Clinical evaluation of implant overdentures using magnetic
attachment: retrospective study
Takayama H1,2)，Suzuki Y1,2)，Kurihara D1,2)，Maruo R1,2)，Shimpo H1,2),Ohkubo C1,2)
1)

Dept. of Removable Prosthodontics，Tsurumi University School of Dental Medicine
Center of Oral and Maxillofacial Implantology, Tsurumi University School of Dental Medicine

2)Introduction
Implant overdenture (IOD) is one of the most effectiveness treatment for removable denture
treatment to provide improvement for removable denture. The objective of this retrospective clinicalstudy was to evaluate performance of IOD using magnetic attachment and to identify risk factors forprosthetic complications.

Materials and Methods
This retrospective study evaluated data collected from edentulous and partial edentulous patientstreated April 2003 and November 2018 in Tsurumi University with IOD using magnetic attachment.
Outcome measures were implant and prosthetic survival rates, patient age when IOD delivering,ratio of male and female, location and number of implant.

Results
A total of 14 patients (3 males and 11 females) with 42 implants (30 maxilla and 12 mandibular) and
36 magnetic attachments were included in this study.The mean age of these patients was 65.5 years(in a range from 64 to 80 years) (Fig. 1,2). The patients were treated using a conventional 2-loading
protocol.

Fig.1 Gender ratio

Fig.2 Age GenderA total of 42 implants were placed, 30 (71,4%) in the maxilla and 12 (28,6%)in the mandible. The
positions of implant placement were: incisor (14,3%)；canine (47,6%)；premolar (23,8%) andmolar(14,3%). In mandibular, a greater number of implants were anterior compared to posterior. (Fig.
3). Two different implant systems were used : 30 implants were regular implants and 12 implants
were mini implants(Fig.4). Approximately 2patients (14,3%) were partially edentulous, and12patients (85,7%) were fully edentulous (Figures 5). The most common denture material was resinbase (8 dentures), followed by Co-Cr base (4 dentures) and titanium base (2 dentures) (Fig. 6).

Number of teeth

Number of teeth
Tooth type

Tooth type

MaxillaMandibularFig.3 The position of Implant placement

Fig.4 Type of implantFig.5 Missing teeth situation

Fig.6 Denture modalities

One (maxilla incisor) of 42 implants failed because of lack osseointegration, during the 7 years afterplacement. The implant have functioned at a rate of 97 % (maxilla91,7% mandible 100%). The
failed implamt case was no occlusal contact in spite of remaining maxillary and mandibular teeth(Eichner classification C1), which is caused by excessive occlusal force to the implant. In prosthetic
complication, attachment loosing (maxillary anterior region and mandibular canine region) wereobserved 3 patients, during the 1 to7 years after denture delivered. (Figs.8and 9 ). However someof attachment looseing and detachment may also be attributed to nomal functions, including patient
insertion and removal of the prostheses. Therefore, it seems to be impotant that controls for thesecomplication risks be made at regular intervals in clinic.

Number of troubles
Tooth typeFig.8 Complication

Fig.9 Complication areaConclusions
In this study, 14 patients (mean age 65.5 years, 3 males and 11 females) with 42 implants and 34
magnetic attachments with a maximum follow-up of 16 years were included. One of 42 implants
were failed and attachment loosing were observed 3 patients, but most of the patients were usedwithout any major complaints.The implant over denture with magnetic attachment were exceedingly
for rehabilitation with a high survival rate.