Evaluation of Flexural Strength and Dimensional Stability of Pure Polycaprolactone and Mixture of Polycaprolactone with Shellac and Talc in Different Proportions

Abstract

Introduction: PCL has received FDA approval and CE registration for its use in numerous drug-delivery systems and medical devices. Lately, PCL has garnered attention for the development of biomaterials and green materials for a range of applications. PCL is easy to manufacture and work with since it has better rheological and viscoelastic qualities as compared to its aliphatic polyester substitutes.

There is a need to evaluate the mechanical properties of polycaprolactone as well as different proportions of polycaprolactone combined with talc and shellac for its application in dentistry.

Objectives: This study assessed the flexural strength of polycaprolactone as well as different proportions of polycaprolactone combined with talc and shellac. The material with highest flexural strength was evaluated for its dimensional stability.

Methods: The study analyzed the flexural strength of PCL blended with talc and shellac to identify the most suitable composition for dimensional stability testing. Fifteen specimens were fabricated across three groups—pure PCL, PCL with shellac and talc (50:40:10), and PCL with shellac and talc (70:20:10)—and tested for flexural strength according to ASTM-D790-17 guidelines using a Universal Testing Machine. A stainless-steel die was used to prepare 5 specimens of the group with highest flexural strength and tested for dimensional stability under a stereomicroscope at different time intervals.

Results: Pure PCL (mean flexural strength 41.62 ± 6.10 N/mm²) with highest flexural strength significantly outperformed the other groups and revealed no variations over time, maintaining consistency with the reference die at intervals of 1 hour, 24 hours, and 48 hours.

Conclusions: Polycaprolactone exhibits remarkable flexural strength and dimensional stability.