Are dental diseases examples of ecological catastrophes?

Dental diseases are among the most prevalent and costly diseases affecting industrialized societies, and yet are highly preventable. The microflora of dental plaque biofilms from diseased sites is distinct from that found in health, although the putative pathogens can often be detected in low numbers at normal sites. In dental caries, there is a shift towards community dominance by acidogenic and acid-tolerant Gram-positive bacteria (e.g. mutans streptococci and lactobacilli) at the expense of the acid-sensitive species associated with sound enamel. In contrast, the numbers and proportions of obligately anaerobic bacteria, including Gram-negative proteolytic species, increase in periodontal diseases. Modelling studies using defined consortia of oral bacteria grown in planktonic and biofilm systems have been undertaken to identify environmental factors responsible for driving these deleterious shifts in the plaque microflora. Repeated conditions of low pH (rather than sugar availability per se) selected for mutans streptococci and lactobacilli, while the introduction of novel host proteins and glycoproteins (as occurs during the inflammatory response to plaque), and the concomitant rise in local pH, enriched for Gram-negative anaerobic and asaccharolytic species. These studies emphasized (a). significant properties of dental plaque as both a biofilm and a microbial community, and (b). the dynamic relationship existing between the environment and the composition of the oral microflora. This research resulted in a novel hypothesis (the 'ecological plaque hypothesis') to better describe the relationship between plaque bacteria and the host in health and disease. Implicit in this hypothesis is the concept that disease can be prevented not only by directly inhibiting the putative pathogens, but also by interfering with the environmental factors driving the selection and enrichment of these bacteria. Thus, a more holistic approach can be taken in disease control and management strategies.

Orofacial odontogenic infections

Clinical manifestations of odontogenic orofacial infections are protean and are largely dictated by complex microbiota and anatomic routes of spread. Complications such as suppurative mediastinal or intracranial extension, retropharyngeal spread and airway obstruction, pleuropulmonary involvement, and hematogenous dissemination indicate the potentially serious nature of these infections. In this review we emphasize the pathogenetic mechanisms of infection, the principles of antimicrobial therapy, and the need for early surgical intervention.

Severe odontogenic infections, part 1: prospective report

PURPOSE

The purpose of this study was to prospectively evaluate a series of patients with severe odontogenic infections (OI).

PATIENTS AND METHODS

In this study, 37 consecutive hospitalized patients with odontogenic infection were treated with intravenous penicillin (PCN) (unless allergic), and prompt incision and drainage. Standardized data collection included demographic, preadmission, time-related, preoperative, anatomic, treatment, microbiologic, and complications information. Appropriate descriptive statistics were computed.

RESULTS

The sample consisted of 37 subjects (38% female) with a mean age of 34.9 years. Three subjects (8%) had immunocompromising diseases. Caries was the most frequent dental disease (65%) and the lower third molar was the most frequently involved tooth (68%). Trismus and dysphagia were present on admission in over 70% of cases. The masticator, perimandibular (submandibular, submental, and/or sublingual), and peripharyngeal (lateral pharyngeal, retropharyngeal, and/or pretracheal) spaces were infected in 78%, 60%, and 43% of cases, respectively. Abscess was found in 76% of cases. PCN-resistant organisms were identified in 19% of all strains isolated and in 54% of patients with sensitivity data. PCN therapeutic failure occurred in 21% of cases and reoperation was required in 8%. Length of hospital stay was 5.1 +/- 3.0 days. No deaths occurred.

CONCLUSIONS

This study indicated that PCN resistance, resulting in PCN therapeutic failure, was unacceptably high in this sample. Alternative antibiotics, such as clindamycin, should be considered in hospitalized patients with OI. Masticator space infection occurred much more frequently than previously reported. Trismus and dysphagia should be appreciated as significant indicators of severe OI.

The division "Synergistes"

The "Synergistes" group of organisms are a phylogenetic cluster of Gram-negative anaerobes related to Synergistes jonesii, sufficiently distinct from all other phyla to be considered a distinct phylum or Division. They are widely distributed in nature although normally only a minor constituent of the bacterial community in each habitat. They have evolved to adapt to each habitat, and therefore exhibit a wide range of physiological and biochemical characteristics, although all cultivable taxa so far studied have the ability to degrade amino acids. They are found in the human mouth where they appear to be more numerous in tooth and gum disease than health. They have also been found in the human gut and soft tissue infections. Their role in human disease has yet to be established but improved knowledge of the characteristics that enable their identification should increase the likelihood of their recognition when present at diseased sites.

Severe odontogenic infections, part 2: prospective outcomes study

PURPOSE

The purpose of this study was to identify significant predictors of 4 outcomes in patients with severe odontogenic infections: abscess formation, penicillin therapeutic failure (PTF), length of hospital stay (LOS), and need for reoperation.

PATIENTS AND METHODS

We used a prospective case series study design and enrolled 37 consecutive patients admitted for severe odontogenic infection between March 1996 and June 1999. Treatment consisted of intravenous penicillin (PCN) or clindamycin in PCN-allergic patients, surgical incision and drainage, and extraction(s) as soon as possible. Study variables were categorized as demographic, preadmission, time-related, preoperative, anatomic, treatment, microbiologic, and complications. The primary outcome variables were abscess formation, PTF, LOS, and reoperation. Multivariate linear and logistic regression techniques were used to measure associations between study variables and the outcome variables.

RESULTS

The sample consisted of 37 subjects (23 male, 14 female) with a mean age of 34.9 +/- 15.8 years. Multivariate analyses, controlling for confounding variables, indicated that culture of Peptostreptococci was a negative predictor of abscess formation. LOS was predicted by the number of infected spaces and duration of operation. There was no significant predictor of PTF or reoperation on multivariate analysis, although PCN-resistant organisms were isolated in all cases of PTF.

CONCLUSION

Increased LOS in severe odontogenic infections is predicted by the anatomic extent and severity of the infection and the occurrence of complications such as PTF and the need for reoperation. PTF is significantly associated with later identification of PCN-resistant organisms. The role of Peptostreptococci in abscess formation warrants further investigation.

Microbiology of acute and chronic maxillary sinusitis associated with an odontogenic origin

OBJECTIVES

: To study the microbiology of sinusitis associated with odontogenic origin.

METHODS

: Aspirates of 20 acutely and 28 chronically infected maxillary sinuses that were associated with odontogenic infection were processed for aerobic and anaerobic bacteria.

RESULTS

: A total of 66 isolates were recovered from the 20 cases of acute sinusitis (3.3/specimen), 16 aerobic and facultatives, and 50 anaerobic. Aerobes alone were recovered in 2 (10%) specimens, anaerobes only in 10 (50%), and mixed aerobic and anaerobic bacteria in 8 (40%). The predominant aerobic were alpha-hemolytic streptococci (5), microaerophilic streptococci (4), and Staphylococcus aureus (2). The predominant anaerobes were anaerobic Gram-negative bacilli (22), Peptostreptococcus (12), and Fusobacterium spp. (9). A total of 98 isolates were recovered from the 28 cases of chronic sinusitis (3.5/patient): 21 aerobic and facultatives and 77 anaerobic. Aerobes were recovered in 3 (11%) instances, anaerobes only in 11 (39%), and mixed aerobic and anaerobic bacteria in 14 (50%). The predominant aerobes were alpha-hemolytic streptococci (7), microaerophilic streptococci (4), and S. aureus (5). The predominant anaerobes were Gram-negative bacilli (41), Peptostreptococcus (16), and Fusobacterium spp. (12). Thirteen beta-lactamase-producing bacteria (BLPB) were recovered from 10 (50%) patients with acute sinusitis and 25 BLPB from 21 (75%) patients with chronic sinusitis. No correlation was found between the predisposing odontogenic conditions and the microbiological findings.

CONCLUSIONS

: These data illustrate the similar microbiology of acute and chronic maxillary sinusitis associated with odontogenic infection where anaerobic bacteria predominate in both types of infections.

Cervical necrotizing fasciitis: clinical manifestations and management

Forty-five cases of cervical necrotizing fasciitis are reported, and their clinical, bacteriologic, and therapeutic implications are considered. Fasciitis was of dental origin in 78% of cases, pharyngeal in 16%, and surgical or posttraumatic in 6%. The condition extended to the face in 22% of cases, to the lower part of the neck in 56%, and to the mediastinum in 40%. Soft-tissue cultures were positive in 78% of cases. Anaerobes were isolated along with aerobes in 49% of cases (mean, 2.2 isolates per patient) and in pure culture in 22%. Treatment included surgical debridement and drainage and the administration of antibiotics active against both anaerobic and gram-negative aerobic bacteria. Hyperbaric oxygen was used for adjunctive treatment. The bacteria involved did not affect clinical manifestations, extension, or mortality. The survival rate among our patients was 78%. Mortality was significantly higher among cases with mediastinal extension (44% vs. 7%; P < .01); thus the prompt recognition and drainage of sites of mediastinal extension are of critical importance. Other risk factors for death were an age of > 70 years, underlying diabetes, the development of septic shock within 24 hours after admission, and prolonged prothrombin time.

Bacterial study of pyogenic infections of dental origin

Fluctuant abscesses of dental origin were sampled by syringe aspiration. These samples were cultured by means of techniques suitable for isolation and growth of obligate anaerobes. Oral abscesses are usually mixed infections that include a number of different species. More than 65 per cent of the species isolated were obligate anaerobes, which indicates the need for anaerobic methods in studying these infections. Anaerobic gram-negative rods and facultative streptococci were the groups isolated most frequently.

Clinical appearance of orofacial infections of odontogenic origin in relation to microbiological findings

Fifty-eight patients with acute orofacial infections of odontogenic origin were classified into two groups with respect to the severity of infection. A total of 174 anaerobic and 22 aerobic bacterial strains were isolated. Anaerobic gram-negative rods were isolated more frequently from the patients with severe infections than from the patients with infections judged as mild (P less than 0.05). The occurrence of Fusobacterium nucleatum especially appeared to be associated with the severity of the infections (P less than 0.05). Penicillin resistance among the anaerobes was rarely found, while resistance to erythromycin was a common finding. All aerobic and anaerobic bacteria were susceptible to clindamycin, and all obligate anaerobic bacteria were susceptible to nitroimidazoles.

Bacteriology and treatment of dental infections

The microbiologic and therapeutic aspects of sixty-one cases of pyogenic dental infection were studied through the use of modern anaerobic culture methods. Forty-five (74 percent) patients had anaerobic infections. Among them, eighteen (29.5 percent) had Bacteroides fragilis, of which six were resistant to penicillin at 16 microgram/ml. but all were susceptible to clindamycin at less than 2 microgram/ml. Of twenty-five patients treated with 4 to 20 million units of penicillin per day, twenty were cured and did not suffer relapse. The five patients in whom treatment failed had mandibular fractures infected with B. fragilis. Of ten patients treated with clindamycin (600 mg. intravenously every 6 hours), which included five patients with B. fragilis infections, all were cured. The presence of B. fragilis in dental infections has not been recognized. Dental infections associated with mandibular fracture that fail to respond to conventional penicillin therapy should be routinely cultured for B. fragilis.

Oral microbiology: past, present and future

Since the initial observations of oral bacteria within dental plaque by van Leeuwenhoek using his primitive microscopes in 1680, an event that is generally recognized as the advent of oral microbiological investigation, oral microbiology has gone through phases of "reductionism" and "holism". From the small beginnings of the Miller and Black period, in which microbiologists followed Koch's postulates, took the reductionist approach to try to study the complex oral microbial community by analyzing individual species; to the modern era when oral researchers embrace "holism" or "system thinking", adopt new concepts such as interspecies interaction, microbial community, biofilms, poly-microbial diseases, oral microbiological knowledge has burgeoned and our ability to identify the resident organisms in dental plaque and decipher the interactions between key components has rapidly increased, such knowledge has greatly changed our view of the oral microbial flora, provided invaluable insight into the etiology of dental and periodontal diseases, opened the door to new approaches and techniques for developing new therapeutic and preventive tools for combating oral polymicrobial diseases.

Oral health in children with chronic renal failure

Seventy children with chronic renal failure (CRF) aged 4-13.6 years were recruited from the Renal Unit of the Great Ormond Street Hospital for Children. Indices were recorded for dental caries, dental plaque, gingival inflammation, gingival enlargement, and enamel defects. Salivary urea, buffering capacity, and the oral streptococcal flora were determined for 25 of the children. A significantly greater proportion of the CRF children was caries free, 40% compared with 8.5% of the controls. The mean plaque score was significantly greater in the CRF group for both the primary 12.7 (16) and permanent dentition 22.0 (18.2) compared with the controls, 5.3 (7.6) and 15.5 (13.3), respectively. Eight CRF children had gingival enlargement. Enamel defects affecting the permanent teeth were observed in 57% of the CRF children compared with 33% of the controls. The buffering capacity was significantly greater in the CRF group, pH 6.4 (0.5) compared with the controls pH 5.6 (0.8). The mean salivary urea level (mmol/l) was significantly greater in the CRF children, 11.6 (5.9) compared with 3.6 (1.4) for the controls. The isolation frequency of Streptococcus mutans was significantly greater from controls compared with the CRF children ( P=0.002). An integrated dental service needs to be developed with emphasis on tooth brushing to prevent gingival hyperplasia and periodontal disease after puberty.

Identification and localization of extraradicular biofilm-forming bacteria associated with refractory endodontic pathogens

Bacterial biofilms have been found to develop on root surfaces outside the apical foramen and be associated with refractory periapical periodontitis. However, it is unknown which bacterial species form extraradicular biofilms. The present study aimed to investigate the identity and localization of bacteria in human extraradicular biofilms. Twenty extraradicular biofilms, used to identify bacteria using a PCR-based 16S rRNA gene assay, and seven root-tips, used to observe immunohistochemical localization of three selected bacterial species, were taken from 27 patients with refractory periapical periodontitis. Bacterial DNA was detected from 14 of the 20 samples, and 113 bacterial species were isolated. Fusobacterium nucleatum (14 of 14), Porphyromonas gingivalis (12 of 14), and Tannellera forsythensis (8 of 14) were frequently detected. Unidentified and uncultured bacterial DNA was also detected in 11 of the 14 samples in which DNA was detected. In the biofilms, P. gingivalis was immunohistochemically detected in all parts of the extraradicular biofilms. Positive reactions to anti-F. nucleatum and anti-T. forsythensis sera were found at specific portions of the biofilm. These findings suggested that P. gingivalis, T. forsythensis, and F. nucleatum were associated with extraradicular biofilm formation and refractory periapical periodontitis.

Craniocervical necrotizing fasciitis: an 11-year experience

OBJECTIVE

We review our experience and present our approach to treating craniocervical necrotizing fasciitis (CCNF).

STUDY DESIGN

All cases of CCNF treated at Wayne State University/Detroit Receiving Hospital from January 1989 to April 2000 were reviewed. Patients were analyzed for source and extent of infection, microbiology, co-morbidities, antimicrobial therapy, hospital days, surgical interventions, complications, and outcomes.

RESULTS

A review of 250 charts identified 10 cases that met the study criteria. Five cases (50%) had spread of infection into the thorax, with only 1 (10%) fatality. An average of 24 hospital days (7 to 45), 14 ICU days (6 to 21), and 3 surgical procedures (1 to 6) per patient was required.

CONCLUSION

Aggressive wound care, broad-spectrum antibiotics, and multiple surgical interventions resulted in a 90% (9/10) overall survival and 80% (4/5) survival for those with thoracic extension.

SIGNIFICANCE

This is the largest single institution report of CCNF with thoracic extension identified to date.

Acute dentoalveolar infections: an investigation of the duration of antibiotic therapy

OBJECTIVE

To evaluate shortened courses of antibiotics in the management of dentoalveolar abscesses.

DESIGN

Prospective clinical study over a 3-year period.

SETTING

Examinations department of the Liverpool University Dental Hospital.

SUBJECTS

759 patients, with acute dentoalveolar abscesses associated with swelling, and an elevation of axillary temperature to above 38.5 degrees C, were included in the investigation. The minimum age of the patients was 16 years.

INTERVENTIONS

The initial treatment was to drain the abscess by incision (124 patients), or extraction (635). The patients were prescribed amoxycillin (250 mg every 8 hours), clindamycin (150 mg every 6 hours) or erythromycin stearate (250 mg every 6 hours) and instructed to drink plenty of fluid. All the patients were seen 2 or 3 and 10 days later; only patients who were seen at these times were included in the trial.

MAIN OUTCOME MEASURES

Resolution of the swelling and a normal axillary temperature.

RESULTS

At first review 748 patients (98.6%) had normal temperatures, marked resolution of the swelling and the antibiotic was discontinued. None of these 748 patients required further antibiotic therapy.

CONCLUSIONS

The duration of antibiotic therapy in most patients with acute dentoalveolar infections can safely be 2-3 days, provided that drainage has been established. It is not, therefore, necessary for the majority of patients to complete a 5-day course of antibiotics.

The importance of apical patency and cleaning of the apical foramen on root canal preparation

The apical limit of root canal instrumentation has always been a matter of great controversy. Despite the large number of published studies on this subject, a consensus has not yet been reached. In fact, the recent discussion on apical patency and cleaning of the apical foramen, as well as the incorporation of these procedures to the endodontic treatment, seem to have raised even more polemics. It is likely that all this polemics has its roots in the lack of interrelation between the theoretical knowledge of pulp stump and periapical tissues and the real clinical practice. By addressing the most important aspects of this theme, this paper aims to present news concepts about the importance of apical patency and cleaning of the apical foramen during root canal preparation.

Antibiotic therapy--managing odontogenic infections

Several pharmaceuticals have been developed in the past 10 years that have made a significant impact on the health of the human race. There have been few advances, however, that have proved more efficacious than the pharmacotherapies we have had available for many decades for the treatment of odontogenic infections. Many new antibiotics/antimicrobials have been developed, but none have been determined to be of significant benefit to replace or supplant the use of penicillins for the management of orofacial infections caused by pathogens in and around the oral cavity. Judicious use of antibiotics in conjunction with surgical therapy is the most appropriate method to treat odontogenic infections. Using the antibiotic "du jour," many times promoted by pharmaceutical representatives, results in costly and unnecessary complexity of care. A return to the basics is indicated for the antibiotic management of odontogenic infections.

Location of Streptococcus mutans in the dentinal tubules of open infected root canals

Seventy-six teeth from open canals were extracted to prepare serial longitudinal sections. The sections were made from apical portions of the teeth and stained. Ninety similar teeth were extracted to prepare dentinal splinters with files from the enlarged infected canal. The splinters were spread on a selected medium to grow S. mutans. S. mutans was detected in 48.7% of the 76 teeth examined. The distance of invasion of S. mutans in the dentinal tubules revealed by immunofluorescence averaged 509 micrometer from the canal wall and reached 1150 micrometer, depending on the serogroups of S. mutans. Unidentified germs in the sections which were demonstrated by Gram's stain invaded further than S. mutans. The frequency of appearance of the serogroups of S. mutans was 32.6% (d), 27.9% (c), 24.4% (a), and 15.5% (b).

A prospective double-blind evaluation of penicillin versus clindamycin in the treatment of odontogenic infections

In a prospective, double-blind trial, penicillin and clindamycin were compared in treatment of moderate to severe orofacial infections of odontogenic origin, which yielded pus on aspiration. Among 27 patients randomized to receive penicillin, 22 (81%) had a successful outcome, and five (19%) were improved. In the 28 clindamycin-treated patients, 23 (82%) had a successful outcome, and five (18%) were improved. No failures were noted in either group. One patient who was receiving penicillin and two who were receiving clindamycin developed diarrhea. Bacteriologic results showed an average of 6.1 organisms per culture (2.5 aerobes and 3.6 anaerobes). Resistance rates for anaerobic isolates were 8.9% to penicillin and 1.9% to clindamycin. It was concluded that penicillin and clindamycin produce similar good results in treating odontogenic infection when the rate of penicillin resistance among oral anaerobic bacteria is at a relatively low level.

Indications of antibiotic prophylaxis in dental practice- review

Antibiotics are frequently used in dental practice. Clinical and bacteriological epidemiological factors determine the indications of antibiotics in dentistry. Antibiotics are used in addition to appropriate treatment to aid the host defences in the elimination of remaining bacteria. It is indicated when there is evidence of clinical sign involvement and spread of infection. Antibiotics are prescribed in dental practice for treating odontoge nic infections, non-odontogenic infections, as prophylaxis against focal and local infection. Special care needs to be addressed to patients with organ transplants, poorly controlled diabetes and pregnancy. Antibiotics should be used only as an adjunct to dental treatment and never alone as the first line of care. The present paper reviews the indications of antibiotics in dental practice.

Association of CD14, IL1B, IL6, IL10 and TNFA functional gene polymorphisms with symptomatic dental abscesses

AIM

To investigate in individuals with symptomatic dental abscesses the occurrence of functional polymorphisms within five genes involved with the immune response. The functional gene polymorphisms analysed were CD14 (-260 C/T), IL1B (+3954 C/T), IL6 (-174 G/C,), IL10 (-1082 G/A) and TNFA (-308 G/A).

METHODOLOGY

Genomic DNA obtained from oral swabs from individuals with symptomatic dental abscesses and asymptomatic inflammatory periapical lesions, without previous exacerbation, was submitted to restriction fragment length polymorphism (RFLP) analyses to determine each individual genotype. The chi-square and principal components analysis tests were used for statistical analysis.

RESULTS

A significant association was observed between the occurrence of the GG genotype or the G allele expression of the polymorphic locus-174 (G/C) of the IL6 gene, and the presence of the symptomatic dental abscesses in women and in individuals < or =35 years old. The principal components analysis suggested predominance of the symptomatic dental abscesses in individuals displaying: high-producer IL6 genotype; intermediate and high-producer IL1B genotypes and low-producer TNFA genotype.

CONCLUSIONS

The present study suggests that genetic factors are associated with susceptibility to develop symptomatic dental abscesses.

Bacteriology and antimicrobial susceptibility of gram-positive cocci isolated from pus specimens of orofacial odontogenic infections

We recently reported the beta-lactamase production and antimicrobial susceptibility of anaerobic gram-negative rods isolated from pus specimens of 93 orofacial odontogenic infections. In this report, we determine the bacteriology and antimicrobial susceptibility of bacteria other than anaerobic gram-negative rods, mainly gram-positive cocci, isolated from the same specimens. Streptococcus constellatus and Peptostreptococcus micros were frequent isolates from all types of infection examined. Peptostreptococcus prevotii, Corynebacterium species, and Eubacterium species were recovered only from dentoalveolar infections, while Gemella morbillorum was found more frequently in periodontitis than in the other infections. beta-Lactamase-positive strains were detected only in staphylococci. Ampicillin, ampicillin/sulbactam, cefazolin, cefotaxime, imipenem, erythromycin, clindamycin and levofloxacin showed high susceptibility rates (> or = 77%) against viridans streptococci, Peptostreptococcus and Gemella. Minocycline showed a high MIC90 value against viridans streptococci (32 microg/ml), and metronidazole was effective against Peptostreptococcus and Gemella. These results provide useful information for the treatment of orofacial odontogenic infections.