Bite Point

Microscope Dentistry: So Smooth, So Crisp

Two years ago now, I started using this little fella:

This is a Global Surgical Specialties Dental Operating Microscope. It cost as much as my Prius, but every penny was worth it, because Microscope  Dentistry is the biggest game-changer that I've ever experienced in my profession.

In those two years I've naturally been to a number of continuing education courses. The speakers often use PowerPoint to project images of treatments they've done on immense screens. Any and all imperfections show up huge! I know, I've tried it with my own shots. And yet, the artificial restorations that we can create in dentistry often look remarkably like the nearby natural teeth that they're meant to seamlessly blend in with. Dental materials, porcelains in particular, can be made to match not only color but translucency, opacity, saturation and surface texture. The treatments we can provide today are beautiful, even blown up to the size of a tennis court.

Usually, though, their preps look all ratty.

Uneven margins, that critical edge to a dental preparation where the porcelain meets the gums. Nicks on the walls that make it hard for the lab technician to make a well-fitting crown. Tissue tags that lie over parts of the tooth like unwanted crabgrass on a lawn, interfering with the taking of an accurate impression.

These things simply don't happen in the world of Microscope Dentistry.

Here is a combined impression of a dental implant and a natural tooth, both for crowns. That natural tooth is a second molar; typically, there's an awful lot of trauma to the gums at the back (distal) as the highly convex contour is whittled away to gain a proper shape. Here, we hardly even see any blood. And the margin is smooth, crisp and even.

The implant tissue is also visualized extremely well, and it's beautifully healthy. This is always the case when Tom Kohler DDS, our main periodontist referral, has placed the implant.

And here's the impression. Without a spectacularly accurate impression, there will never be a spectacularly accurate dental restoration:

Jucundo et Solvere

Jucundo et Solvere

(1) Delight people.

(2) Solve their (interesting) problems.

All the rest is commentary.

(This is how to achieve success in the realm of the bespoke business, though not in the realm of the commodity.)

 

 

Mouth Guards: Seat Belts for Teeth! -Neha Shah DMD

Please welcome once again my friend and remarkable endodontist Neha Shah, D.M.D., as she informs us about dental trauma and its prevention. (She is my favorite kind of doctor, in any field of medicine or dentistry--the kind of doctor who excels at treatment, and then goes on out and helps people prevent that very treatment that she does so well!)

*****

Seat Belts for Teeth!

As we approach the warmer seasons of spring and summer, there is a generalized increase in outside activity. Though leading an active life is extremely important, safety should be paramount.

Recreational activity may increase for the general public, however children play competitively for their school throughout the year. When they play sports for their school, the school takes on the responsibility of ensuring the student athletes’ safety. They supply them with or provide them with list of gears that are necessary for their protection. However, one of the most neglected safety gears is the mouth guard. Even though it is recommended, athletes rarely wear it especially in sports like baseball, basketball or soccer. Just as a helmet, chest vest, kneepads, and shin guards serve to protect different parts of the body; mouth guards serve to protect the teeth against impact injuries.

Dental trauma is nondiscriminatory; nonetheless, the most active kids and adults are the most susceptible. Up until we are 6- 7 years old, any injuries to teeth that occur would be to primary or “baby” teeth. And though this can be traumatizing, it is less likely to have permanent or long-term consequences. However, as the adult, permanent teeth start to form, erupt and replace our “baby” teeth, protection from trauma becomes imperative. Damage to these permanent teeth can be devastating, irreversible or permanent. The most common teeth that are prone to sport or fall injuries are our front teeth. Teeth can fracture, shift from its original position in the jaw or can completely be knocked out of the mouth. The severity, lengths of time from injury to treatment and the type of treatment rendered all have a significant impact on the outcome and long-term consequences.

Mouth guards are like seat belts. Just as seat belts help to restrain and protect the driver during an accident, mouth guards help to protect the teeth from impact and to keep the teeth in position in case of an injury. Athletic directors and coaches across schools should encourage and insist on use of mouth guards for all their student athletes.

When impact injuries to teeth do occur, it is important to see your dentist right away. Time is of the essence. The longer the tooth remains in the altered, injured state, the more likely it will have irreversible damage. This is analogous to a fractured finger, for instance. When one suspects a fractured finger, the best time for treatment is immediately. We know that the sooner the finger is splinted, the better the outcome and the faster the recovery. The concept is the same for teeth. Teeth that have sustained traumatic injury, like a dislodged tooth, will need to be splinted and require root canal therapy. The dentist may refer one to an endodontist. Endodontists are dentists who are specialist and have the knowledge and the special skills to diagnose and treat teeth with acute traumatic injuries or teeth that have had past history of traumatic injury. Endodontists, who are root canal specialists, can properly diagnose, monitor and conservatively treat teeth with traumatic injuries.

So next time, wear your mouth guard and when you are up at bat, knock one out of the park, not your mouth!  But if you do, go to the dentist immediately!

*****

Dr. Shah's office information is:

Neha Shah, D.M.D.
Atlantic Endodontics
235 E. Jimmie Leeds Rd
Galloway, NJ 08205

(609) 568-6415

 

Articulating Paper- Isn't there an App for this yet?

Anyone who has ever had any sort of dental restoration has heard those charming words: "Bite and grind, please!" as we check whether our crown or filling is properly hitting the opposing teeth. Occlusion, we call this. How our teeth meet each other across the arch. Which in all except the most catastrophic cases of crowding and misalignment, is far better than how the Rs and Ds meet across that fabled aisle in the Capitol Building...

When we exhort our patients to close their jaws and check a restoration, we slip marking paper between their teeth and get marks that show the pressure points between opposing teeth. It's like a language to me at this point; second nature. I can tell when my restoration is too high and adjust it down till it's just right, yet not overshooting until it's out of contact entirely. Do that, and teeth will shift unpredictably until they hit once again as we bite. It's a classic case of more is not necessarily better.

Now, before going on, I must say that this phrase "bite and grind" is problematic. It's a Freudian slip waiting to happen, is what it is.

Once, years ago, a patient came to our practice who plied the trade of exotic dancer. And yes, it happened, dang it! All morning I had steeled myself against the inevitable, but then, the inevitable happened anyway.

"Bump and grind, please."

Arrrgh! I was so embarassed. I'm a rather Victorian sort of chap at heart, in some ways. And how is one to recover from such a gaffe?

Anyway- to the marks. Big, heavy marks indicate high pressure points between the teeth. Marks that look like rings- marking material in a circle, with no material in the middle- "doughnuts"- indicate even higher pressure points!

We dentists pay great attention to the absence of marks, as well. No mark where there should be a mark is often a rather bad thing, and corrections must be made to bring all the proper marks back.

Always reminds me somehow of Sherlock Holmes and that dog:
"Is there any point to which you would wish to draw my attention?"
"To the curious incident of the dog in the night-time."
"The dog did nothing in the night-time."
"That was the curious incident," remarked Sherlock Holmes.

Here's the curious thing about articulating paper marks- sometimes, very small marks indicate the highest pressure of all!

Have a look at this photo:

Those two marks on the last tooth in back are fairly small. Yet there was pain, including muscular pain. What was happening is that the patient's teeth had gotten out of alignment. Whenever she closed to chew, she could get her teeth together, but first they had to rock over this last pressure point. Muscles and teeth got sore!

I adjusted her bite and here's what we got:

All the marks are better, but the ones at the white arrows weren't even there before! And there are doughnuts. Comfort ensues. And the black arrow points to the reduction in pressure that made all the difference.

Maybe someday there will be an app for digitally reading bite pressure between teeth. Until then, the next time your dentist has you bite and grind on that funny paper on a stick, remember that she is reading a very specialized language indeed.

There is no "Get."

Very often, we receive ads like this in the mail and email:

I object.

My goal is not to "get" new patients. 

My goal is to meet someone new and make a difference for them. Maintain health. Solve a problem. Many dental problems are physically painful, or esthetically painful. I hope to solve such a problem for you.

But "get?" There is no "get"...

With your permission--your valuable, almost sacred permission--I will strive to delight you, solve your oral health problems, and help you maintain your health once attained.

What goal should a business have? The relentless pursuit of More, or the gracious pursuit of Making a Difference?

Bridges, Ridges and Endodontic Treatments

This radiograph shows a dark area (circled in red) at the tip of the root of the tooth on the right. This is a sign of root canal infection. We treat people, not X-rays, so we always perform a clinical exam and ask for the history of present illness. This tooth was painful and there were other signs of infection as well, so it needed treatment. Actually, this tooth was about as heavily restored as it could be and still support the bridge--the three-tooth structure of artificial crowns that is built upon it.

 

This next shot, post-treatment, shows so many interesting things.

The dark blue arrow shows the main body of the root canal filling, and the light blue arrow shows the post (a rather aggressive one, I admit) that was placed into this tooth to help hold the overlying bridge to it.

The black arrow points to a wonderful 3-D fill of the tip of the root canal system with Resilon, the advanced endodontic filling material. Many times, the tip, or apex, of a tooth is like a river delta--but in 3 dimensions! There is also a cement puff beyond the tip of the root. The body will dissolve this in time. It indicates a very thorough sealing of the canal system when it happens.

The red arrows point to that circular dark area, the sign of infection. In time this will return to the appearance of normal bone.

The green curve marks the lower floor of the maxillary sinus. In every X-ray we take, we are reminded of the incredible density of vital anatomic structures in the head and neck, and how close we come to them in our treatments.

The other tooth, the molar to the left, has a root canal treatment as well. The thin straight line next to it is just an artifact on the phosphor plate that reads the image.

Finally, here's a clinical image, with the bridge off:

The arrow points to the collapse, or resorption, of bone that commonly occurs after extractions. This is due to the thin nature of the buccal plate, or bone to the direct outside of out teeth. This collapse can be prevented with bone grafts at the time of extraction, something that is highly desireable if implants rather than bridges are planned.

More on these topics here:

http://rickwilsondmd.typepad.com/rick_wilson_dmds_blog/2010/08/bundle-bone-and-dental-recession.html

http://rickwilsondmd.typepad.com/rick_wilson_dmds_blog/2012/04/bone-grafts-in-dentistry-the-bone-sets-the-tone.html

 

 

Pontics in Implant Dentistry

In a world where money was no object, and where concerns over bone volume and nerves and sinuses didn't encroach on our plans for placing dental implants, we would always have one implant per tooth in our restorations.

That's not the world we live in though, is it?

My patient of many years experienced slow failure of a lower bridge. This scenario has its positive side. If you know the loss of multiple teeth is inevitable, but not immediate, you can plan for the treatment. From a financial standpoint, this is a splendid advantage. (You just do the exact opposite of the U.S. Congress. You anticipate a significant expense in a few years, so you budget and save for it. They anticipate a significant expense in a few years, so they spend more than they take in the whole way along. And yes I mean both parties).

Now, in this case, there was a bridge on natural teeth. There was long-standing bone loss (height and volume) where the teeth were missing, and over the years more bone loss occurred around the remaining supporting teeth. Thus, when our oral surgeon referral evaluated this case, he had to gain significant bone with grafting materials and also was forced to avoid the inferior alveolar nerve as it coursed through the jaw and leaves through the mental foramen.

This image from http://www.ejomr.org/JOMR/archives/2010/1/e3/e3ht.htm gives us a view of the nerve/vascular canal which must be avoided in implant surgery. (The article explains these surgical issues in great detail).

Once bone grafting was performed and healing was complete in our patient, it was time to assess implant positions. A surgical guide was made that gave a 3-D representation of where the teeth would ideally go. After all, we're not going to all the trouble to place implants just for fun--the goal is beautiful, functional teeth. This planning process showed that there was no way an implant could go in the most forward position. That's tooth #28, the first premolar just behind the canine, for you cognoscenti in the audience.

Also, definitions. A bridge is multiple artificial teeth linked together, whether on natural teeth or implants. An abutment is an artificial crown, as part of a bridge, that is directly placed on a natural tooth or implant. A pontic is an artificial crown, as part of a bridge, that spans an intentional gap where there is no tooth or implant.

Thus, we decided to place three implants and four teeth. Three abutments and one pontic, making four total. Each implant would go where there was adequate bone quality and quantity, and we would avoid damaging the inferior alveolar nerve by traumatizing it during surgery.

Here is our result, landing on the lab's working model. The plastic that mimics the contours of the gums has been removed for a clear view of the implants.

Three implants, four teeth!

Dental implants are so strong at this point that this sort of ratio--four teeth to three implants--is absolutely fine. Plus, the jaw curves, so there's always better resistance to the lateral forces of chewing than if three implants were in a perfectly straight line.

There are limits and we have to be careful. Placing, say, five teeth on two implants is not a supportable idea, and really bad things start to happen if we overload such complex systems. Porcelain fractures, repeated screw loosening, and even failure of the implants themselves can result.

And yet four dental implants can support an entire denture-like prosthesis, one that doesn't come out (unless the dentist intentionally removes it for cleaning or repair).

Here's an All-On-Four schematic from Nobel Biocare:

That's because dentures have large stress-absorbing frames and four widely spaced implants to support them. Think of barstools. Most are made with four legs. Patrons of pubs would be challenged by, but could probably make do with, a three-legged barstool. Yet no one would suggest making these things with just two legs, and, well, a uni-stool is just completely out of the question.