Micro-CT evaluation of a novel periodontal ligament simulation technique for dental experimental models

A reliable technique for simulation of the periodontal ligament (PDL) is required for in vitro studies. This paper proposes a simple technique to construct a tooth-PDL-bone experimental model with a reproducible PDL layer of a uniform width. In a preliminary study, two PDL simulation techniques were compared; transitional wax technique: wax layer was used to create a space for the PDL simulating material (light-body silicon) and direct rubber application technique: PDL simulating material (rubber die-spacer) was painted directly on the root surface. In both techniques, teeth were mounted in acrylic resin to simulate the supporting bone. The tooth-PDL-bone models were scanned using SkyScan 1076 micro-CT scanner and PDL-layer width was measured at selected sites on the roots using CTAn software. Based on the results of the preliminary study, 10 experimental models were constructed using the direct rubber application technique to confirm the reproducibility and consistency of the PDL layer width using micro-CT. Intra-class correlation coefficients (ICC) were calculated to assess the reproducibility. The transitional wax technique showed significantly greater variability in the PDL layer width when compared with the direct rubber application technique (F=66.0, p<0.001). The direct rubber application technique showed excellent reproducibility (ICC= 0.94; 95% confidence interval: 0.86, 0.98).