Separators: a review of uses and limitations

Orthodontic separators are routinely used to create space between teeth, usually molars and/or premolars, prior to the placement of orthodontic bands. Separators are also used to create space to facilitate interdental reduction. Orthodontic auxiliaries can also be used for a variety of other purposes, which will be described. Additional indications are:

Separators are simple orthodontic auxiliaries, which are cheap and easily available. They have many benefits, however, there are also risks associated with the use of separators, most commonly discomfort but also localized periodontal disease if the separator is retained subgingivally.

Various techniques have been described in Orthodontics to create space between teeth (Figure 1). These include elastomeric separators, brass wire, elastomeric thread,¹ latex elastics, and a variety of spring separators.

Prior to steel or elastomeric separators, a brass wire was placed tightly against the contact point for about one week (Figure 2). This was uncomfortable and could be traumatic to the gingivae.² Brass wire has been superseded by elastomeric materials and, less commonly, steel springs, which can also cause a level of discomfort. Elastomeric modules are very popular as they are easy to use, are low cost but are extremely effective. Although separators are usually prefabricated, steel springs may be constructed at the chairside.³ Steel separators are available in a number of preformed designs and shapes where different types have been described, such as Kesling and NEET springs. They are placed by manipulating one leg of the spring into the embrasure, after which pressure on the spring allows the second spring to be placed under the contact point. Although elastomeric separators have been shown to provide greater separation than spring separators (0.3 mm compared to 0.4 mm after 5 days),^4,5 both auxiliaries provide an adequate amount of separation for the placement of orthodontic bands. Elastomeric separators can be more difficult to insert than other materials. However, they are less likely to be lost, have a short span of force application and may be left in situ for a greater period of time, although ideally not exceeding two weeks.^5,6,7 Elastomeric separators are more cost-effective than other forms of separator, can vary in width (Figure 3), and are usually fabricated in bright or bold colours so that they may be easily identified and removed. However, clear separators are also available for anterior teeth if needed. Elastomeric separators are commonly circular, although other shapes, such as Dumbbell separators, are also available. Elastomeric separators are placed by stretching and slipping through the contact point, either by using two pieces of floss threaded through the centre, two mosquito clips or using separating pliers (Figure 4).