While retraction cords can be used for crown preps, it’s best to do so rarely. The reason for this is because you want to ensure your margins are either supragingival or equigingival. When retraction is necessary, it is wiser for dentists to use a diode laser. Another option is an H&H impression (which will drive the impression material in a sub gingival manner without retraction.
When Should Retraction Cords Be Used?
One circumstance where dentists will definitely want to utilize retraction cords is for cervical composites. The reason for this is because should you be using a headlight with magnification, you will have an outstanding view of crevicular fluid flow, so much so that it can be astounding. At this point many dentists use an air syringe to blow it away, only to have it well up almost immediately. This increases the risk of contamination for the composite which is bonded near gingival margins, which in turn can result in failure.
However, when a retraction cord is correctly placed, it will act as a highly effective dam against heavy crevicular flow. The second reason retraction cords should be used is because they will provide excellent visualization of margins which are restorative when making preparations, as well as during composite placement and finishing. It decreases the finishing that is necessary for gingival margins, and when a dentist has good visualization of the margin, they can readily adapt their composite material with the minimum flash. In a nutshell, it makes polishing and finishing a much easier process, both for the dentist and their patient.
Which Retraction Cord Is Best?
There are many types of retraction cords available, but the best is Ultrapak. It consists of thousands of miniature loops comprised of one hundred percent cotton which are knitted in such a way where they form chains which are long and interlocking. The knitting design used by Ultrapak retraction cords is distinct and will exert an outward force which is continuous and gentle after they have been placed. Their sizes range from thin to thick, and their caps incorporate a built-in cutter which is exceptionally handy.
Another piece of equipment that should be used in conjunction with Ultrapak is the Ultrapak Packers. These are specialized devices which can be used for cord packing, and they come with tips that are thin, round and serrated. They are also double ended, and each side will have a 45 degree offset. The purpose of the serration is so that they can attach to the Ultrapak cord making it much easier to accurately position it on the sulcus. When used together, they transform what in the past was a time consuming and tedious task into one that is much faster and straightforward. Retraction cords are highly effective in treating patients who have numerous cervical abfractions which capture food and are very sensitive.