Modified Crown-Down Filing Technique

Initially, hand files should be used to access the root canal, create a glide path, and determine working length. Hand files should then enlarge the canal at working length to at least a 15/.02 to 20/.02 file size. The size will depend on the actual tooth that is being treated. After this step, rotary-file instrumentation should be initiated. It has been documented in scientific literature that rotary nickel-titanium (NiTi) files can prepare a canal faster than hand files.³¹

Although there are many different file techniques for conventional endodontic treatment, the modified crown-down technique is a consistent and efficient method of treatment.³² The technique involves opening the coronal two-thirds of the canal with rotary files. Several types of “orifice opener” rotary files are on the market. Next, the rotary files should be worked from larger- to smaller-size files working your way to the final working length. It is recommended to use a 0.04 taper rotary-file system when preparing the root canal for obturation. The last rotary-file size that can be taken to working length in a canal is considered the master apical file and in most basic cases should be no smaller than a size 30 or 25.

A clinician must use a rubber dam for tooth isolation when performing endodontic treatment as this is considered standard of care.