The Dentist's Network #95

The Importance of Gingival Symmetry

Most of us realize that symmetry is the core element of beauty. The most beautiful people have symmetrical facial features and bone structure that is essentially balanced. These are the people we see in magazines, movies and TV advertisements. A certain amount of symmetry must be present in order for something to be perceived as aesthetically pleasing.

This concept of symmetry is at the heart of cosmetic dentistry. Foundationally, cosmetic dentistry is all about increasing symmetry. Teeth whitening is an attempt to create symmetry and balance between the color of the teeth and the whites of the eyeballs. Teeth appear unhealthy and unattractive when the hue of the teeth does not balance with the whites of the eyes. Porcelain veneers can dramatically improve the appearance of a smile. Tooth color and texture can be optimized and the proportions of the teeth can be idealized. Additionally, veneers can mask tooth wear and minor tooth-position discrepancies. There is one particular dental discrepancy that has traditionally been a major challenge for dentists. It is also a discrepancy that, if not rectified, can prevent a smile from having the symmetry that is required for it to be a true cosmetic success. The discrepancy I’m referring to is uneven maxillary gingival heights.

Most dentists understand that ideally, we want to have the gingival zeniths of the upper central incisors at the same height as each other. The gingival heights of the upper lateral incisors should be about 1mm coronally positioned relative to the centrals. Finally, the maxillary canines should have a height that is essentially the same as the centrals. This configuration is aesthetically pleasing and the cornerstone of an attractive smile. Of course, some patients do not show their gingival margins when smiling. For these patients, the location of the gingival margins is not paramount. But patients that do not show their gingival margins upon smiling are relatively rare.

Uneven gingival margins pose a problem to most dentists because most dentists have very little control over their positions. Some enhancements can be made via periodontal surgery or tissue trimming but the amount of tissue change that can be accomplished is relatively minimal. Ultimately, these gingival margin discrepancies can be traced back to malpositioned teeth. The gingival attachment forms at a specific relationship to the CEJ of a particular tooth. Therefore, when the teeth within an arch are not level and straight, the gingival margins will almost always be in disharmony.

As mentioned earlier, porcelain veneers can improve aspects of the smile and hide some minor tooth position discrepancies, but very little can be done to balance the gingival margins when treating patients with porcelain veneers. It is not uncommon for a dentist to deftly create great veneer preparations and receive fantastic ceramic work back from their lab only to find that once cemented, the patient isn’t thrilled with the final veneer result. Oftentimes the patient can’t quite pinpoint the specific aspect of the smile that is displeasing to them. They will say things like “I’m not sure but something just doesn’t look right” or “They look nice and white but I’m just not happy with the overall appearance.” More often than not, the patient is noticing the lack of gingival symmetry and simply isn’t conscious of it. They see something that bothers them but they can’t describe what it is.

Ultimately, being a good dentist includes the ability to recognize what symmetrical discrepancies exist and also knowing how to correct them. In the words of Dr. Frank Spear, “Figure out where you want the teeth and then figure out how to get them there.” Herein lies the problem for most dentists. Most dentists don’t have the ability to move teeth other than the slight position changes that can be made with a restorative treatment plan. Furthermore, since the large majority of adult patients are unwilling to undergo traditional orthodontic treatment, a referral to an orthodontist is not accepted by most adult patients. This creates a situation where dentists are trying to provide great cosmetic dentistry for their patients but with little or no control over the all-important gingival heights.

Fortunately, many GPs have learned how to provide some orthodontic movement using clear aligners. Aligners have been a real asset for general dentists as they have provided us with a tool that can be used to address tooth-position problems. This also gives us some control over the gingival levels. However, aligners have limitations. It is quite difficult to extrude and rotate teeth with aligners and this can be quite frustrating for dentists and patients alike. Furthermore, the high lab fees associated with aligner treatment limits the number of patients who can accept treatment and also limits the payment options that dentists can provide for their patients.

The Six Month Smiles Short Term Ortho system (www.6MonthSmiles.com) has emerged as a fantastic solution for general dentists. Short Term Ortho involves the use of tooth-colored brackets and wires to level and align the teeth in an average of just six months. The orthodontic scope is more limited than that of traditional comprehensive orthodontics. The treatment goals of Short Term Ortho are very similar to those associated with aligner therapy. However, brackets and wires provide for much more controlled and efficient tooth movement. This gives us the ability to provide the needed changes in symmetry over a very reasonable amount of time. Most gingival level discrepancies can be easily corrected in just three months. This can make our cosmetic and restorative dentistry much more predictable and ultimately the end result is more aesthetically pleasing.

Most dentists want to provide great services for their patients. Cosmetic dentistry, when performed correctly, can be a life-enhancing service. A cosmetic dentist must be able to recognize and diagnose discrepancies in symmetry. Furthermore, a great cosmetic dentist also has tools at their disposal with which they can correct the problems. Gingival margin discrepancies have traditionally posed an unsolvable problem for clinicians. But, like most problems, it can be solved with ample knowledge, effective materials and a systemized approach.

Dr. Ryan Swain is a graduate of the University of Florida College of Dentistry. He practices in Rochester, NY and focuses on Short Term Ortho and other conservative cosmetic dental procedures. He is president and chief clinical instructor for Six Month Smiles. Dr. Swain is a pioneer in the field of Short Term Ortho and constantly on the forefront of GP orthodontics. He has trained dentists internationally and prides himself on de-mystifying orthodontics for GPs.

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Chris J. Lampert, DMD
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Endodontic Access Preparation

Struggling through an endodontic procedure because of a poor access preparation makes for a frustrating appointment that is more difficult than necessary. A good endodontic access cavity preparation will help make the subsequent steps of the endodontic procedure more efficient and effective. Preparing an access cavity to the proper size and shape and in the correct location is important for the following reasons.

Not Too Small
For teeth with multiple canals, the location and shape of the access cavity is important for locating canals. Undersized access cavities can lead to untreated canals because the axial walls are not extended far enough to expose the canal openings. Most notably in the molar region, an undersized access cavity hinders instrument insertion, irrigation needle penetration, obturation delivery, and vision. Undersized access cavities also prevent straight line access for rotary instruments. Straight line access is an absolute requirement for preventing rotary instrument breakage. Preserving coronal tooth structure or minimizing porcelain removal when accessing through a porcelain crown is a conservative approach, but should not be used at the expense of missing canals or providing sub-standard treatment to the underlying root canal system.

Not Too Large
Oversized access cavities can eliminate the above-mentioned problems, but they also diminish the structural integrity of the tooth and compromise the long-term prognosis. There is a fine balance between keeping the access cavity opening as small as possible, but making it as large as necessary to adequately treat the root canal system. Particular attention should be given to the 2mm of tooth structure above the osseous crest. Tooth structure in this region is very important for minimizing vertical root fractures.

Preventing Access Perforation
A common procedural misadventure to occur during endodontic treatment is access perforation. Depending on the size and location of the perforation, the tooth can be greatly compromised and may lead to extraction. Access perforations often occur because of three reasons; improper bur angulation, incorrect bur size, and deep drilling in the furcation region.

Bur Angulation
Hand piece alignment must allow the bur to be parallel to the long axis of the root structure. Misalignment can lead to a lateral perforation out the root surface. For angulated or unusually positioned teeth, I occasionally prepare the access cavity without a rubber dam to help visualize the orientation of the tooth’s long axis. The rubber dam is then placed when entry into the pulp chamber is made.

Furcation Perforations
Because of furcation anatomy, multi-rooted teeth have an added level of difficulty for access cavity preparation. The most challenging teeth to access are molars with calcified chambers or large pulp stones. These cases require deeper drilling near the furcation level to locate the canals. Furcation perforations can often be prevented by having a good parallel bitewing radiograph for determining the horizontal level of the furcation. During access, it is important to know when you are approaching this level. When I feel that I am getting close to the furcation, I remove the rubber dam and take a bitewing radiograph to confirm my location. Removing the rubber dam prevents the clamp from being superimposed over the furcation. For teeth with calcified chambers, a surgical microscope with good illumination is the best answer for preventing deep perforations.

Access Bur Selection
The number one reason for access perforation is improper bur selection. Using burs that are too large in small areas can cause big problems. A size 4 round bur is the largest bur that should ever be used for access cavity preparation. My access bur block consists of five burs, which I use to treat nearly every tooth. Occasionally, longer surgical length (25mm) burs are needed for teeth with long clinical crowns. The figure below shows the five burs in my endodontic access kit.

These five burs, from left to right, include #2 round carbide, #4 round carbide, round diamond, tapered diamond, and flat wheel diamond. I usually begin with a #4 round carbide used in a slight sweeping motion until entry into the pulp chamber is achieved. For teeth with porcelain restorations, I begin with the round diamond until access through the porcelain is achieved, then I change to the #4 round carbide. The #2 carbide is used for deeper drilling and for locating canals. When access into the chamber is complete, the tapered diamond is used for axial wall refinement and creating straight-line access into all of the canals. The wheel diamond bur is used to flatten the cusp tips to produce a flat reference point for controlling working length.

Spending time early in the endodontic procedure to create a good access cavity will make the rest of the procedure more efficient. Close attention to access cavity size, shape, and location, along with using the proper burs, will facilitate access cavity preparation and minimize iatrogenic perforations.

Chris J. Lampert, DMD maintains a fulltime Endodontic practice in Portland, Oregon, and is involved with research, testing, and development of new endodontic products. Dr. Lampert received his DMD from Oregon Health and Sciences University and his Endodontic post-graduate degree from Boston University.

Dr. Lampert can be reached at drlampert@thedentistsnetwork.net

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Louis Malcmacher
DDS MAGD
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Where Did All The Periodontists Go?

Through my weekly travels to different cities across America, I speak to many dental specialists and their groups on the hottest topics in dentistry, practice management and total facial esthetics. There are definite trends that are changing in all specialties across the board, whether it is short-term orthodontics versus long-term orthodontics, adhesive resin endodontics versus traditional gutta percha endodontics, or the conversation as to whether or not general dentists should be providing some of these specialty services.

I would have to say that the biggest change of any single dental specialty that I have seen has been in the periodontal field - there has been a real mindset change that deeply affects the profession. I am not commenting here on whether this change is good or bad, I will leave that up to the mind of the reader to decide. It is certainly something to consider as general dentists who refer patients to periodontists on what your treatment will be for the long run. I have always believed that general dentists are the quarterbacks of any patient treatment case. We certainly rely on the skills and input of dental specialists, but the ultimate responsibility should be on the general dentist.

Here is what I am being told by many periodontists who I have spoken to over the last couple of years - they would rather remove teeth and place implants than actually treat patients through traditional periodontal surgery and try having them maintain their dentition. The reason for this is really quite simple and every dentist knows it inherently. Patients refuse to take good care of their teeth, even after they have gone through the time, cost, commitment and pain of traditional periodontal surgery. This is certainly not earth-shattering news to any of you.

For years in our own practice, we have had patients who did not want periodontal surgery, and instead would rather maintain the state of their oral health with three to four month recall prophylaxis visits. We would often predict that their teeth would fall out within two to three years. Surprisingly, many of these patients have done reasonably well 20 years later, with the occasional loss of a tooth here and there. This thought was blasphemy to periodontists for years and years, but certainly it seems that conservative non-surgical periodontal recall visits and treatment have helped many patients maintain their dentition in a reasonable state so that they can function and smile with their original teeth for years.

We as general dentists know that patients, even with the best periodontal surgery treatment, often relapse and get back into their old habits and eventually their dentitions fail anyway. Not all patients, but many of them. We have learned that we have to treat people as people and sometimes you just cannot change them no matter what you do.

It seems to me that periodontists have now caught up with this concept and that is where this mindset has really changed periodontics today. Patients like the concept of implants, which are still vastly underused in North America. Many patients would rather not have to take care of their teeth and have these unsightly, mobile teeth extracted and replaced with implants, restoring their function and esthetics. It is hard to argue with a 94% implant success rate compared to the poor long-term success rate of traditional periodontal surgery. This is primarily due to the fact that we have to depend upon the patients to keep up their regimen for the long-term success of their natural dentition.

New procedures such as the Wavelength optimized Periodontal Therapy (WPT) procedure with the Powerlase AT Laser by Lares Research and LANAP procedures done with the Periolase laser by Millenium Dental have brought periodontal services into the minimally invasive realm as a solution for patients who do want to keep their teeth without heavily invasive periodontal surgery. Laser periodontal treatment will continue to develop and become even more effective in the future.

Procedures like implants and minimally invasive laser periodontal therapy will continue to improve and change the way we practice in this new decade. Is this good or bad? You are the dental clinician - this is for you, the periodontist and the patient to decide.

Louis Malcmacher DDS MAGD is a practicing general dentist and an internationally known lecturer, author, and dental consultant known for his comprehensive and entertaining style. An evaluator for Clinicians Reports, Dr. Malcmacher is a consultant to the Council on Dental Practice of the ADA.

Interested in having Dr. Malcmacher speak to your dental society or study club? Click here. To reach Dr. Malcmacher, email him at DrMalcmacher@thedentistsnetwork.net or call 1.800.952.0521.

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