A laboratory study of the accuracy of three electronic apex locators: influence of embedding media and radiographic assessment of the electronic apical limit

AIM

To evaluate several factors that might interfere with the use of electronic root canal length measurement devices (ERCLMDs) in a laboratory setting, including two different embedding media (alginate and electroconductive gel), three different types of devices and the radiographic view on the assessment of the electronic readings.

METHODOLOGY

Thirty single-rooted extracted human mandibular premolars were selected. After access and canal pre-flaring, a size 10 K-file was inserted in the canal up to the major apical foramen under magnification (×10), and this length was recorded as the actual length (AL) of the canal. Teeth were mounted on a specific endodontic training kit platform (ProTrain). Two different embedding media (electroconductive gel and alginate) and three different ERCLMDs: Apex ID (SybronEndo, Glendora, CA, USA), CanalPro Apex Locator (Coltene-Endo, Cuyahoga Falls, OH, USA) and the Root ZX II (J. Morita, Tokyo, Japan), were tested. Following the measurement at the 0.5 mark of each ERCLMD using alginate, two periapical radiographs (bucco-lingual and proximal views) were taken. The difference between the electronic readings and the AL, as well as the distance from the file tip to the apex of the roots on the radiographs, was calculated. Data were analysed statistically (two-way anova, Tukey's and chi-squared tests) at 5% significance level.

RESULTS

The incidence of over-extended readings was significantly greater (P < 0.05) when using the ProTrain electroconductive gel, except for Root ZX II at the 0.5 mark. Root ZX, CanalPro and Apex ID had similar accuracy when the 0.0/APEX mark was used to locate the foramen. For the radiographic method, no difference was found between the devices or radiographic views.

CONCLUSION

Compared with alginate, the conductive gel of the ProTrain kit negatively affected most of the electronic readings. The three evaluated ERCLMDs had similar accuracy in locating the apical foramen when using the mark 0.0/APEX and alginate as the embedding media. Although the ProTrain platform allows radiographs to be exposed in both bucco-lingual and proximal views, no difference was found between the views when evaluating the apical limit provided by the 0.5 mark in mandibular premolars embedded in alginate.

Spontaneous Resolution of a Central Giant Cell Granuloma in a Child After an Incisional Biopsy: A Five-year Follow-up

A central giant cell granuloma (CGCG) is typically regarded as a benign lesion with osteoclastic activity. Treatment often involves surgical procedures that may cause deformities; however, minimally invasive approaches have been suggested for treating pediatric patients. We report a case of CGCG of the mandible in a 13-year-old boy who presented with a well-defined radiolucent area in the anterior mandible that was initially detected in a radiographic examination for orthodontic purposes. An incisional biopsy was performed and diagnosed histologically as a CGCG. The patient underwent clinical and radiographic follow-up only after the biopsy, eventually showing signs of bone healing. Five years later, complete resolution of the lesion was observed radiographically. Considering this optimal outcome, similar cases of CGCG should be carefully analyzed for appropriateness of this conservative approach.