Explore the creep characteristics of PMMA in dentistry

The creep characteristics of PMMA in dentistry are influenced by multiple factors. The specific analysis is as follows:

Creep phenomenon and influencing factors

Creep definition: The phenomenon where the deformation of a material gradually increases over time under constant stress is called creep. For dental PMMA, creep may cause deformation of the denture base, thereby affecting its fit and service life.

Influencing factors

Temperature: The higher the temperature, the greater the creep deformation of PMMA. In the oral environment, the temperature is relatively stable, but the frictional heat generated during chewing may have a certain impact on creep.

Stress: The greater the stress, the greater the creep deformation of PMMA. The pressure generated during chewing is the main source of stress borne by the PMMA denture base.

Time: The creep rate is exponentially related to time. As time increases, the creep phenomenon intensifies.

The material itself: Factors such as the molecular structure of PMMA, powder size, density, and the amount of residual monomers will all affect its creep performance. Reducing porosity and monomer residue, increasing powder size and density, and using copolymers and other methods can enhance the creep resistance of PMMA.

The influence of creep on dental applications

Deformation of denture base: Creep may cause deformation of the denture base, reducing its fit with oral tissues and affecting the stability and comfort of the denture.

Microcrack generation: Creep may also lead to the formation of microcracks, which may further expand, causing the fracture and loosening of the denture base.

Methods for improving creep characteristics

Optimize material formula: By adjusting the molecular structure of PMMA, adding copolymers or reinforcing materials, etc., its creep performance can be improved.

Improving processing techniques: By adopting advanced processing techniques such as microwave curing technology, the porosity and monomer residue can be reduced, and the creep resistance of PMMA can be enhanced.

Regular maintenance and replacement: For the PMMA denture bases that have already been used, regular inspection and maintenance should be carried out to promptly identify and address issues such as deformation or micro-cracks. When necessary, new denture bases should be replaced in a timely manner.