Effect of home reliner on occlusal relationships and oral mucosa: viscoelastic analyses by smoothed particle hydrodynamics simulation

Smoothed particle hydrodynamics method applied to oral region: A narrative review

Traditionally, simulation studies in dentistry have relied on the finite element method (FEM). However, the smoothed particle hydrodynamics (SPH) method, which represents objects as particle collections without the use of meshes, has gained recent attention. Despite its application in dentistry, there is currently a lack of comprehensive literature summarizing the specific applications of the SPH method in the oral region. This review aims to provide a summary of studies that have utilized the SPH method in dentistry, focusing on its applications in analyzing large deformations, such as dental ceramic collisions, soft material analysis (e.g., denture adhesive), and virtual training simulations for dental treatments. By combining the advantages of the SPH and FEM methods, more accurate simulations can be achieved, and further applications of the SPH method in dentistry are anticipated.

Stress distribution analysis of oral mucosa under soft denture liners using smoothed particle hydrodynamics method

This study aims to simulate the stress distributions of oral mucosa under different soft denture liners using the smoothed particle hydrodynamics (SPH) method. The Young's modulus and viscosity of denture liners composed of silicone (Sofreliner Super Soft and Sofreliner Tough Medium, Tokuyama Dental), acrylic (Vertex Soft, Vertex Dental), and a tissue conditioner (Visco-gel, Dentsply Sirona) were measured using a creep meter. A numerical simulation model that represents the stress distribution of oral mucosa under soft denture liners was also developed using the SPH method. The oral mucosa was divided into four regions: A) buccal border, B) buccal shelf, C) crest of residual ridge, and D) lingual border. For each region, the von Mises stress (hereafter, referred to as "Mises stress") of the oral mucosa was calculated. Based on a creep test, Sofreliner Super Soft and Sofreliner Tough Medium silicone liners showed an elastic behavior, whereas Vertex Soft acrylic liner and Visco-gel tissue conditioner showed a viscoelastic behavior. In addition, Sofreliner Super Soft and Visco-gel exhibited a large strain. The numerical simulation revealed that the mean Mises stress was the highest in region A and lowest in region D. Vertex Soft acrylic liners resulted in a statistically lower Mises stress on the oral mucosa compared to the other three soft denture liners. Different soft denture liner materials lead to different stress distributions on the oral mucosa. The acrylic soft denture liners cause a lower Mises stress on the oral mucosa than the silicon soft denture liners. This suggests that acrylic soft denture liners would be more effective for manufacturing painless dentures than silicone soft denture liners.