Evaluation of the protective potential of CaneCPI-5, with or without fluoride, in preventing demineralization and in remineralizing artificial carious lesions: an in situ study

• Grant number: 24/09669-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2024
• End date: December 31, 2024
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Marília Afonso Rabelo Buzalaf
• Grantee: Natara Dias Gomes da Silva
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Associated research grant: 19/26070-1 - Modulation of acquired enamel pellicle to control dental mineral loss: unravelling mechanisms to make therapies possible, AP.TEM

Abstract

The project aims to investigate the effects of CaneCPI-5, with or without fluoride, on the prevention of enamel demineralization and on the remineralization of artificial enamel lesions in situ. Initially, bovine enamel samples (4 mm x 4 mm, n=240) will be polished and subjected to initial surface microhardness analysis (5 Knoop indentations, 25 g, 10s). Half of the samples will remain sound, and the other half will be demineralized using the microcosm biofilm model for 5 days. Twenty healthy volunteers will be recruited to participate in the study. Dental arches will be molded to fabricate intraoral devices, in which 4 bovine enamel samples will be inserted, divided into 2 conditions: 2 pre-demineralized samples will be coupled close to the acrylic resin to prevent biofilm accumulation (to promote remineralization); and 2 samples will be inserted 1.5 mm below the surface of the device, protected with plastic mesh to accumulate biofilm, with exposure to 20% sucrose, 8x/day (to promote demineralization). Volunteers will participate in 3 crossover and double-blind phases: Phase A: 0.05 mg/mL CaneCPI-5 (showed the best result in an in vitro study against dental demineralization and in the modulation of initial bacterial biofilm colonization); Phase B: fluoride solution (NaF, 500 mg/L); Phase C: 0.05 mg/mL CaneCPI-5 + fluoride solution (NaF, 500 mg/L). The solutions will be applied as a mouthwash (10 mL, 2x 1 min per day), with the device positioned in the mouth before the first and after the last cariogenic challenge. During the experiment, volunteers will wear the intraoral devices for specific periods (14 days with a 7-day interval between phases to avoid sample contamination). During the experimental period, the device will remain in the mouth and will be removed only during the 3 daily meals. Volunteers should apply 1 drop of 20% sucrose solution for 5 min to the samples corresponding to this condition. Afterward, the device will be repositioned in the mouth. At the end of the experiment, the demineralization of the samples contained in the devices will be analyzed by three-dimensional transverse microradiography (TMRD-3D), and colony-forming units will be counted to assess the presence of bacteria adhered to the samples, using following media 1) Brain Heart Infusion (BHI, Difco, USA) for total microorganism determination; 2) Mitis Salivarius (MSA) for total streptococci determination, 3) Mitis Salivarius (MSA) with 1% potassium tellurite, supplemented with 15% sucrose and 0.2 U/mL bacitracin for mutans group streptococci determination, and 4) Rogosa for total lactobacilli determination. Data will be checked for normality and homogeneity to select the appropriate statistical test (parametric or non-parametric, p < 0.05).