International Journal of Dentistry Table 2: Response details for NTRF usage according to specialty. Do not use NiTi Specialty Use NiTi (%)a (%)a Dental student 12 (38.7) 19 (61.3) General dentist 103 (52) 95 (48) AEGDb & Saudi board in 67 (97.1)∗∗ 2 (2.9) restorative dentistry Endodontist & Saudi 54 (91.5)∗∗ 5 (8.5) board in endodontics Other specialties 37 (75.5) 12 (24.5) Total 273 (67.2) 133 (32.8) a The percentage valued between parenthesis refers to each group, ∗∗(χ2 = 77.53, P < 0.001), bAdvanced Education in General Dentistry (AEGD). Table 3: Response details for NTRF and year of graduation. Participants who Use NiTi Do not use Years perform RCT (%)a NiTi (%)a 1971–1980 6 3 (50) 3 (50) 1981–1990 35 25 (71.4) 10 (28.6) 1991–2000 88 69 (78.4)∗ 19 (21.6) 2001–2010 277 176 (63.5) 101 (36.5) a The percentage valued between parenthesis refers to each group, ∗(χ2 = 7.80, P = 0.05). 3.4. Usage of NTRF in relation to Dental Specialties. Those participants who gave positive responses to the ﬁrst question were asked to proceed to the second question: “Do you use NTRF?” As shown in Table 2, of the total number of dentists performing RCT (n = 406), 67.2% (n = 273) were using NTRF at the time of the survey, and of 273 participants who used NTRF, 103 (37.7%) were general dentists. Interestingly, 97.1% of the participants in the AEGD and SBRD group were using NTRF, but this fell to only 91.5% in the Endodontists and Endodontic Residents group (χ2 = 77.53, P < 0.001). Conversely, 75.5% of all participants representing other dental professions (prosthodontists, peri- odontists, pedodontists, orthodontists, oral surgeons, and others) used NTRF whenever they performed RCT. 3.5. Usage of NTRF in relation to Clinical Experience. In this question (Table 3), participants were asked about their clinical experience and were then classiﬁed into ﬁve uniform classes, related to time of graduation, with each class span- ning 10 years. It was clearly shown that the majority (68.2%) of RCT was conducted by junior participants (2001–2010 group). Cross-tabulation was used between years of gradu- ation and use of NTRF. There was a signiﬁcant increase in NTRF usage with younger graduates, having less experience. The χ2 test was used to check dependency between clinical experience and use of NTRF. A signiﬁcant relationship (χ2 = 7.80, P = 0.05) was found between these two variables for those in the 1991–2000 graduation group. 3.6. Usage of NTRF in relation to Place of Graduation. Of the 406 dentists who reported performing RCT, almost half of 3 them had graduated in Saudi Arabia. The results showed that 145 (68.7%) of the Saudi graduates were using NTRF. All the participants (100%) who had graduated in Europe and Australia (n = 23) were NTRF users (P = 0.001). Of the 23 dentists who had graduated in North America 20 were NTRF users (P = 0.001), and of the 118 dentists who had graduated in Asia (primarily Syria, Lebanon), 66 (63.5%) were using NTRF. Conversely, those who had graduated in Africa used NTRF the least of all dentists surveyed. The diﬀerences between the proportions of those who did or did not use NTRF were statistically signiﬁcant when considering place of graduation (χ2 = 19.64, P = 0.001). 3.7. Gender Eﬀect. Table 5 shows that, of the 406 dentists performing RCT, 263 (65%) of them were male and 143 (35%) were female. There was a signiﬁcant eﬀect of gender on NTRF use; 73% of male dentists used these ﬁles versus only 56.2% of female dentists (χ2 = 11.26, P = 0.001). 3.8. Usage of NTRF in relation to Type of Practice. When respondents were asked about the type of practice in which they were working, it was found that 24% (n = 96) of those who were performing RCT were practicing at the Ministry of Health (Table 6). However, when we assessed each group independently, the highest usage of NTRF (n = 46, 93.9%) (P < 0.001) was observed at the Ministry of Defense Hospi- tals, followed by the Ministry of Interior Hospitals and the Ministry of National Guard Hospital (n = 11, 84.6%; n = 15, 88.2%; resp.). While an unexpected 55.8% (n = 48) of the participants practicing at the universities used NTRF, these ﬁles were used by 72% of the respondents from private hospitals and private dental clinics (n = 18 and n = 51; resp.). 3.9. Usage of NTRF in relation to Their Location. When the participants were asked about their current workplace location, 397 out of 406 dentists gave information regarding the city in which they were working. Only nine participants chose not to disclose this information. We divided the country into ﬁve regions according to the population. As expected, 47.3% of all participants who performed RCT were located in the central region (with the largest population) (Table 7). NTRF use was highest in the northern region (77.8%) although this ﬁnding was not signiﬁcant, second- highest in the central region (72.9%), and lowest in the eastern region (n = 43; 58.9%). 3.10. Reasons Preventing the Usage of NTRF. When partici- pants were asked about what may prevent them from using NTRF, they were permitted to choose more than one answer from a list of 11 possible reasons (Table 8). The group of participants who never used NTRF reported that the main reason for this was it “not being available” to them (64.7%, P ≤ 0.05). This was followed by “lack of experience” (54.1%, P ≤ 0.001) and “lack of knowledge or continuous education” (29.3%, P ≤ 0.05). Conversely, the group of participants who were using NTRF at the time of the survey reported that they are satisﬁed and that “there is no reason preventing