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The Authors evaluate four different techniques for root canal filling by means of a stereo-microscope analysis of extracted teeth sections. The results indicate that: 1) the single-cone technique shows poor apical seal; 2) the Mc Spadden thermomechanical condensation technique produces good apical seal but often causes overfilling; 3) the vertical condensation and 4) the lateral condensation of gutta-percha confirm their efficacy, nevertheless the Authors recommend the second one because it is easier and request shorter time of execution.

Two Macaca (fascicularis) monkeys were used to study the effect of two warm endodontic condensation techniques (Endotec and vertical condensation method) on periodontal tissues. The specimens were histologically evaluated at 3 and 32 days after the endodontic treatments were completed. In this study the periodontium was divided into coronal, middle, and apical thirds. Results indicated that there was no heat-related damage to periodontal tissues from either of the two methods employed. However, some Endotec specimens generated small, reactive inflammatory infiltrates that were restricted to the root canal opening or adjacent periodontal membrane. Similarly, some vertical condensation specimens developed periapical inflammatory processes as well, but they were more extensive and comprised the alveolar bone and marrow spaces.

This investigation quantitatively analyzed apical leakage in teeth in which one of two new thermoplasticized gutta-percha obturating techniques were used. Apical leakage observed after use of the thermoplasticized techniques was compared to leakage found in teeth that had been obturated with conventional lateral condensation. Statistically significant differences (P less than 0.05) were found among the three groups. The lateral condensation group exhibited the least leakage, followed by the thermoplasticized group, and the thermoplasticized twist-off group exhibited the most apical leakage.

A clinical study involving 30 patients randomly selected in the department of endodontics at the Saint Joseph University of Beirut and in private practice was carried out. The use of "Obtura", a high-heat thermoplasticized gutta-percha system seems to be satisfactory, the findings stressed the advantages and the disadvantages of the technique and the material. Some suggestions are advanced in order to make the use of the technique easier and more efficient.

The Authors have studied the efficacy of the sealing effect of thermomechanical compaction of guttapercha according to McSpadden with an in vitro analysis on undecalcified tooth sections and with a clinical evaluation of ten patients with periapical lesions. The analysis of the results has shown a good sealing capacity of the McSpadden technique.

The incidence of vertical root fractures and the amount of root distortion created during lateral condensation of gutta-percha with either D11 spreaders or B-finger pluggers were evaluated in vitro. Fifty-five extracted human, single-rooted teeth were instrumented using the step-back flare technique. Ten teeth served as positive controls (obturation to the point of fracture) and five teeth as negative controls (prepared but not obtured). Strain gauges were attached to the root surfaces. In the experimental group, 20 teeth were obturated using a D11 spreader and 20 with a B-finger plugger. Recordings were made of root distortion (expansion) created during obturation. Then, after sectioning the teeth, root surfaces of obturated samples were examined for fractures under the scanning electron microscope. Only the more tapered spreader, the D11, produces vertical root fractures, although very few in number. Also, the D11 spreader caused greater root distortion than did the B-finger plugger.

Filling the root canals in teeth after apexification is one useful clinical application of the thermoplasticized gutta-percha. We described 7 cases which Ultrafil was used in order to fill the canals. In all of them we made X-ray check-up.

Forty straight canals of maxillary canines and 40 curved canals in 20 mesial roots of mandibular molars were instrumented and randomly assigned to two groups of 40 canals each. For the experimental group, the canals were obturated using the Thermafil obturation technique. Lateral condensation was used for the obturation of the control group. Kerr pulp canal sealer was used in both group. The specimens were stored in 100% humidity for 1 wk. All teeth were suspended in black India ink for 14 days and decalcified in 5% nitric acid over a 2-day period. The teeth were then dehydrated in a graded series of alcohol to 100%. Methyl salycilate was used to clear and store the teeth for 48 h. Linear dye leakage measurements showed that canines obturated with the lateral condensation technique leaked significantly less than those obturated using the Thermafil technique (p = 0.02). The difference was not statistically significant in the molar roots.

This article presents a method that uses an amalgam capsule and an amalgamator to simplify the preparation of eucapercha paste. The pestle, rubbing against the gutta-percha inside the amalgam capsule, generates enough frictional heat to blend the gutta-percha and the eucalyptol. The consistency of the mixture can be adjusted for a variety of clinical situations.

This study compared the apical seal produced by four obturation techniques. The Canal Finder system was compared with lateral condensation, the Ultrafil system, and the sectional warm gutta-percha techniques. Forty-two anterior single-rooted teeth were instrumented. Ten teeth were not obturated and served as positive and negative controls. The apical seal was tested for leakage with 0.25% methylene blue dye. The teeth were shaved horizontally and dye penetration was measured with a Boley gauge. Results revealed there was no statistically significant difference among the four obturation techniques.

Temperature elevations of 10 degrees C above body temperature, of duration greater than 1 minute, may be sufficient to cause bone tissue injury. Temperature rises on the root surface in excess of 10 degrees C have been shown in studies in vitro of thermoplasticized gutta-percha root filling techniques. To determine whether results in vitro at room temperature could be extrapolated to conditions in vivo, temperature elevations were recorded at the mid-point on the root surface of the canine tooth in the ferret during thermomechanical compaction of gutta-percha. The time taken for the temperature to return to normal was also measured. There was no statistically significant difference between temperature elevations recorded in vitro and those measured in vivo. A linear extrapolation may therefore be made from results recorded at room temperature. Temperature elevations dissipated more rapidly in vivo than in vitro; this may be due to the cooling effect of the microvasculature of the periodontal membrane.

An in vivo investigation is described and a histological evaluation made of the effect of canal obturation by thermomechanical compaction of gutta-percha and sealer on the cementum on the lateral surface of the root and adjacent periodontal membrane and alveolar bone of the ferret canine after time intervals of 24 hours, 20 days and 40 days. These tissue reactions were compared with those in the roots of control teeth filled by lateral condensation of cold gutta-percha and sealer. Iatrogenic damage was apparent in a minority of the experimental specimens 20 and 40 days after obturation.

An in vitro endodontic leakage model was used to compare the sealing ability of conventional retrograde amalgam fillings with a new retrograde filling technique by measuring dye leakage quantitatively. The new technique consisted of retrograde preparation of the root canal using the Endocursor, an endodontic handpiece. The canal was then filled with sealer and injection-moulded gutta-percha, using either the Hygenic Ultrafil system or the Unitek Obtura method. In both cases the gutta-percha was vertically condensed and subsequently cold-burnished. The two experimental groups and the amalgam group each consisted of 20 extracted human canine teeth and lower premolars. The results were analysed statistically by ANOVA and a Student-Newman-Keuls multiple comparison test. After 1 week at 37 degrees C, very little leakage was observed in the amalgam and gutta-percha groups. After a second week, during which leakage was enhanced by gas pressure, leakage in the amalgam group was significantly greater than that in the gutta-percha groups (P less than 0.01). There were no significant differences between the two experimental gutta-percha groups. It is concluded that the new retrograde filling technique causes less leakage than the conventional amalgam retrograde filling technique in an in vitro model.

Seventy-six extracted human permanent canines and premolars with single canals were used in this study. The crowns were removed, the canals were instrumented, and the roots were randomly divided into four groups of 18 each. Three groups were medicated with Ca(OH)2 USP, Calasept, and Vitapex, respectively, while the control group was not medicated. The roots were incubated in 100% relative humidity at 37 degrees C for 1 wk, after which the medicaments were removed and the canals were enlarged to the next file size. One tooth in each group was examined in the scanning electron microscope while the remaining roots were filled with gutta-percha using a lateral condensation technique. The roots were placed in 2% methylene blue solution for 2 wk and both linear and volumetric dye penetration evaluated. A highly significant correlation between linear and volumetric leakage was observed. The leakage among the experimental groups was not significantly different, but was significantly less than in the control group.

An in vitro dye leakage study was performed to evaluate the sealing ability of the following retrofilling materials: high- and low-temperature injectable thermoplasticized gutta-percha with and without sealer, a glass ionomer cement, and amalgam with and without varnish. The roots of 105 extracted human maxillary anterior teeth were instrumented and obturated with single cones of gutta-percha and sealer. The apical 3 mm of the roots were then resected and 2-mm deep retrograde preparations were prepared. Each root was then randomly placed into one of seven groups and retrofilled with one of the test materials. After 72 h in India ink, the roots were cleared and evaluated for leakage using a stereomicroscope. Statistical analysis of the results indicated that injectable high-temperature gutta-percha without sealer demonstrated significantly more leakage than the other materials. There were no significant differences in leakage among the other evaluated materials.

The root canals of 27 caries-free human cuspids were divided into 3 groups of 9 teeth each. Group I was mechanically prepared with reamers and files. Alternate irrigation with 5.25% NaOCl and 3% hydrogen peroxide was used between each instrument. The group II root canals were prepared with the use of alternate irrigation with the same concentrations of NaOCl and hydrogen peroxide and finally flushed with 17% EDTA and NaOCl solution. Group III was prepared mechanically with the use of sterile distilled water as an irrigant followed by a final flush with 17% EDTA solution. The root canals of all specimens were obturated with gutta-percha points and Tubliseal by means of the lateral condensation technique. After the root canals were obturated, samples of each of the three groups were immersed in separate flasks containing Streptococcus mutans, Staphylococcus epidermidis, and Corynebacterium hofmannii. All the microorganisms tested invaded the coronal dentin--where the access cavity had been sealed with Fynal--and/or the main foramen.

Step-Back technique or similar is the method of choice for the thermoplasticized gutta-percha. There are no significant differences in the apical seal produced by different filling techniques. There is a little volumetric reduction, similar than in the regular gutta-percha points, when cooling gutta-percha. The results of a clinical study about thermoplasticized gutta-percha with and without sealer are similar than in a control group filled by lateral condensation.

With the use of the CAVIENDO and the ENDOTEC, and the improved instruments; the calibrated M SERIES PLUGGER/SPREADERS and new ENDO DIAMOND ACCESS BUR, a high-tech biologic approach to endodontic therapy has been developed that allows the operator to perform root canal treatment efficiently, effectively and with ease, achieving the highest degree of success.

Many materials have been used as retrograde fillings. Zinc oxide and eugenol, cavit, composite, gold foils, and other materials have been used in an attempt to seal the apical extent of the root canal. However, the most common material is amalgam.

Sixty-four teeth were treated by means of apicoectomy with retrograde gutta-percha filling with the use of new instruments that we devised. The new instruments consisted of a biangle explorer, angle reamers, and angle files. Operations with this technique showed a success rate of 95.3% (61/64 teeth). We conclude that our technique for apicoectomy with retrograde gutta-percha filling is not only simple in procedure, but also shows excellent results.

Extracted teeth, root-filled by single cone and lateral condensation techniques, using friction fitted and solvent (chloroform and eucalyptol) dip-fitted primary gutta-percha cones, were compared with respect to apical sealing as measured by length of dye penetration and frequency of no dye penetration. Overall, the single cone techniques were significantly more effective than lateral condensation techniques regarding length of dye penetration. The single cone techniques were not significantly different from the lateral condensation technique which employed chloroform dip-fitted primary gutta-percha cones regarding length of dye penetration. The single cone and lateral condensation techniques which utilized chloroform dip-fitted cones ranked first and second with respect to frequency of no dye penetration.