The resected root-end: is what you see what you get? A naked-eye, optical and SEM study
Aims: To determine the influence of bur types and vision aids on the detection of cracks, root filling deficiencies and anomalies in resected root ends and on the quality of root-end cavities and fillings. To determine the influence of the resected root surface on the quality of root-end fillings, under different optical conditions. Method: In this three-part study, 48 human teeth were prepared using ProTaper™ files (Dentsply) and filled with matching gutta percha (GP) cones and AH Plus sealer (Dentsply). In Part 1, half were resected 3 mm from the apex using a low-speed tungsten carbide (TC) surgical bur (H33L, Komet, Brasseler, Germany) and the rest with a high-speed bur (H162, Komet). Twelve specimens from each group were then polished (H135UF, Komet). In Part 2, root-end cavities were prepared in all teeth using ProUltra® surgical tip, SURG 2 (Dentsply), powered by Satelec P5 Newtron® ultrasonic unit (Acteon, Merignac, France). In Part 3, the teeth were filled with either Super-EBA or Mineral Trioxide Aggregate. On completion of each stage, the root ends were examined by three endodontists, with the naked eye, loupes (x3.25) and a dental operating microscope (DOM, x31). Silicone impressions were made at each stage to produce epoxy resin replicas for scanning electron microscopy (SEM), x25. In each part, three examiners used a designated scoring sheet and examined the teeth together to reach a consensus. Regression analyses were performed on the data. Results: In Part 1, there was an odds ratio of one between DOM and SEM in scoring surface roughness; however, these were not all in the same teeth. No cracks were observed with naked eye or loupes, but five were seen with DOM. Two cracks identified with DOM were not seen on SEM. A total of thirteen cracks were detected in seven teeth by SEM. Under SEM, fourteen root canal filling deficiencies were found and under DOM eight deficiencies noted, but only two were in the same teeth. Under loupes and naked eye, six deficiencies were found and under DOM, one anomaly was seen by DOM but not identified by SEM. In Part 2, false positives and negatives were found with all three optical methods when assessing cracks and the presence of GP at the cavity margin. All optical systems allowed detection of fewer cracks than SEM. In Part 3, there was no significant difference in crack identification between DOM and loupes and both were marginally better than the naked eye. None of the optical methods, when compared to SEM, reliably reported the surface roughness of the root-end filling, the presence of marginal discrepancy or the level of filling compared to the SEM. There was no influence of resection bur combination on the ability to describe the quality of root-end fillings under different optical parameters. Conclusions: Loupes or the DOM may result in the false identification of cracks, anomalies, root filling deficiencies and detection of GP at the cavity margin. The usefulness of the DOM and loupes when describing the quality of root-end cavities and fillings appears to be somewhat limited. Factors other than magnification require further evaluation.
Advisor: Chandler, Nicolas Paul; Herbison, Peter; Friedlander, Lara
Degree Name: Doctor of Clinical Dentistry
Degree Discipline: Oral Rehabilitation
Publisher: University of Otago
Keywords: apicectomy; apical; surgery; root-ends
Research Type: Thesis