Effects of sample hardness on human chewing force: a model study using silicone rubber

Area of Science:

• Biomechanics
• Dental Physiology
• Food Science

Background:

• Understanding how food properties influence human chewing is crucial for nutrition and dental health.
• Previous research has focused on various food textures, but the specific impact of sample hardness on chewing force requires further clarification.

Purpose of the Study:

• To investigate the quantitative effects of varying sample hardness on human chewing force and related biomechanical parameters.
• To analyze how sample hardness influences contact area, pressure, and force application during mastication.

Main Methods:

• Utilized silicone rubber models with three distinct hardness levels as food simulants.
• Employed a multiple-point sheet sensor to dynamically measure chewing force, tooth-sample contact area, and applied pressure during natural chewing.
• Recorded measurements using both incisors and molars.

Main Results:

• Harder samples resulted in significantly higher peak force, longer force duration, increased impulse, and greater active pressure.
• Sample hardness did not affect the chewing cycle duration or the time to reach peak force.
• A decrease in tooth-sample contact area was observed with harder samples during incisor chewing.
• Molar biting generated higher peak forces, contact areas, and bite durations compared to incisor biting.

Conclusions:

• Sample hardness is a critical factor that modifies human chewing force and pressure dynamics.
• The observed effects suggest that mechanoreceptors in the periodontal ligament play a key role in modulating the response to food hardness.
• These findings have implications for designing foods with specific textures and understanding masticatory adaptations.