Alvin Arlen Krakow

Three-dimensional obturation of the root canal using injection-molded, thermoplasticized dental gutta-percha

Abstract The technique of injection-molding was applied to thermoplasticized dental gutta percha in vitro. Teeth were biochemically instrumented before obturation of the root canal space. Thermoplasticized gutta percha was injected, with and without the use of a sealer, using a pressure syringe. The quality of the seal was assessed by dye penetration studies. The findings showed that the injection-molding technique leads to a seal comparable to that of conventional approaches. The technique holds promise for in vivo use.

Scanning electron microscopic study of root canal obturation using thermoplasticized gutta-percha

Forty teeth with single canals were biomechanically prepared for root canal obturation. Ten teeth were obturated by injection of thermoplasticized gutta-percha with use of a pressure syringe. The remaining 30 teeth were divided into three equal groups and were obturated using lateral condensation, warm gutta-percha with vertical condensation, and Kloroperka, respectively. The adaptation of the root canal fillings to the surrounding dentinal walls was examined under the scanning electron microscope with use of freeze fracturing in liquid nitrogen to produce samples showing the gutta-percha-dentin interface. The findings indicated that the injection-molding technique resulted in obturation of the root canal system, which was at least comparable to that obtained in other conventional approaches.

Pulpal and periapical tissue responses in conventional and monoinfected gnotobiotic rats

Abstract The effect on healing of mechanically damaged pulp and periapical tissues in the presence of either the normal oral flora or a select microorganism was studied. Thirty-five conventional and gnotobiotic rats, infected with Streptococcus mutans (Strain 6715), had the mesial palatal roots of their upper right and left first molars intentionally overinstrumented with a standardized No. 10 stainless-steel endodontic reamer. Thirty-five teeth were exposed to the oral environment for the duration of the study, and in the other thirty-five, silver amalgams were placed immediately into the access cavities in order to effect a seal. The animals were killed at various intervals over a period of 30 days after endodontic instrumentation, and the histologic specimens were studied. The periapical tissue reactions seen in this experiment could be related directly to the bacterial invasion of the root canal. Where microorganisms were found along the entire length of the root canals, i.e., in the teeth of the conventional animals without amalgam seals, the tissue reaction was severe. When the inoculum was limited, so was the reaction.

In vivo study of temporary filling materials used in endodontics in anterior teeth.

The sealing efficacy of temporary endodontic filling materials was tested in vivo. The following materials were studied: Cavit, Caviton, gutta-percha, three types of zinc phosphate cement, and zinc oxide and eugenol. All the materials were tested in the access cavity of the same anterior tooth in ten different patients for a minimum of 1 week. Seepage was determined bacteriologically by culturing a cotton pellet which was sealed into the access cavity. On the basis of the quantity of microorganisms grown anaerobically, differentiation was made between no leakage, minor leakage, and gross leakage. Findings with Cavit and Caviton are essentially the same and show no or minor leakage in the vast majority of tests. Gutta-percha showed gross leakage in six out of eight tests. Phosphate cements showed no leakage in more than two thirds of the tests.

Clinical use of injection-molded thermoplasticized gutta-percha for obturation of the root canal system: a preliminary report

The technique of injection-molded thermoplasticized gutta-percha was applied in vivo in a variety of clinical cases. Teeth were biomechanically instrumented before obturation of the root canal space. Thermoplasticized gutta-percha was injected using a recently developed delivery system. Healing in 125 cases was evaluated on the basis of clinical and radiographic findings.

The effect of instrumentation and flushing of freshly extracted teeth in endodontic therapy: a scanning electron microscope study.

One objective of root canal therapy is the debridement of pulp from the root canal space. Recent scanning electron microscope studies have evaluated the adequacy of biomechanical preparation of root canals using various irrigants. 1–3 The results indicate that water is as effective as chemical medicaments during biomechanical preparation of root canals. 1-2 Consequently, some confusion exists concerning which irrigant should be used during debridement procedures. The purpose of this investigation is to determine if findings of earlier studies can be duplicated when larger numbers of teeth are used in each experimental group and to determine which endodontic medicament has the greatest potential to aid instrumentation during biomechanical procedures.

A comparison of the management of pulpal pathosis in deciduous and permanent teeth

Abstract Endodontic treatment in the adult dentition, as practiced by most endodontists, does not include vital pulp therapy procedures, whereas endodontic treatment in the deciduous teeth, as practiced by most pedodontists, is mostly limited to vital pulp therapy procedures and rarely includes complete root canal therapy. There are many advantages to maintaining pulpless deciduous teeth, and suggestions are presented to assist the clinician in solving the problems of instrumenting and filling these canals. Vital pulp therapy procedures can also enjoy a high success rate in the adult dentition. By combining accurate diagnosis with proper case selection and treatment techniques, successful vital pulp therapy procedures are predictable. Accordingly, complete root canal therapy can often be avoided in the adult dentition.

Therapeutic induction of root formation in the exposed incompletely formed tooth with vital pulp

Abstract It is suggested that root canal treatment subsequent to pulpotomy which has resulted in completion of root formation is indicated only when a post and core are required for adequate restoration of the crown of the tooth.

Effects of vitamin E dietary supplements on the exposed dental pulp in rats

Forty adult male Sprague-Dawley rats were divided into two equal groups, control (Group 1) and experimental (Group 2). Group 2 received 100 mg of dl-alpha-tocopherol acetate (vitamin E) twice weekly by the oral route. After 2 weeks the animals in both groups were subjected to pulp exposures that were capped with zinc oxide and eugenol and to pulp exposures that were left open. The oral administration of 100 mg dl-alpha-tocopherol acetate in the Group 2 animals was continued for periods of 1 day to 4 weeks after the operative procedures. The animals were killed 1 day, 3 days, and 1, 2, and 4 weeks after the procedures. The most severe, prolonged, and extensive pulpal disease was seen in both groups when the pulp exposure was left open to the oral flora. The most favorable repair and healing results took place after 1, 2, and 4 weeks in the Group 2 animals in pulp exposures covered with zinc oxide and eugenol.

Retrograde instrumentation and obturation of the root canal space

A treatment approach is described combining retrograde biomechanical instrumentation with retrograde obturation of the root canal space prior to insertion of a retrograde filling material in the apical terminus of the canal.