Mechanical Characteristics, Testing, and Future Perspective of Nickel-Titanium Rotary Instruments.

The main drawback of several studies is the limited analysis performed for the comparison of nickel-titanium (NiTi) rotary systems. Most often, research articles in this area are focalized on the static characteristics such as static cyclic fatigue, torsional loads, and flexibility, not considering their reciprocal interaction and all dynamic factors.1 Recent evidence in the literature defines the reciprocal interaction between these parameters as a fundamental element in the study of their mechanical characteristics.2 However, static mechanical behavior is fundamental to assess the basic performance of NiTi instruments, but its interpretation during clinical practice is pointless as it does not resemble the real clinical scenario.1,3,4 Results arising from static tests, certainly valid as a first approach to the evaluation of an instrument recently introduced on the market, and comparative evaluations, should be considered in a general and more complete view, considering their reciprocal relationships.3-6 For these reasons, different types of researches that investigate both static and dynamic performance of NiTi instruments should be strongly recommended in order to give to original research and in vitro study an actual clinical significance, certainly much more indicative in view of a subsequent clinical application of NiTi rotary instruments.7-9.

Operative Torque Analysis to Evaluate Cutting Efficiency of Two Nickel-Titanium Rotary Instruments for Glide Path: An In Vitro Comparison.

AIM AND OBJECTIVE: The aim and objective of this study was to evaluate and compare the cutting efficacy of two different nickel titanium rotary instruments by a novel methodology: the operative torque (torque and time needed to progress toward the apex). MATERIALS AND METHODS: Ten fresh extracted upper first premolars with two canals were instrumented with a KaVo (Biberach, Germany) and a KaVo 1:1 handpiece at 300 rpm with maximum torque set at 2 N. One canal was instrumented with ProGlider NiTi rotary instruments (Dentsply Sirona Endodontics, Ballaigues, Switzerland), with tip size of 16.02, and the other one with EgdeGlidePath rotary instrument (EdgeEndo, Albuquerque, New Mexico). Mean instrumentation time, mean torque values, and maximum torque values were evaluated for each instrument. The significance level was set at p <0.05. RESULTS: EdgeGlidePath instruments reached the working length in significantly less time with a significantly smaller amount of torque when compared to ProGlider (p >0.05). No instruments exhibited flute deformation or underwent intracanal failure. CONCLUSIONS: Operative torque is related to the capability to cut dentin and progress toward the apex: the smaller the torque values, the higher the cutting ability (and safety). Operative torque is also dependent on debris removal and irrigation techniques. Nevertheless, both operative torque and instrumentation time are clinically relevant parameters for evaluating instruments' performance (i.e., cutting ability). CLINICAL SIGNIFICANCE: Operative torque during endodontic instrumentation helps understanding the overall performance in terms of both cutting efficiency and safety.

New Strategies and Instruments for Root Canal Shaping Procedure: An Overview.

Cone-beam computed tomography-based three-dimensional analysis of root canal trajectories and shapes have clearly shown that root canals are more complex in 3D, compared to traditional 2D visualization,1-4 and consequently, these findings affect properties of the nickel-titanium (NiTi) files requiring the following factors.

Academic Dental Activities and COVID-19 Pandemic.

COVID-19 pandemic has strongly and rapidly affected routine lifestyle and consequently, dental business, practice, and education. During the pandemic period, most Governments worldwide made specific regulations or recommendations to close practices, to avoid non-urgent dental therapies and treat only dental emergencies. Some recent surveys1,2 showed how dentists perceived the COVID-19 risk and how they reacted: by modifying their way of working, by reducing aerosol producing procedures, by improving staff and patient's safety with the increased use of personal protective equipment, environmental disinfection and limited access to dental offices, increasing use of remote consulting and triage.

Fine Aerosols and Perceived Risk of COVID-19 among Italian Dental Practitioners: An Experimental Survey.

AIM: The aim of the present study was to take a survey on Italian practitioners concerning the perceived risks of aerosol contamination in COVID-19 times and their attitude toward modifications of treatment protocols to reduce this risk. MATERIALS AND METHODS: Power analysis calculated a minimum sample size of 150 participants at 99% confidence level with a 5% margin of error. To homogenize responses elicited by different preventive measures by various national governments, only Italian dentists were included in the survey: overall 500 responses were collected. RESULTS: Of the 500 analyzed respondents, there were 266 females and 234 males; 379 practitioners were allocated in the more experienced groups, and the remaining 121 in the less experienced group based on less or more than 5 years of practice. The 70% of the dentists consider the dental practice more dangerous for the diffusion of COVID-19 than other social activities. The 5% consider dental practice more dangerous only for the patients. Aerosol contamination was perceived as a risk from the most dentist (70%), but there was agreement on the most dangerous way of cross infection in dental settings. Most of the dentists (55%) believed implementations in their protocols were needed to reduce the risk of COVID-19 infections. No significant differences were found within the groups: both women and men, as well as practitioners with different experience levels (younger or older than 35 years) perceived very similarly the problems related to COVID-19 in dentistry (p > 0.05). CONCLUSION: The survey demonstrated that COVID-19 had a great impact on dental practitioners; it increased not only fear of aerosol contamination during dental treatments but also influenced the fear of close contacts. SIGNIFICANCE: Airborne and waterborne infections are related with dental treatments and considered the preferred ways of diffusion for COVID-19. The risk of aerosol-related infections could interfere with the clinical practice of the dentist, during the COVID-19 pandemic; the limitations that provided changes to everyday behavior could affect the perception of the safety of the operators, staff, and patient and this could also affect economically the dental office.