The esthetic cosmetic age

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The esthetic cosmetic age
2007
DPR World

Computerized and conservativeÛthese are the two buzzwords of todayÌs cosmetic/restorative realm, with CAD/CAM and minimally invasive protocols leading the way.

DPR: What have been the hottest prosthodontics topics this year?

Dr. Cranham: The first is CAD/CAM restorations, both lab-fabricated and chairside.

Also hotÛlayering porcelains, such as Venus (Heraeus Kulzer). They can be used to fabricate veneers and inlay- and onlay-type restorations, but also can be layered over pressed ceramic or zirconia substructures. WeÌre also seeing IPS e.max (Ivoclar Vivadent), a similar type of porcelain, designed to go over different foundational materials. With such materials, weÌll be able to create a uniform look but with a wide variety of different materials based on the patientÌs functional needs.

As to layering porcelains with chairside CAD/CAM technology, it depends on how advanced you want to get with it. There are doctors trying to create the most beautiful anterior restorations. TheyÌll mill and then cut back a little bit and then layer so they have gradients of color. Most chairside CAD/CAM restorations are either polished and inserted, or minimally stained and glazed. With patients who need the highest-end esthetic multichromatic restorationÛin other words, all my anterior casesÛthatÌs when I do a lab-fabricated restoration. I take a regular impression and send it to a lab.

Dr. McLaren: WeÌre in an evolutionary, rather than revolutionary, period.

In the last few years, we had a revolution with CAD/CAM systems and newer materials. So thereÌs nothing totally brand new except, potentially, for digital impression taking. But relative to the final restoration, itÌs all newer or Ïme-tooÓ systems that are improving or coming on the market.

The trend in restorative dentistry, though, is back to conservatism. WeÌre cycling back to minimal or no-prep veneers. No-prep veneers have been on the market for at least 20 years; they were just never a hit. Then Lumineers porcelain veneers (Den-Mat Corp.) came on the market. For this to resurface is a great opportunity, because of all the industryÌs buzz.

ThereÌs also a trend to go to more direct bonded restorations rather than to crowns, certainly to more zirconia restorations rather than metal-based restorations. ItÌs fascinating in dentistry how everything cycles. Now, occlusion is a hot topic again; it was hot in the Ì70s and sort of disappeared.



"A general practitioner should
become an expert at esthetic
and cosmetic dentistry."



-Dr. John Cranham
Director of Education, Dawson Center for
Advanced Dental Education
In the next year or two, there will be a new revolution in digital impression making. ThereÌs been a system on the market for a few years called OrthoCAD (Cadent) that takes digital scans of patient mouths and provides a digital model, which helps in placing braces. Cadent also recently introduced the iTero handheld digital impression scanner for chairside use. Sirona is looking at something with their imaging system. The technology takes a virtual digital impression so you donÌt have to do a physical impression anymore.

And 3M ESPE bought Brontes Technologies, a developer of 3-D intraoral imaging technology. Brontes is now working with rapid prototyping, so you wouldnÌt even have to make a model. This came from the orthodontic industry, where essentially, digital information would generate the model, coping, and restoration. ThereÌs really no physical model made in the whole process, unless it will be machined from a rapid prototype in a CAD/CAM system just like we machine a coping.

There also are systems coming out now where the dentist doesnÌt have to make a temporary. They image it, and then it would go to some rapid prototyping machine that would spit out a temporary, assuming you even need to make one.

IÌve even heard of technology offering the ability to see through soft tissue to hard tissue, so that you wouldnÌt have to pack cord. You would prepare a tooth, and letÌs say you had a subgingival preparation. In the future, you wouldnÌt have to pack the cord. You could see through the soft tissue, much like sonar sees through water and shows hard or metal structures at the bottom of the ocean. These technologies are on the drawing board.

While costs are similar to a conventional impression, with a digital impression, you can scan the tooth before preparation. Then, once you prep, you can look at the scan and judge the amount of reduction to see whether you took out enough tooth structure. Systems will be extended to where you can do the smile design and project where the teeth are going to end up in three dimensions. Then the computer can essentially see backward from that.

LetÌs say, for example, that you were going to build up the teeth just slightlyÛ maybe make them a millimeter longer. The computer would then do that virtually. When you start prepping, it would tell you after youÌve scanned it again that youÌve got a millimeter-and-a-half space or whatever. ItÌll tell you if youÌve got undercuts. Hopefully, it will minimize some of the problems with either under- or over-preparation, undercuts, and poor impressions. I see that as a true revolution in restorative dentistry in the next year to five years and beyond. Again, relative to the final restoration, itÌs more an evolution of whatÌs already on the market.

The trend again is going to be more CAD/CAM and less actual manual labor. ThereÌs a system being developed by some CAD/CAM researchers outside of dentistry. With this system, the dentist would essentially scan the patient or import the images, and the computer would design the smile, the temporaries, the shell temporaries. YouÌd start prepping, and then image the preparations. Then the final temporaries would show up, or you could reline the temporaries. ThereÌs a couple of ways to do that. The entire process is digital, from the coping to the first layer of porcelain applied, maybe even to the second layer of porcelain. In the future, maybe your high-end ceramist is just going to be doing little touch ups of porcelain and the final contour to add a little artistic flair to it. The computer is doing 80% to 90% of the work.



DPR: Any new significant products or techniques in your specialty this year?

Dr. Cranham: One notable new product for the everyday general practice is the Protemp Crown Temporization material (3M ESPE). Basically, it allows assistants to get a stock crown (it almost looks like a crown form except itÌs composite thatÌs still kind of malleable), put it over the tooth, kind of pat it in place, and cure it for a couple of seconds. You can take a novice assistant and teach her how to make nice single-unit provisional restorations efficiently.

Another intriguing product is Spirapost (Zenith Dental). IÌve always been very conservative in post placement, but when you need a little extra retention for your core, I really like the design of this flexible-type post (it almost looks like a brush going into the tooth). It creates minimal stress, but does a nice job retaining the core. You still have to have 2 mm for the ferrule effect. You still have to follow the requirements of good post placement.

The other big area is hard- and soft-tissue lasers. IÌve been using a diode now for a couple of years, and the combination of the diode laser with Expasyl (Kerr Corp.) retraction paste has just about replaced retraction cord in my practice. Whether itÌs for tissue recontouring or just creating a small trough around the tooth prior to placement of Expasyl, a conventional impression material, or a digital type impression, the diode laser is a big adjunct to the practice.



DPR: What message would you most like to get to the GP?

Dr. Cranham: ItÌs the best time ever to be a dentist. We have a population of patientsÛthe baby boomersÛwho are aging slowly. TheyÌre the first population group who donÌt expect to lose their teeth at some point in their life. And most of them didnÌt have the benefits of fluoride. They have a lot of restorations, and want to look their best. So when we combine their want for a beautiful smile with the help they need to keep their teeth (and health and function) for a lifetime, the result is an unbelievable opportunity for dentists. This means that we need to deliver good, solid dentistry to provide boomers with beautiful esthetics and help them chew their food until the day they die. We also have to realize that this is a smart population. They do their research and have Internet access. To take care of them, we have to stay up-to-date on the latest concepts, procedures, and materials.

Dr. McLaren: Relative to fixed prosthodontics, I would look at being more conservative, maybe even more than dental schools are. We really should be looking at doing more bonded porcelain. My clinical guideline (and you know what guidelines are) is flexible, depending on the patientÌs condition. But my guideline is: I want 50% enamel remaining on the tooth. It could be on the lingual, the facial, or anywhereÛitÌs something to add stiffness to the tooth, and then IÌll do bonded porcelain. If there is less than 50% enamel on the tooth, especially down around zero, IÌm thinking about doing a crown. That would be the moral for fixed prosthodontics today.

I also would be looking at implants, whether or not youÌre going to place them. I never tie into natural teeth; I never did. With implants, I always did everything freestanding. So, if IÌm missing three teeth, I put in two implants and a three-unit bridge. IÌd be doing more implants and partial bridges. And I would be doing single crowns. If I have to do a bridge today, almost universally, itÌs not going to be any bigger than three units. If itÌs bigger than that, IÌm always adding implants. I donÌt even do the case if the patient doesnÌt want an implant and wants me to do a six-, seven-, or eight-unit bridge. ItÌs better for everybody, and itÌs a cost-effective way to go long term. We know implants work, if theyÌre designed correctly. Their success rate is phenomenal if everything is done correctly.

From the perspective of practicing general dentistry, weÌre really entering that area of Ïwants-basedÓ dentistry; dental ÏneedsÓ are going to decrease with caries control. So a general practitioner should become an expert at esthetic and cosmetic dentistry because weÌre all appearance-motivated, and itÌs a fun area of clinical practice.

I also would develop a skill in adhesive dentistry. Get away from doing amalgam and direct composites. Master bonded porcelain, porcelain veneers. Also master posterior composites, which is direct dentistry. Keep as much of the heathy tooth structure as possible. Think about form, fit, function, and beauty. If composites are done correctly, they do very well. They do as well as an amalgam, if all techniques are followed. Technique sensitivity is very high for composites, compared with doing an amalgam (which you could put in with your thumb in the presence of blood or saliva).

IÌd also become good at visual documentation with some form of camera, and also with visual patient presentations. WeÌre all very visual. None of us would spend $40,000 or $50,000 on a car without touching and driving it. ItÌs no different in dentistry. In some way, you have to give the person the perception of actually taking their teeth for a test drive using digital imaging or some type of digital manipulation. There are wonderful programs out there you can buy for this. Or you can send them to places like Smile Vision or other companies that will take your image, do a smile design for you, and send it back so you can show the patient what it would look like.