ABSTRACT
Aims: The aim of this study was to evaluate the effect on the degree of conversion of Tetric N-Ceram Bulk Fill Composite subjected to preheat treatment, postcure heat treatment, and combined heat treatment. Materials and Methods: A total of 90 samples were prepared from Tetric N-Ceram Bulk Fill using customized stainless steel molds and divided into six groups of 15 samples each based on the heat treatment. Group I (control group): no heat treatment, Group II: preheat treatment at 60°C, Group III: postcure heat treatment at 100°C, Group IV: postcure heat treatment at 200°C, Group V: combined preheat treatment at 60°C and postcure heat treatment at 100°C, and Group VI: combined preheat treatment at 60°C and postcure heat treatment at 200°C. The degree of conversion was analyzed using Raman spectrometer. Statistical Analysis Used: Data were analyzed using analysis of variance followed by the Scheffé test using Statistical Package for the Social Sciences 20.0 version. Results: The order of values of degree of conversion from maximum to minimum for the groups are as follows: Group VI (98.77 ± 0.52) > Group V (97.11 ± 0.78) > Group IV (95.00 ± 0.86) > Group III (93.00 ± 1.22) > Group II (86.88 ± 1.36) > Group I (76.55 ± 1.42). The statistical analysis revealed a statistically significant difference between the groups (P < 0.05). Conclusions: Combined heat treatment samples showed better values of degree of conversion.
ABSTRACT
AIM: The aim of the study to compare the cyclic fatigue resistance of FlexiCON (Edge Endo) files in rotary versus reciprocating motion in coronal, middle, and apical curvature of the simulated artificial canal. MATERIALS AND METHODS: A total number of 36 new files, 25 mm length of ISO size 25 at the tip and a taper of 0.06, were used for the study and divided into two groups of 18 files each. Group I: FlexiCON X3, was used in a rotary motion and Group II: FlexiCON X1 was used in a reciprocating motion. Cyclic fatigue testing was conducted in a custom-made device that allowed for a reproducible simulation of a curved canal. The canal system, which comprised two adjustable stainless steel blocks, had a 60° angle of curvature and 3 mm width. The groups were further divided into three subgroups with six files in each, representing apical curvature (Group Ia/IIa), middle curvature (Group Ib/IIb), and Coronal curvature (Group Ic/IIc). Using X-Smart plus motor, files were used in rotary and reciprocating mode and the number of cycles to failure was recorded. STATISTICAL ANALYSIS: Data were analyzed using ANOVA and Post hoc followed by Dunnett's test and unpaired t-test using Statistical Package for the Social Sciences 16 version. RESULTS: FlexiCON X1 reciprocating files showed the maximum cyclic fatigue resistance at coronal curvature (1936.50 ± 1.09) followed by middle (1514.50 ± 1.07) and apical curvature (1487.50 ± 6.75), while FlexiCON X3 rotary files showed the maximum cyclic fatigue at the middle curvature (1106.00 ± 4.21), followed by coronal (920.00 ± 1.16) and apical curvature (757.00 ± 5.34). The statistical analysis revealed a statistically significant difference (P = 0.001) between the two groups. CONCLUSION: FlexiCON X1 reciprocating files showed better cyclic fatigue resistance at coronal, middle, and apical curvature compared to FlexiCON X3 rotary files.
