Extrusion of Endodontic Filling Materials: Medico-Legal Aspects. Two Cases

The Authors describe two cases of alleged malpractice due to overfilling. The aim of this article is to underline some medico-legal aspects regarding the quantity of extruded material which may be considered acceptable and the consequent damage to the patient

The effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction

<p>Abstract</p> <p>Background</p> <p>Together with diagnosis and treatment planning, a good knowledge of the root canal system and its frequent variations is a necessity for successful root canal therapy. The selection of instrumentation techniques for variants in internal anatomy of teeth has significant effects on the shaping ability and cleaning effectiveness. The aim of this study was to reveal the differences made by including variations in the internal anatomy of premolars into the study protocol for investigation of a single instrumentation technique (hand ProTaper instruments) assessed by microcomputed tomography and three-dimensional reconstruction.</p> <p>Methods</p> <p>Five single-root premolars, whose root canal systems were classified into one of five types, were scanned with micro-CT before and after preparation with a hand ProTaper instrument. Instrumentation characteristics were measured quantitatively in 3-D using a customized application framework based on MeVisLab. Numeric values were obtained for canal surface area, volume, volume changes, percentage of untouched surface, dentin wall thickness, and the thickness of dentin removed. Preparation errors were also evaluated using a color-coded reconstruction.</p> <p>Results</p> <p>Canal volumes and surface areas were increased after instrumentation. Prepared canals of all five types were straightened, with transportation toward the inner aspects of S-shaped or multiple curves. However, a ledge was formed at the apical third curve of the type II canal system and a wide range in the percentage of unchanged canal surfaces (27.4-83.0%) was recorded. The dentin walls were more than 0.3 mm thick except in a 1 mm zone from the apical surface and the hazardous area of the type II canal system after preparation with an F3 instrument.</p> <p>Conclusions</p> <p>The 3-D color-coded images showed different morphological changes in the five types of root canal systems shaped with the same hand instrumentation technique. Premolars are among the most complex teeth for root canal treatment and instrumentation techniques for the root canal systems of premolars should be selected individually depending on the 3-D canal configuration of each tooth. Further study is needed to demonstrate the differences made by including variations in the internal anatomy of teeth into the study protocol of clinical RCT for identifying the best preparation technique.</p

Soft tissue management: flap design, incision, tissue elevation and tissue retraction

The ultimate goal in surgical endodontics is not only the eradication of periapical pathosis but also preservation of periodontal conditions using suitable surgical techniques. Acceptable treatment outcomes are no longer possible without consideration of esthetic consequences for all involved dentoalveolar structures. During surgical endodontics the cortical bone is exposed by incising, elevating, and reflecting a full-thickness tissue flap. Certain basic principles must be considered before deciding on the type of incision and flap design. Thorough knowledge of regional anatomical structures in conjunction, as well as prevailing periodontal conditions affect and must be considered when making the proper decision on how and where to reflect the mucoperiosteal tissues. Various modes of incision can be selected, including horizontal, sulcular, submarginal, and vertical releasing incisions. The variety of flaps reflects the number of variables to be considered before choosing an appropriate flap design. While many flap designs have been suggested over the years, some have become obsolete and new techniques have emerged. It is critical that incisions and tissue elevations and reflections are performed in a way that facilitates healing by primary intention. This can be obtained by complete and sharp incision avoiding severing or traumatizing the tissues during elevation; it is equally important to prevent drying of tissue remnants on the root surface and drying of the flap during the procedure. The introduction of microsurgery to surgical endodontics attempts to minimize trauma and to enhance surgical results. Because of the combination of magnification and more delicate instruments, improved and careful tissue handling has become possible. Additional improvements in flap design and soft tissue manipulation are considered key elements in enhanced biological and esthetic outcomes of marginal soft tissues