Effect of Dental Course Cycle on Anatomical Knowledge and Dental Carving Ability of Dental Students.

This study assessed the effect of the course cycle on theoretical knowledge of dental morphology and the dental carving ability of dental students. Thirty-two dental students from the third semester (initial cycle) and 30 students from the eighth and tenth semesters of the dental course (end cycle) had their theoretical knowledge on dental morphology assessed using a questionnaire with ten closed questions. Their dental carving ability was also assessed using wax carvings in macro models of plaster (for the third [S3] and eight [S8] semesters) and natural-sized artificial teeth (for the tenth [S10] semester). The teeth chosen for the dental carving activity were #16 and #47. The scores were statistically analyzed using the t-test, Kruskal-Wallis test, and Mann-Whitney test (α = 0.05). Students from the initial cycle presented better theoretical knowledge than the other groups did (P < 0.007). No significant differences in carving score were found between the initial and end cycles (P > 0.05), although S10 students obtained a higher score for teeth #16 and #47 (P < 0.05). Natural-sized artificial teeth received a higher evaluation score in dental carvings than the macro models (P < 0.001). Within the limits of this study, it was possible to conclude that students from the initial cycle (S3) presented higher theoretical knowledge, whereas no difference in carving ability was observed between the initial and end cycles. The tenth semester (S10) students performed dental carvings with better quality. Furthermore, carvings in natural-sized artificial teeth presented better quality compared with the macro models.

Educational Interventions to Improve Dental Anatomy Carving Ability of Dental Students: A Systematic Review.

This systematic review aimed to identify the level of impact of educational strategies for teaching tooth carving on the carving ability of undergraduate dental students. The PubMed-NCBI, Cochrane-CENTRAL, LILACS, Ibecs, BBO, Web of Science, and Scopus databases were searched in May 2019, for randomized controlled trials (RCTs) and two-arm non-randomized studies of interventions (NRSI) addressing educational interventions toward the dental carving of undergraduate students. Studies from the year 2000 until the search date, written in English, Portuguese, and Spanish were included. Study screening and data extraction were performed in duplicate and blinded. The data were presented narratively, considering the dental carving ability of students the primary outcome. The risk of bias was assessed using the RoB tool 2.0 and ROBINS-I, and the level of evidence was determined with GRADE. Of 3,574 studies, 6 were included, with 3 RCTs and 3 NRSIs. Very low level of evidence was provided from the NRSIs that flipped classroom (1 study; n = 140) and a student-driven revised module (1 study; n = 264) improved the carving ability of students. Additionally, there was moderate evidence of online complementary material (1 RCT; n = 30) and reinforcement class improving the carving ability of students (1 RCT; n = 29). The replacement of traditional classes by an instructional DVD (1 RCT; n = 73) and assessment of carving projects through digital systems (1 NRSI; n = 79) did not enhance the carving ability of students. Study design, risk of bias, and imprecision downgraded the level of evidence. There was a very low to moderate evidence on the effectiveness of student-driven educational approaches and complementary classes of dental anatomy in improving the dental carving ability of students.

How do dental faculty members relate to Evidence-Based Dentistry?

Building the rationale to critically appraise scientific evidence on the best approach for each patient requires incorporating the Evidence-Based Dentistry (EBD) model, preferably into undergraduate dental courses. This approach would favor the diffusion of EBD culture amongst dental professionals. Therefore, this study aimed to characterize the relationship of dental faculty members with the EBD model. The study was conducted in 2018 with all 23 dental faculty members (100% response rate) of a community university. They responded the Evidence-Based Practice Questionnaire (EBPQ) and a set of supporting questions involving sociodemographics, search for information, proficiency of foreign languages, and perceived need for knowledge on issues related to EBD. The data were analyzed by descriptive statistics. A total of 73.9% of faculty members claimed having been prepared to search for scientific evidence and 69.5% are aware of connected computer systems for research. Scientific journals, the internet, courses, and colleague opinions were the main sources of information. Reading and comprehension of foreign languages was limited to 30%. The practice and attitudes towards EBD by dental faculty members were positive, with the lowest mean value of 4.85. Knowledge and skills related to EBD had lower mean values, which coincided with a relatively high perceived need for knowledge on EBD. Dental faculty members present a positive attitude towards the EBD model, have been trained to search for scientific information and acknowledge the existence of institutional structure for applying and teaching EBD. On the other hand, knowledge and skills associated with EBD may require improvement (AU).

A construção do raciocínio para avaliar criticamente a evidência científica sobre a melhor abordagem para cada paciente requer a incorporação do modelo de Odontologia Baseada em Evidências (OBE), preferencialmente ainda no ensino de graduação. Essa abordagem favorece a difusão da cultura da OBE entre os profissionais de Odontologia. Assim, este estudo teve como objetivo caracterizar a relação de docentes de um curso de Odontologia com o modelo OBE. O estudo foi conduzido em 2018 com todos os 23 professores de uma universidade comunitária. Eles responderam o EvidenceBased Practice Questionnaire (EBPQ) e algumas perguntas complementares envolvendo fatores sociodemográficos, busca por informação, proficiência em idioma estrangeiro e necessidade percebida de conhecimento sobre aspectos relacionados à OBE. Os dados foram analisados descritivamente. Aproximadamente 74% dos professores afirmaram ter sido preparados para pesquisar por evidência científica e 69,5% reconheceram a existência de computador conectado para essa finalidade. Periódicos, internet, cursos e opinião de colegas foram as principais fontes de informação. Leitura e compreensão de idiomas estrangeiros foram limitadas a 30%. A prática e as atitudes voltadas à OBE pelos professores foram positivas, com um valor mínimo de 4,85. O conhecimento e as habilidades relacionadas à OBE tiveram valores mais baixos, que coincidiram com alta necessidade percebida de informação sobre OBE. Os professores apresentaram uma atitude positiva com relação ao modelo da OBE, foram treinados para buscar informação científica e reconhecem a estrutura institucional para fazê-lo e ensiná-lo. Por outro lado, o conhecimento e as habilidades relacionadas à OBE requerem melhorias (AU).

Effect of acidic solutions on the surface degradation of a micro-hybrid composite resin.

Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena.

Effect of Acidic Solutions on the Surface Degradation of a Micro-Hybrid Composite Resin

Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena.

Resinas compostas podem sofrer desgaste pela ação de substâncias químicas (saliva, álcool, ácidos bacterianos) presentes no ambiente oral, que podem afetar a estrutura e as propriedades superficiais do material. Assim, este estudo avaliou o efeito de substâncias ácidas nas propriedades superficiais de uma resina composta micro-híbrida (Filtek Z-250). Oitenta espécimes foram preparados e mensurados quanto à dureza e rugosidade superficial iniciais (KMN0 e Ra0, respectivamente). Os espécimes foram submetidos a testes de sorção (SO) e solubilidade (SL) de acordo com a ISO 4049:2009, porém usando diferentes soluções de armazenamento: água deionizada, solução etanol/água 75/25% em volume, ácido lático, ácido propiônico e ácido acético. Os ácidos foram utilizados em duas concentrações: PA e 0,02 N. O pH foi mensurado para todas as soluções e a dureza e rugosidade superficial finais (KMN1 e Ra1, respectivamente) foram mensuradas. Os dados foram analisados com testes t-pareado e ANOVA a um fator, e teste de Tukey (p<0,05). Todas as soluções reduziram a dureza e aumentaram os valores de Ra, exceto para os espécimes armazenados em água e ácido lático 0,02 N, que mantiveram a dureza. Todas as soluções produziram fenômenos de SO e SL similares, exceto o ácido lático 0,02 N, que causou menor solubilidade do que as outras soluções. Etanol mostrou o maior pH (6,6) e o ácido lático 0,02 N o menor deles (2,5). As soluções afetaram negativamente as propriedades superficiais da resina composta; além disso, um pH ácido não parece ser um fator significante para intensificar os fenômenos de degradação superficial.

Resistência à fratura de dentes restaurados com resina composta direta / Fracture resistance of teeth restored with direct composite restorations

O objetivo do presente estudo foi avaliar a resistência à fratura de dentes restaurados com resina composta na técnica direta. Vinte e seis terceiros molares humanos hígidos foram selecionados e aleatoriamente divididos em 3 grupos: G1: grupo controle (n=5) - sem preparo cavitário; G2: (n=5) - com preparos cavitários MOD, porém não restaurados; G3: resina composta (n=8) - com preparos MOD restaurados usando o sistema adesivo Single Bond (3M/ESPE) e resina composta P-60 (3M/ESPE). As cavidades foram preparadas com 1/3 da distância intercuspídea, usando uma máquina de fresagem (Galloni). Os materiais foram utilizados de acordo com as instruções do fabricante. Os espécimes foram submetidos à carga compressiva com uma máquina de ensaio universal (Kratos), a uma velocidade de 0,5 cm/m. As médias foram calculadas em MPa, de acordo com a área de superfície de cada dente: G1=48.46 (+ ou - 21.42), G2=20.37 (+ ou - 4.09), G3=40.21 (+ ou - 11.91). Os dados foram submetidos à análise estatística usando ANOVA e teste de Tukey Post-Hoc. G2 apresentou valores de resistência significativamente menores que G1 (p<0.05), enquanto G3 e G1 apresentaram valores similares. Concluiu-se, pela metodologia empregada, que o preparo cavitário reduziu a resistência à fratura dos dentes e que as restaurações de resina composta recuperaram a resistência perdida, aproximando-se do grupo controle