RESUMO
Purpose: Postoperative pain is a common complication in endodontics contributed by multiple etiological factors, which consist canal preparation instruments and kinematics. The aim of this randomized clinical trial compare the postoperative pain in terms of intensity and incidence after the use of different nickel titanium (NiTi) file systems. Patients and methods: In this randomized clinical trial (NCT03791762), a total of 150 patients were root canal treated by 2 experienced endodontists according to a standardised protocol. The subjects were randomly assigned to 1 of the 3 groups according to preparation instrument used: ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland), Reciproc Blue (VDW, Munich, Germany) and WaveOne Gold (Dentsply Sirona). Following preparation the teeth underwent standardized root canal treatment procedures in a single visit. The patients were contacted to gather information about the incidence of pain and intensity at 6th, 12th, 18th, 24th, 48th, and 72nd hours postoperatively. The data were analysed using chi-square, one-way analysis of variance and post hoc Tukey tests and logistic regression analysis with 5% significance threshold. Results: No significant difference was found among preparation groups in relation to the intensity of postoperative pain. The incidence of postoperative pain was significantly linked with the preoperative pain presence with odds ratio values ranging between 2.06 and 4.08 irrespective of the preparation technique (P<0.05). Conclusion: The effects of reciprocating and the continuous rotary systems on the intensity and incidence of postoperative pain were found to be similar.
RESUMO
AIM: This in vitro study was conducted to compare the fracture strength of endocrowns manufactured from different hybrid blocks under axial and lateral forces. MATERIAL AND METHODS: Following root-canal treatment, 100 permanent mandibular first molars were randomly distributed among 5 groups according to restoration material. Endocrown restorations were produced from IPS e.max CAD (IPS), Vita Enamic (VE), GC Cerasmart (GC), Shofu (SH), and Brilliant Crios (BC) using CAD/CAM technology. Specimens were cemented, subjected to artificial aging, and further divided into 2 subgroups (n = 10) per group for fracture testing. Each specimen was placed on a universal testing machine and subjected to axial or lateral forces applied at a crosshead speed of 1 mm/min. Fracture data were analyzed using one-way ANOVA, Tukey, Tamhane T2, and Weibull tests. RESULTS: Statistically significant differences in fracture-strength (FS) values under axial and lateral forces were observed among the groups (P < 0.05). Group BC had the highest FS value under axial forces, whereas group IPS had the highest FS value under lateral forces. According to Weibull analysis, VE exhibited the highest reliability under axial forces (7.62), whereas IPS exhibited the highest reliability under lateral forces (4.68). No statistically significant differences were detected in the distribution of failure types under either axial or lateral forces among the groups (P > 0.05). CONCLUSION: All of the hybrid blocks tested showed sufficient fracture strength for use as CAD/CAM-fabricated endocrowns. CLINICAL RELEVANCE: Hybrid blocks can be used as an alternative to lithium disilicate blocks in endocrown restorations.