A clinical case of implant overdenture with magnetic
attachment using CAD/CAM technology
Suzuki Y１，Harada N２，Maruo R１，Imaizumi N１，Muto R１，Shimpo H１, Kurihara D１,Ohkubo C１
Dept of Removable Prosthodontics，Tsurumi University School of Dental Medicine

１2

Dental Technician Training Institute, Tsurumi University School of Dental Medicine

Abstract【Objective】
In recent years, digital dentistry based on computer-aided design and computer-aided
manufacturing (CAD/CAM) has become increasingly popular, and the workflow for thefabrication of removable dentures has changed dramatically. This case was used
CAD/CAM technology for maxillary conventional overdenture and mandibular implant
overdenture (IOD) with magnetic attachments.
【Method】
CAD/CAM dentures were fabricated using DENTCA system (DENTCA Inc., Mitsui
Chemical Inc.). On the initial visit, exclusive plastic trays (DENTCA tray, DENTCA Inc.)
were used for making definitive impression, determination of vertical dimension, andrecording of the centric relation with gothic-arch tracing. On the second visit, 3D printed
try-in dentures were placed in the patient’s mouth, occlusion, retention, stability, andesthetics were checked and corrected. On the final visit, CAD/CAM dentures weredelivered in the patient’s mouth.
【Results, Discussion】
Maxillary conventional overdenture and mandibular IOD with magnetic attachments canbe fabricated using CAD/CAM technology for high strength and accuracy prosthesis.
Introduction
Computer-aided design and computer-aided manufacturing (CAD/CAM) technology has been applied
to removable denture fabrication. CAD/CAM dentures can be fabricated with high precision byreducing because polymerization distortion is eliminated. This case was used CAD/CAM technology
for maxillary conventional overdenture and mandibular implant overdenture (IOD) with magneticattachments.

Patient’s characteristics
The patient was a 65-years old female with partially edentulous maxillary jaw including dental root
fractures #23 and #26 and fully edentulous mandibular jaw including dental implant fractures #47 (Fig.
1, 2). Maxillary and mandibular acrylic partial denture was worn for five years. Her chief complaints
were unstable and difficulties of mastication using existing dentures. There was no significant medicalhistory.

Fig. 1 Intraoral photograph at the first visit

Treatment progresses

2017/ February
AprilJuly・First visits
・Extraction of #23, #26 teeth, and remove of #47 implant.
・Two implants (Magfit MIP fixture, PLATON, Japan) were placed in the regionsof # 33 and # 43
November ・Definitive impressions of both maxilla and mandibular jaws were made and themaxillomandibular relationship was recorded.
・3D printed try-in dentures were placed in the patient’s mouth, occlusion,retention, stability, and esthetics were checked.
・CAD/CAM dentures were delivered to the patient’s mouth.
・ Magnetic attachments (Magfit MIP, PLATON, Japan) were set on theCAD/CAM denture.

Implant placement
Fig. 2 Shema of Mini implant and magnetic attachment
Mini dental implant has been applied as a convenient
treatment option for edentulous patients in cases where
standard-sized Implants cannot be placed for economical
and/or anatomical reasons

Magfit MIP（PLATON）

Fig. 3 Two mini implants were placed at canine regions.

Fig. 4 Magnetic attachment keepers(Magfit MIP flat keeper, PLATON)
were set on the implants.

CAD/CAM dentures were fabricated using DENTCA system

a: Use hard flow polyvinyl siloxane impression material for first impression

b: Apply medium flow polyvinyl siloxane for wash impression. Seatand border mold to capture anatomical landmarks.
Fig. 5 a,b Definitive impressions of both the maxilla and mandible were made with a double impression
technique using polyvinyl siloxane impression materials (Exafine, hard and medium flow types; GCCorp) with custom trays (DENTCA tray, Size M; DENTCA Inc).

Fig. 6 Both impressions were sectioned and separated anteroposteriorlyFig. 7 Gothic arch was traced, and the maxillomandibular relationship was registered using theanterior portions of the impressions.

Fig. 8 Virtual teeth were automatically arranged according to average positions of anatomical
landmark using a digital design system (PreForm v1.9.1 CAD software; DENTCA Inc). 3D printed
try-in dentures were placed in the patient’s mouth, occlusion, retention, stability, and esthetics werechecked and corrected.

Fig. 9 Maxillary and mandibular complete dentures was milled from acrylic resin block andcommercially available denture teeth were bonded with resin adhesive.

Fig. 10 Panorama radiograph at the postoperative visit

Results and Discussion
Maxillary conventional overdenture and mandibular IOD with magnetic attachments can be fabricatedusing CAD/CAM technology for high strength and accuracy prosthesis. Sufficient retention andstability could be provided by the magnetic attachments, and satisfactory aesthetic and function could
be achieved using the DENTCA system.