Yılmaz Ayça, Gökyay Sıtkı Selçuk, Dağlaroğlu Rüştü, Küçükay Işıl Karagöz
Department of Endodontics, İstanbul University Faculty of Dentistry, İstanbul, Turkey.
Department of Endodontics, Okan University Faculty of Dentistry, İstanbul, Turkey.
Eur Oral Res. 2018 May;52(2):89-93. doi: 10.26650/eor.2018.461. Epub 2018 May 1.
To evaluate the deformation and fracture rates for ProTaper Universal (PTU) nickel-titanium rotary instruments according to the frequency of clinical use.
A total of 619 PTU instruments (S1, S2, F1, F2, and F3) that have been used in the clinic by a single endodontist were collected over a period of 4 years. These instruments were grouped on the basis of one to three (Group A), four to six (Group B) and seven to nine (Group C) clinical uses (one canal = one use). All instruments were evaluated by a blinded investigator under a stereomicroscope at 15×-45× magnification for the presence of deformation and fracture.
The overall rates of deformation and fracture were 10% and 1.2%, respectively. The deformation and fracture rates for the S2, F1, and F2 instruments showed no significant differences among groups. However, fracture rate for S1 instruments in Group A was significantly higher than for those in Group B (p=0.025) and Group C (p=0.004). In Group C, the S1 instruments showed a significantly higher deformation rate compared with the S2 (p=0.04), F1 (p=0.008) and F2 (p=0.049) instruments; there were no other significant differences within groups.
Under the conditions of the current study, frequency of use seemed to influence the deformation rates of PTU rotary instruments. Except S1, these instruments could be used without any fracture or deformation in up to 9 clinical cases by an experienced endodontist.
根据临床使用频率评估ProTaper Universal（PTU）镍钛旋转器械的变形率和折断率。
在4年的时间里，收集了由一位牙髓病医生在临床使用过的619支PTU器械（S1、S2、F1、F2和F3）。这些器械根据一至三次（A组）、四至六次（B组）和七至九次（C组）临床使用情况（治疗一个根管为一次使用）进行分组。所有器械均由一位不知情的研究者在体视显微镜下以15× - 45×放大倍数评估是否存在变形和折断情况。
总体变形率和折断率分别为10%和1.2%。S2、F1和F2器械的变形率和折断率在各组间无显著差异。然而，A组中S1器械的折断率显著高于B组（p = 0.025）和C组（p = 0.004）。在C组中，S1器械的变形率显著高于S2（p = 0.04）、F1（p = 0.008）和F2（p = 0.049）器械；各组内无其他显著差异。
在本研究条件下，使用频率似乎会影响PTU旋转器械的变形率。除S1外，经验丰富的牙髓病医生在多达9例临床病例中使用这些器械时不会出现任何折断或变形情况。
