title: Evaluation of the root dentine cutting effectiveness of the HERO 642, HERO Apical and HERO Shaper rotary systems.
abstract: Different HERO rotary systems were evaluated by pre- and postoperative images of a cross-section of their mesiobuccal root thirds with a stereoscopic magnifier (45x). Fifty mesiobuccal canals of human mandibular first molars were divided into five groups: 1--HERO 642; 2--HERO 642 and HERO Apical; 3--HERO Shaper; 4--HERO Shaper and HERO Apical; 5--NitiFlex files. The perimeter of the canal was calculated using Image Tool software (UTHSCA). Final, post-instrumentation perimeters were compared by Kruskal-Wallis test (P = 0.05). The distribution of the values of the final canal perimeter for each instrumentation method was not statistically significant in any of the thirds (P = 0.174, cervical third; P = 0.874, middle third; and P = 0.631, apical third). An increase in canal perimeter was observed in all groups. In the cervical third the greatest increase was Group 5; in the middle third, Group 4, and in the apical third, Group 2.
authors.affiliation: Department of Prosthetics and Oral and Facial Surgery, MSc Course in Integrated Clinical Dentistry, Faculty of Dentistry, Federal University of Pernambuco, Recife, Brazil.
authors.forename: Andréa Cruz
authors.initials: AC
authors.lastname: Câmara
authors.forename: Carlos Menezes
authors.initials: CM
authors.lastname: Aguiar
authors.forename: Jose Antonio Poli
authors.initials: JA
authors.lastname: de Figueiredo
mesh_terms: D003722:Dental Alloys; D003762:Dental Instruments; D003799:Dental Stress Analysis; D003804:Dentin; D006801:Humans; D008963:Molar; D009532:Nickel; D018915:Root Canal Preparation / Q000295:instrumentation*; D014025:Titanium
chemical_list: D003722:Dental Alloys; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium