Warfarin: Potental Dental Implant Complications?

In my opinion below are some helpful go-bys in the Dental management of the anticoagulated patient. REMEMBER TO ALWAYS CONSULT WITH THE PATIENTS PHYSCIAN PRIOR TO ALTERING ANY PRESCRIBED MEDS: Management is dependent on the type of procedure being performed, lab test results and type of medication the patient is taking. Aspirin or Plavix® therapy can be discontinued 7 days prior to surgery which should result in better hemostasis. These drugs can then be restarted safely 48 to 72 hours post-operatively. For patients taking Coumadin®, proper lab tests should be done and a consult to the physician may be required depending on lab results, medical condition, type of surgery being performed and the possible need for drug dosage reduction. Studies have shown that extractions can be done in patients with an INR of 2.5 to 3.5 safely, however the higher the INR, the more the need for hemostatic measures. Jeske found that the literature does not support the routine withdrawal of anticoaugulation therapy. Dentists should be prepared for bleeding that exceeds normal and may have to provide hemostatic measures. Giglio suggested that single tooth extractions or minimally invasive procedures such as crown lengthening where minimal bleeding is expected, are indicated if the INR is less then 4. In procedures where moderate bleeding is expected, such as block or gingival grafts, an INR of less then 3 is necessary. Little and Falace’s review of the literature, recommends that surgery may be performed with an INR of 2.0 to 3.0. For INR values of 3.0 to 3.5, it is recommended that the dosage of anticoagulant be altered depending on bleeding expected during the surgical procedure. Surgery should be delayed for values of 3.5 until the INR is within the therapeutic range of 2.0 to 3.5. Key labs tests to know: The platelet count provides a quantitative evaluation of platelet function. A normal platelet count should be 100,000 to 400,000 cells/mm3. A platelet count of less than 100,000 cells/mm3 is called thrombocytopenia and often can be associated with major postoperative bleeding. The average lifespan of a platelet ranges from 7-12 days. The bleeding time provides an assessment of adequacy of platelet count and function. The test measures how long it takes a standardized skin incision to stop bleeding by the formation of a temporary hemostatic plug. The normal range of bleeding time depends on the way the test is performed, but is usually between 1 and 6 minutes. The bleeding time is prolonged in patients with platelet abnormalities or taking medications which affect platelet function. This test assesses platelet function. The prothrombin time (PT) measures the effectiveness of the extrinsic pathway to mediate fibrin clot formation. It is performed by measuring the time it takes to form a clot when calcium and tissue factor are added to plasma. A normal prothrombin time indicates normal levels of Factor VII and those factors common to both the intrinsic and extrinsic pathways (V, X, prothrombin, and fibrinogen). A normal prothrombin time is usually between 10 and 15 seconds. Prothrombin time is most often used by physicians to monitor oral anticoagulant therapy such as warfarin. The partial thromboplastin time (PTT) measures the effectiveness of the intrinsic pathway to mediate fibrin clot formation. It tests for all factors except for Factor VII. The test is performed by measuring the time it takes to form a clot after the addition of kaolin, a surface activating factor, and cephalin, a substitute for platelet factor, to the patient's plasma. A normal partial thromboplastin time is usually 25 to 35 seconds. Partial thromboplastin time is most often used by physicians to monitor heparin therapy. The INR was designed for patients on chronic anticoagulant therapy. It allows comparisons from one hospital to another. A patient with normal coagulation parameters has an INR of 1.0. The therapeutic range for a patient on anticoagulant therapy is between 2.0 and 3.5.

There is obviously increased risk of any CV event if the patient is not in their "therapeutic" range of Coumadin (warfarin). The INR is a ratio which fluctuates on a daily basis based on the patient's Vitamin K intake. Pre-operative values of INR should be obtained prior to surgery. Usually if INR is less than 3.0, cessation of coumadin is usually not necessary. In addition, you can stage the procedure to several smaller procedures if you feel that the procedure may incur increased blood loss or a large surface area. With implants, the osseous bleeding usually stops once the implants are placed into the osteotomy site. The elevation of the flap will cause some bleeding, but should be easily controlled with basic hemostatic agents and techniques. If you are uncomfortable with bleeding and do not know or are aware of the various agents and treatments to obtain hemostasis, I would encourage you not to perform implant surgery in this particular patient. Refer to a qualified specialist.

That's a nice informative cut and paste reply above. Anyhoo, If this chap is on coumadin I typically figure it is for good reason. I personally don't withhold coumadin nor do I request from the physician it is withheld. After all how would you feel if your Mom had a stroke thanks to an implant or tooth extraction. To that end, I tell the patient to get an INR the day of the procedure or the day before. So long as it is 3.0 they are supratherapeutic anyhow and should return to their physician for some sort of adjustment. You're doing your pt a favor by not withdrawing their coumadin AND sending the pt back to the physician if they are supratherapeutic (or subtherapeutic) Finally, this is 100% purely elective procedure. The risk to their overall health should be minimized. If they throw a clot, even if the physician authorized the stoppage of coumadin, don't worry - you'll be named!

I would only do some implantplacements in a centre which have all the possibilities to cope with the complications. If you don't have the equipment to deal with these situations I wouldn't do the surgery. In this case I always refer. Maybe You can ask the physician to change the medication from warfarin to ascal. If you have a laser you can perform the incision with no bleeding. In these cases you must not only be aware of the bleeding during the operations, but even several hours beyond the operation the wounds can start bleeding again and putting the patient in a critical situation.So follow up is also a big issue!!!

Thanks Maz. I cut and pasted it from an article I wrote. I like your comment on remember this is an 100% elective procedure. Sometimes I think people forget that, since it is elective, doctors should take the time to make sure that the surgery is done as safe as possible. As far as adjustment of the INR for 3. Most literature supports proceeding with surgery for INR's of 3 or less without adjustment. I wouldnt send a patient for adjustment unless it was over 3. Just my opinion. Great discussion and insight in this thread.

All of the above statements are noteworthy. Excellent summary, Dr Toscano. The most significant statement to me, as a practicing oral and maxillofacial surgeon, is that if you are unable to manage the potential complications, don't do the surgery. In this case, the first question to ask is why the patient is on Warfarin - DVTs? atrial fibrillation? stroke? As MAZ noted, this is a purely elective procedure. Is it prudent, and truly in the patient's best interest, to subject them to the risks associated with modifying their anti-coagulation status and undergo a lengthy procedure? Next, consider your ability to manage complications. If any of these implants are to be placed in the posterior maxilla, and you happen to penetrate the antral floor, you could end up with significant bleeding into the sinus. Are you prepared to place a posterior nasal pack? [My personal pet peave - no one should attempt a sinus procedure, such as a sinus lift, unless they can manage severe sinus bleeding. No one should attempt to place an implant into a thin mandible unless they can manage a mandibular fracture]. If the patient is not adjusted to an INR of around 2.0, I guarantee you that you will see more bleeding coming out of the implant preparation site than you believed possible. It is true that placement of the implant "usually" will stop the external bleeding, but internal bleeding in the bone can continue, especially in the maxilla, which could result in an intra-osseous hematoma, which could result in bone necrosis. No further comment necessary. My final caution revolves around the anti-coagulation status itself. Many of the articles written about maintaining some level of anti-coagulation such as an INR in the 3.0 range are written by ivory tower institutionalists who do not practice in the real world. They contain statements such as it is "usually safe" or "probably safe" to extract teeth with higher INR ratios (above 2.5). Well, if you are, as I am, a solo practioner in a private office without immediate availability of emergency/supportive personnel such as would be available in a hospital, "usually" or "probably" does not cut it. I do not do procedures with an INR greater than 2.0. Additionally, as Dr T pointed out, these patients will generally begin taking their warfarin again the next day, and it is not uncommon to suddenly experience significant bleeding a couple of days post-operatively once the patient is again anti-coagulated. If this occurs in the middle of the night, are you prepared to deal with it? A personal story: I received a call from an ER MD at midnight one night begging me to come in and see a patient. When I arrived I found a lady in her early 90's that had two maxillary bicuspids removed by her GP earlier that day. She had a history of stroke and was taking Coumadin. I later found out that the GP had neither checked the patient's PT/PTT/INR, nor consulted with the patient's MD, but had recently read an article stating that it was not necessary to stop the patient's Coumadin for simple extractions. I also later found out the patient had a PT done the week before and the INR was 3.0. The patient was bleeding profusely. I administered local anesthesia, packed surgicel and kept pressure on the sockets with gauze - the blood was coming out faster than I could suction - I could not even see where it was coming from. I was unable to manage the situation from an ER bed, so I called for an OR and luckily one was available. We went into the OR immediately. I tried everything I knew - Surgicel, Gelfoam, Avitene, electrocautery. I kept pressure as hard as I could until my fingers were sore. The blood kept coming. I was ready to call head and neck surgery to attempt a maxillary artery ligation, but realized there was no time and it probably wouldn't work anyway. I started to suspect DIC. Finally after two hours in the OR I was able to get the bleeding to slow down. The patient somehow survived. She required transfusion of four units of blood - at one point she had a hemoglobin of 7 - and she spent several days in the hospital. I'm sure someone will comment that this is an isolated, rare incident, and that it does more harm overall to take patients off of anti-coagulants than to deal with post-operative bleeding. That's wonderful, but you be the one in my shoes next time. I have seen several other cases of significant post-operative bleeding after extractions by other Dentists, as well as one of my own, even with an INR of 2.5. I realize this rant is out of control but let me summarize: 1. Do no harm - make sure the benefit outweighs the risk. Ask yourself and your patient if the implants are worth the risk of stoke 2. Never personally alter a patients medication, even aspirin. This is considered practicing medicine without a license. Always consult with the patient's MD. 3. Do not undertake a procedure for which you may not be able to manage the potential complications. Thanks for listening (reading).

Wizzies excellent story, unfortunately it takes horror story’s like yours to remind us all that everything needs to be taken into consideration prior to putting blade to gum. A mentor of mine always said if you do enough surgery complications are inevitable. Even the most seasoned of surgeons can run into problems, so you need to be prepared. When I did my review of the literature, most of the studies in oral surgery and the perio literature pointed to surgery being safe up to an INR of 3.0. These studies showed that the risk of cardiovascular complication of altering the patients INR were greater then the risk of bleeding complications itself. I concur with your comments on “ivory tower institutionalists” and your story puts things in perspective. I think your comments are worth repeating: “1. Do no harm - make sure the benefit outweighs the risk. Ask yourself and your patient if the implants are worth the risk of stoke 2. Never personally alter a patient’s medication, even aspirin. This is considered practicing medicine without a license. Always consult with the patient’s MD. 3. Do not undertake a procedure for which you may not be able to manage the potential complications.” Consults are so important in this day when patients are on so many meds and have so many systemic complicating factors. Many problems can be avoided if you take the right steps prior and if your prepared for the unexpected. Great dialogue

In my opinion, those patients who are under treatment by any kind of anticoagulant drug,either oral warfarin or parenteral heparin, are contraindicated for dental implant therapy and should be excluded from this treatment modality.Warfarin, a 4-hydroxycoumarin derivative, is the most commonly used oral anticoagulant. It is a vitamin K antagonist, which acts by inhibiting the posttranslational carboxylation of glutamic acid residues that are found at several sites at the N-terminal end of coagulation factors II, VII, IX, and X. Warfarin also inhibits glutamate carboxylation on the amino terminus of the proteins C and S. The anticoagulant effect of warfarin results predominantly from reduction in factor II rather than a cumulative effect of lowering all four vitamin K–dependent factors elevating the patient's INR values towarads the higher end of the scale.A highly complicated and invasive oral surgical procedure like implant placement or bone grafting may potentially endanger the patients with an INR on the high end of the scale, and they should be considered at the risk of even future fatal bleeding episodes.The high end of the therapeutic range of INR is 3.5. Therefore, patients with INR above the therapeutic range are at increased risk of instantaneous bleeding. Increased inflammation of the oral tissues (e.g. around implants) in patients on anticoagulant drugs can contribute to excessive bleeding. The use of concomitant medications, including antibiotics, antifungals, nonsteroidal anti-inflammatory drugs, and other platelet aggregation inhibitors may affect a patient’s ability to achieve or maintain adequate hemostasis even after the procedure and prolonged therapy with certain antibiotics may potentially increase bleeding tendency because of vitamin K deficiency.When operting on patients receiving warfarin,minimizing trauma and minimizing the size of the surgical field is mandatory which would be beyond expectations in implant surgery.

dear sirs/madams never adjust patients warfarin dosage, the largest study by wahl demonstrates the disasterous effects of doing this, even at an INR of 4 you can safely place implants, construct a hard 1 to 2 mm splint will give you local control if your flap bleeds, most importantly dont do it if you cant deal with the complication.

Sir, the article that you are refering to, has been published about ten years ago (Dental Surgery in Anticoagulated Patients; Michael J. Wahl, Arch Intern Med. 1998;158:1610-1616.) and it seems that the aim of this publication is to find a way out, for some litigation cases. Nevertheless, I would like to quote some excerpts from the article. First: ( The focus of this article is to review only surgical dental procedures (extractions, gingival surgery, and alveolar surgery): nonsurgical dental procedures (professional cleanings, fillings, crowns, etc) have been shown not to present a significant bleeding risk). As you see, there is nothing been told about implant procedures.Dental simple extraction is almost the only procedure that is been referred to, throughout the article by Wahl. Second: (If a patient whose preoperative PT ratio or INR was within the therapeutic range were to be hospitalized or even die of postoperative hemorrhage after dental surgery, the defendant can show that many authorities state that there is minimal risk of such hemorrhage during dental procedures within the therapeutic range, while pointing out the risks of thromboembolism if therapy is interrupted). Third: (Patients receiving anticoagulant therapy who undergo dental surgery have not been shown to have more bleeding problems than patients with normal coagulation).No Comments ?????. It should be notified that the real problem with a hemophiliac or anticoagulated patient is not the bleeding at the time of implant placement surgery, but the real issue would be the spontaneous, insantaneous and occult bleedings from the soft tissues around the implant at the future, especially when they are irritated by any means.Happy Holidays.