Veneers for improving darker teeth
An acceptable esthetic outcome may not always require increasing the thickness of the overall veneer, thereby conserving precious tooth structure, authors publishing in the August 2014 issue of the Journal of Esthetic and Restorative Dentistry reported.
Often used to improve the appearance of front teeth, the long-term success of ceramic laminate veneers is gaining with continued improvements in adhesive bonding techniques. However, treating discolored anterior teeth remains challenging for clinicians.
Opacity is a function of veneer thickness and effectively masks discoloration. However, the technique requires a more destructive preparation to enable adequate ceramic thickness. High-strength laminate veneers have demonstrated good masking ability for darkness without compromising tooth structure. Research also shows improvement in esthetic predictability may be enhanced by using different layers of ceramic at predetermined thicknesses.
Finding only a few studies assessing the masking ability of multi-laminate veneers, a team of scientists from Germany, Australia and the United States compared the masking ability of bi- and tri- laminate all-ceramic veneers cemented on tooth-colored ceramic discs.
Scientists made 40 discs to simulate teeth. Half of the ceramic discs were made in shade A1, and the other half in shade A4. They then created 40 veneers of shade A1 (10-millimeter diameter, 0.8 mm thick), 20 bi-laminate (BL) and 20 tri-laminate (TL), and cemented them on the differently colored ceramic discs. They measured the color of the cemented veneers using a spectrophotometer.
Masking ability of an all-ceramic restoration is measured by the color difference when placed over different backgrounds. Results showed that the color differences between the samples with the A1 and A4 ceramic bases were significantly lower when covered with TL veneers than with BL veneers, indicated that the TL veneers had better masking ability, according to the authors.
The researchers used veneers thinner (0.8 mm) than those recommended for discolored teeth (1.2—1.4 mm) to test the capabilities of the ceramic system.
“Suggested preparations of 1.2—1.4 mm are clinically unlikely due to the excessive loss of tooth structure,” the authors said. “Thinner veneers with a comparable esthetic result may be a solution for darker teeth.”
Authors also noted that previous studies have largely concentrated on how the thickness of ceramic affects its masking ability, thus disallowing comparison with the present investigation.
Composite shade guides and matching color
Although the perfect shade guide may remain forever elusive, researchers in Italy may be a step closer to that reality with a study they published in the Summer 2014 issue of The International Journal of Esthetic Dentistry.
For their research, they examined the characteristics of commercial shade guides and current evidence on color matching in dentistry. They also constructed their own custom-made shade guide and evaluated its reliability.
The authors identified problems that make it difficult for clinicians to identify reliable ways to match the color of a restoration. These problems include lack of unification in composite shade nomenclature and multiple variables between available composite systems. The authors found shade guides dissimilar to each other in the following ways:
- material of the shade guide;
- type of support for the shade-guide specimen;
- shape of the specimen;
- thickness of the specimen.
“A standardized custom-made shade guide, with a variable enamel thickness width and a tooth shape, can help the clinician to better understand the material’s behavior,” authors said. “The clinician can easily reproduce the tooth’s shade, knowing the composition of the matching specimen.”
Composite enamel thickness is known to play a central role in the esthetic outcome, so the research was based on composite enamel shells, which served as the study specimens.
To investigate, scientists fabricated and provided step-by-step instructions for producing a custom-made shade guide with a micrometer. To verify whether the specimen’s thickness could be influenced by material type, they analyzed different composite resin brands and included 16 composites (enamel and incisal) of different brands.
Every specimen was measured in the cervical, middle and incisal areas in order to evaluate thickness. Results showed that except for one specimen, there were no significant differences between the specimens in the cervical measurement, none across the measurements taken at the middle area and two when the measurements were taken at the incisal area of the composites.
The researchers found “significant clinical advantages,” when using the custom-made shade guide they produced. For example, classic shade guides are composed by layered tabs, but the user does not have control on the enamel shell.
The authors believe the study could represent a valid contribution for clinicians because it examined different brands of composite resins, demonstrating that matching shades among different systems could be available with predictable layer thicknesses.
Ivoclar Vivadent brings back Just Cure It!
Ivoclar Vivadent announces that for the second year, $100 will be donated to breast cancer research for each pink Bluephase Style curing light sold during the month of October. Our award-winning Bluephase LED curing lights provide a great resource for dental practices, Ivoclar Vivadent believes that donating a portion of the proceeds to Breast Cancer Research provides a great resource for finding a cure.
Measuring translucency in dental materials
Methods used for describing the translucency of dental materials may provide information useful to a clinician’s selection, yet current guidelines for such description don’t exist.
A review published in the August 2014 issue of the Journal of Esthetic and Restorative Dentistry describes methods for translucency measurement, an overview of applications and also suggestions for measuring dental materials based on both color science and recent dental literature.
“All of the mainly used determinations of translucency, i.e., CR, transmittance, and TP, each require that a thickness be specified and the specification of this thickness is usually dependent on clinical opinions of importance,” the author reports.
The literature showed that translucency measurements were mainly used to describe dental resin composites and dental ceramic materials. However, prosthetic elastomers, fibers posts, orthodontic brackets, natural tooth dentine and enamel and combinations of materials also were studied using at least one of the three methods.
The current study focused on literature published after 2008, despite the fact that much earlier research about translucency has been performed.
“Methods of determining the translucency of natural and esthetic restorative dental materials have seen significant advances, but technical details might limit the comparisons of previously published works to any newly generated research,” according to the report.
Masking with lithium disilicate bonded restorations
A case study showing what the author calls an “outside-the-box technique” for providing consistent, predictable, durable and esthetic restorations was published in the Summer 2014 issue of The International Journal of Esthetic Dentistry.
The author, Yugo Hatai, is a registered dental technician and master ceramist. Reproduction of the natural dentition without the influence of a “negative stump” (a very dark or metal core showing through the final restoration) is one of the most significant challenges in metal-free dentistry, according to Mr. Hatai. He said controlling the opacity of the coping and crown are critical among factors that must be considered.
The reconstruction of a single central incisor that had been traumatized and had a very dark non-vital stump with a gold core was the focus of the study. The patient, in his thirties, had been treated with multiple porcelain-fused-to-metal restorations by different clinicians—a common circumstance, said Mr. Hatai. He said the patient has never been satisfied with the outcome.
A smile photo and a full face photo were used to determine the esthetic zone, in addition to the clinical dental photos, and used in communications between the clinician, technician and patient during the treatment planning stage, as “patients relate better to these photos,” Mr. Hatai explained.
“The patient,” he said, “is the ultimate judge of the final outcome of restorations in the esthetic zone, a factor of which dental professionals must always be aware. In other words, if it does not look good to the patient, it does not matter how it looks to the dental team.”
The report proceeds with step-by-step selection of suitable materials and procedures, as the authors keep patient perception top-of-mind.
“Even untrained eyes (such as the patient’s) can detect differences in value quite easily, so it was critical to have the correct value, whereas slight variations in hue and chroma might be forgiven in various circumstances.”
In general, the higher the translucency, the lower the value or relative lightness or darkness of the hue. During shade taking, the hue and value was established first as these factors influence the ingot selection. Because chroma could be easily added during the build, it was deemed important to keep the substructure at lighter shades to maintain its value—“particularly important when sufficient thickness cannot be maintained—the thinner the restoration, the higher the translucency, and the higher the translucency, the lower the value.”
Another consideration was the tendency of layered translucent porcelain to drop the restoration’s value.
The method for pre-operative assessment, shade taking, fabrication and assessment of the coping and crown, surface treatment and bonding procedure and completed restoration for the specific technique are included in the report, as well as an examination of a traditionally layered ceramic crown versus a two-piece bonded ceramic restoration.
Ivoclar Vivadent launches ‘More Than a Denture’ websites
Ivoclar Vivadent, a world leader in materials and processes for quality esthetic dentistry, has launched its “More Than a Denture” consumer and professional websites.
Designed to make today’s innovative solutions for removable dentistry easy for patients and professionals alike, the websites emphasize a simple and predictable approach for creating smiles that are comfortable, durable and natural-looking. At the heart of the “More Than a Denture” system are Ivoclar Vivadent Removable solutions.
The “More Thank a Denture” websites are extensions of the company’s successful patient education campaigns and online professional resources. The consumer-oriented website www.morethanadenture.com features a variety of real-life stories that denture patients can relate to, as well as easy-to-understand information guiding patients through the denture selection and fabrication process.
“Most denture wearers don’t realize that there are choices when it comes to the quality of their dentures,” says Dr. Michael Gaglio, vice president of Ivoclar Vivadent. “That’s why Ivoclar Vivadent has created a patient education site to better inform patients about their options.” Among other features, the site offers an assortment of patient education materials—from a reception-area video to brochures.
“To help dental professionals achieve better results, Ivoclar Vivadent has created a professional site that not only informs dentists about better materials and processes, but also connects the clinician and laboratory through an Authorized Ivoclar Vivadent Removable Laboratory list,” notes Dr. Gaglio.
A dental laboratory also can become an Authorized Ivoclar Vivadent Removable Laboratory directly through the website at
Announcing IPS e.max Lab Finder!
Ivoclar Vivadent introduces its IPS e.max Lab Finder, a new resource to help dentists locate more than 6,000 laboratories in North America currently using the clinically proven IPS e.max all-ceramic system. Created in response to demand from dentists to identify laboratories that can fabricate IPS e.max crowns, inlays, onlays, thin veneers, abutments, and bridges. IPS e.max Lab Finder enables dentists to work with laboratories already skilled in utilizing IPS e.max materials to deliver great-looking and durable restorations for their patients.
ADA offers discount on dental veneers brochure
Now through Oct. 15, the ADA is offering members a patient education brochure on dental veneers at a 15 percent discount.
Members can order “Dental Veneers” (W288) through the ADA Catalog, using promo code 14362E. The six-panel brochure is available in packets of 50 for $26; retail price, $39. Discounts also are available in higher quantities.
The brochure focuses on the benefits of veneers and outlines reasons to choose veneers, using before-and-after photos and illustrations of veneer placement. It also explores the benefits of porcelain-versus-composite veneers and placements steps.
Members can preview this and other ADA brochures online at adacatalog.org. Orders can be placed online or by calling the ADA Member Service Center at 1-800-947-4746. Remember to use promo code 14362E to receive the 15 percent discount.
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