Ask Dr. Christensen

In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers.

by Gordon J. Christensen, DDS, MSD, PhD

In this monthly feature, Dr. Gordon Christensen addresses the most frequently asked questions from Dental Economics® readers. If you would like to submit a question to Dr. Christensen, please send an e-mail to info@pccdental.com.

Question...

I am convinced occlusal splints are a viable treatment for many oral and facial conditions; however, there are many different types of splints available, and each type is represented as the best. Which type of occlusal splint is the best or are they all similar in their potential for treatment success?

Answer from Dr. Christensen...

Occlusal splints are similar, but not identical, in their ability to help patients with their occlusal challenges. My conclusion is based on my many years of experience, but you will find that some readers disagree with my opinions.

The most commonly used and accepted type of splint for all occlusal pathologic conditions is the full-arch splint, with at least one occlusal contact on each tooth of the opposing arch. Although it is controversial, I prefer maxillary splints when I use a full-arch splint. I do so for the following reasons:

Most of a typical occlusal equilibration is accomplished on the maxillary arch. When treating a temporomandibular joint dysfunction (TMD), most practitioners initially use an occlusal splint for a few weeks of splint therapy, followed by an occlusal equilibration. Subsequently, the splint is used only at night and during psychologically stressful times. After occlusal equilibration, the maxillary splint can be placed back into the mouth without significant change. However, a mandibular splint must be changed significantly for use after the occlusal equilibration, because the maxillary teeth have been altered. Additionally, maxillary splints can be stronger than mandibular splints because some of the palate can be used as support.

Although most full-arch splints are hard resin throughout, some labs process soft material inside of a hard splint shell to facilitate splint-seating. As a result, splint longevity is reduced because the soft material degenerates over time.

Partial occlusal coverage splints have become popular for TMD, bruxism, clenching, and other conditions. They are simple to make, easily understood, and easy to maintain. The most popular partial occlusal coverage splint is the NTI-TSS, telephone (877) 550-2992. Another similar partial coverage splint is the Best Bite, telephone (888) 865-7335. As long as these splints are worn only part of each 24-hour period - usually during sleeping -­ they are remarkably successful. These splints are effective because they eliminate all posterior tooth contact and prevent temporalis muscle function. This reduces intense muscle activity and aggressive tooth contact. Totally soft splints are effective for a brief period of time, but they wear out rapidly, and can cause undesirable tooth-drifting and occlusal change. Find out what type of splint your lab can make at a reasonable cost, and institute splint therapy into your practice.

We have three new videos on occlusion that will answer the most frequently asked questions on this subject. They are V3104, “Occlusal Splints - Predictable, Frequent Use;” V3106, “Simple TMD Therapy for Your Practice;” and V3105, “Uncomplicated Occlusal Equilibration.” For more information, contact Practical Clinical Courses at (800) 223-6569, or visit our Web site at www.pccdental.com.

Question...

Resin cementation of indirect tooth-colored inlays, onlays, crowns, and fixed prostheses has posed a major problem for me. Either I use a typical light-cured bonding agent and cure it at the same time as the cement - wondering if the light reached it - or I use a total-etch or self-etching primer before the cementation ... and wonder if I will still have some postoperative tooth sensitivity. What is state-of-the-art for resin cementation of these restorations?

Answer from Dr. Christensen...

You have undoubtedly heard of the combination self-etch resin cements. In recent months, this category of resin cement has had a remarkable impact on the profession, and I have yet to find anyone who has experienced postoperative tooth sensitivity using this concept. Led by the introduction of RelyX Unicem from 3M ESPE, followed by MaxCem from Kerr, and Embrace WetBond from Pulpdent, these cements have ease of use, great strength, no solubility, and, most importantly, no postoperative tooth sensitivity. Time will tell which is the best brand, but all of them have reported great success from initial field studies.

All three brands have minimal colors, and they could possess more translucence, so a market void is still present in the area of a multiple-color, self-etching resin cement for veneers and anterior, translucent all-ceramic crowns.

For tooth-colored inlays, onlays, crowns, and fixed prostheses, I suggest self-etching resin cements. I still use resin-modified glass ionomer for routine cementation of day-to-day PFM restorations. Also, in the event that the patient has high caries activity and the tooth-colored ceramic restoration is strong - such as the zirconia-based materials - I prefer resin-modified glass ionomer to provide fluoride release and potential cariostatic activity.

Our new video, V1502, “The New Generation of Tooth-Colored Inlays and Onlays,” will answer many of your questions on this subject. For more information, contact Practical Clinical Courses at (800) 223-6569, or visit our Web site at www.pccdental.com.

Dr. Christensen is a practicing prosthodontist in Provo, Utah. He is the founder and director of Practical Clinical Courses, an international continuing-education organization for dental professionals initiated in 1981. Dr. Christensen is a co-founder (with his wife, Rella) and senior consultant of Clinical Research Associates which, since 1976, has conducted research in all areas of dentistry and publishes its findings to the dental profession in the well-known “CRA Newsletter.” He is an adjunct professor at Brigham Young University and the University of Utah. Dr. Christensen has educational videos and hands-on courses on the above topics available through Practical Clinical Courses. Call (800) 223-6569 or (801) 226-6569.

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