An evaluation of the Thermafil endodontic obturation technique.

The purpose of this study was to evaluate the Thermafil endodontic obturation technique and to compare it with laterally condensed gutta-percha. Thirty-seven maxillary central incisors were similarly prepared and divided into groups. Seventeen were obturated with Thermafil and 17 with lateral condensation. Three served as controls. After vacuum staining, all teeth were cleared and apical dye penetration was evaluated by two independent observers. Average leakage values were 0.24 mm and 1.32 mm for Thermafil and 0.47 mm and 1.18 mm for lateral condensation. There was no significant difference between the techniques, although a difference between evaluators was noted. Final results point to the relative subjectivity of in vitro leakage studies. When comparing the obturation times of both techniques, the Thermafil technique averaged 2 min 56 s while lateral condensation took 3 min 26 s. Statistical analysis showed no significant difference in obturation times.

Chloroform in the endodontic operatory.

This article reviews the role chloroform has played in dentistry and describes an occupational health clinical investigation into the possible hazards of chloroform use in the operatory. Due to a Food and Drug Administration ban on drugs and cosmetics containing chloroform, there has been some confusion as to whether the use of chloroform in the practice of dentistry is considered unsafe or has been prohibited. Utilizing common endodontic treatment methods employing chloroform, this study reports no negative health effects to the dentist or assistant and air vapor levels well below Occupational Health and Safety Administration mandated maximum levels. The report concludes that, with careful and controlled use, chloroform can be a useful adjunct in the practice of dentistry. The Food and Drug Administration has no jurisdiction over a dentist's use of chloroform in clinical practice and has not proven that chloroform is a human carcinogen.

Reference block for auxiliary cones.

A technique is described for fabricating a reference block which will allow the practitioner to select the accessory cones most correctly corresponding to the spreader used. The technique utilizes materials common to the dental office and is simple enough to allow fabrication of a new block whenever the obturation instruments or materials are changed.

An evaluation of the ability of a dentin plug to control extrusion of thermoplasticized gutta-percha.

Overextension of gutta-percha when using any of the thermoplasticized obturation techniques has often been mentioned as a possible deleterious yet common sequela. The purpose of this study was to test a means of controlling the extrusion of material at the apical seat of the preparation when thermoplasticized gutta-percha techniques are used. Eighty human maxillary central incisors were prepared via step-back technique, in vitro, with apical stops placed 1 mm short of the actual apical foramen and the foramen was checked for patency. Teeth were divided into 10 groups, embedded in special "tooth trays," and four groups had intentional dentin plugs of 1-mm thickness placed to enhance the apical stop. A tooth tray of patent teeth and one of dentin-plugged teeth were than obturated by (a) the Obtura technique, (b) the Ultrafil technique, (c) the Touch 'n Heat technique, and (d) the Thermafil technique. Teeth were removed from the trays, extruded material carefully excised and weighed, and the weights evaluated by statistical analysis to determine results. When foramen patency was maintained, the Thermafil technique demonstrated significantly greater problems with overextension of material than did other techniques. The dentin plug served as an effective means of preventing extrusion.

Failure of endodontically treated teeth: classification and evaluation.

All endodontically treated teeth that were extracted over a 1-yr period in a busy group practice were evaluated for cause of failure. The 116 teeth collected were classified into major failure categories of prosthetic, periodontic, and endodontic origin. Of the teeth, 59.4% were prosthetic failures which were due primarily to crown fracture. Teeth that had been crowned had greater longevity than uncrowned teeth. Periodontal failures constituted 32% of the study. Only 8.6% of the failures were due to endodontic causes, but these failures became evident more quickly than those in the other categories. A classification of failures is presented, and the results are analyzed.