ABSTRACT
AIM: The current study compared the fracture resistance of samples instrumented by two rotary files and a reciprocating file, obturated with gutta-percha and AH Plus. MATERIALS AND METHODS: A total of 60 freshly extracted mandibular premolar teeth with single roots and single canals were acquired and decoronated at or below the cementoenamel junction. The samples were randomly divided into four groups (n = 15). Group 1 control (noninstrumented/obturated), and for Groups 2-4 root canal instrumentation was done by EndoStar E5 (EE5), ProTaper NEXT (PTN), and WaveOne, respectively. Following instrumentation, the samples were obturated using gutta-percha cones and AH Plus sealer using lateral compaction. A week later, vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded and statistically analyzed. RESULTS: The mean loads required to fracture (Newton; N) for the four groups were; 388.54 (±29.93), 310.35 (±26.05), 328.40 (±20.67), and 278.54 (±34.16). The loads exhibited highly significant difference (P < 0.0001; analysis variance). The following Tukey's post hoc test confirmed, both samples in Groups 2 and 3 required similar loads for fracture (P > 0.05) and significantly higher than Group 4 (P < 0.01). CONCLUSION: The samples instrumented by EE5 and PTN exhibit similar fracture resistance.
ABSTRACT
AIM: The purpose of this in vitro study was to evaluate the vertical force required to fracture mandibular incisor teeth, obturated using gutta-percha with three different sealers. MATERIALS AND METHODS: Seventy-five extracted mandibular incisors with intact and fully formed apices, exhibiting single root and canal were acquired. The teeth were decoronated obtaining a root segments of 15 mm and were divided into five groups (n = 15). Group 1: left uninstrumented and unfilled (negative control). For groups 2-5, samples were instrumented using Protaper NEXT (X1 and X2). Group 2: left unobturated (positive control). Groups 3-5 were obturated using lateral compaction by gutta-percha and three sealers (AH Plus®, Apexit®, and EndoSequence® BioCeramic™). All the samples were prepared for fracture testing and vertical load was applied till fracture. Statistical analysis was performed using ANOVA and Tukey's post hoc test, for the data recorded of the force required in Newton (N). RESULTS: The load required to fracture exhibited a significant difference. The intergroup analysis revealed, samples obturated using bioceramic sealer exhibited higher fracture resistance (P < 0.01). CONCLUSION: The use of gutta-percha and a root canal sealer reinforces the root dentin, leading to increased fracture resistance against vertical forces. Bioceramic sealer group in them exhibited better results.
ABSTRACT
AIM: The aim of this study was to test the effect of new protocol of glide path preparation by 20/0.04 rotary file on apical extrusion of debris when instrumenting fine curved mesial canals in mandibular molars with Self-adjusting File (SAF) and compare it to a glide path prepared by 20/0.02 hand K-file and rotary OneShape (OS) and reciprocating WaveOne (WO) file instrumentation. MATERIALS AND METHODS: Sixty mandibular molars with curved mesial roots were selected and randomly divided into three groups (n = 20) for instrumentation. In two groups, glide path was prepared using 20/0.02 K-file for instrumentation by OS (size 25/0.06 taper) and WO (size 25/0.08 taper) files; in the remaining group, 20/0.04 rotary file was used for glide path preparation and instrumented by SAF (1.5 mm). The debris extruded during instrumentation was collected in preweighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry extruded debris were then weighed. One-way analysis of variance (ANOVA) was applied to the weights obtained, followed by Tukey's post hoc test for multiple comparison. RESULTS: The mean debris (g) extruded apically was 0.000651 ± 0.000291, 0.000823 ± 0.000319, and 0.000473 ± 0.000238 for Group 1 (20/0.02 + OS), Group 2 (20/0.02 + WO), and Group 3 (20/0.04 + SAF), respectively. The groups exhibited a significant difference (P < 0.01; ANOVA). Group 3 resulted in least debris extrusion compared to Groups 1 and 2 (P < 0.01; Tukey's post hoc test). CONCLUSION: Glide path prepared to size 20/0.04 and SAF 1.5 mm instrumentation produce less debris in curved mesial canals of mandibular molars, compared to glide path established by 20/0.02 and instrumentation by OS and WO files.
