RESUMO

To evaluate the internal morphology of 100 distal roots of mandibular first molars using micro-CT. Teeth were scanned to characterise: Vertucci type, root length, canal shape, presence and location of accessory canals, and the number of foramina at 4 mm from the apex, presence of root isthmus and the length from the primary canal to the apical foramen. Vertucci type I was found in 57% of cases, followed by V (27%). The most common cross-section 1 mm from the apex was oval (49%) and circular (38%). The average root length was 16.06 mm (16.61-19.02 mm). The mean foramen size was 0.32 and 0.53 mm for the minor and major diameters, respectively. The volume, surface area and SMI were 7.84 mm3 , 68.87 mm2 and 1.52 mm, respectively. Root isthmi were found in 47% of the samples, and the length mean from the primary canal to the apical foramen was 2,03 mm. The internal morphology of the distal roots of mandibular first molars may be complex and shows variations.

Assuntos

RESUMO

ABSTRACT Objective: To evaluate and compare antibiotic prescriptions for endodontic infections of last-year undergraduate Dentistry students and dental surgeons from Brazil. Material and Methods: A questionnaire comprised of 15 questions was applied, including a series of hypothetical clinical cases through multiple choice questions. The survey respondents had the option to respond in favor or against the prescription of antimicrobials in each case. Afterwards, the commented answer keys of all topics contained in the survey form were released for educational purpose. Results: A total of 42 undergraduates and 115 dental surgeons answered the survey. Regarding the questions about antimicrobial prescriptions, 91.3% of the professional dentists and 69.8% of the dentistry students indicated that they prescribe antibiotics for a limited number of patients. However, when they responded about drug recommendations, most professionals (76.5%) and students (76.7%) chose to recommend antimicrobials without any clinical recommendation. Conclusion: In the groups herein evaluated, many antibiotic prescriptions could have been avoided. The rational use of these drugs is still a conduct that needs further disclosure and commitment among prescribers.

Assuntos

RESUMO

O escurecimento dental pode ser interpretado como um ponto de tensão visual e a busca pelo clareamento dos elementos dentários são baseados na percepção individual e imersa sobre interferências culturais que o indivíduo sofre. A preocupação com a estética do sorriso é histórica, tendo diversos mecanismos que foram usados para branquear os dentes e limpá-los (CONSOLARO, 2013). Atualmente, têm-se um forte apelo pelas mídias levando os indivíduos a buscarem meios para alcançarem o referido padrão estético (RAMOS; MONNERAT; PEREZ, 2014). A classificação dos produtos branqueadores como cosméticos traz prejuízo quanto ao uso irracional e sem supervisão, pois decorre de uma ideia diferente que se tem popularmente que apenas medicamentos podem trazer prejuízos à saúde, assim, seria melhor classificá-los como medicamentos, até porque são capazes de acarretarem mudanças fisiológicas (CONSOLARO, 2013). Diante do exposto, a FDA (Food and Drug Administration) começou a classificá-los como medicamentos ou drogas em 1991 (CONSOLARO A; FRANCISCHONE; CONSOLARO R, 2011). Os agentes branqueadores são à base de peróxido de hidrogênio (H2O2) e são encontrados em dentifrícios, enxaguantes bucais, clareamento dental de consultório e caseiro, e a própria água oxigenada usada para bochecho. Outros meios podem ser vistos na busca pelo clareamento dos dentes: o uso do bicarbonato de sódio, dentifrícios mais abrasivos e produtos com carvão ativado

Assuntos

RESUMO

OBJECTIVE: Airborne particles are one of the most important factors in the spread of infectious pathogens and must be monitored in healthcare facilities. Viable particles are living microorganisms, whereas non-viable particles do not contain microorganisms but act as transport for viable particles. The effectiveness of ozone in reducing these particles in a non-controlled room and a controlled cleanroom using high-efficiency particles air (HEPA) filter was analyzed in this study. MATERIALS AND METHODS: Viable particles and non-viable particles sized 0.5 and 5 µm were quantified before and after ozonation in two different health environments: non-controlled (group 1) and controlled area, which was associated with a HEPA filtering system (group 2). Active air sampling using a MAS 100 was used to count the number of viable particles, while the number of non-viable particles/m3 was obtained following the manufacturer's recommendations of the Lasair III 310C system. RESULTS: Our results of the viable particles counting were not quantifiable and analyzed using statistical tests. Both groups showed a slight tendency to reduce the number of viable particles after ozonation of the environmental air. A statistically significant reduction of non-viable 5 µm particles after ozonation was observed in both groups (G1: p = 0,009; G2: p = 0,002). Reduction in the non-viable 0.5 µm particles after ozonation was observed only in group 2, associated with the HEPA filter. In group 1, after ozonation, a significant increase in 0.5 µm particles was observed, probably due to the breaking of 5 µm particles by ozone gas. Our results suggest that ozone gas can break 5 µm particles and, when associated with a HEPA filter, increases its effectiveness in removing 0.5 µm particles. CONCLUSION: Considering that 5 µm particles are important in the air transport of microorganisms, their reduction in the environment can be a relevant parameter in controlling the dissemination of infections.

RESUMO

OBJECTIVE: The aim of present study was to assess the cytotoxicity and antimicrobial efficacy of 2% peracetic acid (PAA) compared with 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX). MATERIAL AND METHODS: For the cytotoxicity test, 100 µl of the tested solutions were added in 12 wells with ECV 304 endothelial cells in each group: NaOCl, CHX, and PAA, in addition to the control group. Each solution was evaluated after 24 hours of contact in four dilutions: 0.2, 0.1, 0.05 and 0.025 through mitochondrial function using MTT colorimetric assay. In the antimicrobial evaluation, 40 dentin blocks 5 mm in length and 0.2 g in weight were incubated with 400 µl of Enterococcus faecalis suspension for 21 days at 37°C. The contaminated samples were divided into three experimental groups within 5 minutes of contact: NaOCl group, CHX group, PAA group, as well as the positive control group. The specimens received treatment and were transferred to a tube with saline for serial dilution of the solution and seeding for isolation and colony forming unit (CFU) count. STATISTICAL ANALYSIS: The results obtained were expressed as mean (A570 nm) ± standard deviation (SD) and in a multiple linear regression model and multiple comparisons conducted. RESULTS: The antimicrobial evaluation revealed that the NaOCl and CHX groups showed a statistically significant difference compared with the control group (p < 0.001), while the PAA reduced only the CFU growth. It can be concluded that, among the agents tested, PAA expressed greater cell viability, followed by CHX and NaOCl. However, it did not show greater antimicrobial activity in vitro in the mature biofilm of Enterococcus faecalis.

RESUMO

OBJECTIVES: To determine whether phenotypic and genotypic differences amongst isolates ofEnterococcus faecalis relate to geographical and clinical origin. METHODS: E. faecalis from primary endodontic infections in Brazilian patients (n = 20), oral infections in UK patients (n = 10), and non-oral infections in Japanese patients (n = 9) were studied. In addition, 20 environmental vancomycin resistant Enterococcus faecalis (VRE) isolates from a UK hospital were analysed. For all isolates, polymerase chain reaction (PCR) was used to detect genes associated with antibiotic resistance and virulence, whilst randomly amplified polymorphic DNA-PCR (RAPD-PCR) was used to produce molecular profiles. RESULTS: Gelatinase gene (gelE) was prevalent amongst isolates (77-100%) and for oral isolates, genes of aggregation substances (agg), immune evasion protein (esp), cytolysin (cylB), tetracycline resistance (tetM; tetL) and erythromycin resistance (ermB) were detected to varying extent. Japanese non-oral isolates had a similar genetic profile to oral isolates, but with higher prevalence of ermB and cylB. All VRE isolates were positive for gelE, esp, agg, vanA, ermB and tetM, 95% were positive for cylB and 17% positive for tetL. All isolates were negative for ermA, asa373 vanB, vanC1 and vanC2/3. RAPD-PCR revealed clustering of VRE isolates. CONCLUSIONS: RAPD-PCR analysis revealed extensive genetic variability among the tested isolates. Oral isolates carried antibiotic resistance genes for tetracycline and whilst they possessed genes that could contribute to pathogenicity, these were detected at lower incidence compared with non-oral and VRE isolates. RAPD-PCR proved to be a useful approach to elucidate relatedness of disparate isolates.

Assuntos

RESUMO

AIM: The aim of this study was the assessment of the anatomical thickness of danger zone in the cervical third of mesial canals of mandibular molars. MATERIALS AND METHODS: Fifty mandibular molars were selected and scanned with cone-beam computed tomography. Data were compared using a length tool provided by scanner software. The measured areas were the mesial and distal walls of the cervical third of the mesial roots, which correspond to the safety and danger zones, respectively. In addition, dentin thickness at the furcation was evaluated. RESULTS: Dentin thicknesses of the safety zone were higher than in the danger zone in all teeth examined. The thinnest dentin of the safety zone was found at a point located 4 mm below the canal orifice, with a mean value of 1.03 mm; conversely, in the danger zone, the thinnest point was located 3 mm below the orifice, with a mean value of 0.81 mm. As for the distance from the pulp chamber floor to the furcation, the average value was 2.23 mm. CONCLUSION: These results show that mean thicknesses at the danger zone of mandibular molar mesial roots were <1.0 mm. These data reinforce the importance of understanding anatomy and the need for conservative preparations when assessing and instrumenting these root canals.

RESUMO

Introdução: o tratamento de dentes jovens traumatizados requer atenção especial, devido à possível presença de ápice incompleto e paredes dentinárias delgadas, o que pode dificultar ou comprometer o tratamento endodôntico convencional. Faz-se necessária a realização de um procedimento para induzir a formação de uma barreira mineralizada, com o auxílio de materiais biocompatíveis, como o hidróxido de cálcio e o agregado trióxido mineral (MTA). Objetivo: relatar um caso clínico em que foi realizada apicificação, com tampão de MTA, em um incisivo lateral superior traumatizado. Conclusão: o uso de MTA como material obturador de dentes com ápice incompleto mostrou- se eficiente, pois permitiu resolução do caso com sucesso e a manutenção do dente na arcada, exercendo suas funções primárias quanto à estética e à mastigação.

Assuntos

RESUMO

Introduction: Light-cured resin cements are the first choice for the cementation of laminate veneers. Ideally, they should be biocompatible and offer minimum risks to patients. Objective: The aim of this study was to evaluate, in vitro, the cytotoxicity of three resin cements: Variolink II, Ivoclar Vivadent (C1), Allcem Veneer, FGM (C2), and Rely X Veneer, 3M ESPE (C3). Material and method: Twenty four samples of each of the cements were fabricated in a standardized metal mold, light activated, and transferred to a 96-well cell plate with culture of fibroblasts. After 24, 48, and 72h of incubation, cytotoxicity was assessed and cell viability was calculated by the methyl-thiazol-tetrazolium (MTT) colorimetric assay. Absorbance was measured at 570 nm using a microplate spectrophotometer. Result: The following results were found: Variolink II presented viability of 72.24% (SD 6.80) after 24h, 83.92% (SD 5.26) after 48h, and 92.77% (SD 5.59) after 72h; Allcem Veneer exhibited viability of 70.46% (SD 12.91) after 24h, 85.03% (SD 21.4) after 48h, and 70.46% (SD 12.91) after 72h; Rely X Veneer showed viability of 5.06% (SD 0.88) after 24h, 5.84% (SD 1.18) after 48h, and 6.99% (SD 1.34) after 72h. Conclusion: Under these testing conditions, Rely X Veneer presented significantly higher cytotoxicity compared with those of the other light-cured resin cements assessed.

Introdução: Cimentos resinosos fotopolimerizáveis são materiais de eleição para a cimentação de facetas laminadas. Devem ser biocompatíveis oferencendo riscos mínimos ao uso clínico em pacientes. Objetivo: O objetivo desse trabalho foi avaliar in vitro a citotoxicidade de três cimentos resinosos: Variolink II (Ivoclar Vivadent), Allcem Veneer, (FGM) e Rely X Veneer (3M ESPE). Material e método: Vinte e quatro corpos de prova de cada cimento foram confeccionados em matrizes metálicas padronizadas e inseridos em placa de cultura de células de noventa e seis poços contendo fibroblastos da linhagem 3T3. As células foram cultivadas em meio de cultivo celular RPMI 1640 com 5% de soro fetal bovino, com 0,1% de penicilina/estreptomicina em estufa a 37◦C, em atmosfera úmida com 5% de CO2. O grau de citotoxicidade de cada cimento foi avaliado após os tempos de contato de 24h, 48h e 72h através do método MTT (3-(4,5-dimetiltiazol-2yl)-2,5- difenil brometo de tetrazolina), que avalia a viabilidade celular pela função mitocondrial. Após os tempos estabelecidos, as amostras foram removidas, tratadas e levadas ao espectofotômetro de microplaca para leitura da absorbância em 570nm. Resultado: O cimento Variolink apresentou em 24h viabilidade de 72,24% (±6,80), em 48h de 83,92% (± 5,26) e de 92,77% (±5,59) em 72h. Allcem Veneer apresentou viabilidade de 70,46% (± 12,91) em 24h; 85,03% (± 21,4) em 48h e 70,46% (± 12,91) em 72h. O RelyX Veneer demonstrou viabilidade de 5,06% (± 0,88) em 24h; 5,84% (± 1,18) em 48h e 6,99% (± 1,34) em 72h. Conclusão: Estes resultados demonstraram que o cimento Rely-X se apresentou significativamente mais citotóxico nas condições testadas.

Assuntos

RESUMO

Introduction: Cervical preflaring is an important step of the canal system instrumentation, but can lead to excessive enlargement or root perforation. Objective: Evaluate the remaining dentin thickness in the mandibular molars of mesial roots using cone beam computed tomography: Gates-Glidden (crown-down); Gates-Glidden (step-back); LA Axxess and Easy Pro-Design. Material and method: Were selected 40 lower molars mesial roots, which were scanned in a cone beam CT scanner before and after preparation. Were obtained five sections of the CT images with an interval of 1 mm from the furcation, and measured the thickness variation between the root canal to the root external portion in analysis software. Result: The evaluation of the different levels showed no significance within the same group for the Gates-Glidden group. On the other hand, were observed difference for LA Axxess (p=0.002) and Easy Pro-Design (p=0.005). In the intergroup analysis, were observed difference in all levels, especially for Gates-Glidden in the ascendant order (ANOVA and Tukey). Conclusion: Within the limitations of these study, is possible to conclude that the protocol with greater wear in the cervical risk area was the Gates-Glidden in step-back sequence, as the other groups were equivalent (p>0.05).

Introdução: O preparo cervical é uma etapa importante da instrumentação do sistema de canais, mas pode levar ao alargamento excessivo ou rasgo da raiz. Objetivo: Avaliar, em tomografia computadorizada cone beam, da espessura remanescente de dentina cervical da raiz mesial de molares inferiores, após o preparo com diferentes técnicas: Gates-Glidden (ordem crescente); Gates-Glidden (ordem decrescente); LA Axxess e Easy Pro-Design. Material e método: Foram selecionadas 40 raízes mesiais de molares inferiores, que foram escaneadas em tomógrafo cone beam antes e após o preparo. Das imagens tomográficas foram obtidos cinco cortes com intervalo de 1 mm a partir da furca e, então, mensurada a variação da espessura entre o canal radicular até a porção externa da raiz em software de análise. Resultado: Avaliação dos diferentes níveis demonstraram ausência de significância dentro do mesmo grupo para o grupo das Gates-Glidden. Por outro lado, foi notada diferença para LA Axxess (p=0,002) e para Easy Pro-Design (p=0,005). Na avaliação entre os grupos, foi observada diferença em todos os níveis, sobretudo, para Gates-Glidden na ordem crescente (ANOVA e Tukey). Conclusão: Considerando as limitações desse estudo, concluiu-se que o protocolo que apresentou maior desgaste da área de perigo cervical foi o da Gates-Glidden em ordem crescente, sendo que os demais grupos foram equivalentes (p>0,05).

Assuntos