Efficiency of cavitary varnishes containing experimental bioglass particles in the occlusion of dentinal tubules.

This research aims to evaluate the efficiency of cavitary varnishes containing experimental bioglasses in the occlusion of dentinal tubules. One hundred and sixty-eight cervical buccal dentin samples were obtained from bovine teeth. Samples were randomized into the following groups: I. Distilled Water (DW); II. Cavity Varnish (CV); III. Colgate® Sensitive Pro-Relief™ (CS); IV. 45S5 Bioglass (45S5); V. KSr Bioglass strontium potassium (KSr); VI. P Bioglass phosphorus (P); and VII. PSi Bioglass phosphorus silica (PSi). The treatments were applied to the surfaces of the samples, which were then subjected to simulated brushing. The samples were analyzed for a) characterization of bioactive glasses; b) surface roughness; c) descriptive analysis of the dentin surface; d) total versus occluded number of dentinal tubules; e) diameter of the dentinal tubules; f) chemical composition of the dentin surfaces, and g) dentin permeability. All groups treated with biomaterials without the brushing challenge showed an increase in roughness and (total or partial) occlusion of the dentinal tubules. The PSi group had the best values for occlusion, while the KSr group had the highest calcium and phosphorus concentrations. After the brushing challenge the roughness was controlled by the presence of biomaterials; 45S5, KSr, and PSi showed occlusion of the dentin tubules. All bioactive glasses showed reduced tooth permeability compared to distilled water. The PSi group had the smallest tubule diameter and highest phosphorus concentration. KSr and PSi bioglasses are promising materials for dentin occlusion and remineralization and are promising new biomaterials for the treatment of dentin hypersensitivity.

Prevalence of dentin hypersensitivity after orthodontic treatment: A cross-sectional study.

INTRODUCTION: The prevalence of cervical dentin hypersensitivity in patients after corrective orthodontic treatment has been poorly studied, although such hypersensitivity is very common. This study aimed to assess the prevalence of dentin hypersensitivity in patients who received corrective orthodontic treatment, the impact of general oral problems on quality of life, and the impact of hypersensitivity on the quality of life of this population. METHODS: This observational, cross-sectional study evaluated 232 patients who finished orthodontic treatment between 2000 and 2020 for self-reported hypersensitivity and clinically diagnosed hypersensitivity. The following tests were used: tactile, evaporative (bellows), evaporative (triple syringe), and thermal. The patients were also evaluated regarding their quality of life using questionnaires (Oral Health Impact Profile-14 and Dentine Hypersensitivity Experience Questionnaire). We evaluated data with nonparametric statistics. RESULTS: The prevalence of hypersensitivity was higher in women and in those aged <30 years; the most affected teeth were the mandibular incisors and premolars; different diagnostic tests for hypersensitivity may indicate different prevalence values; patients with hypersensitivity had a lower quality of life in most of the domains of both of the tests that were used. CONCLUSIONS: The prevalence of hypersensitivity among patients after orthodontic treatment may be higher than in the general population. Further investigation is needed to indicate the possible factors associated with orthodontic tooth movement.

Effect of bioactive glasses used as dentin desensitizers on the dentin-pulp complex in rats.

Bioactive glasses have been recommended for the occlusion of dentinal tubules in treating cervical dentin hypersensitivity. This study evaluates an in vivo model of dentin exposure, and tests the efficacy of bioglass treatments. Thirty male Wistar rats received gingival recession surgery on the upper left first molar. The treatments were applied over the surface of the exposed dentin every 4 days for 28 days. The groups were as follows: Naive; Gingival recession; Cavity varnish; Biosilicate®; Strontium bioglass; and Potassium bioglass. Changes in the dentin-pulp complex, and the presence of substance P, were evaluated through hematoxylin-eosin and immunohistochemical staining. The groups had similar results. Teeth with exposed dentinal tubules in rats showed a typical pattern in the dentin-pulp complex and immunotracing for substance P. The materials did not cause pulp damage. The effects of gingival recession and open dentinal tubules on pulp tissue require further clarification.

Learning styles preferences and e-learning experience of undergraduate dental students / Preferências nos estilos de aprendizagem e experiência com e-learning de estudantes de graduação em Odontologia

Introduction: Education in the health sciences has been undergoing profound changes due to the incorporation of information and communication technologies. Students learn through a variety of approaches, according to their learning styles. Blended learning, which combines technology-aided learning (e-learning) with traditional face-to-face teaching methods, has been found to improve learning outcomes. Objective: The aims of the present study were to evaluate the learning styles of undergraduate dental students and their experience towards the use of e-learning. Material and method: Two electronic questionnaires were sent to 174 students. The learning styles were determined by the Felder & Soloman Index (ILS), which evaluates the following four dimensions of learning: processing information (active-reflexive); perceiving information (sensorial-intuitive); receiving information (visual-verbal); and understanding information (sequential-global). To determine the e-learning experience we used four questions (Likert scale - five-point) which addressed the experience and the use of information and communication technologies. Result: Most students presented a well-balanced style for the active-reflective (60%) and sequential-global (68%) domains. The sensing style (64%) was predominant. A lower percentage presented a global characteristic (9%). We did not find significant differences regarding the age groups (19-21 and 22-33 years) and genders (P>0.05, χ 2). However, in terms of age the difference was significant concerning websites helping in learning (P=0.0363, Mann-Whitney). Conclusion: We conclude that the students do not have the same learning styles and e-learning experience. Methods such as blended learning could provide advantages when teaching undergraduate dental students.

Introdução: A educação em ciências da saúde tem passado por profundas mudanças devido à incorporação de tecnologias de informação e comunicação (TICs). Os estudantes aprendem através de diferentes abordagens, de acordo com o seu estilo de aprendizagem. O ensino híbrido, que combina tecnologia (e-learning) com o ensino face-a-face, tem apresentado bons resultados. Objetivo: Os objetivos deste estudo são avaliar os estilos de aprendizagem de alunos de graduação em Odontologia e a experiência com e-learning. Material e método: Dois questionários eletrônicos foram enviados a 174 estudantes. Os estilos de aprendizagem foram determinados pelo Índice de Felder & Soloman (ILS), que avalia as quatro dimensões do aprendizado: processamento da informação (ativo-reflexivo); percepção da informação (sensorial-intuitivo); recebimento da informação (visual-verbal); e entendimento da informação (sequencial-global). Para determinar a experiência com e-learning foram usadas quatro perguntas (escala Likert de cinco pontos) sobre o uso das TICs. Resultado: A maioria dos estudantes apresentou um estilo equilibrado para ativo-reflexivo (60%) e sequencial-global (68%). O estilo sensitivo (64%) foi predominante. Uma porcentagem mais baixa apresentou características globais (9%). Não foram encontradas diferenças quanto aos grupos de idades (19-21 e 22-33 anos) e aos gêneros (P>0,05, χ2). Contudo, houve diferença entre os grupos de idades considerando a ajuda dos websites no aprendizado (P =0,0363, Mann-Whitney). Conclusão: Os estudantes não têm os mesmos estilos de aprendizado e experiência com e-learning. Métodos alternativos ao ensino convencional, como o ensino híbrido, podem significar vantagens no ensino da graduação em Odontologia.