1999 年 12 巻 1 号 p. 64-71
The present study was aimed to compare the masticatory function of patients was an edentulous lower jaw using an Overdenture with O-ring attachment and patients with an edentulous lower jaw using an Overdenture with a magnetic attachment that we developed.
Integral® implants (Calcitek Inc., U.S.A.) with a diameter of 3.25 mm and a length of 8,10,13 or 15 mm were used. The latter overdenture was produced by shaving an SUS 447 J stainless steel block. HICOREX SUPER J® 3515 (Hitachi Metal Co.) was used on the inner surface of the latter denture.
Masticatory function was high for both the O-ring type overdenture and the magnetic attachment type overdenture, with little difference between the two. The O ring rubber deteriorated markedly after 3 years of use. Magnetic attachments manufactured by casting can be prone to corrode. This problem may be avoided if the attachment is designed to be directly attachable to the implant. If a removable type keeper is used in the magnetic attachment type overdenture, it would be possible to avoid problems when the patient must undergo MRI, and to deal with and for the alteration of Overdenture. The removable type keeper also makes it possible for the patient to use O ring or other types of overdentures when needed, in place of the magnetic type overdenture.