Delano E O, Ludlow J B, Ørstavik D, Tyndall D, Trope M
Diagnostic Sciences and General Dentistry Department, University of North Carolina, Chapel Hill, NC 27599, USA.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2001 Jul;92(1):108-15. doi: 10.1067/moe.2001.115466.
The purpose of this study was to compare both subjective (Periapical Index, PAI) and objective (densitometric) radiographic evaluation of healing after endodontic treatment for apical periodontitis.
Standardized radiographs of 103 teeth taken at baseline (immediately after endodontic treatment) and at 1, 4, 12, 26, and 52 weeks were evaluated. Consensus PAI scores obtained from 7 calibrated observers served as "true scores." Densitometric estimates of periapical status were obtained from digitized radiographs as the ratio of mean gray value of an area of radiolucency (AR) to an adjacent and similar-sized normal (N) area (AR/N). The selected regions of interest on baseline images were automatically superimposed on postoperative images. All estimates of change were measured with respect to baseline. The subtraction estimate was expressed as AR(S)-N(S). Linear regression was used to analyze longitudinal changes against baseline and to assess the relationship of PAI and AR/N and of change in PAI with respect to baseline and AR(S)-N(S).
Five hundred fifty-six PAI scores were generated, with 547 AR/N values and 444 subtraction estimates. PAI, AR/N, and AR(S)-N(S) demonstrated statistical significance for change (P < or = .05) starting at 12 weeks. PAI was significantly correlated with AR/N (P < .0001), as was CHPAI with AR(S)-N(S) (P < .024).
The PAI and 2 densitometric estimates (AR/N and AR(S)-N(S)) detected healing of apical periodontitis at 12 weeks after treatment. No difference could be observed among the methods.
本研究旨在比较根尖周炎根管治疗后愈合情况的主观（根尖指数，PAI）和客观（密度测定）影像学评估。
对103颗牙齿在基线（根管治疗后即刻）以及1、4、12、26和52周时拍摄的标准化X线片进行评估。由7名经过校准的观察者获得的一致PAI评分作为“真实评分”。根尖周状况的密度测定估计值从数字化X线片中获得，即透射区（AR）面积与相邻且大小相似的正常（N）区域的平均灰度值之比（AR/N）。基线图像上选定的感兴趣区域自动叠加在术后图像上。所有变化估计值均相对于基线进行测量。减法估计值表示为AR(S)-N(S)。采用线性回归分析相对于基线的纵向变化，并评估PAI与AR/N以及PAI相对于基线和AR(S)-N(S)的变化之间的关系。
共生成556个PAI评分、547个AR/N值和444个减法估计值。PAI、AR/N和AR(S)-N(S)从12周开始显示出变化的统计学意义（P≤0.05）。PAI与AR/N显著相关（P<0.0001），CHPAI与AR(S)-N(S)也显著相关（P<0.024）。
PAI和两种密度测定估计值（AR/N和AR(S)-N(S)）在治疗后12周时检测到根尖周炎的愈合。各方法之间未观察到差异。
