Safe-Core™ Parobolic Cross-Section

It has been shown that the Parabolic Cross-Section is the best design to perform deep drilling and reaming as performed during root canal treatment. The Parabolic Cross-Section combines the attributes of being a highly efficient and flexible cutting instrument with being extremely safe and resistant to fracture. Here are the reasons:

Safe-Core™:
The Safe-Core™ feature results in an instrument that is very resistant to fracture

Symmetric Shape:
Prevents excessive stress and strain on the file to make it very resistant to fracture

No Land:
A land makes a very inefficient cutting instrument, causing tremendous drag and friction, which can result in heat build-up in the file. This can result in fractured instruments. Never use an instrument with a land.

No Excessive Clearance Angle:
A triangle-shaped file has a clearance angle over 30 degrees, which is designed to cause a great deal of side cutting and canal transportation. Never use an instrument with a triangular shape.

Neutral Rake Angle:
A neutral rake angle is a very efficient cutting angle, the best for root canals and deep-hole reaming. A positive rake angle will gouge and grab the canal walls. This gouging and grabbing puts unnecessary torque on the canal and forms “hot spots” on the file, which can result in fracture. A negative rake angle will drag and burnish the walls of the canal, which can result in heat build-up in the file and fractured instruments.

No Reverse Cutting:
The parabolic design does not cut or engage in the reverse direction (CCW.) An electric torque control motor will turn in the reverse direction when the torque limit is reached. A file with a land or triangular cross-section will engage dentin in the reverse direction and place undue stress on the file. This stress can lead to decreased file life and fracture.

Overview:
The Parabolic Cross-Section, featuring the combination of the Safe-Core™, symmetrical design, no land, conservative clearance angle, neutral rake angle, and no reverse cutting, results in the instrument that is perfectly designed for root canals and deep-hole drilling and reaming.

For deep-hole drilling and reaming application in other fields, no professionals use, nor do manufacturers even make, a U-Shape, or Triangular shape instrument. Instead, thousands of times a day, they use the Parabolic Cross-Section—the standard for this application because it is the best design.