Immediate Overdenture With magnetic Attachment

Takako Ono *, Hitoshi Toyoma*,**, Tomohiko Isigami*,** , Tetsuo Ohyama*,** , Shigeru Ohno*, Shinya Nakabayashi*, Yutaka Mitsuhashi*, Ryuji Nakajima*

*Department of Partial Denture Prosthodontics, Nihon University School of dentistry, Japan

**Division of Oral and Craniomaxillofacial Research, Dental Research Center,
Nihon University School of Dentistry, Japan

Introduction

An immediate overdenture using magnetic attachment is reported hereinafter. Even when the amount of bone supporting tooth is insufficient for the prosthetic treatment using a denture, the preservation may become possible by intending an improved crown root ratio through cutting the crown of tooth without extraction and simultaneously by intending a reduced burden through lowering the power point. In such a case, it is sometimes recommended to prepare an overdenture previously by prospecting the postoperative circumstance and to perform the reception of dentures simultaneously with the preparation for root capping. Since the reception of dentures is performed immediately after preparation for root capping, such a denture is tentatively called “immediate overdenture.”

As the advantages of using this immediate overdenture, an ensured vertical dimension by residual tooth until the reception of dentures as well as a maintained sense of periodontal membrane even after reception of dentures are listed.

Here, an example of clinical case is presented in which a good masticatory function could be recovered by ensuring the retention and stability of denture while simultaneously performing the reception of immediate overdenture after a post keeper was applied to the residual tooth.

CASE 1

The patient was a 56-year-old female who had visited our clinic with an chief complaint of occlusal pain on the upper right side. On these films, the photos in oral cavity and X-ray films taken during the first inspection are shown above. (Fig. 1 & 2)

There was a bridge of abutment teeth at the No.14 and No.16 distal roots set and her X-ray examination revealed severe vertical bone resorption at the No.16 distal root, the findings of which led us to perform an emergent treatment by removal of the bridge due to failed preservation followed by extraction of the No.6 distal root.

Although severe horizontal bone resorption was also observed at the No.14 and No.17, the dental mobility was rated as Grade I - II and thus the occlusal stop could be ensured after removal of the bridge.

Since the daily life after operation where a direct retainer is established on the residual tooth with poor bone supporting capacity to set a denture was worried, we decided to treat an immediate overdenture with improving the crown root ratio.

In the case of resembled unilateral distal extension missing as seen in our patient, it is usually intended to stabilize the denture by establishing an indirect retainer on the opposite side. Because our patient refused a large denture, however, a unilateral extension base denture was attempted as a provisional denture prior to the settlement of definitive denture and the clinical course was followed.

Her perioperative course is shown above..

An endodontic treatment is first required. the roots canal treatment were performed by approaching from the occlusal surface without drilling the cusp in order to ensure the vertical dimension of occlusion (Figs. 3 & 4) and the crown of teeth were then cut simultaneously with the completion of immediate overdenture followed by the reception of denture. (Figs. 5 & 6)

According to a routine procedure, the preparation for root capping was then performed followed by the preparation of temporary copings with post keeper using room self- curing resin and its temporary cementation. (Fig. 7) Magnetic assemblies were set to the immediate overdenture as seen above. (Figs. 8 & 9)

It was confirmed that the retention and stability of denture as well as the state of abutment tooth were all good from the observed clinical course after reception of immediate overdenture. Therefore, the temporary copings with post keeper were then replaced with the final copings with post keeper to prepare the definitive denture as shown in Figs. 10 and 11.

The post keeper used in this patient is shown above. (Fig.12)

There are 2 types of HICOREX post keeper manufactured by Morita Corporation including 3013 PK of 3.0 mm in diameter and 3513 PK of 3.5 mm in diameter, either of which is adequately selected based on the site of application and the case involved.

The length of post is scaled at 1 mm intervals with a ditch and adjusted according to the case involved adequately. In addition, a bar corresponding to the post applied is available on the market. (Fig.13)

In the present case, however, it was little regretted after establishment of the definitive denture that a post keeper of smaller diameter with a higher degree of freedom might be more useful.

CASE 2

The case received an immediate full overdenture utilizing a post keeper is reported.

The patient was a 60-year-old male who had visited our clinic for detailed examination on his repeatedly detached upper bridge. X-ray films taken during first inspection are shown above. (Fig. 14)

He said that a one piece bridge covering the No.15 to the No.25 sites was set but its detachment has occurred repeatedly.

From his X-ray examination, horizontal bone resorption of about 1/2 to 1/3 of the root length was found in the upper residual tooth and it thus seemed difficult to prepare a bridge newly. Furthermore, a further improvement of crown root ration was considered necessary in order to preserve it as an abutment tooth. Because the patient had a vomiting reflex and thus wished to set a roofless denture as a definitive denture, an immediate full overdenture of roofless type was prepared, intending the retention and stability using magnetic attachments combined with post keeper. After arrangement, a definitive denture was completed.

The photos in oral cavity taken during operation and the immediate overdenture used are shown above. (Fig. 15)

Preparation for root capping was done after removal of the post keeper. At that time, extraction was performed because the No.22 was judged impossible to preserve.

Thereafter, temporary copings with post keeper were prepared at the No.14 and No.25 sites in a relatively good condition for bone supporting among those resided followed by temporary cementation. (Fig. 16) Dental magnetic attachments were set to the immediate overdenture. (Figs. 17 & 18)

While confirming the retention and stability of the denture applied, a definitive denture will be established as soon as possible since a favorable outcome was obtained by using this immediate full overdenture of roofless type.

CASE 3

The case of bilateral extension base denture in which a conventional immediate denture is combined with immediate overdenture is reported.

The patient was a 55-year-old male who had visited our clinic with main complaints of residual tooth mobility and pain as well as ill fitting of upper and lower dentures. (Figs. 19 & 20)

From his X-ray examination, it was confirmed that the No.44, No.45 and No.47 were impossible to preserve and that horizontal bone resorption of about 1/2 - 1/3 of the root length was observed at the No.34 and No.35 which resulted in teeth separation as seen above. In addition, as seen in the photos in oral cavity, a buccal inclination was also found. Probably due to a lack of undercut volume required for clasp retention at the No.33 site, the retention was tried to obtain by utilizing magnetic attachments at the No.34 and No.35 sites.

In this case, it was decided to perform a relining manipulation in order to stabilize the upper old denture followed by preparation of the lower immediate overdenture.

The patient's oral pictures taken during operation and the immediate overdenture used are shown above.

Simultaneously with the temporary cementation of temporary coping with post keeper at the No.34 and No.35 and extraction of the No.44, No.45 and No. 47, an immediate overdenture was set .(Figs. 21, 22 & 23)

In this case, as compared with a conventional immediate denture, the retention and stability of denture could be attained soon after reception of denture by applying an immediate overdenture while ensuring the present occlusal vertical dimension, all of which treatments successfully resulted in good outcomes not only on the occlusion and the ability of mastication but also on the pronunciation function.

Consideration

Although the application of post keeper generally requires a relatively prolonged chair time at settlement of immediate overdenture, this approach is advantageous in that a strong retention force can be expected from the early stage of treatment and immediately restored occlusion and high patient's satisfaction are achieved without causing unstable denture or masticatory dysfunction.

In summary, the application of immediate overdenture for protection and establishing the balanced preservation of residual tooth in relation to the oral circumstance is considered useful treatment strategy and provides an index for definitive denture.

Discussion Board