İnternal matriks ile birlikte kullanılan MTA’nın ortograd ve retrograd uygulanmasının farklı apikal açıklığa sahip dişler üzerindeki güçlendirme etkisinin değerlendirilmesi

OBJECTIVE: The aim of this study was to determine the effect of the apical foramen diameter and different application methods of Mineral Trioxide Aggregate (MTA) on the fracture resistance of simulated immature teeth using a Universal Testing Machine. MATERIALS AND METHOD: Ninety extracted human teeth were used for the fracture resistance test. The apical foramen was prepared to a diameter of 1.0 mm or 1.4 mm to simulate the open apex of immature teeth. MTA was mixed according to manufacturer's recommendations and placed into the root canals with different apical foramen diameter by four different root filling techniques: retrograde, two-phased orthograde, and ortograde with or without internal matrix. Prepared roots were marked 2 mm below the cemento-enamel junction and embedded in transparent acrylic resin in cylinder moulds. Vertical force was applied along the long axis of the tooth at a speed of 5 mm/min, and the maximum resistance to fracture for each tooth was determined in Newton. A software package was used for the statistical analysis. The data were analyzed by using one-way ANOVA and post-hoc Tukey tests. RESULTS: A statistically significant difference could not be observed between the groups (p>0.05) whereas statistically significant differences were found between the test groups and the control groups (p<0.05). CONCLUSION: There was no significant difference between different vertical root filling techniques in increasing the fracture strength of the teeth. The diameter of the apical foramen did not have a significant effect on the fracture resistance.