Research: Dental Infections, Root-Fillings and Health
I. Introduction
Prestigious dental researchers and doctors such as Westin Price (DDS), Frank Billings (MD), Milton Rosenow (MD), Charles Mayo (MD) and Martin Fischer (MD) during the early part of the past century based on extensive research concluded that the majority of chronic systemic disease is due to infections in the tonsils and/or teeth that are usually symptomless and very difficult to detect.
Recently there has been renewed interest in the incidence and effects of oral focal infections. It has been recognised, that oral infection especially periodontitis can cause and affect the course of a number of systemic diseases, such as: cardiovascular disease, cerebrovascular disease, atheromatous peripheral vascular disease, bacterial pneumonia, diabetes mellitus, osteoporosis, and adverse pregnancy outcome. Studies found that treatment of dental infections could bring significant improvement in insulin resistance and other conditions.
A significant association has been demonstrated between periodontal disease or other dental related infections and cardiovascular disease. Recent studies have demonstrated systemic antibodies to selected periodontal parthogens. A recent study analysed the prevalence of dental treatment and oral infections related to the development of infective endocarditis (IE). A retrospective study of 103 cases of IE diagnosed from 1997 to 1999 was conducted in Galicia, Spain. According to the Duke's endocarditis criteria (1994), 87 cases (84.5%) were considered definite IE. A presumed oral portal of entry was recorded in 12 patients (13.7%). Oral infections were held responsible in six cases while the remaining six had received dental treatment in the previous three months (three tooth extractions, one scaling, one cleaning, one fillings). In eight cases of IE, typical oral pathogenic microflora was identified, with Streptococcus viridans being the most frequent. In four of these patients no previous cardiac disease was recorded. The need for increased oral hygiene and improved dental care should be emphasised on preventing IE of dental origin.
Chronic dental infections, even of low intensity, may cause the development of atherosclerotic changes in arteries that lead to coronary heart disease. There are many risk factors for atherosclerosis, but the most important are endothelium function disturbances, platelets activation and oxidative changes of plasmatic lipoproteins. Among factors that can induce the epithelium lesions bacterial factor may play an important role. In consequence of the bacterial cell breakdown place the release of endotoxins takes, that lead directly to the damage of endothelial cells.
Apart from this direct effect endotoxins activate the phagocytes releasing superoxide reactive radicals, that cause lesions of endothelium. Probably the most widespread chronic bacterial infections in human are the diseases of periodontium and teeth and their inflammatory complications. Oral cavity is colonised by 300-400 bacterial species. In the case of dental bacterial infections bacteraemia occurs after such procedures as tooth extraction, endodontic treatment, therapeutic and hygienic interventions on periodontal tissues. The results of many investigations show the relationship between the oral status (dental and periodontal diseases as chronic oral infections) and disorders of cardiovascular system.
Metabolic syndrome and type 2 diabetes (T2DM) resulting from sustained hyperglycaemia are considered as risk factors for cardiovascular disease (CVD) but the mechanism for their contribution to cardiopathogenesis has not been well understood. Hyperglycaemia induces nonenzymatic glycation of protein-yielding advanced glycation end products (AGE), which are postulated to stimulate interleukin-6 (IL-6) expression, triggering the liver to secrete tissue necrosis factor alpha (TNF-alpha) and C-reactive protein (CRP) that contribute to CVD pathogenesis. Although the high prevalence of periodontitis among individuals with diabetes is well known by dental researchers, it is relatively unrecognised in the medical community. The expression of the same proinflammatory mediators implicated in hyperglycaemia (i.e., IL-6, TNF-alpha, and CRP) have been reported to be associated with periodontal disease and increased risk for CVD.
Ford et al review the evidence for the interaction of oral disease (more specifically, periodontal infections) with cardiovascular disease. Cardiovascular disease is a major cause of death worldwide, with atherosclerosis as the underlying aetiology in the vast majority of cases. The importance of the role of infection and inflammation in atherosclerosis is now widely accepted, and there has been increasing awareness that immune responses are central to atherogenesis.
Chronic inflammatory periodontal diseases are among the most common chronic infections, and a number of studies have shown an association between periodontal disease and an increased risk of stroke and coronary heart disease. Although it is recognised that large-scale intervention studies are required, pathogenic mechanism studies are nevertheless required so as to establish the biological rationale. In this context, a number of hypotheses have been put forward; these include common susceptibility, inflammation via increased circulating cytokines and inflammatory mediators, direct infection of the blood vessels, and the possibility of cross-reactivity or molecular mimicry between bacterial and self-antigens.
In this latter hypothesis, the progression of atherosclerosis can be explained in terms of the immune response to bacterial heat shock proteins (HSPs). Because the immune system may not be able to differentiate between self-HSP and bacterial HSP, an immune response generated by the host directed at pathogenic HSP may result in an autoimmune response to similar sequences in the host. Furthermore, endothelial cells express HSPs in atherosclerosis, and cross-reactive T cells exist in the arteries and peripheral blood of patients with atherosclerosis. It was concluded that although atherosclerotic cardiovascular disease is almost certainly a multifactorial disease, there is now strong evidence that infection and inflammation are important risk factors. As the oral cavity is one potential source of infection, it is wise to try to ensure that any oral disease is minimised. This may be of significant benefit to cardiovascular health and enables members of the oral health team to contribute to their patients' general health.
The main deficit in the majority of the studies on the relation of periodontal disease to cardiovascular conditions has been the inadequate control of numerous confounding factors, and the imprecise measurement of the predictor or over-adjustment of the confounding variables, resulting in underestimation of the risks. A meta-analysis of prospective and retrospective follow-up studies has shown that periodontal disease may increase the risk of CVD by approximately 20% (95% confidence interval [CI], 1.08-1.32).
Similarly, the reported risk ratio between periodontal disease and stroke is even stronger, varying from 2.85 (CI 1.78-4.56) to 1.74 (CI 1.08-2.81). The association between peripheral vascular disease and oral health parameters has been explored in only two studies, and the resultant relative risks among individuals with periodontitis were 1.41 (CI 1.12-1.77) and 2.27 (CI 1.32-3.90), respectively. Overall, it appears that periodontal disease may indeed contribute to the pathogenesis of cardiovascular disease.
Thrombotic thrombocytopenic purpura (TTP) is a rare haematological disease of unknown aetiology. This thrombotic microangiopathy is characterised by microvascular lesions with platelet aggregation. It is found in adults and can be associated with pregnancy, cancer, autoimmune diseases, bone marrow transplantation, drugs and bacterial as well as viral infections. The therapy requires a multi-disciplinary team approach involving dentistry. Even if TTP is immediately treated in an adequate manner, it still shows a mortality of up to 20%. To define a specific treatment concept for periodontal disease and decayed teeth in patients suffering from TTP based on the experiences gained from two cases. The two patient cases revealed a possible association of TTP with dental foci. Because of the severity and mortality of this disease, both prognosis evaluation and treatment standards of periodontologically compromised or decayed teeth have to be strictly followed in patients suffering from TTP. In order to avoid recurrence of TTP, it seems important to remove radically teeth of questionable prognosis.
The term periodontal medicine encompasses the study of the contribution of periodontal infections on several systemic conditions such as atherosclerosis, myocardial infarction, stroke, diabetes, and premature delivery. The early reports of a linkage between periodontitis and systemic conditions are gaining further support from additional epidemiological studies. The evidence continues to suggest that maternal periodontitis may be an important risk factor or risk indicator for pregnancies culminating in preterm low birth-weight deliveries.
Potential mechanisms by which infectious challenge of periodontal origin and systemic inflammation may serve as a potential modifier of parturition are discussed. Furthermore, preliminary data are presented, supporting a hypothetical model in which periodontal pathogens disseminate systemically within the mother and gain access to the foetal compartment.
Several aspects of this hypothetical model remain to be elucidated. Only the clarification of the mechanisms of pathogenesis of both periodontitis and premature deliveries will ultimately allow for accurate diagnoses and successful therapies. The concept of diagnosing and treating a periodontal patient to minimise the deleterious effects of this chronic infectious and inflammatory condition on systemic conditions represents both an unprecedented challenge and opportunity to our profession.
Odontogenic infection sources represent a predisposing risk factor for patients with cardiac valvular disease (CVD) awaiting cardiac valve replacement procedures or for cancer treatment. The incidence and quality of odontogenic infection sources (foci) were evaluated on 152 consecutive patients (study group, SG) undergoing cardiac valve replacement and were compared to 150 age-, gender- and residence-matched non-cardiac patients (control group, CG).
Overall, 218 potential and 116 facultative odontogenic foci were found in 87 (58.3%) and in 79 (51.9%) patients of the SG respectively. In comparison with the CG (48%), the incidence of potential odontogenic infection foci was significantly higher in patients scheduled for aortic valve replacement (AVR) than in those scheduled to undergo mitral valve replacement MVR (70.4% vs. 25.0%, p < 0.01). Additionally, in patients scheduled for AVR, a significantly higher number (p < 0.01) of individual potential dentogenic infection foci (1.7 vs. 0.8 foci/valve) and a higher prevalence of PD (60.2%) was seen than for patients scheduled for MVR (31.8%) or for patients without CVD (1.0 foci/valve; 39.3%; p < 0.05). Cardiologists and cardiac surgeons should play an important role in organising oral rehabilitation of patients scheduled for valve replacement.
In another study, all dental focus examinations related to patients scheduled for heart (valve) surgery and radiotherapy of the head and neck in 16 Dutch hospitals were registered during 3 months. A total number of 470 examinations were performed. Dental foci were found and treated in more than 50% of the patients examined. There was a significant difference between dentate and edentulous patients in the percentage of patients diagnosed and treated for a dental focus. More than 80% of dentate and less than 20% of edentulous patients were treated.
Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation. Anaerobic microbial infections are the most common causes. A study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections. Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10 mCi) of FMISO in 26 nasopharyngeal carcinoma patients and six controls with healthy teeth. Tomograms were interpreted visually to identify hypoxic foci in the jaw. All patients received thorough dental examinations as a pre-radiotherapy work-up.
Fifty-one sites of periodontitis, 15 periodontal abscesses, 14 sites of dental caries with root canal infection, 23 sites of dental caries without root canal infection, and seven necrotic pulps were found by dental examination. Anaerobic pathogens were isolated from 12 patients. Increased uptake of FMISO was found at 45 out of 51 sites of periodontitis, all 15 sites of periodontal abscess, all 14 sites of dental caries with root canal infection, all seven sites of necrotic pulp and 15 sites of dental caries without obvious evidence of active root canal infection. No abnormal uptake was seen in the healthy teeth of patients or in the six controls. The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of FMISO PET scan in detecting odontogenic infections were 93%, 97%, 84%, 99% and 96%, respectively. FMISO PET scan is a sensitive method for the detection of anaerobic odontogenic infections, and may play a complementary role in the evaluation of the dental condition of patients with head and neck tumours prior to radiation therapy.
A dental focus usually is a localised chronic infection that under certain circumstances may result in severe local or systemic disease. The most important dental foci are periodontitis, periapical lesions, advanced carious lesions, non-vital pulp, partially impacted teeth and root tips. Local effects of dental foci particularly are processes that may come to expression because of a compromised immunological defence, such as osteoradionecrosis. Systemic effects are mainly caused by transient bacteraemia which can occur spontaneously out of dental foci or after manipulations such as brushing, flossing and dental treatment. Well known examples are infectious endocarditis, fever during chemotherapy and haematogenous infections of total joint prostheses. For all patients at risk (a.o. endocarditis, endoprosthesis, chemotherapy, radiotherapy) it is important that dental foci are treated. Because in most patients the risk factors are present lifelong, a healthy dentition and a healthy periodontium are the best way of prevention.
Infections of the deep neck spaces with accompanying mediastinitis are still a therapeutic problem with a high mortality. A study reported on three patients with deep neck space infections and accompanying mediastinitis who had been treated in the Departments of Otorhinolaryngology at the Universities of Bochum and Essen in the past 2 years. In two patients the infection originated from a peritonsillar abscess and in one patient from an odontogenic infection. One patient was successfully treated by a tonsillectomy and drainage of the parapharyngeal abscess in conjunction with a thoracotomy because of a mediastinal abscess and bilateral pneumothorax. The second patient was cured by a tonsillectomy, wide cervical drainage und cervical mediastinotomy.
A study reported two cases of septic pulmonary embolism associated with periodontitis. Both patients had toothache, fever, and chest pain, and showed findings of periodontitis at initial presentation. Antimicrobial agents combined with dental surgery were successful in treatment. While septic pulmonary embolism from the lesions of periodontitis appears to be rare, periodontitis remains important in the differential diagnosis of septic pulmonary embolism.
One study found a positive correlation between higher levels of periodontal disease and various types of rheumatic conditions, as well as with various alterations of saliva flow, including slower flow rates and higher levels of immune reactivity. This was consistent with autoimmunity commonly found in some of these rheumatic conditions.
Odontogenic sinusitis is a well-recognised condition and accounts for approximately 10% to 12% of cases of maxillary sinusitis. An odontogenic source should be considered in individuals with symptoms of maxillary sinusitis with a history of odontogenic infection, dentoalveolar surgery, periodontal surgery, or in those resistant to conventional sinusitis therapy. Diagnosis usually requires a thorough dental and clinical evaluation including appropriate radiographs. The most common causes of odontogenic sinusitis include dental abscesses and periodontal disease that had perforated the Schneidarian membrane, irritation and secondary infection caused by intra-antral foreign bodies, and sinus perforations during tooth extraction.
An odontogenic infection is a polymicrobial aerobic-anaerobic infection, with anaerobes outnumbering the aerobes. The most common isolates include anaerobic streptococci and gram-negative bacilli, and Enterobacteriaceae. Surgical and dental treatment of the odontogenic pathological conditions combined with medical therapy is indicated. When present, an odontogenic foreign body should be surgical removed. Although odontogenic sinusitis is a rare entity when compared to sinus disease of rhinogenic origin, it is extremely important to identify a dental aetiology when it occurs. The offending tooth or teeth would thus require endodontic treatment or extraction, and the sinus disease carefully assessed and appropriately managed. Certain lesions such as cysts and tumours may involve the jaws and hence the maxillary antrum; some of these, such as a radicular cyst are quite common.
Another study presented a case of periapical infection resulting in unilateral maxillary sinusitis and cellulitis of the ipsilateral lower eyelid. while another provided a case of a pathogenic fungus infecting the sinus related to a dental infectious source. This pathogenic fungus is very invasive, particularly in immuno-depressed or immuno-compromised patients.
Movement disorders – or dyskinesias – are characterised by involuntary movements. A review found a significant association between dental conditions and some common dyskinesias, viz., Gilles de la Tourette's syndrome, Huntington's disease, idiopathic torsion dystonia, oral dyskinesias, and Parkinson's disease. Generalised dyskinesias were found to have focal manifestations in the orofacial region.
The association of alopecia areata and infectious foci of dental origin is relatively common, and may be explained by the autoimmune nature of the disorder. A study described a case of alopecia areata with no apparent cause and that was effectively resolved by eliminating a focalised dental infection via endodontic treatment. The presence of common immune mediators in the pathogenesis of both alopecia areata and dental infection could account for the dental origin of the hair loss. In this sense, patients with localised alopecia should be subjected to careful exploration of the oral cavity in search of possible dental infections.
II. Health Effects Related to Root Canals
Studies have found that all root-canalled teeth with asymptomatic apical periodontitis contain anaerobic bacteria and are a significant source of bacteria and fungi in the circulating blood, and thus a potential source of systemic focal infections. One study used phenotypic and genetic methods to trace microorganisms released into the bloodstream during and after endodontic treatment back to their presumed source – the root canal. Microbiological samples were taken from the root canals of 26 patients with asymptomatic apical periodontitis of single-rooted teeth. The blood of the patients was drawn during and 10 minutes after endodontic therapy. All root canals contained anaerobic bacteria. The frequency of bacteraemia varied from 31% to 54%. The microorganisms from the root canal and blood presented identical phenotype and genetic characteristics within the patients examined.
The study demonstrated that endodontic treatment can be the cause of anaerobic bacteraemia and fungaemia. In another study quantitation of circulating immune complexes (CIC) was done in 45 patients with chronic periapical lesions. The levels were compared with those of age-matched healthy individuals. Both patients with chronic periapical granuloma and periapical cysts showed significantly higher levels of CIC than the controls. This observation indicates that the continuous presence of root canal antigens may cause elevated levels of circulating immune complexes. The possibility of chronic periapical lesions acting as foci of infection is discussed, and the importance of early treatment of these conditions is emphasised ... (continued - see below)
"Alison, I salute you for this excellent book. As a fellow practitioner, I applaud your passion, tenacity and unerring dedication to share with others what you so painfully have undertaken for your own health, and painstakingly researched and recorded for others to benefit from."
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