Retention force of removable partial dentures with different double crowns

Area of Science:

• Dental prosthetics
• Materials science in dentistry
• Biomaterials engineering

Background:

• Double crowns are utilized in prosthodontics for retention and stability.
• The retentive behavior of double crowns is influenced by design and material composition.
• Understanding long-term retentive behavior is crucial for clinical success.

Purpose of the Study:

• To compare the retentive behaviors of various double crown designs and materials.
• To evaluate the impact of artificial aging on the retention forces of different double crowns.
• To assess the influence of loading conditions on double crown retention.

Main Methods:

• Fabrication of six types of double crowns: metal-based telescopic, zirconia-based telescopic with gold, friction pin crowns (metal and zirconia), and metal-based conical crowns.
• Assessment of retention forces before and after artificial aging.
• Evaluation of retention forces under axial and non-axial loading conditions.

Main Results:

• Initially, friction pin crowns (non-precious metal and zirconia) and metal-based telescopic crowns showed the highest retention forces.
• After artificial aging, double crowns with additional retention elements maintained higher retention forces.
• Significant retention force losses were observed in telescopic crowns with extended surface contact, particularly metal-based designs.

Conclusions:

• Double crown design and material significantly affect initial retention and long-term retentive behavior.
• Telescopic crowns, especially those with extended surface contact, exhibited greater retention force loss after aging.
• Double crowns incorporating additional retention elements demonstrated enhanced resistance to wear and improved long-term retentive stability.