James C. Kessler

Fundamentals of Fixed Prosthodontics


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pressure should be lower than 130/80 mm Hg.9,10

      Epinephrine in local anesthetic is contraindicated for patients with severe cardiovascular disease but not for patients with mild-to-moderate forms of the disease if the number of carpules used is limited to two or three.6 The rationale is that lessening of pain will decrease the endogenous release of epinephrine, which could be 20 to 40 times greater if the patient becomes stressed by pain.11 Retraction cord, however, does not provide any such potential benefit; therefore, cord containing epinephrine is contraindicated. Because of the availability of numerous alternatives for hemostasis and sulcus enlargement, the use of epinephrine-impregnated cords is not warranted.6

      Patients on oral anticoagulant therapy are the most likely to experience hemorrhagic problems during dental treatment. 12 They may be taking anticoagulants for a variety of reasons: prosthetic heart valves, myocardial infarction (MI), stroke (cerebrovascular accident [CVA]), atrial fibrillation (AF), deep venous thrombosis (DVT), or unstable angina.13 The two most widely used coumarin derivatives are warfarin sodium (Coumadin [Bristol-Myers Squibb]) and bishydroxycoumarin (dicumarol), both of which are vitamin K antagonists. 12

      Anticoagulation level is measured by the international normalized ratio (INR). A patient whose blood coagulates normally would have an INR of 1.0.13 Increasing the anticoagulant effect increases the INR.12 The INR range recommended by the American College of Chest Physicians14 and endorsed by the American Heart Association (AHA)15 is 2.0 to 3.0 in every situation mentioned previously, except for prosthetic heart valves, for which the INR range should be 2.5 to 3.5. The INR for artificial heart valves should not exceed 4.0.16

      The patient’s physician should be consulted to learn why the patient is on anticoagulants,12 the most recent INR value,13,17 and when it was taken. Anticoagulant therapy is the responsibility of the physician, not the dentist. However, the physician may recommend stopping anticoagulant therapy 2 to 3 days prior to treatment, which is the traditional management of patients on anticoagulants, although the dental literature indicates that this may not be the optimal approach.18

      An update of the recommendations by the AHA for prevention of infective endocarditis (IE) was issued in 2007.19 Guidelines were first published in 1955, and the most recent update before the present one was published in 1997. The current guideline greatly reduces the number of patients who should be premedicated, stating, “Only an extremely small number of cases of infective endocarditis (IE) might be prevented by antibiotic prophylaxis even if it were 100% effective.” 19

      Antibiotic prophylaxis for dental procedures now is recommended only for patients with cardiac conditions with the greatest risk of adverse outcome from IE19:

       Prosthetic heart valve

       Previous IE

       Congenital heart disease (CHD)

       Unrepaired cyanotic CHD

       CHD repaired with a prosthetic material for 6 months after repair

       Repaired CHD with residual defect at or near the prosthetic patch that would interfere with endothelialization

       Cardiac transplants that develop valvulopathy

      For patients with these conditions, prophylaxis is recommended for all dental procedures that involve the gingiva, the periapical region of the teeth, or perforation of oral mucosa.

      The antibiotic regimen now recommended is a single 2-g oral dose of amoxicillin for adults who are not allergic to penicillin, 30 to 60 minutes before the procedure.19 There is no need to prescribe a follow-up dose after the procedure. If the patient is allergic to penicillin, 600 mg clindamycin or 500 mg azithromycin or clarithromycin may be substituted. If none of these is acceptable, consult the patient’s physician or the guidelines article in the June 2007 issue of the Journal of the American Dental Association.19

      Patients with valvular dysfunction from rheumatic heart disease (RHD),20 mitral valve prolapse (MVP) with valvular regurgitation,21 systemic lupus erythematosus,22 and valvulopathy resulting from the diet medication fenfluraminephentermine (“fen-phen”)23 were once indicated for antibiotic prophylaxis, but following the 2007 guidelines set by the AHA, they no longer require premedication.19 Most unrepaired congenital heart malformations still do require antibiotic prophylaxis.19 Patients with cardiac pacemakers do not require prophylaxis.19

      With regard to artificial joints, the American Dental Association (ADA) states, “Antibiotic prophylaxis is not indicated for dental patients with pins, plates or screws, nor is it routinely indicated for most dental patients with total joint replacements. However, it is advisable to consider premedication in a small number of patients who may be at risk of experiencing hematogenous total joint infection.”24 For those patients not allergic to penicillin who do require premedication, 2 g amoxicillin taken orally 1 hour prior to the dental procedure is the antibiotic of choice. For variations of this regimen, the reader is referred to the advisory statement in the July 2003 issue of the Journal of the American Dental Association.24

      Patients who are on an antibiotic regimen prescribed to prevent the recurrence of rheumatic fever are not adequately premedicated to prevent IE.19 It is very possible that these patients will have developed strains of microorganisms that have some resistance to amoxicillin. If they require prophylactic antibiotic coverage, it would be wise to prescribe a different type than the one they are taking. Tetracyclines and sulfonamides are not recommended.

      Epilepsy

      Epilepsy is another patient condition of which the dentist should be aware. It does not contraindicate dentistry, but the dentist should know of its history in a patient so that appropriate measures can be taken without delay in the event of a seizure. Steps should also be taken to control anxiety in these patients. Long, fatiguing appointments should be avoided to minimize the possibility of precipitating a seizure.

      Diabetes

      More than 18 million Americans have diabetes, and another 41 million are “prediabetic.”25 Diabetic patients are predisposed to periodontal breakdown or abscess formation.26,27 Well-controlled diabetic patients should be able to report their self-monitoring blood glucose (SMBG) from that morning. This value, which they obtain by placing a drop of their blood in a glucometer, is a measure of their capillary plasma glucose. Their preprandial (fasting) reading should be in the 90 to 130 mg/dL range. Their peak postprandial (after meals) reading should be 180 mg/dL.28 A long-term measure of diabetic patients’ glycemic control is their glycosylated hemoglobin (HbA1c), a lab test that measures how much glucose is tied to red blood cells (Table 1-1). Its correlation with daily blood glucose numbers is 0.84.29 It can be considered the average blood glucose level over the previous few months.30

      Those whose diabetes is poorly controlled will have elevated blood sugar, or hyperglycemia, and could be adversely affected by the stress of a dental appointment. Hypoglycemia (low blood sugar) can also cause problems. A controlled diabetic (on medication) who has missed a meal or has not eaten for several hours may become sweaty, lightheaded, and disoriented. These patients usually carry some quick source of glucose, such as candy, which should be administered. Four ounces of a regular soft drink or fruit juice or several pieces of hard candy should help them recover quickly. Treatment should be halted for that appointment, and the patient should be monitored at the office until complete recovery can be confirmed. It would be wise to have a family member drive the patient home. Dental treatment for the diabetic patient should interfere as little as possible with the patient’s dietary routine, and the patient’s