First Impressions: February 2009

Written by George Freedman, DDS Sunday, 01 February 2009 00:00

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

EXA'lence
GC America

Dentists have faced a major dilemma in selecting impression materials; vinyl polysiloxanes have excellent wettability and good tear strength, while polyethers have excellent wettability and great flow. Dentists have split into 2 camps: 75% use polyvinyl and 25% use polyether, and never the twain shall meet. Most polyvinyls are actually too hydrophobic to work well in the always-wet environment of the gingival sulcus. Voids or folds in the final impression from bleeding and crevicular fluid are due to poor hydrophilicity and poor flow, and low impression material strength allows marginal tears during removal. GC America has introduced EXA'lence, a new category impression material, an intrinsically hydrophilic vinyl polyether siloxane combining wettability, tear strength, and flow into a single material. EXA'lence is not repelled from moist surfaces, actually adapting to them. No surface reactants are required. Its excellent elasticity permits easy removal and multiple pours. Thin areas around clinical margins do not tear, and EXA'lence's detail provides great accuracy and fewer retakes/remakes. From the lab perspective, EXA'lence is compatible with any disinfection procedure. A range of colors (allowing clear margin visibility) and viscosities (for various clinical techniques) are available. EXA'lence provides accurate impressions even in a moist environment, overcoming the clinician's major concerns of bleeding, adequate sulcular performance, and gingival trauma, thus decreasing chairside stress and enhancing restorative results. EXA'lence's thixotropic properties and flowability allow it to be placed or pushed subgingivally, picking up the finer details, and then to be removed without tearing; it handles like a VPS with polyether detail. EXA'lence provides an accurate and detailed reproduction of the tooth preparation for a predictable fit with minimal or no adjustment. For more information, call (800) 323-7063 or visit gcamerica.com.

Calset Composite Warmer
AdDent

As the dental profession has warmed to composite use, we have learned to warm our composites prior to use. The Calset concept has been discussed in First Impressions previously, but it was available for compules only. AdDent has now added several practical accessories for warming composite and anesthetic syringes to the system. These versatile units can be used to heat composite syringes to 54º or 68ºC and to warm anesthetic carpules to body temperature—37ºC.

(The trays are sold separately.) As the temperature of a composite restorative is increased, its viscosity is lowered, thereby increasing the flow. This increased flow makes a regular microhybrid composite behave very much like a flowable, adapting more closely to the marginal morphology and the irregularities of the cavity preparation. Heating composites has been shown to reduce the required light-curing time by up to 80% while concurrently increasing monomer conversion. Warm composite also offers a greater depth of cure. Importantly, the increased efficiency of curing, multiplied by the many curing procedures that dentists perform every single day, results in decreased chair time per restoration and higher overall productivity. Warmed composites exhibit higher diametral and tensile strengths and greater microhardness, enhancing both the physical and mechanical properties of the finished restoration. The harder the composite, the better the restoration. Composite properties are not negatively affected by heating (and cooling, even repeatedly), and composites can stay in the warming unit indefinitely. The Calset unit takes about 10 minutes to preheat at the beginning of the day and can be left on continuously. Once the Calset unit is warm, approximately 2 to 3 minutes are required to warm the composite syringe. For more information, call (203) 778-0200 or visit addent.com.

ComfortView Lip and Cheek Retractor
Premier Dental Products

Cheek and lip retraction used to be a dental photography concern. Effec-tive retraction provided better, clearer pictures and more effective before-and-after and educational comparisons. (For promotional purposes, retracted cheeks are not an ideal marketing tool.) Today, in-office bleaching, anterior aesthetic dentistry (ceramic and composite), and the prevalence of tooth-colored restorations all require effective cheek, lip, and tongue retraction. These procedures require (1) teeth to be free of saliva and moisture for extended periods of time and (2) soft tissues to be protected from caustic bleaches. Not all cheek and lip retractors are created equal. The issues include patient comfort, dentist utility, and cost per use. Premier's new ComfortView Cheek and Lip Retractor offers a unique approach to isolating the anterior dentition and providing total dental access while keeping the patient completely comfortable. It is a nonthreatening appliance that retracts the cheeks and lips and keeps the mouth open yet protects the patient's tissues with replaceable cushions. Placement is very straightforward. Lubricate the lips with petroleum jelly prior to insertion. Contract the vertical lip holders. Insert one lateral lip holder inside the patient's cheek until the pink cushions rest on the anterior vestibular area and the upper cushions rest adjacent to the frenulum. Then, gently guide the retractor's other side just inside the cheek by slightly bending it. Lift the lips and verify patient comfort. Begin the procedure. The Comfort-View may cost more than other appliances, but the unit is sterilizable and reusable. Disassemble for effective cleaning. Remove debris and clean with a mild detergent. Both retractor and cushions are steam autoclaveable. Reassemble after sterilization. (Cold sterilization is not recommended). The Comfort-View offers the practitioner visibility and the patient comfort. For more information, call (888) 773-6872 or visit premusa.com.

InFibra Ribbon System
Global Dental Products

The dental profession has utilized a variety of wires and fibers for splinting and dental reinforcement for hundreds of years. The more recently developed tooth-colored dental fibers have many clinical indications: periodontal splinting, spacers, fixing bridges and prostheses, composite resin reinforcement of mobile teeth, temporary stabilization of artificial teeth, shorter-term provisional bridges, and orthodontic retainers. Global Dental Products has recently introduced the InFibra Ribbon System, a splinting product that is fabricated from highly crystallized white and polyethylene longitudinal fibers. These fibers have been selected to provide mechanical characteristics that are ideal for specific dental use. The fibers are interlaced, allowing a neat cut of the fiber where necessary. (Frayed ends are always difficult to embed completely in composite resin.) The interlacing effect creates a 3-dimensional fiber anatomy that permits the cord to be completely padded with composites, unfilled resins or acrylic resins. InFibra is available in widths of 2, 3, and 4 mm, assuring its utility in a wide range of dental procedures. It is important to remember to use clean (preferably dedicated) tweezers for retrieving the fibers. In addition, the fibers must not be touched without gloves (dermal oils can reduce their adhesion to resins). Special cutting scissors must be used to cut the desired fiber length. Then, InFibra is wetted with bonding agent prior to use and placed onto or into the teeth with a flowable composite (for acrylic resins, wetting the mono-mer). In general, fibers and fiber ends should not be exposed to the oral environment. Fibers must be covered completely with composite resin. Should wear begin to expose the underlying fiber, a new layer of composite can be added to avoid fiber exposure. For more information, call (516) 221-8844 or visit gdpdental.com.

ResiCam
Shofu Dental

As patients become aware of the profession's ability to eliminate metal from their crown and bridge procedures, they are increasingly de-manding ceramic restorations. The current ceramic framework materials (zirconia and aluminum) are not like their earlier counterparts in handling and operative characteristics. Cementation procedures, critical to long-term success, are also affected. Shofu Dental's ResiCem has been designed specifically for the zirconia and aluminum restorations. The AZ primer, ensuring excellent bond values between the restoration and the tooth structure, was developed for alumina and zirconia. The monomer (6-MHPA), specifically adapted for high-performance porcelains, anchors firmly to the restoration, providing consistently strong bonds. ResiCem bonding alumina- and zirconia-based restorations is straightforward; simply sandblast the alumina, apply AZ primer, and let air dry 10 seconds. Then, combine equal amounts of primers A and B, apply to the tooth, leave undisturbed 20 seconds, and air dry. Apply the automix ResiCem paste directly into the crown, insert with finger pressure, lightcure margins, and remove excess paste. Excessis is easily removed without smearing or sticking. ResiCem's flowability ensures complete wetting of the abutment, while its 9 µmμfilm thickness offers an excellent marginal fit and bonding strength, without affecting the occlusion. Not having to adjust the finished restoration is clinically very efficient and comfortable for both patient and dentist. The double-barrel single-push syringe ensures that the mix is always precise. The tiny syringe tip improves application accuracy and minimizes cement overuse. Marginal color adaptation is crucial to the success of an indirect restoration. ResiCem's clear color is translucent, offering highly aesthetic margins regardless of cement thickness. ResiCem is also radiopaque; the cement's extent and any subsequent redecay can be readily differentiated. For more information, call (800) 827-4638 or visit the Web site shofu.com.

TherOzone T-1000
TherOzone

The advantages of using ozone for disinfection in medicine and dentistry are well established. Ozone decontamination has been common in hospital settings for almost a century, and it is used routinely in the food and health sectors as a disinfectant for edible products and working surfaces. While ozone at 1 ppm will kill bacteria and viruses on contact within a matter of seconds, the FDA recognizes up to 5 ppm of ozone as a food additive. The recently introduced T-1000 unit from TherOzone is a countertop device that quickly and safely dissolves ozone gas into ordinary distilled water. The ozonation cycle for an entire standard dental unit water bottle takes only a few minutes. The process is virtually automatic; a single button initiates the entire process. TherOzone provides 3 to 4 ppm of ozone in distilled water, useful for dental procedure irrigation, presterilization, surface and appliance disinfection (partials, full dentures, and orthodontic appliances). TherOzone ozonated water has a half-life of 30 minutes at room temperature. The ozonated water bottle may be plugged directly into the dental unit waterline to create a bacteria-free water supply that is to be delivered into the oral cavity during dental procedures (through handpieces and water syringes). The T-1000's redundant safety systems eliminate any risk of operator exposure to ozone gas; the unit cannot generate ozone until the sealed bottle is securely locked into place. A special filter converts excess ozone (O3) gas to oxygen (O2). Remember not to overfill the bottles with distilled water. While dissolving ozone into the water, some units make a mewling sound. This is simply a function of the valves working properly, not a problem. For more information, call (310) 581-5585 or visit the Web site therozone.com.

Dr. Freedman is past president of the American Academy of Cosmetic Dentistry, is the Materials & Technology Editor for Oral Health, and is the Materials Editor and author of the monthly section "First Impressions" for Dentistry Today. 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. Dr Freedman 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, dental technology, and photography. A graduate of McGill University in Montreal, Dr. Freedman maintains a private practice limited to Esthetic Dentistry in Toronto, Canada. He can be reached at (905) 513-9191 or This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

First Impressions: February 2009

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