Influence of etchant type on the shear bond strength of orthodontic brackets to enamel.

The aim of this study was to evaluate the influence of the type of etchant on the shear bond strength (SBS) of metallic brackets to enamel and the Adhesive Remnant Index (ARI) after debonding. A total of 30 mandibular and maxillary premolars were randomly distributed into groups (n = 10) treated with 1 of 3 enamel surface-conditioning agents: 35% phosphoric acid (PA), 35% glycolic acid (GA), or 35% ferulic acid (FA). The designated acid was applied to the buccal enamel surface of the tooth for 20 seconds, and the tooth was then rinsed with distilled water for 20 seconds and air dried for 5 seconds. A metal bracket was bonded to the prepared surface with light-cured orthodontic resin. After 24 hours, the bracket-tooth interface was submitted to SBS testing in a universal testing machine at a speed of 0.5 mm/min. After debonding, the enamel surface was observed under a stereomicroscope (×20 magnification) to determine the ARI. The generalized linear models showed that the PA and GA groups presented significantly higher SBSs than the FA group (P = 0.0003). The ARI was significantly higher in specimens treated with PA than with the other acids (P < 0.05; Kruskal-Wallis and Dunn tests), with a larger quantity of adhesive remaining adhered to the tooth. Both PA and GA are effective for bonding brackets, but GA resulted in a lower percentage of adhesive remnant adhered to the enamel.

Oral epithelial dysplasia grading: Comparing the binary system to the traditional 3-tier system, an actuarial study with malignant transformation as outcome.

BACKGROUND: Establishing the risk of malignant transformation (MT) in oral leukoplakia is usually based on grading oral epithelial dysplasia (OED) on biopsy tissue, for which two systems are proposed: a 3-tier and a binary system. Only very few actuarial studies have tested the accuracy of such methods in predicting MT, especially for the binary system. This study aimed to assess the accuracy of the two grading systems in predicting MT in a cohort of oral leukoplakia (OL) from Brazil, with follow-up data. METHODS: The sample comprised 878 individuals diagnosed with OL from 2005 to 2018. Follow-up data were obtained both locally and from the regional cancer registry. All lesions were graded using both the 3-tier and the binary systems. Kaplan-Meier curves (Log-rank Mantel-Cox) were used to assess risk and kappa to assess interobserver agreement. RESULTS: Thirty-five individuals underwent MT (4%). Both systems demonstrated prognostic value, though the 3-tier system proved superior, with OR 9.23 (3.42-23.69), PPV 0.152, NPV 0.98, compared to binary OR 3.49 (1.79-6.79), PPV 0.079, NPV 0.976. Interobserver agreement was also superior in the 3-tier system (0.47, p < 0.05) compared to the binary system (0.139, p = 0.39). Combining the two systems enhanced prognostic values (OR 14.28, PPV 0.217, NPV 0.981). CONCLUSION: The 3-tier system presented superior prognostic value to the binary system. Combining both systems to double-grade intermediate lesions might enhance risk assessment.

Soluble epoxide hydrolase inhibitor, TPPU, increases regulatory T cells pathway in an arthritis model.

Epoxyeicosatrienoic acids (EET) and related epoxy fatty acids (EpFA) are endogenous anti-inflammatory compounds, which are converted by the soluble epoxide hydrolase (sEH) to dihydroxylethersatrienoic acids (DHETs) with lessened biological effects. Inhibition of sEH is used as a strategy to increase EET levels leading to lower inflammation. Rheumatoid arthritis is a chronic autoimmune disease that leads to destruction of joint tissues. This pathogenesis involves a complex interplay between the immune system, and environmental factors. Here, we investigate the effects of inhibiting sEH with 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) on a collagen-induced arthritis model. The treatment with TPPU ameliorates hyperalgesia, edema, and decreases the expression of important pro-inflammatory cytokines of Th1 and Th17 profiles, while increasing Treg cells. Considering the challenges to control RA, this study provides robust data supporting that inhibition of the sEH is a promising target to treat arthritis.

Epithelial membrane antigen and DOG1 expression in minor salivary gland tumours.

Epithelial membrane antigen (EMA) and DOG1 are used as marker of epithelial cells, particularly the luminal cells, of salivary gland tumours. The aim of this study was to compare the EMA and DOG1 expression in tumours of minor salivary glands. Cases of pleomorphic adenoma (PA), basal cell adenoma (BCA), canalicular adenoma (CA), adenoid cystic carcinoma (ACC), polymorphous adenocarcinoma (PAC), mucoepidermoid carcinoma (MEC) and epithelial-myoepithelial carcinoma (EMC) were submitted to immunohistochemistry for EMA and DOG1. In PA and BCA, EMA and DOG1 were observed in luminal cells, while in CA the tumour cells were negative for both proteins. The EMA and DOG1 pattern expression detected in EMC was similar to that one observed in benign tumours. In ACC, both myoepithelial e epithelial expressed EMA and DOG-1. PAC tumour cells were only positive for DOG1, whereas MEC were only positive for EMA. In conclusion, EMA and DOG1 expression in benign salivary gland tumours was similar to normal salivary gland tissue and can be used as good marker of tumoral cells derived from intercalated ducts or its progenitor cells, while in malignant salivary gland tumours EMA expression is, however, better used as an indicator of aggressive behavior than a marker of luminal cells.

Benign odontogenic ghost cell lesions revisited and new considerations on dysplastic dentin.

OBJECTIVES: This study aimed to revisit benign odontogenic ghost cell lesions (BOGCL) by hematoxylin and eosin staining and immunohistochemistry. MATERIALS AND METHODS: Thirty cases of calcifying odontogenic cyst (COC) and 6 cases of dentinogenic ghost cell tumor (DGCT) were selected for histopathological and immunohistochemical analysis. Sections stained for cytokeratin (K) 14, K-19, amelogenin, collagen type 1 (COL-1), and dentin matrix acidic phosphoprotein 1 (DMP-1) were evaluated using qualitative analysis. Sections stained for Ki-67 and minichromosome maintenance protein-2 (MCM-2) were evaluated using semi-quantitative analysis. RESULTS: A morphologic overlap was noticed in all BOGCL. Moreover, no differences were detected in the expression of K-14 and K-19. The expression of proliferative markers Ki-67 and MCM-2 was similar between cystic and tumor lesions (p > .05). The presence of COL-1 and absence of amelogenin in the so-called dysplastic dentin, associated with its histologic pattern, suggest that this is in fact an enameloid-like tissue. CONCLUSIONS: The dysplastic dentin should be considered an enameloid-like tissue in these lesions. CLINICAL RELEVANCE: The similarity in histology, protein expression, and proliferative marker indices between COC and DGCT suggest that they are a sole entity and likely represent types of the same neoplasia.

Microvessel density and cell proliferation in juvenile ossifying fibroma: A comparative study with central ossifying fibroma.

Considered as an aggressive counterpart of central ossifying fibroma (OF), juvenile ossifying fibroma (JOF) is a benign fibro-osseous neoplasm characterized by an unpredictable destructive behavior, elevated morbidity, mutilating treatment and high potential for local recurrences. The aim of this study is to compare the analysis for cell proliferation and vascular markers between JOF and OF. Cell proliferation index was measured by Ki-67 and Mcm-2 expression and microvessel density (MVD) was obtained by the immunoexpression of CD34/CD105. We observed a reduced expression of vascular markers, where MVD for CD34 was significantly higher in JOF than in OF (p = 0.009), but no statistical difference was found for CD105. JOF and OF showed low expression for Ki-67 and Mcm-2 and no difference was noted between both, suggesting that other mechanisms such as anti-apoptotic and/or pro-autophagic pathways or even increased expression of matrix metalloproteinases may be responsible for the aggressiveness of JOF.

Mammaglobin and DOG-1 expression in polymorphous low-grade adenocarcinoma: an appraisal of its origin and morphology.

BACKGROUND: Polymorphous low-grade adenocarcinoma (PLGA) remains a diagnostic challenge for most pathologists due to its large spectrum of histological patterns. In this study, the expression of two new markers recently described for salivary gland tumors was studied in PLGA. METHODS: The morphology of 33 cases of PLGA was carefully evaluated using hematoxylin-and-eosin-stained sections and confirmed by immunohistochemistry for cytokeratin 7, vimentin, and S-100. Periodic acid-Schiff with diastase digestion was also used. The expression of mammaglobin and DOG-1 was carried out using the EnVision System. Mammaglobin was assessed according to the percentage of positively stained tumor cells, while DOG-1 was evaluated according to its presence and site. For MCM-2 and Ki-67, markers of proliferation, the labeling index of cell nuclei positivity was evaluated using total cell number. The ETV6-NTRK3 fusion was examined by fluorescence in situ hybridization analysis. RESULTS: The histological patterns of the tumor were classified as lobular or non-lobular. For the non-lobular pattern, tubular, cribriform, glomeruliform, trabecular, and papillary patterns were observed. Mammaglobin was present in all PLGA cases, and its expression was stronger (P = 0.01) in the lobular than in the non-lobular pattern. The expression of DOG-1 was present in the apical portion and cytoplasm of the cells. Proliferation markers were low for all cases independent of histological pattern. CONCLUSIONS: Polymorphous low-grade adenocarcinoma has been confirmed to originate from the intercalated duct and to feature high expression of mammaglobin in its lobular pattern resembling that of mammary secretory analogue carcinoma, except for the ETV6 gene rearrangement.

Homologous transplantation with fresh frozen bone for dental implant placement can induce HLA sensitization: a preliminary study.

It has been related in orthopedic surgeries the HLA sensitization. Thus, we evaluate if the use of fresh-frozen homologous bone (FFHB) for dental implant placement induce anti-HLA sensitization. Six patients were treated with FFHB corticocancellous block grafts. After 6 months, bone biopsies were harvested during implant placement to allow histomorphometric analysis. Vital mineralized tissue (VMT), non-vital mineralized tissue (NVMT) and non-mineralized tissue (NMT) were quantified histomorphometrically. Peripheral blood was collected from the patients before FFHB placement and 6 months after the surgery for anti-HLA analysis. The histomorphometric analysis showed the presence of VMT, NVMT and NMT in 45.56 ± 15.72 %, 14.16 ± 13.39 % and 40.29 ± 12.60 %, respectively. The baseline and 6 months postoperative CTs revealed bone thickness in the order of 5.66 ± 0.67 mm and 8.71 ± 1.52 mm (3.05 ± 1.39 mm). The anti-HLA analysis revealed that two of the six patients (33.3 %) became sensitized, however this was not associated with any FFHB incorporation loss (p > 0.05). A total of 24 implants were placed all of which were osseointegrated after 6 months. Although FFHB-related HLA sensitization does not appear to affect bone incorporation when treating insufficient bone thickness for implant placement, further follow-up is required to determine whether there is an association between HLA sensitization and long-term graft survival.

MARPE expander activation load with different configurations of extender arms heights: in-vitro evaluation.

OBJECTIVE: Evaluate the load mini-implants exert on the artificial bone when expanding the MARPE EX in three different extension arm configurations. METHODS: A device simulating the human palate was fabricated and attached to a universal testing machine, for conducting tests with different MARPE expanders (n=5): non-adjustable/control (MARPE SL, Peclab) or with low, intermediate, and high extender arms (MARPE EX, Peclab). The expanders were manually activated until failure of the device occurred, and maximum load values were recorded. Load averages were also calculated for every five activations until the twentieth activation. RESULTS: The generalized linear mixed model for repeated measures over time showed that there was significant increase in load with activations for all expanders (p=0.0004). Up to the twentieth activation, the expander with low extender arms presented higher load than the others, while the expander with high extender arms showed lower load values (p<0.05). There was no significant difference among expanders regarding the number of activations (p=0.0586), although there was a trend towards fewer activations until fracture for the control expander. It was observed that the higher the configuration, the lower the force the mini-implants delivered to the bone. The control expander provided a force magnitude similar to that of the adjustable expander when positioned at the intermediate height. CONCLUSIONS: The activation load of MARPE expanders is influenced by the type of presentation of the extensor arms, with higher configurations resulting in lower force delivered by the mini-implants to the bone.

In vitro evaluation of the suppressor potential of conditioned medium from benign myoepithelial cells from pleomorphic adenoma in malignant cell invasion.

Tumoral invasion process is the result of a complex interaction between the tumor cells and microenvironment which plays an important role in modulating the growth and invasion of the cancer. The myoepithelial cells, present in glandular organs such as the breast and salivary glands, seem to exert paracrine effects on the glandular epithelium, acting as natural tumor suppressors. To verify the influence of the benign myoepithelial cells in the invasion of malignant cells, simulating an in situ carcinoma ex pleomorphic adenoma, we have cultured three different high-potential invasive malignant tumors (breast ductal adenocarcinoma, melanoma and oral squamous cell carcinoma) in conditioned medium of myoepithelial cells from salivary gland pleomorphic adenomas using transwell chambers with 8-µm pores membrane coated with matrigel. After 96 h, quantitative analyses of the results were performed by calculating the invasion index (number of cells that invaded in relation to the total number of cells). The results showed that there was a reduction of the invasion index mean for the three different malignant tumors. This study supports a tumoral suppressor function of the myoepithelial cells from pleomorphic adenoma in in vitro invasion process.

Assessment of a Biosafety Device to Control Contamination by Airborne Transmission during Orthodontic/Dental Procedures.

During the COVID-19 pandemic, dental professionals have faced high risk of airborne contamination between dentists, staff, and patients. The objective of this study was to evaluate the effect of an individual biosafety capsule in dentistry (IBCD) on reducing the dispersion of droplets and aerosols during orthodontic treatment and evaluate the clinician and patient's perception of using the IBCD. For the in-vitro part of the study, aerosol quantification was performed with and without the IBCD, using a nonpathogenic bacterial strain and viral strain in the reservoir and high-speed dental handpiece. Petri dishes with MRS agar were positioned from the head of the equipment at distances of 0.5, 1, and 1.5 m. After 15 minutes of passive aerosol sampling, the dishes were closed and incubated using standard aerobic conditions at 37°C for 48 hours to count colony forming units (CFUs). For the clinical part of the study, a questionnaire was sent to clinicians and patients to understand their perception of orthodontically treat and receive treatment using the barrier. The use of IBCD showed an effective means to reduce the dispersion of bacterial and viral contamination around 99% and 96%, respectively, around the main source of aerosol (p < 0.05). Clinical results showed a 97% bacterial reduction during patient's consultations (p < 0.05). The vast majority of clinicians and patients understand the importance of controlling the airborne dispersion to avoid contamination.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips.

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 108 CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Influence of apical preparation size and final irrigation protocol on the debridement of oval root canals.

This study assessed the influence of apical preparation size and final irrigation protocol on the debridement of the apical third of oval root canals of mandibular molars. Seventy-seven distal roots were divided into 7 groups (n = 11): Control: without instrumentation or irrigation; Group 30CI: ProTaper Next (up to size 30; PTN) + conventional irrigation (CI); Group 30UAI: PTN + ultrasonically activated irrigation (UAI); Group 30XPF: PTN + XP-endo Finisher (XPF); Group 40CI: PTN + ProDesign Logic (up to size 40; PDL) + CI; Group 40UAI: PTN + PDL + UAI; and Group 40XPF: PTN + PDL + XPF. The total volume of irrigating solutions used per root canal in all the experimental groups was 33 mL of 2.5% sodium hypochlorite (NaOCl) and 6 mL of 17% ethylenediaminetetraacetic acid (EDTA). After specimen processing and histological analysis under a digital microscope (100x), the percentages of untouched canal walls (UCW) and remaining debris (RD) were assessed using Image J software. A descriptive and exploratory analysis was conducted, indicating that the data failed to meet the assumptions of an analysis of variance. Therefore, generalized linear models were used to assess the effects of the different instrumentation and irrigation protocols, as well as the interaction among them, on the percentage of UCW and RD. No significant difference was found among the irrigation protocols regarding the percentage of UCW, irrespective of apical preparation size (p>0.05). However, UCW and RD were significantly lower in groups 40CI, 40UAI and 40XPF than in groups 30CI, 30UAI and 30XPF (p<0.05). The percentage of RD was significantly lower in the UAI and XPF groups than in the CI groups, irrespective of apical preparation size (p<0.05). The difference between preparation sizes 30 and 40, with respect to RD, was higher when CI was used (p<0.05). In conclusion, instrumentation up to apical preparation size 40 resulted in lower percentages of UCW and RD than up to apical preparation size 30. Use of UAI or XPF resulted in lower percentages of RD than CI.

Biosafety devices to control the spread of potentially contaminated dispersion particles. New associated strategies for health environments.

Dental procedures produce a large amount of spatter and aerosols that create concern for the transmission of airborne diseases, such as Covid-19. This study established a methodology with the objective of evaluating new associated strategies to reduce the risk of cross-transmission in a health environment by simulating spread of potentially contaminated dispersion particles (PCDP) in the environment. This crossover study, was conducted in a school clinic environment (4 clinics containing 12 dental chairs each). As a positive control group (without barriers), 12 professionals activated at the same time the turbine of dental drill, for one minute, with a bacterial solution (Lactobacillus casei Shirota, 1.5x108 CFU/mL), which had been added in the cooling reservoir of the dental equipment. In the experimental groups, the professionals made use of; a) an individual biosafety barrier in dentistry (IBBD) which consists of a metal support covered by a disposable PVC film barrier; b) a Mobile Unit of Disinfection by Ultraviolet-C, consisting of 8 UV lamps-C of 95W, of 304µW/cm2 of irradiance each, connected for 15 minutes (UV-C) and; c) the association between the two methods (IBBD + UV-C). In each clinic, 56 Petri dishes containing MRS agar were positioned on the lamps, benches and on the floor. In addition, plates were placed prior to each test (negative control group) and plates were also placed in the corridor that connects the four clinics. In the groups without barrier and IBBD + UV-C the passive air microorganisms in Petri dishes was also evaluated at times of 30, 60, 90 and 120 minutes after the end of the dental's drill activation. The mean (standard deviation) of CFU of L. casei Shirota for the positive control group was 3905 (1521), while in the experimental groups the mean using the IBBD was 940 (466) CFU, establishing a reduction on average, of 75% (p<0.0001). For the UV-C group, the mean was 260 (309) CFU and the association of the use of IBBD + UV-C promoted an overall average count of 152 (257) CFU, establishing a reduction on average of 93% and 96%, respectively (p<0.0001). Considering these results and the study model used, the individual biosafety barrier associated with UV-C technology showed to be efficient strategies to reduce the dispersion of bioaerosols generated in an environment with high rate of PCDP generation and may be an alternative for the improvement of biosafety in different healthy environment.

Bilateral Sinonasal Inverted Papilloma: Report of an Uncommon Case Involving Sinuses of the Face and Orbital Cavity.

BACKGROUND Nasosinusal papilloma is a benign aggressive tumor. It usually occurs unilaterally in the nasal cavity and can extend to the sinuses. The diagnosis is made by the correlation of findings observed in tomographic and histopathological exams. The recommended treatment is surgical excision with clinical monitoring. Orbital involvement occurs in about 9% of cases of advanced SIP. However, there is no report of cases of a benign tumor that invaded the adjacent soft tissues. Therefore, our objective is to report an unusual case of SIP that bilaterally involved the nasal cavity and maxillary sinuses, and extended to involve the ethmoidal cells and sphenoid and frontal sinuses. CASE REPORT In this article, we report an unusual presentation of sinonasal inverted papilloma (SIP) in a 60-year-old man. The tumor bilaterally involved the nasal cavity and maxillary sinuses and extended to involve the ethmoidal cells and the sphenoid and frontal sinuses, as well as the orbital cavity on the right side. An open surgical procedure was performed for complete removal of the lesion and follow-up with imaging exams. CONCLUSIONS The involvement of these structures is uncommon in SIP. This highlights the importance of this case report. Diagnosis and surgical treatment must be carefully planned. In this work, we describe all the steps that helped guide the choice of the best surgical technique to be performed and offer the best clinical follow-up.

A rare case of invasive sinonasal carcinosarcoma.

INTRODUCTION: Carcinosarcomas are rare malignant neoplasms formed by embryonic tissues (ectoderm and mesoderm) and present remarkably aggressive character with unfavourable prognosis. These lesions are rarely diagnosed in the sinonasal cavity and only a few cases are reported in the literature. This manuscript aimed to report a rare case of a large and aggressive sinonasal carcinosarcoma that involved the facial middle third and to discuss the proposed treatment. PRESENTATION OF CASE: A 54-year-old female patient sought treatment for a large swelling on the left side of the face. A CT-scan revealed an expansive hypodense image in the facial middle third. An incisional biopsy was performed under local anaesthesia and the material was sent for histopathological analysis. DISCUSSION: Due to the extremely aggressive character of carcinosarcomas, the optimal management of carcinosarcomas remains uncertain and a challenge for clinicians. In this case report, the prognosis of such a large tumour became unfavourable since the patient sought late for treatment. Therefore, suspicion and early detection are crucial for improving the prognosis and quality of life of the patients with such neoplasia. CONCLUSION: Besides being rare and extremely aggressive, sinonasal carcinosarcomas present worse patient survival when compared to other carcinosarcomas in the head and neck region. Thus, this report may contribute to a better understanding of this tumour behaviour.

Role of apoptotic, autophagic and senescence pathways in minor salivary gland adenoid cystic carcinoma.

BACKGROUND: Adenoid cystic carcinoma (ACC) is a salivary gland malignancy with poor long-term survival, which warrants studies aimed at clarifying the pathogenesis of this disease in order to widen the scope of therapeutic options currently available. Alterations in regulatory mechanisms relating to vascular support, cell death and autophagy are important pathways for tumor growth in cancer. Thus, the present study aimed to access vascular supply, apoptosis, autophagy and cell senescence in ACC of minor salivary glands. METHODS: We analyzed 25 cases of minor salivary gland ACC by immunohistochemistry using anti-CD34, anti-CD105, anti-D2-40, anti-Bax, anti-Bcl-2, anti-Beclin-1, anti-LC3B, anti-p21 and anti-p16. RESULTS: Microvessel density was low and based on anti-CD34, anti-CD105 and anti-D2-40 immunostaining. There was positivity for anti-CD34, anti-Bcl-2, anti-Beclin, anti-LC3B and anti-p21 and a positive correlation between Bcl-2 and Beclin (p = 0.014). CONCLUSIONS: Our results showed that ACC does not depend on neo-angiogenesis and is probably associated to anti-apoptotic, autophagic and anti-senescence events.

PERCEPTIONS ON THE IMPORTANCE OF VACCINATION AND VACCINE REFUSAL IN A MEDICAL SCHOOL. / PERCEPÇÕES ACERCA DA IMPORTÂNCIA DAS VACINAS E DA RECUSA VACINAL NUMA ESCOLA DE MEDICINA.

OBJECTIVE: To identify the perception of medical students and physicians on the importance of vaccination and the risks of vaccine refusal. METHODS: Cross-sectional study with application of questionnaires about vaccines, vaccine refusal and its repercussions on public and individual health. A sample of 92 subjects was selected from a private medical school: group 1 (53 students from first to fourth grades) and group 2 (39 physicians). Data collected were tabulated in the Microsoft Excel Program and analyzed by Fisher's exact test. RESULTS: Both groups considered the National Immunization Program reliable and recognized the importance of vaccines, but 64.2% of students and 38.5% of physicians are unaware of the vaccine-preventable infectious diseases in the basic immunization schedule. Most of the interviewees had a personal vaccine registry, but not all had received the 2015 influenza vaccine. Both groups had known people who refused vaccines for themselves or for their children (respectively, 54.7 and 43.3% of students and 59.0 and 41.0% of physicians). The total of 48.7% of physicians had already assisted vaccine refusers. Appointed causes of vaccine refusal were: fear of adverse events, philosophical and religious reasons and lack of knowledge about severity and frequency of diseases. Ethical aspects of vaccine refusal and legal possibilities of vaccine requirements for children are not consensus. CONCLUSIONS: Medical students and doctors are not adequately vaccinated and have queries about the vaccination schedule, vaccine safety and vaccine refusal. Improving these professionals' knowledge is an important strategy to maintain vaccine coverage and address vaccine refusal ethically.

OBJETIVO: Identificar a percepção da importância das vacinas e os riscos da recusa vacinal entre alunos de Medicina e médicos. MÉTODOS: Estudo transversal realizado por meio da aplicação de questionários sobre vacinas, recusa vacinal e suas repercussões acerca da saúde pública e individual. A amostra, de 92 sujeitos, foi selecionada numa escola privada de Medicina: grupo 1 (53 estudantes do primeiro ao quarto ano) e grupo 2 (39 médicos). Os dados colhidos foram tabulados no programa Microsoft Excel e analisados estatisticamente com o teste exato de Fisher. RESULTADOS: Os dois grupos consideram o Programa Nacional de Imunizações confiável e reconhecem a importância das vacinas, mas 64,2% dos estudantes e 38,5% dos médicos desconhecem o número de doenças infecciosas evitáveis pelas vacinas no calendário básico. A maioria dos entrevistados possuía carteira de vacinas, mas nem todos receberam vacina influenza 2015. Conheciam pessoas que recusavam vacinas e/ou recusavam vacinar seus filhos (respectivamente, 54,7 e 43,3% dos estudantes e 59,0 e 41,0% dos médicos). Dos médicos, 48,7% já atenderam pacientes que se recusaram a receber vacinas. Consideram causas de recusa vacinal: medo de eventos adversos, razões filosóficas, religiosas e desconhecimento sobre gravidade e frequência das doenças. Aspectos éticos da recusa vacinal e possibilidades legais de exigir vacinas para crianças não são consenso. CONCLUSÕES: Alunos de Medicina e médicos não se vacinam adequadamente, apresentam dúvidas sobre calendário vacinal, segurança das vacinas e recusa vacinal. Melhorar sua capacitação é importante estratégia para manter as coberturas vacinais e abordar a recusa vacinal de forma ética.