Biomedical subjects
Publications and source records attributed to W H Liebenberg.
Air-abrasive technology offers several advantages over conventional handpieces. Although modern high-speed evacuation systems result in limited powder accumulation, the microabrasive debris continues to be a major concern. This article highlights the need for rubber dam isolation and introduces a makeshift evacuation device fabricated from a plastic soft drink container.
An endodontic file carrier is fabricated from disposable foam fluoride trays glued to a mixing pad. The carrier allows convenient retention and transfer of root canal instruments and is particularly useful when the clinician is utilizing a rotary handpiece canal-shaping technique with hand files and reamers.
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A specifically-formulated, fast-setting die material has made it possible to fabricate and insert indirect resin restorations in one appointment. This case report describes a modification to an existing, newly-released one-appointment resin inlay-onlay technique for the chairside fabrication of indirect composite resin restorations. Using this technique, large occlusal load-bearing extracoronal composite resin restorations can be constructed economically. Although the prognosis for extensive posterior composite resin restorations remains guarded, the modified procedure is a realistic option for financially-compromised patients who request tooth colored restorations.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Intracoronal bleaching of pulpless discolored teeth is a valuable treatment modality currently disregarded by many clinicians because of the potentially disastrous consequence of cervical resorption. A patient-administered, intracoronal carbamide peroxide bleaching technique is described. This modified walking bleach method minimizes the risks because treatment time is reduced to days as opposed to weeks of the original walking bleach protocol; the concentration of the hydrogen peroxide is markedly reduced; and residual hydrogen peroxide is completely eliminated with the use of catalase prior to the definitive restoration.
A case report of a chairside-fabricated indirect resin composite restoration is used to introduce a modification to a newly released one-appointment resin inlay-onlay technique. Fast-setting poly(vinyl siloxane) die material accommodates an articulated working cast within 10 minutes. The technique allows the economical construction of large, occlusal, load-bearing, extracoronal resin composite restorations. The guarded prognosis associated with extensive posterior resin composite restorations is acknowledged; nevertheless this technique remains a realistic option for those financially compromised patients who request tooth-colored restorations.
The objectives of an ideal direct restoration include pulpal health, biocompatibility, occlusal stability, anatomical restitution, marginal perfection, and interproximal integrity. While tooth-colored composites have replaced amalgam as the restorative material of choice for many dental professionals, the utilization of composite materials of two different viscosities has proven effective in increasing strength and adaptation, and facilitating placement of anterior and posterior restorations. Several newly enhanced composite combinations have begun to allay reservations about directly placed tooth-colored restorations. This article classifies the ideal handling characteristics and benefits of a recently introduced, direct Ceromer system (Tetric Flow and Tetric Ceram, Ivoclar Vivadent, Amherst, NY.)
The maxillary incisors occupy an extraordinary position in the dental arch. They set the aesthetic tone, and their influence on the overall well-being of the individual cannot be overemphasized. However, their eruptive pattern and dominance carries a significant risk for trauma, particularly in childhood. More than half of all traumatic dental injuries involve the central incisors. In the past, fractured teeth were either extracted, trimmed and leveled, or restored with cast restorations. The learning objective of this article is to stimulate a shift in treatment strategy towards aesthetic reattachment of fractured segments. Indications and limitations for reattachment are outlined, including the primary and secondary restorative efforts. Innovative operative techniques that improve the aesthetic, biologic, and mechanical variables of the reattachment treatment option are presented.
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Porcelain veneers, despite all appearances to the contrary, rank as one of the most demanding and technique sensitive applications in esthetic restorative dentistry. Given the minute dimensions of these restorations and the partial nature of coverage, the temporization of multiple veneers provides clinicians with a notable challenge. The optimum placement of porcelain veneers depends on the clinician establishing and maintaining the patient's gingival health during the provisional treatment phase, so that there is no opportunity for inflamed sulcular tissues to compromise the final adhesive effort. This is best achieved using provisional restorations with the correct emergence profile, as well as accurate and amply sealed restorative margins. The purpose of this paper is to introduce a new temporization technique for multiple veneers that assures predictable marginal fidelity, allowing for a "temporary" yet adequate seal of the acrylic facing the dental substrate, and elective detachment at the definitive bonding appointment.
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Restitution of the complex central sulcular portion of teeth is extremely difficult when direct tooth-colored restorative materials are used, because sculpturing of the solid polymerized mass is accomplished mechanically with burs. When the initial carious lesion presents within a shell of undermined yet intact enamel, the preoperative occlusal morphology provides an ideal index of the esthetic and functional anatomy. The preoperative occlusal morphology is recorded in a transparent registration material, and then the registration is used as an index to reproduce the preoperative occlusal morphology in the final incremental restorative layer. Photopolymerization of the restoration is initiated through the translucent index and completed with surface approximation of the light source once the index has been removed.
The objective of restorative treatment of teeth with incomplete fractures is to minimize flexure of the compromised cusps to prevent propagation of the crack. These goals can be addressed with resin-bonded posterior ceramic restorations, but long-term integrity rests on the efficiency of the restoration's bond to the dental hard tissues. Success is dependent on diligent operative performance throughout the entire procedure. Some tips for achieving successful preparation, provisionalization, and partial-coverage restoration of the incompletely fractured posterior tooth are discussed.
Approximal carious lesions provide unique diagnostic and restorative challenges for clinicians interested in conserving tooth structure. Direct access reduces diagnostic doubt and facilitates optimal restorative management. The direct access afforded to newly erupted posterior teeth provides an incomparable window of opportunity to the proximal surfaces. Optimal management is limited to the interval between exfoliation and eruption, because access is lost once the erupting adjacent permanent teeth come into contact. Diagnostic and restorative strategies accomplished after creation of direct access to approximal lesions are discussed.