Absolute isolation in the anterior segment


The execution of the rubber dam anterior follows exactly the same principles already demonstrated for the isolation of the posterior teeth. However, because of the greater aesthetic importance of the anterior teeth, there is an important operatory difference: often, it is of more interest that the preparation procedures are conducted under relative isolation - to minimize dehydration of the teeth structure and the accompanying color change - while the absolute isolation is performed only at the moment when the preparation is completed. The main advantage of this approach is to allow for the execution of a try-in restoration, with the application of the selected composites directly on the tooth structure.
Another important difference is that, in most cases, isolation of the anterior teeth with a rubber dam can be performed without the use of clamps, except for those situations where there is a need to promote retraction of the gingival tissues - check an example in this post.

The step by step sequence shown here illustrates the key steps for the implementation of absolute isolation for the anterior segment. Initially, the pressure of regular contacts and proximal surfaces should be assessed. If contacts are found to be overly tight or accompanied by surface irregularities, factors that greatly hinder the passage of the rubber sheet, one should make an adjustment with interproximal abrasive strips.



Then, the rubber sheet is adapted to the young frame and the positions planned for the punches are marker with a felt tip pen. Then, the sheet is perforated, however, in this case the isolation is being performed without the use of clamps so that the punches of both ends are not made with the larger diameter of the punch.
The frame/sheet assembly is then positioned over the teeth and with the help of dental floss, the interdental rubber festoons are passed through the points of contact and the dam is invaginated in the cervical region in order to improve sealing.


The rubber dam is completed with the installation of loops at both ends. In situations like that presented in this sequence ( anterior isolation from canine to canine ), the loops made with dental floss are a very practical way to ensure the stabilization of the rubber dam without the use of clamps. The loops can be made extraorally with false nodes, in order to facilitate their adaptation to the tooth. After the insertion, a blunt-tipped spatula is used on the opposite face of the node in order to press the floss to the cervical, while the knot is tightened.



After completion of the insertion, the dental floss can be cut close to the knot in order to not unnecessarily obstruct the operatory field. It is also possible to stabilize the position of the sheet with wooden wedges or with special rubber cords, specially designed for this purpose. Our preference, however, is using very small sections of the rubber dam itself cut in a region that does not interfere with the quality of isolation (eg, on the corner of the sheet). After cutting, these small sections are handled gently between two fingers, taking the form of small rolls which, when stretched, reduce in thickness, allowing for easy insertion. The choice for one or another alternative depends on the performance of the professional, since they all perform well, provided that they are probably used.

It should be clear, however, the use of clamps may be required in certain situations, so that each case should be evaluated individually. In this situation, for example, if there was diastema between the canine and premolars, none of the alternatives presented here would be able to adequately stabilize the rubber sheet.