Retention of Dome and Flat Magnetic Attachments in Mandibular Implant Overdentures Randomized Controlled Clinical Trial

Complete edentulism of the mandible is frequently associated with compromised denture retention and stability, which may negatively affect mastication, comfort, and patient satisfaction. Mandibular implant-supported overdentures retained by magnetic attachments have been introduced as a reliable treatment option to improve prosthesis retention and function.

Different magnetic attachment designs are available, including flat and dome-shaped configurations. The geometry of magnetic attachments may influence retentive behavior, stress distribution, and overdenture stability during function. However, clinical evidence comparing the retention performance of these attachment designs remains limited.

This randomized clinical trial will include 14 completely edentulous patients aged 50-65 years. All participants will receive two implants placed in the canine regions of the mandible using a fully guided surgical protocol. After a 3-month healing period, patients will be randomly allocated into two equal groups according to the magnetic attachment design used. Group I will receive flat magnetic attachments, while Group II will receive dome-shaped magnetic attachments.

The primary outcome measure will be overdenture retention evaluated using a digital force gauge. Retention measurements will be performed at the time of overdenture loading (baseline), after 3 months of functional use, and after 6 months of functional use. The results will be used to determine whether magnetic attachment design influences the retention of mandibular implant-supported overdentures.

Inclusion criteria

• Completely edentulous mandible for at least 6 months.
• Age between 50 and 65 years.
• Adequate interforaminal bone volume for placement of two implants in the mandibular canine regions.
• Angle Class I maxillomandibular relationship.
• Medically fit patients capable of undergoing implant surgery.
• Ability and willingness to comply with study visits and follow-up procedures.
• Signed informed consent.

Exclusion criteria

• Uncontrolled systemic diseases that may contraindicate implant surgery or affect osseointegration.
• Uncontrolled diabetes mellitus.
• Osteoporosis or metabolic bone disorders affecting implant healing.
• Previous head and neck radiotherapy.
• Presence of oral lesions or untreated oral pathology.
• Temporomandibular joint disorders.
• Parafunctional habits such as bruxism.
• Inability to comply with study protocol or follow-up schedule.