Dr. Robert Margeas talks about new dental materials and techniques
Dr. Dalin: As dentists, we are bombarded constantly by mailings, articles, and advertisements about new materials and techniques.
Dr. Dalin: As dentists, we are bombarded constantly by mailings, articles, and advertisements about new materials and techniques. It is becoming difficult for dentists to stay current on this information. How should we tackle this problem?
Dr. Margeas: Jeff, that is a great question. Every day someone tries to sell us something new or unique. We must be informed about why we are using a particular material or product. In my practice, I try a product based on a recommendation of a lecturer or colleague whom I respect. If I am having clinical success, I will stay with that product. I usually do not change if the results I am achieving are clinically excellent. I read numerous journals, ranging from peer-reviewed to monthly periodicals. Believe me, there are numerous products that work exceptionally well in the same categories. Clinical studies can be manipulated to achieve the results that a company wants. Technique can play more of an important role than the actual product. If you trust the manufacturer, you may be inclined to use several of the company’s products. I think we must use all the information we can to make an intelligent decision.
Dr. Dalin: Let’s talk about the different categories of dental materials and how we should go about choosing a product that works best for our patients. In regard to restorative resins, what properties should we look for and what questions should we ask manufacturers when choosing this system for our offices?
Dr. Margeas: There are several classes of restorative resins from which to choose. They include hybrids, microhybrids, nanofills, and microfills. Some manufacturers use new terminology to sell products. There are advantages and disadvantages of the different classes of materials. The first two (hybrids, microhybrids) can be lumped into one category. They offer strength and opacity but have less ability to be polished. They are great for lingual backing and incisal edge strength. They also work well in the posterior. The microfills offer more translucency, better handling, and have an excellent ability for polishing. Strength is their weakness. The nanotechnology is getting closer to creating a material that has strength and the ability to be polished. I don’t feel we are quite there yet. They are much better, but do not hold a polish like the microfills. Most clinicians will accept the newer nano composites because of ease of use. In the anterior, I still prefer a sandwich technique. I use the hybrid type or nano material for strength and opacity, and overlay with a microfill material for the translucency and ability to be polished. The most important features are handling, strength, the ability to be polished, and color stability. Therefore, I want a material or materials that will give me these qualities. I use Cosmedent’s Renamel hybrids and microfills, along with tints and opaques to achieve a natural result. If you only want to use one material for the entire procedure, 3M ESPE’s Filtek Supreme Plus, Coltene’s Synergy D6, GC’s Gradia Direct, Bisco’s Aelite Aesthetic Enamel, Ultradent’s Vitalessence, and Kerr’s Premise are materials to consider. I have had the opportunity to try them, and they all handle well.
Dr. Dalin: While we are on the subject of restorative resins, let’s discuss bonding agents. Earlier this year on these pages, I spoke with Dr. Jeff Brucia. He had some fascinating information to share about the newer generations of bonding agents. What properties should we look for and what key questions should we ask when considering this system for our offices?
Dr. Margeas: In my practice, I use two different bonding systems. One is a fifth generation bonding agent for my direct restorations. It is a one-bottle system after I etch the enamel and dentin. My choices of material are One-Step Plus from Bisco, Single Bond from 3M ESPE, and DENTSPLY’s Prime and Bond NT. There are certainly other excellent materials from which to choose, but these are the ones I use regularly. For my indirect restorations, chemical-cure material, and self-cure material, I use a fourth generation system. The one I have been using for more than 15 years is All-Bond II from Bisco. I trust Byoung Suh, founder and president of Bisco dental products, to manufacture excellent products. I think it is important to have faith in manufacturers. Other excellent choices are 3M’s Scotch Bond Multi Purpose, Kerr’s OptiBond FL, and Cosmedent’s Power Bond. I etch the enamel and dentin, then apply a primer and a separate adhesive. The fourth generation bonding agents are the most universal. For me, they work for every clinical situation. They are much more technique-sensitive and require additional steps and time. The bond strengths to enamel and dentin are quite high. In the last 15 years, more clinical studies have been done with this class of material than any other. It is considered the gold standard. There is no reason for me to change from a fourth to a seventh generation because I have had long-term clinical success. That is the most important factor to me. The questions I ask are: Does the material work in all clinical situations? Does the material etch enamel adequately? What are the bond strengths? I can see why numerous clinicians love the self-etching primers and adhesives. They create minimal to no sensitivity and are not technique-sensitive. This category of bonding agents has had the most growth in the last five years. Not all self-etching primers and adhesives are the same. Some are not strong enough to etch enamel. Those that do etch enamel well have shown more promising results. The ones I have tried that have produced good desensitizing are Tyrian (Bisco), Preclude SE (Danville Engineering) and Simplicity (Apex Dental). Most all-in-one bottle systems are not stable over time, so I do not use them. I may be old-fashioned, but I use what gives me the most long-term clinical success. The extra time it takes to use a fourth-generation material is well worth it in terms of long-term clinical success. I do feel dentin bonding will degrade over time. Therefore, I try to maintain and use as much enamel to which to bond.
Dr. Dalin: What are your thoughts about impression materials?
Dr. Margeas: The main classes of impression material are polyethers and polyvinylsiloxanes. You can achieve excellent results with either material; it just depends on the properties you are seeking with that material. Polyethers are hydrophilic. They work well in moisture, and have less tear strength. The polyvinylsiloxanes offer higher tear strength but are hydrophobic. Surfactants are added to improve the ability to remain wet. The properties I look for in an impression material are good dimensional stability, adequate working time, flowability, high tear strength, and excellent detail. I also like a material that will allow the preparation to be fully covered by the light body and not have the heavy body or tray material force the light body out. That is why I prefer Affinity from Clinician’s Choice. Other impression materials I have tried and recommend are DENTSPLY’s Aquasil and Cosmedent’s new Impressive. The most recent material to hit the market is a vinyl-polyether hybrid called Senn from GC. Remember, if you have excellent technique, you can use an array of materials to achieve a successful clinical result. I have used these materials successfully.
Dr. Dalin: Temporary cements are materials we use that can make our practice lives easy or difficult. What are your recommendations in this category?
Dr. Margeas: I prefer a temporary cement that keeps a provisional restoration in place but allows me to remove it easily prior to cementing the permanent one. I don’t want to use a material that sticks too well to the preparation. Generally, I use a noneugenol cement. My material of choice is Zone (Cadco). Clinician’s Choice Cling 2 is another product to consider. When I want to use a long-term provisional, I prefer a temporary resin cement such as TempBond Clear from Kerr. For cementing a permanent restoration temporarily, I recommend Flow Temp from Premier Dental. I think it is the most underutilized cement in dentistry. The clinical situation in which it works best is when you have a patient who has had sensitivity with a provisional, and you are not sure about whether to cement the final restoration permanently. Use Flow Temp and you can remove the restoration easily, but it will not come off on its own. I have used this product for several years, yet no one seems to know about it.
Dr. Dalin: This interview would not be complete without discussing permanent cements. What suggestions can you offer about these materials?
Dr. Margeas: I have been using resin-reinforced glass ionomer cements since they were first introduced several years ago. The results have been outstanding. They are easy to use and cleanup is excellent. They work with porcelain-to-metal, gold, and the newer zirconium crowns. My favorite is Fuji Plus in the automix capsule from GC. Another excellent cement is 3M’s RelyX Luting Plus. They cannot be used with pressable or stacked glass crowns. I have cemented numerous crowns with the self-etching, priming, and bonding resin cements. I have had good results with them. They are easy to use since most practitioners don’t like to etch, prime, bond, and cement separately. They are all-in-one resin cements. You do give up bond strength for ease of use. Unicem (3M), Maxcem (Kerr), and Embrace (Pulpdent) are the cements I have used the most. Bisco’s BisCem shows well in clinical tests. More clinical trials are necessary before I will make this the material of choice for all of my restorations. For veneers and etched porcelain restorations, I prefer a resin cement with a fourth generation bonding agent. For more than 10 years, I have used Insure from Cosmedent. The handling and cleanup are ideal.
Dr. Dalin: Are there any other points regarding dental material and techniques that you wish to share with our readers?
Dr. Margeas: You can use the best materials on the market and still have failures. Technique will always play a major factor in our clinical success. Remember, the magic is not in the magic wand but in the magician. Be leery of a product that sounds too good to be true. Research it yourself before jumping in with both feet. Reality and CRA are publications that can give clinicians insight on the thousands of available dental products.
Dr. Dalin: Bob, thank you for taking the time to provide this valuable information. When our readers walk through the exhibit halls at their next dental meeting, they will be ready to do some informed shopping. They will have some good background information about what they should be looking for, and will have useful questions to ask before making decisions to purchase.
Dr. Margeas: Thank you for allowing me to share my thoughts on these topics. I hope it has been beneficial.
Dr. Robert Margeas graduated from the University of Iowa College of Dentistry in 1986, and completed his AEGD residency the following year. He is an adjunct professor in the Department of Operative Dentistry at the University of Iowa. Dr. Margeas has developed several dental products. Dr. Margeas is co-director of The Center for Advanced Dental Education in Des Moines, Iowa. He maintains a private practice in Des Moines that focuses on comprehensive restorative and implant dentistry. He can be reached at (515) 277-6358 or via e-mail at firstname.lastname@example.org.
Jeffrey B. Dalin, DDS, FACD, FAGD, FICD, practices general dentistry in St. Louis. He also is the editor of St. Louis Dentistry magazine, and spokesman and critical-issue-response-team chairman for the Greater St. Louis Dental Society. He is one of the co-founders of the Give Kids A Smile Program. Contact him by e-mail at email@example.com, by phone at (314) 567-5612, or by fax at (314) 567-9047.