November/December 2011, Volume 32, Issue 4
Published by AEGIS Communications
Salivary Diagnostic Testing: A “Game Changer” for Patient Evaluation
Despite an abundance of recent advances in dental technology, many dentists continue to struggle with how to best diagnose and treat periodontal disease and assess risk for early stage oral malignancies. As clinicians evaluate new diagnostic modalities, the health risks and benefits to the patient must always be the primary concerns. In today’s challenging economic climate, the financial risk and benefits to both the patients and the practice also need to be considered.
By properly incorporating noninvasive screening procedures like salivary diagnostics into the practice’s armamentarium, much of these concerns can be addressed. More specifically, the clinical procedures and science of salivary diagnostic testing can have a positive impact on patient outcomes with minimal to no health risks or financial concerns for all parties involved.
Saliva, especially whole saliva, can be easily collected from the patient and tested in a laboratory to help accurately determine if the patient is at an increased risk for periodontal disease. Whole saliva is composed of fluids from major and minor salivary glands, gingival crevicular fluid, epithelial and immune cells, and food debris.1
What’s more, the fact that the same genetic information found throughout the body is also found in saliva is what makes it effective in testing for various systemic conditions.1 By combining interpretation of the information obtained through clinical, radiographic, and salivary DNA analysis, a more accurate evaluation of the patient can be developed, which in turn assists in achieving more individualized and effective treatment.
The Science of Salivary Diagnostics
Human saliva contains human DNA as well as bacterial and viral DNA. Both types of DNA can be extracted and analyzed through a laboratory process called polymerase chain reaction (PCR), which is a technique for cloning DNA in a test tube. Cloning is necessary to ensure that a large enough DNA sample is obtained to perform detailed lab analysis. More than 1 billion DNA strands are produced from the original single strand after approximately 90 minutes of laboratory preparation.
Not only does the genetic information derived from the PCR process play an integral part in the early diagnosis of diseases, but also in confirming the presence of a genetic polymorphism, or variant, which can indicate whether a person has a predisposition or increased susceptibility to a specific disease or condition. This ability to noninvasively extract accurate genetic data from a simple saliva specimen is a diagnostic “game changer” that has the patient’s best interest in mind and can easily be incorporated into any dental practice.
The Business of Salivary Diagnostics
Salivary diagnostic testing not only presents dentists with the ability to provide a higher standard of care for patients; it also can help increase the patient’s understanding of the overall value of comprehensive dental care. First of all, it is less invasive than taking a blood sample; patients and dental team members alike typically more favorably accept salivary diagnostic testing. Patients are more willing to donate a saliva sample than have blood drawn.
Secondly, it is easy to incorporate salivary diagnostic testing into an existing office workflow, because administering the tests takes very little time in the scheduled appointment. Dental team members appreciate the ease of the collection process, in which the patient is normally the one handling the user-friendly specimen container prior to it being sent to the laboratory for analysis, thus further minimizing infection control issues.
With proper training on the purpose of the tests and how to perform them, both the hygienist and dental assistant can become effective, sincere advocates of salivary diagnostic testing, recommending what they believe to be in the best interest of the patient. The appropriate salivary tests can be automatically incorporated into the normal routine of a new patient’s initial examination and introduced to active patients with periodontal disease who will begin treatment or are currently undergoing maintenance therapy.
Specific Application: Periodontal Disease
Until now, to determine if a patient has periodontal disease, dentists typically utilize radiographs, evaluate clinical symptoms (eg, inflamed gingiva, bleeding upon probing), and calculate pocket depth. The tools and criteria used to make a periodontal diagnosis are subjective, and new diagnostic tools have been needed to help detect earlier stages of disease, preferably before it becomes a chronic infection. Salivary diagnostic testing can help with early detection (Figure 1).2 By analyzing patient saliva, biomarkers for bone loss seen in periodontal disease can be measured.2 Additionally, specific bacteria can be evaluated to establish the type and extent of periodontal disease.1
Studies show that patients with periodontal disease have higher levels of immunoglobulin (IgA) than healthy patients and these levels can be effectively reduced with treatment.2 Patients with periodontal disease can be periodically tested to determine if the process is active due to various bacteria and if the risk is great due to the interleukin-1 (IL-1) marker that is associated with inflammation.
Salivary test results can help the clinician formulate an individualized therapy plan for the patient’s office and home care. In regard to oral pharmacology, testing provides a way to select the specific, correct adjunct antibiotic and dosage rather than using a generalized approach.
Retesting the patient’s saliva after therapy has been performed can help the clinician gauge if the patient’s treatment has been successful or if there is a need for additional treatment and/or a further need to seek the care of a specialist. The information gained with a posttreatment salivary assessment can help facilitate a dialogue in which the clinician can either praise the patient for his or her continued progress or discuss why little to no improvement has occurred following therapy. If therapy is not working, the general practitioner can refer the patient to a specialist to help with treatment.
In regard to restoring dentition, most patients believe a dental implant can restore esthetics and function to teeth lost to periodontal disease, trauma, or congenital defects; however, few realize that the implant area needs meticulous hygiene care at home and in the dental office. Bacteria can adhere to the implant as it would with the natural tooth. Conditions for bacteria to thrive and multiply around the implant can cause peri-implantitis, which may lead to implant failure. Gram-negative anaerobic bacteria are implicated in implant failure, especially if there is active periodontal disease.3 Failure of dental implants in edentulous patients has been attributed to the anaerobic bacteria found in periodontal disease.
Since a patient’s saliva harbors the bacteria,4 it is suggested that the periodontal status and microflora be determined before placing an implant and an evaluation be performed periodically.4 This can be effectively achieved through salivary diagnostic testing.
Integrating salivary testing into the dental practice can be beneficial. Saliva is shown to harbor bacteria and proteins that can be tested. The principal application can be for periodontal disease and implants. If the bone is not healthy due to various inflammations and bacteria, failure of implants may be evident and periodontitis may persist. Patient care and treatment should be emphasized, which will improve the quality of work and revenue generated by the dental office. As healthcare providers, dental practitioners can explain and link the gap between oral and systemic health by testing the fluid that is found in their area of expertise, the oral cavity.
1. Miller CS, Foley JD, Bailey AL, et al. Current developments in salivary diagnostics. Biomark Med. 2010;4(1):171-189.
2. Giannobile WV, Beikler T, Kinney JS, et al. Saliva as a diagnostic tool for periodontal disease: current state and future directions. Periodontol 2000. 2009;50:52-64.
3. Bobia F, Pop RV. Perimplantitis: Aetiology, diagnosis, treatment. A review from the literature. Current Health Sciences Journal. 2010;36(3). www.chsjournal.org/archive/vol-36-no3-2010/updates/periimplantitis-aetiology-diagnosis-treatment-a-review-from-the-literature. Accessed October 3, 2011.
4. Emrani J, Chee W, Slots J. Bacterial colonization of oral implants from nondental sources. Clin Implant Dent Relat Res. 2009;11(2):106-112.
About the Author
Tanya A. Wright, DDS
Assistant Professor, Oral and Diagnostic Sciences
Meharry Medical College School of Dentistry
Oral Pathology Consultant
OralDNA Labs Inc.