title: Evaluation of two different root-end cavity preparation techniques: A scanning electron microscope study.
abstract: OBJECTIVE
  In this study, we aimed to evaluate and compare the dentinal walls of root-end cavities for the presence of cracks after cavity preparation using US retrotips and Er: YAG laser.
  
  
  METHODS
  Fifty single-rooted teeth were prepared by Protaper NiTi rotary system and obturated by lateral condensation. Three milimeters of root-end was resected. Twenty teeth were prepared with US retrotip (Group 1), 20 teeth with Er: YAG laser (Group 2), and 10 teeth without retropreparation (control group). The root-end surfaces were examined under a scanning electron microscope (SEM). Then the cracks of the resected root surfaces were evaluated on microphotographs.
  
  
  RESULTS
  No statistically significant difference was detected between US Group and Laser Group for complete, incomplete, intradentinal, and total number of cracks (P = 0.47, P = 0.80, P = 0.69, P = 0.869, respectively).
  
  
  CONCLUSIONS
  Statistical analysis revealed no significant effect of retropreparation technique on the development of apical cracks (P > 0.05).
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Kocaeli University, Kocaeli, Turkiye.
authors.forename: Seda
authors.initials: S
authors.lastname: Aydemir
authors.affiliation: Department of Restrorative Dentistry, Faculty of Dentistry, Marmara University, Istanbul, Turkiye.
authors.forename: Hale
authors.initials: H
authors.lastname: Cimilli
authors.affiliation: Department of Metallurgical and Materials Engineering, Yildiz Technical University, Istanbul, Turkiye.
authors.forename: Afife Binnaz Hazar
authors.initials: ABH
authors.lastname: Yoruç
authors.affiliation: Department of Restrorative Dentistry, Faculty of Dentistry, Marmara University, Istanbul, Turkiye.
authors.forename: Nevin
authors.initials: N
authors.lastname: Kartal
keywords: Er: YAG laser; retropreparation; root-end cavity; ultrasonic retrotips