title: Evaluation of conventional, protaper hand and protaper rotary instrumentation system for apical extrusion of debris, irrigants and bacteria- Anin vitrorandomized trial.
abstract: BACKGROUND
  Endodontic instrumentation carries the risk of over extrusion of debris and bacteria. The technique used and the type of instrumentation influences this risk.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate and compare the K-file, ProTaper hand and ProTaper rotary instrumentation systems for the amount of apically extruded debris, irrigant solution and intracanal bacteria.
  
  
  METHODS
  Experimental single blinded randomized type of in vitro study with sample of 30 single rooted teeth. Endodontic access cavities were prepared and the root canals were filled with the suspension ofE. faecalis. Myers and Montogomery Model was used to collect apically extruded debris and irrigant. Canals were prepared using K files, Hand protapers and Protaper rotary files.
  
  
  METHODS
  Non Parametric test like Kruskal-Wallis and Mann-Whitney U test were applied to determine the significant differences among the group.
  
  
  RESULTS
  Tests revealed statistically significant difference between the amount of debris and number of bacteria extruded by the ProTaper hand and the K-files. No statistically significant difference was observed between the amounts of irrigant extruded by the ProTaper hand and the K-file system. Statistically significant differences were observed between the amounts of bacteria and irrigant extruded by the ProTaper rotary and the Protaper hand. No statistically significant difference was observed between the amounts of debris extruded by the ProTaper hand and the K-file system.
  
  
  CONCLUSIONS
  Amount of apical extrusion of irrigant solution, bacteria and debris are significantly greater with K File instruments and least with Protaper rotary instruments.Key words:Protaper, rotary, periapical extrusion.
authors.affiliation: Ex-Post Graduate Student, Paedodontics & Preventive Dentistry, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka State, India.
authors.forename: Pinky
authors.initials: P
authors.lastname: Kalra
authors.affiliation: Professor & Head, Paedodontics & Preventive Dentistry, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka State, India.
authors.forename: Arathi
authors.initials: A
authors.lastname: Rao
authors.affiliation: Associate Professor, Microbiology, Kasturba Medical College, Mangalore, Manipal University, Karnataka State, India.
authors.forename: Ethel
authors.initials: E
authors.lastname: Suman
authors.affiliation: Associate Professor, Public Health Dentistry, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka State, India.
authors.forename: Ramya
authors.initials: R
authors.lastname: Shenoy
authors.affiliation: Professor, Paedodontics & Preventive Dentistry, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka State, India.
authors.forename: Baranya-Shrikrishna
authors.initials: BS
authors.lastname: Suprabha