Since the first successful organ transplant in 1954, advancements in medical technology, immunology, and pharmacology have increased the success rate of solid organ transplantation. Data from the United Network of Organ Sharing (UNOS) and the Organ Procurement and Transplantation Network (OPTN) catalog over 175,000 transplants between the years 2000 and 2015 (Optn.transplant.hrsa.gov 2016). Solid organ transplants by frequency and organ type include the kidney, most commonly as a result of end‐stage renal failure related to diabetes or high blood pressure, followed by the liver, as a result of hepatitis C or cirrhosis, next the pancreas, heart, lung, and intestine (nidcr.nih.gov 2016; Transplantpro.org 2016). In addition to solid organs, donated blood and bone marrow is used for hematopoietic (blood‐forming) stem cell transplantation (LLS.org 2016). A bone marrow transplant (BMT) or HSCT is commonly used in the replacement of bone marrow and blood constituents in the treatment of hematological disease and malignancy, non‐Hodgkin and Hodgkin lymphoma, leukemia, autoimmune disease, and solid tumors (Goldman 2006; Henig and Zuckerman 2014). The Center for International Blood and Marrow Transplant Research^® reports that 88,064 hematopoietic cell transplants occurred between 2009 and 2013 (Bloodcell.transplant.hrsa.gov 2016) showing an increase each year of 1000 people. All transplant procedures have lifelong consequences that include medication management and infection control. As the numbers of patients who survive either a solid donor transplant or hematopoietic transplant increases, the likelihood that a transplant survivor will visit a dental practice also increases.

In HSCT, high doses of chemotherapy and radiation are initially employed to destroy rapidly proliferating cancerous blood cells, which in turn damage the bone marrow where blood cells originate, replicate, and differentiate. After which, the HSCT aims to replenish blood‐forming, immature, stem cells that can differentiate into healthy red blood cells that carry oxygen, white blood cells (lymphocytes) that fight infection, and platelets that stop bleeding (National Cancer Institute 2016).

Stem cells that are used in HSCT are immature blood cells and are not to be confused with embryonic stem cells. Hematologic stem cells are also referred to as grafts and are harvested from either the patient’s bone marrow, peripheral blood system, or are donated. A self‐donated stem cell harvest is termed autologous or autogenic. Allogenic stem cells are sourced from matched donors or umbilical cord blood. Allogenic stem cells have the advantage of having been screened for contaminants, such as cancer cells, and for having a sufficient supply of healthy lymphocytes that are capable of destroying any remaining disease. The added advantage of these disease‐fighting lymphocytes is referred to as a graft versus leukemia (GVL) or a graft versus tumor reaction. However, these same lymphocytes also have the ability to detect the donor tissue as foreign and attempt to destroy it. This severe and often fatal complication is referred to as graft versus host disease (GVHD) (Goldman 2006; Burke et al. 2014).

The process of an autologous or allogenic stem cell transplant begins with chemotherapy treatment to induce remission and the reduction of cancerous blood cells. Stem cells are next collected from the patient and frozen. Once enough stem cells are collected, the patient undergoes a process called “conditioning” whereby high‐intensity chemotherapy and radiation are administered that destroys all remaining cells, cancerous and healthy, within the bone marrow. At this stage, patients are extremely immunocompromised and are isolated in a hospital transplant unit. The previously harvested or donated stem cells are then intravenously returned to the patient with the hope that they develop into healthy bone marrow and circulating blood cells (Burke et al. 2014).

The entire process takes several weeks, and complications resulting from a depressed, or absent, immune system occurs. These complications include opportunistic infections, graft rejection, side effects of medication, and most often, complications that take place in the oral cavity.

While there is little evidence to show dental infections complicate recovery after transplantation, pragmatic advice recommends eradication of existing infection prior to a transplant procedure. In many transplant centers across the world, patients are advised to be proactive and seek dental care prior to the transplant procedure, though the provision of cancer treatment is considered to be paramount and take precedence over operative dental procedures (Guggenheimer et al. 2003; Barker et al. 2004). Invasive dental treatment prior to transplant may delay cancer therapy, while at the same time, infections during the pre‐transplant and conditioning stages are to be avoided because there is a risk of infection and delayed healing (Guggenheimer et al. 2003; Barker et al. 2004; Goldman 2006).

In all stages of HSCT, the potential exists to develop oral conditions that include mucositis and xerostomia, as well as viral infections such as herpes simplex virus (HSV), fungal infections such as candidiasis, and bacterial infections related to the reduction in white blood cells. The literature describes xerostomia and mucositis as the most frequently encountered and debilitating consequences of chemotherapy and subsequent immunosuppression (Raber‐Durlacher et al. 2004; Burke et al. 2014; Nappalli and Lingappa 2015).

Mucositis evolves as epithelial cells lose the ability to divide and regenerate, allowing for tissue atrophy, a breakdown of mucosal integrity, subsequent tissue sloughing, and ulceration (Figure 3.3.1). The nonkeratinized mucosa of the ventral and lateral borders of the tongue, the floor of the mouth, soft palate, and buccal and labial mucosa are most affected (Raber‐Durlacher et al. 2004; Nappalli and Lingappa 2015). The ulcerations can be deep enough to permit opportunistic bacteria to penetrate and cause secondary systemic infections and sepsis. As a result of these infections, patients complain of significant pain that effects speech, swallowing, and eating. These conditions may also have an impact on the patient’s quality of life, nutritional stability, and recovery.

For purposes of documentation and treatment planning, mucositis is classified by the World Health Organization (Nappalli and Lingappa 2015):

The Multinational Association of Supportive Care in Cancer and the International Society for Oral Oncology have established oral care guidelines for patients with mucositis (Lalla et al. 2014). Patients will need to change their oral hygiene habits to avoid pain and aggravation of the ulcerated tissues. Small, soft toothbrushes or sponge tipped brushes (Toothette^®) are recommended, gentle flossing to avoid floss laceration, and saline (non‐medicated) mouthrinses. Pain management includes topical anesthetic mouthrinses.

Decreased salivary gland function or hyposalivation, is related to medication use and chemotherapy/radiation, which results in difficulty swallowing (dysphagia), alteration in taste (dysgeusia), and an increase in dental caries (Raber‐Durlacher et al. 2004; Burke et al. 2014; Nappalli and Lingappa 2015).Patient recommendations include frequent sips of water and to stay hydrated, use of salivary stimulants (e.g., xylitol gum), and salivary substitutes (e.g., Biotene^®). Prescription use of Pilocarpine as a salivary stimulant may be indicated (sialagogue therapy).

Guidelines (Table 3.3.1 and Table 3.3.2) for oral health management of the organ or stem cell transplant patient are offered by The National Institute of Dental and Craniofacial Research (NIDCR) (Goldman 2006; Nidcr.nih.gov 2014). These guidelines are free and available as brochures from the NIDCR website. Recommendations are separated into management of oral health before transplant and after transplant.

Primarily, the dental hygienist should obtain medical clearance from the patient’s medical oncologist before commencing with any treatment. The physician may request a complete blood count (CBC) to determine the patient’s ability to develop infection and tendency for excessive bleeding. Patients with a low absolute neutrophil count (ANC) may require prophylactic antibiotic pre‐medication (ANC is less than 1,000 μL). Excessive bleeding is determined by the prothrombin time and international normalized ratio (PT/INR) test and should fall within normal limits. Patients who have less than 20,000/μL platelets, may need a platelet transfusion and would need to be referred to a hospital setting for dental treatment (Raber‐Durlacher et al. 2004).

A dental hygienist who is fluent in dental oncology and transplant treatment protocols can educate patients and facilitate many of the oral health needs of a prospective and post‐treatment transplant patient. As an oral health‐care manager, the dental hygienist is part of the cancer care team that includes the patient’s primary medical oncologist and primary care physician, nursing staff, dietitian, speech therapist, psychologists, and other supporting members (Figure 3.3.2). The dental hygienist can be the patient’s liaison and contact for oral health‐care triage and maintenance.