LSK121 Oral Prosthetics

Regardless of price, many patients are looking for answers to their esthetic needs. They know technology will allow them even better results than ever before. Thanks to the demand, dental professionals are always looking for better options to meet these needs.

Fortunately, the same technology that has created the demand also enables exciting new possibilities. One of the best restoration options for these esthetically challenging cases is metal-free zirconia. With this type of restoration, porcelain butt margins can be avoided while maintaining maximum strength in the restoration. With a milling machine in-house and the proper color in a zirconia block, a beautiful metal-free substructure can be created.

This article illustrates the technician’s steps in matching custom shade coloring for an esthetic case.

?Custom shade tabs were used for color matching.

?Amann Girrbach Ceramill Motion Mill 2. 

, the patient’s initial custom shade appointment indicated 50% opacity, gingival and body color with translucency modification to the gingival, body and incisal color. The proper tool was used for custom shade taking, using three different colors -Y5, Y6 and Y7 for youthful coloration with 50% opacity, white calcification and translucency included in the porcelain tab.

 The clinician’s prep design used an ovate pontic design that worked well with the technician’s plan of action making success more accessible (

 machine then designed and milled the zirconia with accurate 5-axis precision within the milling machine (

 After milling, the sprue was cut with rubber (

). The sprue was then removed, and put back for the pre-shading stage (

 After sintering, the color difference can be observed (

). At the same time, implant abutments can be created for a four-unit bridge, which is both efficient and cost-saving because one zirconia block is used for the whole process.

) with one color for one powder layering was used (

). After firing at 810°C, the three-unit bridge had the appearance featured (

?50% Opacity, GC One Body One Color Porcelain

 After contouring, lustre paste was applied and fired at 780°C. From the gingival 1/3 and the body an incisal illusion was created by using a brown coloring in this stage (

). For 3 units, the amount of lustre paste color differed because there are more units involved (

). In the mirror image the gingival 1/3 cervical color is bright while the pre-molar color is darker in shade. Interproximally, they are the same (

).  By using various lustre paste colors, a different coloration within the restoration was created that was not monochromatic in color. This does not follow the “A1/A2 coloring” seen in most restorations, but the goal is a natural, life-like restoration, which is never monochromatic in appearance.

), the white horizontal lines, and the brown, orange tones were checked to make sure they had been naturally mimicked. Half-way into the mouth a photo was taken to give a different view of the mouth, partly closed (

). It was then thought the restoration might require a little more stain, which could be examined more closely in the mouth (

). A decision was then made to try and see how the appearance changed. Ultimately, it was decided that there was too much translucency so the stain was removed before baking the restoration.

 An immediate try-in reveals a natural looking restoration with beautiful tissue (

). The dentist in the case is a periodontist and took special care of the tissue for the patient. The color, balance and design are all in alignment.

The important point in this case is not to worry about custom shading. There are many solutions and a lot of answers for those who seek them. The use of multi-layering can yield excellent results but many times it is unnecessary. The one-body color achieved with 

 is all that is needed for these esthetic accomplishments. Once one is able to figure out the opacity of the adjacent dentition and identify the color characteristics between the teeth, they can likely get the final results they seek with this product-at least 40% of the time. Not only are the results beautiful, the technique is efficient and effective. Both the patient and clinician will be pleased with the results, thus reaching the final goal successfully.

This article originaly appeared in the April 2013 issue of 

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Articles

Kahng on an efficient way to match color

A look at the All on 4 Denture Procedure using 

Patients with dentures almost always will become tired of the re-lining process. It has to be done frequently, and gets to be a nuisance. The ever-increasingly popular alternative to dentures, known as the All on 4 Implant System, has alleviated this problem to a large extent for patients who have suffered with dentures. Some labs fabricate All on 4 dentures but some do not. It’s a very difficult restoration to outsource because it still has to be delivered to the doctor’s office for try-ins and adjustments quite a few times, depending on the fit. In my opinion, it is wise to learn how to fabricate these restorations because they are becoming more and more prevalent within the dental community.

This article illustrates the procedure for the All on 4 technique, involving the laboratory side. It also addresses using the new 

 Super Hi Impact, a denture based resin for the edentulous area. This product makes the technician’s job much easier because the product is strong, durable and esthetically beautiful, too.

 After taking off the healing caps, the mandibular 4-unit implant site was exposed before the impression was taken (Fig. 1). The doctor can use four temporary abutments and floss material to engage the implants together. The clinician used an open-tray technique to take this impression.

 The lab technician put the lab analogs into the impression tray and created the soft tissue and poured up the model (Fig. 2).

 The bite block was pre-made with the verification index (Fig. 3) from Primotec USA’s primopattern light-cured wax.

 After curing with the temporary abutment it was ready to send to the doctor for verification in the patient’s mouth. The doctor then sends back the bite block after verifying the patient’s bite. Then it is tried and verified on the model (Fig. 4).

If everything fits properly, the clinician sends it back as is. If for any reason it doesn’t fit properly, he must fix it by cutting and patching it with resin. If it is cut and patched because it does not fit, the lab will fix it on the model, then send it back to the doctor again for a wax try-in. The wax try-in is tried on the model (Fig. 5).

 The lab’s next step is to send the wax teeth to the doctor for a try-in in the patient’s mouth (Fig. 6) to re-check the bite.

 For the final teeth production, the lab used a GC Putty Guide material, based on the wax teeth (Fig. 7) to act as a template. At this stage, it is also necessary to look at the frame design for guidance with the final restoration. GC’s Nature-Cryl resin material (Fig. 8) is high impact and convenient to use. It requires two hours of heat curing and is available in seven different shades. The material is easy to finish and polish, and resists fracturing. I created some samples of the various colors available with Nature-Cryl, demonstrating how easy it is to create special characteristics and mimic the gum tissue aspect (Fig. 9).

Fig. 7 GC Putty material as a guide. (Figs. 1-6 above)

The colors in this image are: COE-LOR Moderate (#21) and COE-LOR Heavy (#22). In the next image (Fig. 10) there is another denture sample, from a true patient’s case, this time to demonstrate frame design and the mesh metal in a light color (#34). With the All on 6 denture pictured next (Fig. 11) the finished product is a light reddish pink in color (#35) and in the next (Fig. 12) we see a mandibular denture in the original color (#36).

 The flipper for the four missing mandibular teeth (Fig. 13) was completed in COE-LOR Moderate (#21).

 Finally, we see the All on 4 finished restoration with a hybrid bar as a two-piece detachable appliance (Fig. 14) or an All on 6 one piece restoration (Fig. 15).

Fig. 14 All on 4 finished product, 2 piece detachable

As a dental technician working primarily as a ceramist, I understand and create beautiful esthetics with my porcelain layering technique. However, things are changing rapidly in the dental industry and I began to realize it was important to expand my knowledge and keep up with the newer product offerings. To that end, it is always advantageous to experiment with new dental materials as they are offered.

We have all seen cases where the patient has an upper or lower denture only, but then find that he needs to have the opposite denture placed as well. The two should match in tooth color or the effect will be displeasing in appearance. For this reason and many others, technicians should learn how to fabricate All on 4 cases using denture or ceramic teeth. It is my hope that by sharing this knowledge we can expand our product bases and serve our clients better, too. There is a whole world of new creations out there for us to take advantage of. We should learn as much as we can!

A look at the All on 4 Denture Procedure using GC’s Nature-Cryl.