Effect of Placement of Magnetic Attachment on Retentive Force of Overdenture

Y. Umekawa^1,2, Y. Ogawa¹, K. Ohtani^1,2, S. Ohno¹, T. Ishigami^1,2

¹Department of Partial Denture Prosthodontics, Nihon University School of Dentistry

²Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry

Abstract

Mandible complete denture for edentulous fail out when losing border seal at precipitous tongue movement or open mouth. Implant with attachment is useful for retaining overdenture. Lot of magnetic overdenture cases is reported with good results. The aim of this study is to evaluate retentive force of mandible overdenture with various layouts of implants with magnetic attachments by using universal testing machine.

Mandible bone model and overdenture model was made by acryl resin and residual mucous membrane model was made by silicone rubber impression material. Artificial saliva was made by moisturizing gel. Magnetic attachment was placed median mandible, canine and molar. Tensile test was performed at incisor point, left second molar and center of second molars of overdenture model by original testing jig and universal testing machine at 5.0 mm/min of cross head speed. The test was repeated five times each condition and averaged. Statistical comparison was performed using Tukey’s test (P<.05).

Magnetic attachment significant increases retentive force of mandible overdenture. Median mandible magnetic attachment significantly increases of retentive force against anterior dislodgement of overdenture. Three front placement or four square placement of magnetic attachment increases retentive forces against posterior dislodgement of overdenture.