Effects of calcium hydroxide paste medication on coronal leakage.

The purpose of this in vitro study was to examine the coronal leakage of canals medicated with Ca(OH)(2) compared with the canals which did not receive Ca(OH)(2) medication before obturation with laterally condensed gutta-percha points and sealer. Sixty-one single rooted permanent canines and premolars were used. The crowns were removed from the cemento-enamel junction. After the canals were chemomechanically prepared, the roots were divided into three experimental groups as group 1, 2 and 3. The canals in group 1 and 2 were treated with ethylenediaminetetraacetic acid (EDTA) and NaOCl in order to remove the smear layer and then the canals were filled with Ca(OH)(2) paste. The coronal 3 mm of the cavities were sealed with Cavit and the samples were kept in an incubator at 37 degrees C for 7 days. No intra-canal medication was applied in group 3. The root canals were irrigated with NaOCl in group 1 and with EDTA and NaOCl in group 2, in order to remove Ca(OH)(2) before obturation. Two samples from group 1 and two from group 2 were examined under SEM in order to reveal the removal of Ca(OH)(2) paste. Following this, the canals in the experimental groups were obturated with gutta-percha and sealer. The roots were placed in India ink for 7 days and the linear dye penetration was evaluated. No significant statistical difference was found in the amount of coronal dye leakage between experimental groups (P > 0.05). The results of the present study indicated that the application of Ca(OH)(2) as a temporary dressing material had no effect on coronal leakage.

Evaluation of penetration and adaptation of three different sealers: a SEM study.

In this study, dentinal penetration and adaptation of three endodontic sealers were evaluated by using scanning electron microscope (SEM). Seventeen recently extracted, human maxillary anterior teeth were used. After the crowns were removed from the cementoenamel junction, the root canals were instrumented. The teeth were then randomly divided into three groups of five roots each and two teeth were used as controls. The smear layer was removed with EDTA and NaOCl. The canals were obturated with AH 26, CRCS, RSA sealers and gutta-percha using lateral condensation technique. Each root was sectioned longitudinally and then prepared for SEM evaluation. The SEM results showed that AH 26 was the best sealer penetrating into dentinal tubules and adapted to dentinal walls when compared with the CRCS and RSA. The CRCS and RSA occluded the orificies of dentinal tubules. The RSA showed that the penetration was less than AH 26 and more than CRCS.

Apical leakage of a new glass ionomer root canal sealer.

A new glass ionomer root canal sealer (Ketac-Endo) has been developed. The purpose of this study was to compare the apical leakage of Ketac-Endo and AH26 using two different filling techniques and a controlled vacuum procedure. Sixty-four extracted human maxillary anterior teeth were instrumented and divided into four groups of 15 roots each. The groups were obturated as follows: group 1, a single cone technique and Ketac-Endo; group 2, a lateral condensation technique and Ketac-Endo; group 3, a single cone technique and AH26; and group 4, a lateral condensation technique and AH26. After storage in 100% humidity at 37 degrees C for 1 wk, the root surfaces were coated with two layers of nail polish and sticky wax. All specimens were immersed in a vacuum flask containing 2% methylene blue dye solution. The air was evacuated with a vacuum pump. The roots were sectioned longitudinally, and the linear extent of dye penetration was measured. Statistical analysis revealed that there were no significant differences between any of the groups.

Comparison of apical leakage in root canals obturated with various gutta percha techniques using a dye vacuum tracing method.

In this study, residual apical microlumina remaining after obturation with five different gutta-percha obturation methods were traced with an efficient vacuum method. Seventy-nine human maxillary anterior teeth were instrumented and divided into five groups. The groups were obturated with single-cone techniques, lateral condensation, vertical condensation, Thermafil, and Ultrafil techniques. All specimens were immersed in a vacuum flask containing 2% methylene blue dye solution. The air was evacuated with a vacuum pump to an absolute pressure of 75 torr for 30 min. The roots were sectioned longitudinally and the linear extent of dye penetration was measured. Group mean linear dye penetration values were: single-cone technique, 1.55 +/- 0.95 mm; lateral condensation, 2.25 +/- 1.46 mm; vertical condensation, 2.61 +/- 2.61 mm; Thermafil 1.41 +/- 1.16 mm; and Ultrafil 3.51 +/- 4.70 mm. There were no statistically significant differences between the gutta-percha obturation methods. The clinical implications of these findings are discussed.

Effect of post preparation on the apical seal of teeth obturated with plastic thermafil obturators.

The effect of post canal preparation on the apical seal of endodontically obturated teeth with plastic Thermafil obturators was studied in vitro. Fifty-four extracted human maxillary anterior teeth were divided into four experimental and two control groups. Two groups were obturated with lateral condensation or plastic Thermafil obturator techniques; this was followed by post space preparation. Two groups were obturated as described above except that post space was not prepared. Apical leakage was determined with the use of 2% methylene blue dye solution at an absolute pressure of 75 mm Hg. There were no statistically significant differences between any of the groups. The clinical implication of these findings is discussed.

Periapical tissue reaction to root fillings with Sealapex.

The histological response of periapical tissues to root canal fillings with Sealapex, pure calcium hydroxide and gutta-percha points was studied in dogs' teeth. After pulpal extirpation the root canals were enlarged, irrigated and dried. Teeth in the first group were filled with gutta-percha points alone, those in the second group were filled with pure calcium hydroxide and gutta-percha, and those in the third group were filled with Sealapex and gutta-percha. The animals were killed after 7, 30 and 90 days and histological sections of each specimen were prepared. It was concluded that hard tissue formation was more pronounced after root filling with Sealapex than with calcium hydroxide or gutta-percha points.

[Effect of light exposure time on hardness of visible light cured composites]. / Isinlama süresinin, görünür isinla sertlesen kompozit dolgularin sertlikleri üzerine etkisi.

In this article effect of light exposure time on hardness of visible light cured composites with different microfiller ratios were investigated. For this purpose specimens with heights 1, 2, 3 mm and 6 mm in diameter were prepared. During the preparation of the specimens, half of the specimens were cured with visible light for 40 seconds and the other half for 60 seconds. Surface hardness values were measured from the top and bottom of the specimens immediately after the light source was removed with Barcol Hardness tester. Surface hardness were also measured 24 hours and 7 days later. Results were statistically evaluated.