Subgingival microbiota of indigenous Indians of Central America

Periodontal disease prevalence, extent, and risk associations in untreated individuals

Objectives

to examine the prevalence, extent, and risk associations of untreated periodontitis.

Materials and Methods

A purposive sample of subjects who were never treated for periodontal conditions was clinically examined after collecting information about their sociodemographic characteristics, medical conditions, oral health behaviors, perceived stress, and perceived social support.

Results

A total of 431 subjects were recruited (response rate, 97.0%), and their mean age (SD) was 35.4 (13.3) years. Overall, high plaque levels were observed in all untreated individuals. The prevalence of periodontitis and severe (stage III/IV) periodontitis using the American Academy of Periodontology and European Federation of Periodontology (AAP/EFP) classification were 85.4% and 48.5%, respectively. The prevalence of moderate‐severe and severe periodontitis using the definitions of the Centers for Disease Control and Prevention (CDC) and AAP were 78.4% and 31.1%, respectively. The extent of periodontitis expressed as mean% of clinical attachment loss (CAL) ≥ 3 mm and CAL ≥ 5 mm were 34.9% and 14.4%, respectively, while the mean% of a periodontal probing depth (PPD) ≥4 mm and PPD ≥6 mm were 22.0% and 9.2%, respectively. Risk determinants associated with AAP/EFP periodontitis after the adjustment for other variables were age ≥35 years (odds ratio [OR] = 11.5) and lower income (OR = 2.5). Adjusted risk associations with stage II/IV periodontitis included age ≥35 years (OR = 8.2), males (OR = 2.5), lower income (OR = 2.3), and lower perceived stress (OR = 2.0). Adjusted risk associations with CDC/AAP moderate‐severe periodontitis included age ≥35 years (OR = 12.0), lower income (OR = 2.1), and current cigarette smoking (OR = 4.2). Adjusted risk associations with CDC/AAP severe periodontitis included age ≥35 years (OR = 4.5), males (OR = 1.9), lower education (OR = 2.0), lower income (OR = 1.7), uncontrolled diabetes mellitus (OR = 2.0), and current cigarette smoking (OR = 2.3).

Conclusions

The prevalence and extent of periodontitis were high in untreated subjects. Risk associations with untreated periodontitis included age ≥35 years, males, lower income, lower education, current cigarette smoking, uncontrolled diabetes mellitus, and lower perceived stress.

Enhancement of aqueous solubility and antibiofilm activity of 4-allylpyrocatechol by polymeric micelles

4-Allylpyrocatechol (APC), a major active compound of Piper betle, possesses strong antimicrobial activity. However, the water-insoluble property of APC limits its clinical and pharmaceutical use. To solve this problem, APC loaded polymeric micelles (PMAC) was fabricated using the thin-film hydration method. Nanoparticles of PMAC were characterized using a photon correlation spectrophotometer and transmission electron microscope (TEM). Antibiofilm activity of PMAC was investigated using crystal violet assay and confocal laser scanning microscopy (CLSM). Cytotoxic effects of PMAC on normal cells were investigated using MTT assay. The results demonstrate that a ratio of APC to the polymer plays an important role in the physicochemical characteristics of PMAC. The most suitable PMAC formulation having a small particle size (38.8 ± 1.4 nm), narrow size distribution (0.28 ± 0.10), a high negative zeta potential (- 16.43 ± 0.55 mV), and high entrapment efficiency (86.33 ± 14.27%) can be obtained from the ratio 1:4. The water solubility of this PMAC is significantly improved, approximately 1,000-fold higher than the unentrapped APC. TEM images demonstrate that PMAC is spherical in shape. The inhibitory effects of PMAC (1.5 mg APC/mL) against Streptococcus intermedius and Streptococcus mutans biofilms are significantly stronger than chlorhexidine (0.06 mg/mL). Images from CLSM demonstrate the destruction and thickness reduction of the pathogenic biofilms after contacting with PMAC. The MTT assay confirms that PMAC at this concentration is non-toxic to normal cells. These results obviously indicate that PMAC is a promising natural and harmless antimicrobial agent suitable for use in the oral cavity for inhibition of pathogenic bacterial biofilms.

On putative periodontal pathogens: an epidemiological perspective

The current understanding on the role of microbiology on periodontitis causation is reviewed. An appraisal of the literature reveals several issues that have limited the attempts to investigate candidate periodontal pathogens as causes of periodontitis and confirms that only limited epidemiological evidence is available. Several aspects of the contemporary understanding on causal inference are discussed with examples for periodontitis.

Destructive periodontal disease in adult Indians from Northeast Brazil: cross-sectional study of prevalence and risk indicators

AIM

The aim of this cross-sectional study was to evaluate the prevalence of destructive periodontal disease and its risk indicators in adult Kiriri Indians from Northeast Brazil.

MATERIALS AND METHODS

Full-mouth periodontal examinations were performed on a sample of 215 Indians (≥19 years). Bivariate analyses and logistic models were applied to assess associations between periodontitis and its putative risk factors.

RESULTS

Prevalence of clinical attachment loss of ≥3, ≥5 and ≥7 mm was 97.8%, 63.8% and 30.8% respectively. Percentage of teeth per individual showing clinical attachment loss of ≥3, ≥5 and ≥7 mm was 49.8%, 18.4% and 8.0% respectively. After adjustment for covariates, individuals aged ≥35 years (OR = 5.83, 95% CI: 3.09-11.00; p < 0.001), men (OR = 2.18, 95% CI: 1.15-4.11; p = 0.02) and diabetics (OR = 3.92, 95% CI 1.03-14.99; p = 0.05) had a higher risk for destructive periodontitis, classified according to the CDC/AAP case definition.

CONCLUSION

Though periodontitis was highly prevalent in Kiriri Indians, only few teeth showed advanced disease, and periodontitis was associated with higher age, male sex and diabetes. A public health action that includes programs of prevention and treatment targeting high-risk groups is vital to improve the periodontal status of this population.

IL6 -174 genotype associated with Aggregatibacter actinomycetemcomitans in Indians

AIM

Genetic factors have recently been associated with presence of Aggregatibacter actinomycetemcomitans subgingivally in populations living in industrialized countries. The aim of this study was to analyse associations between Interleukin-6 (IL6) single nucleotide polymorphisms and presence and levels of A. actinomycetemcomitans and other subgingival microbes in a rural Indian population.

SUBJECTS AND METHODS

 A total of 251 individuals from a rural village in India with a periodontal phenotype ranging from healthy to severe periodontitis were included. Checkerboard DNA-DNA analysis was performed to detect 40 periodontal taxa in subgingival plaque samples. Genomic DNA was extracted to genotype five polymorphisms in the IL6 promoter region.

RESULTS

The IL6-74 GG genotype was associated with high (above median) counts of A. actinomycetemcomitans (both in all subjects and in periodontally healthy only) and with presence and counts of Capnocytophaga sputigena. Differences in detection of several other bacteria were noted between periodontitis and healthy subjects.

CONCLUSIONS

These findings support the influence of genetic factors on the subgingival microbiota.

Periodontal disease in mothers indicates risk in their children

INTRODUCTION

It is well established that severe periodontitis clusters in families, but there are no data about the relationship between mothers with chronic periodontitis and their children's periodontal status.

OBJECTIVE

To evaluate a risk for periodontal diseases in children of periodontally diseased and healthy mothers.

METHODS

Four study groups were included: (I) 20 female patients with untreated generalized severe chronic periodontitis, (II) their children (34), (III) 13 periodontally healthy mothers and (IV) their children (13). Material was collected from years 2004-2006. The clinical examination included registration of visible plaque index, modified gingival index and, bleeding sites on probing. Periodontal microbiological samples were obtained from all study subjects and the isolates were identified according to morphology and biochemical profiles; similar interfamilial pathogens were compared by PCR-technique.

RESULTS

The children of diseased mothers more frequently had periodontal diseases, especially gingivitis. In addition, clinical parameters of gingival inflammation were more expressed and oral hygiene was worse in this group of children. VPI and VPI% of the diseased and healthy mothers differed significantly. The most common oral pathogens were P. intermedia/nigrescens and A. actinomycetemcomitans. The children of healthy mothers harboured pathogens less frequently than the children of diseased mothers. The sharing of P. intermedia/nigrescens was more frequent (5 families) than A. actinomycetemcomitans (2 families).

CONCLUSION

Maternal indicators, such as periodontitis, hygiene habits, and periodontal microflora are risk factors for childhood periodontal diseases, and might be predictive of future childhood and adolescent periodontitis.

Prevalence and distribution of principal periodontal pathogens worldwide

BACKGROUND

Detailed genetic analysis of bacteria has demonstrated an unanticipated genetic diversity within species, which often reveals evolutionary lineages that are disproportionately associated with infection. There is evidence that some evolutionary lineages of bacteria have adapted to particular ethnic groups.

AIM

This review analyzes to what extent observed differences in periodontal disease prevalence among ethnically or geographically distinct populations may be explained by restricted host adaptation of clones of principal periodontal pathogens.

RESULTS

Carriage rates of several putative periodontal pathogens and particular subsets of these species vary between ethnic groups. Few of these differences can, with the limited information available, be directly related to differences in periodontal disease prevalence. Asian populations are regularly colonized with Actinobacillus actinomycetemcomitans serotype c with questionable pathogenic potential. Conversely, the JP2 clone of A. actinomycetemcomitans has enhanced virulence and causes significantly higher prevalence of aggressive periodontitis in adolescents whose descent can be traced back to the Mediterranean and Western parts of Africa. Some genetically distinct types of Porphyromonas gingivalis are more associated with disease than others, but additional work is required to relate this to clinical differences.

CONCLUSIONS

Studies that take into account differences linked to the genetics of both patients and potential pathogens are likely to give better insight into the aetiology of periodontal diseases.

Periodontitis is associated with a loss of colonization by Streptococcus sanguinis

The aim of this study was to estimate differences in the prevalence of oral streptococcal species in the subgingival biofilm of patients with aggressive periodontitis and of healthy controls. Thirty-three patients with clinical and radiological proof of aggressive periodontitis and 20 healthy subjects were enrolled in this study. Clinical indices were recorded in a six-point measurement per tooth. Samples of the subgingival biofilm were taken with paper points from four teeth of each individual. Alpha- and non-haemolytic, small and catalase-negative colonies were biochemically identified using a rapid ID 32 STREP system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A total of 118 strains of oral streptococci (11 species) were identified and Streptococcus sanguinis was found significantly more often in healthy subjects (P=0.001). Conversely, the absence of S. sanguinis was associated with high values of clinical indices (P=0.001-0.002). Aggressive periodontitis seems to be associated with a loss of colonization of S. sanguinis. Whether or not S. sanguinis offers protection against aggressive periodontitis needs to be determined. Otherwise, there were no significant differences in the distribution of oral streptococcal species in patients and healthy subjects.

Description of the Subgingival Microbiota of Periodontally Untreated Mexican Subjects: Chronic Periodontitis and Periodontal Health

BACKGROUND

Recent studies have suggested that changes in the prevalence and/or proportion of distinct microorganisms characterize the subgingival microbial profiles of populations around the world. At present, no information is available on the subgingival microbiota of Mexican subjects. The purpose of the present study was to determine the microbial composition of subgingival plaque in Mexican subjects with untreated chronic periodontitis.

METHODS

A total of 44 chronic periodontitis and 20 periodontally healthy subjects (who were currently non-smokers) were selected. Clinical measurements including plaque accumulation, gingival erythema, bleeding on probing, suppuration, probing depth, and attachment level were recorded at six sites of every tooth. Up to 28 subgingival plaque samples were obtained from each subject and individually analyzed to determine the levels, proportion, and prevalence of 40 microbial species using the checkerboard DNA-DNA hybridization technique.

RESULTS

Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythensis were the only species that presented higher mean levels in periodontitis subjects. The proportions of P. gingivalis (P<0.001), T. forsythensis (P<0.01), and red complex species (P. gingivalis, T. forsythensis, and T. denticola; P<0.001) as a group were also significantly higher in periodontitis subjects. Periodontally healthy subjects harbored a significantly larger proportion of Actinomyces species (P<0.05). No significant differences were detected in the percentage of carriers of any of the species tested.

CONCLUSIONS

Our results revealed that the subgingival microbiota of untreated chronic periodontitis Mexican subjects was characterized by increases in the level, prevalence, and proportion of classic periodontal pathogens. However, the prevalence and proportion of specific microbial species varied significantly from the results of other reports on subjects from different geographical locations.

Tobacco smoking and periodontal microflora in a Saudi Arabian population

OBJECTIVES

To explore the subgingival periodontal microflora in a Saudi Arabian population with a special focus on its relationship with various smoking habits.

MATERIAL AND METHODS

A total of 198 individuals in the age range 17-60 years were included in the study. 29% were water-pipe smokers, 18% cigarette smokers, 13% smokers of both water pipe and cigarettes (mixed smokers) and 40% non-smokers. For each individual, a subgingival plaque sample from the deepest site in each quadrant was obtained. The checkerboard DNA-DNA hybridization technology was used to determine the presence of Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Tannerella forsythensis, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Treponoma denticola, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Selenomonas noxia and Streptococcus intermedius. Two cut-off levels for detection were used, score 1(10(5) bacteria) and score 3 (10(6) bacteria).

RESULTS

The prevalence of individuals positive for the different microorganisms at score 1 cut-off varied from 7% to 95%. At score 3 cut-off the prevalence varied from 0% to 30%. The depth of sample site was a key factor for detection. When the depth of sample site was taken into account, no statistically significant differences were observed between cigarette smokers, water-pipe smokers, and non-smokers with regard to occurrence of the microorganisms studied.

CONCLUSIONS

No major differences were observed between cigarette smokers, water-pipe smokers, and non-smokers regarding the occurrence of the periodontal microorganisms studied suggesting that this portion of the subgingival periodontal microflora is independent of tobacco smoking.

Subgingival microbiota of chronic periodontitis subjects from different geographic locations

BACKGROUND

Most clinical studies assume that the subgingival microbiota is similar from one geographic location to another. The purpose of the present investigation was to examine the composition of the subgingival microbiota in chronic periodontitis subjects from four countries.

METHOD

Subjects with chronic periodontitis (N, Sweden=101; USA=115; Brazil=58; Chile=26) were recruited. Subjects were measured at baseline for plaque, gingivitis, bleeding on probing (BOP), suppuration, pocket depth (PD) and attachment level (AL) at six sites per tooth. Subgingival plaque samples taken from the mesial aspect of each tooth at baseline were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization (total samples=6036). % DNA probe counts comprised by each species was determined for each site and averaged across sites in each subject. Significance of differences in proportions of each species among countries was determined using ancova adjusting for age, mean pocket depth, gender and smoking status. p-Values were adjusted for multiple comparisons.

RESULTS

On average, all species were detected in samples from subjects in the four countries. Thirteen species differed significantly in adjusted mean proportions among countries even after adjusting for multiple comparisons. Porphyromonas gingivalis, one species that differed in proportions among countries, comprised adjusted means of 7.5, 11.9, 1.6 and 6.6% of the microbiota in subjects from Brazil, Chile, Sweden and USA (p<0.001), while mean proportions of Treponema denticola were 6.7, 4.2, 0.8 and 2.3, respectively (p<0.001). In contrast, a key periodontal pathogen, Tannerella forsythensis, exhibited mean proportions ranging from 6.2-8.5% and did not differ significantly among countries. Besides these species, prominent species in Brazil were Actinomyces naeslundii genospecies 1 and 2 (8.4%, 7.2%) and Prevotella intermedia (6.5%); in Chile, Prevotella melaninogenica (6.4%) and Neisseria mucosa (5.3%); in Sweden A. naeslundii genospecies 2 (8.4%), Capnocytophaga gingivalis (7.1%) and Peptostreptococcus micros (5.0%); in USA A. naeslundii genospecies 2 (7.5%), P. intermedia (6.8%) and C. gingivalis (6.1%).

CONCLUSIONS

The microbial profiles of subgingival plaque samples from chronic periodontitis subjects in four countries showed surprisingly marked differences. These differences persisted after adjusting for age, mean pocket depth, gender and smoking status.

The effect of shared genetic and environmental factors on periodontal disease parameters in untreated adult siblings in Guatemala

BACKGROUND

Increasing evidence supports the role of genetic factors in susceptibility to infectious diseases, including chronic periodontitis. The role of genetic factors in phenotypic expression can be estimated from the degree of resemblance between relatives, as compared with that of unrelated members of a population. Heritability is an estimate of the proportion of total phenotypic variation of a quantitative trait, which is attributable to genetic factors, and is based on the variance within versus between family members. The aim of this study was to determine whether there is a familial basis for periodontal disease status in an untreated population in Guatemala using heritability estimates as a measure of familial clustering of disease.

METHODS

One-hundred and thirteen adult subjects (including both siblings and spouse pairs), age range 35 to 60 years, participated in this study. Full-mouth periodontal examinations were performed and heritability estimates were calculated for mean plaque score, mean gingival index (GI), probing depth (PD), and clinical attachment level (CAL). Intraclass correlation coefficients (ICCs) were calculated using the same parameters for spouses to determine whether a common family environment in adulthood plays a role in disease expression.

RESULTS

Only in the case of mean plaque score and mean recession score were heritability estimates significantly above zero at alpha = 0.05. For spouse pairs, mean GI score, mean PD, and percentage of sites of PD > or = 5 mm showed a statistically significant ICC.

CONCLUSIONS

These results lead us to reject the hypothesis that there is substantial heritability for periodontal disease expression in this population. This may be due to an underlying lack of genetic variation within this sample or may indicate that, compared with the role of environmental factors, the genetic contribution to periodontal disease phenotypes is relatively minor.

Extending scientific horizons in the developing world - the Central American experience

The juxtaposition of 'oral disease' and 'developing countries' invariably evokes thoughts of how one might assist these nations in attaining 'a healthy mouth for all' according to Western standards. In this discussion, the emphasis is shifted to consider collaborations between the industrial nations and those less developed countries, in the conduct and development of research. This potentially fruitful partnership can produce scientific, educational and cultural rewards for mutual benefit.

The Applicability of Half-Mouth Examination to Periodontal Disease Assessment in Untreated Adult Populations

BACKGROUND

Data from whole-mouth examinations are the gold standard for accurate assessment of periodontal disease. Since periodontal destruction exhibits left-right symmetry, however, it is hypothesized that a half-mouth exam provides an appropriate alternative to whole-mouth assessment, with considerable advantage over a more limited partial-mouth assessment of index teeth.

METHODS

Data from 2 untreated populations were utilized in the analyses. Half-mouth (random diagonal quadrants) and Ramfjord teeth assessment was compared with whole-mouth assessment as follows. Intraclass correlation coefficients (ICCs) were calculated for mean plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) and for percentage of sites with PD > or = 4, 5, or 6 mm; CAL > or = 3, 4, 5, or 6 mm; and recession > or = 3 mm to determine the agreement between the whole- and partial-mouth assessment. Disease prevalence was also determined for both whole- and partial-mouth assessments.

RESULTS

For mean PI, GI, PD, and CAL, both half-mouth and Ramfjord teeth assessment provided an acceptable alternative to whole-mouth assessment (ICCs > 0.92). For percentage of sites above a specified threshold, ICCs were generally greater than 0.90 in all age cohorts for half-mouth assessment, but consistently lower for Ramfjord teeth assessment. Ramfjord teeth assessment also considerably underestimated disease prevalence compared with half-mouth assessment.

CONCLUSIONS

These results support the use of a half-mouth examination procedure, to conserve time, limit cost, and reduce patient and examiner fatigue while providing maximal clinical information. Ramfjord teeth assessment was not as suitable for evaluation of either disease extent or prevalence.