Advanced biomaterials used for a new telescopic retainer for removable dentures

Area of Science:

• Biomaterials Science
• Dental Materials
• Tribology

Background:

• Cast-metal telescopic crowns in removable dentures often show unpredictable changes in retentive force over time.
• This variability can negatively impact denture function and patient satisfaction.

Purpose of the Study:

• To develop and evaluate a new retainer for removable dentures with improved tribological properties.
• To compare the retentive force and wear resistance of a novel ceramic-gold retainer against conventional cast-metal designs.

Main Methods:

• A new retainer design using a conical all-ceramic abutment crown and an electroplated gold coping was created.
• Retentive forces were measured using a universal testing machine under varying loads (5-400 N).
• Wear was simulated through 100,000 joining/separating cycles in artificial saliva, with SEM analysis for fit and surface evaluation.

Main Results:

• Conventional gold and titanium retainers showed increased retentive forces with load and unpredictable changes after wear, with significant surface wear observed.
• The novel ceramic/electroplated gold retainer maintained consistent retentive forces (mean 5.03 N) irrespective of load or wear.
• The ceramic-gold specimens exhibited no wear traces and superior fit (median gap 4.9 µm).

Conclusions:

• Replacing cast metals with ceramics and electroplated gold in denture retainers offers clinically advantageous tribological properties.
• The novel ceramic-gold retainer demonstrates high wear resistance and stable retentive forces, suggesting improved long-term clinical performance.
• This design represents a significant advancement in removable denture technology, enhancing durability and predictability.