本文選題：牙髓腔　切入點(diǎn)：不銹鋼　出處：《中國(guó)組織工程研究》2017年26期

【摘要】：背景:根管器械折斷是一種比較常見(jiàn)的口腔臨床并發(fā)癥,因此,研究不同型號(hào)不銹鋼根管銼的循環(huán)疲勞性能,具有重要的臨床意義。目的:探討根管彎曲角度及根管器械橫截面積變化對(duì)不銹鋼根管器械循環(huán)疲勞性能的影響。方法:選取25#、30#、35#不銹鋼K銼(長(zhǎng)25 mm,錐度相同)各30支,每種型號(hào)隨機(jī)分為3組,共9組,這9組分別置于彎曲角度為45°,60°,90°的自制人工模擬彎曲根管中,用16∶1減速手機(jī)(350 r/min)驅(qū)動(dòng)不銹鋼K銼。記錄每組器械折斷所需時(shí)間,將時(shí)間轉(zhuǎn)換為轉(zhuǎn)數(shù),采用掃描電鏡分析折斷K銼斷口的顯微結(jié)構(gòu),收集循環(huán)疲勞性能實(shí)驗(yàn)中折斷的器械,電子游標(biāo)卡尺測(cè)量斷尖長(zhǎng)度。結(jié)果與結(jié)論:(1)在彎曲角度相同的情況下,隨著器械橫截面積的增大,器械折斷所旋轉(zhuǎn)的周期數(shù)明顯減少(P0.05)。在型號(hào)相同、橫截面積相同的情況下,隨著根管彎曲角度的增加,器械折斷所旋轉(zhuǎn)的周期數(shù)明顯減少(P0.05),器械的循環(huán)疲勞性能明顯下降;(2)各組不銹鋼銼的斷口均為韌性斷口,斷口表面可見(jiàn)一些大小不等的圓形或橢圓形韌窩并存在微觀空洞,韌窩間可見(jiàn)延晶斷裂的脆性斷面。隨著根管彎曲角度增大,韌窩直徑逐漸增大。在30#、35#不銹鋼K銼斷口形貌中,隨模擬根管彎曲角度增加,脆性斷面有逐漸增加的趨勢(shì);(3)對(duì)于25#不銹鋼K型銼,隨著根管彎曲角度的增加,器械折斷的斷尖長(zhǎng)度逐漸減小,但變化不明顯(P0.05)。對(duì)于#30,#35不銹鋼K型銼,隨著根管彎曲角度的增加,器械折斷的斷尖長(zhǎng)度逐漸減小(P0.05),其中#35-60°組與#35-90°組變化呈下降趨勢(shì)但變化不明顯(P=0.095)。在根管彎曲角度相同的情況下,隨著不銹鋼器械型號(hào)的增加,器械折斷的斷尖長(zhǎng)度變化沒(méi)有規(guī)律;(4)結(jié)果表明,不銹鋼K型根管銼在長(zhǎng)度和錐度相同的條件下,橫截面積越大根管器械的循環(huán)疲勞性能越低,器械越容易折斷;相同型號(hào)的不銹鋼K型銼,隨著根管彎曲角度增大,折斷位置越靠近根尖部位,即斷尖長(zhǎng)度越短,斷針取出越困難。
[Abstract]:Background: fracture of root canal instruments is a common oral clinical complication. Therefore, it is of great clinical significance to study the cyclic fatigue properties of stainless steel root canal files of different models.Objective: to investigate the effects of root canal bending angle and cross-sectional area of root canal instruments on the cyclic fatigue properties of stainless steel root canal instruments.Methods: 30 stainless steel K files (25mm long, with the same taper) were selected for 25 #CU. Each model was randomly divided into 3 groups and 9 groups. The 9 groups were placed in a self-made artificial curved root canal with a bending angle of 45 擄, 60 擄and 90 擄, respectively.Drive stainless steel K file with 16:1 deceleration phone 350 r / min.The time required for fracture of each group of instruments was recorded and converted to rotational number. The microstructures of broken K files were analyzed by scanning electron microscope (SEM). The broken instruments in cyclic fatigue test were collected and the length of broken tip was measured by electronic Vernier caliper.Results and conclusion 1) under the same bending angle, with the increase of the cross section area of the apparatus, the number of rotated cycles decreased obviously.In the case of the same type and same cross-sectional area, with the increase of the root canal bending angle, the number of rotated cycles of the instrument breaking is significantly reduced, and the cyclic fatigue property of the apparatus is obviously decreased. (2) the fracture surfaces of the stainless steel files in each group are all ductile fractures.There are some round or elliptical dimples with different sizes on the surface of the fracture surface, and there are microvoids, and brittle sections of the ductile fracture can be seen between the dimples.The dimple diameter increases with the increase of root canal bending angle.In the fracture morphology of 30#CU 3 stainless steel K file, with the increase of simulated root canal bending angle, the brittle cross section gradually increased. For 25 # stainless steel K file, with the increase of root canal bending angle, the broken tip length of the instrument gradually decreased.But the change was not obvious (P 0.05).For the #30 / #35 stainless steel K file, with the increase of the root canal bending angle, the broken tip length of the apparatus decreased gradually, and the changes of #35-60 擄group and #35-90 擄group showed a downward trend, but the change was not obvious in #35-60 擄group and #35-90 擄group.When the root canal bending angle is the same, with the increase of stainless steel instrument type, the length of broken tip of the broken instrument does not change regularly (4) the result shows that the stainless steel K type root canal file has the same length and taper under the condition of the same length and taper.The larger the cross-sectional area, the lower the cyclic fatigue performance of the root canal instruments, and the easier the apparatus to break; the same type of stainless steel K file, with the increase of the root canal bending angle, the more close the fracture position is to the root tip, that is, the shorter the length of the broken tip,The more difficult it is to take out the broken needle.
【作者單位】： 天津醫(yī)科大學(xué)口腔醫(yī)院綜合科;北京通州區(qū)新華醫(yī)院口腔科;
【基金】：天津醫(yī)科大學(xué)口腔醫(yī)院科研基金(2013yky02)~~
【分類號(hào)】：R781.05
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本文編號(hào)：1702723