Ex-vivo and in-vivo validation of a novel measuring protocol for guided endodontics

OBJECTIVES

To (1) validate the use of a post-operative intraoral scan (IOS) versus Cone Beam Computed Tomography (CBCT), gold standard, on its ability to measure the accuracy of guided endodontics, and (2) present clinical data on the accuracy of guided endodontics.

METHODS

Four models, including 10 extracted teeth each, were created. Forty guided access cavities were planned on dentin to simulate pulp canal obliteration (PCO). Two operators performed guided access cavities. A post-operative CBCT and IOS were acquired. The deviation coronally, apically, and angular deviation was measured with CBCT and IOS. Clinical accuracy was measured using an IOS acquired immediately after drilling the access cavity with the aid of a guide. Data analysis was performed using multiway Anova and corrected for simultaneous hypothesis testing according to Tukey. P ≤ 0.05 was considered statistically significant. Descriptive statistics on the clinical accuracy of guided endodontics were performed.

RESULTS

Thirty-eight cavities were assessed with a mean length of 13.8 mm. No statistical difference between operators and methods was found for all parameters (P > 0.05). Thirty-three patients were treated with guided endodontics and measured using an IOS. Results show an average coronal, apical, and angular deviation of 0.2 mm, 0.45 mm, and 1.91^° respectively. The average length of the access cavities was 12.5 mm.

CONCLUSIONS

An IOS can be used to measure the accuracy of guided endodontics. Clinical data showed high accuracy of guided endodontics with a mean apical deviation smaller than 0.5 mm and a mean angular deviation of less than 2^°.

CLINICAL SIGNIFICANCE

The use of an IOS does not involve additional radiation exposure. A safety margin of at least 1 mm around the planned trajectory should be respected when planning the case to minimize the possibility of root perforation.

In vitro study on the accuracy of sleeveless guided endodontics and treatment of a complex upper lateral incisor

PURPOSE

The present study aims to assess the accuracy of sleeveless guided endodontics for root canal treatment of severe pulp canal obliteration (PCO) in 3D printed jaws. Additionally, the treatment of a complex lateral incisor is presented to illustrate the use of sleeveless guides in a clinical situation.

METHODS

Two cone-beam computed tomography (CBCT) volumes of an upper and lower jaw were selected to design 3D printed models with PCO. Virtual planning of the access cavities was performed from right to left second premolar. Then, the models were mounted into a phantom head to simulate an actual patient. Two operators with different levels of experience in endodontics performed guided access cavities. The handpiece was guided by guiding rails placed against each other on the sides of the tooth. A post-operative CBCT scan was taken for analysis.

RESULTS

Eighty-eight guided access cavities (44 per operator) were drilled on eight 3D printed models. The mean length of the access cavities was 15.3 mm, with a mean coronal and apical deviation of 0.5 mm and 0.7 mm respectively. The mean angular deviation was 1.5^°. No statistically significant difference was found between operators for the three measured parameters.

CONCLUSIONS

This study demonstrates, within its limitations, that sleveless guides represent an accurate method for guided endodontic treatment. No statistically significant difference between operators was found when using the guide.

CLINICAL SIGNIFICANCE

This method offers a valuable alternative to conventional endodontic guides with similar accuracy results.

Dynamic navigation: a laboratory study on the accuracy and potential use of guided root canal treatment

AIM

To evaluate 3D accuracy and outcome of a dynamic navigation method for guided root canal treatment of severe pulp canal obliteration (PCO) in 3D printed jaws.

METHODOLOGY

Three operators with different levels of experience in Endodontics performed navigated access cavities, using the Navident system (ClaroNav), in two sets (maxillary and mandibular) of 3D-printed jaw models with teeth presenting severe PCO. Models were mounted on a phantom to mimic a real clinical situation. After treatment, a postoperative high resolution Cone-Beam Computer Tomography (CBCT) scan (NewTom) was taken for each model and registered to the preoperative model. All access cavities were then segmented using 3-Matic Medical software 15.0 (Materialise). Length and volume of each access cavity were measured, and a comparison was done by measuring the distance deviation in mm at the coronal entry point, apical point, vertical deviation, total deviation and angular deviation of the access cavity in comparison with the virtual planning. Additionally, all access cavities were scouted with a size 10 K-file and inspected on the CBCT to confirm that the canal was located. Descriptive statistics for each parameter were performed. Normality of the data was assessed; data were transformed if needed to make it normally distributed. One-way analysis of variance (anova) was applied to assess differences between parameters for tooth type, jaw, and operators and corrected for simultaneous hypothesis testing according to Tukey. Significance level was set at .05.

RESULTS

After training with the system (28 cavities per operator), a total of 132 teeth and 168 access cavities (56 per operator) were prepared. All operators located a total of 156 canals, obtaining an overall success of 93% without a difference between operator experience (p > .05). The mean deviation at the apical point was 0.63 mm (SD 0.35) and was significantly lower in anterior teeth in comparison with molars (p < .05). The mean angular deviation from the planning was 2.81° (SD 1.53).

CONCLUSION

Dynamic navigation was an accurate approach for root canal treatment in teeth with severely calcified canals. However, the technique has a learning curve and requires extensive training prior to its use clinically.