3D Digital technology as an alternative educational tool in preclinical dentistry.

INTRODUCTION: The advancement of 3D digital scanners has allowed educators to uphold the quality of education whilst implementing novel methods of assessment. OBJECTIVE: The purpose of this study was to compare two evaluation methods, conventional and digital scanned assessments, on student cavity preparations and students and faculty's perceptions of these assessment methods. METHODS: Predoctoral students performed Class II amalgam and Class III resin composite preparations on simulated teeth for their preclinical competency examinations. Two calibrated faculty evaluated the students' preparations using dental instruments for conventional assessments and 3D scanned images for digital assessments. Faculty scores from both assessment methods were compared and statistically analysed (p < .05). Students also self-assessed their performance using the digital scanned images and filled out a perception survey. RESULTS: There was no statistically significant difference between the conventional (Class II; 73.3 ± 12.2 and Class III; 82.5 ± 8.9) and the digital assessment with scanned images (Class II; 71.3 ± 11.0 and Class III; 82.2 ± 8.2). Faculty scores from both methods have shown a trend of comparability. Most students agreed that digital ideal preparation models were useful (84.2%) and almost all students agreed that digital technology helped them learn operative dentistry (91.1%). In contrast, most students agreed that conventional assessment should be the main self-evaluation system (82.2%) and disagreed that digital assessment is more effective than conventional self-assessment (68.3%). CONCLUSION: Our study demonstrated that 3D digital technology could be an alternative and/or supplementary educational tool to aid in upholding the quality of dental education.

Effect of an experimental chitosan/casein gel on demineralized enamel under a cariogenic challenge.

BACKGROUND: Dental caries is considered one of the most common oral health diseases. OBJECTIVES: The aim of the study was to evaluate the effects of an experimental chitosan/casein gel on enamel demineralization/remineralization in an environment with a high cariogenic challenge. MATERIAL AND METHODS: Thirty-six specimens of bovine enamel (4 mm × 3 mm × 2 mm) were ground flat and polished. Then, the specimens were immersed in acetate buffer for 43 h with half of the surface protected (serving as control) and the other half exposed. All demineralized surfaces were randomly assigned into 3 groups (n = 12 per group) according to the type of treatment (G1 - control, G2 - 1.5% chitosan gel with 1.5% casein, and G3 - 1.5% chitosan gel without casein), and the corresponding treatment was applied once a week for 3 weeks. The specimens were also subjected to pH cycles of demineralization/ remineralization and the treatments were performed 3 times at 7-day intervals for a total of 21 days. Surface images were obtained for the analysis of initial roughness and, after the cariogenic challenge, new images were obtained to evaluate the final roughness, volume loss and wear profile using laser confocal microscopy. After the analyses, the specimens were cut and the depth of demineralization was measured. The data were analyzed using the Kruskal-Wallis analysis of variance (ANOVA) and the Tukey's test. RESULTS: While the chitosan gel with casein showed a similar loss to the control group (p > 0.05), both gels resulted in similar volume loss (p > 0.05). There were no statistical differences regarding the wear profile, surface roughness and depth of demineralization between the groups (p > 0.05). CONCLUSIONS: The chitosan gel reduced volume loss of the demineralized enamel without significantly impacting the surface smoothness.

Impact of Endodontic Kinematics on Stress Distribution During Root Canal Treatment: Analysis of Photoelastic Stress.

INTRODUCTION: Structural defects created by endodontic treatment are the most common cause of major dental failures. This study analyzed levels of stress produced by endodontic instruments during the root canal treatment by photoelastic analysis of stress. METHODS: Twenty-four human premolars were randomly divided into 4 groups (n = 6) according to instrumentation protocol: ProTaper Next (GPT), One Shape (GOS), Wave One Gold (GWO), and TF Adaptive (GTF). The evaluation of the photoelastic model was performed at 4 dental zones: dental-crown region, cervical third of root, middle third of root, and apical third of root. Silicone molds were prepared (2 × 15 mm), and pinjets were used inside the root canals to fixate teeth. Photoelastic resin (2:1 ratio) was poured into the silicone molds to form photoelastic models. A transmission polariscope was used to analyze the positions of interest and recorded with a digital camera. Tardy's method was used to quantify the fringe order (n) and calculate the maximum stress value (τ) at each selected point. Data were analyzed with two-way analysis of variance, Tukey test (P < .05), fringe descriptive analysis. RESULTS: All groups showed a significant increase in the level of stress created during biomechanical preparation of the root canals. In the quantitative analysis, there was no statistically significant difference among the groups (P > .05). In the qualitative analysis, GPT and GTF instruments achieved greater levels of stresses compared with GWO and GOS instruments. At the beginning of instrumentation, stresses were concentrated at the coronary level and the end of instrumentation at the middle and apical root level. CONCLUSIONS: All endodontic systems resulted in accumulation of stress along the dental structure. Stress was found in different concentrations along the tooth and at different levels.

Decision tree protocol for demineralized gingival margin extension in class II composite cavity preparations.

This study proposed the development of a protocol for class-II preparations with demineralized gingival margins for the improvement of the longevity of restorations. Evidence sources such as location/color/surface hardness/width of demineralized gingival margin with enamel/demineralized enamel (DE)/dentin/cementum were reviewed based on methodological studies and systematic reviews. A decision tree protocol was developed with criteria (i) lesion location: demineralized gingival margins in enamel must be removed, but if close to cementoenamel-junction, color should be evaluated. (ii) Color: yellow/brown lesions must be removed, but if white/opaque, then the surface hardness should be evaluated. (iii) Surface hardness: soft/demineralized gingival margin must be removed, but if adequately hard, width should be evaluated. (iv) Width: lesions less than half-enamel thickness and impenetrable by an explorer, remineralization is possible and the lesion does not need to be removed. A decision tree protocol was set up with the current available literature. Further continued investigations will be needed for the appropriate protocol updates.

Study of the chemical interaction between a high-viscosity glass ionomer cement and dentin.

OBJECTIVE: To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed the dynamics of GIC setting mechanism based on the time intervals required for the GIC and the GIC mixed with dentin to achieve stability. MATERIAL AND METHODS: Each constituent of GIC - powder (P) and liquid (L) - and powdered dentin (D), as well as the associations P+L, D+L, and P+L+D in the concentrations of 29%, 50%, 65%, 78%, 82%, and 92% of GIC were analyzed with Fourier transform infrared (FTIR) and Raman spectroscopy. RESULTS: New optical absorption bands and/or Raman bands, which were not present in P, L, or D, were observed in the associations. The concentrations of 29% and 50% of GIC showed higher interaction, revealing that the amount of dentin influences the formation of new optical absorption or scattering bands. FTIR bands showed that the setting time to achieve bond stability was longer for the high-viscosity GIC (38±7 min) than for the sample with 29% of GIC (28±4 min). CONCLUSIONS: The analysis revealed the formation of new compounds or molecular rearrangements resulting from the chemical interactions between GIC and dentin. Moreover, this study provides an effective method to evaluate the dynamics of the setting mechanism of GICs.

Study of the chemical interaction between a high-viscosity glass ionomer cement and dentin

Abstract Objective To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed the dynamics of GIC setting mechanism based on the time intervals required for the GIC and the GIC mixed with dentin to achieve stability. Material and Methods Each constituent of GIC - powder (P) and liquid (L) - and powdered dentin (D), as well as the associations P+L, D+L, and P+L+D in the concentrations of 29%, 50%, 65%, 78%, 82%, and 92% of GIC were analyzed with Fourier transform infrared (FTIR) and Raman spectroscopy. Results New optical absorption bands and/or Raman bands, which were not present in P, L, or D, were observed in the associations. The concentrations of 29% and 50% of GIC showed higher interaction, revealing that the amount of dentin influences the formation of new optical absorption or scattering bands. FTIR bands showed that the setting time to achieve bond stability was longer for the high-viscosity GIC (38±7 min) than for the sample with 29% of GIC (28±4 min). Conclusions The analysis revealed the formation of new compounds or molecular rearrangements resulting from the chemical interactions between GIC and dentin. Moreover, this study provides an effective method to evaluate the dynamics of the setting mechanism of GICs.

Desenvolvendo o paradigma da integralidade no cuidado à saúde no PETSaúde/UEM: relato de experiência: atuação de maneira articulada no cuidado integral à saúde da comunidade / Developing the paradigm of Comprehensiveness in health care in PETSaúde/UEM: experience report: acting in a manner articulated in the integrated community health care

O curso de Odontologia da UEM iniciou sua participação no Projeto PET-Saúde a partir da Portaria Interministerial N.º 3, de 7 de maio de 2009. Atualmente, o programa conta com cinco grupos tutoriais, incluindo seis cursos do Centro de Ciências da Saúde (CCS) e um do Departamento de Psicologia. O objetivo deste trabalho é relatar a experiência do grupo tutorial vinculado à UBS Mandacaru, em Maringá ­ PR, que no ano de 2013 trabalhou com o tema "Fortalecimento da Rede Mãe Paranaense no município de Maringá-PR". A dinâmica de trabalho foi dividida em: Abordagem do tema por meio de oficinas sobre o PETSaúde e a Rede Mãe Paranaense e a realização de palestras e oficinas sobre aleitamento materno. Foi realizada uma pesquisa ajustada à realidade local, além de visitas à UBS e a participação no grupo de apoio às gestantes. A aprendizagem ativa com análise crítica do serviço foi exercida por meio da participação no Conselho Municipal e Local de Saúde. As atividades mostraram que o trabalho individual não supre as necessidades da população, mas sim, um trabalho em equipe. Uma equipe multiprofissional que atue de maneira articulada ao cuidado integral à saúde dos indivíduos. O PET-Saúde possibilita ao aluno aprender a direcionar as ações baseadas na autonomia e corresponsabilidade, bem como adquirir liderança para levar adiante o compromisso com o bem-estar da população (AU).

The course of Dentistry UEM began its participation in Project PET-Saúde from the Ministerial Ordinance No. 3 of May 7, 2009. Today the program has 5 tutorial groups , including 5 courses at the Center for Health Sciences ( CCS ) and 1 Department of Psychology . The aim of this study was to report the experience of the tutorial group linked to UBS Mandacaru in Maringá - PR , who worked with the theme "Strengthening Mother Network Paranaense in Maringá - PR ". Dynamics of work was divided into: Addressing the issue through workshops on PET - Saúde and Mother Rede Paranaense and lectures and workshops on breastfeeding. The survey was adjusted to local realities, prioritizing the teaching-service integration with UBS visits and participation in support group for pregnant women. The active learning through critical analysis of services, through participation in the Municipal Local Health Board, was also performed. This project has shown that individual work does not meet the needs of the population, but rather a team effort. A multidisciplinary team that acts in coordination in comprehensive health care to individual. The PET-Saúde allows the student to learn how to drive actions based on autonomy and responsibility as well as acquire leadership to carry forward the commitment to the welfare of the population (AU).