Mapping the role of oral cavity physiological factors into the viscoelastic model of denture adhesives for numerical implementation

• Published in: Journal of applied biomaterials & functional materials Vol. 21; p. 22808000231201460
• Main Authors: Ramakrishnan, Anantha Narayanan, Röhrle, Oliver, Ludtka, Christopher, Koehler, Josephine, Kiesow, Andreas, Schwan, Stefan
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.01.2023; Sage Publications Ltd; SAGE Publishing
• Subjects: Adhesive strength; Adhesives; Dental materials; Dentures; Humans; Loss modulus; Mathematical models; Mechanical properties; Mouth; Oral cavity; Parameters; pH effects; Physiological effects; Physiological factors; Physiology; Prony series; Prostheses; Relaxation time; Rheological properties; Saliva; Swelling; Temperature; Viscoelasticity; numerical simulations; Denture adhesive; prony series discretization; viscoelasticity; time-temperature superposition; physiological factors
• ISSN: 2280-8000; 2280-8000
• DOI: 10.1177/22808000231201460

Physiological parameters of the oral cavity have a profound impact on any restorative solutions designed for edentulous patients including denture adhesives. This study aims to mathematically quantify the influence of three such variables, namely: the temperature, pH, and the swelling of such adhesives under the influence of saliva on its mechanical behavior. The mathematical quantification is further aimed to implement a material model for such adhesives which considers the impact of such physiological factors. The denture adhesive is experimentally investigated by means of rheological steady state frequency sweep tests to obtain the relaxation spectrum of the material. The relaxation behavior is measured for a wide range of oral cavity temperatures and pH. Also, the adhesive is hydrated and upon swelling to different levels again tested to understand the impact of swelling on the mechanical behavior. The experimentally measured continuous relaxation spectrum is modeled as a viscoelastic material using a discrete set of points based on the Prony series discretization technique. The relaxation spectrums for various temperatures are compared and the possibility of a time-temperature superposition is explored for the model. Similarly, the measured values of Storage and loss modulus are investigated to understand the role of pH and swelling. The results in this study clearly indicated a horizontal shift in the relaxation behavior with increase in temperature. And hence, the time-temperature shift factor was calculated for the adhesive. The relaxation spectrum also showed a strong correlation with swelling of the adhesive and the pH. The influence of these two parameters were captured into the model based on the relaxation time parameter in the Prony series approach. Based on this study the impact of these parameters could be appreciated on the performance and mechanical behavior of denture adhesives and implemented into a Prony series based viscoelastic material model which can be used with numerical simulations.