The effect of three different primary teeth rotary instrument systems on the amount of apically extruded debris in pulpectomy of primary teeth

One of the main reason of premature loss of primary teeth is periapical infection. Routinely root canal treatment in primary teeth is effective in the treatment of irreversible inflammation or infected pulp tissue. During canal preparation necrotic debris, pulp remains, microorganisms, dentin chips, and irrigants can be extruded into the apical area. They can cause inflammation, delay of healing and be reason to permanent teeth germs' damage. The aim of our study is to determine the amount of debris extrusion and preparation time during root canal treatment with three different primary teeth rotary systems and identify the most effective of these systems. Our study was carried on a total of 80 second primary molar teeth in children with extraction indications aged 4-6. In vitro root canal preparation was applied, using three different primary teeth rotary file systems. The teeth were randomly divided into four subgroups of 20 teeth, each with computer-based randomization program. Root canal preparation was carried on the teeth of all groups (Group 1: AF Baby Rotary, Group 2: Easyinsmile Baby Rotary, Group 3: Endoart Pedo Gold, Group 4: Manual files) according to the manufacturer's recommendations. Extruded debris during preparation was collected in pre-weighed empty Eppendorf tubes. Eppendorf tubes were stored in an incubator at 37°C for 14 days until the extruded irrigation solution completely had evaporated. The weight of the apically extruded debris was obtained by subtracting empty weights from weight measurements taken after incubation of Eppendorf tubes. In the study, file systems' working time was calculated by chronometer. The duration of the file in the canal, file change time, and the time of irrigation were included in working time. The conformity of the data obtained in the study to the normal distribution was evaluated with the Shapiro Wilk test. In comparison between groups, Mann Whitney U test and Bonferroni correction were used after the Kruskal Wallis test if necessary. Wilcoxon test was used for intragroup comparison before and after preparation. P-value less than 0.05 was considered statistically significant. According to the results of our study, despite the difference between the weights values of Eppendorf tubes before and after preparation in each group was statistically significant (p<0.001), this situation was not statistically significant between the groups (p>0.05). Despite the percentage of extruded debris did not make a statistically significant difference, it was found most in manual K files and at least in AF Baby Rotary file systems. When the working time data is examined, the relationship between AF Baby Rotary-Easyinsmile Baby Rotary, Easyinsmile Baby Rotary-manual K, AF Baby Rotary-Endoart Pedo Gold, AF Baby Rotary-manual K, and Easyinsmile Baby Rotary-manual K was statistically significant (p=0.003; p<0.01, p<0.001), along with between Easyinsmile Baby Rotary-Endoart Pedo Gold was not statistically significant (p>0.01). The longest working time was found in the manual K files. The shortest working time was detected in Endoart Pedo Gold file systems. Primary teeth Ni-Ti rotary file systems reduce the working time and extrude less debris percentage compared to manual files; it can improve the effectiveness of root canal treatment, positivly influencing the health of permanent teeth germ and cooperation of the child. For this reason, primary teeth Ni-Ti rotary file systems are considered to be a good choice for pediatric dentists. Key Words: Primary teeth, Root canal treatment, Apical debris, Time