Overdentures with magnetic attachments might experience eccentric movements during oral function potentially causing surface wear on the magnetic attachments. Recently, a thin magnet had been developed. The wear effect of thin magnet on retentive force when using for overdentures has not been investigated. This study evaluated the two types of magnetic attachments provide adequate wear resistance and retentive force for clinical use. A total of 10 pairs of each MT 900 and MTS 700 magnetic attachments (MagneDesign, Japan) were tested. The retentive force was measured 15 times using a universal testing machine (Instron 5544, Instron, USA) before and after 30,000, 60,000 and 90,000 of wear test. A 3mm of gliding movement was performed by using a wearing machine (K655, Tokyo Giken, Japan). The results were statistically evaluated by using One-way ANOVA and post hoc Tukey-Kramer test. (P < 0.05). After 90,000 wear cycles, the MT900 magnet showed progressive decrease of 0.1, 0.2 and 0.3 N at 30,000, 60,000 and 90,000 cycles respectively. In contrast, the MTS700 magnet increased about 0.7N between 0 and 30,000 cycles, consequently the values remained stable through 60,000 and 90,000 cycles. The MT900 exhibited minor surface irregularities whereas the MTS700 experienced complete loss of outer yoke.

This case report describes our establishment of an appropriate OVD for a patient with a decreased OVD to restore the aesthetics and function by the use of magnetic attachments.

As a definitive prosthesis, a maxillary removable overlay denture with coping-type magnetic attachments and a horseshoe plate as the major connector was fabricated , and a mandibular removable partial denture with an extracoronal-type magnetic attachment was also fabricated.

Fourteen years after the denture setting, the definitive prosthesis has been used without serious problems and the magnetic attachment has no clinically significant loss of retention.

Stainless-steel multistranded wires are widely used as fixed lingual retainers; however, their magnetization and the potential to induce magnetic resonance imaging (MRI) artifacts are not widely recognized. Although clinically relevant, quantitative evaluation of magnetization in orthodontic retainer wires remains limited.

This study aimed to characterize the magnetization of stainless-steel multistranded retainer wires commonly used for fixed lingual retention (0.0175-inch and 0.0195-inch). Magnetic attraction was measured using a retention force testing system compliant with ISO 13017:2020, with a dental magnetic attachment serving as a stable magnetic field source. To assess the influence of clinical manipulation, measurements were performed under four conditions: no bending, one-point bending, two-point bending, and two-point bending followed by straightening.

Both wire types exhibited measurable magnetization, and the intact wires already demonstrated quantifiable magnetic attraction. No significant differences were found among the four bending conditions, indicating that the magnitude of magnetic attraction remained comparable regardless of bending manipulation. Taken together, these findings demonstrate that stainless-steel multistranded retainer wires inherently possess magnetization and the routine clinical bending does not substantially modify their magnetic state. This study provides quantitative insight into the magnetic characteristics of orthodontic retainers and may support clinical considerations related to MRI artifacts.

If an implant placed at another dental clinic remains and a superstructure needs to be refabricated, the implant manufacturer will be identified and the necessary parts will be used. In this case, the manufacturer and type of the remaining implant could not be identified, making it difficult to select the abutments and attachments to use. Therefore, custom magnetic attachments were used to place on the remaining implants, and an implant overdenture (IOD) was fabricated, resulting in high patient satisfaction and favorable results.

The patient was a 67-year-old woman who visited our clinic complaining of a fractured maxillary implant-fixed superstructure treated overseas. At the first visit, it was difficult to identify the manufacturer and type of the implant because the shape of the implant was different from implants available in Japan. The only information we had to rely on was the shape of the implant platform and panoramic X-ray images. We fabricated a custom magnetic attachment using the available multi-unit abutments from other manufacturers. Although the IOD was firstly fabricated to cover the entire palate, the palatal plate was removed to modify the IOD into a horseshoe-shaped one because sufficient retention was achieved by the magnetic attachment.