Learning Objectives
After reading this chapter, the student should be able to:
- 1.
Recognize the various ways in which endodontic pathosis and systemic disease interact and some of the mechanisms of such interactions.
- 2.
Identify general consideration for the safe management of the endodontic patient with systemic disease.
- 3.
Identify the effects of diabetes mellitus, smoking, genetic predisposition, irradiation, sickle cell disease, and viral infections on the pathogenesis of endodontic pathosis and endodontic treatment outcomes.
- 4.
Determine the potential for acute and chronic endodontic infections to cause or contribute to systemic disease.
- 5.
Discuss the prognosis of the endodontic treatment in relation to the systemic condition.
- 6.
Identify age changes in the anatomy and physiology of the older dental pulp and periapical tissues, as well as differences in pathogenesis of disease and response to treatment.
- 7.
Identify factors that complicate case selection and discuss the differences in treatment between older and younger patients.
- 8.
Identify those elderly patients who should be considered for referral.
Health and Medical History
Successful dental management of a patient with extensive medical history depends on a thorough evaluation of the patient and on determining the diagnosis and treatment plan that takes risks and benefits into consideration. It is essential to determine and identify modifications to the dental treatment for a medically complex patient. Thorough discussion of the dental management and risk assessment of medically complex patients is beyond the scope of this chapter. However, some of the common illnesses will be explained. In patients with serious disorders, referral to an endodontic specialist may be appropriate. Specialist care is generally more expedient and offers better prevention and management of treatment complications (see Chapter 6 ).
The Systemic Health Assessment of the Endodontic Patient
In the review of the medical history and during clinical examination and treatment of the endodontic patient, the clinician needs to be keenly aware of specific areas in which systemic health affects the management of the patient. Importantly, endodontic patients should be managed in a manner that assures their safety, comfort, and well-being during and after the procedure (see Endo-Medical History 
).
Patients should be asked whether they have received prior endodontic treatment and how they view and feel about this form of dental treatment. Previous experiences or information that patients have from other sources may render them especially anxious about this procedure. Many patients have severe apprehension about having endodontic treatment, and their care may need premedication, sedation, or other auxiliary methods that facilitate the experience for them. Occasionally, especially in the case of children, moderate to deep sedation or general anesthesia may be the only practical approach to treating them.
Endodontic patients especially should be asked about the history of chronic pain of any type. These patients are at an increased risk of postoperative and of persistent pain, and this aspect should be reviewed with them during the informed consent process (see Chapter 5 ).
Endodontic treatment involves the effective use of local anesthesia (see Chapter 8 ), adjunctive analgesics, and antibiotics. Therefore complete history of cardiovascular, endocrine, respiratory, hepatic, and renal systems should be obtained. Preoperative vital signs, such as blood pressure, pulse, and respiration, should be recorded. Occasionally, preoperative glycemia (blood glucose measurement or glycated hemoglobin [HbA 1c ]) are needed to assess the control of glycemia for diabetics or the need for referral to a physician in patients at high risk of diabetes (see 
for A 1c Now Measurement). International normalized ratio (INR) is required for the patient on Coumadin (warfarin), especially before surgical treatment. The INR is a standardized way of expressing the prothrombin time test (PT). Heparin is an anticoagulant that will prolong partial thromboplastin time, activated PTT (PTT, aPTT). Detailed lists of medications, allergies, previous hospitalizations, medical and surgical treatments, and previous untoward reactions should be collected. Like any dental procedure that results in risk of bacteremia, the risk of infective endocarditis or of late artificial joint infection should be identified, and appropriate antibiotic coverage should be instituted whenever indicated according to current guidelines. The American Dental Association has recently provided guidelines for the use of systemic antibiotics for endodontic patients (see https://ebd.ada.org/en/evidence/guidelines/antibiotics-for-dental-pain-and-swelling?utm_source=EBDsite&utm_content=guidelines for guidelines).
Allergies to specific materials or reagents used in endodontics are rare. Reports of hypersensitivity to gutta percha, amide-based local anesthetic agents, sodium hypochlorite, and nickel (present in nickel titanium files) should be considered in the treatment of the endodontic patient. Consultations with a medical specialist in hypersensitivity reactions should be made before treatment decisions are made. Referral to an endodontist would be indicated for management of patients with true allergy to any endodontic materials.
Physical Examination: Vital Signs
Vital signs are an important component of patient treatment and give the health care provider information regarding the current medical status of that patient (see Chapter 4 ). Blood pressure, heart rate, respiratory rate, and temperature should be recorded. In some cases, fasting blood glucose and/or the values of HbA 1c are recorded or documented, too (see 
of A 1c Now Measurement). This information helps the clinician better understand the patient’s physiological state.
Systemic Considerations
Dentists are members of the health team whose role ultimately is to ensure that the patient’s health, including oral health, is maintained at an optimal level. Over the past two to three decades, the close relationship between oral health and systemic health has gained much attention, and many advances in this area have been achieved. In the early part of the 20th century, endodontic infections were thought to be a focus of infection that may lead to a variety of ailments and chronic diseases in the body. Although the systemic spread of acute oral infections is clear, recent objective research has identified compelling associations between systemic disease and chronic oral infections, including endodontic infections. The available evidence on the relationship between endodontic pathosis and systemic disease is presented here.
Endodontics and Systemic Disease
With regard to the relationship between endodontic pathosis and systemic disease, the practitioner needs to be aware of three factors: systemic diseases that mimic endodontic pain or periapical radiolucency (see Chapter 4, Chapter 5 ), systemic diseases that may accelerate or potentiate pulpal pathosis or influence treatment outcomes, and conditions in which the endodontic infection may initiate or contribute to an infection in a distant site or another systemic disease.
Systemic Diseases That May Influence Endodontic Pathosis or Its Treatment
Certain systemic conditions were reported to be associated with pathogenesis of endodontic lesions in a recently published systematic review. Specifically the authors found that there was a moderate risk for and association of cardiovascular disease and diabetes with endodontic pathosis. In another systematic review, the authors investigated the interaction of systemic disease with endodontic healing and reported that certain systematic diseases are associated with endodontic healing. Patients with medical conditions that compromise their immune response may have a less favorable endodontic treatment outcome. Though the mechanism or pathway for this interaction remains speculative at this time, it is critical to note that the patient’s medical condition is preemptive to his or her dental care and prognosis.
Endodontic Disease May Initiate or Contribute to Systemic Diseases
The oral cavity is the first component of the digestive system and has a large component of the human microbiome (as noted in Chapter 1 ). The diversity of microorganisms in the mouth is related to its exposure to dietary and environmental factors and to the unique characteristics of the oral environment. Deleterious effects of these microorganisms are prevented by an intact mucosal lining, which is capable of a formidable immune response, and by oral hygiene measures that limit the progression of oral microbial biofilms. The dental pulp is protected from bacteria by intact enamel and dentin, whereas the periodontium is protected by periodontal attachment and sulcular epithelium. With marginal periodontitis or pulpal pathosis, these barriers are absent, and the oral microflora may have free access to the periodontium or periapical tissues; in this way, microorganisms that are normally commensals become pathogenic.
Acute Endodontic Infections
There is no doubt that bacteria from acute endodontic infections can cause bacteremia and can migrate to local lymph nodes and fascial spaces. Case reports have documented the association of acute endodontic infections with brain abscess, mediastinitis, and fatal necrotizing fasciitis. In fact, researchers reported that about 8000 patients in the United States are hospitalized annually for periapical abscesses, some of whom have comorbid conditions such as diabetes or hypertension. Therefore it is essential for the practitioner to obtain adequate diagnostic data for patients with acute endodontic infections and to evaluate their progress carefully, in case they need referral for management in a hospital setting. Patients with abscesses should have their temperature measured, and they must be evaluated for lymphadenopathy, malaise, and fascial space infection. These patients should receive prompt and complete elimination of local irritants, including drainage of the swelling. Those with a fascial space infection (cellulitis) also should be treated with adjunctive antibiotics and, most important, should be monitored carefully until their condition improves (see Chapter 9 ).
Chronic Endodontic Infections
The evidence for the presence of bacteria in periapical lesions and their escape systemically in chronic endodontic infections is less conclusive. Animal and human studies show that this is infrequent in primary lesions ( Fig. 2.1 ). Studies have found that the number of bacteria in persistent periapical lesions after unsuccessful treatment may be much higher. Teeth with chronic apical abscesses and sinus tracts have been reported to have very complex bacteriologic conditions with biofilm attached to the outer root surfaces in 17 out of 24 teeth.
One way to investigate this potential for bacteria in chronic infections to travel from the endodontic environment to participate in the pathogenesis of systemic disease is to determine the epidemiologic associations between the two forms of disease. One report associated periapical lesion-years (the number of years with a periapical lesion) and incident coronary heart disease in men younger than age 40. Another study of patients with myocardial infarction (MI) reported a significantly higher number of patients with missing teeth and teeth with periapical lesions in the MI group compared with controls. An additional large cohort study of male health professionals showed that the presence of coronary heart disease was significantly associated with the presence of one or more root canal–treated teeth (as a marker of pulpal and periapical disease). In a systematic review of longitudinal cohort studies, the authors reported a moderate risk of causation. However, they raised questions about the interrelationship of these different diseases, warranting further animal and human studies. Interventional studies would be required to prove causation, and those are clearly difficult to perform, given the ethical issues involved.
Diabetes Mellitus
Diabetes mellitus is one of the most significant chronic diseases that affects humans worldwide. In the United States about 30.3 million people, or 9.4% of the U.S. population, had diabetes in 2015. This total included 30.2 million adults age 18 or older, or 12.2% of all U.S. adults. About 7.2 million of these adults had diabetes but were not aware that they had the disease or did not report that they had it. Diabetes is not curable, and it has serious complications, including cardiovascular disease, neuropathy, renal disease, blindness, limb amputations, and periodontal disease.
Health care practitioners generally know that diabetics have a higher prevalence of teeth with periapical lesions. The longitudinal treatment outcome is generally not different for diabetics and nondiabetics. However, if the outcomes of cases with and without preoperative periapical lesions are separated, a notable difference is observed. In cases with preoperative lesions, diabetics are significantly less likely to have successful treatment than do nondiabetics, especially when controlling for several other confounding factors.
People with diabetes may have compromised healing, particularly those with higher glycemic rates and with preoperative endodontic infection, for several reasons. These individuals may select for specific microorganisms that may be more virulent. They may have a variant of inflammatory cells, such as monocytes, characterized by excessive secretion of inflammatory mediators, including bone resorptive cytokines, that are critical for the development of periapical lesions. The increased glycemia may also spontaneously result in excessive production of advanced glycation end products (AGEs). AGEs interact with their receptors (RAGEs), resulting in the production of bone resorptive mediators, which may lead to persistence of the periapical lesions.
Hypertension
Hypertension is a sign of cardiovascular disease that may indicate a variety of underlying conditions and comorbidities, including diabetes. Hypertension appears to be associated with reduced survival (meaning continued presence of the tooth in the mouth) of endodontically treated teeth. In a study of the Indian Health Service in two U.S. states, 4500 patients were examined. It was found that patients who had diabetes and/or hypertension had a significantly reduced chance of retention of endodontically treated teeth within a period of 10 years. In another cohort that included more than 49,000 teeth followed for about 2 years, researchers found that the presence of diabetes and/or hypertension resulted in significant reduction in tooth retention. It is noteworthy, however, that the study of tooth survival in the absence of exact endodontic diagnosis and assessment of periapical health is confounded by the fact that diabetes and cardiovascular diseases are also associated with periodontal disease, which may have played an important role in the loss of these teeth.
Risk for Osteoradionecrosis or Osteonecrosis of the Jaw
Patients who have undergone radiation therapy for the treatment of malignancies in the craniofacial area are at risk of osteoradionecrosis at the site of a surgical procedure such as tooth extraction. Therefore many of these patients have teeth that would ordinarily not be amenable to treatment but that are retained with endodontic treatment to avoid the risk of osteoradionecrosis. A report documented the treatment outcome in 22 patients treated endodontically after having received 50 Gy irradiation in the area within the preceding 6 months. After a mean of 19 months, successful treatment was found in 91% of the patients, which was consistent with treatment averages for normal patients in other studies. However, treatment of patients who have undergone radiation therapy is frequently complicated by fibrotic tissues that do not permit adequate mouth opening ( Fig. 2.2 ). About 66 to 70 Gy of radiotherapy has been reported to result in progressive decrease in pulp vitality testing and electric pulp testing at 12 months. Also, dry mouth results in recurrent caries, compromising the prognosis.
Over the past decade, it has been recognized that patients undergoing bisphosphonate therapy may be at risk for bisphosphonate-related osteonecrosis of the jaw (BRONJ). This risk is greater in patients receiving intravenous (IV) bisphosphonates, particularly if more than one agent is used simultaneously, and the risk increases with the duration of bisphosphonate use and with surgical procedures, such as extractions. Although rare, BRONJ may occur after endodontic treatment or endodontic surgery. When nonsurgical endodontic treatment is performed on a patient receiving IV bisphosphonates, care should be taken not to injure the soft tissue. For example, the clamps should be carefully placed to avoid injury to the soft tissues and alveolar bone .
Oral bisphosphonates pose a much lower risk of BRONJ. Endodontic outcomes are not different between patients taking oral bisphosphonates and other patients.
Viral Infections
HIV/AIDS
When the human immunodeficiency virus (HIV) was first identified, practitioners were concerned that patients with HIV infection would be so compromised that severe complications would ensue with endodontic disease and/or endodontic treatment, particularly in patients whose cluster of differentiation 4 (CD4+) cell count had dropped below 200/mL. However, a cohort study of patients with acquired immune deficiency syndrome (AIDS) who had received various oral health procedures documented that the patients did not appear to suffer any undue pain or infection with endodontic treatment. In addition, 1 year after treatment, no difference was seen in the outcomes of treatment between patients who were HIV positive and those who were not infected with the virus.
Herpes Viruses
There are many different types of herpes viruses that affect humans. These types include varicella zoster virus (VZV), which causes herpes zoster infection; human herpes viruses (HHV1-8); human cytomegalovirus (HCMV); and Epstein-Barr virus (EBV).
Herpes zoster infections frequently represent a diagnostic dilemma, because after the herpetic blisters heal, the patient may suffer from postherpetic neuralgia, which mimics endodontic pain. Careful documentation of the medical history and diagnostic tests should help the practitioner identify this condition and make the right decisions and/or referrals. However, herpes zoster infection may also induce spontaneous pulpal pathosis.
Periapical lesions in patients infected with HCMV and/or EBV, but not herpes simplex viruses, may be larger and more painful. In addition, irreversible pulpitis or acute endodontic infections may be associated with a higher incidence of EBV or the HHV pathogens. However, it is not yet conclusively known whether the viral association potentiates the development of more aggressive forms of endodontic pathosis or whether the findings of the small studies and case reports available were merely coincidental. One systematic review has not identified significant associations between HCMV or EBV and symptomatic endodontic pathosis.
Sickle Cell Anemia
Sickle cell anemia is characterized by a congenital abnormality of red blood cells that results in deficient oxygenation of the blood. A milder form of the disease, known as sickle cell trait, results from homozygous transmission of the affected gene. Oral findings of sickle cell anemia include the radiographic “stepladder” trabecular pattern of bone, enamel hypomineralization, calcified canals, increased overbite, and overjet. An older case series showed the spontaneous development of pulpal pathosis in some noncarious teeth in patients with sickle cell anemia. More recently, it was shown that patients with sickle cell anemia have a significantly higher incidence of orofacial pain than controls and have pulp necrosis in 6% of their teeth that have no other apparent etiologies in comparison with none in the controls.
Smoking
The oral health problems of smoking, including the increase in periodontal disease, mucositis, and oral premalignant and malignant lesions, have been well documented. Recently, there has been an interest in the association of smoking with pulpal and periapical diseases. Smoking is also associated with a high prevalence of periapical lesions and with incident root canal treatment as a marker of pulpal and periapical diseases. The incidence of root canal treatment (as a marker of endodontic disease and its treatment) was also increased with the duration of smoking and reduced in smokers who stopped smoking more than 9 years before the evaluation time. Smoking was also shown to increase the incidence of pain and/or swelling after endodontic surgery. Smoking has been reported to change the immunoregulatory function of the cytokines and chemokines in dental pulps. In addition, smokers tend to have more postsurgical infections than do nonsmokers.
Genetic Predisposition
Several gene polymorphism associations have been made with endodontic treatment outcomes. Thus interleukin (IL)-1β allele 2 was found to be associated with reduced healing after endodontic treatment. Gene polymorphism in IL-1β, IL-6, and IL-8 have been reported to be associated with apical periodontitis.
It is noteworthy, however, that these associations do not prove causation and that studies with large sample sizes are needed to confirm these initial findings.
- 1.
Why is it important to be familiar with the patient’s medical history?
- a.
Most patients require antibiotic treatment. Thus the clinician needs to premedicate most patients.
- b.
Most patients are in pain and need to be premedicated with antibiotics, analgesics, and narcotics.
- c.
As with any invasive procedure, there is a high prevalence for bacteremia.
- d.
The clinician needs to be keenly aware of the patient’s systemic health as it affects the dental management.
- a.
- 2.
Reports of hypersensitivity to gutta percha, amide-based local anesthetic agents, sodium hypochlorite, and nickel (present in nickel titanium files) have been reported, but it is rare.
- a.
True
- b.
False
- a.
- 3.
Diabetes has which of the following complications:
- a.
Neuropathy
- b.
Liver dysfunction
- c.
Blood disorder
- d.
Hepatitis
- a.
- 4.
There are several reasons why diabetics may have compromised healing. All the following are reasons except one. Which one is the EXCEPTION?
- a.
Impaired immunologic cells
- b.
More virulent microorganisms
- c.
Variant inflammatory cells
- d.
Reduced glycemia
- a.
- 5.
What dose of radiotherapy has been reported to result in progressive decrease in pulp vitality testing and electric pulp testing at 12 months?
- a.
10 to 20 Gy
- b.
30 to 40 Gy
- c.
50 to 55 Gy
- d.
66 to 70 Gy
- a.
Presentation of Endodontic Disease in the Older Adults
Endodontic considerations in older adult patients are similar in many ways to those in younger patients, but there are some notable differences.
The number of persons age 65 or older in the United States exceeds 39 million, and they are expected to comprise 20% of the population by 2020. Their dental needs will also continue to increase. More older adult patients will not accept tooth extraction unless there are no alternatives. They have a high utilization rate of dental services. The expectations for dental health parallel their demands for quality medical care. An even more important consideration is that these dentitions will continue to experience caries and decades of dental disease, in addition to restorative and periodontal procedures specifically ( Fig. 2.3 ). These factors all have compound adverse effects on the pulp and periapical and surrounding tissues ( Fig. 2.4 ). In other words, the more injuries inflicted, the greater the likelihood of irreversible disease, and thus the greater the need for treatment. The number of older adult endodontic patients is increasing and will continue to do so.
