[ESR study on self-curing resin for rebasing during polymerization].

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Context:

• Self-curing resins are widely used in dental prosthetics for rebasing dentures.
• Understanding the polymerization kinetics is crucial for optimizing material properties and clinical performance.
• Electron spin resonance (ESR) provides a sensitive method to detect and quantify free radicals during polymerization.

Purpose:

• To investigate the influence of various factors on the polymerization process of self-curing resin for rebasing.
• To determine the effects of temperature, activator (N, N-dimethyl-p-toluidine) and inhibitor (hydroquinone) concentrations, atmosphere, liquid-to-powder ratio, and mixing time on radical formation and stability.
• To assess the impact of MMA-derivative radicals on HeLa cell growth.

Summary:

• Polymerization kinetics were studied using ESR, revealing an induction time followed by rapid radical concentration increase.
• Higher curing temperatures accelerated radical disappearance, suggesting increased recombination. Increased activator and decreased inhibitor enhanced radical stability.
• Polymerization was faster in air than in water or nitrogen. Resin fluidity decreased with higher temperatures, lower liquid content, and shorter mixing times.
• HeLa cell growth was reduced on resins containing MMA-derivative radicals.

Impact:

• The findings provide critical insights into optimizing the formulation and processing of self-curing resins for improved performance.
• Understanding radical stability and polymerization dynamics can lead to enhanced material longevity and reduced cytotoxicity.
• This research contributes to the development of safer and more effective dental materials.