In recent years, the usefulness of implant treatment for prosthetic defects has been widely recognized. However, there are cases in which changes in the design of the superstructure are necessary.

I have experienced a case in which a fixed superstructure was changed to a removable superstructure in consideration of the possibility that the patient would require nursing care in the near future, and I would like to present my case here.

The patient was a 77-year-old woman. Her chief complaint was that her teeth were loose and painful when she chewed. Her gums were swollen. Her systemic medical history included diabetes and osteoporosis under treatment. She was a non-smoker. Redness of her gums and severe periodontal disease were confirmed. After extraction of a tooth with a poor prognosis under hospitalization, a denture was fabricated using the remaining implant body as an abutment using a magnetic attachment.

Implant overdentures (hereinafter referred to as IOD) are extremely useful in today's super-aging society, as they provide high therapeutic effects with a small number of implants, are easy to maintenance, and keep treatment costs low. This is a great treatment method.

When selecting an IOD, we believe that the selection of attachments is very important.

The main attachments are Bar, Ball, Rocator, and Magnetic.Among these, Magnetic has a smaller retention force than others, but It is easy to maintenance and easy to remove, which is advantageous for elderly people.

We believe that the advantage is that it can be applied even if the implant has poor orientation, and the retention force does not deteriorate with use, so it does not require periodic replacement like the Rocator.

This time, we performed a fixed implant Bridge using the Sinus -Lift method for the defective free end of the maxilla, and an IOD using a magnetic attachment for the free end defect of the mandible.

As a result, the occlusal function was improved.

We attempted to restore the patient's appearance, and we would like to report that the patient's progress was good.

【Objective】

We designed and fabricated an esthetic split denture with magnetic attachment for a case of missing maxillary anterior tooth which is difficult to be restored with an implant prosthesis.

【Case Overview】

A split-type metal base denture was designed and fabricated without exposing the metal on the labial side for esthetic consideration. The proximal plate of the denture was fitted to the undercut of the adjacent surface on the defect side and given a swing mechanism incorporating a magnetic attachment. The denture was removed by moving the anterior prosthesis palatally and releasing the contact between the abutment teeth and the proximal plate. The occlusal rest and palatal guide plane were formed on the abutment tooth, and occlusal contact during central occlusal position and eccentric movement was given to the rest and palatal metal up, thereby reducing the load on the swing-lock attachment hinge.

【Results and Discussion】

The application of magnetic attachments enabled the fixation of the swing locks, and provided adequate retention and high patient satisfaction in terms of esthetics and wearability.

Patients with maxillary defect often experience serious difficulties in speech, swallowing, mastication, and esthetics, even if reconstructed using flap. A 60-year-old Japanese male with squamous cell carcinoma of the right maxilla was referred to our department for prosthetic rehabilitation. He underwent radiotherapy and intraarterial chemotherapy, followed by total right maxillectomy and rectus abdominis muscle flap reconstruction. The first maxillofacial prosthesis was made after referral to our department, however, the remaining teeth worsened so that another maxillofacial prosthesis was required. Seven years after first maxillofacial prosthesis were delivered, an overdenture type maxillofacial prosthesis with OP anchor attachment on #23 and magnetic attachment on #27 was applied. After the overdenture type maxillofacial prosthesis was applied, it was possible to obtain maxillofacial prosthesis stability. The objective hypofunction evaluation showed acceptable results and enabled the patient's quality of life to be improved.

This report describes a case in which insufficient remaining teeth impacted the effectiveness of maxillofacial prosthetic rehabilitation and reports on the applicability of magnetic attachments for the retention of dentures equipped with speech aids. This method is aimed at improving the stability and functionality of these dental prostheses. A 75-year-old woman with velopharyngeal dysfunction due to left maxillary cleft lip and palate presented with an unstable maxillary overdenture equipped with a speech aid, which had a disengaged O-ring attachment on the left maxillary central incisor. It was replaced with a magnetic attachment and the speech-aid prosthesis was adjusted. Functional evaluation was performed with the adjusted prosthesis, and a significant reduction in nasalance during speech was observed. Assessment of masticatory performance demonstrated that the patient could eat a wide variety of foods without substantial difficulty. The magnetic attachment was weak against lateral force, but it improved tongue comfort compared with the O-rings when the prosthesis was not in use. Further discussion and consideration of the effective use of magnetic attachments in maxillofacial prosthetics is expected.

Purpose

Magnetic attachments require careful installation of magnetic assemblies (MAs) because a small air gap can cause a significant reduction in attractive force. The author reported a new method for IOD and IRPD using a cast frame with metal housings and a permanent heat-cured resin base plate at the 25th and 29th Annual Meetings of JSMAD. In this report, we describe the failure events that occurred in IRPD cases using this method.

Case Summary

3 cases were all in which keepers were applied to 3 or more implants and some kind of retentive device was applied to the remaining teeth.

Case 1: A MA fell out with the entire upper resin, but was fixed with Superbond and was repaired.

Case 2: The cast Aker’s clasp was broken, but the patient keeps wearing the denture as it is.

Case 3: The abutment tooth with a keeper was fractured and was replaced to an implant

Results, Discussion

Five to nine years passed after the dentures were delivered, various problems were observed. We would like to investigate the causes of these problems and solve them in the future. However, all patients are still wearing the dentures, and it is more certain that the dentures are useful in preserving periodontal tissues by reducing the load of occlusal forces on the remaining teeth.

The aim of this presentation is to consider the utility of implants and magnetic attachments in the case of complete overdentures with different skeletal types. Those upper complete overdentures in the maxilla of two patients diagnosed class II and class III skeletal types were not enough getting stability due to unique problems of remaining teeth position and skeletal types.

Case 1 First visit: October 2012, 62-year-old female.

This patient exhibited skeletal class Ⅱ type. The upper prosthesis transitioned from a fixed bridge to a complete denture. Dental implants was placed in 6┴6, and a magnetic attachment was attached.

Case 2: First visit: January 2013, A 58-year-old male.

This patient exhibited skeletal class Ⅲ type. The upper prosthesis was transitioned from using clasps denture to a maxillary complete denture with the remaining 2┴235 teeth and placed 76┘dental implants and attached the magnetic attachments.

Those problems were solved by using dental implants and magnetic attachments for modified fulcrum lines of the residual roots and retentive force. It has been suggested that the use of dental implants and magnetic attachments were very useful in cases with such complex problems.

In this presentation, we report on a case in which occlusal reconstruction was performed by attaching dentures with different types of magnetic attachments for problems after oral implant placement.

The patient, a 66-year-old female, complained of aesthetic dissatisfaction and masticatory dysfunction. Six years earlier, she had undergone full-mouth rehabilitation–including implant treatment at a local clinic–and had been doing well since that time. However, one year earlier, a root fracture had occurred in the teeth opposite the implant placement site. It was suggested that she have the fractured teeth extracted and wear telescopic crowns using the implant as an abutment. The superstructure was removed, but the abutment screw broke during the procedure. Therefore, the patient visited the department of prosthodontics at our university hospital.

As a result of treatment, a maxillary definitive prosthesis was fabricated with a non-palatal overdenture using a coping type and an extracoronal magnetic attachment. A mandibular definitive prosthesis was fabricated with a partial denture with an extracoronal magnetic attachment, and the implant abutments were coated under the denture base.

【Objective】

Single-implant overdenture (S-IOD) for edentulous mandible patients can reduce treatment cost and surgical invasiveness, and a relatively high success rate has been reported. In this report, we describe a case of S-IOD using magnetic attachments.

【Summary of the case】

The patient was a 66-year-old partially edentulous woman. In the mandibular arch, the two remaining teeth were the left lateral incisor and canine. Her chief complain was an unstable existing of mandibular denture. After extraction of her remaining teeth, which were difficult to preserve, an implant overdenture was selected. The height and width of residual ridge was possible for two implant overdenture, but for economic reasons and surgical invasion, implant was placed in the midline, and an S-IOD with a magnetic attachment was fabricated.

【Results and Discussion】

After the denture was placed, there was no significant bone resorption around the implant, no detachment of the attachment, no decrease in retentive force, and no fracture of the denture, and the patient`s satisfaction and masticatory function was improved. The application of magnetic attachments to S-IODs may have reduced the lateral pressure on the implants and resulted in a good outcome.

【Introduction】

Many patients complain of discomfort in the palate when wearing maxillary dentures, and in clinical practice, many patients desire a palate-free denture. Palateless dentures have a wider tongue tuft, stabilize the tongue position, secure the airway area, and are expected to improve swallowing, pronunciation, taste, etc., and have long been considered as dentures that are comfortable to wear. This time, we will report that we performed an edentulous maxillary implant overdenture (IOD) using the MACS system and obtained good results.

【Case report】

The patient is a 69-year-old man. He came to our hospital complaining that his upper dentures tended to come off easily, and that he had difficulty chewing and pronouncing. His upper jaw was edentulous and he requested an IOD using an implant. Four implants were placed in the upper jaw, and after a period of unloading, secondary surgery was performed, impressions and occlusal recordings were taken, and a palate IOD was attached using the magnetic attachment of the MACS system.

【Discussion/conclusion】

Problems with mastication and pronunciation could be improved by wearing a stable denture with less discomfort using a palate IOD using a magnetic attachment.

The patient was a 71-year-old partially edentulous patient suffering from masticatory disturbance caused by a reduction of occlusal contacts in posterior regions and severe tooth mobility with severe periodontitis. Treatment dentures were delivered to maintain oral functions and initial periodontal therapy was performed, followed by rehabilitation with maxillary overdenture and mandibular clasp-retained removable partial denture placement as the definitive prosthodontic treatment. By application of magnetic attachments incorporated in an overdenture, the disarranged occlusal plane was corrected and denture stability was achieved. Based on the oral health impact profile (OHIP-14) assessment, the oral health-related quality of life (OHRQoL) of the patient was improved with the prosthodontic treatment.

In this study, we report on the accuracy of matching titanium root copings fabricated using a high-precision laboratory scanner.

The abutment tooth was a preformed epoxy artificial tooth (A50-359, NISSIN). The manufacturing procedure involves scanning a work model using a laboratory scanner (E3, 3Shape), modeling it using design software (Dental System, 3Shape), and then cutting it with a milling machine (GeoMill ARUM 5X, GeoMedi). Five specimens were tested, and the fitting accuracy of the titanium root coping was evaluated using the cement replica method.

The measurement points are the labial margin at point a, the labial cervix at point b, the labial post at point c, the tip of the post at point d, the lingual post at point e, the lingual cervix at point f, and the lingual margin at point g. The average gaps were 46.4±17.8 μm at point a, 59.6±13.6 μm at point b, 31.6±8.9 μm at point c, 145.7±43.8 μm at point d, 46.4±11.2 μm at point e, 92.7±14.3 μm at point f, and 72.1±37.0 μm at point g.

It was suggested that the titanium root coping manufactured using a high-precision laboratory scanner could be applied clinically.

The purpose of this study is to evaluate patient-reported outcomes in Implant-Assisted Removable Partial Denture (IARPD) using short implants and magnetic attachments through an intervention study.

The study recruitted 30 patients with mandibular Kennedy Class I or II free-end edentulous. Implants with a diameter of 4.1mm and a length of 6mm were placed in the free-end edentulous areas to support IARPD. Oral Health Impact Profile-Japanese version (OHIP-J) and a 100mm Visual Analog Scale (VAS) were used to assess oral health-related quality of life (OHRQoL) and patient satisfaction at before surgery (Stage 0), after replacement with healing cap, after replacement with magnetic attachment, 1, 2, and 3 years after implant placement.

OHIP-J and patient satisfaction, significant improvement were observed at 2 and 3 years after implant placement compared to Stage 0. The use of short implants and magnetic attachments in IARPD suggests the potential for long-term maintenance and favorable by patients’ subjective evaluations .

Dental magnetic attachments were approved for use by the Japan National Insurance in September 2022, and their clinical usage may change. Therefore, we investigated the use of the magnetic attachments between September 2022 and August 2023. We investigated the use of the magnetic attachments between September 2022 and August 2023.

71 magnetic dentures were used. The age at application was mostly ≥60 years, confirming that magnetic attachments are often used in elderly patients.

The number of cases covered by insurance remained at approximately 50% of self-payment cases.

Magnetic attachments used per denture was 1–3 (average; 1.92), with a relatively small number being used.

Regarding to Eichner classifications, magnetic dentures were applied to Eicher B2–C2 cases, especially after B4 cases with loss of occlusal support in the molars.

The reasons for the selection of magnetic attachments tended to be poor crown-root ratio and lack of occlusal support, and they tended to be used in cases with poor abutment tooth conditions.

Magnetic attachments are often used for a small number of remaining teeth (1–3 teeth) with poor abutments in elderly patients with insufficient occlusal support because they can reduce harmful lateral forces on abutment teeth.

Dental magnetic attachments are mostly paired combinations of magnetic assembly and keeper or two magnets. A combination of two magnetic assemblies is rare. In the previous study, we investigated characteristics of retentive force when combining two sandwich-type magnetic assemblies and identified several advantages. This study explores the retentive force characteristics of cup-yoke type magnetic assemblies in pairs. We prepared commercially available magnetic assemblies (Physio Magnet 5213) with the magnetization direction reversed and combined the magnetic assemblies with either keeper or with normal magnetic assemblies. The pair was mounted on a measuring device and retentive force experiments conducted as specified in ISO 13017. In addition, we measured the retentive and resistance forces during lateral displacement between two magnetic assemblies. The retentive force of a pair of magnetic assemblies was higher than that of magnetic assembly combined with keeper. There was a decline in retentive force measured upon separation of mating faces. It was more gradual in the case of two magnetic assemblies compared to assembly and keeper. Furthermore, a pair of combined magnetic assemblies generated a large restoring force against displacement. It was established advantageous to combine two magnetic assemblies.