**Note from the authors: This paper is a work in progress and is still being debated by the authors.  This is a preliminary report.**

systemic diseases caused by oral infection

Oral Microbes and Systemic Disease

Over the last twenty plus years, dental disease has been reported to be associated with numerous systemic diseases[1], including, heart disease[2] [3] ^{[4] [5] [6] [7] [8] [9]}, atherosclerotic lesions[10] [11], diabetes[12] [13], and neurological diseases[14] [15] [16] [17] [18] [19] [20] [21] [22] [23], brain abscesses[24], precancerous gastric lesions,[25] prostate cancer[26], and other cancers[27] [28] [29]. Although there have been numerous theories as to why this relationship exists, causation remains elusive[30].

In this paper, we will attempt to describe the dilemma dentistry is facing when trying to mitigate the problems derived from evidence that contradict our basic understanding of dental disease as related to systemic disease. New evidence forces us to change our methods of diagnosis and treatment of dental infection.

As-yet-uncultivated Oral Phylotypes

As-yet-uncultivated oral phylotypes have been detected in blood samples in episodes of bacteremia following dental procedures[31], ventilator-associated pneumonia[32], sinusitis[33], sputa from cystic fibrosis patients[34], and intrauterine infection leading to preterm birth or spontaneous abortion,[35] Nordquist and Krutchkoff[36], as well as others[37], propose evidence that a gross overpopulation of one or many spirochetal species plays an important role in periodontal disease. This finding is based on observation of chronic systemic disease symptoms that are reminiscent of other spirochetal diseases including Lyme disease, relapsing fever, and syphilis.

Traditional culturing techniques of identification of oral microbes in systemic diseases has proved impossible. However, advancements in DNA sequencing (and 16S RNA) analysis have proved invaluable. Siqueira and Rôças, reported 40-60% of the bacteria found in both healthy and diseased oral sites remain to be grown in vitro, phenotypically characterized, and formally named as species[38]. Therefore, the total number of different oral bacteria species has doubled from about 600 to as many as 1,200.

Like caries and periodontal diseases, the breadth of bacterial diversity in endodontic infections has been substantially expanded by culture-independent molecular methods.[39] Sakamoto et al[40] reported that uncultivated phylotypes accounted for approximately 55% of the taxa found in root canals of teeth with apical periodontitis. In pus aspirates from acute apical abscesses, as-yet uncultivated phylotypes encompassed approximately 24-46% of the taxa found[41] [42]. Rôças[43] reports, the “red complex” of bacteria known for their pathology in periodontal disease is also a contributor to apical infection in necrotic teeth. Another demonstrated that the microbiota of symptomatic periapical lesions is predominated by anaerobic bacteria but also contains substantial levels of streptococci, actinomyces, and bacteria not previously identified in the oral cavity[44].

Traditional culturing techniques are useless when evaluating possible pathogenic microbes in periodontal disease. Alternative methods need to be developed until most oral microbes can be identified and characterized. This will take years and potentially huge monitory expenditures to accomplish. Therefore, older techniques using phase contrast or dark field microscopy technology may be an alternative interim method to bridge the gap in DNA analysis knowledge.  There are, of course, services that use DNA data to provide information on imputed levels of specific ‘pathogens’.  While valuable, these markers are nowhere near as reliable as we might like to recognize ongoing disease processes or predict with great reliability the likelihood of further breakdown or disease control.

 Seek Out and Find oral Infection

The traditional method for diagnosing periodontal disease comprises using a mechanical periodontal probe with millimeter marks. This probe measures dental pockets around the teeth. When bleeding points occur, these are counted. The two measurements are then used for diagnosis. Considering the gravity of the relationship between dental disease and systemic disease, this method of mechanical diagnosis without evaluating the specific bacteria seems antiquated.  Since periodontal disease is an infection, it is paramount to observe the microbes causing the infection directly facilitating identification of specific groups of bacteria, their relative populace related to each other, and their mode and rapidity of movement.

We also need to recognize that the damage seen in periodontal disease is not simply from the direct action of the microorganisms against host structures.  Actually, it may well be the host’s REACTION to these microbes that results in the destruction of host structures.  It is the host that generates the matrix metalloproteinases that destroy the integral collagen.[45] Host levels of inflammatory response must also be modulated to minimize further structural degradation.

When diagnosing necrotic teeth, traditional periapical x-rays leave much to be desired. In the last ten years or so, new CAT Scan techniques have revolutionized dentistry.

Oral systemic Dental Diagnostic Tools

Diagnosis of periodontal disease: The periodontal microbe milieu is evaluated using the phase-contrast microscope electronically enhanced to 5,000X. The microscope is used to calculate imbalances of oral bacteria--specifically oral spirochetes--located in dental plaque. Observation of spirochetal overpopulation signifies a gross imbalance in oral microbes that is easy to recognize. Once detected, diagnosis and treatment options can be formulated. Since there are approximately 60 strains of oral spirochetes, most of which are, as yet, uncultivated, the microscope is the only available method of identification. Many spirochetes are so minuscule, that they are not visible below the electronic boost to 5,000X. In cases of severe periodontal disease, oral spirochetes can represent most of the visible oral bacteria by number.[46]

Diagnosis of infection located at the apex of necrotic teeth and failed root canal treated teeth: High definition Cone Beam CAT Scan (CBCT) technology is capable of very high definition using as many as 1000 slices. It can diagnose periapical lesions associated with abscessed teeth, including those lesions located below the root tips of ‘successfully’ treated root canal teeth. With the advent of this new technology, it has been embarrassingly evident that many lesions are not visible using traditional digital dental radiology. Research has shown that all x-ray-visible lesions associated with root canal teeth have an active inflammatory infiltrate[47] [48] and thus a source of microbes for seeding other parts of the body. Moreover, even if these lesions could be sterilized by treatment, without surgically removing the contents, such lesions may well spread inflammatory cytokines and other necrotic waste products throughout the system with further inflammatory or pathogenic effects. Plus, these oxygen starved nooks would serve as rich reservoirs for re-colonization of anaerobic microbes.

oral systemic Treatment Options

Periodontal disease: Treating periodontal disease requires identification, elimination of pathogenic species, and repopulating the crevicular microbiome. Research has shown that many oral pathogens enter and incubate within gingival sulcus epithelial cells[49]. Therefore, one efficacious method to eliminate these intracellular bacteria along with gingival sulcular microbes is vaporizing them with a micro-beam-tipped CO₂ laser. Then oral hygiene methods should be used to minimize reinfection. The problem remaining after sterilizing the diseased gingival sulcus is rebalancing the microbes. This critical reestablishing of the normal flora is the forefront of research today[50].  Ozone in a variety of forms has also been employed with success, according to personal reports from many practitioners.  There do not, however, appear to be many formal research papers published yet on this modality.[51]

Endodontic lesions: When extensive decay results in the death of a tooth with a resulting necrotic pulp, endodontic treatment is traditionally performed by dentists. Endodontic treatment is employed to remove and decontaminate the central infected portion of the nerve chamber and main canals of the tooth. However, it is well known by dentists that Root Canal Therapy (RCT) does not effectively remove all the infections associated with the necrotic tooth. Thousands of dentinal tubules exist within the tooth dentin, each containing a pain-sensitive mechanism that innervates the interior of a tooth. Once the tooth dies, these tubules serve as nutrient-rich nooks for colonization of bacteria and collect necrotic products that most likely cannot be removed by traditional endodontics. Therefore, extraction is the most predictable, reliable and effective method of treating necrotic teeth. Also, previously completed endodontic treatment should be evaluated at frequent for radiolucent apical lesions. Any evidence of bone loss at the apex predicts infection remaining associated with the tooth.

Therefore, to give the patient the best chance for eliminating oral infection, necrotic teeth with apical lesions must be sacrificed for the better health of the body in general.

Aggressive curettage of the bony socket, decontaminating the surrounding area, and grafting is advisable to allow healing with a lowered risk of pathologic infection. If patients insist on saving the tooth, thorough and aggressive endodontic therapy will be necessary. If an apical lesion exists, then a surgical procedure is needed to eliminate the lesion followed by rigorous curettage, decontamination, and grafting. It is highly advisable to give the patient verbal and written informed consent to verify understanding that some of the infection is not removed and can cause problems later.

The dental professional’s paradox or the calculus one must employ when making treatment decisions for patients is daunting.  It is not 100% certain of a causal relationship between periodontal/endodontic infection and systemic sequalae, but mountains of credible evidence have been collected over many years to convince even the most skeptical critic. For many this is not enough to change years of what is considered the Standard of Care treatment for dental disease. Nonetheless, given this uncertainty, should one then not make any effort to treat the potentially initiating diseases?  First, one must also weigh in the negatives, the downsides, the costs of DOING the treatment.  Our personal sense is that the downsides are minuscule by comparison to the devastating effects chronic infection and inflammation can potentially have on the entire organism in comparison to the vagaries and difficulties performing the dental treatments.

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Authors

William D. Nordquist, DMD, MS has practiced dentistry in San Diego California since 1973.  He received his BS in Chemistry from the Rochester Institute of Technology, his dental degree and post-doctoral MS degree from the University of Louisville.  He is an Honored Fellow in the American Academy of Implant Dentistry, a Master in the Academy of Implants and Transplants, and a Diplomate in the American Board of Oral Implantology/Implant Dentistry.  He lecturers internationally and published numerous books and professional articles concerning implant dentistry and/or chronic diseases.

William C. Domb maintained a very busy high-tech practice in Southern California east of Los Angeles, at the base of the San Gabriel Mountains in Upland and welcomed visitors from many states and countries to visit each year.  Primary focus has been on aesthetic restorative directions, but the practice has a number of other active centers such as headache-TMD, fresh breath, anesthesia and sedation dentistry, implantology, underlying biochemistry analysis, and minimally interventive/preventive services with a focus on the many uses of ozone.

Bill is a founder of the American Academy for Oral Systemic Health, AAOSH, and the producer of the website ZT4BG.com.  He founded the International Association of Ozone in Healthcare, currently its immediate past president.

Bill Landers is President of OraTec, a dental corporation specializing in Periodontal diagnostics and Anti-Infective therapy. He’s a leading expert on chairside and laboratory periodontal risk assessment technologies, including:  DNA testing, BANA enzymatic assays; BioScan phase contrast video microscopy; and cultures. He also co-developed the antimicrobial agent TheraSol and the Viajet oral irrigator.

Mr. Landers has an uncommon knack for making complex science subjects easy to understand and is a featured columnist for the RDH journal. His articles have also been published in Contemporary Dental Hygiene and Modern Hygienist.

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