Evaluation of dentin caries lesions caused by microcosm biofilm - analysis by optical coherence tomography and transverse microradiography: a comparative study

• Grant number: 25/05351-3
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: July 01, 2025
• End date: July 31, 2025
• Field of knowledge: Health Sciences - Dentistry - Social and Preventive Dentistry
• Principal Investigator: Ana Carolina Magalhães
• Grantee: Gabriela Pellizon Floret
• Supervisor: Marcella Esteves Oliveira
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil
• Institution abroad: University Hospital Tübingen, Germany
• Associated to the scholarship: 24/17354-4 - Evaluation of dentin caries lesions caused by microcosm biofilm - analysis by optical coherence tomography and transverse microradiography: a comparative study, BP.IC

Abstract

The objective of the project is to compare integrated mineral loss and lesion depth of dentin carious lesions using Spectral Domain Optical Coherence Tomography (SD-OCT) and transverse microradiography (TMR), as well as to analyze the cariogenic bacteria present in the microcosm biofilm used for this purpose. Ninety-six bovine dentin samples (4 mm x 4 mm) will be cut and polished. For the formation of the microcosm biofilm, a pooled saliva sample from 10 healthy individuals will be used. In 24-well plates, the samples will be allocated according to two factors under study: biofilm formation time (3, 5, and 7 days) and treatment (0.12% CHX-positive control and PBS-negative control). The samples will be exposed to 1.5 mL of inoculum (human saliva-glycerol + McBain saliva, 1:50) for 8 hours. After the initial 8 hours, the inoculum will be removed, the samples will be washed with PBS (5 seconds), and will receive 1.5 mL of fresh medium (McBain artificial saliva with 0.2% sucrose) for 16 hours, completing the initial 24 hours. From the 1st to the 7th day, according to the formation time, the samples will be treated for 1 minute with CHX or PBS (n=12, biological triplicate n=4) and the sucrose-containing medium will be replaced. The response variables will be: colony-forming units (CFU/mL) of cariogenic microorganisms (Streptococcus mutans/S. sobrinus, Lactobacillus spp) present in the biofilm, and quantification of carious lesions by OCT and TMR (the mineral loss and lesion depth). The data will be subjected to appropriate statistical analysis (parametric or non-parametric test), with p<0.05 considered significant.