Pintado M R, Delong R, Ko C C, Sakaguchi R L, Douglas W H
University of Minnesota, Minneapolis, Minn., USA.
J Prosthet Dent. 2000 Oct;84(4):436-43. doi: 10.1067/mpr.2000.109477.
Noncarious cervical lesions are described as having a multifactorial cause, with occlusal trauma and toothbrush abrasion frequently mentioned as major factors. Finite element modeling studies have demonstrated a relocalization of occlusal stresses to the cervical area due to flexure of the crown. This may cause microcracking, especially under tensile stresses, that will lead to a loss of enamel and dentin in the cervical region. Clinical confirmation of an occlusal cause for noncarious cervical lesions has been difficult to obtain.
This study investigated whether occlusal wear was correlated with an increase in the size of noncarious cervical lesions.
Loss of contour at occlusal and cervical sites on 3 teeth of a single individual was measured using digital and visualization techniques at 3 time intervals over a 14-year time span. The 1983 baseline casts and 1991, 1994, and 1997 clinical impressions of a single adult patient with existing noncarious cervical lesions were replicated in epoxy. Surfaces of all replicas were digitized with a contact digitizing system. Sequential digitized surfaces were fit together and analyzed using AnSur-NT surface analysis software. Clinical losses of surface contour by volume and depth of the left mandibular first molar and first and second premolars were recorded.
Nine measurements of cervical volume loss (range 0.9 to 11.5 mm(3)) and 9 corresponding measurements of occlusal volume loss (range 0.39 to 7.79 mm(3)) were made. The correlation between occlusal and cervical volume loss was strong (r(2)=0.98) and significant (P<.0001).
For the single adult patient in this study, there was a direct correlation between occlusal wear and the growth of noncarious cervical lesions.
非龋性颈部病变被认为是由多种因素引起的,其中咬合创伤和牙刷磨损常被提及为主要因素。有限元建模研究表明,由于牙冠弯曲,咬合应力会重新分布到颈部区域。这可能导致微裂纹,特别是在拉应力作用下,进而导致颈部区域的釉质和牙本质丧失。很难获得非龋性颈部病变咬合原因的临床证实。
本研究调查咬合磨损是否与非龋性颈部病变大小的增加相关。
在14年的时间跨度内,使用数字和可视化技术,在3个时间间隔对单个个体的3颗牙齿的咬合面和颈部的轮廓丧失情况进行测量。对一名患有现有非龋性颈部病变的成年患者的1983年基线模型以及1991年、1994年和1997年的临床印模用环氧树脂进行复制。所有复制模型的表面用接触式数字化系统进行数字化处理。将连续的数字化表面拟合在一起,并使用AnSur-NT表面分析软件进行分析。记录左下颌第一磨牙以及第一和第二前磨牙表面轮廓在体积和深度方面的临床丧失情况。
进行了9次颈部体积丧失测量(范围为0.9至11.5立方毫米)和9次相应的咬合面体积丧失测量(范围为0.39至7.79立方毫米)。咬合面和颈部体积丧失之间的相关性很强(r² = 0.98)且具有统计学意义(P <.0001)。
对于本研究中的成年患者,咬合磨损与非龋性颈部病变的发展之间存在直接相关性。