Title: The effect of different types of access cavities on the adaptation of the root filling

The success of endodontic treatments is determined by the use of appropriate instrumentation, the ideal configuration of the access cavity, the exploration and preparation of the root canal, the thorough disinfection of the canal, and the construction of an airtight and hermetic root canal obturation. Traditional endodontic access cavity (TEC) modeling involves creating a cavity on the occlusal surface of the tooth, followed by corresponding opening of the pulp chamber of the tooth to provide access to the canal openings. In the case of the truss endodontic access cavity (TREC) method, part of the roof of the pulp chamber is retained, providing separate access to each root canal.

The purpose of this research is to compare the adaptation of the root canal obturation to the root canal wall in the case of the two access cavity modeling methods (TEC and TREC). In our study, 6-6 molar teeth were prepared using TEC and TREC access cavity modeling methods, followed by root obturation and crown obturation. Using a slicing machine, 3 equal sections were made from the roots of the teeth: the first section was made at the enamel-cementum interface, the second section in the middle third of the root, and the third section in the apical third. Photographs of the sections were taken using a macro lens. Each of the three incisions allowed measurement of the area of ​​root obturation and resulting gaps on 2 to 2 surfaces. The surface area of ​​root fillings and voids were measured using “Image-Pro Insight” software. The presence of gutta-percha was examined in sections taken in the apical third. The obtained results were subjected to statistical analysis using Mann-Whitney and Chi-square tests. No significant differences were observed between the coronal, middle and apical thirds in terms of root filling area. For the two access cavity modeling methods (TEC and TREC), the presence or absence of gaps – between the root filling and the root canal wall – showed no statistically significant differences in the coronal and middle thirds. However, significantly fewer lacunae were observed in the apical third in the TEC-trained group than in the TREC-trained group (p=0.01). There was no significant difference between the two groups in the presence of gutta-percha in the apical third (p=0.43). Our study suggests that, although there is no difference in the adaptation of root filling margins in the coronal and middle thirds for the two access cavity modeling methods, the TEC method is more accurate in the apical third. Endodontic treatment is more successful, especially for a novice dentist, when it uses traditional access cavity shaping to open the root canals.