Comparison of Abutments Engagement Configurations in Implant Supported Fixed Partial Dentures

Study design:

This study is designed as a parallel group randomized controlled trial with an allocation ratio of 1:1.

The (PICO) study design: population will be patients from Jordan University Hospital aged 18 years or older, patients who will receive 2 internal connection dental implants to replace 3 posterior missing teeth in the mandible with a 3 unit screw-retained FDP with sufficient bone volume and controlled oral hygiene. The intervention group will receive a screw-retained FDP with conical engaging and non engaging abutment configuration, while the comparator group will a screw-retained FDP with both conical non engaging abutment configuration. The primary outcome is changes in marginal bone levels, and the secondary outcomes include technical and mechanical complications, biological complications, and patient satisfaction.

Both groups will receive 2 internal connection implants in the posterior mandible in healed sites of at least 3 months (guided implant surgery). The surgical procedure will follow standardized protocols, with no variations between groups other than the types of implant abutment connections used.

Blinded assessors will perform radiographic and clinical evaluations at designated follow-up visits: definitive loading, after 6 months of loading, after 2 years loading.

Inclusion criteria

• Adult patients with edentulous span in the posterior mandible of 3 missing teeth.
• Candidates for an implant supported FDP in the posterior mandible.
• Teeth in area of interest extracted at least 3 months prior.
• Bone grafting not needed or only minor GBR needed.
• Controlled oral hygiene.
• Sufficient bone volume.

Exclusion criteria

• Patients with edentulous span of less than 3 missing teeth (not eligible to receive a 3 unit 2 implant supported FDP)
• Patients with healing period of extraction sites less than 3 months.
• Extensive bone grafting required prior to or during implant placement.
• Active Bruxism.
• Heavy smoker (> 10 cigarettes).
• Systemic diseases that might affect bone healing.
• Patients who are not willing or unable to give consent.