Rediscovering Sig Socransky, the genius and his legacy.

Some individuals make contributions so vital to their field of knowledge that their names become almost synonymous with that field. This is the case of Sig Socransky and the field of periodontal microbiology. Sig Socransky, or simply Sig, was born in Toronto, Canada and received his DDS degree from the University of Toronto in 1957. He studied microbiology and periodontology at Harvard, receiving a certificate in 1961. That same year he was recruited to work as a Research Associate at the Forsyth Dental Center. In 1968, he was nominated Senior Member of the Staff and Head of the Department of Periodontology. During his 50-year career at Forsyth, Sig published over 300 manuscripts, keeping an average of 7 publications per year. His work had an indelible impact in the fields of periodontology and oral microbiology. All these accomplishments pale in comparison with the impact that Sig had on a personal level. We have collected testimonials from some of his former students, closest collaborators, and friends in an attempt to give readers an insight into Sig's personality. We hope we can offer those who knew him through his work a glimpse of how it felt to interact with this remarkable individual.

The diagnosis of periodontal disease in private practice.

BACKGROUND: Periodontal disease is an inflammatory reaction to the bacteria in dental plaque. The present study compared the prevalence of periodontal disease in patients using as a diagnostic either probing depth measurements, an inflammatory marker such as numbers of white blood cells in plaque samples, or microbiological markers such as the microscopic count and the benzoyl-DL-arginine naphthylamide (BANA) test. METHODS: Teeth with the most inflammation and/or deepest pockets in each quadrant were probed and subgingival plaque was sampled from 1,043 consecutive new patients enrolled in a private practice. Multivariate "diagnostic" models were developed based upon the probing depth (general linear models), percentage of white blood cell-positive and percentage of BANA-positive plaques (logistic regression models) to determine the prevalence of patients with periodontal disease. RESULTS: Plaque samples were removed from 3,694 sites. Fifty-two percent of sampled pockets were >4 mm; 49% of sites were inflamed, using the presence of white blood cells, and 28% were infected using the BANA test. Diagnostic models were highly significant at P<0.0001. The white blood cell model was the most parsimonious as demonstrated by the lowest Akaike information criteria statistic and had the highest receiver operator characteristic (ROC) curve relative to the probing depth and BANA models. CONCLUSIONS: Periodontal disease can be diagnosed chairside by the presence of white blood cells in plaque samples, a finding that reflects the inflammatory nature of the disease process. This approach would reduce the misclassification of subjects as having periodontal disease (130 patients in the present study who had pockets) but minimal evidence of an inflammatory response.

Dental flossing and interproximal caries: a systematic review.

Our aim was to assess, systematically, the effect of flossing on interproximal caries risk. Six trials involving 808 subjects, ages 4 to 13 years, were identified. There were significant study-to-study differences and a moderate to large potential for bias. Professional flossing performed on school days for 1.7 years on predominantly primary teeth in children was associated with a 40% caries risk reduction (relative risk, 0.60; 95% confidence interval, 0.48-0.76; p-value, < 0.001). Both three-monthly professional flossing for 3 years (relative risk, 0.93; 95% confidence interval, 0.73-1.19; p-value, 0.32) and self-performed flossing in young adolescents for 2 years (relative risk, 1.01; 95% confidence interval, 0.85-1.20; p-value, 0.93) did not reduce caries risk. No flossing trials in adults or under unsupervised conditions could be identified. Professional flossing in children with low fluoride exposures is highly effective in reducing interproximal caries risk. These findings should be extrapolated to more typical floss-users with care, since self-flossing has failed to show an effect.

The transmission of anaerobic periodontopathic organisms.

The oral microbial flora is unique, and available evidence indicates that it is passed vertically from parents to children. In this investigation, we used a chairside assay for the N-benzoyl-DL-arginine-2-naphthylamide (BANA)-sensitive enzyme found in Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythensis, to determine the prevalence of these BANA-positive species in young children and their caregivers. We predicted that if the BANA enzyme was found in plaque samples of children, it would also be present in the plaque samples of the caregivers. Forty-four percent of 150 children had at least one plaque sample positive for the BANA enzyme. If the caregiver was BANA-positive, the odds of the child also being BANA-positive was 35 times more than for a child with a BANA-negative caregiver, after adjustment for the child's age and papillary bleeding score (PBS). Other significant predictors were the PBS of children (p < 0.001), a history of periodontal disease, and the ages of the caregivers (p < 0.001).

Diversity of bacterial populations on the tongue dorsa of patients with halitosis and healthy patients.

The primary purpose of the present study was to compare the microbial profiles of the tongue dorsa of healthy subjects and subjects with halitosis by using culture-independent molecular methods. Our overall goal was to determine the bacterial diversity on the surface of the tongue dorsum as part of our ongoing efforts to identify all cultivable and not-yet-cultivated species of the oral cavity. Tongue dorsum scrapings were analyzed from healthy subjects with no complaints of halitosis and subjects with halitosis, defined as an organoleptic score of 2 or more and volatile sulfur compound levels greater than 200 ppb. 16S rRNA genes from DNA isolated from tongue dorsum scrapings were amplified by PCR with universally conserved bacterial primers and cloned into Escherichia coli. Typically, 50 to 100 clones were analyzed from each subject. Fifty-one strains isolated from the tongue dorsa of healthy subjects were also analyzed. Partial sequences of approximately 500 bases of cloned inserts from the 16S rRNA genes of isolates were compared with sequences of known species or phylotypes to determine species identity or closest relatives. Nearly complete sequences of about 1,500 bases were obtained for potentially novel species or phylotypes. In an analysis of approximately 750 clones, 92 different bacterial species were identified. About half of the clones were identified as phylotypes, of which 29 were novel to the tongue microbiota. Fifty-one of the 92 species or phylotypes were detected in more than one subject. Those species most associated with healthy subjects were Streptococcus salivarius, Rothia mucilaginosa, and an uncharacterized species of Eubacterium (strain FTB41). Streptococcus salivarius was the predominant species in healthy subjects, as it represented 12 to 40% of the total clones analyzed from each healthy subject. Overall, the predominant microbiota on the tongue dorsa of healthy subjects was different from that on the tongue dorsa of subjects with halitosis. Those species most associated with halitosis were Atopobium parvulum, a phylotype (clone BS095) of Dialister, Eubacterium sulci, a phylotype (clone DR034) of the uncultivated phylum TM7, Solobacterium moorei, and a phylotype (clone BW009) of STREPTOCOCCUS: On the basis of our ongoing efforts to obtain full 16S rRNA sequences for all cultivable and not-yet-cultivated species that colonize the oral cavity, there are now over 600 species.

Periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment.

Periodontal disease is perhaps the most common chronic infection in adults. Evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola. The success of traditional debridement procedures and/or antimicrobial agents in improving periodontal health can be associated with the reduction in levels of these anaerobes in the dental plaque. These findings suggest that patients and clinicians have a choice in the treatment of this overgrowth, either a debridement and surgery approach or a debridement and antimicrobial treatment approach. However, the antimicrobial approach, while supported by a wealth of scientific evidence, goes contrary to centuries of dental teaching that states that periodontal disease results from a "dirty mouth." If periodontal disease is demonstrated to be a risk factor for cardiovascular disease and stroke, it will be a modifiable risk factor since periodontal disease can be prevented and treated. Since the antimicrobial approach may be as effective as a surgical approach in the restoration and maintenance of a periodontally healthy dentition, this would give a cardiac or stroke patient and his or her physician a choice in the implementation of treatment seeking to improve the patient's periodontal condition so as to reduce and/or delay future cardiovascular events.

Aspiration pneumonia: dental and oral risk factors in an older veteran population.

OBJECTIVES: To investigate the importance of medical and dental factors in aspiration pneumonia in an older veteran population. DESIGN: Prospective enrollment of subjects with retrospective analysis of data. SETTING: Department of Veterans Affairs outpatient clinic, inpatient ward, and nursing home. PARTICIPANTS: 358 veterans age 55 and older; 50 subjects with aspiration pneumonia. MEASUREMENTS: Demographic and medical data; functional status; health-related behaviors; dental care utilization; personal oral hygiene; comprehensive dental examination; salivary assays including IgA antibodies; and cultures of saliva, throat, and dental plaques. RESULTS: Two logistic regression models produced estimates of significant risk factors. One model using dentate patients included: requiring help with feeding (odds ratio (OR) = 13.9), chronic obstructive pulmonary disease (COPD) (OR = 4.7), diabetes mellitus (OR = 3.5), number of decayed teeth (OR = 1.2), number of functional dental units (OR = 1.2), presence of important organisms for decay, Streptococcus sobrinus in saliva (OR = 6.2), and periodontal disease, Porphyromonous gingivalis in dental plaque (OR = 4.2), and Staphylococcus aureus presence in saliva (OR = 7.4). The second model, containing both dentate and edentulous patients included: requiring help with feeding (OR = 4.7), COPD (OR = 2.5), diabetes mellitus (OR = 1.7), and presence of S. aureus in saliva (OR = 8.3). CONCLUSION: This study supports the significance of oral and dental factors while controlling for established medical risk factors in aspiration pneumonia incidence.

Minor salivary gland secretion in the elderly.

OBJECTIVE: Very little information exists on minor salivary gland output (MSGO) in health and disease. We investigated the minor salivary gland output of elderly subjects with different medical backgrounds and the relationship of that output with life practices, demographic variables, complaints of dry mouth, medication usage, functional status, medical treatments, and dental and medical variables. STUDY DESIGN: MSGO was measured with a special moisture-detecting paper on the lip, cheek, and palate, which comprised the total MSGO. A parsimonious linear regression model was developed to determine which of the many measured variables influenced the MSGO. RESULTS: There were significant differences in MSGO between the recruitment sites, with the non-Veteran Affairs (VA) Independent Living participants having significantly lower MSGO than the VA groups. A secretion rate for MSGO based on median values from all subjects of <4.6 microL/min was categorized as being low, whereas a secretion rate for MSGO >/=4.6 microL/min was categorized as high. A regression model was used to examine variables that could be associated with MSGO variability. The results show that being older, a woman, a current smoker, and having a complaint of dry mouth were associated with lower MSGO rates. CONCLUSIONS: An association between subjective complaints of dry mouth and a decrease in MSGO measured objectively was demonstrated in this elderly population. Furthermore, age and sex effects on MSGO were also demonstrated.

Periodontal disease: link to cardiovascular disease.

Poor oral hygiene that leads to dental infections could contribute to adverse medical outcomes such as cardiovascular disease. Twelve studies of varying degrees of design rigor have associated dental conditions, such as periodontal disease, missing teeth, and edentulousness, with either coronary heart disease or a cerebral vascular accident. Six of the studies were longitudinal so that the demonstration of the oral health parameters as significant predictors of the cardiovascular event would elevate the dental parameter to the status of a risk factor. Because dental diseases (especially periodontal disease) are treatable, the dental component is a modifiable risk factor; therefore, maintaining good oral health should receive the highest priority for a healthy life.

Impact of oral diseases on systemic health in the elderly: diabetes mellitus and aspiration pneumonia.

Evidence is increasing that oral health has important impacts on systemic health. This paper presents data from the third National Health and Nutrition Examination Survey (NHANES III) describing the prevalence of dental caries and periodontal diseases in the older adult population. It then evaluates published reports and presents data from clinical and epidemiologic studies on relationships among oral health status, chronic oral infections (of which caries and periodontitis predominate), and certain systemic diseases, specifically focusing on type 2 diabetes and aspiration pneumonia. Both of these diseases increase in occurrence and impact in older age groups. The NHANES III data demonstrate that dental caries and periodontal diseases occur with substantial frequency and represent a burden of unmet treatment need in older adults. Our review found clinical and epidemiologic evidence to support considering periodontal infection a risk factor for poor glycemic control in type 2 diabetes; however, there is limited representation of older adults in reports of this relationship. For aspiration pneumonia, several lines of evidence support oral health status as an important etiologic factor. Additional clinical studies designed specifically to evaluate the effects of treating periodontal infection on glycemic control and improving oral health status in reducing the risk of aspiration pneumonia are warranted. Although further establishing causal relationships among a set of increasingly more frequently demonstrated associations is indicated, there is evidence to support recommending oral care regimens in protocols for managing type 2 diabetes and preventing aspiration pneumonia.

The prevalence of BANA-hydrolyzing periodontopathic bacteria in smokers.

Smoking has been identified as a risk factor for development of periodontal disease and a strong indicator for treatment failure in periodontal patients. This study examined 172 patients categorized as current smokers (n=55), previous smokers (n=38) or individuals that had never smoked (n=79). A total of 670 interproximal plaques collected with a wooden toothpick were analyzed for hydrolysis of the synthetic trypsin substrate benzoyl-DL-arginine naphthylamide (BANA). About 95% of the BANA hydrolysis by plaque is due to the presence of one or more of the periodontopathogens, P. gingivalis, T. denticola or B. forsythus. Gingival health was measured using the papillary bleeding score (PBS). Current smokers had less gingival bleeding than previous smokers or those who had never smoked (20% versus 41% and 25%, respectively). Plaque removed from non-bleeding sites in current smokers were 11x more likely to have a positive BANA reaction when compared to plaque removed from non-bleeding sites in individuals who never smoked. A significant positive relationship exists between smoking and colonization by the BANA periodontopathogens. Smoking may select for these periodontopathic species in the plaque and may be one reason why smoking is a risk factor in periodontal disease development.

Effect of chlorhexidine varnish mouthguards on the levels of selected oral microorganisms in pediatric patients.

PURPOSE: The effect of a chlorhexidine varnish delivery system on the levels of selected oral microorganisms was evaluated in caries active pediatric patients, ages 4 to 12 years old. METHODS: Forty-six patients were enrolled into the study when they had multiple carious surfaces and salivary mutans streptococci (MS) levels higher than 10(4) colony forming units (CFUs) per milliliter. This study incorporated a double-blind design and patients were randomly assigned to either the chlorhexidine treatment group or the placebo group. Complete-arch, vacuum-adapted mouthguards (0.02 in. polypropylene coping material) were custom fabricated and coated internally with either a 3.0% chlorhexidine varnish or a placebo varnish. Two pretreatment paraffin-stimulated saliva samples were obtained for culturing prior to varnish treatment. Saliva samples were also obtained immediately after treatment and once a month for up to three months after wearing the mouthguard appliances. Dental restorations were placed at most of these saliva collection visits. Mouthguards were reportedly worn for an average of 9.7 hours per night for approximately seven nights by 40 subjects (87%). RESULTS: After two months, and after three months, there was a significant reduction in MS levels immediately after the chlorhexidine varnish treatment. Total anaerobic and total facultative bacteria levels were not significantly affected. CONCLUSION: One week of nightly use of the chlorhexidine varnish mouthguard system is effective at reducing the number of MS in caries-active pediatric patients in the mixed and primary dentition for at least three months.

The effects of antimicrobial mouthrinses on oral malodor and their status relative to US Food and Drug Administration regulations.

This study was undertaken to review the rationale behind the usage of antibacterial mouthrinses to control oral malodor and to evaluate the claims made for antibacterial mouthrinses against the statements of US Food and Drug Administration regulations. The literature from 1960 to August 1997, found in a MEDLINE search on oral malodor, halitosis, and tongue microbiology, was examined. Clinical trials that were double blind and had selected subjects who exhibited a detectable level of oral malodor were evaluated. Individuals who experience oral malodor resulting from the overgrowth of proteolytic, anaerobic bacteria on their tongue surfaces can be successfully treated by a regimen that includes tongue brushing and toothbrushing, often in combination with use of a mouthrinse containing an antibacterial agent. Several candidate mouthrinses containing essential oils, zinc chloride, or an oil-water-cetylpyridinium chloride mouthrinse have reduced the organoleptic scores of individuals with moderate levels of oral malodor in the absence of tongue brushing. Very little long-term data beyond 6 weeks of usage are available. These mouthrinses should be marketed as oral deodorants that are analogous in purpose to the usage of deodorant soaps to control and/or eliminate body malodors.

The antimicrobial treatment of periodontal disease: changing the treatment paradigm.

Over the last 100 years, methods of surgical periodontal treatment have enjoyed a history of success in improving oral health. The paradigm of care is based on the "non-specific plaque hypothesis"--that is, the overgrowth of bacterial plaques cause periodontal disease, and the suppression of this overgrowth reduces disease risk. The central feature of this approach to care is the removal of inflamed gingival tissue around the teeth to reduce periodontal pocket depth, thereby facilitating plaque removal by the dentist and by the patient at home. Over the last 30 years, with the recognition that periodontal disease(s) is caused by specific bacteria and that specific antimicrobial agents can reduce or eliminate the infection, a second paradigm has developed. This new paradigm, the "specific plaque hypothesis", focuses on reducing the specific bacteria that cause periodontal attachment loss. The contrast between the two paradigms can be succinctly stated as follows: The antimicrobial therapy reduces the cause, while the surgical therapy reduces the result of the periodontal infection. The specific plaque hypothesis has two important implications. First, with the increasing attention to evidence-based models for prevention, treatment, outcome assessment, and reimbursement of care, increasing attention and financial effort will be channeled into effective preventive and treatment methods. Second, the recent observations that periodontal infections increase the risk of specific systemic health problems, such as cardiovascular disease, argue for the prevention and elimination of these periodontal infections. This review highlights some of the evidence for the specific plaque hypothesis, and the questions that should be addressed if antimicrobial agents are to be used responsively and effectively.

Factors which are associated with dental decay in the older individual.

OBJECTIVES: To improve reliability of salivary bacterial cultures as a surrogate for plaque levels of cariogenic bacterial species by reporting the salivary CFUs of these organisms as a function of the number of teeth. DESIGN: Cross-sectional collection of data in a convenience sample of adults over 60 years of age. SETTING: Hospital Dental clinic, University bacteriology laboratory. SUBJECTS: 523 older dentate subjects, average age 70, including 412 subjects who were in an independent living status and 111 in a dependent-living situation. MAIN OUTCOME MEASURES: Subjects were examined for decay and the presence of salivary factors including the levels of S. mutans, lactobacilli, yeast and other bacteria. The salivary levels of the bacteria were adjusted for the number of teeth in the mouth, and the resultant values were entered into multivariable logistic regression models along with clinical and other salivary parameters. RESULTS: Mutans streptococci levels reported as CFUs/ml saliva per tooth were significantly associated with coronal surface decay, and lactobacilli, reported in a similar way, were significantly associated with root surface decay. Salivary levels of yeasts, which had previously been associated with decay in this population, were no longer significant using this construct. CONCLUSIONS: This construct of reporting salivary bacteriological data as a function of tooth number and per ml saliva could improve the reliability of bacteriological data obtained in epidemiological studies investigating the role of bacteria in dental decay in the elderly.

The relationship between dental disease and cerebral vascular accident in elderly United States veterans.

We report here information obtained from a cross-sectional study of 401 veterans, who were at least 60 years of age, which showed that several dental/oral conditions can be significantly associated with the diagnosis of a cerebral vascular accident (CVA), when included in a multivariate logistic regression model with and without many of the known risk factors for a CVA. The dental findings relative to the prevalence of dental caries and periodontal disease were not distinctly different between the subjects with and without a CVA in the bivariate analysis. A higher stimulated salivary flow was negatively associated with a CVA in the multivariate models. The plaque index and oral hygiene habits relating to brushing, flossing, and frequency of having teeth cleaned by a dentist/hygienist were significantly associated with a CVA in the bivariate analysis. Among these oral hygiene parameters, *needing help in brushing one's teeth" and the reported annual visit to the dentist/hygienist for teeth cleaning remained significant in the multivariate models involving the dependent-living subjects. The need for help in brushing one's teeth could reflect the fact that many subjects had reduced manual dexterity as a result of the CVA and required this extra care. However, the finding that those dependent-living individuals who reported that they did not have their teeth cleaned at least once a year were 4.76 times more likely to have had a CVA, suggests that a pattern of oral neglect might be associated with developing a CVA. The implications of this in terms of an intervention strategy for CVA warrants further consideration. However, caution is recommended because the data were obtained from a convenience sampling of older veterans and may not be generalizable to other populations.

Clinical use of antibiotics in dental practice.

Inappropriate use of antibiotics by clinicians leads to development of antibiotic resistance. For the most part, antibiotics are prescribed in dental practice for prophylactic and therapeutic reasons. Prophylactic antibiotics are prescribed to prevent diseases caused by members of the oral flora introduced to distant sites in a host at risk or introduced to a local compromised site in a host at risk. In most cases, prophylaxis is used for prevention of endocarditis. Therapeutic antibiotics are prescribed, in most cases, to treat diseases of hard and soft tissues in the oral cavity after local debridement has failed. Antibiotics used for prophylaxis must: (1) be active against the major pathogens; and (2) achieve a tissue loading dose before the bacteria are introduced. Antibiotics used for therapy are required in cases where the infection is already present and thus the agent must reach the site of infection at a high enough level for a long enough time to produce the desired effect. For an exogenous agent the goal is to eliminate the agent from the site of infection. In the case of an endogenous agent the antibiotic must suppress the organism at the site of infection. Recent evidence underscores the important role of antibiotics in the treatment and prevention of diseases initiated in the oral cavity that have the potential to spread to distant organs in the body.

Assessing the relationship between dental disease and coronary heart disease in elderly U.S. veterans.

Several recent studies have shown a link between dental disease and coronary heart disease. The authors studied 320 U.S. veterans in a convenience sample to assess the relationship between oral health and systemic diseases among older people. They present cross-sectional data confirming that a statistically significant association exists between a diagnosis of coronary heart disease and certain oral health parameters, such as the number of missing teeth, plaque benzoyl-DL-arginine-naphthylamide test scores, salivary levels of Streptococcus sanguis and complaints of xerostomia. The oral parameters in these subjects were independent of and more strongly associated with coronary heart disease than were recognized risk factors, such as serum cholesterol levels, body mass index, diabetes and smoking status. However, because of the convenience sample studied, these findings cannot be generalized to other populations.