Evaluation of Thermal Variation and Pulp Oxygenation During Photopolymerization: In Vitro and In Vivo Study Using Thermocouple and Laser Doppler Flowmetry

• Grant number: 25/01003-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Rodrigo Ricci Vivan
• Grantee: Luana Maria Rodrigues
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

Proper and complete photopolymerization is essential for the success of restorations made with photopolymerizable resin-based composites, which has led to the development of various photopolymerization units. During the photoactivation process, there is an increase in temperature, and the pulp effects resulting from this are still not fully understood. The aim of this study is to evaluate in vitro the thermal effects and in vivo the circulatory effects on the pulp tissue during exposure to different photopolymerizers. For the in vitro experiment, extracted human central incisors will be used, and temperature variation in the pulp chamber will be assessed with the use of a thermocouple before and after exposure to photopolymerizers. For the in vivo study, 20 healthy volunteers will be evaluated for pulp oxygenation through laser Doppler flowmetry before, during, and after the application of photopolymerizers. The sample size was calculated based on statistical power, with 10 teeth required for the in vitro study and 20 volunteers for the in vivo study. The experimental protocol will be strictly controlled, with the photopolymerizers activated for specific times according to the energy density required to reach 16 J/cm². The data will be analyzed statistically to compare pre-intervention, during, and post-intervention measurements, using parametric or non-parametric tests based on the normality and homogeneity of the data. This study will provide essential information about the thermal and hemodynamic impacts of photopolymerization, contributing to the optimization of clinical practices in Endodontics.