Two or four implants for maxillary overdentures in edentulous patients: 1-year results of a randomized controlled trial.

Maxillary 4-implant overdentures perform better than maxillary 2-implant overdentures with a bar attachment system in terms of implant and overdenture survival and therefore remains the gold standard. However, both overdentures perform similarly in terms of MBLC, clinical, masticatory, and PROMs.