Gençoğlu, Oruçoğlu, Helvacıoğlu B) (P<.05). However, no difference was found be- ment of a small air bubble can be observed by la- tween Microseal and lateral condensation tech- ser diodes computer controlled rather than visual niques (P>.05). Although Thermafil showed the following. least leakage statistically the difference was not According to this study, the core (Thermafil, significant among Thermafil, Quick-Fill, Soft Core Quick-Fill and Soft Core) techniques and System B and System B. showed better sealing properties than Microseal The positive controls demonstrated extreme and lateral condensation techniques. amounts of apical leakage. Mean leakage for the Beatty et al5 and Dummer et al17 also found the positive controls was observed to be 52.5±0.10 Thermafil technique to result in less leakage than µl.cmH2O-1.min-1.10-4 1.2 atm. The negative con- did the lateral condensation technique. In our pre- trols registered no detectable bubble movement vious dye leakage study, Thermafil QuickFill core at 1.2 atm, for a minimum of 5 min before begin- techniques were found to be superior to lateral ning of each data collection. condensation technique.18 Pommel and Champs19 investigated apical sealing of single-cone, lateral dIscuIon condensation, vertical condensation, Thermafil In this in vitro study, different obturation tech- and System B obturation techniques by using fluid niques’ apical leakage was tested using a new filtration microleakage system taking measure- computerized fluid filtration meter. In vitro dye ments at 24 hours and 1 month. They found that leakage tests are very popular in literature, be- the single cone technique produced the most api- cause of easy use and cheap laboratory processes. cal leakage in 24 hours. They indicated that this But recently, because of the high number of appli- result was attributable to the greater volume of ance variations, contradictory and non-compara- sealer required for the single cone technique. Af- ble comments, entrapped air phenomena and the ter 1 month, they found that the Thermafil, System reliability of dye leakage tests are questioned.15 B and vertical condensation techniques produced One of the major problem related to the dye pene- less leakage than did the two other techniques. The tration method is that entrapped air in a void along lateral condensation showed more apical leakage a root canal filling may hinder dye penetration.16 after 1 month, whereas the single cone technique Goldman et al12 demonstrated the usefulness of produced the greatest leakage. It seemed that dye penetration method at their experiment with the use of a larger volume of sealer results in unfilled root canals. From that point of view, fluid shrinkage more often than does the use of a small filtration microleakage test is supposed to be a volume, as was the case with the cone and lat- better alternative than dye leakage tests for de- eral condensation techniques showed much more termining the leakage. The pressure applied in leakage than the compaction technique. Kontaki- this method helps to eliminate the entrapped air otis et al20 investigated long term sealing ability of in root-canal fillings. The additional advantages different sealers and found more leakage after 2 of fluid filtration can be listed as: the measure- years storage in water than before storage. In the ments can be repeated at various time periods, present study, the specimens were kept in humid- the exact time that the maximum leakage occurs ity for 2 years to create the most microleakage. can be determined; the samples are not affected The reduced ratio of sealer to gutta-percha may from the test procedures. Also, by fluid filtration improve the long term seal provided by root canal test, trough and trough evaluation of the leakage fillings. Endodontic sealers are soluble materials pattern can be made. Dye leakage test does not and the shrinkage may result in potential leakage include the whole length of the root-canal fillings. pathways in root canal fillings.21,22 Wu et al23 re- Such a full-length observation can be stimulated ported that gross amounts of sealer may result in clinical leakage and infection caused by leakage increasing amount of leakage. Gencoglu24 evalu- models. ated the sealer-gutta-percha ratio in Therma- The computerized fluid filtration meter used in fil, Quick-Fill, Soft Core Microseal System B and this study has some advantages over the conven- lateral condensation techniques. They found that tional ones with computer controlling and digital Thermafil, JS Quick-Fill and Soft Core techniques air pressure arrangement. Additionally, the move- had more gutta-percha content than Microseal, April 2007 - Vol.1 101 European Journal of Dentistry