A Critical Review of Methods for Quantitative Evaluation of Root Canal Transportation

A novel computer‐aided method for direct measurements and visualization of gingival margin changes

“…For feasibility reasons, the conventional approach evaluates GM changes only at six sites per tooth, neglecting a considerable amount of available data. In general, evaluation at a limited number of sites was reported to be at high risk of missing local maximal values, as was recently pointed out in the critical review of root canal transportation methods (Fidler et al, 2021). Exploiting all available data by evaluation and visualization of GM changes along the whole length of GM reveals a similar situation, as the local maximum values do not always correspond to conventional measurement (Figure 6 and 7c), and such observation might warrant future research.…”

A critical appraisal of research methods and experimental models for studies on root canal preparation

“…centring ratio [Calhoun & Montgomery, 1988; Gambill et al, 1996; Glossen et al, 1995; Short et al, 1997; Silva et al, 2017]). For detailed information on differences in mathematical and geometrical details of transportation studies and ratio calculations the reader is referred to the critical review by Fidler and co‐workers (Fidler et al, 2021).…”

“…There appears to be no investigation evaluating and comparing the quality of study designs used in transportation studies in terms of exactness, reproducibility, and possible covariates. In a recent review, comprising 74 publications on root canal transportation, Fidler et al (2021) demonstrated that due to non-standardised evaluation methods comparison of respective studies is difficult. Especially, ratio parameters seem to be unsuitable to quantify transportation, displacement of the canal centre point from a mathematical point of view provides the most exact data on transportation (mathematically more exactly termed translation) of the root canal axis (Fidler et al, 2021).…”

“…In a recent review, comprising 74 publications on root canal transportation, Fidler et al (2021) demonstrated that due to non-standardised evaluation methods comparison of respective studies is difficult. Especially, ratio parameters seem to be unsuitable to quantify transportation, displacement of the canal centre point from a mathematical point of view provides the most exact data on transportation (mathematically more exactly termed translation) of the root canal axis (Fidler et al, 2021). The authors underlined the need of standardised root canal anatomy for comparative studies on transportation and suggest the use of plastic canals.…”

“…Among the transportation studies published in endodontic journals, there is no homogeneity and comparability in terms of selection and standardisation of teeth, evaluation technique, and parameters of measurement (Fidler et al, 2021; Schäfer & Bürklein, 2013). Transportation can be determined evaluating two‐dimensional images (radiographs, microscopic evaluation of horizontal root sections) or 3‐D scans using CBCT or micro‐CT with the latter being superior due its better resolution (76–400 µm vs. 17–40 µm) and in the longitudinal or in the horizontal plane.…”