Board Certified Periodontist

38 – About Dental Implants

Hi there.

You are listening to the Perio Hygienist Podcast, a podcast for my professional friends, especially dental hygienists who share with me an interest in best practices for supporting the care of patients with a history of periodontal disease and, of course and as always, anyone else who cares to listen. And if you are a student or resident, I hope this content will be useful to you as well because it is practical stuff from the outside world you are likely preparing to enter.

My name is Dr. Ben Young, and I am a periodontist actively practicing in San Antonio, Texas. The title of this podcast is: “About Dental Implants.”

And we will get to the topic of dental implants momentarily, but first allow me to orient those who may be fairly new to this podcast. You see, this podcast is an extension ofr the particular way I practice periodontics and because I really don’t know of anyone else doing it quite this way, I will assume it is a minority position.

I see myself as having two broad professional jobs. The first is I treat patients with the specialty skills and knowledge I have acquired to date. This of course is a dynamic process and involves a good bit reading, some on-line lecture meetings as well as in person courses – no different really than what everyone else is doing to keep themselves current. So that’s job one. Treat patients competently. Easier said than done at times.

The second job is a little more esoteric — meaning not as obvious or concrete as the first one – and it is to work in ways that best to support the work of others.

I see myself, even though I work independently in my own office, as but one member of a team that includes other providers as well as each patient. And it’s a team I frankly support but do not lead.  

This is counterintuitive to my dental nature frankly, because, I really like doing my own thing in my own space.  I am not a big telephone guy for example – and I think it’s something I share with most other introverts. That’s right. I’m an introvert. The way to know whether or not you are an introvert or extrovert is to ask yourself how you recharge? Do you need to be around others – or do you seek quiet spaces? I’m a quiet space sort of guy. Of course, enjoying working quietly by myself, has a strong downside in real world dental care.

Now some in our profession (more the extrovert class I think), in order to help professional colleagues, go on lecture circuits and my hat is off to them. It is a huge commitment to travel and lecture and I don’t knock how important it is because I have been a great beneficiary to many I have received instruction from over the course of my career.

But it really isn’t my thing, although I like teaching a great deal.

Instead, what I most enjoy is the day to day interactions with others focused on specific case problems. The teaching is most effective I think because there is a need to know when the problem is in our faces.

So, for me, this is where podcasting really becomes useful. It addresses the fact that none of us have unlimited time in evenings and weekends to go to lectures and courses. Podcasting is similar to listening to radio, something I can do even while exercising or driving to and from work. Another benefit of audio is that it engages the mind differently than video. – it requires a different brain activity to follow lines of discussion in my head over seeing a clever image or two. I think it is more mental work and for this reason I think the payoff is greater.

Certainly, both are beneficial, and they really aren’t mutually exclusive. For me, however, audio is my main information source. Also, the production of audio for me is more practical, fits better with all I do in my Job One, over video production – which is much more time consuming.

So, bottom line. I see podcasting as part of my professional work life – not an different job – and its purpose is to in team communication – to keep connected with others, especially those where we are treating the same patient. Think of how remarkable it is for a patient to return from having been treated by me and to have a conversation that sounds strangely in line with the concepts they have just heard from me and others in my office. When messages are repeated, it aids in deepening the patient’s ability to learn – and learning is usually just the process of hearing things frequently enough so it goes deeper in us and so is more difficult to forget. On the other hand, when different messages come from different authorities, then often it negates the important messages patients need to have confidence in in order to achieve and maintain health.

And that’s why I don’t work too hard at always trying to be original. I want you to hear echoes of previous podcasts because I hope it reinforces important concepts.

Recently, a patient came to me referred by an excellent comprehensive dentist friend to evaluate a problem with a loose crown/abutment over a dental implant. The implant was placed 7-10 years ago by another dentist entirely.

According to the patient, about two years ago or so, the crown became loose. This crown is the replacement for a lower first molar and he is missing the two molars behind this one.

Now in my last Perio Patient Podcast, Episode 68, a podcast for my patients, I talk about this same story, but there I go a little more into the history of implantology. With you, we can skip to the chase.

Problems with dental implants break into three areas.

The first one has to do with the bone/implant interface and the failure to achieve osseointegration.

The second has to do with excessive occlusal load.

And the third area where problems with implants come from is along the line of periodontitis – and we call it periimplantitis.

So, let’s briefly think about each of these potential problems.

If a dental implant has problems, say, within the first six months or so, it is likely due to a bone/implant connection failure. Adequate osseointegration was not achieved. The body’s bone cells did not grow and adhere to the specially designed implant surface, at least in enough quantity to cause the implant to become, what they normally become – ten times stronger or more capable of handling loads in the axial direction compared with natural teeth.

These problems can be significantly reduced by not pushing the healing envelope after the implant is surgically placed. In other words, sometimes it is acceptable, even smart to extract a tooth and place an implant immediately. At other times it is better to stage things so the implant rests within the bone and heals before stage 2 – the uncovering of the top of the implant and the process of placing the abutment and crown, which then begins the implants functional life of taking on chewing forces

When I place a dental implant, especially where a tooth has recently been removed and the socket grafted, I want to see that most of the implant surface will be touching the patient’s native bone and not graft material. I want to give the body enough time to convert particulate bone or spaces filled with the patient’s blood products to bone attaching to the implant.

After the implant has healed past six months and there are no signs of problems, then most likely any problems that then occur have come after successful osseointegration has been achieved. Now the greater concern has to do with loading resulting in microfracture of the interface between the bone and the implant. Cyclicle excessive loading in the problem. This is why it is important to check occlusal contacts with articulating paper and shimstock annually.

To explain to patients the difference between how dental implants take forces and how teeth take forces, I start by first reviewing the four parts of the tooth.

So here’s an obvious echo from the past. The four parts of a tooth are: enamel, dentin, pulp and the least known, but most important when it comes to periodontal disease – cementum and the little fibers that project from it are called periodontal fibers. These act as sort of the shock absorbers for the tooth. When a tooth is overloaded it compresses these fibers – which does two things. First it allows the tooth to move and in moving absorb some of the force of the load. If this is exceeded then the tooth breaks. Teeth can get loose and then tighten up again thanks to the activities going on with the periodontal fibers – also called ligaments. The principles of moving teeth with orthodontics involve this process as well. The second way these fibers help when teeth are overloaded is due to the nerves that fire and send a message to the brain with not only the pain information but also the location of the problem. This ability to tell the brain locations of where the different parts of the body are relative to one another is called proprioception. This is what gives you the ability to touch the first fingers of your two hands together even while blindfolded. Proprioception allows you to floss teeth you can’t see and to eat food without biting your tongue and cheek at the same time.

But what about dental implants? First, they do not have a fiber system surrounding them. They are fused directly to bone. This means they do not have the same proprioceptive ability. Because they osseointegrate directly to bone they resist forces better than teeth. However, if the forces reach a destructive level, and the brain is not aware this is happening, then eventually there can be microfracture of the implant/bone interface. If this happens then the implant will become loose and eventually fall out. It will never tighten back up. Another possibility with excessive forces is fatigue of the metal which then results in a fracture or fractures within the implant. This is actually a good thing in that dental implants are engineered for the replacement parts of the system to fail before the implant fixture does.

Unfortunately, for the patient who came to me with a loose crown/abutment that has been present and annoying him for the past two years, it was the implant itself that failed. Once the crown/abutment was removed I was able to see that the implant walls had fractured. We call this flowering. This is not repairable and so required the removal of the implant body followed once again with bone grafting to repair the defect and prepare this site for another dental implant down the road. This implant site will first be studied by CBCT and when ready for the next implant, it will be placed utilizing a 3D printed surgical guide for pilot drill. I find this approach gives me the best of both words. I use the pilot drill to provide the depth and trajectory of the implant and I develop the osteotomy site visually – not through soft tissue. I want to see the top of the implant’s relationship to the bone crest and then I want to close the soft tissue over the implant in order to optimize healing.

And now for a moment let’s talk about the third way implants can fail. Chronic infection/inflammation. Some believe this is the greatest cause for failure of the three. Just like periodontal disease, infections can occur around dental implants. These begin as bleeding and bone can be lost as pockets around implants deepen.

Some are afraid to probe around implants. Don’t be. Use plastic probes if you wish. I just use my standard UNC probe because remember, we are probing the pocket where the surface is already exposed. I don’t think probing this gently is a great source of damage and will be the reason a dental implant fails. If you meet resistance when you probe – don’t press further so you do not harm the soft tissue attachment to the implant. Also, understand that you are often probing to the top of the bone. In other words there may not be a two millimeter distance from the base of the pocket to the top of the bone as it is with teeth. This is more variable. For this reason, it is not unusual to find probing depths that are 4 and 5 mm in depth that are stable and healthy. Obviously the greater the depth the greater the possibility that organisms can colonize. Take bleeding around implants seriously and this is a good reason to refer back to the periodontist to take a look as well. The only point I want to make here is to not ignore the dental implant and to be critical of what you find. The sooner we can manage increased levels of inflammation around the implants the better the long-term outlook for the implant and the patient’s overall health.

So quick review. It is critical that patients understand that dental implants should be checked annually. Every year it is a good idea to take a dental x-ray to make sure the bone levels are good and that there is no evidence that something has become loose. Also, bite forces need to be checked with articulating paper and shimstock over dental implant crowns. Ideally initial contact forces when the patient bites down are between teeth first. Once all the teeth are contacting, then the implant crown should contact. The shimstock helps show which contacts are hitting first. Another way to think of this is to understand that the thickness of the shimstock represents the thickness of the periodontal ligament space.

Finally, remind patients that if something feels loose, they should not wait to see if it gets better. It won’t get better and perhaps if they are seen soon enough the implant fixture will still be useable.  

Well, that’s enough to chew on for now. This has been The Hygienist Podcast and I am still Dr. Ben Young. Thanks for listening. If you have questions or comments, please let me know.