Influence of size and taper of basic root canal preparation on root canal cleanliness: a scanning electron microscopy study

• Published in: International endodontic journal 2019-03, Vol.52 (3), p.343-351
• Main Authors: Plotino, G., Özyürek, T., Grande, N. M., Gündoğar, M.
• Format: Article
• Language: English
• Subjects: Data processing; debris; Dental roots; Dentistry; EDDY; Endodontics; Lavage; Mandible; mandibular molar; Molars; root canal preparation; Root canals; Scanning electron microscopy; smear layer; Sodium; Sodium hypochlorite; Teeth
• ISSN: 0143-2885; 1365-2591
• DOI: 10.1111/iej.13002

Aim To investigate whether a minimally invasive basic root canal preparation technique has an influence on root canal cleanliness in extracted mandibular molar teeth. Methodology A total of 80 root canals (40 mesio‐buccal and 40 mesio‐lingual) from 40 mandibular molars were included. The teeth were divided equally into four different experimental groups depending on the subsequently root canal preparation technique: Group 1: a basic preparation was performed up to size 20, .04 taper; Group 2: a basic preparation was performed up to size 2, .06 taper; Group 3: a basic preparation was performed up to size 25, .04 taper; and Group 4: a basic preparation was performed up to size 25, .06 taper. After the use of each instrument, each root canal was irrigated with 2.5 mL of 6% sodium hypochlorite for 30 s. Then, 1 mL NaOCl was activated for 20 s using an EDDY sonic tip. Final irrigation was performed using a total of 5 mL of 17% EDTA solution. The roots were then split longitudinally and all root canal thirds were observed through scanning electron microscopy (SEM) to evaluate the presence of superficial debris and smear layer using a scoring system. Data were statistically analysed using the Kruskal–Wallis and Bonferroni tests with a level of significance set at P  0.05), whilst in the apical third significantly less debris and smear layer was found in specimens from groups 3 and 4 than for groups 1 and 2 (P