Today’s Composite Resins Part 2: Versatile, Aesthetic, and Conservative

Composite resin formulations have un­dergone significant evolution in re­cent years and clinicians are challen­ged to understand the technical changes as well as the scope of application of these new naturally shaded composite systems (NSCS). Creation of natural, lifelike restorations and cosmetic enhancements is a learned skill that does not require innate artistic talent. The use of the new NSCS, described in part 1 (July 2009, Dentistry Today) is intuitive, in that the dentist simply replaces the missing tooth structure (ie, dentin, enamel, and transenamel) with the corresponding opacity of composite. In addition, dentists need to learn to see various subtle characterizations that exist in teeth so these can be included. Although a description of how to develop a heightened sense of observation is beyond the scope of this article, this skill is easily learned.
The different cases presented below will help the clinician understand the layering rationale needed to create lifelike aesthetic restorations and cosmetic enhancements using today’s advanced composite resins.

Figure 1. This 16-year-old was dissatisfied with her previous dentist’s treatment of the white spot lesions on her central incisors.

CASE 1
History and Diagnosis
A 16-year-old female reported with a chief complaint of being dissatisfied with previous dental treatment of her maxillary central incisors. Her dental history revealed that she had large white spot lesions in the incisal one third of each of these teeth. She stated that these appeared following orthodontic treatment. Several months earlier another dentist had placed composite resin restorations in both her central incisors and she was dissatisfied with the result (Figure 1). The clinical examination showed these quite visible restorations to be lacking in natural appearance, and to have marginal discoloration. Although the shade was close to being correct, they were not lifelike in appearance. This was a result of using only a single opacity of composite resin in the restorative technique. The discoloration was likely due to inadequate enamel adhesion at the margins.

Clinical Technique
It is important to take the shade quickly at the beginning of treatment to avoid the effects of enamel dehydration and the concurrent brightening effect on value. Using the middle-third of the lateral incisors as a reference, the shade was determined to be A1. Mild dispersed white areas, scattered irregularly in all the upper incisors, were also noted.

Figure 2. An egg-shaped diamond was used to create saucer-shaped preparations, approximately 0.7 mm deep in the center.	Figure 3. The preparations were feathered and scalloped an additional 1 to 1.5 mm beyond the white spots.
Figure 4. Because of its opacity, Dentin shade A1 (Empress Direct [Ivoclar Vivadent]) blocked the visibility of the white spot.	Figure 5. Empress Direct A1 Enamel shade was placed just short of the prepared margins and occupied approximately two thirds of the remaining depth of the preparation.
Figure 6. Tetric Color White (Ivoclar Vivadent) was placed with a brush and light cured.	Figure 7. Translucent composite resin, Empress Direct Trans 30 (Clear) completed the restoration to slight over-contour.

Figure 8. Postoperative view of minimally invasive aesthetic restorations using Empress Direct Composite Resin System.

The existing composite resin was removed on the right central incisor using an egg-shaped diamond (Figure 2). The preparation design using this diamond was saucer-shaped, with the depth in its center approximately 0.7 mm, tapering to a shallow depth at the margins. The preparation was feathered and scalloped another 1.0 mm beyond the outline of the white lesion (Figure 3). Anesthetic was not used in this case. This acted as a “guide” to the depth of the preparation, since there was no need to prepare into the dentin layer.
The preparation, including enamel beyond the margins, was etched with 37% phosphoric acid for 20 seconds, then washed and dried. Since no dentin was exposed, an enamel bonding resin without hydrophilic monomers or solvent was placed and light cured.
A recently introduced NSCS (Em­press Direct [Ivoclar Vivadent]) was selected for use in this case. Since the combination of the dentin and enamel of the natural tooth yielded a shade of A1, A1 Dentin, and A1 Enamel were chosen. No recipes, or combinations of a darker dentin and lighter enamel, were needed.
The A1 Dentin was applied on the white spot area only and occupied about one half the depth of the preparation. Because of the opacity of the dentin composite resin, the white spot was no longer visible (Figure 4). After curing, the A1 Enamel was applied. This increment of material occupied approximately two thirds of the remaining depth of the preparation and extended to just short of the prepared margins. Before light curing, multiple grooves and surface irregularities were sculpted with a thin bladed instrument (Figure 5). A small amount of Tetric Color white (Ivoclar Vivadent) was then placed with a brush and light-cured (Figure 6). Depth and lifelikeness was then achieved by the application of a translucent composite resin (Trans 30 [clear]), which completed the restoration, leaving it slightly over-contoured. This layer also extended beyond the prepared margins (Figure 7). Finishing and polishing steps were accomplished using aluminum oxide discs and the Astropol (Ivoclar Viva­dent) system. The patient was pleased with the result (Figure 8).

CASE 2
History and Diagnosis

Figure 9. An 18-year-old female presented with prominent white spot lesions on maxillary central incisors.

An 18-year-old female patient was referred to our office for evaluation by her orthodontist. She reported dissatisfaction with visibly prominent white spots located in the incisal one third of both her maxillary central incisors (Figure 9). It is important to note that it is often difficult to determine preoperatively how much these opacities penetrate the surface. Some lesions can be removed with micro­abrasion and repolished. Others will be deeper, ending somewhere within the enamel layer. Still others can penetrate totally through the enamel layer (as in Case 1 above) requiring restorations upon removal, or partial removal.

Clinical Technique

Figure 10. Appearance after supervised take-home bleaching was done.	Figure 11. Same preparation design as in Case 1. The lesion was entirely removed at a depth of 0.3 mm to 0.4 mm.
Figure 12. Empress Direct Enamel Shade Bleach L was applied to the preparation.	Figure 13. Appearance of restoration at approximately 2 weeks postoperatively.

The patient desired a lighter color for her teeth so dentist-monitored bleaching was carried out at home using a custom-fabricated tray. Although the contrast between the white areas and the tooth color following bleaching was reduced somewhat, their opacity still interferes with a pleasing natural appearance (Figures 10).
After taking the shade (Empress Direct Enamel Shade Bleach L [Ivoclar Vivadent]), the white lesion was gradually removed using and egg-shaped diamond without local anesthesia. At a depth of ap­prox­imately 0.3 mm, the lesion was completely gone. The preparation design was saucer-shaped and beveled at the margins as in Case 1 (Figure 11). Since no dentin is being replaced, and there was no discolored area to be blocked from view with an opaque composite (dentin), the missing enamel was replaced with Empress Direct Enamel Shade Bleach L only (Figure 12). Although this system contains the necessary 3 opacities to treat a broad range of conditions, the opacities selected are determined by the requirements of the case and the tissues being replaced. The shallowness in this case obviated the need for a layer of translucent composite. Following finishing and polishing, the patient was pleased with the outcome (Figure 13).

LONGEVITY AND RATIONALE

Figure 14. The patient desired to have the spaces closed and the central incisor restored.	Figure 15. Composite was added to the distal of tooth No. 9, the distal of tooth No. 10, and the mesial of tooth No. 11 (Esthet·X, DENTSPLY/ Caulk). The photo was taken 10 years post-op.

My experience with the previous generation of composite resin materials (before the year 2000) led me to believe that 6 to 10 years was a reasonable aesthetic longevity expectation for anterior restorations. These new materials, which are available in 3 opacities, multiple shades, and exhibit natural opalescence and fluorescence, have less polymerization shrinkage and significantly better physical properties. When properly bonded in functional harmony, the new nanomicrohybrid and nanocomposite materials should be expected to give 10 or more years of excellent service (Figures 14 and 15).
Properly bonded ceramic materials (these materials have also im­proved significantly in recent years) can still be expected to yield a greater aesthetic longevity when compared to composite resins. However, it is important to understand that these 2 materials, composite resin and ceramic, do not “compete” with each other in a treatment plan—they serve to complement each other. The lon­gevity, cost, function, extent of cosmetic change, outcome de­sired, and age of the patient are just some of the considerations for the dentist and the informed patient to weigh when selecting a treatment approach.

CONCLUSION
It is a great time to be a dentist! The public is obsessed these days with health and beauty, and we can deliver both. The aesthetic and restorative value of today’s composite resins is high. These wonderful newer materials are easy to use, and any dentist can learn to master the techniques in a short time.
I am convinced that competence in aesthetic anterior direct composite resin significantly improves a dentist’s ability to provide superior aesthetic anterior indirect services. The reason this happens is because the clinician’s understanding of opacity, translucency, value, color, form contour, and texture becomes refined to the point that lab communications become more specific and complete. You com­municate more be­cause you see more. In addition, dentists skilled in composite resin are able to modify temporary ve­neers to more accurately act as a template for the final veneers.
I would encourage every dentist to take the time to investigate these new NSCS available in the marketplace and attend hands-on courses to learn how to use them more effectively. Not only will you attract more new patients, and perhaps extend more services to existing ones, you will experience the satisfaction of creating beauty with your own hands. Finally, because pa­tients see that you were the only one involved in creating their enhanced smile—you will receive more than gratitude from them—you get admiration.

Dr. Jackson maintains a private practice in Middleburg, Va, emphasizing comprehensive restorative and cosmetic dentistry. He is a Fellow in the Academy of General Dentistry, an Accredited Fellow in the American Academy of Cosmetic Dentistry, a Diplomate in the American Board of Aesthetic Dentistry, and is director of the Advanced Adhesive Aesthetic Dentistry and Anterior Direct Resin Programs at the Las Vegas Institute for Advanced Dental Studies. He has published many articles on aesthetic and adhesive dentistry and has lectured extensively across the United States and abroad. He has presented at all the major US scientific conferences. He can be reached at (540) 687-8075 or email ronjacksondds@aol.com.

Disclosure: Dr. Jackson was a paid consultant for DENTSPLY/Caulk and Ivoclar Viva­dent during the development of Esthet·X and 4 Seasons respectively. He receives no in­come from the sales of any of the products mentioned in this article.