April 1, 2014
by Bob Margeas, DDS
Patient demand for aesthetic dentistry with minimally invasive procedures has resulted in the extensive utilization of freehand bonding of composite resin to anterior teeth.1 The development of composite resins with natural fluorescence and polishability allows the clinician to mimic the natural dentition. Composite resins allow for conservative treatment and long lasting restorations. In order to achieve a natural appearing composite restoration, the clinician must have a knowledge of the properties of composites, and which materials to use in each clinical situation. There are a variety of materials to choose from including, microfills, hybrids, microhybrids, and the newer nanotechnology materials. Today’s composite resins exhibit dramatically improved physical and optical properties, rendering them the ideal materials to facilitate restorations that are indistinguishable from the natural dentition.
Dental patients are more conscious of their appearances and have raised the importance of the smile within society as a whole; this impacts full mouth restorations as well as more conservative restorative procedures that include class IV restorations, diastema closures and veneers of the teeth.2,3
Direct resin restorations require skill and commitment from the clinician. It is a learned technique. Hands on courses provide some of the best learning opportunities when trying to perfect the technique. Prior to performing a restorative procedure, the clinician must achieve a heightened sense of observation to visualize the properties (ie. opacity, form, color, characterizations, surface texture) of the natural teeth.4-6 One of the advantages of a direct resin restoration over a porcelain restoration is that the clinician is able to maintain control and customize the materials throughout the procedure. With porcelain, any modification means a return to the laboratory for correction. When choosing the proper shade of composite for a direct composite restoration, the dentist must first understand hue, chroma, and value. Hue is commonly understood as the name of the color or the basic shade. Chroma can be defined as the intensity of color or the degree of hue saturation. The most important of the color dimension is value,7 which distinguishes light from dark colors. The value can be defined as the brightness of color.
While excellent aesthetics are possible with indirect restorations, there may be unnecessary tooth structure removed in order to achieve the desired results. This may affect the long-term success of the restoration, when dealing with younger patients. When possible, augmentation versus amputation allows for a more conservative treatment option.
The diastema presents itself to the dental office on a regular basis. It may be small or large. The papilla may be long and skinny, or blunted. The size will have an effect on what material will be chosen to achieve the desired results. When dealing with a larger space closure, orthodontics may be indicated to allow for a more aesthetic outcome.
When the teeth are in proper orthodontic alignment, no preparation of the tooth structure is necessary. If there is an alignment problem, minor tooth preparation will be necessary to achieve proper arch form. The following case report shows a restorative protocol when addressing the diastema.
A 30 year-old patient presented to the office with a small, 1mm diastema between the lateral and central incisor. It was his desire to have the space closed. The pre-op retracted view revealed excellent tissue health and an ideal color (Fig. 1).
The only treatment option given to the patient was to restore the teeth with composite resin. The patient only desired to have the diastema closed. Ideal alignment meant that no tooth structure would be removed prior to restoring the case. Although a rubber dam could be used for isolation, in this case, cotton roll isolation was used. The teeth were pumiced first prior to etching. Air abrasion could also have been used to clean the surface prior to etching.
The lateral incisor was acid etched for 20 seconds (Fig. 2), rinsed and air dried. It is very important to not get etch on the adjacent teeth as this will cause the first layer of composite placement to bond permanently to the distal of the central. The enamel exhibited an excellent etch pattern. The adhesive was applied in a thin layer, and lightly air- thinned. It is important not to allow the adhesive to pool around the gum tissue. If this occurs, the composite will not be able to be placed subgingivally.
A single shade of composite was chosen that will provide a chameleon effect (Fig. 3). The composite is placed freehand using a long bladed titanium instrument and sculpted beneath the free gingival margin. The facial wall is the only thing that needs to be addressed in this increment. It is sculpted and shaped to the ideal contours. The lingual will be back filled against the cured facial wall in the second increment. A brush was used to thin the material out as much as possible, trying to avoid a thick margin. It is important that you over etch the surface, because you do not know exactly where the composite will end. You blend the material until the margin disappears. This increment is then light cured for 40 seconds.
Figure 4 shows the final cured composite on the lingual. You will notice a void on the lingual. This will be back filled with the second increment. An instrument is then placed at the cervical area and the teeth are torqued apart (Fig. 5). The material will not bond because the area was not etched. It is important to let the patient know they will hear a pop when the teeth are separated.
This freehand technique will allow for a perfect contact without using wedges or matrices. A matrix strip is then placed interproximally under the free gingival margin taking care not to cause any bleeding. Figures 6 and 7 show the matrix in place. A small increment of composite is placed on a thin titanium instrument (Fig. 8) and placed on the lingual against the cured facial wall. Here is where a clear matrix is used as an instrument to pull the material
against the cured facial wall. The matrix band is now slowly pulled through to the facial, dragging the material against the cured wall and sealing the margin. Figures 9, 10 and 11 demonstrate the pull through technique. A thin titanium instrument is then used to tuck the margin under the gumline prior to final finishing. The tooth is now finished with carbide burs, disks, diamond strips, and finishing strips to allow a smooth interproximal surface. A number 12 scalpal can be used if there is an overhang present. Figures 12 and 13 show the final restoration on the day of placement. There is no need to use wedges or damage the tissue if it is healthy.
FIGURE 9.FIGURE 10.
CONCLUSION:Composite resin is an ideal material when restoring diastema closures. It is highly polishable, long lasting, and mimics natural tooth structure. It is a conservative alternative to an indirect restoration. Freehand bonding allows the dentist to be an artist and gives total control to the operator.OH
Dr. Margeas is a Board Certified by the American Board of Operative Dentistry and is an adjunct professor in the dept. of operative dentistry at the U. of Iowa College of Dentistry. He is on numerous editorial boards and lectures and performs hands-on courses internationally. He maintains a private practice in Des Moines, Iowa.
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REFERENCES:1. Dietschi D. Free-hand composite resin restorations: A key to anterior aesthetics. Pract Periodont Aesthet Dent 1995;7(7):15-25.
2. Fahl N Jr. Optimizing the esthetics of Class IV restorations with composite resins. J Canad Dent Assoc 1997;63(2):108-115.
3. de Araujo EM, Baratieri LN, Monteiro S, et al. Direct adhesive restoration of anterior teeth: Part 1. Fundamentals of excellence. Pract Proced Aesthet Dent 2003; 15(3):233-240.
4. Winter R. Visualizing the natural dentition. J Esthet Dent 1993;5(3):102-117.
5. Terry DA, Geller W, Tric O. Anatomical form defines color: Function, form, and aesthetics. Pract Proced Aesthet Dent 2002;14(1):59-67.
6. Ten Bosch JJ, Coops JC. Tooth color and reflectance as related to light scattering and enamel hardness. J Dent Res 1995;74(1):59-67.
7. Sproull RC. Color matching in dentistry. The three-dimensional nature of color. J Prosthet Dent 1973; 29(4):416-424.
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