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Biomedical subjects

M C Mensor

Publications and source records attributed to M C Mensor.

At least 19 recordsLinked to original sources
PubMed1999

Compliant Keeper system replication of the periodontal ligament protective damping function for implants: part II.

STATEMENT OF PROBLEM: There are numerous articles regarding implant overloading, interfacial integrity and component failure. A significant amount of literature review supports the concept of the progressive loading and damping, and it should be addressed. PURPOSE: This study was designed to correlate durometer measurements of the elastomeric test materials and actual Periotest values (PTV) of the test materials as preloaded sleeve rings in Compliant Keeper abutments to support the Compliant Keeper as a viable implant damping system. MATERIAL AND METHODS: A 4-unit fixed-removable implant-supported partial denture was the test model. Sleeve ring combinations replaced "O" rings and 220 Periotest measurements were graphically recorded, then analyzed by least square of means, 2-way analysis of variance, and a Tukey test. RESULTS: There was a correlation between durometer measurements and PTVs of sleeve rings. Finite movement was measured accurately with the Periotest (P =. 0001) so that Compliant Keeper systems can be programmed to match the movement of another implant abutment, because they might be able to match the PTV of a natural abutment. CONCLUSIONS: Significant differences exist between the "O" rings and sleeve rings. The sleeve ring, as a controllable damping element, enables the Compliant Keeper system to provide progressive loading and damping for implant-supported prostheses.

Analysis of Variance↗
PubMed1998

Compliant Keeper system replication of the periodontal ligament protective damping function for implants: Part I.

STATEMENT OF PROBLEM: Numerous reports and studies have been published relative to implant overloading, interfacial integrity, and component failure. A significant amount of literature review supports the concept of progressive loading and damping and that it should be addressed. PURPOSE: This article reviews the literature on load reduction and uses the Periotest instrument to evaluate the viscoelastic materials of the Compliant Keeper implant damping system in vitro. MATERIAL AND METHODS: The test model was a vice-mounted resin mandible replica with a 4-unit fixed-removable implant-supported Compliant Keeper partial denture. Pontics were both cantilevered and bounded. Three 13-gauge measurement extensions were located facially on the gingival, middle, and occlusal thirds of each abutment and pontic for 312 Periotest measurements of O-ring combinations with a titanium O-ring as the null control. Measurements were averaged and recorded. RESULTS: Because the Periotest can measure finite movement below Miller Class I, Periotest values were obtained for O-rings so that they could be used to program a Compliant Keeper system to match the Periotest values of another implant body. CONCLUSIONS: Significant loading differences were found with the O-rings. The O-rings controlled the damping element so they enabled the Compliant Keeper system to provide damping and progressive loading for implant-supported prostheses.

Biomechanical Phenomena↗
PubMed1990

Removable partial overdentures with mechanical (precision) attachments.

Mechanical attachments for overdentures have been available in various forms for over a century. The explosive interest in osseointegration and the effort on the part of the profession to avoid the complete denture as a treatment modality has stirred the interest in positive retentive elements for overdentures represented by the mechanical stud and bar attachments. The cited references provide a resource as a trouble-free guide in the selection and use of the various stud and bar attachment systems. The clinical examples show a pattern of application not generally discussed by the manufacturers, illustrating the simplicity of use with the options for all attachments including magnets. The discussion on magnets comes from 9 years of clinical experience. Rare earth magnets provide excellent adjunct retention, and their assembly follows the same protocol and complexity as stud attachment systems. All magnets, at the present state of the art, have a corrosion potential with the exception of the Laser Sealed Units (Golden Dental, Golden, CO). Finally, the mechanics of the attachment overdenture serves as an excellent training field for the osseointegrated prosthesis, be it the classic Brånemark (Nobelpharma USA, Chicago, IL) restorative or the implant overdenture concept.

Adult↗
PubMed1978

Attachment fixation of the overdenture: part II.

Many attachment systems of the bar or stud type increase the stability of an overdenture. When selecting an attachment it is essential to consider the skill of the dentist-laboratory team as well as the dexterity of the patient and to use the easiest system that will still improve stabilization. Generally simplicity in design, ease of maintenance, and minimum leverage should be paramount considerations in selection. Use of a guide such as the EM Gauge and of the EM Attachment Selector significantly reduces the confusion in selecting attachments and increases the working armamentarium for stabilizing an overdenture.

Denture Design↗
PubMed1977

Attachment fixation for overdentures. Part I.

Scientific evidence of both constructive and destructive movements of teeth has influenced the design and selection of attachments for overdentures. Dowel designs that would be acceptable for normal copings must be reconsidered in view of the mechanical effectiveness of parallel-walled dowels and screws. Coping designs for attachment overdentures must provide retention, resistance to rotation, and bulk when joined with the dowel and attachment, without negating the advantage of the reduced crown-root ratio. Splinting with a bar-type attachment (1) has advantages over splinting with a stud-type attachment that outweigh the disadvantages of bulk and (2) provides ease of replacement when one of several remaining teeth is excessively mobile. Part II will consider the various types of bar, stud, and auxillary attachments for the overdenture.

Dental Abutments↗