Evaluation of the incorporation of propolis into chitosan nanoparticles in experimental dentifrices for dentin hypersensitivity: an in vitro study

• Grant number: 24/12845-0
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Silmara Aparecida Milori Corona
• Grantee: Silmara Aparecida Milori Corona
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Renata Siqueira Scatolin

Abstract

Dentin hypersensitivity is a common complaint in dental clinics. Toothpastes composed of nanoparticles combined with natural active ingredients can be promising for greater tubular occlusion and ease of use by patients. The objective of this study is to investigate in vitro the effect of applying experimental toothpastesincorporating propolis extract in chitosan nanoparticles on dentin simulating hypersensitive areas. For the study, 135 specimens of bovine root dentin will be used, initially immersed in 0.5M EDTA to open the dentinal tubules. These will bedivided into 5 groups: Non-fluoridated base toothpaste - negative control; Commercial desensitizing toothpaste Elmex® Sensitive Professional - positive control (Pro-Arginine, Zinc Phosphate); Toothpaste containing 2.5% propolis extract; Toothpaste containing 0.125% chitosan nanoparticles; Toothpaste containing 2.5% propolis extract incorporated in 0.125% chitosan nanoparticles. Subsequently, the specimens will undergo erosive/abrasive cycles with immersionin citric acid (2 minutes, 0.3%, pH 3.2, 4 times/day) and the treatment will consist of brushing the samples with each of the toothpastes (2 N, 45 strokes) for 5 days. Finally, a new erosive challenge with citric acid (pH 3.2 for 1 min.) will be performed. The quantitative response variables will be obtained through analyses of root dentin permeability, tubule count, surface microhardness, and profilometry. The qualitative variable will be assessed using scanning electron microscopy analysis. The obtained data will be subjected to distribution analysis, and datahomogeneity will be verified using the Kolmogorov-Smirnov test. Statistical analysis will use a significance level of 5%. (AU)