Abstract Resin composites containing surface pre-reacted glass (S-PRG) have been introduced to reduce demineralization and improve remineralization of the tooth structure. However, water diffusion within the material is necessary for its action, which can impair its overall physicomechanical properties over time, including color stability. This study aimed to evaluate the color stability and related degree of conversion (DC) of four resin composites. Discs (6 x 4 mm, n = 5/group) of microhybrid (MH), nanofilled (NF), nanohybrid (NH), and S-PRG-based nanohybrid (S-PRG-NH) composites with two opacities (A2/A2E and A2O/A2D) were prepared. Color (CIELab and CIEDE2000) was evaluated with a spectrophotometer after aging in grape juice (2 x 10 min/10mL/7days). The DC was analyzed by using Fourier transform infrared spectroscopy before and after light-curing. Data were statistically analyzed by using two-way analysis of variance and post-hoc least significant difference tests (p<0.05). In the color stability analysis, the interaction between filler type and opacity was significant (CIELab, p = 0.0015; CIEDE2000, p = 0.0026). NH presented the highest color stability, which did not differ from that of MH. The greatest color alteration was observed for S-PRG-NH. S-PRG fillers also influenced DC (p < 0.05). The nanohybrid resin composite presented favorable overall performance, which is likely related to its more stable organic content. Notwithstanding the benefits of using S-PRG-based nanohybrid resins, mostly in aesthetic procedures, professionals should consider the susceptibility of such resins to color alteration, probably due to the water-based bioactive mechanism of action. prereacted pre reacted SPRG S PRG (S-PRG structure However action time (DC 6 ( mm 5/group 5group group 5 MH, MH , (MH) NF, NF (NF) NH, (NH) SPRGbased based SPRGNH (S-PRG-NH A2/A2E A2A2E AAE A2 A2E A E A2O/A2D A2OA2D AOAD A2O A2D O D prepared CIELab CIEDE2000 CIEDE 2 1 min/10mL/7days. min10mL7days minmLdays min/10mL/7days . min 10mL 7days mL days min/10mL/7days) lightcuring. lightcuring light curing. curing light-curing twoway way posthoc post hoc p<0.05. p005 p<0.05 0 05 (p<0.05) CIELab, 0.0015 00015 0015 0.0026. 00026 0.0026 0026 0.0026) SPRGNH. NH. S-PRG-NH 0.05. 005 0.05 0.05) performance content procedures waterbased (MH (NF (NH AE OA AO AD CIEDE200 p00 p<0.0 (p<0.05 0.001 0001 001 0002 0.002 002 00 0.0 CIEDE20 p0 p<0. (p<0.0 0.00 000 0. CIEDE2 p<0 (p<0. p< (p<0 (p<

Abstract Objectives This study aimed to assess the effect of proanthocyanidin, palm oil and vitamin E against erosive and erosive+abrasive challenges in vitro after enamel pellicle formation in situ. Methodology Bovine enamel blocks (n=84) were obtained and divided into the following treatment groups: negative control (NC) - deionized water; positive control (PC) - SnCl2/NaF/AmF-containing solution; palm oil (PO); 2% proanthocyanidin (P2); vitamin E (VitE); 2% proanthocyanidin+palm oil (P2PO); and 2% proanthocyanidin+vitamin E (P2VitE). For 5 days, one half of the sample from each group was subjected to erosion and the other half was subjected to erosion+abrasion. The acquired enamel pellicle (AEP) was pre-formed in situ for 30 minutes. The specimens were then treated in vitro with solutions (500 µl, 30s for each group). Subsequently, the blocks were left in the oral cavity for another hour to obtain the modified AEP. The blocks were immersed in 0.5% citric acid (pH=2.5) for 90s, 4×/day. AEP formation and treatment were carried out before the first and third erosive challenges, and after these challenges, abrasive cycles (15s) were performed on half of the samples. Enamel wear was quantified by profilometry and data were analyzed by two-way ANOVA and Tukey’s test (p<0.05). Results All groups showed higher wear when exposed to erosion+abrasion than when exposed to erosion alone (p=0.0001). PO, P2VitE, P2, and P2PO showed enamel wear similar to the PC group, but only PC, PO and P2VitE differed from the NC group. The other groups behaved similarly to NC. Conclusion It was concluded that the combination of proanthocyanidin and vitamin E was effective in reducing wear in the face of in vitro erosive and erosive+abrasive challenges. erosiveabrasive n=84 n84 n 84 (n=84 (NC water (PC SnCl2/NaF/AmFcontaining SnCl2NaFAmFcontaining SnClNaFAmFcontaining SnCl2/NaF/AmF containing SnCl2 NaF AmF SnCl solution (PO) 2 P2 P (P2) VitE (VitE) proanthocyanidinpalm PPO (P2PO) proanthocyanidinvitamin P2VitE. PVitE . (P2VitE) days erosionabrasion abrasion (AEP preformed pre formed 3 minutes 500 (50 µl s group) Subsequently 05 0 0.5 pH=2.5 pH25 pH (pH=2.5 90s 4day day 4 4×/day 15s (15s samples twoway two way Tukeys Tukey p<0.05. p005 p p<0.05 (p<0.05) p=0.0001. p00001 p=0.0001 0001 (p=0.0001) n=8 n8 8 (n=8 AmFcontaining NaFAmFcontaining SnCl2NaFAmF SnClNaFAmF (PO (P2 (VitE (P2PO (P2VitE 50 (5 0. pH=2. pH2 (pH=2. p00 p<0.0 (p<0.05 p0000 p=0.000 000 (p=0.0001 n= (n= NaFAmF (P ( pH=2 (pH=2 p0 p<0. (p<0.0 p000 p=0.00 00 (p=0.000 (n pH= (pH= p<0 (p<0. p=0.0 (p=0.00 (pH p< (p<0 p=0. (p=0.0 (p< p=0 (p=0. (p p= (p=0 (p=

Abstract Objective: To classifying the degree of swallowing impairment in the elderly, comparing clinical and instrumental assessment. Methods: This is a cross-sectional study with quantitative and qualitative analysis of clinical and instrumental assessment of 37 elderly, aged 60 -82 years, of both genders without neurological, oncological or systemic diseases, participated in this study. All participants were submitted to clinical evaluation and their results compared through fiberoptic endoscopic evaluation of swallowing considering liquid, pudding and solid food consistencies. Data were analyzed descriptively and statistically using the analysis of variance test (two-way ANOVA) and Tukey’s post hoc test (p< 0.05). Results: In the clinical evaluation there was a higher occurrence of moderate swallowing impairment, followed by functional swallowing, while in fiberoptic endoscopic evaluation of swallowing the severity of the impairment was greater for moderate and mild degrees. There was no statistical difference between the clinical and instrumental evaluation methods. However, there was a significant interaction between the variables, with a difference for liquid consistency in the instrumental evaluation method. Conclusion: Healthy elderly have different degree of swallowing impairment according to food consistency. The clinical assessment using a scale that considers the physiological changes of the elderly, presented results similar to those found in the instrumental examination. Level of Evidence: 2. Objective Methods crosssectional cross sectional 3 6 82 -8 years neurological diseases consistencies twoway two way ANOVA Tukeys Tukey s p< p (p 0.05. 005 0.05 . 0 05 0.05) Results degrees methods However variables method Conclusion examination Evidence 2 8 - 00 0.0 0.

Abstract This study aimed to identify the prevalence of molar-incisor hypomineralization (MIH) in schoolchildren and its association with dental caries experience. This was a cross-sectional study with a sample of 471 children aged 8 to 10 years. Data were collected via a sociodemographic questionnaire. Intra-oral clinical examination was done to identify and diagnose MIH (EAPD Criteria) as well as dental caries (ICDAS Index). Statistical analyses were performed with Person’s Chi-square, Fisher’s exact, and Mann-Whitney tests, and Poisson regression models were built. Statistical significance was set at an alpha-level of 0.05. The prevalence of MIH in our participants was 9.8%, with lesions being mostly of the mild form (65.2%) and affecting the first permanent molars but not the incisors in 54.2% of the children. Dental caries was observed in 88.1% of subjects. We observed a significant association between dental caries and the following variables: presence of MIH (p < 0.01; PR = 1.13), dental visit (p < 0.02; PR=0.92), and parents or legal guardians’ education level (p < 0.05; PR = 1.07). A MIH diagnosis was also significantly associated with family income (p < 0.05; PR = 4.09). Children with MIH had more caries lesions on molar surfaces (p < 0.01; PR = 4.05). The prevalence of MIH was found to be moderate, based on previous studies, and the presence of enamel defect was associated with dental caries. The teeth most affected by MIH lesions were the first permanent molars.

Abstract Isthmuses are reported as common anatomic complexities in teeth often associated with failures in endodontic treatment. They should be considered before starting treatment and a preoperative computed tomography scan (CT) may demonstrate these complexities. Objective To assess the diagnostic value of the highest resolution settings of a cone-beam CT (CBCT) system in identifying and measuring apical isthmuses, using micro-CT as reference. Methodology After micro-CT scanning, 40 humans’ lower first molars with isthmuses in the apical-3 mm of mesial roots were scanned by the highest resolution settings of the New Generation i-Cat ® CBCT equipment. Two blinded observers recorded the detection of isthmuses in CBCT scans. The lengths of isthmuses were compared between micro-CT and CBCT to assess the diagnostic value of CBCT. Quantitative data for sensitivity were represented as percentages (95% confidence interval). The Bland-Altman method was used to assess differences between gold standard lengths (micro-CT) and CBCT lengths. Results BCT demonstrated 30 positive findings, representing sensitivity for isthmus identification of 75% (95% CI=0.4114–1.1364). Differences between the lengths in micro-CT (1.99±0.40 mm) and CBCT (1.53±0.41 mm) were significant (p<0.0001). Conclusion The CBCT device used presented limited diagnostic value in the identification and measurement of apical isthmuses in the mesial roots of lower molars. In some cases, the actual anatomy of the apical root canal may not be completely delineated in this type of CBCT system, even using the highest resolution settings.

ABSTRACT Objective: To verify the effectiveness of a nursing training program in the area of children’s hearing health using interactive tele-education. Methods: Interrupted time series with non-random control group pre-test/ post-test. A cohort of 41 nurses, with no previous formal training in hearing health. A “Children’s Hearing Health” Cybertutor was employed. The effectiveness of the nursing training was verified by comparing pre- versus post-training performance and by analyzing responses to an evaluation questionnaire. Results: Following training, the performance was significantly better in all domains assessed and in the total score. The evaluation questionnaire demonstrated that the Cybertutor was well accepted and the performance revealed in the pre-training phase demonstrated the need for children´s hearing health training. Conclusion: The effectiveness of the nursing training program in the area of Children’s Hearing Health using interactive tele-education could be proven, since there was an improvement in performance in all domains evaluated.

RESUMEN Objetivo: verificar la eficacia de un tutor electrónico - cybertutor en la formación de enfermeros en el área de salud auditiva infantil. Métodos: series temporales interrumpidas con grupo control pretest/posttest no aleatorio. Participaron 41 enfermeros, que fueron capacitados a través de un Cybertutor denomidado "Salud auditiva infantil". La eficacia de la capacitación se verificó comparando el desempeño de los enfermeros en los cuestionarios pre y post capacitación, y la evaluación del Cybertutor se investigó a través de un formulario con preguntas cerradas y abiertas. Resultados: El desempeño en el cuestionario precapacitación demostró la necesidad de capacitación en salud auditiva infantil. Hubo una diferencia en el desempeño después del entrenamiento en todos los dominios evaluados y en el puntaje total. Conclusión: La efectividad del cybertutor en la capacitación de enfermeras en el área de Salud Auditiva Infantil podría demostrarse, ya que hubo una mejora en el rendimiento en todos los dominios evaluados.

RESUMO Objetivo: verificar a eficácia de um tutor eletrônico - cybertutor na capacitação de enfermeiros na área de saúde auditiva infantil. Métodos: séries temporais interrompidas com grupo controle pré-teste/pós-teste não randomizado. Participaram 41 enfermeiros que foram capacitados por meio de um Cybertutor denominado “Saúde Auditiva Infantil”. A eficácia da capacitação foi verificada a partir da comparação do desempenho dos enfermeiros, nos questionários pré e pós-capacitação, e a avaliação do Cybertutor foi investigada por meio de um formulário com perguntas fechadas e abertas. Resultados: O desempenho no questionário pré-capacitação demonstrou a necessidade da capacitação em saúde auditiva infantil. Houve diferença no desempenho após a capacitação em todos os domínios avaliados e no escore total. Conclusão: A eficácia do cybertutor na capacitação de enfermeiros na área de Saúde Auditiva Infantil pôde ser comprovada, uma vez que houve melhora no desempenho em todos os domínios avaliados.

RESUMO Objetivo: verificar a eficácia de um tutor eletrônico - cybertutor na capacitação de enfermeiros na área de saúde auditiva infantil. Métodos: séries temporais interrompidas com grupo controle pré-teste/pós-teste não randomizado. Participaram 41 enfermeiros que foram capacitados por meio de um Cybertutor denominado “Saúde Auditiva Infantil”. A eficácia da capacitação foi verificada a partir da comparação do desempenho dos enfermeiros, nos questionários pré e pós-capacitação, e a avaliação do Cybertutor foi investigada por meio de um formulário com perguntas fechadas e abertas. Resultados: O desempenho no questionário pré-capacitação demonstrou a necessidade da capacitação em saúde auditiva infantil. Houve diferença no desempenho após a capacitação em todos os domínios avaliados e no escore total. Conclusão: A eficácia do cybertutor na capacitação de enfermeiros na área de Saúde Auditiva Infantil pôde ser comprovada, uma vez que houve melhora no desempenho em todos os domínios avaliados.

ABSTRACT Objective: To verify the effectiveness of a nursing training program in the area of children’s hearing health using interactive tele-education. Methods: Interrupted time series with non-random control group pre-test/ post-test. A cohort of 41 nurses, with no previous formal training in hearing health. A “Children’s Hearing Health” Cybertutor was employed. The effectiveness of the nursing training was verified by comparing pre- versus post-training performance and by analyzing responses to an evaluation questionnaire. Results: Following training, the performance was significantly better in all domains assessed and in the total score. The evaluation questionnaire demonstrated that the Cybertutor was well accepted and the performance revealed in the pre-training phase demonstrated the need for children´s hearing health training. Conclusion: The effectiveness of the nursing training program in the area of Children’s Hearing Health using interactive tele-education could be proven, since there was an improvement in performance in all domains evaluated.

RESUMEN Objetivo: verificar la eficacia de un tutor electrónico - cybertutor en la formación de enfermeros en el área de salud auditiva infantil. Métodos: series temporales interrumpidas con grupo control pretest/posttest no aleatorio. Participaron 41 enfermeros, que fueron capacitados a través de un Cybertutor denomidado "Salud auditiva infantil". La eficacia de la capacitación se verificó comparando el desempeño de los enfermeros en los cuestionarios pre y post capacitación, y la evaluación del Cybertutor se investigó a través de un formulario con preguntas cerradas y abiertas. Resultados: El desempeño en el cuestionario precapacitación demostró la necesidad de capacitación en salud auditiva infantil. Hubo una diferencia en el desempeño después del entrenamiento en todos los dominios evaluados y en el puntaje total. Conclusión: La efectividad del cybertutor en la capacitación de enfermeras en el área de Salud Auditiva Infantil podría demostrarse, ya que hubo una mejora en el rendimiento en todos los dominios evaluados.

Abstract Proanthocyanidin has been shown to be efficient in inhibiting matrix metalloproteinases. Objective The aim of this in situ study was to evaluate the protective effect of Proanthocyanidin-based mouthrinses either with naturally acidic or with a neutral pH applied on dentin subjected to erosion. Methodology Eight volunteers wore one palatal device in two phases (7 days washout) with 16 samples per group (n=8). The groups under study were: First Phase/ G1 – 10% proanthocyanidin mouthrinse (pH 7.0, Experimental group 1 – Purified Grape Seeds Oligomeric Proanthocyanidins), G2 – 10% proanthocyanidin mouthrinse (pH 3.0, Experimental group 2 – Purified Grape Seeds Oligomeric Proanthocyanidins). Second Phase/ G3 – 0.12% chlorhexidine mouthrinse (pH 7.0, Positive control group), G4 – no previous treatment (Negative control group). Each device was subjected to 3 erosive cycles (5 minutes) per day for 5 days. Treatments with different mouthrinses were applied once after the second erosive challenge (5 minutes). Profilometry was used to quantify dentin loss (µm). Results Data were analyzed by repeated measures of ANOVA followed by Fisher’s test (p<0.05). G1 (1.17±0.69) and G3 (1.22±0.25) showed significantly lower wear values with no statistical difference between them. G2 (2.99±1.15) and G4 (2.29±1.13) presented higher wear values with no significant differences between them. Conclusion The 10% proanthocyanidin mouthrinse (pH 7.0) could be a good strategy to reduce dentin wear progression.

Abstract Non-inferiority randomized clinical trials are indicated when it is intended to prove that an experimental group is not inferior to a control group by more than a margin of non-inferiority. However, this type of study differs from traditional randomized clinical trials (superiority studies) because they have particularities that impact on the formulation of hypothesis to be tested, experimental design (non-inferiority margin determination, adapted sample size calculation, sensitivity of the study and data final analysis) and also on the presentation of data when writing the manuscript. Therefore, this article aims to present and discuss the particularities of non-inferiority clinical studies, since these requirements are fundamental to guarantee the validity of the conclusions of this type of study.

Abstract The standardization of in situ protocols for dental erosion is important to enable comparison between studies. Objective: Thus, the objectives of this study were to evaluate the influence of the location of in situ intraoral appliance (mandibular X palatal) on the extent of enamel loss induced by erosive challenges and to evaluate the comfort of the appliances. Material and Methods: One hundred and sixty bovine enamel blocks were selected according to their initial surface hardness and randomly divided into two groups: GI - palatal appliance and GII - mandibular appliance. Twenty volunteers wore simultaneously one palatal appliance (containing 4 enamel blocks) and two mandibular appliances (each one containing 2 enamel blocks). Four times per day during 5 days, the volunteers immersed their appliances in 0.01 M hydrochloric acid for 2 minutes, washed and reinserted them into the oral cavity for 2 hours until the next erosive challenge. After the end of the in situ phase, the volunteers answered a questionnaire regarding the comfort of the appliances. The loss of tissue in the enamel blocks was determined profilometrically. Data were statistically analyzed by paired t-test, Chi-square and Fisher's Exact Test (p<0.05). Results: The enamel blocks allocated in palatal appliances (GI) presented significantly higher erosive wear when compared to the blocks fixed in mandibular appliances (GII). The volunteers reported more comfort when using the palatal appliance. Conclusions: Therefore, the palatal appliance is more comfortable and resulted in higher enamel loss compared to the mandibular one.

Abstract Due to the large number of individuals with Unilateral Hearing Loss (UHL) and the recommendation to use hearing assistive devices, studies are required to define possibilities of intervention for this population. Objective: To evaluate the performance of the Remote Microphone System (RMS) in children with UHL. Methodology: Prospective clinical study with a convenience sample. Eleven children (mean age of 9.2 years) with severe and profound sensorineural UHL, hearing aid users and enrolled in regular schools participated in the study. They were evaluated using the Hearing in Noise Test (HINT), the Classroom Participation Questionnaire (CPQ), and the Sustained Auditory Attention Ability Test (SAAAT) with RMS. Results: HINT results were analyzed using variance to three criteria of repeated measures, which revealed differences between intervention, position, and time factors and significant interaction between these three factors. The comparative analysis of the results from CPQ showed significant differences in the statistical t-test (p=<0.001) for all subscales. The analysis of variance at two repeated measures criteria used in the study of SAAAT revealed a difference between intervention and time, and both interacted significantly. Conclusion: The RMS associated with a hearing aid was effective for individuals with UHL.

Abstract Objective: To evaluate in situ the effect of toothpastes containing casein phosphopeptide - amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide-amorphous calcium phosphate associated to fluoride (CPP-ACPF) on initial erosion prevention. Material and Methods: Bovine enamel blocks (n = 192) were randomly assigned into 4 phases according to the baseline surface hardness: GI: CPP-ACP Paste (MI Paste™), GII: CPP-ACPF Paste (MI Paste Plus™), GIII: Fluoridated paste and GIV: Placebo Paste. In each of the 4 crossover phases, twelve volunteers wore intraoral palatal appliances containing 4 enamel blocks for 2 hours, then the tested treatments were applied intraorally (3 min) and the appliance was maintained in the mouth for another 3 hours. After, the appliances were removed and immersed in hydrochloric acid (0.01 M, pH 2.3) for 30 seconds to promote erosive demineralization. The final surface hardness was evaluated and percentage of surface hardness loss was calculated. The data were analyzed by ANOVA and Tukey’s test (α = 5%). Results: The application of CPP-ACP paste, independent of fluoride content, resulted in significant lower enamel hardness loss (GI: 9.26% ±3.48 and GII: 9.14% ±1.73) compared to NaF (GIII: 15.5% ± 3.94) and placebo (GIV: 16.7% ± 4.07) pastes, which did not show difference between them. Conclusion: The CPP-ACP pastes were able to reduce initial erosive demineralization in relation to fluoride and placebo pastes. Nevertheless the formulation of CPP-ACP with fluoride did not provide an additional benefit.

RESUMO Objetivo Revisar sistematicamente a literatura e analisar a efetividade do biofeedback eletromiográfico de superfície na reabilitação de adultos com disfonia comportamental. Estratégia de pesquisa Dois autores realizaram uma busca independente nas bases de dados: Clinical Trials , Cochrane Library, Embase, LILACS, PUBMED e Web of Science. Elaborou-se uma estratégia de busca específica para cada base. Critérios de seleção Foram incluídos estudos que analisaram a efetividade do biofeedback eletromiográfico de superfície comparado com outras intervenções de terapia vocal direta em adultos com disfonia comportamental. Não houve restrição de idioma e data de publicação. Análise de dados Análise do risco de viés, heterogeneidade, dados quantitativos e qualitativos, sensibilidade, subgrupos e viés de publicação. Resultados foram identificados 51 estudos, sendo que apenas dois estudos coorte prospectivos foram analisados. Os estudos apresentaram 100% de risco incerto de viés de seleção, performance e detecção. Houve alta heterogeneidade clínica. A análise descritiva mostrou redução da atividade elétrica muscular e melhora da autoavaliação vocal com o uso do biofeedback eletromiográfico, porém, não foi possível calcular o tamanho do efeito das intervenções. O presente estudo apresentou limitações por não conseguir apresentar um consenso para a maioria dos dados analisados. Conclusão A literatura disponível não permite gerar uma evidência conclusiva acerca da efetividade do biofeedback eletromiográfico comparado a outras intervenções diretas na reabilitação de sujeitos adultos com disfonia comportamental.

ABSTRACT Purpose To review systematically the literature and to analyze the effectiveness of surface electromyographic biofeedback in the rehabilitation of adults with behavioral dysphonia. Research strategies Two authors performed an independent search in the following databases: Clinical Trials, Cochrane Library, Embase, LILACS, PubMed, and Web of Science. A specific search strategy was developed for each database. Selection criteria The review included studies that examined the effectiveness of surface electromyographic biofeedback compared to other direct vocal therapy intervention in adults with behavioral dysphonia. There were no restrictions in regard to language or date of publication. Data analysis Analysis of the risk of bias, heterogeneity, quantitative and qualitative data, sensitivity, subgroups, and publication bias. Results 51 studies were identified, but only two cohort studies remained as prospects for analysis. The studies showed 100% uncertain risk of selection, performance, and detection bias. There was a high degree of clinical heterogeneity. The descriptive analysis showed a reduction in muscle electrical activity and improvement in vocal self-assessment using electromyographic biofeedback; however, it was not possible to calculate the effect size of the interventions. The present study was limited by the fact that it was unable to show a consensus for the majority of data analyzed. Conclusion The available literature does not support a conclusive finding about the effectiveness of surface electromyographic biofeedback compared to other direct interventions used in the rehabilitation of adults with behavioral dysphonia. The studies analyzed vary widely in their clinical procedures and methodology, making it impossible to determine the procedure's effectiveness.

Abstract Objective The prevalence of dental erosion has been recently increasing, requiring new preventive and therapeutic approaches. Vegetable oils have been studied in preventive dentistry because they come from a natural, edible, low-cost, and worldwide accessible source. This study aimed to evaluate the protective effect of different vegetable oils, applied in two concentrations, on initial enamel erosion. Material and Methods Initially, the acquired pellicle was formed in situ for 2 hours. Subsequently, the enamel blocks were treated in vitro according to the study group (n=12/per group): GP5 and GP100 – 5% and pure palm oil, respectively; GC5 and GC100 – 5% and pure coconut oil; GSa5 and GSa100 – 5% and pure safflower oil; GSu5 and GSu100 – 5% and pure sunflower oil; GO5 and GO100 – 5% and pure olive oil; CON− – Deionized Water (negative control) and CON+ – Commercial Mouthwash (Elmex® Erosion Protection Dental Rinse, GABA/positive control). Then, the enamel blocks were immersed in artificial saliva for 2 minutes and subjected to short-term acid exposure in 0.5% citric acid, pH 2.4, for 30 seconds, to promote enamel surface softening. The response variable was the percentage of surface hardness loss [((SHi - SHf) / SHf )×100]. Data were analyzed by one-way ANOVA and Tukey’s test (p<0.05). Results Enamel blocks of GP100 presented similar hardness loss to GSu100 (p>0.05) and less than the other groups (p<0.05). There was no difference between GP5, GC5, GC100, GSa5, GSu100, GSa100, GSu5, GO5, GO100, CON− and CON+. Conclusion Palm oil seems to be a promising alternative for preventing enamel erosion. However, further studies are necessary to evaluate a long-term erosive cycling.