Comparative evaluation of dentinal crack formation after root canal preparation using Pro Taper universal, Pro Taper Next and Pro Taper Gold

Success of endodontic treatment depends on strict adherence to cleaning and shaping procedures.1 Root canal preparation technique involves complete disinfection and debridement of microorganisms from the canal, preparing and shaping the canal for placement of filling material but some amount of sound dentin also gets removed during the cleaning and shaping procedures.2 Excessive removal of sound dentin may weaken the tooth structure making it highly susceptible for perforation and dentinal crack formation under some instances. Procedures like use of high concentration of sodium hypochlorite,3 placement of intracanal post4 and some obturation techniques5 may aid in excess removal of dentin and ultimately leading to crack formation. However, it is the use of rotary instruments that have been identified as major cause for occurrence of dentinal cracks along root canal walls.6 The introduction of Niti rotary file systems made the cleaning and shaping procedures faster, efficient because of their super elasticity7 and high cutting efficiency8 . One of the major drawbacks of niti rotary systems is that it caused cracks along the root canal walls during preparation. The main reason for formation of dentinal cracks is when tensile strength of root canal wall exceeds tensile strength of dentin 9.10,11. These cracks can be extended as vertical root fracture (VRF) under constant functional load12 Even though there are several studies that evaluate the incidence of dentinal crack formation after root canal preparation with different Niti systems 13,14,15,16,17,18,19 none of the studies evaluated the incidence dentinal crack formation with the all the three Protaper systems. (ProTaper Universal (PTU), ProTaper Next (PTN), ProTaper Gold (PTG)). The Null hypothesis is there will be no difference in dentinal crack formation among all the three Protaper systems tested.