelo DC/TMD, considerando intervalos de confiança com 95% de significância. RESULTADOS: A idade média dos participantes foi de 39,9±14,1 anos. Além disso, predominou-se o sexo feminino (76%) (p<0,0001), com maior percentual em todos os subtipos avaliados, destacando-se a artralgia (82%) e a dor miofascial com limitação de abertura (81,8%), seguida da dor miofascial (74%) e deslocamento de disco com redução (72,7%). Quando observada a distribuição dos subtipos de DTM entre os sexos, notou-se predominância de dor miofascial no sexo masculino (75%) e feminino (68%), mas não foi observada significância estatística nessa variável e nas demais estudadas. CONCLUSÃO: Os pacientes com otalgia manifestaram mais de um dos subtipos de DTM, sendo o subtipo de dor miofascial o mais prevalente entre os participantes do estudo.

Hertzian contact response of dentin with loading rate and orientation.

OBJECTIVE: To test the hypothesis that dentin Hertzian contact response varies with loading rate and tubule orientation. DESIGN: Sound teeth (n=12) were cut either parallel or perpendicular to the axial direction to expose dentin (n=6 each). The cut specimens were embedded (poly-methyl-methacrylate (PMMA) and divided into two groups: (GL) load applied parallel to dentin tubule direction and (GP) load applied perpendicular to tubule direction. A 1.5mm diameter tungsten-carbide ball was used for Hertzian contact testing with a maximum load of 150 N load and loading rates of 0.1, 1, 100, and 1000 N/s on each specimen. Indented specimens were observed microscopically and photomicrographs acquired. Hertzian contact diameter and modulus were analysed (p<0.05) by one-way ANOVA and Tukey test. RESULTS: There were significant differences (p<0.05) in Hertzian response with respect to loading rate for GL (0.1N/s versus 1000 N/s, 0.1N/s versus 100 N/s, 1N/s versus 1000 N/s, and 1N/s versus 100 N/s), and GP (0.1N/s versus 1000 N/s, 0.1N/s versus 100 N/s, and 1N/s versus 1000 N/s). Contact modulus was higher for GL compared to GP at all loading rates (p<0.05). CONCLUSION: The results suggest that dentin contact modulus is loading rate dependent. Tubule orientation of dentin did not influence contact modulus values (p>0.05).

In vivo accuracy of two electronic foramen locators based on different operation systems.

The aim of this study was to compare in vivo the accuracy of two electronic foramen locators (EFLs) based on different operation systems - Root ZX and Propex II. Ten healthy adult patients needing premolar extractions due to orthodontic reasons participated in the study, providing a sample of 17 noncarious, non-restored, vital teeth (n= 24 canals). After coronal access preparation and cervical preflaring and prior to tooth extraction, the root canal length was measured alternating the two EFLs. All measurements were performed with K-files well fitted to the canal diameter at the level that each EFL indicated the apical foramen in their display (APEX or 0.0). The last K-file were fixed in place with cyanoacrylate, the tooth was extracted, and the apical 4 mm of each root were resected to measure the distance between the file tip and the apical foramen. The mean errors based on the absolute values of discrepancies were 0.30 ± 0.29 mm (Root ZX) and 0.32 ± 0.27 mm (Propex II). Analysis by the Wilcoxon test for paired samples showed no statistically significant differences between the electronic canal measurements performed with the EFLs (p=0.587). The apical foramen was accurately located in 75% (Root ZX) and 66.7% (Propex II) of the cases, considering a ±0.5 mm error margin, with no statistically significant difference by the chi-square test. Despite having different measurement mechanisms, both EFLs were capable of locating the apical foramen with high accuracy in vivo. Under the tested clinical conditions, Root ZX and Propex II displayed similar results.

Accuracy of five electronic foramen locators with different operating systems: an ex vivo study.

OBJECTIVE: The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen. MATERIAL AND METHODS: Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%. RESULTS: Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings. CONCLUSIONS: Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.

Trans-operative reattachment of crown-root fragment: fundamentals of the technique and a case report / Colagem trans-cirúrgica de fragmento corono-radicular: fundamentos da técnica e relato de caso clínico

The functional and aesthetic restoration of crown-root fractured anterior teeth with biological width involvement represents a challenge to the clinician, because it requires a multidisciplinary approach. The trans-operative fragment reattachment technique is a feasible and advantageous alternative since it makes it possible to reestablish the original aesthetics and function of the fractured tooth in a single appointment. This work presents the fundamentals of this technique, highlighting its advantages, indications and limitations. The applications of the surgical and restorative procedures are demonstrated by way of a case report.

As fraturas dentais representam as lesões de maior incidência nos traumatismos bucais e causam um impacto negativo sobre a mastigação, fonação e estética. A restauração estético-funcional de dentes anteriores com este tipo de fratura associada a um envolvimento do espaço biológico representa um desafio ao clínico, pois exige uma abordagem multidisciplinar. Nestes casos é necessário realizar um diagnóstico cuidadoso e devem ser observados os diversos aspectos que podem direcionar a seleção da técnica restauradora mais adequada. A técnica de colagem trans-cirúrgica do fragmento dental constitui, atualmente, uma alternativa viável e bastante vantajosa, pois representa um tratamento mais conservador, seguro, rápido e, acima de tudo, eficiente em devolver a forma, o contorno, a translucidez, a textura superficial, o perfil de emergência natural do dente e a harmonia do sorriso em uma única sessão clínica. O presente trabalho se propõe a apresentar, através de um relato de caso clínico, os fundamentos da técnica de colagem de fragmento corono-radicular simultânea ao procedimento de cirurgia periodontal, destacando suas indicações, vantagens e limitações.

Effectiveness of different removal methods of artificially demineralized dentin / Efetividade de diferentes métodos de remoção de dentina desmineralizada artificialmente

Objective: This study aimed to evaluate the effectiveness of different mechanical methods for the removal of demineralized dentin. Methods: Healthy human third molars were prepared in such a way that the flat occlusal surfaces of the dentin were exposed and longitudinally sectioned in a vestibular-lingual direction. One section of each tooth was submitted to the pH-cycling model, while the other section was kept intact. The tooth sections were joined, and a single operator performed dentin removal using a steel bur, a hand instrument,or a polymer bur. The tooth’s sections were then separated, and digital images were obtained. The depth of the prepared cavities and the microhardness measurements were checked and analyzed statistically using the Kruskal-Wallis One-Way ANOVA in Ranks, the Tukey test, while desmineralized dentin were comparedusing the One-Way ANOVA, and the Holm-Sidak method (p < 0.05). Results: The steel bur produced the deepest cavities in mineralized and demineralized dentin. The polymer bur generated the shallowest cavitiesin demineralized dentin. The measurements of microhardness of the deepest surfaces of the cavities prepared in demineralized dentin indicated that the steel bur and hand instrument presented similar values, while those values produced by polymer burs proved to be lower. Conclusion: The effectiveness of the removalof demineralized dentin varied among the three methods used in this study. The polymer bur proved to bethe most conservative of the methods used. By contrast, the steel bur and hand instrument showed a similareffectiveness in the removal of dentin, according to the microhardness of the remaining dentin, even thoughthey produced different cavity depths.

In Vivo Accuracy of Two Electronic Foramen Locators Based on Different Operation Systems

The aim of this study was to compare in vivo the accuracy of two electronic foramen locators (EFLs) based on different operation systems - Root ZX and Propex II. Ten healthy adult patients needing premolar extractions due to orthodontic reasons participated in the study, providing a sample of 17 noncarious, non-restored, vital teeth (n= 24 canals). After coronal access preparation and cervical preflaring and prior to tooth extraction, the root canal length was measured alternating the two EFLs. All measurements were performed with K-files well fitted to the canal diameter at the level that each EFL indicated the apical foramen in their display (APEX or 0.0). The last K-file were fixed in place with cyanoacrylate, the tooth was extracted, and the apical 4 mm of each root were resected to measure the distance between the file tip and the apical foramen. The mean errors based on the absolute values of discrepancies were 0.30 ± 0.29 mm (Root ZX) and 0.32 ± 0.27 mm (Propex II). Analysis by the Wilcoxon test for paired samples showed no statistically significant differences between the electronic canal measurements performed with the EFLs (p=0.587). The apical foramen was accurately located in 75% (Root ZX) and 66.7% (Propex II) of the cases, considering a ±0.5 mm error margin, with no statistically significant difference by the chi-square test. Despite having different measurement mechanisms, both EFLs were capable of locating the apical foramen with high accuracy in vivo. Under the tested clinical conditions, Root ZX and Propex II displayed similar results.

O presente estudo teve como objetivo avaliar, in vivo, a precisão de dois localizadores eletrônicos foraminais (LEFs) baseados em diferentes mecanismos de funcionamento, Root ZX e Propex II, na determinação do forame apical, sendo utilizados nos mesmos dentes. Após o acesso coronário e o pré-alargamento, e anteriormente à exodontia, os comprimentos de 24 canais radiculares foram determinados eletronicamente alternando-se os dois LEFs. As odontometrias foram realizadas até que os dispositivos apontassem o FA (APEX), utilizando-se limas tipo-K ajustadas. O último instrumento utilizado foi fixado em posição, o dente extraído e os 4,0 mm apicais de cada canal desgastados de forma a possibilitar a determinação da distância entre a ponta dos instrumentos e o forame apical. Os erros médios em função dos valores absolutos das discrepâncias foram, respectivamente, 0,30 ± 0,29 mm (Root ZX) e 0,32 ± 0,27 mm (Propex II). A análise estatística realizada por meio do teste de Wilcoxon para amostras pareadas demonstrou a semelhança entre as determinações do forame apical realizadas pelos dois LEFs (p=0,587). O comprimento radicular até o forame apical foi corretamente determinado em 75% (Root ZX) e 66,7% (Propex II) dos casos, considerando margem de ± 0,5 mm, sem diferenças estatísticas quando analisados pelo teste qui-quadrado. Os LEFs avaliados e consequentemente seus mecanismos de funcionamento, foram capazes de determinar o comprimento dos canais radiculares com precisão em condições in vivo. Nas condições do presente estudo, Root ZX e Propex II apresentaram resultados semelhantes.

Reattachment of anterior teeth fragments: a conservative approach.

UNLABELLED: Coronal fractures of the anterior teeth are a common form of dental trauma that mainly affects children and adolescents. One of the options for managing coronal tooth fractures when the tooth fragment is available and there is no or minimal violation of the biological width is the reattachment of the dental fragment. Reattachment of fractured tooth fragments can provide good and long-lasting esthetics (because the tooth's original anatomic form, color, and surface texture are maintained). It also restores function, provides a positive psychological response, and is a relatively simple procedure. Patient cooperation and understanding of the limitations of the treatment is of utmost importance for good prognosis. This article reports on two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment. CLINICAL SIGNIFICANCE: Reattachment of fractured tooth fragments offers a viable restorative option for the clinician because ot restores tooth function and esthetics with the use of a very conservative and cost-effective approach.

Ensaio de microtração na avaliação da resistência adesiva: fundamentos e aplicações / The microtensile test in bond strength evaluation: fundamentals and applications

Os estudos in vitro que avaliam as propriedades mecânicas de materiais odontológicos são ferramentas de grande utilidade em Odontologia, pois auxiliam na previsibilidade do comportamento destes materiais em condições bucais e permitem a elaboração de diretrizes para a prática clínica. O ensaio de microtração constitui-se uma metodologia relativamente recente de ensaio mecânico, que consiste basicamente na divisão do espécime a ser avaliado em corpos-de-prova de dimensões menores, com área transversal de interface adesiva diminuta. Assim, obtêm-se uma área mais homogênea, propiciando uma distribuição de estresse mais uniforme, reduzindo a ocorrência de fraturas coesivas e possibilitando uma mensuração mais fidedigna da resistência adesiva real dos substratos que estão sendo testados, em relação aos ensaios convencionais de tração e cisalhamento. O presente estudo apresenta uma revisão da literatura sobre a metodologia do ensaio de microtração, enfatizando seu mecanismo, suas diversas variações e principais características, suas vantagens, desvantagens, limitações e aplicações em Odontologia.

In vitro researches which evaluate mechanical properties of dental materials are valuable tools in Dentistry since they help to make predictions for clinical practice. The microtensile bond test is a relatively recent mechanical method whose essence is the division of the resin-bonded teeth into diminutive slabs that are trimmed in such a manner that tensile force will be concentrated on the bonded interface during testing, allowing a more uniform stress distribution on the surface and reducing the occurrence of cohesive failures. This work presents a review in the literature focusing the major characteristics, advantages, applications and limitations of microtensile testing in Dentistry.

Accuracy of five electronic foramen locators with different operating systems: an ex vivo study

Objective: The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen. Material and Methods: Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%. Results: Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings. Conclusions: Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.

Antiviral therapy against chronic hepatitis B in Brazil: high rates of lamivudine resistance mutations and correlation with HBV genotypes

The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV) DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(t)ide analogue therapy for a median treatment time of 12 months. One hundred and five (81%) of these patients were treated with lamivudine (LAM), either in monotherapy or in combination with newer drugs, such as entecavir (ETV) or tenofovir (TDF). High (37.5-100%) rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV). However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%), D (30.3%) and F (9.1%) were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92%) in genotype A than in the others (p = 0.023). Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04).