Treating the Avulsed Permanent Central with Fully Formed Root

You're listening to the Phil Klein Dental Podcast from Viva Learning.com. So a few months ago, my 12-year-old cat decided to make an Olympic jump from a small table in our kitchen to the countertop. And I think he imagines himself as a young fit athlete and is oblivious to the fact that he is in fact a senior cat. So when his 12-year-old body landed, one of his legs gave way and his face met head-on with the surface of the granite. Overall, he was fine, thank goodness. just a little shook up. But the incident resulted in his lower right canine being knocked out of his mouth. Poor Simba had his first avulsed tooth. So that night when I was thinking about what happened to my cat, I also realized that of almost 650 episodes of this show, we don't have a single episode on tooth avulsion. I don't even think we have any content about tooth avulsion at all. Maybe not even in our webinar series as well. So I tried to find a few dentists to interview because that's the format of the show. I'm the one that asks the questions and the KOL, the key opinion leader, is the one that answers them. But that didn't seem to materialize. There was some date conflicts and whatever. I had trouble finding a dentist that felt confident enough to talk about this topic. So as an endodontist myself, I decided, you know what, I'm going to cover this. So I did some research to make sure I was up on everything. So here we go, our first episode on tooth avulsion. So picture this, you're in your operatory in the middle of a restorative case on a Thursday afternoon, and your staff member comes in and says, your 10-year-old patient, Johnny Smith, just fell off his scooter and knocked out his upper right central incisor. The mother's pretty stressed out, as you can imagine, and she's waiting for you to come to the phone. So the question is, as a GP, are you prepared to handle this case in the best possible way? Now, in this episode, we'll review the basics on how to handle the avulsed permanent tooth. And specifically, we're only going to be talking about a permanent tooth with complete apex formation. So in a future podcast, we'll talk about avulsion of permanent teeth that have incomplete apex formation because that's a different treatment protocol. So we're going to be focused on the permanent tooth that's been erupted for three years or more. We'll be right back in a moment, but first, for the optimal bond between zirconia and your resin cement, check out Bisco's Z-Prime Plus. Rated best in class by thousands of top clinicians, Z-Prime Plus, featuring MDP, creates a strong, reliable bond to zirconia, metal, and alumina substrates. And nothing could be simpler. It comes in a single bottle, and it's 100% compatible with both light-cured and dual-cured resin looting cements. It's time you get the most out of your zirconia restorations. To learn more about Z Prime Plus and the entire Bisco Adhesive product line, visit bisco.com. So to begin, I just want to address some important facts or give you a background about traumatic dental injuries in general. Traumatic dental injuries are fairly common among children between the ages of 8 and 15 years old. In fact, studies have shown between 6 and 34% of children in this group in this age group, experience some form of dental injury. Now, as expected, boys experience dental injuries at a rate that's at least twice as often as girls. And tooth avulsion accounts for up to 3% of dental alveolar trauma to permanent teeth, and most often involves upper anterior central incisors. So there are also a number of risk factors that we should know about, and they're associated with the incidence of dental trauma. These risk factors are reflected in the lifestyle of the child. So if a kid plays ice hockey, skateboards, and is on his or her scooter all day, that child is certainly at a greater risk of a traumatic dental injury than a child who spends their free time playing the clarinet, building model airplanes, or playing chess most of the day. So we get the idea. There's also physical characteristics that increase the risk of traumatic dental injuries. And examples of those include overjet, increased overjet. Obviously, the teeth are more exposed to getting a traumatic injury, and children that exhibit incomplete lip closure. Same concept. So, after a tooth avulsion occurs, the goal is to get the avulsed tooth back into the socket as quickly as possible. That's the idea, preferably within 30 minutes. Now, worst case, 60 minutes. You'll often hear about dry time and storage time. Now, dry time refers to the time the tooth is out of the mouth, and not in any kind of storage medium. Storage time is the time the tooth is submerged in either what we call Hank's solution, which we'll talk about more shortly, milk, saline, or even under the tongue in saliva. And that storage is being used while the tooth is being transported to the dental office. So the key thing is dry time, because if that exceeds 30 minutes, the chance of future resorption of the root is high. So keep in mind, the tooth can be in storage for up to six hours and still survive for years in the mouth without resorbing. It could be stored for six hours, especially if it's in something called Hank's Solution, which we talked about earlier, which is the full name is Hank's Balanced Salt Solution. That's the ideal medium to put a tooth in when taking it to the dental office for replantation. So as I mentioned, that could be up to six hours. the tooth is knocked out and within three minutes it's put into that solution. That means the dry time is very, very low and the storage time is quite high. You want a short storage time too, but if it goes longer, it's not the end of the world unless you surpass six hours of storage time. So research has shown that the ligaments surrounding replanted teeth that were out of the socket for less than 30 minutes have a fairly decent chance of repairing themselves. Having said that, the permanent tooth with full root formation, which is the subject of this episode, will still need to have root canal therapy. We should not expect any revascularization through the apex of a mature tooth after its replantation. That ain't going to happen. And we're talking about an apical foramen of one millimeter or less. But nevertheless, if we can get the PDL to repair itself, the replanted tooth could, with proper endodontic restorative care, in a large percentage of cases, last as long as any other tooth in the patient's mouth. And that's our goal. Now, if the ligaments experience too much damage, either by physical damage or if the cells are dry for too long, more than 30 minutes, the resulting process after replantation is often bony replacement. Now, when I say physical damage, that means that the tooth was scrubbed, it may have been handled by the adult, that's holding the tooth, they're holding it by the root, and they're twisting the tooth with their fingers or trying to clean the debris off with their fingernail, and they've basically imposed physical damage to the PDL. Even if the tooth is dry for less than 30 minutes, if physical damage is substantial, the prognosis is not good, and we're looking at a good chance of bony replacement. So over a number of years, in those cases, the adjacent bony socket will remodel the tooth, essentially replacing the root with bone, leaving the tooth with no root. And of course, once the root is replaced, the visible part of the tooth, the crown will eventually give way and be lost. Stay with us. We'll be right back in a minute. We all know that to achieve healthy, beautiful smiles, we sometimes need to align the teeth. and to do so, aligner therapy is a great option. So why not set your practice apart with 3M Clarity Aligners Flex from Solventum, formerly 3M Healthcare. Designed for comfort, Clarity Aligners Flex feature a thin, flexible design. yet they deliver excellent force persistence over a two-week period. Plus, they resist scratching and stains, and they're backed by a dedicated clinician team providing support every step of the way. With a variety of affordable case-type options, single or dual arch, Clarity Aligners Flex offer a great value to your patients and practice. To learn more, visit 3m.com slash clarity dash aligners dash flex. So let's get back to that phone call with Johnny Smith's mother. Again, Johnny is 10 years old, so we have to assume the apex of the root is fully formed. So on that call, the first thing we need to find out is whether or not Johnny has any other injuries related to the trauma. Does he have a severe headache, blurry vision, or is he showing any signs of a neurological injury? Of course, that's way more serious than an avulsed tooth. So if that's the case, Johnny needs to go to the emergency room immediately of a hospital. Now, if at all possible, if the adult can take the tooth and put it in a container of milk during this time or Hank's balanced salt solution, if it's available, which could be available if it happened at a school or gymnasium where they have a first aid kit or first aid supplies, that would be ideal to get that tooth in a storage medium that's acceptable because there's likely somebody that's on staff in the hospital that's trained on putting the tooth back into the socket. So on the flip side, when you ascertain that there's nothing else wrong with Johnny, other than the fact that he had his tooth knocked out, you can continue to instruct Mrs. Smith on what to do next. So here are some questions you can ask. Mrs. Smith, do you have the tooth? Yes. Do you feel comfortable putting it back into the socket? I think so. Okay, hold the tooth by the crown, that's the enamel of the tooth, and gently rinse off any debris using milk. Or if you have a saline solution, you can use that. Be sure, Mrs. Smith, not to scrub it or use your fingers on the root of the tooth or your fingernail. Don't use any soap. And always hold the tooth by the crown of the tooth, the enamel of the tooth. Now, after rinsing it off, carefully place the tooth back into the socket. If you're not sure, Mrs. Smith, how the tooth should be oriented, look at the tooth right next to the socket and use that as your guide. Once you seat it back into the socket, have Johnny gently bite on a napkin to keep it in place, and then head over to my office as soon as possible. Again, if we can get the tooth replanted at the site of the trauma, we're dramatically reducing dry time, which is the time the PDL is exposed to air. This means we're likely to preserve the PDL cells and less likely to have bony resorption or ankylosis. Now, in most cases, the adult who is with the child will say they're not comfortable replanting the tooth. So in this case, here's what you can ask Mrs. Smith. Are you in a school or facility that has a nurse or emergency room? Because if you are, they may have a container called Hank's Balance Salt Solution. Her answer is no. I'm outside at the park. Okay. Can you get a container of milk? Yes. There's a 7-Eleven right here. Great. Go to the 7-Eleven, buy a container of milk, and drop the tooth inside it. Once you do that, come directly to my office. Okay, I can do that. I'll be there in about 10 or 15 minutes. So that's the conversation that you would have with an adult. One scenario, they were able to put the tooth in themselves. The other one, they dropped it into a storage container. So now let's talk about what happens when Johnny arrives at your office. Let's talk about the first scenario where the tooth has been replanted into the socket. The first thing you want to do... is to get a good medical history and rule out any neurologic and non-dental injuries. You want to also rule out alveolar fracture. A good idea would be to take three radiographs, angulated differently to rule out root fractures. Now, you would also use those radiographs to check the positioning of the replanted tooth. Once verified that the tooth is positioned correctly, you want to stabilize the tooth with a flexible, functional splint. And the time frame for having that splint on should be about 14 days. The recommended antibiotic would be doxycycline or PenVK for 7 days. And the patient should be put on a chlorhexidine rinse for 7 days as well. If the patient is due for their tetanus booster, that should be done within 48 hours. At that point, you can release the patient and schedule for a follow-up visit in 7 to 10 days. So now let's talk about the scenario where Mrs. Smith comes to the office with the tooth in milk. So what's different? First of all, we do the assessment of the neurological issues. We check for alveolar bone fractures, root fractures. We do the same intraoral exam and radiographs as we did before when the tooth came back in the socket. But this time it's sitting in milk. So we prepare the socket, clean it out a little bit, irrigate it, remove the clot tissue. And then we take the tooth out of the milk, handling it very carefully by the crown, and irrigate it with saline. We can use saline to irrigate it. And then we carefully position it into the socket. We take our x-rays to verify positioning, and then we put on our flexible splint. Once the splint is placed, we talk to Mrs. Smith, let her know what the prognosis is. We explain the situation. We prescribe antibiotics, as we did before, the chlorhexidine rinse. We make sure that they have a tetanus booster that's up to date, and we schedule the patient for a follow-up visit in 7 to 14 days. Now, if the patient comes in where the tooth was not in a physiologic medium, such as Hank's solution or milk, and that could be water or saliva under the tongue, that's a non-physiologic media. In that case, we take the tooth out of that storage medium. rinse it with saline, and we drop it into Hank's balanced salt solution for about 10 minutes. And the purpose of this is to hopefully revitalize the PDL cells. So we drop it into Hank's balanced salt solution for about 10 minutes. If you don't have that in the office, you can put it in cold milk. But again, every GP should have a container of Hank's balanced salt solution. Now, once that has soaked, you're preparing The socket, you remove the tooth after that 10-minute period, drop it into the socket, take your x-rays to verify positioning, put on your flexible splint, prescribe the patient antibiotics, recommend the chlorhexidine rinse for seven days, and then, of course, recommend the tetanus booster if it's applicable. So now let's talk about one more scenario. In this case, Johnny's mother showed up at your office where the dry time exceeded 60 minutes. So you do the medical history, you take your radiographs, you do the same thing we discussed before, but now we have to treat the tooth completely differently. In fact, we want to remove the entire PDL. So the PDL that we were so set on preserving and being so gentle with, we now have to remove completely. We can do this in one of two ways. One option is to debride the root with soft pumice prophylaxis, wipe it down with gauze, and gently scale and replane the root. The other option is to soak the tooth in 3% citric acid for three minutes and rinse it well to fully remove the PDL. Now, once that is done, either option, we then take the tooth and place it in 1.23% sodium fluoride, which is an acidulated phosphate fluoride. And we do that for about 10 minutes. And once that's done, we replant the tooth. We obtain our radiograph to confirm positioning. and then we place our flexible splint. The same. prescription regimen, doxycycline or pen VK for seven days, chlorhexidine rinse for seven days, and then the tetanus booster if indicated. And we set the follow-up visit for seven to 10 days. Now let's talk about the follow-up visit. So at the follow-up visit, you do an intro exam, you take your radiographs to ensure everything looks okay, and then you begin root canal therapy. Now you can do root canal therapy on this tooth in one visit, or if the patient doesn't come back, In the time frame of 7 to 10 days, if it's a month or if it's even longer, you may want to do several regimens, three months at a time, of a calcium hydroxide slurry in the root canal system. And research has shown that this reduces the risk of resorption. But if they're back in 7 to 10 days, everything looks okay, you could go ahead and do the root canal treatment in one visit. If you see any signs of resorption, you definitely want to place calcium hydroxide in the canal, as I just described. And the long-term follow-up after the root canal therapy is complete is typically one month, three months, six months, 12 months, and annually for five years. And during those follow-up periods, radiographs should be taken to monitor the level of success of that re-implantation. In a future podcast, we'll be talking about treating a permanent tooth that has incomplete root formation. That's a whole nother topic with a little bit different treatment protocol. Thanks for listening. I'm Dr. Phil Klein.