I like to think that I have three things I provide to my dental patients:

1. Risk assessment – helping them understand and fully own risk factors for their long-term dental health
2. Risk management – helping them understand what they could do to manage that risk
3. Damage repair – definitively treating a risk that was not completely managed

Many dentists do not pay attention to occlusion unless it is a problem for the patient or unless it becomes an issue in treating the patient. As I tell dentists in Essentials 1: Aesthetic& Functional Treatment Planning, assessing functional risk is as important to me as assessing other risks, such as caries or periodontal disease. I want to find the signs of functional risk, so if a patient has higher risk of damaging teeth from excessive loading, I can help the patient understand that risk and the options for managing it.

Functional Risk Assessment

In a previous blog, Occlusal Wear Part 1: Is it advancing? How fast?, I shared the mental game I play with every patient and the ways in which I document wear changes. With every patient, I ask myself, “Is the wear I see on the teeth normal for the patient’s age? Is it advancing at a pathological rate?”

I categorize patients in one of three functional risk categories:

• Mild
• Moderate
• High

The patients I place in the high-risk category are those whose functional wear and tear is more than it should be for their age. Their teeth are breaking down noticeably faster than the average rate.

In my practice, we measure from the CEJ to the incisal edge of several teeth with wear. We take the measurement on the mid-facial and record it on the patient’s perio chart. At subsequent appointments, we can now repeat these measurements and have clear data showing that the process is continuing. Other great ways to document tooth wear are with photography and digital impressions. We compare scans months later and get a precise measurement of the change.

What causes someone to be at higher functional risk?

A lot of our patients have true TMD. What causes them to become symptomatic–where they have muscle issues, limited range of motion, jaw fatigue or joints trauma, myofascial pain, and they are breaking down their teeth? There are two primary causes: macro trauma and micro trauma.

1. Macro trauma can cause a temporary injury to the temporomandibular system that then sets up chronic problems in the joints and muscles. This could be due to a car accident or sports incident. I have a macro-trauma patient who was hit was a lacrosse stick, another that was elbowed in the jaw during a basketball game, and a cheerleader who fell off a human tower.
2. Micro trauma is what dentists call parafunction. This occurs when people put their teeth together outside the normal ways teeth touch when eating, speaking, and swallowing. We think of clenching (both static clenching and power wiggling), grinding, and tapping teeth together. We think of patients who bite their fingernails or chew on the inside of their cheeks or lips. There are lots of types of parafunctional activities. The force generated by the elevator muscles and how much of the time the muscles are overloaded leads to muscle symptoms. Accumulative force causes the excessive wear we see on teeth and damage to jaw joints.

To dentists, I say:

There are many people who have textbook malocclusions, and yet they have healthy teeth and joints. They don’t touch their teeth together outside of eating, speaking, and swallowing. There are many people with perfect occlusions who have TMD symptoms. Malocclusions don’t cause functional risk. Malocclusions don’t cause TMD. The essence of the problem is not how the teeth touch but how much they touch.

To patients with micro trauma, I say:

“You are tougher on your teeth than most of my other patients.” Staying away from psychologically negative words like clenching, grinding, and parafunction, I give them the word tougher. And I say, “You are missing more tooth structure than most people of your age.”

It is helpful for them to have this explanation before I recommend risk management strategies and pre-emptive restoration of teeth before they break.

An analogy I use with patients is the human knee. Knees don’t commonly wear out until someone is 60 to 70 years old, but long-distance runners can wear them out much earlier in life with the repetitive force of running. Our patients with parafunction put a lifetime’s worth of wear and tear on their teeth and their muscles and jaw joints in a compressed amount of time. Like a long-distance runner, their masticatory system suffers micro trauma.

It’s helpful to give patients words and analogies (like knees and car engines that wear out due to faster than normal wear and tear). I’ve had patients say to me, “I don’t like having to replace this crown, but as you said, I am tougher on my teeth than most people.”

One of the most important things I aim to do is create clear expectations for my dental patients. Over the years I have intentionally tried to shift my language from discussing “treatment” to “management” when talking with patients who have dental risk factors that will persist throughout life. Perhaps, the following short discussion will empower you to do the same.

By being intentional about this, we can:

• Reduce patient frustration,
• Avoid patients thinking we have failed them,
• Boost their confidence that we are working together to address their oral health problems, and
• Inspire them to try management therapies and return to therapies that helped in the past when there are flare-ups.

When I describe something as a treatment versus describe something as a management therapy, I inform my patients about the difference and explain why management therapy may or will never eliminate the underlying cause of their oral health issue — but by continuing to manage their issue therapeutically throughout life, they will hopefully reduce discomfort and disease.

I make a clear distinction that treatment fixes a problem, and in their case, the problem may not be fixable, although it can be managed. For example, I focus on this when the patient is truly at high risk for periodontitis. This is a patient who has suffered from bone loss and has a body that is highly reactive to the bacteria in the inflammatory disease known as periodontitis. I also focus on this when the patient has significant TMD issues.

When I tell a patient, that we are going to treat something, the use of the word “treat” sets the expectation that the problem will be eliminated. That is very different from a management strategy that helps to reduce the symptoms and/or the continued degradation of their oral health. When we tell patients we are going to do scaling and root planning and we’re going to “treat” their periodontitis, it can be really challenging for them when we recommend that they do additional periodontal therapies.

When we think about periodontal risk, functional risk, and caries risk, the reality is that risk is a bell curve. There are some people whose risk factors are easy to manage, and some people whose risk factors are very challenging to manage. We need to help patients understand that when they have certain risks, certain disorders, there really is no treatment. What we do have is a lot of therapeutic modalities that can help manage the damage, manage the symptoms. Sometimes these modalities are so effective that it appears the disorder has gone away.

We need to recognize and the patient needs to know that the disorder really has not gone away and can surface again. With clear expectations, our patients (and we) do not have to experience disappointment and frustration. Instead, we can have supportive, empathetic conversations, and move ahead with restarting therapies and trying new ones.

Many times, we need to increase the vertical dimension of occlusion (VDO) to put teeth where they should be esthetically and restore teeth that are severely worn from attrition or erosion. If you are concerned that changing VDO will cause joint or muscle pain, put your mind at rest. My experience is that it won’t. If you are concerned it will cause pain, put that thought aside too. My experience is that it won’t.

We want to change the vertical dimension only as much as we needed to accomplish the esthetic and functional goals of the case. That will minimize the effect changing VDO may have phonetics.

Phonetics May Be a Challenge

Vertical dimension has impact on two phonetic sounds in particular—F, S and V. F and V are similar. When we say them, we touch the edge of our upper central incisors just on wet-dry line on the inside of our lower lip. Saying F and V has to do with mandibular lip position, and the patient learns to adjust that position when VDO is changed. In my experience, they adjust to this in two to four weeks. They learn to accommodate a new mandibular position that touches the lower lip more gently.

S is a totally different sound. People say S in one of three different ways.

1. Some people make the sound S by making a small air space that’s between their upper and lower incisors edge to edge.
2. Some people make the sound S by making that same small air space but with their lower incisal edges just lingual to their upper incisal edges.
3. Some people make the sound S by making that same small air space but with their lower incisal edges just labial to their upper incisal edges. And those are our Class 3 occlusion patients.

The air space needs to be a precise amount of distance. If you have too little space, the patient lisps. If you have too much space, the patient spits or sprays saliva. Neither of which the patient is happy about. If the patient is totally edentulous, the patient may adapt to the new VDO of their prostheses, but patients rarely adapt to correct their pronunciation of S if they have a new VDO on natural teeth. This means we need to be careful about altering VDO.

The only way to test if a patient will have a lisp or other phonetic challenge is to test the VDO with provisionals, not with a removable bite splint.

Correcting Lisps Created by Anterior Restoration

How much air space do patients need to pronounce S without a challenge? They need about 100 microns to not lisp or spray saliva. To correct for too large or too small a space, I learned the following trick I hope you find helpful.

Madam Butterfly Silk is about 94 microns thick. I have the patient sit up and hold the silk between their upper and lower incisors with a Miller forceps. While the articulator silk is between the teeth, I have the patient count from 60 to 70. As they count the entire series of numbers, they relax into the process and red ink is transferred to their incisal edges if the space is smaller than 94 microns. If we see red marks, including on the canines, we need to increase the air space. My experience is that it takes four to six passes with the articulator silk and patient counting from 60 to 70 to adjust the airspace sufficiently. As you are doing this, the patient experiences the positive benefit of the lisp going away. I then tell the patient to go home and “observe how you sound. Ask others how you sound. We may need to do a little more refinement.”

If the patient lisps edge to edge, I shorten the lower incisal edges because upper incisors are esthetic. If the patient says S with the lower incisors lingual and they have red marks on their lower lingual and on their upper labial, I pick the upper or lower incisors and make adjustments where they are structurally and esthetically least impactful. If they are Class 3 and say S with their lower incisors, labial to their upper incisors, I always adjust the lingual marks on the lower incisors.

Dentists love the handling of self-leveling bulk-fill composites because we do not need to move the tip around, which can introduce voids, and we do not need to use a condenser to reduce voids.

A lot of science has gone in today’s bulk fill composites.

• As manufacturers have advanced the science of composites, they have had to balance the percentage of filler content and the viscosity of the material so it flows and has good handling properties.
• We now see bulk fill composites that are relatively translucent when they are non-polymerized, and when they are polymerized, they become opaquer. To increase the depth of cure, manufacturers came up with new photo initiators that require less light to activate an equal amount of polymerization.

Cap Layers

The percentage of filler content in the bulk fill composite determines whether you must do a traditional high fill cap layer. A traditional high fill, nano composite cap layer (veneer) is going to have superior physical properties, including wear resistance, esthetics, and flexural stress. When a cap layer is optional, my decision is based on whether the restoration is in a visible place, how fussy the patient is about esthetics, and if the patient is at high risk for functional wear.

A cap layer should be only 1-2 mm in thickness because our traditional high fill composites have a depth of cure of 1-2 mm. In my practice, I use a perio probe to measure the depth of the prepared cavity. When I do a class I filling, where the prep cavity does not descend beyond 4 mm, I can make the decision to fill the cavity partially with bulk fill and add a cap layer or to completely fill the cavity with a high fill bulk fill composite like SonicFill or G-aenial BULK Injectable (discussed below).

When I do a class II filling, I often place a bulk fill layer and then a cap layer. If the cavity is 6-8 mm or greater in depth, two increments of bulk fill composite can be used before adding a cap layer.

Bulk Fill Composites I Use

Personally, I prefer radiopaque materials. On radiographs, I want to easily see any voids and be able to distinguish the composite from the dentin, the enamel, and possible decay.

I’ve tried SonicFill™ by Kerr. A special handpiece injects a high filler composite while delivering sonic vibration. This composite has a higher percentage of filler content than the bulk fill “flowable” composites. The high percentage improves the physical properties of the composite, so you do not need to add a cap layer unless esthetics are important. The sonic kinetic energy temporarily lowers the viscosity of the composite so it optimally flows. This filler has a 6 mm depth of cure because it is very translucent.

Most manufacturers have a flowable composite. For these to flow, they have a lower percentage of filler content. The flowable composites self-level and have a 4 mm depth of cure. All manufacturers’ versions of flowable require a cap layer because they have lower physical properties to withstand occlusal wear.

I’ve used both Venus® Bulk Fill by Kulzer and Tetric EvoFlow® by Ivoclar in my practice. Both allow me to easily fill class I and II cavities in increments of up to 4mm. I classically use Tetric EvoFlow for my class II boxes because it is radiopaque and nicely self-levels. There are many versions of advanced bulk fill composites and veneer systems on the market, like the Tetric EvoFlow® and Tetric EvoCeram® that I use.

G-aenial™ BULK Injectable by GC is different because it has a higher percentage of filler content. This injectable bulk filler is radiopaque and can be used without a cap layer. I’ve used this in my practice to do some small class I and some class IV restorations.

There are even “condensable,” bulk fill deposits on the market with high percentage fill materials that do not require a cap layer and are highly durable. If you use these, you will have the challenge of placing more viscous materials and condensing them.

My Bulk Fill Technique

What I like to do is inject flowable material in a central position, for example, in the center of my class II box, and move the tip of the syringe as little as possible. I watch for the flow to reach the buccal, lingual, and axial walls of the cavity prep, and then I slowly lift the tip of the syringe as the occlusal is filling. I strive to not lift the tip prematurely and put it back in, because this introduces “stuck back” porosities. I do not play with the composite with an explorer or condenser because this creates “stuck back” porosities. I wait 10 full seconds to allow the composite to self-level before I begin light cure polymerization.

For years and years, we were trained to not use bulk fill composites. We were well trained to layer composites to improve the success of their longevity. For years, it was smaller layers and angled layers. What was that about? The primary issue we were trying to overcome was the shrinkage of the composite material. Shrinkage stress could destroy adhesion and fracture enamel. Another issue was depth of cure. Traditional composites couldn’t be cured in bulk. Between shrinkage and polymerization, layering became important. We would also layer to ensure we condensed the fill.

In time, scientists and manufacturers looking at this were able to alter the chemistry of the composite to alter the impact of polymerization shrinkage. When bulk fill composites first came on the market, despite what the manufacturers told me, I felt some internal resistance and it took me a while to step into the bulk fill arena. What drove me to take that leap of faith was looking into the science behind bulk fill composites.

The Science

I spoke with different scientists, from different manufacturers, and with independent scientists who created these materials. What I came to understand is that bulk fill composites are an improvement in composite technology.

The manufacturers learned how to direct shrinkage away from the bonded interface. Across the category of bulk fill materials, all these materials have a lower shrinkage stress numbers than the categories of composites that came before them. They do better at maintaining the integrity of the interfaces between the composite and dentin adhesive and the dentin adhesive and the walls of the cavity preparation.

The manufacturers increased translucency to increase the depth of cure. In general, when a manufacturer says they have a bulk fill composite, what they mean is that the depth of cure is somewhere between 4 to 6 mm. I often hear the complaint that bulk fill composites are not as esthetic as traditional composites. Each of us must answer individually for ourselves how exact and perfect we want to make the match of the composite to the surrounding tooth. Manufacturers have attempted to address this and now offer bulk fill composites that become opaquer as they cure.

Multiple Choices

Like everything else in dentistry, there are many choices. There are multiple types of bulk fill composite, even from single manufacturers, with variances in the specific depth of cure they recommend. When evaluating bulk fill composites, consider these questions:

• What is recommended depth of cure for that specific composite?
• Is the composited graded high enough to withstand occlusal loading and wear, or does the manufacturer recommend you use a different composite to create a 1 to 2 mm cap layer (typically, a more traditional nano category of composite)? The silver lining is that this provides an option when esthetics are of high concern.
• Is the composite condensable, requiring you to use condensing instruments, or is the composite more flowable and referred to as self-leveling, because it flows perfectly across to perfectly fill the preparation cavity? Self-leveling composites have a chemistry that allows them to have less initial viscosity and then thicken after they have flowed.
• Among your choices are bulk fill composites that come in small containers to go in composite guns, compules, and syringes. The less viscous, flowable composites come in a syringe that looks like a flowable and you can put a flowable tip on it.

I’ll be back with Part 2 of this blog to present more about bulk fill composites. To leap ahead, you may want to visit the Pankey YouTube channel to view the webinar I presented on this topic in 2020. You can view it here.

I had a great reminder recently while I was working with a patient that listening to patients’ intuitions and beliefs about their own dental health and care can be valuable. I’ve had this experience with many of my patients. Sometimes that value is clinical, and sometimes it is in increased patient understanding and relationship development.

I treat a lot of patients who have chronic TMD…oral facial pain…occlusal muscle disorders. You have them, too, in your dental practice. We try to help them understand that there is no “treatment,” but we have management strategies. Even when patients know this, it is frustrating for them when they have flare ups.

My patient had been comfortable and symptom free for the better part of a year, which was a long period for her. Recently, though, she had started waking up with headaches and muscle tension in her masseters and temporalis. She came in to talk about “What now?” And the answer to “What now?” is always “What has worked in the past?” We walked back on our options.

She wondered, “Can you add some material to my appliance? I always feel better at a slightly open vertical.”

The question didn’t surprise me. She’s been a dental patient for a lot of years and knows the meaning of “open vertical.” My first gut reaction was to dismiss her suggestion because it ran counter to what I know about the science and my clinical experience with other patients. I honestly didn’t want to change her appliance. But I intentionally put a pause on that resistance and sought clarification from her about what she has experienced.

Over the years, it has amazed me how knowledgeable patients are about their own dental health. They are receiving physiological data that so often they don’t know how to describe. Assessing the validity of what patients describe can be a challenge, but I’ve learned the value of acknowledging the information and asking the patient to tell me more. I ask, “Why do you think that? What have you experienced in the past that has led you to that belief?” Often, I can access the data and understand the validity of the information to help the patient.

When I don’t have a really good idea of what to do next and the TMD patient has an intuitive idea, I’ve come to respect their intuition and do what they suggest. Many, many times I have no evidence to explain why it works but their intuition works. And when it doesn’t work, it’s still okay because the patient has been validated. We’ve demonstrated we’re in a partnership in their care, and we move on to try something else.

I’ve learned to stop and recognize there must be something behind intuitions patients share. Seeking to learn more about their intuitions has led to trying new types of care and always deeper relationships with patients.

A while ago, I had the opportunity to repair a small bubble in an old composite restoration, and I got to thinking you might like to know how I use air abrasion to do this type of repair.

I don’t know how many times you see this, but I frequently see small holes in old composite restorations. In many cases, the margins look good. Everything looks good about the restoration except where there was an air bubble when the composite was placed and now there is a little hole on the occlusal surface. Food can get trapped and staining can occur in the hole, but the hole doesn’t descend into the tooth. And sometimes I see a little gap on the margin of an old composite with staining or early decay. In both cases, I don’t want to remove the entire restoration.

I use a lot of air abrasion in my practice, and in particular, I find it is wonderful for repairing old composite. I have the EtchMaster® from Groman. It’s a little handpiece that is super easy and convenient. It makes using air abrasion chairside something you will want to do every day.

Use 50-micron aluminum oxide air abrasion to clean out the stain, etch the old composite, and etch the tooth. If any tooth structure is to be etched, this air abrasion is a replacement for phosphoric acid. So, in one easy step, you have prepped the tooth and the composite. A plus of this technique is that local anesthetic is not needed if the hole does not extend into the tooth.

Now you can go in and use your dentin adhesive and replace your repair composite. Today, dentin adhesives contain MDP or PMMA which is the chemistry we need for the new composite to bond to the old composite. If I were to repair a composite restoration with a handpiece and a burr, I would not get the same bonded interface between the new resin and the old resin.

For both ease, patient comfort, and the best bond, I choose to treat previously polymerized resin with air abrasion and then some sort of resin that contains either MDP or PMMA.

Have you ever had a night guard or other full coverage dental device come back with contact only in the posterior or heavy in the posterior? It is a fairly common phenomenon. And it is a big challenge when doing two-jaw hybrid surgery and placing the temporary restorations on the day of the surgery.

I became aware of this big challenge when my oral surgeon came across the parking lot one day to discuss the upper and lower hybrid case of one of our mutual patients. This was the first hybrid case we would be doing together. He had been using a company with a software platform that does his implant planning and digital setup, and then produces his surgical guides and provisional restorations. It can even produce the final restorations. He related to me that when he tries in the initial prostheses, he always finds they are heavy in the posterior.

So, I asked him, “When they ask you for records, what do you send them?” He said they request either an upper and lower scan, or upper and lower BPS impressions, or upper and lower models. They also want a bite record and a shade. As he went down the list, something was missing that has to do with heavy posterior contacts.

Whether it is premade upper and lower provisional restorations when you are doing extractions, implants, and hybrids — or it is a nightguard you get back from the lab or Invisalign trays that you receive from Invisalign, there are occasions when we find prostheses are heavy on the posterior contacts. Sometimes there are no anterior contacts. That’s because, across the board, prostheses need to be fabricated knowing the arc of rotation, which is the distance between the hinge axis at the center of the condyle and the upper anterior teeth.

A full arch impression taken without a facebow transfer, either hand articulated or with a bite registration only over the prepared teeth, only provides the same information about maximum intercuspal position as a triple tray. If we mount the full arch impressions on a simple hinge articulator, the articulation used does not represent the arc of rotation. If we are digitizing the impressions for a digital system, we also are missing this essential piece of diagnostic information. We must have impressions mounted on an articulator with a facebow or dental-facial analyzer (DFA).

I explained this to my oral surgeon who became concerned he would not be able to deliver this information to the implant planning company he was using. But this story has a happy ending. He called the company to learn if they could use articulated models mounted with a DFA or facebow. It turns out they much prefer this! And they told him the specific articulator systems for which they have corollaries in the digital world. If he sends the models mounted on any of these, they can digitize them and know the arc of rotation.

Those who have been in my presentations have heard this many times before. The more esthetic and functional information we send to the laboratory the higher will be our ability to efficiently manage the functional and esthetic issues of the case precisely. A lesson we can learn from this story is the value of conversing with the specialists on our interdisciplinary teams and in our interdisciplinary study clubs about the importance of capturing and communicating the arc of rotation. If a laboratory is not requesting this information, have a conversation with the laboratory.

The primary purpose of Panadent’s DFA or any of the earbow/facebow systems is to capture this critical piece of information we call the arc of rotation. There is other information these systems capture but the arc of rotation is critical in establishing proper occlusion. I’ve written about Panadent’s DFA in a previous blog. For an in-person, hands-on lesson in the dento-facial analyzer, we invite you to attend our Essentials 1 Pankey course. You can also watch this video for a quick refresher.

Both periodontal disease and TMD are inflammatory disorders.

We have lots of dental patients who are suffering from the effects of inflammation, and one of the things we can do is help them look at inflammation not from just a local perspective but also from a systemic perspective. Our goal is to help them reduce inflammation where it occurs in the mouth and, also, throughout their bodies in general.

In addition to the first line dental treatments, we can work with our patients at higher risk to manage their general inflammatory response by advocating and discussing dietary changes. I have had great success with some patients by giving them nutritional guidelines.

I know some of you are “rolling your eyes” when you read this because you have had little impact on dietary changes. But we can throw it out there, and some of our patients will latch on to that information and try hard between their dental appointments to make a visible difference when we next see them. These are patients who want to be proactive, and this is something over which they can take control, much like the percentage of patients who accept fluoride varnish and implement the Sonicare devices we recommend.

We don’t need to hold ourselves out there as nutrition experts. We can explain that periodontal disease and TMD are inflammatory processes and one of the things we are learning today is that the foods we eat can increase or decrease inflammation in general. We can suggest this is something they could become curious about, do some internet research, and use the anti-inflammatory foods information they find to affect positive changes in their total health and the oral health issues we are observing.

I tell patients there are great books on anti-inflammatory diet guides and anti-inflammatory cookbooks on Amazon. Dr. Joel Fuhrman and the Forks Over Knives publications are two I mention. If you delve into reading on this topic yourself, you will find you can easily converse about the impact this reading has had on your own diet and the health of other patients.

Be as general in the information you provide or as specific as you are comfortable, but by starting this conversation with patients, you are doing your best to help them.

The question of whether it is better to have a rough or smooth tooth preparation for indirect restorations pops up from time to time, and dentists relate to me they have heard conflicting opinions.

I go to the research literature to become better informed when questions arise, and this is one question research has answered convincingly for me.

What is the impact of texture on the predictability of your restorations?

When we think about the surface texture of a tooth preparation, there are two considerations.

1. How does the surface texture have an impact on bond strength or retention of an adhesively placed restoration? Do coarser surface textures on preps increase bond strength, or is it exactly the opposite?
2. How does the surface texture impact the accuracy of a VPS or Polyether impression and therefore the fit of the restoration?

It turns out that smoother is better.

If you go to the literature and look up the research studies in PubMed, you will find there is a high correlation between high bond strength and extremely smooth surface texture. To achieve an extremely smooth surface texture, multiple studies used carbide burs that are in the same shape that we use in doing crown and veneer preparations.

The other piece of the puzzle (the second consideration) has to do with the contact angle of VPS or Polyether impression materials and the tooth preparation. The smoother the preparation surface is, the more accurate the impression will be. The more accurate the impression is, the more accurate the die will be. And the more accurate the die is, the more accurate the fit of the final restoration will be.

So, in both categories, bond strength for adhesives and accuracy of physical impressions, smoother preps win over coarser preps.