Efficacy of 30% and 38% Silver Diamine Fluoride in Arresting Caries Lesions After Different Application Times: An in Vitro Study

Abstract Objective: To evaluate the efficacy of silver diamine fluoride (SDF) in arresting dentin caries lesions when applied under different concentrations and times. Material and Methods: Forty-two bovine blocks were selected and fixed in 24-well plates. Each well received a mixed bacterial inoculum added to the culture medium with 5% sucrose. The plates were incubated in microaerophilia (7 days) for caries formation, confirmed by micro-CT (M1). SDF was applied over the carious lesions for different times and concentrations (n=6): SDF 30% - immediate removal, 1 minute and 3 minutes; SDF 38%, - immediate removal, 1 minute and 3 minutes. The group without treatment was the control. Then, the samples were again scanned by micro-CT (M2) and submitted to a second cariogenic challenge for 21 days. Then, a final scan was performed (M3). Results: Mean pH at the culture medium and lesion depth were compared using Kruskal-Wallis and Wilcoxon tests. 38% SDF showed the lowest metabolic activity of the biofilm. All 38% groups and 30% 1 and 3 minutes did not show an increase in mean lesion depth comparing M3 with M1. However, only 30% 3 minutes and 38% 1 and 3 minutes showed a significant reduction of lesion depth. Conclusion: The minimum application time of 30% SDF to arrest dentin caries lesion was 1 minute, while 38% SDF arrested with application and immediate removal.

Root canal segmentation in cone-beam computed tomography: comparison with a micro-CT gold standard

Aim: The purpose of this study was to compare root canal volumes (RCVs) obtained by means of cone beam computed tomography (CBCT) to those obtained by micro-computed tomography (micro-CT) after applying different segmentation algorithms. Methods: Eighteen extracted human teeth with sound root canals were individually scanned in CBCT and micro-CT using specific acquisition parameters. Two different images segmentation strategies were applied to both acquisition methods (a visual and an automatic threshold). From each segmented tooth, the root canal volume was obtained. A paired t-test was used to identify differences between mean values resulted from the experimental groups and the gold standard. In addition, Pearson correlation coefficients and the agreement among the experimental groups with the gold standard were also calculated. The significance level adopted was 5%. Results: No statistical differences between the segmentation methods (visual and automatic) were observed for micro-CT acquired images. However, significant differences for the two segmentation methods tested were seen when CBCT acquired images were compared with the micro-CT automatic segmentation methods used. In general, an overestimation of the values in the visual method were observed while an underestimation was observed with the automatic segmentation algorithm. Conclusion: Cone beam computed tomography images acquired with parameters used in the present study resulted in low agreement with root canal volumes obtained with a micro-CT tomography gold standard method of RCV calculation

Association of parenting style with the behaviour and caries prevalence of preschool children

Objective: This study aimed to associate parenting styles (democratic,authoritarian, and permissive) with the behaviour, and prevalence of caries lesionsamong preschool children submitted to dental care. Methods: At the initialconsultation, preschool children (n = 67), from two to six years of age, wereevaluated for behaviour through the Frankl scale. The parenting styles wereinvestigated through the Parenting Styles and Dimensions Questionnaire - ReducedVersion (PSDQ) and the prevalence of caries lesions through the dmft index.Sociodemographic and economic data were collected. The chi-squared test wasused for association among parenting styles, dmft index, type of behaviour(dichotomised as positive and negative), and the following independent variables:socioeconomic level, single child, school attendance, and educational level of theperson in charge. ANOVA followed by the Tukey test were used to compare themean dmft and parenting styles. Results: The majority of preschoolers presentedpositive behaviour (83.6%), and the dmft mean was 4.76 (± 3.43). Of the total,49.3% were democratic, 44.8% were permissive, and 6% were authoritarian. Therewas no association between parenting styles and all variables investigated (p >0.05). Conclusion: Considering the results, it can be observed that there was noassociation among parenting styles, caries prevalence, and behaviour of thepreschool children in an initial dental consultation.

Objetivo: Objetivou-se associar os estilos parentais (democrático, autoritário epermissivo) com o comportamento e a prevalência de lesões de cárie de pré-escolaressubmetidos ao atendimento odontológico. Métodos: Em consulta inicial, pré-escolares(n = 67), de 2 a 6 anos de idade, foram avaliados quanto ao comportamento, atravésda escala de Frankl. Os estilos parentais de seus responsáveis foram averiguadosatravés do Questionário de Estilos e Dimensões Parentais ­ Versão Reduzida (PSDQ)e a prevalência de lesões de cárie através do índice ceod. Foram coletados dadossociodemográficos e econômicos. Utilizou-se o teste do Qui-quadrado para associaçãoentre os estilos parentais, o índice ceod, tipo de comportamento (dicotomizado empositivo e negativo) e as variáveis independentes: nível socioeconômico, ser filhoúnico, frequentar escola e nível educacional do responsável. ANOVA seguido de Tukeyfoi utilizado para comparar as médias ceod e os estilos parentais. Resultados: Amaioria dos pré-escolares apresentaram comportamento positivo (83,6%) e a médiado ceo-d da população estudada foi 4,76 (± 3,43). Do total dos responsáveis, 49,3%eram democráticos, 44,8% permissivos e 6% autoritários. Não houve associaçãoentre os estilos parentais e todas as variáveis investigadas (p > 0,05). Conclusão:Diante dos resultados, pode-se observar que não houve associação entre os estilosparentais avaliados, prevalência de cárie e comportamento dos pré-escolares emconsulta odontológica inicial.