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After performing the laboratory/clinical exercises in this chapter, the student will be able to do the following:
1. Explain the rationale for composite finishing and polishing.
2. Recall the benefits of properly finished and polished composite restorations.
3. List two indications for finishing and polishing composite restorations.
4. Discuss the detrimental effects of poor composite placement and finishing.
5. Assess a composite restoration to determine whether it needs replacement or refinishing and polishing.
6. Differentiate between the procedures of composite finishing and polishing.
7. Evaluate a well-finished and polished composite restoration according to the criteria provided in this chapter.
The use of composite resin as an esthetic restorative material continues to expand. Once relegated to primarily anterior regions of the dentition where esthetics is a chief concern, composites are now being used to restore the entire dentition in a variety of situations. With this in mind, it is imperative that the dental hygienist be aware of the proper maintenance of composite materials to ensure periodontal health and prevent dental disease.
I. Purpose of Finishing and Polishing
The primary purpose of finishing and polishing composite restorations is to create a restoration that is smooth, uniform, and easily cleaned by the patient. This, in turn, can increase the longevity of the restoration, decrease the incidence of recurrent caries, and promote the health of surrounding tissues. Occasionally, patients will need to have their composite restorations polished and less often refinished.
A. Advantages of Finishing and Polishing
The following conditions result from proper finishing and polishing:
- Smooth, undetectable margins
- Plaque-resistant surface
- Healthier gingival tissues
- Increased longevity
- Enhanced esthetics
- Proper contours
B. Methods by Which These Benefits Are Achieved
These benefits are achieved by properly smoothing the cavosurface margins, reconstructing functional anatomy, and creating a surface that is smooth and free of voids. A smooth surface is necessary to simulate the high gloss of enamel.
II. Evaluation of Composite Restorations
Unlike amalgam restorations, composites can be completely finished and polished immediately after they are placed. Improper placement, incomplete finishing and polishing, or normal wear and tear increases the risk of recurrent caries, plaque retention, periodontal disease, and restoration failure. Composite restorations are evaluated as part of the dental examination. Some restorations may need to be finished and polished. In other instances, the restoration will need to be repaired or replaced.
A. Indications for Finishing and Polishing
1. Overextension or flash
2. Premature occlusal contact
4. Limited stain
5. Limited recontouring of anatomy
6. Small chips or defects
B. Indications for Repair or Replacement
1. Gross overextension or overhang
2. Open margin
4. Extensive stain
5. Recurrent caries
6. Open proximal contact
7. Larger defects
III. Finishing and Polishing Considerations
Similar to amalgam finishing and polishing discussed in Chapter 26, the process of finishing and polishing composite restorations can be considered two different procedures or two steps of a single procedure. During the finishing procedure, contours are corrected while margins and irregularities are smoothed. The polishing procedure should produce a smooth lustrous finish.
A variety of products are available ranging from burs, finishing strips, finishing disks, points, cups, pastes, and brushes, as pictured in Figure 36.1. Many manufacturers even market their own polishing systems. Some of the most common products are discussed in this chapter. The theory and process of finishing and polishing composites is consistent with that of other materials; a progression from coarse to finer abrasives is described in Chapter 16, Polishing Materials and Abrasion.
FIGURE 36.1. Abrasive disks, points, a cup, and burs used to finish and polish composite restorations.
Heat generation during finishing and polishing must be controlled. The thermal conductivity of composite is not as high as that of amalgam, but the risk of pulpal irritation or injury from increased temperatures must be considered. The use of a slow-speed handpiece, water as a coolant, and intermittent strokes is recommended to avoid heat buildup and transmission.
Finally, care must be taken not to damage adjacent teeth or soft tissues. Isolate the tooth or teeth with cotton rolls, dry angles, or a rubber dam to prevent iatrogenic injury to surrounding tissues.
IV. Procedure for Composite Finishing and Polishing
A. Evaluate Restoration
Because dental composites are tooth colored and often difficult to see, it is useful to thoroughly dry the restored tooth with a light stream of air from the air–water syringe. With the restoration dry, visually inspect the contours to detect proper anatomical form, chips, voids, stains, or defects. Occlusal contacts can be evaluated using articulating paper. Use an explorer to gently examine all of the margins of the restoration. Proximal surfaces can also be evaluated with an explorer. Proper contacts and gingival margins can be confirmed with dental floss.
B. Discuss Procedure with Patient
Explain the rationale of composite finishing and polishing and review the steps of the procedure with the patient. Inform the patient of sensations he or she may experience during the process, especially those of finishing burs with a low-speed handpiece.
C. Gather Necessary Equipment
Select instruments based on the restoration and the clinician’s preference. A list of equipment is included as Table 36.1.
TABLE 36.1. Armamentarium for Finishing and Polishing Composite Restorations
Tips for the Clinician
- Effective lighting and dried surfaces allow for improved evaluation of surface irregularities.
- The sequence of steps is crucial. Do not proceed to the next step until the previous step has been completed.
- Iatrogenic injury may occur to adjacent teeth or gingiva if the operator is not cautious.
- Heat can be generated rapidly on the tooth during composite finishing and polishing.
- Aerosols are created frequently when polishing with disks.
- An exposed metal shank or center of a disk will scratch and discolor the composite surface. Use care in positioning the disk.