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OPT-In Clinical Updates for May, 2013

• Why Dual Arch Impressions Work or Not Work

What to do About It

• New Dental Laboratory Specialties
• Technology Management, a Huge Differential
• Understanding How Adhesive Systems Work
• OPT-In Laboratory Members Near You

by

Dean Mersky, DDS

Creating Excellence, Partnering in Growth

Who are We and Why are You Receiving This?

In October, 2012, Dr. Dean Mersky formed

A national cooperative of small dental laboratory owners

Dedicated to the growth and viability of Private Practice Dental Offices.

A part of our support is providing doctors with evidence-based

information about materials and techniques key to patient care.

Look for the Logo in Choosing your Laboratory Partner

How We Decide Which Materials and Manufacturer to Feature

The products and services we feature must have benefits supported by independent research and be offered by companies dedicated to education in best practices patient care, or, provide services that support patient care at the highest levels. We understand the lines between advertisements and useful clinical information can be blurry. We make sure that is not the case. For example, we will not substantiate 24 hour bond strength reporting as useful.

Consistency with Dual Arch Impressions

Little Known Facts about Dual Arch Impressions

That can Make a Huge Difference

In Profitability and Productivity

Dual-arch impressions have been proven to provide highly accurate impressions, sometimes more accurate than stock or custom trays. Parker, in 1997 reported significantly more accurate maximal intercuspal relationships when compared to mounted casts from full arch impressions. Additionally, Cox wrote in 2005 that crowns fabricated from dual-arch impressions are equivalent in marginal accuracy and superior occlusally to crowns fabricated from the complete, single arch impression. However, all these advantages are placed at risk if we use materials or techniques not designed for dual arch impressions. Below, we will address these factors.

It All Begins with the Tray

The dual-arch technique takes less chair time, uses less material, and is preferred by patients to help prevent gagging. They have a lot of benefits, so long as the right tray is used.

Unfortunately, plastic trays easily flex and risk distortion. The lost accuracy from plastic dual-arch tray flexure can result in 180-210 micron discrepancies, according to findings reported by Carrotte et al, 1998. In fact, Cho and Chee found in 2004 that viscosity alone is enough to distort plastic trays. Several factors work against plastic dual-arch trays, including contact with the palatal or lingual tissues, or retromolar pad areas. Even patient swallowing during the setting period can distort a plastic impression tray enough to destroy accuracy of fit, contacts, and/or occlusion.

For best results, choose a highly rigid tray, like the aluminum Quad-Tray Xtreme, from Clinician's Choice. I used these in my own practice for several years, after being introduced to the company by the late Dr. Bob Nixon, one of the preeminent cosmetic reconstruction dentists of his era. Their use immediately cut seat times.

The reason they work well is due to the boxed aluminum having no elastic memory. While rigid, the Quad-Tray Xtreme can still be customized (as shown in image, above) and adapted to different arch configurations. Design features such as low sidewalls, a short lingual wall and thin distal bar prevent impingement that would cause distortion in other trays. Additionally, the Quad-Tray Xtreme’s wide arch design prevents the teeth from rubbing through the sides, as commonly experienced with plastic.

Top Left Photo: The Clinician's Choice Quad-Tray XL (Xtra Long) is a full quadrant design, extending to the midline. The tapered buccal/facial wall is perforated, and the lingual wall slotted to help lock the impression material.

Top Right Photo: In contrast to Clinician's Choice trays, notice how the plastic tray frame can be easily bent by anatomy or the tongue during the impression, and then subject to rebound.

Contra Indications and Lab Guidance for Dual Arch Impressions

Certain situations, such as group function occlusions, do not lend themselves to simple dual-arch impressions. Terminal tooth preparations and group function occlusions can lead to occlusal inaccuracies and long seat-times when mounted to plastic hinge articulators, as discussed by Thorton in 2002. Dual-arch impressions with a terminal tooth preparation are best mounted to a metal articulator, while group function occlusion is best managed with a mounted full arch impression. Another helpful note is for the dual-arch case to be mounted to a plastic base with pinned dies to increase and maintain accuracy during fabrication. Last, standard dual-arch impressions should be limited to 2 preparations, while the extended, Quad-Tray XL can be used for up to one, 3-unit bridge.

"When using an impression material that is specifically designed to be used with the dual arch tray the researchers observed 12 times the accuracy in the maximal intercuspal position with the dual arch cast."

Mitchell SA Journal of Prosthodontics Oct 2009;18:585-588

Use an Impression Material Designed for Dual Arch Impressions

Clinician's Choice offers an ideal dual arch, heavy body, impression material, Affinity InFlex, the first material developed for the dual arch technique. With a low 1.3% strain in compression value, and durometer hardness of 80-82, Affinity InFlex is stiffer and stronger than putty and heavy body materials.

Affinity Light Body is the syringe material perfectly matched to work with the stiffness of Affinity Inflex, illustrated in the photo, right. There are three types of Affinity Light Body: RF (shown at right), High Flow, and Extra Lite. We will spend time explaining their unique characteristics in future editions.

Setting Times are not What We Think and can Lead to Remakes

Drags, pulls, inaccuracies, and distortions can all be the results of not understanding what manufacturer reported setting times really mean. First, we need to understand the difference between setting time, and working time, and how the two can actually vary from what has been reported.

Clinical Tip

Drags, pulls, inaccuracies, and distortions can all be the results of not understanding the true meaning of “manufacturer reported setting times.” In fact, the differences between setting times and working times, and how the two will vary, can be confusing when compared to what manufacturers have reported.

Notice the pulls in the photo, left.

Another error to avoid is mismatching light and heavy body materials. Differences in setting times can lead to material gaps, as illustrated in the photo, right. To help avoid gaps, both materials need to remain fluid and unpolymerized when seating the impression tray.

Next Month
In future editions, we will review how to solve common impression-taking problems, different impression materials offerings, and explain proper techniques, which can often be confusing: putty vs. heavy body, single phase vs. two-phase impression techniques, etc.

If you haven't yet tried Clinician's Choice Quad trays and Dual Arch impression materials, based on their use in my practice, please do. You're in for a pleasant surprise!

Visit Clinician's Choice

http://www.clinicianschoice.com/posecom/

Call Toll-free 800-265-3444

You can submit questions or find the right laboratory for your practice by contacting us at:

info@optindentallab.com

855-321-OPTN (6786)

or visit our website at:

http://www.optindentallab.com/

It Should be Easier to Find the Right Dental Laboratory

OPT-In Dental Laboratory Specialties

OPT-In Laboratories are grouped by their specific expertise

To simplify finding

The right laboratory for your needs.

OPT-In Esthetics

• Specialty in multi zone layering and internal staining with attention to the details of vital blending, contours, anatomy and texture for the most demanding esthetics  

OPT-In Implants

• Experience in complex implant cases, including fixed-removable, full-mouth fixed and removable implant restorative, milled bars, and various attachments and complex designs

OPT-In General Practice

• Dedicated to the daily needs of general practice and the wide variety of everyday requirements dentists face, for an equally wide variety of clinical criteria and budgets

OPT-In Prosthetics and Full Mouth Reconstruction

• Expertise in removable prosthetics, including simple and precision partial denture designs, and standard to complex over-dentures. This group is also familiar with a variety of occlusal approaches and articulators used in reconstruction

OPT-In Orthodontics

• Provides all aspects of orthodontic laboratory services from the simplest to the most complex

Learn More about OPT-In Laboratory Specialty & Expertise

BEGO Certified

Visit

http://www.optindentallab.com/dentists/services/choose-a-laboratory-specialities/

BEGO Advanced Technology 2.0

Digitally Designed

Laser PFM Copings & Milled Ceramics

BEGO USA's 2.0 Technology Center

Why Choose Digitally Designed Laser PFMs

Laser sintering eliminates the variables and inconsistencies of metal castings. That's why close to 50 million Select Laser Melted (SLM) copings have been manufactured world-wide. It eliminates waxing, investing, and casting that are all subject to inaccuracies caused by stresses and distortion. Moreover, because the process is CAD/CAM managed,  finished products can be designed to  improve fit by dialing in margin tolerances, specific cement gaps, consistent wall thicknesses, and maintain greater density, all important factors for porcelain strength.

Bridge is sitting upside down to illustrate the superb retention and fit at the margins of BEGO SLM.

BEGO, the leader in SLM crown & bridge production, developed the process over 12 years ago.

BEGO USA's 2.0 Technology Center: Now, All-Ceramics

Technology and materials can be standardized. Unfortunately, their management is not and is the reason all milled end products, even the same products and brands, are not the same. BEGO Certified is different because BEGO meets your laboratory's criteria specifications.

All laboratories relying on the BEGO 2.0 Technology Center must be calibrated for integration accuracy. Each laboratory must run trial cases that are examined for narrow tolerances in fit, form, and other factors prior to becoming certified. Moreover, BEGO requires this process for each material a laboratory offers, as a BEGO Certified Partner.

BEGO USA is now offering All-Ceramic solutions, such as BruxZir.

You can find a BEGO Certified OPT-In Dental Laboratory in the listings, below.

Experience the Difference a BEGO Certified Lab Offers

BEGO is now offering Semi Precious,

SLM Copings and Bridges,

The only Semi Precious SLM Bridges available.

OPT-In Dental Laboratories are BEGO Certified

Contact us for more Information about BEGO 2.0

 Digitally Designed SLM Copings and  All-Ceramics

info@optindentallab.com

http://begousa.com/

http://www.optindentallab.com/

How Adhesives Work

With so many choices, we need

to understand the variables and what they mean.

This Newsletter is Presented by Your

OPT-In Dental Laboratory Cooperative Partner

http://www.optindentallab.com/dentists/

Experience the Difference an OPT-In Laboratory Owner can Make

To Find the Right Dental Laboratory Partner for Your Practice

Contact Us

info@optindentallab.com

855-321-OPTN (6786)

Next month we will discuss restorative materials & more.

Proud OPT-In Members

Creating Excellence, Partnering in Growth

OPT-In Dental Laboratories...Always Aware of the Clinical Challenges You Face

Call Today and Experience the Difference

Ask for the OPT-In Laboratory Specialty You Need Most

All OPT-In Members own small Dental Laboratories

Dedicated to the successes of the dentists they serve,

The unique needs of each practice, and

Tailored to the individual needs of each patient.

About the Author

Dr. Dean Mersky practiced general dentistry 26 years in Manhattan Beach, CA before spending 7     years    as  director of clinical communication for the Captek Company. Dr Mersky has been a dental lab implant coordinator, a national speaker, authored over a dozen published articles, is a regular on DentalTown.com. He launched OPT-In Management, LLC, in 2012, to help owners of small dental laboratories better understand dentists and the many clinical and business pressures facing today's private practice clinicians.