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Magnetic Attachments (magnetic + attachment)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Mechanical Properties of Magnetic Attachments for Removable Prostheses on Teeth and Implants

JOURNAL OF PROSTHODONTICS, Issue 8 2008
Arne F. Boeckler DMD
Abstract Purpose: Magnetic attachments on teeth and implants may be used to improve stability, support, and retention of removable prostheses. Various forms of magnetic attachments are available, divided according to the design, the mechanical properties of the attachments, and the clinical indication. Recently developed attachment systems are small and promise improved retentive capacity, while existing magnetic attachments continue to be technologically modified and improved. This investigation reviewed and compared maximum retentive forces and characteristic curves for magnetic attachments indicated for use as root anchors and on implants. Materials and Methods: Twenty-four samarium-cobalt (SmCo) and neodym-iron-boron (NeFeB) magnetic attachments (12 tooth- and 12 implant-borne) were evaluated. Specimens were delivered by the manufacturers or fabricated according to their instructions. Five magnet pairs of each product and each combination were tested 10 times in a calibrated universal testing machine using a nonmagnetic test device (s = 40 mm, v = 20 mm/min). Results were recorded electronically and compared to manufacturers' details. Results: Maximum retentive forces for root keepers ranged from 1.4 to 6.6 N. Maximum retentive forces for magnetic attachments on implants ranged from 0.7 to 5.8 N. After a distance of 0.1 mm, a complete reversed distribution of the different systems became obvious. The retentive force provided by the manufacturer was achieved in one implant abutment, with retentive force (as compared to those provided by the manufacturers) for root keepers ranging between 42.5% and 92.9% and for implant abutments between 43.0% and 99.4%. Conclusion: There were differences between magnetic attachments for both the initial retentive capabilities and the characteristic curves. Recently introduced products provided relatively high initial retentive forces despite their small size. The measured retentive forces and the manufacturer's information differed in the majority of magnetic systems evaluated. [source]

Adhesive bonding of titanium nitride-plated stainless steel for magnetic attachments

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2001
Yohsuke Taira
The purpose of this study was to evaluate adhesive bonding of resin to titanium nitride ion-plated stainless steel in order for magnetic attachments to survive in the oral environment. Two primers, Cesead II Opaque Primer (CPII) and Metal Primer II (MPII), and one bonding agent, Super-Bond C&B (SB), were used. The surfaces of stainless steel disks were ground and then plated with titanium nitride. After the primer and SB resin were applied, a self-curing resin was bonded to the metal surfaces. Shear bond strengths were determined after 24 h of water storage and after 2,000 thermocycles. Titanium nitride ion-plated stainless steel showed bond strength comparable to the non-plated material. After thermocycling, all specimens of the group no primer/no SB were debonded. The bond strengths of groups CPII/no SB, MPII/no SB and no primer/SB were significantly lower bond strengths than groups CPII/SB and MPII/SB. An appropriate combination of primer and bonding agent should be selected when bonding a magnetic attachment to the denture base. [source]

Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture,

JOURNAL OF ORAL REHABILITATION, Issue 10 2004
T. Gonda
summary, Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments. [source]

Adhesive bonding of titanium nitride-plated stainless steel for magnetic attachments

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2001
Yohsuke Taira
The purpose of this study was to evaluate adhesive bonding of resin to titanium nitride ion-plated stainless steel in order for magnetic attachments to survive in the oral environment. Two primers, Cesead II Opaque Primer (CPII) and Metal Primer II (MPII), and one bonding agent, Super-Bond C&B (SB), were used. The surfaces of stainless steel disks were ground and then plated with titanium nitride. After the primer and SB resin were applied, a self-curing resin was bonded to the metal surfaces. Shear bond strengths were determined after 24 h of water storage and after 2,000 thermocycles. Titanium nitride ion-plated stainless steel showed bond strength comparable to the non-plated material. After thermocycling, all specimens of the group no primer/no SB were debonded. The bond strengths of groups CPII/no SB, MPII/no SB and no primer/SB were significantly lower bond strengths than groups CPII/SB and MPII/SB. An appropriate combination of primer and bonding agent should be selected when bonding a magnetic attachment to the denture base. [source]

Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture,

JOURNAL OF ORAL REHABILITATION, Issue 10 2004
T. Gonda
summary, Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments. [source]

Corrosion of Dental Magnet Attachments for Removable Prostheses on Teeth and Implants

JOURNAL OF PROSTHODONTICS, Issue 4 2009
Arne F. Boeckler DMD, Dr Med Dent
Abstract Purpose: For a long time, the use of magnets for the anchorage of dental prostheses failed due to lack of biocompatibility and the magnets' high susceptibility to corrosion in the mouth. These facts make encapsulation of the magnetic alloy with a corrosion-resistant, tight, and functionally firm sealing necessary. Due to different products and analysis methods, it is not feasible to compare the findings for contemporary products with the sparse and rather old test results in the literature. Therefore, the aim of this study was the standardized control and the comparison of the corrosion behavior of modern magnetic attachments for use on teeth and dental implants. Materials and Methods: Thirty-seven components of magnetic attachments on implants and natural teeth from different alloys (NdFeB, SmCo, Ti, CrMoMnTiFe, etc.) as delivered by the manufacturers or fabricated according to their instructions were examined for their corrosion behavior using the statical immersion analysis (ISO 10271:2001). Four specimens of every product with the same design were used. An uncased SmCo magnet served as control. Analyses after 1, 4, 7, and 28 days of the storage in corrosion solution were made. The eluate was examined quantitatively on the alloy components of the respective component with the help of optical emission spectrometry (,g/cm2). The results were compared to the requirements of ISO standard 22674:2006. In addition, existing corrosion products were also defined in the solution after 28 days. The results were analyzed descriptively and statistically to determine possible significant differences (t -test and Mann-Whitney-Wilcoxon rank-sums test; p < 0.05). Results: Dissolved metal ions could be found on all tested products. The release after 1 and 4 days was different for all specimens. In the group of implant abutments, the highest ion release after 7 days was found (all measurements ,g/cm2): Fe (13.94, Magfit-IP-IDN dome type), Pd (1.53, Medical-anchor), Cr (1.32, Magfit-IP-IDN dome type), Ti (1.09, Magfit-IP-IDN abutment), Co (0.81, Medical-anchor), and B (0.6, Magfit-IP-IDN dome type). After 28 days, the analyzed ion release increased irregularly: Fe (173.58, Magfit-IP-IDN dome type), Pd (44.17, Medical-anchor), Cr (2.02, Magfit-IP-IDN dome type), Ti (2.11, Magfit-IP-IDN abutment), Co (26.13, Medical-anchor), B (1.77, Magfit-IP-IDN dome type), and Nd (79.18, Magfit-IP-IDN dome type). In the group of magnetic systems on natural teeth, the highest ion release after 7 days was found for Fe (4.81, Magfit DX 800 keeper), Cr (1.18, Magfit DX 800 keeper), Pd (0.21, Direct System Keeper), Ni (0.18, WR-Magnet S3 small), Co (0.12, Direct System Keeper), and Ti (0.09, Magna Cap , Mini). After 28 days, the analyzed ion release increased non-uniformly: Fe (31.92, Magfit DX 800 Keeper), Cr (6.65, Magfit DX 800 Keeper), Pd (18.19, Direct System Keeper), Ni (0.61, WR-Magnet S3 small), Co (10.94, Direct System Keeper), Ti (0.83, Magna Cap , Mini), and Pd (2.78, EFM Alloy). In contrast, the uncased control magnet showed an exponential release after 7 days of Sm ions (55.06) and Co-ions (86.83), after 28 days of Sm ions (603.91) and Co ions (950.56). The release of corrosion products of all tested products stayed significantly under the limit of 200 ,g/cm2 (ISO 22674:2006). In contrast, the non-encapsulated control magnet exceeded that limit significantly. Conclusion: The analysis of the corrosion behavior of modern magnetic attachments for use on teeth and dental implants according to ISO 10271:2001 showed that metal ions had dissolved on all specimens. In the case of one product, the magnet corroded. For this product, an improvement of the capsulation would be desirable. None of the products reached the limit specified in ISO 22674:2006. All products seem to be suitable for dental application. Further studies in regard to the specific biocompatibility and possible cytotoxic effects on mucosa and tissue would be desirable. [source]

Mechanical Properties of Magnetic Attachments for Removable Prostheses on Teeth and Implants

JOURNAL OF PROSTHODONTICS, Issue 8 2008
Arne F. Boeckler DMD
Abstract Purpose: Magnetic attachments on teeth and implants may be used to improve stability, support, and retention of removable prostheses. Various forms of magnetic attachments are available, divided according to the design, the mechanical properties of the attachments, and the clinical indication. Recently developed attachment systems are small and promise improved retentive capacity, while existing magnetic attachments continue to be technologically modified and improved. This investigation reviewed and compared maximum retentive forces and characteristic curves for magnetic attachments indicated for use as root anchors and on implants. Materials and Methods: Twenty-four samarium-cobalt (SmCo) and neodym-iron-boron (NeFeB) magnetic attachments (12 tooth- and 12 implant-borne) were evaluated. Specimens were delivered by the manufacturers or fabricated according to their instructions. Five magnet pairs of each product and each combination were tested 10 times in a calibrated universal testing machine using a nonmagnetic test device (s = 40 mm, v = 20 mm/min). Results were recorded electronically and compared to manufacturers' details. Results: Maximum retentive forces for root keepers ranged from 1.4 to 6.6 N. Maximum retentive forces for magnetic attachments on implants ranged from 0.7 to 5.8 N. After a distance of 0.1 mm, a complete reversed distribution of the different systems became obvious. The retentive force provided by the manufacturer was achieved in one implant abutment, with retentive force (as compared to those provided by the manufacturers) for root keepers ranging between 42.5% and 92.9% and for implant abutments between 43.0% and 99.4%. Conclusion: There were differences between magnetic attachments for both the initial retentive capabilities and the characteristic curves. Recently introduced products provided relatively high initial retentive forces despite their small size. The measured retentive forces and the manufacturer's information differed in the majority of magnetic systems evaluated. [source]