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    Inside Dental Technology

    February 2013, Volume 4, Issue 2
    Published by AEGIS Communications


    The Secret to Custom Shade Matching

    Visualizing and navigating to desired results

    Luke S. Kahng, CDT

    Restoring a single anterior tooth is always a challenge for clinicians and technicians when it comes to custom shade matching. Selecting the correct color depends on the colors represented in the adjacent teeth. If the adjacent teeth have a great deal of color, then that indicates low value and detailed differences between those colors. They can be light, medium, or dark in interior color with crack lines and other characteristics that make matching the color a very difficult task. Surface textures can also present a challenge to the technician. This article will illustrate how to take a custom shade, demonstrate one type of material selection and restorative technique in detail, exemplify a step-by-step ceramic layering process, and show dental technicians how to finalize the restoration surface texture with a natural glaze.

    Case Study

    The author created a ceramic shade tab system inclusive of crack lines to distinguish colors within the A3 zone to try and match tooth No. 8 (Figure 1). The underlying preparation color is very important in determining the definitive color, especially when there is a lack of facial room. In cases like these, because the restoration will be translucent after layering, the coping seated in the patient’s mouth should have the same tone and hue, which is an important consideration when matching preparation color (Figure 2). At the try-in stage, dental technicians are given an important starting point and are asked this question: Can we achieve the same saturation and balance of tooth color variation (Figure 3)? The author started with the platinum foil technique when creating this restoration. The translucent paper was used as a platinum foil guide and as a measurement for tooth size (Figure 4). The paper was cut to shape as it was wrapped around the die (Figure 5), and then the foil was cut to size (Figure 6).

    After the foil was cut, it was then pressed onto the die (Figure 7). As the author worked, he pressed the foil even more firmly to the die (Figure 8). Using tweezers, he carefully shaped the form of the die before cutting the wrap closely (Figure 9).

    A plastic stick was used to press deeply into the margin area; the author further prepared the foil (Figure 10). Unnecessary foil was carefully cut away with scissors (Figure 11 and Figure 12) and shaped and wrapped accordingly (Figure 13 and Figure 14). The final cut made the foil quite small (Figure 15). Using tweezers, the author then finalized the technique (Figure 16). In the final step, the foil was burnished (Figure 17). After burnishing, the author measured the results again and decided to cut away even more excess foil (Figure 18). Using a metal stick, he was able to completely smooth down the edges of the foil over the die (Figure 19) until complete and even coverage was achieved (Figure 20).

    When ceramic layering, the author gets best results from GC Initial™ Low Fusing Porcelain (GC America, www.gcamerica.com) (Figure 21). His first step was to apply dentin in an A3 color and inside dentin No. 41 (Figure 22 and Figure 23). Next he layered EOP4 (enamel opal) over the top (Figure 24). After cutting back, he applied Translucency Modifier 01 (Figure 25.) Low Fusing Translucent Modifier-05 was applied next (Figure 26). Grey translucency overlay was applied over the mesial, distal, and body areas (Figure 27 and Figure 28). The next step was to apply Enamel 13 in order to create a white stain (Figure 29). Over the Enamel 13 application, he layered Enamel 57 (Figure 30). Next, the author placed the layered restoration on the die in order to bake it for the first time (Figure 31). After firing (IBEX Summit porcelain oven, IBEX Dental Technologies, www.ibexdental.com), the restoration exhibited a nice translucent appearance (Figure 32).

    The restoration was tried on the model for a fit check (Figure 33). Cervical translucency powder was applied (Figure 34) in formula No. 24. Translucency neutral was then applied (Figure 35), and a line was drawn down through the porcelain in order to create a crack line with a white stain (Figure 36). The restoration was baked again at 780°C (Figure 37), and the interproximal contact was checked on the model (Figure 38).

    Surface texture markings were created (Figure 39) with a marker, after which the author used both thin and thick diamond disks to create irregular vertical and horizontal surface texture lines (Figure 40). Using Pico-Fit gold die spacer (Renfert USA, www.renfert.com), the author applied his final texture to the surface (Figure 41). With tweezers, he was able to carefully remove the remaining foil from the restoration (Figure 42). In a mirrored image, we can see the irregular surface texture between the teeth in the incisal area (Figure 43) as well as crack lines and mamelon. On the model, a mirrored image is again displayed (Figure 44).

    Next, the restoration was tried in the mouth. At this time, the technician could see the balance of color versus the adjacent teeth and positioning of the restoration (Figure 45 and Figure 46). Occlusal views with dehydration demonstrate the harmonized balance of color and tone (Figure 47 and Figure 48). Upon immediate insertion, we see the same translucency and reflection of size and lobe as the natural adjacent teeth (Figure 49). The convex area of the teeth is an almost perfect match with the patient’s dentition.

    Conclusion

    In order to achieve excellent custom shade matching results, we need proper navigation and an appropriate visualization of the outcome before we get started with the case. We also need to see the patient dehydrated and hydrated in order to take both into consideration as we create the restoration. Translucency (meaning grey, light grey, and clear coloring) or opacity (meaning orange, brown, pinkish grey, or yellow coloring) has to be decided beforehand as well. Crack lines are an additional task to be decided upon, and so is surface texture. Without those considerations, we will not have a matching restoration.

    We look to the adjacent teeth for answers. Once we get them, it is not too difficult to adjust accordingly and create a match.

    About the Author

    Luke S. Kahng, CDT
    Owner
    LSK121 Oral Prosthetics
    Naperville, Illinois


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    Image Gallery

    The author created a ceramic shade
tab system.

    Figure 1

    After-preparation color plays an
important role in the case fabrication.

    Figure 2

    Try-in stage.

    Figure 3

    The author began the platinum foil technique.

    Figure 4

    The author began the platinum foil technique.

    Figure 5

    The author began the platinum foil technique.

    Figure 6

    Foil is pressed onto the die as closely as possible.

    Figure 7

    Foil is pressed onto the die as closely as possible.

    Figure 8

    Tweezers were used to shape the form.

    Figure 9

    A plastic stick was pressed deeply into the margin area.

    Figure 10

    Unnecessary foil was cut away.

    Figure 11

    Unnecessary foil was cut away.

    Figure 12

    Shaping and wrapping.

    Figure 13

    Shaping and wrapping.

    Figure 14

    Final cut.

    Figure 15

    Foil is delicate and sticks together easily.

    Figure 16

    The foil was burnished.

    Figure 17

    Excess foil was cut away.

    Figure 18

    A metal stick was used to smooth the foil.

    Figure 19

    Illustration cover of foil.

    Figure 20

    LF porcelain was used for ceramic layering.

    Figure 21

    Add dentin A3 and inside dentin No. 41.

    Figure 22

    Add dentin A3 and inside dentin No. 41.

    Figure 23

    EOP4 was layered over the top.

    Figure 24

    Translucency Modifier 01 was applied after cutback.

    Figure 25

    Translucency Modifier 05 was then applied.

    Figure 26

    Grey translucency overlay was applied over the mesial, distal, and body areas.

    Figure 27

    Grey translucency overlay was applied over the mesial, distal, and body areas.

    Figure 28

    Enamel 13 was applied to create a white stain.

    Figure 29

    Enamel 57 was applied over Enamel 13.

    Figure 30

    The restoration was placed in the porcelain oven.

    Figure 31

    The restoration exhibited
a translucent appearance after firing.

    Figure 32

    The restoration was tried on the model.

    Figure 33

    Cervical translucency powder was applied.

    Figure 34

    Translucency neutral was then applied.

    Figure 35

    White stain was applied to create a crack line.

    Figure 36

    Restoration was baked at 780°C.

    Figure 37

    The interproximal contact was checked on the model.

    Figure 38

    Surface textures were created.

    Figure 39

    Thin and thick diamond disks were used to create irregular vertical and horizontal lines.

    Figure 40

    Renfert gold die spacer was used to create the final texture on the surface.

    Figure 41

    Remaining foil was removed.

    Figure 42

    Irregular surface texture between incisal area crack line and mamelon can be seen.

    Figure 43

    Mirror image on the model.

    Figure 44

    The restoration was tried in the mouth.

    Figure 45

    The restoration was tried in the mouth.

    Figure 46

    An occlusal view with dehydration.

    Figure 47

    An occlusal view with dehydration.

    Figure 48

    Immediate insertion.

    Figure 49