Assessment of Distortion of Radiovisiographical Tooth Length Compared to Actual Tooth Length: In-vivo and In-vitro Study

Abstract

Background: Determination of appropriate or exact working length measurement with radiovisiography (RVG) during root canal treatment (RCT) is an essential for the long-term success. As, there are several controversies with the distortion of RVG image in assessing the working tooth length (WTL) during RCT compared to actual tooth length (ATL). So, this study was aimed to assess the frequency of distortion of radiovisiographical tooth length (RTL) compared to actual tooth length (ATL). Methods: An analytical (in-vivo and in-vitro) study was conducted at Department of Conservative Dentistry and Endodontics, BSMMU. The patient indicated for extraction purpose of orthodontic treatment was considered as the study population. Human premolar teeth (n=20) were selected as study sample by purposive sampling technique which met the inclusion and exclusion criteria. The RTL measurements were carried out with RVG images before and after tooth extraction (in-vivo and in-vitro setting). Then the ATL measurements of extracted tooth samples were carried out with both Inch Architectural Scale Ruler and Endodontic Ruler individually three concordant times. Statistical analysis: The data was analyzed using T test and presented in frequency and percentages with tables. Results: For 95% of study samples, the differences from actual and radiovisiographical tooth length were <0.5 mm. Total 19 tooth samples (out of 20) showed acceptable level of coincidence except one sample showed non-acceptable level of coincidence. There was no sample revealed exact level of coincidence. There was a significant difference between the distortion category; yes (95%)/ no (5%) (P 0.001). The radiovisiological tooth lengths among all samples were same in both in-vivo and in-vitro setting. Study results also revealed the average distortion of RTL to ATL was 2.61±0.97 mm when RVG was done without using RVG sensor positioner. Conclusion: RVG tooth length images exhibited no distortion with the exact anatomical tooth lengths when the RTL was carried out with RVG sensor positioner. It’s recommended that to overcome the RVG image distortion, the RTL measurement ought to be carried out with RVG sensor positioner allowing RVG sensor/film parallel to long axis of tooth; RVG beam position perpendicular (900) to long axis of tooth.