Micro-computed tomography and computerized fluidfiltration device assessment of filling quality of rootcanals filled BY different obturation techniques

The aim of this study is to investigate the quality of different root canal filling techniques by micro-computed tomography and computerized fluid filtration device; to compare the results obtainde with each other. In this study, 48 extracted, single-rooted and single canaled mandibular premolar human teeth without caries were used. Teeth were separated from their crowns and all roots were standardized to a length of 12 mm. After the root canal preparation with ProTaper Next Ni-Ti rotary files up to X4 file, samples were divided into 4 experimental groups (Group 1: Cold lateral condensation technique, Group 2: Ultrasonic lateral condensation technique, Group 3: Continuous wave of condensation technique and Group 4: Thermoplastic core technique) with 12 teeth per group and root canal fillings were made with different techniques. After the obturation of root canals, groups were evaluated in terms of percentage of root canal filling volumes, internal, external and combined gaps in apical, middle and coronal regions by scanning the samples with micro-computed tomography. Then apical leakage of the groups were measured by computerized fluid filtration device. All data were compared and statistically evaluated by a statistical software. The statistical analysis showed that the evaluations were meaningful among some groups. As a result of the statistical analysis of micro-computed tomography measurements, which was the first step of the study; the minimum percentage of root canal filling volume between the groups was measured in Group 1. No statistically significant difference was found in percentage of root canal filling volume between the other groups. Among the regions tested, the minimum percentage of root canal filling volume was seen in the apical region, while there was no statistical difference between the middle and coronal regions. Also no statistically significant difference was found between groups and regions in terms of internal gaps. The maximum amounts of external and combined gaps were seen in Group 1. There was no statistically significant difference between the other groups in terms of external and combined gaps. Among the regions, the maximum amounts of external and combined gaps were seen in the apical region, while there was no statistically significant difference between the other groups. In the measurements made by the computerized fluid filtration device which was the second step of the study, the most amount of apical leakage was observed in Group 1. While Group 2 and Group 3 showed the least amount of apical leakage, it was found that the difference between them was not statistically significant. In Group 4, apical leakage values were statistically lower than Group 1 and the difference was significant. When the results obtained within the limitations of this study were evaluated, it was seen that all groups tested had different amounts of leakage and external and combined gaps. However, in both the micro-computed tomography analyzes and computerized fiquid filtration measurements, the minimum amounts of leakage and / or external and combined gaps were seen in the Elements Free Obturation and LM-ProPower groups while maximum amounts of leakage and / or external and combined gaps were seen in the cold lateral condensation group. In the light of the informations obtained from this study, in order to increase the canal filling quality and apical sealing in the root canal treatment, it may be advisable to use continuous wave of condensation or ultrasonic energized lateral condensation techniques by using devices such as Elements Free Obturation and LM-ProPower. In addition, a moderate correlation was detected between micro-computed tomography and computerized fluid filtration techniques. In the light of this result, it is concluded that root canal filling quality can be considered more practical by using computerized fluid filtration technique instead of expensive and time consuming techniques such as microcomputer tomography. However, it is thought that the relationship between these two techniques should be supported by other studies. Key words: Root canal filling techniques, canal filling quality, cold lateral condensation technique, ultrasonic technique, continuous wave of condensation, thermoplastic core, micro-computed tomography, computerized fluid filtration technique.