The use of cone beam computed tomography by brazilian endodontists: A questionnaire-based survey.

Background: This study aimed to assess the knowledge of Brazilian endodontists regarding the use of cone beam computed tomography (CBCT) in endodontic therapy. Material and Methods: An invitation to participate in the research was sent to 3256 professionals through class groups on social networks and via email. Participants answered an online questionnaire consisting of 11 questions about the clinical situations in which they used CBCT and whether they had any knowledge of the technical protocols such as parameters of field of view (FOV) and voxels of the CBCT equipment. The questionnaire was answered by 742 endodontists who represented 22.7% of the invited professionals. Results: The data obtained indicate that 76.7% of the participants use or have used CBCT during endodontic treatments. The most often reported clinical conditions for using the CBCT were: root fractures (64%), locating the canals (58.7%), perforations (53.9%), and root resorption (42.1%). More than 60% of the participants stated that they do not have information about the voxel, FOV, and the CBCT system used in their requests. Only 34.1% reported using CBCT to the performed endodontic treatments follow-up. Conclusions: CBCT was a tool widely utilized by the participants, with root fracture being the clinical condition with the highest indication for CBCT. Many professionals were unaware of the technical protocol used in the exams. Key words:Endodontics, Cone Beam Computed Tomography, Endodontic Therapy.

Torsional fatigue strength of reciprocating and rotary pathfinding instruments manufactured from different NiTi alloys.

To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.

Torsional fatigue strength of reciprocating and rotary pathfinding instruments manufactured from different NiTi alloys

Abstract To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.

Nickel-titanium instruments in endodontics: a concise review of the state of the art.

The introduction of automated instrumentation in endodontics represented a major advance in progress for this specialty, with improvements in the quality and predictability of root canal preparation and a significant reduction in procedural errors. In recent years, endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments. In addition, new movements have also been incorporated to offer greater safety and efficiency, optimizing the properties of the NiTi alloy, especially through eccentric rotary motion. An understanding of the mechanical properties of these new NiTi instruments and their effect on the clinical performance of root canal preparation is essential if dental practitioners are to select the instruments that provide optimal clinical outcomes, especially in curved or flattened canals. The objective of this literature review is to present and discuss the characteristics of the NiTi alloys used in the major instrumentation systems available in the market, as well as the influence of the metallurgical and mechanical properties of NiTi instruments and the movements that drive them, to enable more accurate and predictable planning of root canal preparation.

Analysis of apical sealing of canals irradiated with Er: YAG and Nd: YAG lasers and filled with AH Plus®

Introduction: Laser technology is gaining increasing importance in dental practice and also in the field of Endodontics with its ability to promote disinfection and experimentally in the preparation of root canal. The action of different types of lasers results in changes representing the increase in permeability of dentinal tissue (Er: YAG) or sometimes by a decrease in melting and recrystallization of dentin (Nd: YAG). Objective: this study assessed through apical dye leakage, the influence of irradiation with two types of laser, regarding to the quality of apical sealing of endodontic fillings. Material and methods: Thirty-six single-rooted teeth were used after being prepared with the ProFile system up to size #40 instrument and then divided into four experimental and two control groups. The technique used previously to the filling was as follows: G1 - not irradiated; G2 - irradiated with Er: YAG; G3 - irradiated with Nd: YAG and G4 - irradiated with Er: YAG followed by Nd: YAG. After external waterproofing and dry, the specimens were filled with a cold vertical condensation technique, using AH Plus sealer, and immediately immersed into 0.5% methylene blue solution for subsequent cleavage. The linear values of apical marginal leakage were obtained with the aid of an optical microscope connected to a computer using the Image Lab® software. Results: Data analysis showed the non-existence of statistically significant (p = 0.05) differences between different groups. Conclusion: It was concluded that the laser does not have influence on the apical sealing.