[EO-17] Contemporary Magnetic Removable Partial Denture System Utilizing Ultra-Thin Magnetic Attachment
[Abstract]
[Objective]
Recently, magnetic attachment with high performance has been developing1). This study aimed to evaluate the feasibility of a magnetic removable partial denture without denture base, so-called “magnetic removable bridge“(MRB), utilizing a novel ultra-thin magnetic attachment (UTMA).
[Method]
The study was performed on titanium master models (prepared lower 1st premolar and 2nd molar). Inner crowns (IC) (h: 4 mm; 4 degree taper) and MRB were custom-designed using CAD software and fabricated using zirconia (Katana HT, Kuraray Noritake Dental, Tokyo, Japan). As a retentive component, a 4 mm diameter UTMA system (thickness: magnet assembly (MA) = 0.6 mm; keeper (KP) = 0.4 mm) (Magteeth MTs600, Magnedesign, Aichi, Japan) was fixed into the IC and MRB using a dual-cure resin cement (Panavia V5, Kuraray Noritake Dental, Tokyo, Japan). 100 N load and insertion-removal cycles were applied for 10,000 times. The retentive force, surface condition and MRB stability were evaluated at baseline and after load cycles. Statistical analysis was performed using paired t-test (α=.05).
[Results and Discussion]
MRB mean retentive force was (6.86 ± 0.63 N) and did not change significantly following load cycles (6.66 ± 0.79 N). When receiving occlusal loads, the MRB was stable. Little deformation was found on the MA, keeper, IC, and MRB surfaces following the load tests. MRB utilizing UTMAs possesses favorable retention, stability, and durability. Previously, higher MA and KP thicknesses were reported to contribute to a higher retentive force. In contrast, UTMA provides sufficient retention and stability despite possessing around 50% less thickness than the currently available dental magnets (1.2 mm or more)2). It met the satisfactory retentive force of dental prostheses. With the advantage of its thin structure, UTMA can overcome the limitations of conventional magnetic attachments, especially for limited occlusal clearance. Moreover, it will expand the range of applications for UTMA like MRB.
[References]
1) Putra Wigianto AY, Ishida Y, Ichikawa T, et al. Novel Magnetic Attachment System Manufactured Using High-Frequency Heat Treatment and Stamp Technique: Introduction and Basic Performance. Dent J 2022; 10, 75.
2) Tanaka Y, Aita H, Ichikawa T, et al. New Dental Magnetic Attachment. 1st ed. Tokyo, Japan: Ishiyaku Publishers; 2016.
[Objective]
Recently, magnetic attachment with high performance has been developing1). This study aimed to evaluate the feasibility of a magnetic removable partial denture without denture base, so-called “magnetic removable bridge“(MRB), utilizing a novel ultra-thin magnetic attachment (UTMA).
[Method]
The study was performed on titanium master models (prepared lower 1st premolar and 2nd molar). Inner crowns (IC) (h: 4 mm; 4 degree taper) and MRB were custom-designed using CAD software and fabricated using zirconia (Katana HT, Kuraray Noritake Dental, Tokyo, Japan). As a retentive component, a 4 mm diameter UTMA system (thickness: magnet assembly (MA) = 0.6 mm; keeper (KP) = 0.4 mm) (Magteeth MTs600, Magnedesign, Aichi, Japan) was fixed into the IC and MRB using a dual-cure resin cement (Panavia V5, Kuraray Noritake Dental, Tokyo, Japan). 100 N load and insertion-removal cycles were applied for 10,000 times. The retentive force, surface condition and MRB stability were evaluated at baseline and after load cycles. Statistical analysis was performed using paired t-test (α=.05).
[Results and Discussion]
MRB mean retentive force was (6.86 ± 0.63 N) and did not change significantly following load cycles (6.66 ± 0.79 N). When receiving occlusal loads, the MRB was stable. Little deformation was found on the MA, keeper, IC, and MRB surfaces following the load tests. MRB utilizing UTMAs possesses favorable retention, stability, and durability. Previously, higher MA and KP thicknesses were reported to contribute to a higher retentive force. In contrast, UTMA provides sufficient retention and stability despite possessing around 50% less thickness than the currently available dental magnets (1.2 mm or more)2). It met the satisfactory retentive force of dental prostheses. With the advantage of its thin structure, UTMA can overcome the limitations of conventional magnetic attachments, especially for limited occlusal clearance. Moreover, it will expand the range of applications for UTMA like MRB.
[References]
1) Putra Wigianto AY, Ishida Y, Ichikawa T, et al. Novel Magnetic Attachment System Manufactured Using High-Frequency Heat Treatment and Stamp Technique: Introduction and Basic Performance. Dent J 2022; 10, 75.
2) Tanaka Y, Aita H, Ichikawa T, et al. New Dental Magnetic Attachment. 1st ed. Tokyo, Japan: Ishiyaku Publishers; 2016.