JACOBS, R. Maxillary bone resorption in patients with mandibular implant-supported overdenture or fixed prostheses. J. Prosthetic Dent. 1993, 70, 135-140
HEMMINGS, K. W. Complications and Maintenance Requirements for Fixed Prostheses and Overdentures in the Edentulous Mandible ; A 5-year Report. The Int. national J. Oral. Maxillo. ficial Implants. 1994, 9, 191-196