Variables affecting silicone-polymethyl methacrylate interfacial bond strengths

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Silicone soft liners improve denture comfort and function.
• Ensuring a durable bond between the soft liner and the polymethyl methacrylate (PMMA) denture base is critical for longevity.
• Silane coupling agents are used to improve adhesion between dissimilar materials.

Purpose of the Study:

• To evaluate the impact of different polymerization methods on interfacial bond strength.
• To assess the effectiveness of various silane coupling agents in bonding Molloplast-B and PMMA.
• To compare bond strengths using premixed versus fresh-mixed silane agents.

Main Methods:

• Standardized PMMA blocks were prepared and stored in humidity.
• Silicone liners were processed with premixed or fresh-mixed silane agents.
• Polymerization was performed using wet-heat or dry-heat methods.
• Peel bond strength was measured using a 180-degree angle test on an Instron machine.

Main Results:

• No significant difference in bond strength was observed between Lucitone and Lucitone 199 PMMA.
• Wet versus dry heat polymerization methods did not significantly affect bond strengths.
• Premixed silane showed slightly improved bond strength in wet polymerization.
• Fresh-mixed silane demonstrated slightly increased bond strength with dry-heat polymerization.

Conclusions:

• The choice between Lucitone and Lucitone 199, and wet or dry polymerization, has minimal effect on the bond strength of silicone soft liners to PMMA denture bases.
• Fresh-mixed silane coupling agents yielded a distinctly superior bond strength under the study's conditions.
• Optimizing silane application is key for robust denture liner adhesion.