First Impressions: September 2008

Dentistry Today

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In First Impressions, Dr. George Freedman, DDS, gives readers a brief summary of products that have recently been introduced to dentistry, based on his clinical experience.


 

 

 

N’Durance
Septodont Materials Division

In the ongoing search for better composite restorative materials, the practitioner often encounters situations where actively improving one parameter is necessarily at the expense of another. Such has been the case with monomer conversion rates and volumetric shrinkage, two simultaneous processes that are integral parts of the photo polymerization of light-cure dental composite materials. Generally, a higher conversion ratio (molecules that convert from monomers to polymers during photo polymerization) is desirable for a stronger, more resistant restoration. Greater volumetric shrinkage tends to stress adhesive interfaces and promotes marginal leakage and restoration failure. Unfortunately, as the conversion ratio increases, so does the volumetric shrinkage. Septodont’s N’Durance is a universal composite restorative material that utilizes 2 distinct new technologies: nanotechnology and a proprietary dimer acid chemistry. The nano-dimer conversion technology provides a very high intraoral monomer conversion ratio while maintaining a low volumetric shrinkage (approximately 1.4%). Its low volumetric shrinkage during polymerization, and thus low polymerization stress, means reduced stress at the bonding interface of the tooth (at both the enamel and the dentin), offering greater marginal integrity and durability. The high degree of polymerization can be achieved even with fast curing times. The highly radiopaque nano-filler is readily differentiated from both enamel and dentin. N’Durance’s nano-dimer technology improves compressive and flexural strengths as well as the wear resistance of the restorative material, making it an excellent choice for a universal dental restorative material. N’Durance is available in 16 VITA shades (plus opaque and bleach white), all with an exceptional polishability, allowing the material to blend in with surrounding dentition.
For more information, call (800) 872-8305 or visit the Web site located at septodontusa.com.

iCem Self Adhesive Resin Cement
Heraeus Kulzer

Cement: a material that adheres two dissimilar materials to each other such that they cannot readily come apart. In dentistry, cements must also be biocompatible, preferably adhere (bond) to enamel, dentin, and restorative materials, and provide a seamless aesthetic and durable transition at the tooth-restoration interface. Heraeus Kulzer’s innovative iCem Self Adhesive resin cement combines the easy handling and humidity tolerance of traditional cements with the superior mechanical properties and aesthetics of resin cements. iCem is a true one-step resin cement. It bonds (etches, primes, conditions, desensitizes), adheres, and seals within a 6-minute total cure. There is no drying, rinsing, or waiting. iCem is less technique-sensitive than many other cements on the market. No separate etching step and no dentin drying (desiccation) ensure low postoperative sensitivity. Dual-curing iCem polymerizes with light (within 20 seconds) and/or after automixing (within 6 minutes). It exhibits excellent microtensile bond strength and excellent shear bond strength. It al-so has excellent tensile bond strength when used to bond titanium posts into tooth structure. The technique is very simple: rinse the prepared tooth (remove excess moisture until slightly moist), automix iCem into the dry crown or bridge, and insert. Light-cure the margins, remove the excess cement, and finish the margins once set. GLUMA desensitizer can be used as a wetting agent for the tooth prior to applying the iCem self-cure adhesive resin cement. (iCem is a dual-cure resin and as such is not indicated for veneers, Maryland bridges, low-fusing all-ceramic restorations, and feldspathic all-ceramic restorations.) iCem universal one-step res-in cement: one fast step and you are done.
For more information, call (800) 431-1785 or visit the Web site located at heraeus-kulzer-us.com.

V3 Ring
TrioDent

TrioDent’s original V-Ring System, a matrix system specifically designed for composite materials, made the restoration of interproximal spaces far easier, more predictable, and considerably faster. TrioDent’s new V3 Ring has improved on this great concept. The new V3 Ring is made entirely from nickel titanium, which is super-elastic, providing outstanding spring strength and memory. The V-Ring’s stainless steel component has been eliminated. (Steel rings tend to expand over time and lose their ability to separate teeth effectively.) The V3 Ring consistently delivers optimal separating force and returns to its original shape, providing greater longevity and predictability for tight contacts. Two V3 Rings were developed, one for premolars and another for molars, to ensure ideal separating forces on both sizes of posterior dentition. The premolar V3 Ring ensures optimal separating forces on smaller teeth. According to Hooke’s Law, the ring extension is proportional to the applied force; there is 50% less force on a premolar than a molar when using the molar separation ring. The autoclavable matrix has glass fiber-reinforced plastic tines for better retention and superior adaptation, creating an ideal cavity restoration form that minimizes finishing time. The plastic segment also provides a positive seat for the forceps, offering more stability during placement and removal of the ring. (Standard rubber dam forceps may be used.) The V3 Ring’s wedge tunnel permits the introduction of the wedge from buccal or lingual, before or after ring placement. The spring has also been tilted on its axis away from the marginal ridge of the tooth, allowing more room for simultaneous ring placements on adjacent teeth. Interproximals are a snap with the V3 Ring.
For more information, call (800) 811-3949 or visit the Web site located at triodent.com.


NTI-TSS Plus
Keller Laboratories

The use of occlusal guards to alleviate the intensity of clenching, particularly at night during sleep, has been well-established for many years. There are several ways to ap-proach this problem. The 2 most common include full or partial coverage of either the upper or lower arch. The stated objective for an occlusal guard is to prevent patients from clenching and stressing their muscles during times of unintentional parafunction. (Some have even suggested that full-coverage night-guards may increase the intensity of temporalis activity by providing an ideal clenching surface.) NTI-TSS Plus from Keller Laboratories prevents posterior contact and is designed to greatly reduce muscle contraction intensity. The advantages are that the NTI-TSS Plus guards are much smaller than full-coverage guards, typically covering only the anterior teeth. The gag reflex is not triggered, providing better compliance because patients are more comfortable wearing the appliance. It requires fewer adjustments, saving valuable chair time. The appliances are very durable. They are made from Keller’s Clear 450 thermoplastic material. Clenching is reduced immediately on insertion, relaxing the muscles and reducing pain for most patients. The NTI design provides instant and constant incisal guidance in the following areas: protrusive—the lingual extension maintains incisal contact and prevents posterior contacts, decreasing muscular activity in all movements; centric—the instant incisor contact reduces muscular contraction intensity and allows for optimal and stable condylar position; and excursive— the height and the contour prevent canine contact on the teeth or appliance, maintaining suppressed muscular intensity and joint stability. NTI-TSS Plus is an excellent al-ternative to full-coverage day- or night-guards.
For more information, call (866) 535-5371 or (800) 325-3056, or visit the Web site located at kellerlab.com.


Great White Z Diamonds
SS White

Indirect dental restorative materials have come a long way in the past 25 years. The state of the art used to be a porcelain-fused-to-metal (PFM) restoration. Today, there are many indirect options, including metal, PFM, ceramic, and zirconia. Some of the most recently introduced aesthetic materials include zirconia crowns and copings. These materials are extremely strong and can be made aesthetically pleasing but can be very difficult to manipulate with existing burs. In fact, standard diamonds have a very difficult time cutting, penetrating, or even adjusting zirconia restorations. SS White has introduced its revolutionary Great White Z Diamond kit specifically developed for adjusting and penetrating zirconia restorations of all types. The Great White Z burs were designed with advanced engineered diamond technology that provides maximum cutting efficiency for zirconia and ceramic crowns, bridges, or substructures far more easily and with less effort than with standard diamonds and carbide burs. The kit provides specialty shapes for slot crown removal techniques, endodontic access, and crown and bridge adjustment. The kit contains 2 round diamond burs, one medium and one large for endodontic access, a round-end tapered diamond for removing crowns, and a football-shaped diamond for adjustment procedures. They are packaged in a convenient, labeled, autoclavable bur block organizer. Rapid cutting and access preparation are particularly important for patient comfort as well as dentist convenience. Great White Z Diamonds cut through zirconia quickly and effectively, eliminating the frustration that the practitioner often encounters by during these procedures. Great White Z Diamonds are the hard and fast solution for cutting through zirconia.
For more information, call (800) 535-2877 or visit the Web site located at sswhiteburs.com.

Pentamix 3 Automatic Mixing Unit
3M ESPE

Automatic impression mixing units have revolutionized the art and science of impression taking and generally have made clinical dentistry easier and more efficient. Since precision impressions are critical steps in providing high-quality restorations to patients, simplifying and improving the impression process enhances the entire indirect restoration treatment. The Penta-mix 3 is 3M ESPE’s latest entry into the automated mixing field. It has one of the smallest footprints of any electronic impression mixing system, thus requiring the least amount of counter space. Its compact size is made possible by a unique, powerful, chain-driven system that possesses the mechanical strength to dispense all dental impression materials, including putties. The most innovative feature is its faster speed of mixing; it dispenses material ap-proximately twice as fast as the Pentamix 2. This faster mix provides the practitioner with increased working time, decreasing the stress of the impression-taking process while optimizing the success of impression taking. The Pentamix 3 allows the rapid and efficient ex-change of loaded cartridges through an improved design for manual plunger retraction. It is even possible to replace an exhausted cartridge in the midst of filling a tray. Multiviscosity impressions are now possible with the same automatic mixing unit and the same impression tray. The activation controls are conveniently accessible by both right- and left-handed operators, enhancing the operational efficiency. Automix impressions tend to provide better restorative results (versus hand-mixed materials) because they deliver a homogeneous material that has smaller and less bubbles that can cause errors in the restoration. The Pentamix 3 does it faster as well.
For more information, call (800) 634-2249 or visit the Web site at 3mespe.com/greatimpressions.

Dr. Freedman is past president of the American Academy of Cosmetic Dentistry and is the Materials Editor for Dentistry Today. He is the Chairman of the Clinical Innovations Conference (London, UK) as well as the Dental Innovations Forum (Singapore). He is the author or co-author of 11 textbooks, more than 400 dental articles, and numerous CDs, video and audiotapes, and is a Team Member of REALITY. He is a past director of CE programs in aesthetic dentistry at the Universities of California at San Francisco, Florida, UMKC, Minnesota, Baylor College, and Case Western Reserve and was the founding associate director of the Esthetic Dentistry Education Center at the State University of New York at Buffalo. He is a co-founder of the Canadian Academy for Esthetic Dentistry and a Diplomat of the American Board of Aesthetic Dentistry. He lectures internationally on dental aesthetics, technology, and photography. A graduate of McGill University in Montreal, Dr. Freedman maintains a private practice limited to aesthetic dentistry in Toronto, Canada, and can be reached at (905) 513-9191 or epdot@rogers.com.