Creep on a composite resin in water

Area of Science:

• Materials Science
• Polymer Science
• Biomaterials

Background:

• Composite resins are widely used in dental and industrial applications.
• Understanding their long-term behavior under stress, particularly in aqueous environments, is crucial for predicting performance and longevity.
• Hygroscopic expansion can induce internal stresses, potentially affecting material integrity.

Purpose of the Study:

• To quantify the compressive creep behavior of a composite resin in water over 500 hours.
• To establish a predictive model for creep strain based on stress levels and time.
• To calculate the stress induced by hygroscopic expansion at water absorption equilibrium.

Main Methods:

• Compressive creep tests were performed on composite resin samples at stress levels ranging from 0 to 3.5 kg/mm2.
• Tests were conducted in an aqueous environment for a duration of 500 hours.
• Linear regression analysis was applied to creep strain data against compressive stress and time (log scale) to develop predictive models.

Main Results:

• Linear regression models accurately predicted creep strain at various stress levels and time points.
• The composite resin reached water absorption equilibrium within 500 hours.
• The maximum stress due to hygroscopic expansion was calculated to be 0.74 kg/mm2 at equilibrium.

Conclusions:

• Predictive models for creep strain in composite resins can be reliably developed using linear regression.
• Hygroscopic expansion contributes significant stress to composite resins in aqueous environments, with a quantifiable maximum at equilibrium.
• The findings are essential for material selection and design in applications involving prolonged water exposure.