Which dentine analogue material can replace human dentine for crown fatigue test?

Area of Science:

• Biomaterials Science
• Mechanical Engineering
• Dental Materials Science

Background:

• Human dentine's mechanical properties and fatigue behavior are crucial for dental restorations.
• Developing reliable dentine analogue materials is essential for accurate laboratory testing of dental crowns.
• Existing analogues may not fully replicate dentine's complex mechanical responses under fatigue loading.

Purpose of the Study:

• To evaluate woven glass fibre-filled epoxy (G10) and glass fibre-reinforced polyamide-nylon (RPN) as potential replacements for human dentine (HD) in crown fatigue laboratory tests.
• To compare the mechanical properties and fatigue behaviors of G10 and RPN against HD using experimental, analytical, and numerical approaches.

Main Methods:

• Investigated flexural strength, elastic modulus, and indentation hardness of G10, RPN, and HD.
• Subjected resin-bonded monolithic lithium disilicate crowns on G10, RPN, and HD abutments to wet cyclic loading.
• Utilized Finite Element Models (FEM) for stress distribution analysis and lifetime prediction, alongside fractographic observations.

Main Results:

• While flexural strengths differed significantly, flexural moduli and indentation hardness showed no significant differences between HD and RPN.
• Glass fibre-reinforced polyamide-nylon (RPN) and G10 exhibited comparable mean fatigue failure loads and cycles to failure as human dentine (HD).
• RPN demonstrated higher stability and lower deviation in fatigue test results compared to G10, as indicated by Weibull analysis and FEA.

Conclusions:

• Dentine analogue materials can exhibit similar elastic properties and fatigue performance to human dentine.
• However, variations in fatigue reliability exist among these analogues.
• Glass fibre-reinforced polyamide-nylon (RPN) emerges as a superior substrate, offering enhanced reliability and predictability for laboratory study outcomes.