Abstract This meta-analysis aimed to investigate the effects of propolis on the severity of coronavirus disease symptoms by reducing periodontal disease. PubMed, EMBASE, SciELO, Web of Science, and SCOPUS databases were systematically searched. Studies have been conducted analyzing propolis’s effects on COVID-19 and periodontitis. The study was conducted according to the PRISMA statement and registered in PROSPERO. Risk of Bias (RoB) assessment and meta-analysis of clinical studies were performed (Review Manager 5, Cochrane). The certainty of the evidence was assessed using GradePro (GDT). Studies have shown propolis flavonoids inhibit viral replication in several DNA and RNA viruses, including coronaviruses. Propolis components have an aminopeptidase inhibitor activity that can inhibit the main proteases of SARS viruses and seem to inhibit protein spikes, which are sites of most mutations in SARS-CoV strains. The meta-analysis showed favorable results with the use of propolis on probing depth (95%CI: 0.92; p < 0.001), clinical attachment level (95%CI: 1.48; p < 0.001), gingival index (95%CI: 0.14; p = 0.03), plaque index (95%CI: 0.11; p = 0.23), and blending on probing (95%CI: 0.39; p < 0.001). The antibacterial activity of propolis could be mediated through its direct action on microorganisms or the stimulation of the immune system, activating natural defenses. Thus, propolis inhibits the replication of SARS-CoV-2 as well as its bacterial activity. Treatment with propolis improves general health and facilitates the activation of the immune system against coronavirus. metaanalysis meta analysis PubMed EMBASE SciELO Science searched propoliss s COVID19 COVID 19 COVID-1 periodontitis PROSPERO RoB (RoB Review 5 Cochrane. Cochrane . Cochrane) GDT. GDT (GDT) coronaviruses spikes SARSCoV CoV strains 95%CI 95CI CI 95 (95%CI 0.92 092 0 92 0.001, 0001 0.001 , 001 0.001) 1.48 148 1 48 0.14 014 14 0.03, 003 0.03 03 0.03) 0.11 011 11 0.23, 023 0.23 23 0.23) 0.39 039 39 0.001. defenses Thus SARSCoV2 2 SARS-CoV- COVID1 COVID- (GDT 9 0.9 09 000 0.00 00 1.4 4 0.1 01 0.0 02 0.2 0.3 3 0. 1.

Abstract Considering the unfavorable implications of health falsehoods and the lack of dental research into information disorder, this study aimed to identify and characterize online oral health misinformation. A total of 410 websites published in English were retrieved using Google Advanced Search and screened by two independent investigators to compile falsehoods through thematic content analysis. Afterward, 318 pieces of misinformation were consensually divided into four groups concerning their informational interest (G1), financial, psychological, and social interests produced/disseminated by non-dental professionals (G2) or by dental professionals (G3), and political interests (G4). Social media (Facebook and Instagram) and fact-checking tool (Snopes) were also screened to determine the spread of falsehoods by identifying corresponding posts and warnings. As a result, misinformation was mainly associated with gum diseases (12.0%), root canal treatment (11.6%), toothache (10.4%), fluoride (10.4%), and dental caries (9.8%), with a special highlight on recommendations for the usage of natural products, toxicity concerns, and anti-fluoridation propaganda. Additionally, most misinformation was allocated in G3 (41.9%), which presented a statistically higher frequency of financial interests than G4. Finally, falsehoods were considerably identified on Facebook (62.9%) and Instagram (49.4%), especially G3 and G4. Nevertheless, Snopes has debunked only 5.9% of these content items. Therefore, misinformation was predominantly produced or disseminated by dental professionals mainly motivated by financial interests and usually linked to alternative/natural treatments. Although these items were shared on social media, fact-checking agencies seemed to have limited knowledge about their dissemination. disorder 41 analysis Afterward 31 G1, G1 G , (G1) psychological produceddisseminated nondental non G2 (G2 G3, (G3) G4 . (G4) factchecking fact checking (Snopes warnings result 12.0%, 120 12.0% 12 0 (12.0%) 11.6%, 116 11.6% 11 6 (11.6%) 10.4%, 104 10.4% 10 4 (10.4%) 9.8%, 98 9.8% 9 8 (9.8%) products concerns antifluoridation anti fluoridation propaganda Additionally 41.9%, 419 41.9% (41.9%) Finally 62.9% 629 62 (62.9% 49.4%, 494 49.4% 49 (49.4%) Nevertheless 59 5 5.9 Therefore alternativenatural alternative treatments dissemination 3 (G1 (G (G3 (G4 12.0 1 (12.0% 11.6 (11.6% 10.4 (10.4% 9.8 (9.8% 41.9 (41.9% 62.9 (62.9 49.4 (49.4% 5. 12. (12.0 11. (11.6 10. (10.4 9. (9.8 41. (41.9 62. (62. 49. (49.4 (12. (11. (10. (9. (41. (62 (49. (12 (11 (10 (9 (41 (6 (49 (1 ( (4

Resumo Objetivos: este estudo revisou sistematicamente a literatura para melhor compreender a associação entre COVID-19, gravidez e neonatos. Métodos: MEDLINE, EMBASE, Web of Science, BVS e SCOPUS foram acessadas, considerando os termos: (covid 19 OR covid-19 OR novel coronavirus OR 2019 novel coronavirus OR 2019-nCoV OR sarscov 2 OR sars-cov-2 OR sarscov2 OR sars cov-2) AND (pregnancy OR pregnant OR pregnant women OR gestation OR gestational) AND (infant OR fetal OR neonatal). Trinta textos completos foram incluídos (408 gestantes, 11 mulheres nãogestantes e 279 recém-nascidos). Resultados: febre (45,83%) e tosse (31,61%) foram os principais sintomas da COVID-19 durante a gestação. Baixos níveis de linfócitos (32,10%), elevados níveis de proteínas Creativa (32,35%); leucocitose (29,41%); neutrófilo (5,88%); e alterações radiográficas sob tomografia computadorizada de tórax, radiografia ou ultrasom (45,84%) foram os principais achados laboratoriais. Parto por cesárea e prematuridade foram registrados em 239 e 49 casos, respectivamente. Dez recém-nascidos testaram positivo para o virus SARS-CoV-2. Conclusão: quando a pneumonia COVID-19 afeta mulheres durante a gravidez, os sintomas são semelhantes aos experimentados por mulheres não grávidas. Além disso, ainda não há evidências plausíveis que sugiram a transmissão vertical do vírus SARS-CoV-2 de mãe para filho.

Abstract Objectives: this study systematically reviewed the literature in order to better understand the association among COVID-19, pregnancy and neonates. Methods: MEDLINE, EMBASE, Web of Science, BVS and SCOPUS were assessed, considering the terms: (covid 19 OR covid-19 OR novel coronavirus OR 2019 novel coronavirus OR 2019-nCoV OR sarscov 2 OR sars-cov-2 OR sarscov2 OR sars cov-2) AND (pregnancy OR pregnant OR pregnant women OR gestation OR gestational) AND (infant OR fetal OR neonatal). Thirty full-text were included (408 pregnant women, 11 non-pregnant women and 279 neonates). Results: fever (45.83%) and cough (31.61%) were the main symptoms of COVID-19 during the pregnancy. Low levels of lymphocytes (32.10%), elevated levels of C-reactive protein (32.35%); leukocytosis (29.41%); neutrophil (5.88%); and radiographic alterations on chest CT, x-ray or ultrasound (45.84%) were the main laboratorial findings. Cesarean delivery and preterm were registered in 239 and 49 cases, respectively. Ten neonates tested positive for SARS-CoV-2. Conclusion: when COVID-19 pneumonia affects women during pregnancy, the symptoms are similar to those experienced by non-pregnant women. In addition, there is still no plausible evidence suggesting vertical transmission of SARS-CoV-2 virus from mother to child.

Abstract Objectives This study shows the development and validation of a dental anesthesia-training simulator, specifically for the inferior alveolar nerve block (IANB). The system developed provides the tactile sensation of inserting a real needle in a human patient, using Virtual Reality (VR) techniques and a haptic device that can provide a perceived force feedback in the needle insertion task during the anesthesia procedure. Material and Methods To simulate a realistic anesthesia procedure, a Carpule syringe was coupled to a haptic device. The Volere method was used to elicit requirements from users in the Dentistry area; Repeated Measures Two-Way ANOVA (Analysis of Variance), Tukey post-hoc test and averages for the results’ analysis. A questionnaire-based subjective evaluation method was applied to collect information about the simulator, and 26 people participated in the experiments (12 beginners, 12 at intermediate level, and 2 experts). The questionnaire included profile, preferences (number of viewpoints, texture of the objects, and haptic device handler), as well as visual (appearance, scale, and position of objects) and haptic aspects (motion space, tactile sensation, and motion reproduction). Results The visual aspect was considered appropriate and the haptic feedback must be improved, which the users can do by calibrating the virtual tissues’ resistance. The evaluation of visual aspects was influenced by the participants’ experience, according to ANOVA test (F=15.6, p=0.0002, with p<0.01). The user preferences were the simulator with two viewpoints, objects with texture based on images and the device with a syringe coupled to it. Conclusion The simulation was considered thoroughly satisfactory for the anesthesia training, considering the needle insertion task, which includes the correct insertion point and depth, as well as the perception of tissues resistances during the insertion.

Abstract Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is able to increase salivary calcium and phosphate levels at an acidic pH. Previous studies demonstrated that a CPP-ACP chewing gum was able to enhance the re-hardening of erosion lesions, but could not diminish enamel hardness loss. Therefore, there is no consensus regarding the effectiveness of CPP-ACP on dental erosion. Objective This in situ study investigated the ability of a CPP-ACP chewing gum in preventing erosive enamel loss. Material and Methods: During three experimental crossover phases (one phase per group) of seven days each, eight volunteers wore palatal devices with human enamel blocks. The groups were: GI – Sugar free chewing gum with CPP-ACP; GII – Conventional sugar free chewing gum; and GIII – No chewing gum (control). Erosive challenge was extraorally performed by immersion of the enamel blocks in cola drink (5 min, 4x/day). After each challenge, in groups CPP and No CPP, volunteers chewed one unit of the corresponding chewing gum for 30 minutes. Quantitative analysis of enamel loss was performed by profilometry (µm). Data were analyzed by Repeated-Measures ANOVA and Tukey’s test (p<0.05). Results The use of chewing gum (CPP and No CPP) resulted in lower erosive enamel loss compared with the control group (p<0.05). CPP-ACP chewing gum (CPP) did not improve the protection against erosive enamel loss compared with conventional chewing gum (No CPP) (p>0.05). Conclusion The CPP-ACP chewing gum was not able to enhance the anti-erosive effect of conventional chewing gum against enamel loss.

Abstract This study aimed at monitoring the maxillary growth of children with cleft lip/palate in the first two years of life, and to evaluate the effects of primary surgeries on dental arch dimensions. The sample consisted of the three-dimensional digital models of 25 subjects with unilateral complete cleft lip and palate (UCLP) and 29 subjects with isolated cleft palate (CP). Maxillary arch dimensions were measured at 3 months (before lip repair), 1 year (before palate repair), and at 2 years of age. Student’s ttest was used for comparison between the groups. Repeated measures ANOVA followed by Tukey’s test was used to compare different treatment phases in the UCLP group. Paired ttest was used to compare different treatment phases in the CP group. P<0.05 was considered statistically significant. Decreased intercanine distance and anterior arch length were observed after lip repair in UCLP. After palate repair, maxillary dimensions increased significantly, except for the intercanine distance in UCLP and the intertuberosity distance in both groups. At the time of palate repair and at two years of age, the maxillary dimensions were very similar in both groups. It can be concluded that the maxillary arches of children with UCLP and CP changed as a result of primary surgery.

Abstract In this Point-of-view article we highlighted some features related to saliva and virus infection, in special for zika virus. In addition, we pointed out the potential oral problems caused by a microcephaly originated by a zika virus infection. In the end the, we demonstrated the importance of a more comprehensive exploration of saliva and their components as a fluid for diagnostic and therapeutic approaches on oral and systemic diseases.

Resumo Os objetivos deste trabalho foram avaliar e comparar por 24 meses, a retenção e as características superficiais de dois diferentes materiais seladores, Helioseal Clear e Helioseal F(Ivoclar Vivadent). A correlação entre os diferentes graus de erupção e a retenção dos selantes também foram verificadas. Cinquenta crianças de 6 a 8 anos de idade participaram deste estudo, totalizando de 153 dentes divididos em dois grupos: HC (Helioseal Clear) e HF (Helioseal F). Após 6, 12, 18 e 24 meses, avaliação clínica foi realizada por dois examinadores calibrados. As caracterísiticas superficiais e a retenção (critério modificado de Ryge &Snyder) foram avaliadas. A análise da superfície oclusal, o HC demostrou retenção estatisticamente significante maior para os 12 meses (p=0,0345) e 24 meses (p=0,0076). Em relação às características superficiais, somente para descoloração superficial, o HC foi menor que do HF, durante o período estudado. Para as demais características, os resultados do teste de Mann-Whitney foram altamente significantes para HC em diferentes períodos (p=0,0000 a 0,0421). A frequência de bolhas nas superfícies seladas, determinada pelo teste do Qui-quadrado, foi maior e mais significante no HF (p=0,000:12 e 18 meses a p=0,002: 6 e 24 meses). O selante HC apresentou melhor desempenho à retenção e características superficiais.

The aim of this study was to evaluate and compare for 24 months, the retention and surface characteristics of two pit-and-fissure sealants: Helioseal Clear and Helioseal F (Ivoclar Vivadent). The correlation between the different stages of eruption and sealant retention was also verified. Fifty children aged 6 to 8 years participated in the study, totalizing 153 teeth divided into two groups: HC (Helioseal Clear) and HF (Helioseal F). After 6, 12, 18 and 24 months, a clinical examination was performed by previously calibrated examiners. The surface characteristics and the retention of the sealants (modified RYGE & SNYDER criteria) were assessed. Analyzing the occlusal surface, HC exhibited a statistically significant higher retention at 12 (p=0.0345) and 24 months (p=0.0076). Concerning the surface characteristics, only the superficial discoloration of HC was smaller than HF, during the entire studied period. For all the other characteristics, the results of the Mann-Whitney test were highly significant at different periods (p=0.0000 to 0.0421). The frequency of air bubbles within the sealant surfaces, determined by Chi-square test, was significantly higher in HF (p=0.000:12 and 18 months to p=0.002: 6 and 24 months). HC sealant material exhibited the best performance regarding the retention and surface characteristics on the occlusal surface.

Gemination in bilateral mandibular primary teeth is a rare anomaly. This kind of anomaly features two crowns totally or partially separated, but only one root and one root canal. At intraoral clinical examination of children we found different anatomy of mandibular primary canines with two partially separated crowns. The radiographic exams showed geminated teeth. After 3-years of follow-up, the cone beam computed tomography showed the absence of the mandibular permanent lateral incisors and the aspect of normality of the permanent canines germs. Although the gemination in primary teeth itself is considered as a harmless anomaly, its presence could indicate the occurrence of some dental anomaly in the permanent dentition. To the best of our knowledge, this is the only case of bilateral mandibular geminated deciduous teeth after 3 years of follow-up. Therefore, we highlight the importance of the early diagnosis and follow-up of this anomaly until the eruption of the permanent dentition.

La geminación dientes temporales mandibulares bilateralmente es una anomalía poco frecuente. Este tipo de anomalía presenta dos coronas total o parcialmente separadas, pero solo una raíz y un canal radicular. Al examen clínico intraoral de los niños encontramos la variación anatómica de los caninos temporales mandibulares con dos coronas parcialmente separadas. Los exámenes radiográficos mostraron los dientes geminados. Después de 3 años de seguimiento, la tomografía computarizada Cone-Beam mostró la agenesia de los incisivos laterales permanentes mandibulares y el aspecto de normalidad de los gérmenes de los caninos permanentes. Aunque la geminación en dientes primarios se considera como una anomalía no patológica, su presencia puede indicar la presencia de alguna anomalía dental en la dentición permanente. Según nuestro nuestro conocimiento, este es el único caso de dientes temporales geminados mandibulares bilateralmente tras 3 años de seguimiento. Se destaca la importancia del diagnóstico precoz y el seguimiento de esta anomalía hasta la erupción de la dentición permanente.

AIM: The primary aim of this longitudinal study was to evaluate additional effects of 4-week chlorhexidine digluconate (CHX) gel treatments to control Aggregatibacter actinomycetemcomitans counts in children after professional dental prophylaxis. Porphyromonas gingivalis and Streptococcus mutans counts were also determined to evaluate the secondary effects of anti-plaque treatments on microbial shifts. METHODS: Twenty-six children with A. actinomycetemcomitans counts >4 log10/mL of saliva and/or Quigley-Hein plaque index >3.0 were enrolled in this study. Patients were randomly assigned to groups GI (placebo gel), GII (0.5% CHX gel), GIII (1% CHX gel), and GIV (2% CHX gel). Four sessions of treatment were performed during 4 weeks after a session of professional dental prophylaxis. Real-Time polymerase chain reaction (PCR) was used to determine viable microorganism counts in non-stimulated whole saliva samples collected at baseline, one week, one month and three months after interruption of treatments. RESULTS: A reduction of all bacterial counts was detected after the 3-month follow-up in all groups. Lower counts of P. gingivalis were achieved from 1 week on after treatments. The 2% CHX concentration seemed to contribute to lower A. actinomycetemcomitans levels and increase S. mutans levels. CONCLUSIONS: Professional dental prophylaxis was effective to control salivary levels of A. actinomycetemcomitans, P. gingivalis and S. mutans. Additional antimicrobial effects, however, were not observed by the combination of professional dental prophylaxis and 4-week chlorhexidine gel treatments.

INTRODUÇÃO: A pulpotomia em dentes decíduos é uma técnica conservadora de terapia pulpar amplamente utilizada em Odontopediatria, sendo de fundamental importância para evitar a perda prematura desses dentes, quer seja por alterações provocadas pela cárie dentária ou traumatismo dentário. Apesar de ser uma técnica estudada há muitos anos, causa muitas controvérsias e discussões, principalmente em termos de biocompatibilidade dos medicamentos empregados e pelas dificuldades e falhas no diagnóstico da condição pulpar. OBJETIVO: Por meio de uma revisão sistemática da literatura, no período compreendido entre 2000 e 2011, e com enfoque em estudos clínicos randomizados, revisões sistemáticas e meta-análises, este trabalho teve como objetivo discutir, com base em evidências científicas, alternativas para o tratamento de pulpotomia em dentes decíduos humanos. CONCLUSÃO: As evidências científicas fidedignas com o uso de materiais capeadores pulpares e as técnicas de Eletrocirurgia e Laser de Baixa Potência foram escassas. Desta forma, sugere-se a realização de estudos complementares bem delineados estatisticamente para maiores esclarecimentos. As informações geradas em tais experimentos poderão contribuir para um melhor entendimento dos mecanismos da terapia pulpar, podendo gerar o desenvolvimento de protocolos com novas formas terapêuticas, que visam a melhorar a terapia pulpar em dentes decíduos.

INTRODUCTION: Pulpotomy of primary teeth has been the treatment of choice in cases of inflammation of the coronal pulp caused by caries or trauma with no involvement of the radicular pulp, thus avoiding the premature loss of the teeth. Not only is the diagnosis of the inflamed dental pulp required for this therapy to succeed, but also the selection of an effective and biocompatible medicament. However, none of the drugs available and recommended for pulpotomy therapy present all the requirements of an ideal pulp capping agent. OBJECTIVE: Through a systematic literature review, between the years of 2000 and 2011, focusing in randomized clinical trials, systematic reviews and meta-analysis, aiming to analyze and discuss based on alternatives for the treatment of pulpotomy in human deciduous teeth. CONCLUSION: Scientific evidences showed that the medicaments and techniques influence were few. Thus, further and well-designed studies are suggested for clarification. The information generated in such experiments may contribute to a better understanding of the mechanisms of pulp therapy to new therapeutic approaches aimed at improving pulp therapy in deciduous teeth.

SHED (stem cells from human exfoliated deciduous teeth) represent a population of postnatal stem cells capable of extensive proliferation and multipotential differentiation. Primary teeth may be an ideal source of postnatal stem cells to regenerate tooth structures and bone, and possibly to treat neural tissue injury or degenerative diseases. SHED are highly proliferative cells derived from an accessible tissue source, and therefore hold potential for providing enough cells for clinical applications. In this review, we describe the current knowledge about dental pulp stem cells and discuss tissue engineering approaches that use SHED to replace irreversibly inflamed or necrotic pulps with a healthy and functionally competent tissue that is capable of forming new dentin.

O presente estudo teve como objetivo comparar o padrão de liberação de fluoreto (F-) de um cimento de ionômero de vidro (CIV) nanoparticulado modificado por resina (Ketac N100 - KN) com CIVs disponíveis na prática clínica (CIV modificado por resina - Vitremer - V; CIV convencional - Ketac Molar - KM) e uma resina composta nanoparticulada (Filtek Supreme - RC). Discos de cada material (n=6) foram imersos em 4 mL de água deionizada em frascos de polietileno e agitados durante 15 dias. A liberação de F- (μg F-/cm²) foi medida a cada dia utilizando um eletrodo de F- específico. Os valores de liberação cumulativa de F- foram analisados estatisticamente por análise de regressão linear. Com o objetivo de analisar as diferenças entre os materiais e a influência do tempo na liberação diária de F- foi aplicado o teste ANOVA a dois critérios (α=0,05). A relação entre os padrões de liberação de cumulativo de F- da RC e KM e o tempo foram fracas. Os materiais KN e V apresentaram uma relação forte entre a liberação cumulativa de F- e o tempo. Diferenças significativas foram observadas entre a liberação diária de F- até o terceiro dia somente para os cimentos ionoméricos. Os resultados indicam que o padrão de liberação de F- do CIV modificado por resina nanoparticulado é semelhante ao CIV modificado por resina.

The present study aimed to compare the fluoride (F-) release pattern of a nanofilled resin-modified glass ionomer cement (GIC) (Ketac N100 - KN) with available GICs used in dental practice (resin-modified GIC - Vitremer - V; conventional GIC - Ketac Molar - KM) and a nanofilled resin composite (Filtek Supreme - RC). Discs of each material (n=6) were placed into 4 mL of deionized water in sealed polyethylene vials and shaken, for 15 days. F- release (μg F-/cm²) was measured each day using a fluoride-ion specific electrode. Cumulative F- release means were statistically analyzed by linear regression analysis. In order to analyze the differences among materials and the influence of time in the daily F- release, 2-way ANOVA test was performed (α=0.05). The linear fits between the cumulative F- release profiles of RC and KM and time were weak. KN and V presented a strong relationship between cumulative F- release and time. There were significant differences between the daily F- release overtime up to the third day only for GICs materials. The daily F- release means for RC were similar overtime. The results indicate that the F- release profile of the nanofilled resin-modified GIC is comparable to the resin-modified GIC.

This study evaluated the superficial microhardness of enamel in teeth at different posteruptive ages (before eruption in the oral cavity, 2-3 years after eruption, 4-10 years after eruption and more than 10 years after eruption). The study sample was composed of 134 specimens of human enamel. One fragment of each tooth was obtained from the flattest central portion of the crown to produce specimens with 3 x 3 mm. The enamel blocks were minimally flattened out and polished in order to obtain a flat surface parallel to the base, which is fundamental for microhardness testing. Microhardness was measured with a microhardness tester and a Knoop diamond indenter, under a static load of 25 g applied for 5 seconds. Comparison between the superficial microhardness obtained for the different groups was performed by analysis of Student's t test. The results demonstrated that superficial microhardness values have a tendency to increase over the years, with statistically significant difference only between unerupted enamel and that with more than 10 years after eruption. According to the present conditions and methodology, it was concluded that there were differences between the superficial micro-hardness of specimens at different eruptive ages, revealing an increasing mineralization. However, this difference was significant only between unerupted specimens and those with more than 10 years after eruption.

This in situ study investigated, using scanning electron microscopy, the effect of stimulated saliva on the enamel surface of bovine and human substrates submitted to erosion followed by brushing abrasion immediately or after one hour. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 minutes in 150 ml of a cola drink, 4 times a day (8h00, 12h00, 16h00 and 20h00). Immediately after the immersions, no treatment was performed in 4 specimens (ERO), 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice and the device was replaced into the mouth. After 60 min, the other 4 specimens were brushed. In the second phase, the procedures were repeated but, after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Enamel superficial alterations of all specimens were then evaluated using a scanning electron microscope. Enamel prism core dissolution was seen on the surfaces submitted to erosion, while on those submitted to erosion and to abrasion (both at 0 and 60 min) a more homogeneous enamel surface was observed, probably due to the removal of the altered superficial prism layer. For all the other variables - enamel substrate and salivary stimulation -, the microscopic pattern of the enamel specimens was similar.