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After performing the laboratory/clinical exercises in this chapter, the student will be able to do the following:
1. List the indications and contraindications for placing the rubber dam.
2. Describe the purpose of the rubber dam armamentarium (rubber dam, rubber dam clamp, punch, etc.).
3. Summarize the steps for placement and removal of the rubber dam.
Basic, step-by-step instructions for application and removal of the rubber dam are discussed in this chapter. In most cases, one of two placement techniques is routinely used: the one-step method, in which the dam and clamp are placed simultaneously or the two-step method, in which the clamp is placed on the anchor tooth and the dam material is then stretched over the clamp. In this chapter, the one-step method will be the technique of choice.
Clinical success of rubber dam isolation (exposure of selected teeth) is determined by the placement and retention methods of the clinician. Problems with rubber dam placement are often the result of torn rubber dam material, improper hole size and placement, or inadequate tautness of frame placement.
The rubber dam is usually placed after local anesthesia has been administered and while waiting for that anesthetic to take effect. Proper rubber dam placement can be achieved by a clinician in 3 to 5 minutes or, with a team approach, within 2 minutes.
I. Purpose and Indications
Proper isolation during technique-sensitive dental procedures is important but is also sometimes difficult to achieve. The purpose of rubber dam placement is to improve the overall quality of dental treatment. Indications for rubber dam placement are moisture control, visibility, patient protection, and patient treatment.
Rubber dam placement allows the clinician to achieve a dry field by isolating the tooth (or teeth) indicated for treatment from oral fluids and other oral tissues (lips, cheeks, tongue, and gingiva). This protects the patient from swallowing or aspirating (drawing into the lungs) debris and dental objects that are used during the procedure. It also protects the tissues from irritating materials used for the procedure such as acids for etching enamel.
Rubber dam placement is contraindicated for patients who are claustrophobic, suffer from severe asthma, or have trouble breathing through their nose. Other contraindications include patients with teeth that are not fully erupted as the clamp may not be stable and patients who cannot tolerate the clamp without anesthesia.
The success of rubber dam placement is dependent on the technique and skill of the clinician. The items needed for rubber dam placement are listed in Table 24.1.
TABLE 24.1. Armamentarium for Placing the Rubber Dam
A. Choosing the Rubber Dam Material
Selection of the rubber dam material is based on the clinician’s preferences regarding size, color, and thickness. Traditional dam material was latex rubber. Nonlatex rubber dams are necessary for those patients or operators with a latex hypersensitivity. Nonlatex dams are becoming popular. The most common size is the precut, 6- × 6-inch square, which is used for isolation of posterior teeth in the permanent dentition. Another common size is the precut, 5- × 5-inch square, which is used for primary dentition or anterior applications. A continuous roll of rubber dam material is available as well, and the choice of colors ranges from pastels to browns and greens. The color is used to contrast the tooth, making the treatment field more visible.
The rubber dam is also available in thicknesses (gauges) of thin, medium, and heavy. The medium rubber dam is widely used because of its ease of handling and resistance to tearing. The armamentarium, less the rubber dam stamp and ink pad, is shown in Figure 24.1.
FIGURE 24.1. The basic rubber dam armamentarium.
B. Preparing the Rubber Dam Material
1. Stamp the Material
The rubber dam stamp has markings for the average permanent and primary dentitions. The use of the stamp allows several sheets of dam material to be marked in advance. A rubber dam stamp and stamped dam are shown in Figure 24.2.
FIGURE 24.2. A rubber dam stamp and a stamped dam.
2. Punch the Holes
Next, holes are punched into the rubber dam to correspond to the teeth that are to be isolated. The rubber dam punch usually consists of a rotating punch plate that allows holes of five or six different sizes and a metal point (punch) that creates the holes. The larger holes are used for posterior teeth, the smaller holes for premolars and canines, and the smallest holes for incisors. Correct hole size plays a critical role in successful tooth isolation.
3. Prepare the Clamp (Retainer)
The clamp is prepared by threading floss through the facial hole and then tying a knot. This prevents the clamp from being aspirated should it spring free and allows for quick retrieval. The clamp is used as an anchor for the dam material and to retract the gingiva. Both winged clamps (clamps with extra projections) and wingless clamps (clamps without projections) are available, as are different shapes and sizes to fit the primary and permanent teeth. These are illustrated in Figure 24.3. The extra projections of winged clamps allow the dam and the clamp to be applied simultaneously. These are shown in Figure 24.4. When wingless clamps are used, they are applied first to the tooth, and the rubber dam is then stretched over the clamp and the tooth.
FIGURE 24.3. An assortment of rubber dam clamps: winged clamps (right side), wingless clamps (left side), and “butterfly-shaped” clamps (middle) used to isolate anterior teeth and the buccal of some posterior teeth (see Fig. 24.8).