Radiographic interpretation of changes in the tooth and adjacent bone tissue using the tools of the Moodle virtual environment / Interpretação radiográfica de alterações no órgãodentário e tecido ósseo adjacente utilizando as ferramentas do ambiente virtual Moodle

Virtual learning environments (VLEs) have numerous possibilities for the use of their tools and can assist in the processesof teaching and learning aboutthe radiographic image interpretation. This study aimed to evaluate the use of a virtual learning environment as a support material for students in the discipline of Dental Radiology.This radiographic interpretation was conducted to contribute to the knowledge and training of the changes in the tooth andadjacent bone tissue,visualized in periapical and interproximal radiographs. The scores of the virtual test (via the Moodle platform) and the interpretation test (in the classroom) were used to compare Group Number 1 (students thatperformed the virtual test before the classroom test) and Group Number 2 (students thatperformed the virtual test after the classroom test). It was observed that,in general, the mean score of the interpretation test was higher than the virtual.Also,66% of the students used the platform as the main resourceto follow the discipline, due to the possibility of reviewing the contents andactivities. The virtual learning environment can be considered an important complementary sourcefor teaching radiographic interpretation. The Moodle platform acts as a remarkable tool, with the potential capacity to support the teaching and learning process. For this, mutual collaboration among students, University,and educational institution isnecessarily required for the constant use, maintenance,and updating of the virtual environment (AU).

Os ambientes virtuais de aprendizagem (AVA) possuem inúmeras possibilidades de utilização de suas ferramentas e podem auxiliar nos processos de ensino e aprendizagem sobre a interpretação de imagens radiográficas. Este estudo teve como objetivo avaliar a utilização de um ambiente virtual de aprendizagem como material de apoio para alunos da disciplina de Radiologia Odontológica. Essa interpretação radiográfica foi realizada para contribuir com o conhecimento e treinamento das alterações no órgão dentário e tecido ósseo adjacente, visualizadas em radiografias periapicais e interproximais. As notas da prova virtual (via plataforma Moodle) e da prova de interpretação (em sala de aula) foram utilizadas para comparar o Grupo Número 1 (alunos que realizaram a prova virtual antes da prova presencial) e o Grupo Número 2 (alunos que realizaram a prova virtual, após o teste em sala de aula). Observou-se que, em geral, a média da prova de interpretação foi superior à da prova virtual. Além disso, 66% dos alunos utilizaram a plataforma como principal recurso para acompanhar a disciplina, devido à possibilidade de revisão dos conteúdos e atividades. O ambiente virtual de aprendizagem pode ser considerado uma importante fonte complementar para o ensino da interpretação radiográfica. A plataforma Moodle atua como uma ferramenta notável, com potencial capacidade de apoiar o processo de ensino e aprendizagem. Para isso, é necessária a colaboração mútua entre alunos, Universidade e instituição de ensino para a constante utilização, manutenção e atualização do ambiente virtual (AU).

Correction to: Influence of foraminal enlargement on the healing of periapical lesions in rat molars.

Figures 2 and 3 in the published version of this article contained a mistake. CCP and DCP should have been FEG and NFEG. Correct figures are presented here.

Dentists' knowledge of dental trauma based on the International Association of Dental Traumatology guidelines: A survey in South Brazil.

BACKGROUND/AIM: Dental trauma is a public health issue with a high prevalence in children. The aim of this study was to evaluate the level of knowledge of dentists in Rio Grande do Sul, Brazil, of the management of traumatic dental injuries, using the International Association of Dental Traumatology (IADT) Guidelines as a reference. MATERIALS AND METHODS: An electronic questionnaire investigating personal and professional characteristics and 12 questions about dento-alveolar trauma, was sent to all registered dentists of the Regional Council of Dentistry of Rio Grande do Sul (n=14 753). The respondents were grouped according to the sociodemographic and professional profiles and the data were evaluated by the Student-T test or one-way ANOVA, with Tukey's post-hoc, with α = 5%. RESULTS: A total of 1414 dentists responded to the survey (9.59% response rate). The overall mean self-reported knowledge of dental trauma was 5.87 ± 1.57, of a maximum possible score of 12. Some factors associated with a higher knowledge of the IADT guidelines were: female gender, previous clinical experience, years from qualification, self-reported knowledge, and academic postgraduate degree. Dentists who are specialized in endodontics (6.58 ± 1.63) and pediatric dentistry (6.05 ± 1.44) achieved higher levels of knowledge on dental trauma. Analysis of the characteristics (gender, location, and proportion of specialists) of the respondents confirmed that they were representative of the target population. CONCLUSION: The overall level of knowledge of dentists from Rio Grande do Sul of the IADT guidelines is moderate. These results highlight the need for continuing education on dento-alveolar trauma in this population.

Influence of foraminal enlargement on the healing of periapical lesions in rat molars.

OBJECTIVES: The aim of this study was to evaluate the influence of foraminal enlargement on the healing of induced apical periodontitis in a rat model. MATERIAL AND METHODS: Periapical lesions were bilaterally induced in mandibular first molars of 24 Wistar rats, through root canals exposure to the oral environment during 3 weeks. Endodontic treatment was performed in the mesial canal of right molars, which were separated into two experimental groups (n = 12/group). The foraminal enlargement group (FEG) received instrumentation in the entire root canal length, including the cemental canal, while in the non-foraminal enlargement group (NFEG), instrumentation was carried out 1 mm short of the apical foramen. Root canals were filled with gutta-percha and AH Plus sealer, in the same visit, 1 mm short of the apical foramen in both experimental groups. Left molars were not treated and served as a baseline control group. The animals were killed after 4 weeks, and their hemi-mandibles were prepared for radiographic and histological analysis. Data were analyzed by Student's t test and ANOVA. RESULTS: Only FEG presented lower areas of periapical radiolucency compared to the control (p < .05). Both FEG and NFEG allowed decreased inflammation intensity (p < .0001 and p < .01) and higher scores of cementum neoformation when compared to non-treated samples (p < .0001). FEG was more effective than NFEG in promoting biological seal, i.e., apical closure with cementum (p < .01). FEG, but not NFEG, showed lower scores of root resorption than the control. CONCLUSIONS: Foraminal enlargement during root canal preparation improved periapical healing in rat molars. CLINICAL SIGNIFICANCE: Foraminal enlargement has been suggested to improve disinfection at the apical portion of root canals. This procedure may favor the healing of chronic periapical lesions.

Apical transportation in simulated root canals prepared using HyFlex CM, WaveOne Gold and manual technique / Avaliação do transporte apical em canais simulados preparados com instrumentação manual e com movimentos rotatório contínuo e reciprocante

Objective: To assess the apical transportation in simulated root canals with different curvature angles prepared using manual instrumentation and rotary and reciprocating motions. Methods: Sixty simulated root canals were prepared using manual instrumentation (Flexofile K-file) (MT), continuous rotation (HyFlex CM) (HF), and reciprocating motion (WaveOne Gold) (WG). A trained operator prepared the canals, and the apical enlargement was standardized up to a #25 file in all systems tested. Two different curvature angles of the simulated root canals were tested: 70° and 50°. Overlapping photographs of the simulated root canals, before and after root canal preparation, were used to measure the apical transportation (mm), using the ImageJ software. Descriptive statistics (mean and standard deviation) were analyzed and the groups were compared with two-way ANOVA followed by Tukey's post-hoc, with α=5%. Results: There was a statistically significant interaction between the effects of group and angle in the apical transportation (F = 3.740; p = 0.031). Simple main effects analysis showed that HyFlex CM produced a significantly lower apical transportation when compared to WaveOne Gold (p = 0.02) and the manual technique (p < 0.01), regardless of the angle. However, there were no differences between WaveOne Gold and manual technique in canals with the 70° angle (p>0.05). The group with the highest mean apical transportation was the MT, with 0.0917 mm, followed by WG and HF, with 0.0633 and 0.0325, respectively. Conclusion: Simulated root canals prepared with rotary motion (HyFlex CM) showed the lowest apical transportation, followed by the reciprocating motion (WaveOne Gold). The manual technique showed the most unfavorable results, with the highest apical transportation.(AU)

Objetivo: avaliar o transporte apical em canais radiculares simulados com diferentes ângulos de curvatura preparados por meio de instrumentação manual e dos movimentos rotativo e reciprocante. Métodos: sessenta canais simulados foram preparados usando instrumentação manual (Flexofile K- -file) (MT), rotação contínua (HyFlex CM) (HF) e movimento reciprocante (WaveOne Gold) (WG). O preparo do canal radicular foi realizado por um operador treinado, e o alargamento apical foi padronizado até o instrumento #25 em todos os sistemas testados. Dois diferentes ângulos de curvatura dos canais simulados foram testados: 70° e 50°. Fotografias sobrepostas dos canais simulados, antes e após o preparo do canal radicular, foram utilizadas para medir o transporte apical (mm), utilizando o software ImageJ. Estatísticas descritivas (média e desvio padrão) foram analisadas e as comparações entre os grupos foram realizadas através de ANOVA de duas vias, seguido por post-hoc de Tukey, com α=5%. Resultados: houve interação estatisticamente significativa entre os efeitos do grupo e do ângulo no transporte apical (F = 3,740; p = 0,031). A análise simples dos efeitos principais mostrou que o sistema Hy- Flex CM produziu um transporte apical significativamente menor quando comparado ao sistema WaveOne Gold (p = 0,02) e à Técnica Manual (p <0,01), independentemente do ângulo. No entanto, não houve diferenças entre o WaveOne Gold e a Técnica Manual em canais com ângulo de 70 ° (p> 0,05). O grupo que apresentou maior transporte apical médio foi o MT, com 0,0917 mm, seguido pelo WG e pela HF, com 0,0633 e 0,0325, respectivamente. Conclusão: canais radiculares simulados preparados com movimento rotatório (HyFlex CM) mostraram o menor transporte apical, seguido de movimento reciprocante (WaveOne Gold). A técnica manual revelou os resultados mais desfavoráveis, com maior transporte apical.(AU)

Root canal preparation in 3-rooted maxillary premolars through hand, rotary, and reciprocating techniques: a microcomputed tomography evaluation.

Endodontic management of 3-rooted maxillary premolars is a challenge due to their complex anatomy and narrow root canal walls. This study aimed to evaluate, by microcomputed tomography (µCT), the apical enlargement and centering ability promoted by hand, rotary, and reciprocating instrumentation in 3-rooted maxillary premolars. Eighteen teeth were divided into 3 groups (n = 6) according to the preparation technique: crown-down hand, rotary, and reciprocating instrumentation. Instruments with similar apical diameters were used (25 and 40 mm for buccal and palatal canals, respectively). Centering ability and canal enlargement were evaluated through the comparison of µCT images obtained before and after instrumentation. Distances of 0, 2, 4, and 6 mm from the apical stop were considered. Differences between canal areas before and after instrumentation were calculated. In addition, distances between the original canal center and the prepared canal center at the apical stop were measured in both the mesiodistal and buccopalatal directions. Significant differences in enlargement areas and centering ability among the techniques were determined using 2-way analysis of variance and Tukey post hoc test (P > 0.05). Root canal enlargement was similar for all techniques. Excessive enlargement was observed in only a few specimens, and root perforation did not occur. Some specimens presented untreated canal areas. In mesiobuccal and distobuccal roots, reciprocating instrumentation promoted more centered preparations than hand instrumentation when measured in the mesiodistal direction (P > 0.05). There were no other statistically significant differences. The results established that hand, rotary, and reciprocating techniques presented similar safety margins for instrumentation of the apical third of 3-rooted maxillary premolars. Reciprocating instrumentation presented some advantages over hand preparation regarding centering ability.

Clinically relevant dimensions of 3-rooted maxillary premolars obtained via high-resolution computed tomography.

INTRODUCTION: This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen. METHODS: Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD). RESULTS: Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817-1.670 mm) compared with palatal roots (1.361-2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric. CONCLUSIONS: Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation.