Heat-released stress in acrylic dentures.

Area of Science:

• Dental Materials Science
• Prosthodontics

Background:

• Acrylic resin denture bases are susceptible to dimensional changes.
• Accurate denture fit is crucial for patient comfort and function.

Purpose of the Study:

• To investigate the thermal dimensional stability of acrylic resin denture blanks.
• To identify factors influencing denture distortion during fabrication and finishing.

Main Methods:

• Heating acrylic resin denture blanks in water at various temperatures.
• Measuring dimensional changes and assessing fit on gypsum casts.
• Evaluating heat generation during grinding procedures.

Main Results:

• Significant dimensional changes, affecting fit, occur above 90°C.
• Intermolar distance changes poorly correlate with overall fit, indicating complex dimensional behavior.
• Grinding acrylic resin can generate sufficient heat to cause localized distortion.

Conclusions:

• Denture resins are sensitive to heat during processing and finishing.
• Dentists, assistants, and technicians must be aware of thermal sensitivity to prevent denture distortion.
• Proper finishing techniques are essential for maintaining denture accuracy and fit.