Implant-retained prostheses: ball vs. conus attachments - A randomized controlled clinical trial

Area of Science:

• Dentistry
• Prosthodontics
• Implantology

Background:

• Edentulous mandibles present challenges for denture stability and patient satisfaction.
• Implant-supported overdentures (IODs) offer a solution, but retention methods require evaluation.
• Comparing different attachment systems is crucial for optimizing IOD treatment outcomes.

Purpose of the Study:

• To compare implant survival, peri-implant health, maintenance needs, and patient satisfaction of two IOD retention systems.
• To assess the long-term performance of ball versus conus attachments in mandibular overdentures.
• To provide evidence-based insights for selecting appropriate IOD attachment systems.

Main Methods:

• A 3-year observational study involving 25 patients with edentulous mandibles receiving two implants each.
• Patients were randomized to receive either ball attachments or prefabricated conus attachments.
• Evaluated parameters included implant survival, peri-implant tissue health, patient satisfaction, and prosthodontic maintenance.

Main Results:

• 100% implant survival was observed over a mean follow-up of 29.6 months.
• No significant differences in peri-implant parameters were found between the groups.
• Inacceptable retention rates were 80% for ball and 75% for conus attachments; patient satisfaction was 64% (ball) and 100% (conus, with dropouts).

Conclusions:

• High implant survival rates were achieved, but prosthetic reconstructions demanded intensive maintenance.
• Patient satisfaction showed a trend towards reduction, particularly with the conus system, raising questions about its cost-effectiveness.
• Manufacturer recommendations for conus attachments suggest using four implants for removable prostheses.