Investigation on the effect of antimicrobial photodynamic therapy as an adjunct for management of deep caries lesions-study protocol for a randomized, parallel groups, controlled clinical trial.

BACKGROUND: Alternatively to conventional treatments, chemo-mechanical caries removal agents can be used. A modality of treatment that has been increasing in dentistry is antimicrobial photodynamic therapy (aPDT). Bixa orellana is being researched for application in aPDT. This protocol aims to determine the effectiveness of aPDT with Bixa orellana extract in deep caries lesions. METHODS: A total of 160 teeth with deep occlusal dental caries will be selected and divided into 4 groups: G1 - control group (Caries removal with a low-speed drill); G2 - Partial Caries Removal with Papacarie™ (Fórmula e Ação, São Paulo, SP, Brazil); G3 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) (Fórmula e Ação, São Paulo, SP, Brazil); G4 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) with LED (Valo Cordless Ultradent®, South Jordan, UT, USA) (aPDT). After treatment, all the teeth will be restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at immediately, 1 week, and 1, 3, 6, and 12 months. Dentin samples before and after treatment will be analyzed microbiologically. The efficacy of treatments will be assessed with microbiological (colony-forming units, before and after carious tissue removal), radiographic (integrity of the periapical area and eventual changes in the radiolucent zones), and clinical examinations (retention of the restorative material in the cavity and occurrence of secondary caries), as well as with the time required for the procedures and the need for anesthesia during the procedures. In case data distribution is normal, analysis of variance (ANOVA) will be used for both the dependent and independent variables. In case the data distribution is not normal, the Friedman test will be used for the dependent variables. For independent variables, the Kruskal-Wallis test will be used. DISCUSSION: Procedures using aPDT have been developed for the treatment of dental caries, but there are few controlled clinical trials in the literature confirming its efficacy. TRIAL REGISTRATION: This protocol is registered at ClinicalTrials.gov under the number NCT05236205 and it was first posted on 01/21/2022 and last updated on 05/10/2022.

Efeito Biomodificador de Diferentes Agentes de Ligações Cruzadas nas Propriedades Mecânicas do Colágeno Dentinário / Biomodifying Effect of Different Cross-Linking Agents on the Mechanical Properties of Dentin Collagen

Objetivo: avaliar o efeito biomodificador dos agentes de ligações cruzadas nas propriedades mecânicas do colágeno dentinário. Material e Métodos: Trata-se de um estudo laboratorial in vitro, nos quais foram confeccionadas 18 barras de dentina a partir de terceiros molares humanos extraídos e livres de cárie. Os espécimes foram desmineralizados em ácido fosfórico a 10%, por 5 horas, distribuídos aleatoriamente nos grupos distintos e mantidos em suas respectivas soluções de pré-tratamento: água destilada (AD), Proantocianidina a 6,5% (PAC6,5) e Cardanol a 6,5% (CAR6,5) por períodos de 1 hora. Foram realizados os testes de flexão de três pontos para obtenção do módulo de elasticidade (ME) e modificação de massa (MM). Foram submetidos ao teste de Kolmogorov-Smirnoff seguido, do teste de ANOVA à um critério e pós teste de Tukey para a MM, e Dunns para diferença de ME (p<0,05). Resultados: Os valores obtidos no ME mostraram mudanças estatísticas notáveis em todos os grupos testados, quando comparados ao controle negativo (p<0,001), assim como na variação de massa foram encontradas diferenças estatísticas nos valores médios entre os grupos testados (p=0,012). Conclusão: o uso da PAC6,5 irá melhorar as propriedades mecânicas do colágeno

Objective: to evaluate the biomodifying effect of cross-linking agents on the mechanical properties of the teeth. Material and Methods: this is an in vitro laboratory study, in which 18 bars of dentin were made from extracted, caries-free human third molars. The samples were demineralized in 10% phosphoric acid for 5 hours, randomly distributed in different groups and kept in their pre-treatment solutions: distilled water (AD), Proanthocyanidin at 6.5% (PAC6.5) and Cardanol at 6.5% (CAR6.5) for periods of 1 hour. Three-point bending tests were performed to obtain the modulus of elasticity (ME) and mass modification (MM). They were submitted to the Kolmogorov-Smirnoff test followed by the Kruskal-Wallis' test and the Tukey's post-test for mass modification, and Kruskal-Wallis' test after a Dunn's test for difference in the modulus of elasticity(p <0.05). Results: the values selected in the ME show possible statistical changes in all groups tested, when compared to the negative control (p<0.001), as well as the mass variation. Data were shown in the average values between the groups tested (p = 0.012). Conclusion: The use of PAC6.5 will improve the mechanical properties of the collection