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Biomedical subjects

I Aviv

Publications and source records attributed to I Aviv.

At least 19 recordsLinked to original sources
PubMed1999

Further aspects of design for distal extension removable partial dentures based on the Kennedy classification.

A supplement to the Kennedy classification of partially edentulous arches for restoration with removable partial dentures has been suggested. Factors affecting denture design relating to the position of the abutment teeth, the symmetry of the edentulous distal extensions, the arch form and the cross-sectional shape of the residual ridges have been discussed and classified. An understanding of the movement of the denture bases in relation to the influence of these factors makes for a rational approach to removable partial denture design and the treatment of complications observed clinically in removable partial denture wearers.

Alveolar Process↗
PubMed1992

The cantilever fixed partial denture--a literature review.

The cantilever fixed partial denture (FPD) is a restoration with one or more abutments at one end and unsupported at the other end. Forces transmitted through the cantilevered pontics can cause tilting and rotational movements of the abutments. In a cross-arch unilateral cantilever FPD, the distal cantilevered unit is subjected to comparatively less force than the contralateral posterior abutment. The unilateral lack of terminal abutments causes lateral bending forces activate peripheral inhibitory feedback reactions from the periodontal and/or temporomandibular mechanoreceptors. The greatest strain in distal cantilevered FPDs is recorded mesial to the most distal retainer because most fractures occur in this location. To improve the prognosis of the FPD cantilever, the number of abutments should be increased and the number of pontics decreased. The abutment teeth need long roots and acceptable alveolar support. Prepared abutments require adequate length and parallel axial walls. An equilibrated and harmonious occlusion is necessary, as well as exemplary oral hygiene. A cantilevered FPD with adequate periodontal support can replace any tooth in the dental arch, but is especially useful as an alternative to a removable partial denture. The cantilevered FPD requires at least two abutment teeth. The only documented exception permitting a single abutment is the replacement of a maxillary lateral incisor with the canine as an abutment. An alternative to the cantilevered FPD is the osseointegrated implant. As osseointegrated implants become more popular, the need for the tooth-supported cantilevered FPD may decline, but it will remain an alternative treatment modality.

Biomechanical Phenomena↗
PubMed1991

Factors affecting displacement of free-end saddle removable partial dentures.

Tissueward movement of the free-end saddle of a removable partial denture during function takes place around the most distal fulcrum created by the most mesial rests. Displacement because of sticky foods takes place around the fulcrum created by the most distal rests. These and other factors affecting displacement of the free-end saddle removable partial dentures are discussed, and designs intended to increase retention are presented. The forces applied to the most anterior and posterior axes of rotation can be calculated mathematically to reveal the hazards of a too-short lever arm in combination with a strong retentive clasp system.

Dental Stress Analysis↗
PubMed1990

RLS--the lingually retained clasp assembly for distal extension removable partial dentures.

The design of clasp for a distal extension removable partial denture that helps preserve both the abutment teeth and the tissues of the edentulous ridge is described. The clasp assembly takes advantage of surveyed lingual undercuts to provide support, retention, and stability. It consists of a mesio-occlusal rest, a distolingual L-bar direct retainer that is located on the abutment tooth adjacent to the residual ridge, and a distobuccal stabilizer (RLS).

Denture Design↗
PubMed1989

Rigidity of major connectors when subjected to bending and torsion forces.

Rigidity tests were performed on maxillary major connectors of different designs and mandibular major connectors of the lingual bar-type with different cross-sectional shapes and thicknesses. Each major connector was clamped on one side while the other side was subjected to bending, torsion, and bending under torsion forces. Deformation was measured with a micrometer microscope. The most rigid maxillary major connector was the design incorporating the anterior-posterior palatal bar. The most flexible was the U-shaped palatal bar. The full pear-shaped lingual bar (4 x 4 mm) was the most rigid of the major connectors. Among the more conventional lingual bars, the semielliptical bar (3.75 X 1.75 mm) was the most rigid, and the narrow semielliptical bar (4 x 1.5 mm) was the most flexible.

Chromium Alloys↗
PubMed1989

A rapid dowel core construction technique.

The use of composite resins for dowel cementation and core construction is well established. A short, easy, time-saving method is proposed for simultaneous dowel cementation and core fabrication using a composite core construction material.

Composite Resins↗
PubMed1989

Photoelastic analysis of stress transfer by endodontically treated teeth to the supporting structure using different restorative techniques.

A photoelastic model was used to examine the influence of different types of restorations placed following endodontic therapy, emphasizing the way in which forces applied to the occlusal surface were dispersed to the supporting structures of the teeth. Stresses were photographed in the polarized light field. Findings indicate that distribution and patterns of stresses vary depending on the direction of the loads and the nature of the involved restorative procedures.

Bite Force↗
PubMed1989

An analysis of rotational movement of asymmetrical distal-extension removable partial dentures.

An axis of rotation is created through the most distally placed occlusal rests when a distal-extension removable partial denture is loaded. If the residual ridges are of unequal lengths, this axis of rotation may not be perpendicular to the residual ridges. The resultant movement of asymmetric denture bases and their effect on the tissues are discussed. Movement of I-bar retainers located on the mesiobuccal aspect of asymmetrical abutment teeth may torque the abutment teeth as the denture base moves tissueward. Use of L-shaped direct retainers on the distobuccal surveyed undercut will create a more favorable class II lever effect on the abutment tooth.

Dental Abutments↗
PubMed1988

A modified direct retainer design for distal-extension removable partial dentures.

The rationale for designing a direct retainer for a distal-extension removable partial denture is described. The advantages of an L-bar clasp arm over the I-bar clasp arm are discussed. The retentive surface of an abutment tooth is divided into three zones according to the clasp tip movement and the importance of placing the retentive tip in the zone of vertical movement is emphasized.

Dental Abutments↗