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Biomedical subjects

D Dietschi

Publications and source records attributed to D Dietschi.

At least 19 recordsLinked to original sources
PubMed2001

Layering concepts in anterior composite restorations.

SUMMARY: With increasing patient demands for esthetic dentition, composite resin restorations enjoy great popularity due to excellent esthetics, acceptable longevity, and relatively low costs. Shading concepts used by manufacturers, however, may be confusing to many clinicians. PURPOSE: To review and describe the current main shading concepts, evaluate their potential for creating natural esthetics, and provide guidelines for application.

Adult↗
PubMed2000

Treatment of traumatic injuries in the front teeth: restorative aspects in crown fractures.

Crown fractures are the most common form of traumatic dental injuries encountered in permanent dentition. Restorative treatment modalities incorporate adhesive materials to effectively maintain function and aesthetics. While uncomplicated injuries of the enamel and/or dentin can be treated solely with adhesive procedures, complicated trauma that involves pulp exposure requires the incorporation of a multidisciplinary treatment approach. Fragment reattachment is facilitated by the utilization of bonding agents that enhance retention and aesthetics. This article discusses the application of provisional and permanent restorative options for the treatment of complications following traumatic injuries.

Adhesives↗
PubMed2000

Treatment of luxation traumatic injuries: definition and classification in the literature.

Luxation traumatic injuries affect the hard tissues and may involve periodontal tissues in severe cases. Periodontal healing must be considered during treatment of traumatic injuries that result in total luxation of the teeth. Pulpal healing is essential for the endodontic prognosis of a reimplanted tooth, as well as for its periodontal healing. Luxation injuries can be further classified as intrusive, extrusive, and/or lateral; this categorization further facilitates the mode of splinting and repositioning utilized during treatment. This article reviews various types of dentoalveolar traumatic injuries and discusses commonly incorporated treatment modalities.

Alveolar Process↗
PubMed1999

Evaluation of the marginal and internal adaptation of different ceramic and composite inlay systems after an in vitro fatigue test.

PURPOSE: The aim of this in vitro trial was to evaluate and compare the external and internal adaptation of Class II composite and ceramic inlays with scanning electron microscopy after mechanical loading and thermal cycling (fatigue). MATERIALS AND METHODS: Standardized cavities were prepared on human third molars with margins extending proximally 1 mm above or below the cemento-enamel junction (CEJ). A fine hybrid composite (Tetric), a hydrothermal glass (Ducera LFC), and a sintered spinell ceramic (In-Ceram) were used to fabricate the restorations. Combinations of Syntac classic--Variolink, ED primer--Panavia and Scotchbond MP--Variolink were used for cementation. RESULTS: For marginal adaptation in enamel, percentages of continuity varied from 85.4% to 99.6% and 85.1% to 98.2% for mesial and distal sites, respectively. Marginal adaptation in dentin showed continuity percentages varying from 63.6% (In-Ceram-Panavia) to 96.1% (Ducera LFC-Panavia). As regards internal adaptation, overall interface results varied from 32.1% (Tetric-Variolink) to 87.3% (Ducera LFC-Panavia). Gingival enamel showed the higher proportions of continuity (94.0%, all group-pooled data) compared to dentin locations (46.0% occlusally to 60.1% in gingival dentin). In all groups, debonding occurred mainly within the dentin--restoration interface and also, but to a lesser extent, between In-Ceram ceramic and both luting composites. When it occurred, adhesive failure to dentin consistently took place at or close to the hybrid layer surface. CONCLUSION: Despite important differences in their physical properties, no difference could be found under the present experimental conditions between Class II composite and ceramic inlays in terms of their marginal and internal adaptation.

Aluminum Oxide↗
PubMed1998

In vitro evaluation of marginal and internal adaptation of class II resin composite restorations after thermal and occlusal stressing.

The aim of this in vitro trial was to evaluate the external and internal adaptation of class II composite restorations to tooth structure by means of replica scanning electron microscope (SEM) observation. Standard MOD preparations were cut in human extracted teeth with margins located above and below the cementoenamel junction. Cavities were restored with either a direct multilayered technique, inlays (using conventional or dual DBA application) or prepolymerized composite inserts, using similar restorative material (Syntac, Variolink and Tetric). Evaluations were performed after mechanical and thermocycling. For the marginal adaptation in enamel, the bevelled margins of the direct group resulted in higher percentages of "continuity" (92.5% mesially and 94.6% distally), while the "marginal tooth fracture" was the most commonly found defect in groups with a butt preparation (up to 29.4%, with inserts). For the marginal adaptation in dentin, "continuity" percentages varied from 59% (inlay) to 87.9% (insert). As regards the internal adaptation, results for the whole dentin interface varied from 43.1% (inlay) to 63.9% (inlay with dual bonding) of "continuity". No regional difference in internal adaptation was found between the different preparation areas, except between gingival dentin and gingival enamel (44.9% vs. 80.7% of continuity, all group pooled data). Debonding occurred only at the dentin-restoration interface and consistently took place at the top of the hybrid layer. In the present experimental conditions, the inlay or insert techniques, which make use of the Dual bonding concept, proved to have the best potential to maintain the integrity of dentin-restoration interface.

Composite Resins↗
PubMed1998

Esthetic single-tooth replacement with implants: a team approach.

The range of indications for implant-borne prostheses in partially edentulous patients has expanded in recent years as a consequence of advances in regenerative techniques for bone and soft tissues. The esthetic demands of both patients and dentists have risen in parallel with these advances. Esthetic compromises in prostheses have become increasingly less tolerable, particularly in the anterior region of the maxilla. If the presenting situation is less than optimal, extensive preprosthetic measures may be required to prepare local tissues for acceptance of esthetically and functionally adequate prostheses. Particularly in difficult situations, collaboration by a team is recommended. The exchange of ideas and experience among specialists should begin as early as the treatment planning stage and extend over the entire course of therapy. The objective should be defined and the various steps of treatment should be coordinated with participation from all team members.

Adolescent↗
PubMed1998

Principles of proximal cavity preparation and finishing with ultrasonic diamond tips.

Conventional treatment of proximal cavities can result in significant damage to the adjacent dentition. This paper describes a recently developed technique of proximal cavity preparation and finishing by use of selectively diamond-coated, ultrasonically driven instruments. By using these instruments for composite, compomer, ceramic, amalgam, and even gold restorations, the inadvertent damage to neighboring teeth is completely avoided. This article demonstrates the effective utilization of the diamond-tipped ultrasonic instruments for the preparation of primary lesions and the replacement of existing restorations.

Dental Caries↗
PubMed1997

Current restorative modalities for young patients with missing anterior teeth.

The early loss of permanent teeth following trauma or congenital aplasia may be corrected by orthodontic or prosthetic means, sometimes combined with implant therapy. The orthodontic solution results usually in different anatomic, functional, and esthetic problems. Prosthetic and implant procedures, on the other hand, are very demanding and require long-term maintenance. Considering these limitations, a comprehensive diagnostic and treatment plan is mandatory to achieve the most satisfactory clinical result. Modern restorative modalities, such as recontouring, bleaching, and resin composite bonding, may improve the final clinical result after orthodontic space closure. In more difficult situations, veneers and crowns may also be indicated.

Adolescent↗
PubMed1997

Anatomical applications of a new direct Ceromer.

Composite resin materials have become the basic restorative materials of the modern aesthetics-oriented practice. However, the application of composite resin in posterior teeth remains a challenge as a result of its handling characteristics and chairside stratification. New ceramic optimized polymers (ceromers), such as Tetric Ceram (Ivoclar Vivadent, Amherst, NY), now offer versatility and improved handling properties in response to increasing clinical demand for producing high-quality natural restorations. With a well-designed instrumentation, the work of the clinician may be greatly facilitated. This article evaluates the selection and utilization of a direct ceromer material for posterior restorations and presents a predictable method to achieve aesthetic restorations.

Ceramics↗
PubMed1996

Evaluation of post and cores in the laboratory: rationale for developing a fatigue test and preliminary results.

Prosthetic treatment failures related to the biomechanical deficiencies of post and cores still represent a problem of clinical significance. To overcome the difficulties of clinical studies, numerous in vitro methods were developed to address specific properties of post-and-core restorations. Most of them, however, were based on an oversimplified mechanical testing of the restored tooth. Experience proved that the fatigue of restorative materials was a primordial factor in clinical failures. Therefore, special devices were built that stimulate the physiological masticatory cycle. Tests performed with adhesive post-and-core systems seem to indicate that materials placed in the tooth should have physical properties as close as possible to those of natural tissues. New carbon-epoxy posts appear to offer a promising solution for restoring the endodontically treated tooth.

Biomechanical Phenomena↗
PubMed1996

Esthetic restorations for posterior teeth: practical and clinical considerations.

The current abundance of posterior esthetic restorative materials and techniques may be confusing. This paper describes a simple and logical global concept that assists clinicians in choosing the appropriate therapeutic modality according to well-defined clinical criteria. Practical considerations about cavity preparation, base-lining, filling, luting, and finishing procedures are reviewed.

Bicuspid↗
PubMed1996

Current developments in composite materials and techniques.

General reduction of dental caries and patient interest in dental aesthetics have resulted in the development of new restorative materials and techniques. Composite materials and adhesive techniques have become the foundation of modern restorative dentistry. Mechanical performance, wear resistance, and aesthetic potential of composite resins have been significantly improved, and the material is now used in cases ranging from the restoration of initial decays and cosmetic corrections to the veneering in extended prosthetic rehabilitation. Polymerization shrinkage of the resin matrix remains a challenge and still imposes limitations in the application of direct techniques. The learning objective of this article is to review the most significant advances of composite materials and the importance of utilizing the available treatment options with discretion, selecting those which preserve the tooth structure and require the least maintenance.

Composite Resins↗
PubMed1995

Marginal adaptation and seal of direct and indirect Class II composite resin restorations: an in vitro evaluation.

The aim of this in vitro study was to evaluate the marginal adaptation and seal of posterior composite resin restorations made with direct (three-sited multilayering) or indirect (extraoral inlay) techniques. The influence on the marginal quality of the cervical finishing design (butt or beveled) and residual enamel height (0.5, 1.0, and 1.5 mm up to the cementoenamel junction) was also evaluated. This trial was performed on sound, freshly extracted human molars. When residual enamel was less than 1.0 mm in height or 0.5 mm in thickness, indirect restoration resulted in superior marginal quality. For preparations with sufficient residual enamel height (greater than 1.0 mm), beveling of gingival margins appeared mandatory for good adaptation of direct restorations and beneficial to the adaptation of indirect restorations. Residual gingival enamel height and thickness demonstrated an influence on marginal quality only in indirect restorations with butt margins.

Acrylic Resins↗