A case report of a removable partial denture using magnetic attachmentsof different designs on intermediate missing mandibular molars
M. SONE1, D. MATSUMOTO1, M. NUMAZAWA1, S. UCHIDA1, Y. INOYAMA1, D. SAKAMOTO1,K. OKAMOTO1, and M FUJISAWA2.
1

Division of Removable Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai
University School of Dentistry2
Division of Fixed Prosthodontics, Department of Restorative and Biomaterials Sciences, Meikai
University School of Dentistry

Abstract
In this presentation, we report a case in which two dentures with different designs of magnetic
attachments were attached to intermediate missing mandibular molars.
The patient, a 59-year-old male, complained of masticatory dysfunction. After the initial preparation, thedistal root of the mandibular right second molar was fitted with a coping magnetic attachment inconsideration of its load-bearing capacity as an abutment tooth, and we decided to fabricate an
extracoronal magnetic attachment using an EC Keeper Tray (GC, Japan) for the mandibular right first andsecond premolars.
The definitive denture had the first molar as a homemade metal tooth and the second molar as a hardresin tooth (SR-Orthosit-PE; Ivoclar-Vivadent AG, Liechtenstein). In addition, GIGAUSS (GC) was usedfor a magnetic attachment (the coping type was the D400), and the D600 was applied to the extracoronal
type. One year after the installation of the right denture, in response to the patient's request to use thesame magnetic attachment as the right side, the first and second premolars on the left side were
equipped with similar extra-crown attachments, and the dentures were made of the same material.

Introduction
In the partial denture design, when intermediate missing teeth are on the right and left sides, due to thepatient's need for wearing comfort, we sometimes design two dentures without a major connector. In thispresentation, we report a case in which two dentures with different designs of magnetic attachments wereattached to intermediate missing mandibular molars.

Clinical History
Clinical History: The patient, a 59-year-old male, complained of masticatory dysfunction. He had apartially edentulous maxilla (Kennedy Class Ⅱ) and a history of arrhythmia. He complained that he wanted

Fig. 1 Intraoral view at the first visit

to seat the denture firmly on his right jaw, but he did not want the implant treatment due to his current
systemic history (Fig. 1).
Treatment Procedure: Based on dental X-ray photographs (Fig. 2) and periodontal disease examination(Fig. 3), the distal root of the mandibular right second molar was fitted with a coping type of magnetic
attachment (Fig. 4) in consideration of its load-bearing capacity as an abutment tooth. We decided tofabricate an extracoronal magnetic attachment using an EC Keeper Tray (GC, Japan) for the mandibular
right first and second premolars (Figs. 5 and 6).

  


Fig. 2 X-ray photographs at the first visit

Fig. 4 Coping typeof magnetic attachment                      









Fig. 3 Periodontal disease examination at the first visit

Fig. 5 Extracoronalmagnetic attachment

Fig. 6 EC Keeper Tray

After fixing the coping type of magnetic attachment to the oral cavity, a pick-up impression was taken in
the oral cavity for making a working model, and a framework of the denture was fabricated on it (Fig. 7).
The definitive denture had the first molar as a homemade metal tooth, taking into account the space of thehousing portion of the extracoronal magnetic attachment; the second molar was a hard resin tooth (SROrthosit-PE; Ivoclar-Vivadent AG, Liechtenstein) (Fig. 8). In addition, GIGAUSS (GC) was used for amagnetic attachment (the coping type was the D400), and the D600 was applied to the extracoronalattachment.

Fig. 7 Pick-up impression and denture framework(Right side)

Fig. 8 Definitive denture(Right side)

One year after the installation of the right denture, periodontal disease of the second molar on the left
side of the mandible, which was the abutment of the left bridge, advanced, and the tooth was extracted. Inresponse to the patient's request to use the same magnetic attachment as the right side for subsequent defectprostheses, the first and second premolars on the left side of the mandible were equipped with extra-crownattachments similar to the abutment teeth, and the dentures were made of the same material. As a support
function to replace the root attachment on the right side, a mesial rest was added to the third molar on theleft side of the mandible (Figs. 9 and 10).

Fig. 9 Pick-up impression and denture framework(Left side)

Fig. 10 Definitive denture(Left side)

Conclusion
Magnetic attachments can be used as support teeth by reducing the lateral pressure as coping types, even
if the remaining teeth have problems with the crown-to-root ratio due to the absorption of alveolar bone.
In addition, if the crown-to-root ratio is good, it is possible to produce highly stable dentures by having
the abutment teeth carry the retention force and bracing force as an external type of crown (Fig. 11).1,2) In
this case, we applied these advantages and produced a denture. As a result, OHIP-14, which is related toQOL, was two points from the minimum value. By analyzing the amount of glucose discharge duringgumi-jelly chewing, mandibular movements were quantitatively evaluated to be 188 mg/dl (right side) and228 mg/dl (left side). We plan to confirm the postoperative course while performing regular maintenancein the future.

Fig. 11 Intraoral view of treatment procedures

References
1.

2.

M. SONE, H. HAMASAKA, Y. OKAWA, S. SOMEKAWA, M. MASUDA, A. MATUI, Y.
TOYOTA, F. OKUTSU, T. MATSUKAWA, K. OKAMOTO and S. OHKAWA: Relationshipbetween denture design and prognosis in removable denture using magnetic attachments. JJ Mag
Dent, 24(1), 68-77, 2015
Y. TANAKA: SHIN JISEI ATATCHIMENTO (New Dental Magnetic Attachment). ISHIYAKUPUBLISHERS INC, Tokyo, 2016.