The use of a rapid enzymatic assay in the field for the detection of infections associated with adult periodontitis

Targeted Proteomics Guided by Label-free Quantitative Proteome Analysis in Saliva Reveal Transition Signatures from Health to Periodontal Disease

Periodontal diseases are among the most prevalent worldwide, but largely silent, chronic diseases. They affect the tooth-supporting tissues with multiple ramifications on life quality. Their early diagnosis is still challenging, due to lack of appropriate molecular diagnostic methods. Saliva offers a non-invasively collectable reservoir of clinically relevant biomarkers, which, if utilized efficiently, could facilitate early diagnosis and monitoring of ongoing disease. Despite several novel protein markers being recently enlisted by discovery proteomics, their routine diagnostic application is hampered by the lack of validation platforms that allow for rapid, accurate and simultaneous quantification of multiple proteins in large cohorts. Here we carried out a pipeline of two proteomic platforms; firstly, we applied open ended label-free quantitative (LFQ) proteomics for discovery in saliva (n = 67, including individuals with health, gingivitis, and periodontitis), followed by selected-reaction monitoring (SRM)-targeted proteomics for validation in an independent cohort (n = 82). The LFQ platform led to the discovery of 119 proteins with at least 2-fold significant difference between health and disease. The 65 proteins chosen for the subsequent SRM platform included 50 functionally related proteins derived from the significantly enriched processes of the LFQ data, 11 from literature-mining, and four house-keeping ones. Among those, 60 were reproducibly quantifiable proteins (92% success rate), represented by a total of 143 peptides. Machine-learning modeling led to a narrowed-down panel of five proteins of high predictive value for periodontal diseases with maximum area under the receiver operating curve >0.97 (higher in disease: Matrix metalloproteinase-9, Ras-related protein-1, Actin-related protein 2/3 complex subunit 5; lower in disease: Clusterin, Deleted in Malignant Brain Tumors 1). This panel enriches the pool of credible clinical biomarker candidates for diagnostic assay development. Yet, the quantum leap brought into the field of periodontal diagnostics by this study is the application of the biomarker discovery-through-verification pipeline, which can be used for validation in further cohorts.

A simple point of care test can indicate the need for periodontal therapy to reduce the risk for adverse pregnancy outcomes in mothers attending antenatal clinics

INTRODUCTION

Although the association between periodontal disease (PD) and adverse pregnancy outcomes has gained recognition amongst antenatal healthcare workers, not much has changed in practice to address it. This prospective study tested the hypothesis that BANA (N-benzoyl-DL-arginine-2-naphthylamide), a diagnostic test for PD, may inform obstetricians and other antenatal healthcare practitioners, of the risk of adverse pregnancy outcomes in mothers attending antenatal clinics.

METHODS

At first visit, the presence of suspected periodontopathogens was assessed by BANA testing of dental plaque from 443 mothers attending antenatal clinics in KwaZulu-Natal, South Africa and an association later sought with pregnancy outcomes. The accuracy of BANA to predict adverse pregnancy outcomes was evaluated by the calculation of likelihood ratios. The study complied with the Declaration of Helsinki.

RESULTS

Significant differences were found between pregnancy outcomes of BANA-negative and BANA-positive mothers (p < 0.0001). BANA showed sensitivity and negative predictive values of 87% and 91%; 75% and 78%; 87% and 94% in detecting low birth weight, preterm delivery, and preterm low birth weight delivery respectively.

CONCLUSION

This study confirms that BANA may indicate the need for periodontal therapy to reduce the risk of adverse pregnancy outcomes and could form part of the routine antenatal examination.

Recording and surveillance systems for periodontal diseases

This paper describes tools used to measure periodontal diseases and the integration of these tools into surveillance systems. Tools to measure periodontal diseases at the surveillance level have focussed on current manifestations of disease (e.g. gingival inflammation) or disease sequelae (e.g. periodontal pocket depth or loss of attachment). All tools reviewed in this paper were developed based on the state of the science of the pathophysiology of periodontal disease at the time of their design and the need to provide valid and reliable measurements of the presence and severity of periodontal diseases. Therefore, some of these tools are no longer valid. Others, such as loss of periodontal attachment, are the current de-facto tools but demand many resources to undertake periodical assessment of the periodontal health of populations. Less complex tools such as the Community Periodontal Index, have been used extensively to report periodontal status. Laboratory tests for detecting putative microorganisms or inflammatory agents present in periodontal diseases have been used at the clinical level, and at least one has been tested at the population level. Other approaches, such as self-report measures, are currently under validation. In this paper, we do not review indices designed to measure plaque or residual accumulation around the tooth, indices focussed only on gingival inflammation or radiographic approaches with limited applicability in surveillance systems. Finally, we review current case-definitions proposed for surveillance of periodontal disease severity.

The transmission of BANA-positive periodontal bacterial species from caregivers to children

BACKGROUND

The purpose of the authors' study was to use the N-benzoyl-DL-arginine-2-naphthy-lamide (BANA) test (BANAMet LLC, Ann Arbor, Mich.) to obtain information regarding the prevalence of an enzyme unique to certain periodontal pathogens in plaque samples of children, as well as the potential transmission of these pathogens from caregivers to children.

METHODS

The authors tested 218 subjects (3 to 10 years old) and 195 care-givers at four pediatric dentistry clinics in Taipei, Taiwan.

RESULTS

Forty-four percent of the children had at least one plaque sample that tested positive and/or weakly positive. Positive results were more frequent in the mixed dentition, as well as in children with gingivitis (P < .001). A logistic regression model showed that if the BANA test results for the care-giver were positive, the odds of the child's also having positive test results were 55 times greater (P < .001; confidence interval [CI] = 14 to 224) than those for a child whose caregiver had negative BANA test results. Other predictors were the presence of a mixed dentition (P < .001; odds ratio [OR] = 11; CI = 3.5 to 33.5) and the children's papillary bleeding scores (P < .001, OR = 3.1, CI = 2.0 to 4.7).

CONCLUSION

The BANA test results were positive for almost one-half of the children. A positive reaction was associated with gingivitis, a mixed dentition, a BANA-positive caregiver or a caregiver with a history of periodontal disease in the family.

CLINICAL IMPLICATIONS

The authors propose an anaerobic periodontal infection risk model in which children with a mixed dentition who have gingivitis and a caregiver with a history of periodontal disease would undergo the BANA test.

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.

A Comparison of the Gingival Health of Children with Down Syndrome to Healthy Children Residing in an Institution

The purpose of this study was to compare the onset and severity of gingivitis in children with Down syndrome, when compared to a healthy control group of children. The subjects included 41 children with Down syndrome ages two to 14 years (mean age: 7.6 years) and 112 age-matched healthy controls. We assessed the gingival health of all subjects using the gingival inflammation (M-PMA) index and periodontal probing depth (PD). Children were divided into three age categories: <5 years (AI), 5 to <10 years (AII), and 10 to <17 years (AIII). Supragingival plaque was measured using the Oral Hygiene Index (OHI) and the subjects were screened with the BANA test (Perioscan-Oral-B). Measurement of the M-PMA index in the healthy children showed an age-related increase (F = 10.369, p < 0.001), and the M-PMA index at the younger age group <5 year (AI) was significantly lower than that for the other two age groups All or AIII (p < 0.005, p < 0.001). In contrast, the M-PMA index values at AI and AIII in the subjects with Down syndrome were significantly higher than those for healthy children (p < 0.001, p < 0.001). Both groups had an age-related increase in PD (F = 3.388, p < 0.05 & F = 10.806, p < 0.001), and PD at AIII was significantly higher than that at AI in both groups (p < 0.01, p < 0.001). The children with Down syndrome showed an age-related increase in the BANA test score (F = 3.452, p < 0.05), and the BANA test score at AIII was significantly higher than that at AI (p < 0.02). The BANA test score in the healthy children was not age-related but was significantly higher than that in the children with Down syndrome (p < 0.02, p < 0.05).

Position Paper: Diagnosis of Periodontal Diseases

At the present time, the diagnosis and classification of periodontal diseases are almost entirely based on traditional clinical assessments. Supplemental quantitative and qualitative assessments of the gingival crevicular fluid and subgingival microflora can potentially provide useful information about the patient's periodontal disease. In certain situations, these supplemental risk-assessment tests may be particularly valuable in establishing the endpoint of therapy prior to placing patients on a periodontal maintenance program. Although the clinical utility of none of these tests has been validated, their further development is warranted. A genetic test for susceptibility to periodontitis has become commercially available. How best to use this and future host-based tests in clinical practice remains to be determined. Probing depth and clinical attachment loss measurements obtained with periodontal probes are practical and valid methods for assessing periodontal status. Computer-linked, controlled-force electronic periodontal probes are commercially available and are currently in use by some practitioners. Many of the logistical problems associated with subtraction radiography are being overcome and this powerful diagnostic tool may soon come into widespread use. Future developments in this and other imaging techniques are likely to have a profound effect on our approach to the diagnosis of periodontal diseases.

Validity of two methods for assessing oral health status of populations

OBJECTIVE

This investigation assessed two methods for estimating epidemiologic indicators of oral health status among children: (1) a visual-only screening, performed independently by a dental hygienist and a registered nurse; and (2) a parent- or guardian-completed questionnaire. The indicators included dichotomous variables measuring dental caries and treatment needs, presence of sealants, injuries to the anterior teeth, and dental fluorosis.

METHODS

Following training and calibration, data were collected over an eight-day period in April 1994 among 632 elementary schoolchildren (aged 5 to 12 years) in Monticello, Georgia. Both screening and questionnaire findings were compared pairwise with results from visual-tactile examinations done by a dentist. Validity, represented by sensitivity, specificity, and predictive values, was assessed for screening results from the dental hygienist, the nurse, and the parent-completed questionnaire.

RESULTS

Validity was high for screening for caries and treatment needs (> 90% for sensitivity, specificity, and predictive values in a sample having 30% to 40% prevalence). Less valid data--mainly an effect of false negatives--were obtained for fluorosis, injuries, and presence of sealants. No significant difference in validity was observed between the nurse and the dental hygienist. One-third of respondents to the questionnaire did not know if their children needed fillings (a proxy for untreated decay) or had received sealants; only knowledge of restorations was comparable to results from screening. Intraexaminer reliability for the two screeners ranged from 85 to 100 for percent agreement and 0.70 to 0.93 for kappa scores.

CONCLUSIONS

Screening by dental hygienists or nurses can provide valid data for surveillance of dental caries and treatment needs. Training for visual assessment of fluorosis and injuries must be improved to diminish the proportion of false negatives. A parent-completed questionnaire is less effective than visual screening for evaluating oral health status in children.

The optimization of the BANA test as a screening instrument for gingivitis among subjects seeking dental treatment

Porphyromonas gingivalis, Treponema denticola and Bacteroides forsythus have been implicated in periodontal disease and each possesses an enzyme capable of hydrolyzing the synthetic trypsin substrate, BANA. We have used a chairside test for BANA hydrolysis to diagnose an anaerobic periodontal infection in patients with advanced forms of clinical disease using a 15-min/55 degrees C incubation protocol. However, the BANA test performance is dependent upon the length and temperature of incubation. In the present study, we have evaluated a 5-min/35 degrees C, a 5-min/55 degrees C and a 15-min/55 degrees C incubation protocol to determine whether the performance of the BANA test could be optimized using plaque samples obtained from subjects seeking dental treatment. Logistic regression models were tested with age, smoking status, and gingivitis scores as covariates. The best fitting model obtained with the 5-min/35 degrees C protocol had a sensitivity of 71%, a specificity of 68%, a false-positive proportion of 9%, a false-negative proportion of 65%, and an overall accuracy of 80%. When maximum likelihood estimates were obtained in this model, plaques from individuals who reported that they currently smoked were 9.57x, and those who quit smoking were 4.73x more likely to have a positive BANA score than someone who never smoked. Plaques were 4.55x more likely to be BANA-positive if they were removed from sites with gingivitis. These findings indicate that the performance of the BANA test is best using the 5-min/35 degrees C incubation protocol.

Assessment of pretreatment orthodontic patients using the BANA test. N-benzoyl-DL-arginine-naphthylamide

Ninety-two subjects were tested before orthodontic mechanotherapy for the presence of three putative periodontopathogens-Porphyromonas gingivalis, Treponema denticola, and Bacteroides forsythus-with the BANA test (PerioScan Oral-B). The sample ranged from 9 to 16 years, with a mean age of 13.1 years, and consisted of 51% girls and 49% boys; 48% African American, 46% white, 4% Asian, and 2% Hispanic. Unlike other BANA studies that examined children and adolescents with a 15-minute incubation time, this research used a 5-minute incubation time to increase the specificity and to reduce the false positives obtained from the PerioScan cards. No statistically significant difference was found between the age, gender, or race of the patients and the levels of the three putative periodontopathogens. A Friedman two-way analysis of variance assessed the BANA levels for three groups of teeth: molars, incisors, and premolars. The central incisors and first molars had a significantly higher percentage of positive BANA readings than the first premolars at p < or = 0.05. The clinical importance of this finding has yet to be determined, however, because the central incisor and first molar are the first permanent teeth to erupt, a possible association between dental emergence time and the rate of infection with various organisms may be postulated. In a pilot study, 10 patients from a statistically comparable pretreatment group were assessed longitudinally at two separate collection times separated by 4 months. The Wilcoxon signed rank test indicated no significant changes in these patients over the 4-month period.