Treatment considerations for maxillary implant overdentures: a systematic review

STATEMENT OF PROBLEM: Implant overdenture treatment for the edentulous maxilla is challenging due to inherent anatomic and biomechanical problems. Moreover, controversy persists as to factors critical for implant and prosthetic success. Established criteria for design of the maxillary implant overdenture are lacking. PURPOSE: This article reviews the literature on maxillary implant overdentures with an emphasis on number, length, and distribution of implants, splinted or unsplinted anchorage systems, maintenance, and patient satisfaction. MATERIAL AND METHODS: A systematic review of the literature was undertaken seeking evidence to establish criteria for treatment considerations for implant overdenture treatment of the edentulous maxilla. A search of English language peer-reviewed literature was completed using Medline between the period of 1988 to 2006, focusing on evidence-based research. This was supplemented with a manual search of selected journals and textbooks. Randomized controlled clinical trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies, and longitudinal retrospective studies were favored in the review, using a general hierarchical classification. Articles that did not focus on or have an impact on implant overdenture treatment on the maxilla were excluded from the evaluation. The last search was conducted on December 31, 2006. Key terms included maxillary, dental implant, and overdenture. RESULTS: The literature demonstrates a limited number of randomized controlled trials and longitudinal prospective and retrospective studies to strongly support treatment consideration premises for the implant overdenture treatment of the edentulous maxilla. CONCLUSIONS: Within the limits of this systematic review, treatment consideration recommendations have been posited given the available evidence. Better designed, longitudinal studies with higher power are required to establish definitive evidence-based treatment planning principles for the maxillary implant overdenture patient.