Smiling With Confidence: The Balance of Opacity and Translucency
Choosing the most appropriate material is essential
Selecting the appropriate material for restoring a patient’s smile is the most important decision the dental team makes when diagnosing and evaluating a case. Whether fabricating and seating a single crown or an entire arch, the responsibility for determining if patients smile with confidence or hide their smiles in public or in an intimate moment with friends or loved ones rests with the dental team (Figure 1 through Figure 3).
One of the biggest challenges facing the dental team is finding a balance between opacity and translucency when restoring a patient’s smile. Opacity is very powerful for blocking out dark dentin in a prepped tooth. A highly opacious material will block all light, preventing the dark color of the dentin from escaping underneath. However, highly opacious materials will not absorb sufficient natural light for the restorations to appear "alive." Light transmission over the entire restoration is just as important as the translucency in the incisal edge. Translucency is critical for creating life-like restorations. Faced with a dark stump color, many technicians choose an opacious ingot or coping and build it up extensively by segmenting powders in multiple layers. Such an approach is not appropriate for patients with an underbite or end-on-end bite.
Fortunately, technicians today have myriad choices when it comes to selecting the appropriate material for the case indication. Ivoclar Vivadent (ivoclarvivadent.com) has introduced IPS e.max, a line of pressable lithium disilicate materials that exhibits both strength (400 MPa) and natural-looking esthetics. For technicians, it has become increasingly important to have a material that can deliver natural-looking esthetics without spending excessive time at the bench.
The patient was a 48-year-old woman who desired a natural-looking, white smile. The treatment plan called for placing six maxillary crowns on teeth Nos. 6 through 11. For restoring this case, the author chose to use the IPS e.max Multi-Press BL2 shade with minimal internal effects.
The sprueing of IPS e.max Press Multi requires the use of a new sprue base designed to achieve a horizontal flow path of the material (Figure 4). This ensures the shade gradient visible in the ingot is maintained throughout the pressing cycle. The sprue may be adjusted higher or lower on the base to control the amount of translucency achieved.
The author pressed the restorations in the EP5000 pressing furnace using the proprietary IPS e.max Multi pressing program (Figure 5 through Figure 7). The restorations were cut from the sprue (Figure 8), using an end-cutting disc to minimize head buildup. A red pencil was used to indicate the margin, and the internal surface was marked with lipstick. Then a stone wheel was used to refine the mesial interproximal area where the sprue was applied to the restoration and the margin was polished on the die. The author smoothed out the surface with a medium round bur.
Surface texture is applied more aggressively to create secondary anatomy using a tapered diamond and a spiral bur, then polished to remove any sharp angles or excessive grooves (Figure 9). A variety of e.max Ceram shades and essence materials was used to customize the case to meet the patient’s esthetic demands (Figure 10). IPS e.max Ceram Shade Incisal 2 was used to help absorb light along the incisal one-third, and Essence E18 anthracite was placed to separate the mamelon effect and mimic the translucent effect of the halo. E05 Copper and two parts E20 rose were blended and placed where the gingival tissue would come in contact with the IPS e.max crowns to reflect the life of the tissue into the restoration. E02 Crème Essence was used for the light reflective portion of the halo, and a small amount was used to warm up the cervical center of the tooth. The restorations were then fired (Figure 11).
After firing, Glaze Paste was placed in a mixing bottle. One-third of the paste was introduced into the mixing container and one drop of glaze medium was added and the two were mixed together. The Glaze was placed over the restorations in excess, then removed until the brush strokes appeared to remain and then slowly disappeared, giving a smooth surface (Figure 12). The crowns were fired again, this time using the IPS e.max Glaze program. The author then used a soft diamond to smooth out any rough areas and polish the crowns to the dentist’s desired texture. The high shine was restored with a high-shine disk (Figure 13 through Figure 15).
Ivoclar Vivadent has revolutionized dentistry with its new IPS e.max Multi-Press ingots. Replicating a porcelain buildup, the homogenous gradient pressing block allows technicians and dentists to concentrate their time on the finite details of creating life-like esthetics.
Dane Barlow is a member of the American Academy of Cosmetic Dentistry and the Chief Operations Officer and Director of All Ceramics for Smiles Inc.
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