Clinical Update

The clinical update online is a free member service providing up to 11 FREE CPD hours per year.

Each month, the clinical update is published online and in the Victorian Dentist. There are 11 clinical updates per year, corresponding with the distribution of the Victorian Dentist from February to December. This service is available to ADAVB and ADATas members only. Members can log in to view and answer the clinical update questions. If you answer at least eight out of 10 questions correctly, you will receive one hour of scientific CPD.

Please note: Each new clinical update will be available from the first business day of each month.

Comparison of antibacterial effectiveness of three rotary file systems with different geometry in infected root canals before and after instrumentation – a double-blinded randomized controlled clinical trial

Siddique R, Nivedhitha M.S, Ranjan M, Jacob B, Solete P. BDJ Open (2020)6:8;

Compiled by Dr Aaron Martin and
Dr Sarah Chin


Effective chemomechanical debridement is important in reducing the bacterial load residing in the complex root canal systems. Machine-driven devices have been designed to improve the speed of root canal preparation, and these can range from automated, sonic, ultrasonic, laser systems and non-instrumental root canal preparation techniques.

The ProTaper Next uses M-Wire technology and has five files (X1-X5) with tapers of 0.04-0.07mm. It has an off-centred rectangular cross section design that gives it improved strength and asymmetrical rotary motion, which helps with canal shaping efficiency and cyclic fatigue resistance. It also helps the file to make a two-point contact with each canal. The ProTaper Gold has a triangular cross section and progressive taper, which improves cutting action while decreasing rotational friction between the blade of the file and dentine. There is less transportation and it maintains more dentine than the ProTaper Universal (PTU). Specialised heat treatment results in a different phase transformation, higher flexibility and higher cyclic resistance. XP-endo Shaper uses MaxWire technology and is a snake-shaped instrument that has a triangular booster tip cross-sectional design with six sharp cutting edges at the tip. The tip increased from an ISO 15 to and ISO diameter 30. It has an eccentric rotary motion as it has a semi-circular shape. It follows the shape of the canals. Studies have shown that the XP-endo Shaper induces minimal stress on dentinal walls and is effective in reducing microbial counts in oval shaped canals.

There is a lack of studies proving the effectiveness of three-dimensional rotary systems over traditional files. There is also the need for studies of three-dimensional rotary systems in clinical trials. The aim of this clinical trial was to compare the microbial load reduction of three rotary endodontic file systems in infected root canals of teeth with asymptomatic apical periodontitis. The null hypothesis was that there was no statistically significant difference in microbial load reduction between three rotary systems.

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