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Biomedical subjects

U Belser

Publications and source records attributed to U Belser.

At least 19 recordsLinked to original sources
PubMed2002

A nonlinear elastic model of the periodontal ligament and its numerical calibration for the study of tooth mobility.

A large strain nonlinear elastic isotropic "split" law is proposed for modeling the behaviour of the periodontal ligament. This law allows for a better description of the stiffening response of this tissue and, concomitantly, for a more accurate calibration of its elastic properties. Indeed, fine finite element simulations of an upper human incisor attached to its surrounding alveolar bone by an intermediate layer of ligament were run using that "split" law for the ligament. A good correlation was established with available experimental data on such a tooth under axial loading. Values of 0.010-0.031 MPa for the initial Young's modulus and of 0.45-0.495 for Poisson's ratio were determined. A sensitivity analysis of the results with respect to material and numerical parameters of the model was also carried out. Finally, a comparison of the simulation results using this "split" law with standard ones obtained with the linear elastic law, shows a significant improvement.

Animals↗
PubMed2000

Prosthodontic considerations.

The prosthodontic section of the 1997 ITI Consensus Conference in Vitznau, Switzerland, examined a broad spectrum of issues related to the prosthodontic phase of dental implant therapy. Topics included diagnosis and treatment planning, considerations for the use of ITI prosthodontic components, management of the partially edentulous patient, management of the edentulous patient, implant occlusion, and the use of narrow- and wide-body implants. The management of partially and totally edentulous patients will be discussed in separate papers. This paper is written so that each major consensus point discussed by the prosthodontic section is the first sentence of a paragraph. The remainder of each paragraph serves as background information or justification for the consensus statement. It should be noted that agreement on all points was reached by voting within the prosthodontic section. Many of the consensus statements were reached unanimously, while some were reached through compromise and split vote. Not all of the points presented here were presented to the plenum session on the final day of the conference.

Cementation↗
PubMed2000

Management of the edentulous patient.

Being edentulous is a handicap, and the main objective of implant placement is to provide support of fixed prostheses or to stabilize complete dentures in the edentulous jaw. Clinical experience and clinical studies have demonstrated the broad application of non-submerged ITI implants in prosthetic therapy in standard sites and in situations of advanced atrophy or substantial loss of tissue. The ITI implant was developed for universal use in partially and completely edentulous patients and for replacement of single missing teeth. The abutment system offers the choice of both removable and fixed prostheses with identical secondary parts. The present article describes the use of ITI implants for prosthodontic rehabilitation in the completely edentulous jaw. Indications and various types of fixed or removable prostheses, alternatives and variations of design are discussed. Prosthetic design is dependent on the number and location of implants, and conversely, the number of implants that can be placed will determine the choice of prosthesis. Treatment planning in general and with respect to individual anatomic-morphologic conditions is described for the upper and lower jaw. Details of clinical procedures with ITI implants related to the specific design of prostheses are presented. Biomechanical aspects of fixation and stabilization of prostheses and aspects of occlusion to be built up complete the overview.

Cementation↗
PubMed1999

The esthetic width in fixed prosthodontics.

With the evolution of adhesive dentistry and the increasing use of porcelain veneers, single-unit crowns generally are restricted to the replacement of pre-existing full-coverage crowns and the restoration of nonvital and/or severely damaged teeth. Porcelain-fused-to-metal restorations are still widely used to generate single-unit crowns and fixed partial dentures. Collarless metal-ceramic restorations represent the most successful evolution among efforts to meet maximum esthetic requirements using porcelain-fused-to-metal restorations. Extended metal frameworks and opaque aluminous ceramic cores are associated with unpleasant optical effects in the soft tissues surrounding such restorations. This problem is particularly evident in the presence of the upper lip, which can generate an "umbrella effect" characterized by gray marginal gingivae and dark interdental papillae. Based on the concept of the biologic width, a systematic approach is proposed for the elaboration of an "esthetic width," including: 1) positioning of preparation margins; 2) reduction of the metal framework; and (c) appropriate marginal design of porcelain-fused-to-metal restorations. Strategic features of pontics and a specific interdental design are suggested to compensate for deficient anatomical features of the soft tissue and the edentulous ridge.

Crowns↗
PubMed1996

The diagnostic template: a key element to the comprehensive esthetic treatment concept.

Provisional restorations represent a key element in the realization of extensive esthetic rehabilitations. In particular, they provide indispensible diagnostic information contribute significantly to adjacent soft tissue conditioning, and ensure the patient's comfort during the intermediate phase of treatment. The-treatment outcome strongly depends on the treatment approach chosen. This article describes a treatment rationale comprising the use of a diagnostic template. This type of work strategy, documented with clinical cases, integrates diagnostic waxups and indirect provisional restorations using simplified and efficient fabrication techniques.

Dental Impression Technique↗
PubMed1993

Localized ridge augmentation using guided bone regeneration. 1. Surgical procedure in the maxilla.

A new surgical technique for localized ridge augmentation prior to the placement of dental implants has been developed. The technique is based on the principle of guided bone regeneration utilizing barrier membranes. In the present article, the currently used surgical procedure is presented through two case reports. In addition, the different aspects of the surgical technique needed to achieve a predictable success are discussed.

Adolescent↗
PubMed1992

[The form of retention and resistance of dental preparations. A review of the literature and the clinical implications].

Generally, the principles of tooth preparation are well established in the majority of textbooks dealing with fixed prosthodontics. However, one specific related aspect, retention and resistance form, still features some elements that might be less known to the clinician. The purpose of the present literature review is to contribute to the classification and current understanding of the terms of retention and resistance. Finally, the resulting clinical implications, focusing primarily on cast full veneer and porcelain-fused-to-metal crowns, will be discussed.

Bite Force↗
PubMed1991

Felodipine-induced gingival hyperplasia: a clinical and histologic study.

This paper reports, for the first time, gingival hyperplasia in a patient treated with felodipine, a drug which belongs to the group of calcium ion antagonists. The observed gingival overgrowth was most significant in the area of interdental papillae of the anterior region of the mouth. The described hyperplastic tissue was characterized by a firm and pale appearance, with a normally stippled pattern. Histopathologically, a conspicuous increase of fibrous connective tissue, as well as an inflammatory infiltrate and hyperplasia of the overlying epithelium were observed. Consequently, the present observation adds another drug to the list of substances capable to induce gingival hyperplasia.

Adult↗