Prevalence of periodontitis and suspected periodontal pathogens in families of adult periodontitis patients

Insights into the variations in microbial community structure during the development of periodontitis and its pathogenesis

OBJECTIVE

To characterize the subgingival microbiota in subjects with stage I/II periodontitis (moderate periodontitis, MP), stage III/IV periodontitis (severe periodontitis, SP), and periodontal health (PH) at the same probing depth (PD) (shallow ≤ 3 mm, moderate 4-6 mm, or deep ≥ 7 mm), and to investigate the changes associated with probing depth progression.

MATERIALS AND METHODS

100 subgingival plaque samples were collected from 50 subjects (16 MP, 17 SP and 17 PH), forming six groups: PHS (PH, shallow), MPS (MP, shallow), MPM (MP, moderate), SPS (SP, shallow), SPM (SP, moderate), and SPD (SP, deep). Samples were analyzed using high-throughput sequencing.

RESULT

The subgingival microbiome showed significant differences associated with both PD and periodontitis stage (p < 0.05). With increasing PD, alpha diversity initially increased and then decreased. Pathogenic genera like Fusobacterium, Filifactor, and Porphyromonas increased, while health-associated genera like Streptococcus and Haemophilus decreased. At shallow sites, the PHS, MPS, and SPS groups showed similar community structure. At moderate and deep sites, the SPM and SPD groups exhibited significant differences in community structure compared to the MPM group, with the SPM and SPD groups showing decreased abundances of Actinomyces and increased abundances of Treponema. The microbial co-networks in the SPD and SPM groups exhibited greater complexity and connectivity and were more resilient to random microbial or node removal.

CONCLUSIONS

The subgingival microbiome shows strong associations with PD and periodontitis stage.

CLINICAL RELEVANCE

Once periodontitis progresses to stage III/IV, reconstructing a healthy subgingival microbiome may be challenging, emphasizing the importance of early prevention.

The promise and challenges of genomics-informed periodontal disease diagnoses

Recent advances in human genomics and the advent of molecular medicine have catapulted our ability to characterize human and health and disease. Scientists and healthcare practitioners can now leverage information on genetic variation and gene expression at the tissue or even individual cell level, and an enormous potential exists to refine diagnostic categories, assess risk in unaffected individuals, and optimize disease management among those affected. This review investigates the progress made in the domains of molecular medicine and genomics as they relate to periodontology. The review summarizes the current evidence of association between genomics and periodontal diseases, including the current state of knowledge that approximately a third of the population variance of periodontitis may be attributable to genetic variation and the management of several monogenic forms of the disease can be augmented by knowledge of the underlying genetic cause. Finally, the paper discusses the potential utility of polygenic risk scores and genetic testing for periodontitis diagnosis now and in the future, in light of applications that currently exist in other areas of medicine and healthcare.

Evaluation of the Genetic Association and Methylation of Immune Response Pathway Genes with the Risk of Chronic Periodontitis in the Uighur Population

Aim: The aim of this study was to explore the possible associations between single nucleotide polymorphisms (SNPs) and DNA methylation levels of seven genes in the inflammatory response pathway with susceptibility to chronic periodontitis (CP) among the Uighur population of the Xinjiang Autonomous Region of China. Methods: A total of 444 eligible subjects (279 CP patients and 165 healthy controls) were enrolled in the study. Genomic DNA was obtained from gingival tissue for genotyping eight SNPs and performing methylation measurements of seven genes. Results: SNP rs2070745 in the formyl peptide receptor 1 (FPR1) gene achieved statistical significance in a standard allelic association analysis for CP (p = 0.02). The frequency of the rs2070745 minor allele G was higher in the cases than in controls (0.367 vs. 0.291). Additionally, rs2070745 was significantly associated with CP under the dominant genetic model (p = 0.03). Using logistic regression analysis, rs2070745 was found to be consistently associated with CP under the additive dominant model, and this association remained significant after covariates were taken into account [odds ratio (OR) = 1.49 (1.09-2.05), p = 0.014; OR = 1.58 (1.04-2.40), p = 0.031, respectively]. No significant gene-gene interactions were identified. Although we did not find a polymorphism in interleukin 6 (IL6) associated with CP in our study, the methylation level of a CpG island region located within the promoter region of IL6 was significantly less in CP patients compared with controls (p < 0.05). Conclusions: The genetic polymorphism rs2070745 in FPR1 and the methylation level of the promoter region of IL6 might be associated with CP in the Uighur population of China.

Familial tendency as a determinant of tooth loss during long-term periodontal therapy

AIM

Little evidence exists on how familial tendencies affect the long-term success of periodontal therapy. The aim of this study was to compare outcomes for two generations and their control patients treated in the same private practice.

MATERIALS/METHODS

Parents and their children were observed for tooth loss between 1986 and 2017. Matching control groups were identified from the same practice, one for the parent and one for the children group. The control patients had no close family members with a history of periodontal diseases. Both the generations and control groups completed a similar course of periodontal therapy. The matching strategy aimed at making the groups as similar as possible with respect to well-known risk and prognostic factors. The data were analysed by multiple regression where the outcome was the number of teeth lost due to periodontal disease.

RESULTS

A total of 435 patients were identified (148 parents, 154 children and 133 controls). 72 parents and 61 children (133) had more than 5 years follow-up (average 15.5 and 12.9 years, respectively). Balancing tests showed that the matching was successful. 65% of tooth loss was attributable to close family history. The regression showed that the parent generation lost 1.02 more teeth than the controls, while the children lost 0.61 more teeth.

CONCLUSION

Having close family members with a history of periodontal diseases is a strong prognostic factor affecting the long-term outcome of periodontal therapy.

Shared detection of Porphyromonas gingivalis in cohabiting family members: a systematic review and meta-analysis

Introduction: Periodontitis is an inflammatory dysbiotic disease. Among putative dysbiosis causes, transmission of Porphyromonas gingivalis between individuals of the same family remains unclear. The aim of this systematic review and meta-analysis is to assess the likelihood of shared detection of Porphyromonas gingivalis among cohabiting family members.

Methods: A literature search was conducted on different databases up to September 2018. Articles assessing the presence of P.gingivalis between members of the same family were screened. Only English literature was retrieved, whereas no limits were applied for bacterial sampling and detection methods.

Results: Overall, 26 articles published between 1993 and 2017 met the inclusion criteria. Of these, 18 articles were used for meta-analyses. Based on bacterial culture, the likelihood of an intra-familial transmission of P.gingivalis once a member of the family harbors the bacterium is estimated at 63.5% (n = 132 pairs of family members); this drops to 45% when pooling together culture and Polymerase-Chain-Reaction (n = 481 pairs), whereas it is estimated at 35.7% when genotyping is applied (n = 137 pairs).

Conclusion: Pooled results suggest that the likelihood of detecting P.gingivalis within within family members is moderately frequent. Personalized periodontal screening and prevention may consider intra-familial co-occurrence of P.gingivalis as feasible.

Prevalence of Periodontal Destruction and Putative Periodontal Pathogens in the Same Lebanese Family

AIM

Periodontal diseases are associated with microorganisms rich in Gram-negative species. Several studies have indicated the presence of few a periodontopathic microorganisms in the same family. A parent with severe adult periodontitis, who is infected with bacteria associated with periodontal disease, may function as a source of infection. Their children may be at a greater risk to become colonized with bacteria. The purpose of this investigation was (1) to explore the presence of three bacteria, such as Porphyromonas gingivalis (PG), Prevotella intermedia (PI), and Aggregatibacter actinomycetemcomitans (AA) in the same Lebanese family and (2) to study the clinical destruction in the same family and their relations as members of this family due to the presence of PG.

MATERIALS AND METHODS

A total of 10 families were screened; only 5 (13 females and 5 males) were selected for this study, and at least one member of the family had untreated periodontal disease, chronic or aggressive. Every participant signed an informed consent form. A total of 18 available deoxyribonucleic acid (DNA) samples were taken to analyze the presence of three periodontal bacteria.

STATISTICS

Multiple logistic regression was used for the exact methods.

RESULTS

All 18 patients showed a positive result for PI. Also, PG. was recognized in 15 patients while AA was not detected in any of the subjects. All couples suffered from periodontitis, chronic or aggressive forms, five children suffered from gingivitis, three children had no clinical manifestation, and only one suffered from localized aggressive periodontitis. The statistical analysis showed with each 1 year of increase in age, the odds of having periodontal disease multiply by 1.39, i.e., age as a risk factor for periodontal disease due to the presence of PG and sharing the same plate.

CONCLUSION

This investigation demonstrates a high prevalence of periodontal microorganisms in children and young adults of Lebanese periodontitis parents and a microbiological similarity between the children and their mothers. All these factors could be a high risk of developing periodontal disease in the future.

CLINICAL SIGNIFICANCE

This article shows that vertical transmission of microorganisms is a possible risk factor for developing periodontal disease in the offspring.

In Vitro Effects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm

Polyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells of Prevotella intermedia, a major oral pathogen. The MIC of polyP3 against P. intermedia ATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal against P. intermedia in time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers of P. intermedia cells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced by P. intermedia were decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent against P. intermedia in biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium.

The Oral Microbiota

The oral microbiota represents an important part of the human microbiota, and includes several hundred to several thousand diverse species. It is a normal part of the oral cavity and has an important function to protect against colonization of extrinsic bacteria which could affect systemic health. On the other hand, the most common oral diseases caries, gingivitis and periodontitis are based on microorganisms. While (medical) research focused on the planktonic phase of bacteria over the last 100 years, it is nowadays generally known, that oral microorganisms are organised as biofilms. On any non-shedding surfaces of the oral cavity dental plaque starts to form, which meets all criteria for a microbial biofilm and is subject to the so-called succession. When the sensitive ecosystem turns out of balance - either by overload or weak immune system - it becomes a challenge for local or systemic health. Therefore, the most common strategy and the golden standard for the prevention of caries, gingivitis and periodontitis is the mechanical removal of this biofilms from teeth, restorations or dental prosthesis by regular toothbrushing.

The presence of cariogenic and periodontal pathogens in the oral cavity of one-year-old infants delivered pre-term with very low birthweights: a case control study

Background

Recently, the dental literature has focused mainly on the microbial colonization of healthy full-term infants and their mothers or caretakers. However, oral microbial acquisition by premature infants has not been adequately investigated, and the correlation between pre-term birth and the presence of cariogenic and periodontal pathogens has not been determined. The aim of this study was to identify the presence and quantities of representative cariogenic and periodontal pathogens in the oral cavities of 12-month-old infants and compare the occurrence of these microbes between a cohort of pre-term infants with very low birthweights and a control cohort comprising full-term infants.

Methods

The research cohort was composed of 69 one-year-old infants, of whom 24 were born prematurely with very low birthweights and 45 of whom were carried to full term. Information regarding the infants’ gestational age, mode of delivery, general health status, birthweight and antibiotic use were obtained from hospital records and through oral interviews. At 12 months of age, both groups of infants were examined, and unstimulated saliva samples from the dorsum of the tongue and dental plaque samples were collected. The microorganisms (Streptococcus mutans, Lactobacillus spp., Actinomyces spp., Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Peptostreptococcus micros, Prevotella intermedia, Fusobacterium nucleatum) were identified and their quantities were evaluated using a PCR-based method. The chi-squared and Fisher’s factorial tests were used for the statistical evaluations.

Results

The infants had a high prevalence of cariogenic microbes and of Fusosbacterium nucleatum and Aggregatibacter actinomycetemcomitans. Cariogenic microbes were detected in 91.7% of the very low birthweight infants and in all full-term infants. Periodontal pathogens were present in 83% of the pre-term infants and in 96% of the full-term infants. A significant difference was found between the cohorts in terms of the presence of S. mutans. Most of the very low birthweight infants had negative values of this microbe, while the full-term infants had positive values.

Conclusions

This study confirms the early transmission of representative cariogenic and periodontal pathogens to the oral cavity of one-year-old infants and a higher prevalence of S. mutans in full-term infants than in premature infants.

Risk factors for periodontal disease

Risk factors play an important role in an individual's response to periodontal infection. Identification of these risk factors helps to target patients for prevention and treatment, with modification of risk factors critical to the control of periodontal disease. Shifts in our understanding of periodontal disease prevalence, and advances in scientific methodology and statistical analysis in the last few decades, have allowed identification of several major systemic risk factors for periodontal disease. The first change in our thinking was the understanding that periodontal disease is not universal, but that severe forms are found only in a portion of the adult population who show abnormal susceptibility. Analysis of risk factors and the ability to statistically adjust and stratify populations to eliminate the effects of confounding factors have allowed identification of independent risk factors. These independent but modifiable, risk factors for periodontal disease include lifestyle factors, such as smoking and alcohol consumption. They also include diseases and unhealthy conditions such as diabetes mellitus, obesity, metabolic syndrome, osteoporosis, and low dietary calcium and vitamin D. These risk factors are modifiable and their management is a major component of the contemporary care of many periodontal patients. Genetic factors also play a role in periodontal disease and allow one to target individuals for prevention and early detection. The role of genetic factors in aggressive periodontitis is clear. However, although genetic factors (i.e., specific genes) are strongly suspected to have an association with chronic adult periodontitis, there is as yet no clear evidence for this in the general population. It is important to pursue efforts to identify genetic factors associated with chronic periodontitis because such factors have potential in identifying patients who have a high susceptibility for development of this disease. Many of the systemic risk factors for periodontal disease, such as smoking, diabetes and obesity, and osteoporosis in postmenopausal women, are relatively common and can be expected to affect most patients with periodontal disease seen in clinics and dental practices. Hence, risk factor identification and management has become a key component of care for periodontal patients.

Role of familiarity versus interleukin-1 genes cluster polymorphisms in chronic periodontitis

Periodontitis (PO) is a multifactorial disease affecting about 10% to 20% of the general population. Several studies have suggested that part of the clinical variability in PO might be explained by genetic factors. Among the candidate genes for PO, IL1 gene polymorphisms have been broadly investigated, with variable results, for their relationship with the disease. We studied three IL1 polymorphisms, IL1A C[-889]T (rs1800587), IL1B C[3953/4]T (rs1143634), and IL1RN VNTR [+2018] (rs419598) in relation to different life styles and familiarities. We did not find correlation between these IL1 polymorphisms and chronic PO, as well as between chronic PO and life styles (smoking, alcohol, coffee, fizzy drink and fish). We found a strong correlation, also after adjustment for age, between familiarity and PO onset (P=0.0062; OR 5.754, 95% CI 1.644-20.145). In conclusion, we did confirm the previously suggested association between PO and IL1 gene cluster polymorphisms, and between PO and four common risk factors (coffee, smoking, alcohol and fizzy drinks) and one common protective factor (fish). On the contrary, we found a strong role of familiarity.

Antibacterial and antibiofilm effects of iron chelators against Prevotella intermedia

Prevotella intermedia, a major periodontopathogen, has been shown to be resistant to many antibiotics. In the present study, we examined the effect of the FDA-approved iron chelators deferoxamine (DFO) and deferasirox (DFRA) against planktonic and biofilm cells of P. intermedia in order to evaluate the possibility of using these iron chelators as alternative control agents against P. intermedia. DFRA showed strong antimicrobial activity (MIC and MBC values of 0.16 mg ml−1) against planktonic P. intermedia. At subMICs, DFRA partially inhibited the bacterial growth and considerably prolonged the bacterial doubling time. DFO was unable to completely inhibit the bacterial growth in the concentration range tested and was not bactericidal. Crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that DFRA significantly decreased the biofilm-forming activity as well as the biofilm formation, while DFO was less effective. DFRA was chosen for further study. In the ATP-bioluminescent assay, which reflects viable cell counts, subMICs of DFRA significantly decreased the bioactivity of biofilms in a concentration-dependent manner. Under the scanning electron microscope, P. intermedia cells in DFRA-treated biofilm were significantly elongated compared to those in untreated biofilm. Further experiments are necessary to show that iron chelators may be used as a therapeutic agent for periodontal disease.

Bradykinin promotes Toll like receptor-4 expression in human gingival fibroblasts

Bacterial infections are a potent mechanism for enzymatic generation of kinins such as bradykinin (BK), a universal mediator for inducing inflammatory reaction by associating with the B2 receptor and stimulating liberation of arachidonic acid and synthesis of prostaglandin E2 (PGE2). In this study we evaluate the role of bradykinin in regulating the expression of TLR4 receptor in human gingival fibroblasts. We examine the ability of bradykinin to modulate inflammatory response of human gingival fibroblasts to Gram-negative components and evaluated the role of Toll-like receptors (TLR)-4 in the co-operation between bradykinin and bacterial pathogens. We show that treatment with bradykinin promotes TLR4 receptor expression in human gingival fibroblasts (HGF) and amplifies inflammatory responses to the bacterial components of Gram-negative bacteria. The TLR4 expression induced by bradykinin was blocked with Hoe 140, a B2R antagonist. When HGF cells were incubated with BK resulted of an increased in cyclooxygenase-2 (COX-2) expression and prostaglandin E2 synthesis. Bradykinin and lipopolysaccharide, a specific TLR4 ligand stimulated COX-2 expression. In other series of experiments we found that ERK, phosphatidylinositol-3 kinase, protein kinase C and NFkB are involved in BK promoted-increased in TLR4 expression. The results demonstrate that bradykinin up-regulates the expression of TLR4 and promotes an additive increase in inflammatory responses to lipopolysaccharides.

Prevalence and risk indicators of gingivitis and periodontitis in a multi-centre study in North Jordan: a cross sectional study

Background

There are limited data about the epidemiology and risk factors/indicators of gingivitis, aggressive periodontitis (AgP) and chronic periodontitis (CP) in Jordan. The aim of this study was to assess the prevalence and risk indicators of gingivitis, AgP and CP.

Methods

A sample of 595 subjects was randomly selected from subjects escorting out-patients attending a Medical Center, a Dental Teaching Hospital, and 2 private dental clinics. The socio-demographic variables, oral hygiene habits, income, smoking and Body Mass Index (BMI) were recorded. Full mouth periodontal examination was performed, and radiographs were taken for sites with probing depth > 3 mm.

Results

About 76% had gingivitis, 2.2% had AgP and 5.5% had CP. Periodontitis was more frequent among males than females with a M: F ratio of 1.6:1 and the prevalence increased with age. Subjects who reported not using a tooth brush, smokers and subjects with BMI > 30 kg/m² had significantly higher prevalence of periodontitis. The risk for periodontitis was greater among subjects who reported positive family history and subjects with ≤ 12 years of education.

Conclusions

This is the first study to report on the prevalence of gingivitis, CP and AgP in North Jordanian. Age, low education, low frequency of tooth brushing and family history were significantly associated with increased risk of periodontitis.

Gene polymorphisms in chronic periodontitis

We aimed to conduct a review of the literature for gene polymorphisms associated with chronic periodontitis (CP) susceptibility. A comprehensive search of the literature in English was performed using the keywords: periodontitis, periodontal disease, combined with the words genes, mutation, or polymorphism. Candidate gene polymorphism studies with a case-control design and reported genotype frequencies in CP patients were searched and reviewed. There is growing evidence that polymorphisms in the IL1, IL6, IL10, vitamin D receptor, and CD14 genes may be associated with CP in certain populations. However, carriage rates of the rare (R)-allele of any polymorphism varied considerably among studies and most of the studies appeared under-powered and did not correct for other risk factors. Larger cohorts, well-defined phenotypes, control for other risk factors, and analysis of multiple genes and polymorphisms within the same pathway are needed to get a more comprehensive insight into the contribution of gene polymorphisms in CP.

Humoral immune response to antigens of Porphyromonas gingivalis ATCC 33277 in chronic periodontitis

Introduction:

Periodontitis is a chronic disease that results from an interaction of a mixed bacterial challenge and the host response.

Objective:

The purposes of this study were to evaluate the IgG serum levels to Porphyromonas gingivalis antigens by ELISA in individuals with different periodontal conditions correlated with clinical parameters, and to analyze the immunoreactivity profiles by Western blotting.

Methods:

Serum IgG levels against the cell sonicate antigen from P. gingivalis ATCC 33277 of 28 patients with chronic periodontitis (CP), 10 patients with gingivitis (G) and 21 periodontally healthy individuals (H) were measured by ELISA and Western immunoblotting.

Results:

In the CP group, sera reactivity by ELISA was significantly higher than in the G and H groups (Kruskal-Wallis p<0.001; Dunnet t3 p= 0.001 and Dunnet t3 p= 0.0001). There was no statistically significant difference between G and HP reactivity (Dunnett t3 p=0.617). Among individuals with chronic periodontitis, the IgG-anti-P. gingivalis serum levels were positively correlated with percentage of clinical attachment level =5mm (r_s = + 0.375, p<0.05) and a negative correlation was found between IgG-anti-P. gingivalis levels and percentage of probing pocket depth 0-3mm (r_s = - 0. 411, p< 0.05). The analysis of sera immunoreactivity profiles to sonicate antigen by Western blotting showed differences between the sera of CP, G and H group individuals. The serum from CP frequently reacted with high molecular weight (103 kDa, 86 kDa, 72 kDa, 60 kDa, 58 kDa, 52 kDa) protein fractions.

Conclusions:

Serum levels of IgG anti-P. gingivalis distinguished individuals with chronic periodontitis, gingivitis and healthy periodontium. There was a correlation between clinical parameters and serum IgG levels against P. gingivalis. There was a difference in the recognition profile of protein fractions among the studied groups and some bands were more specific

The effects of tetracycline, minocycline, doxycycline and ofloxacin on Prevotella intermedia biofilm

Prevotella intermedia, a black-pigmented, anaerobic, gram-negative bacterium, is associated with various type of periodontitis. Antibiotic treatments via a systemic or local route have been reported as being useful for treating periodontal disease. The purpose of this study was to examine the effects of four antibiotics, tetracycline (TET), minocycline (MINO), doxycycline (DOXY) and ofloxacin (OFLX) on P. intermedia biofilms at minimum inhibitory concentrations (MIC) from one-fold to 100-fold. MICs were determined for planktonic cells. Biofilm formation was determined with the crystal violet stain method and the bioactivities in the biofilms were determined with the adenosine triphosphate (ATP) -bioluminescent assay using a 96-well culture plate. At one-fold MIC, DOXY inhibited biofilm formation by P. intermedia ATCC 25611. Other antibiotics at one-fold MIC had no effects on the biofilm formation of tested bacterial strains. In P. intermedia ATCC 25611 biofilms, all the antibiotics tested showed inhibitory activities at five- to 100-fold MICs. In the biofilms of P. intermedia strains, except ATCC 25611, treated with three tetracycline antibiotics, the bioactivities were significantly increased, indicating the difficulties involved in designing antibiotic therapy for periodontal disease.

Benefit of “one-stage full-mouth disinfection” is explained by disinfection and root planing within 24 hours: a randomized controlled trial

OBJECTIVES

The beneficial effects of the one-stage, full-mouth disinfection remain controversial in the scientific literature. This might be due to the fact that an entire mouth disinfection with the use of antiseptics has been confused with a full-mouth scaling and root planing. This parallel, single blind RCT study aimed to compare several full-mouth treatment strategies with each other.

MATERIAL AND METHODS

Seventy-one patients with moderate periodontitis were randomly allocated to one of the following treatment strategies: scaling and root planing, quadrant by quadrant, at two-week intervals (negative control, NC), full-mouth scaling and root planing within 2 consecutive days (FRP), or three one-stage, full-mouth disinfection (FM) protocols within 2 consecutive days applying antiseptics to all intra-oral niches for periopathogens using as antiseptics: chlorhexidine (FMCHX) for 2 months, amine fluoride/stannous fluoride for 2 months (FMF), or chlorhexidine for 2 months followed by amine fluoride/stannous fluoride for another 6 months (FMCHX+F). At baseline and after 2, 4, and 8 a series of periodontal parameters were recorded.

RESULTS

All treatment strategies resulted in significant (p<0.05) improvements of all clinical parameters over the entire duration of the study. Inter-treatment differences were often encountered. The NC group nearly always showed significant smaller improvements than the two CHX groups. The differences between the FRP or FM groups, and the two CHX groups only sporadically reached a statistical significance.

CONCLUSION

These observations indicate that the benefits of the "OSFMD" protocol are partially due to the use of the antiseptics and partially to the completion of the therapy in a short time.

Tongue coating and tongue brushing: a literature review

The present paper reviews the role of the tongue as a habitat for oral microorganisms and the potential need for tongue cleaning as part of daily oral hygiene. In addition tongue coating is described. Many microorganisms have been found colonizing the dorsum of the tongue. Some studies find a positive effect to tongue brushing on bacterial counts on the tongue. On the other hand there are also studies that do not find any differences in bacterial counts before or after tongue brushing. Bacteria colonizing the tongue and periodontal pockets play an important role in the production of volatile sulphur compounds in periodontal health and disease. These compounds can be the cause of oral malodour. The amount of tongue coating in patients complaining of halitosis was significantly greater than in patients without halitosis. Tongue brushing on a regular basis, particular aiming at removing the coating on the dorsum of the tongue, has been found to be fruitful in reducing oral malodour. Studies investigating the role of tongue brushing and plaque accumulation or gingival inflammation show conflicting results. It is clear that the tongue forms the largest niche for microorganims in the oral cavity. However, on the basis of literature, there appears to be no data to justify the necessity to clean the tongue on a regular basis. One exception would be oral malodour.

Dynamics of initial subgingival colonization of ‘pristine’ peri-implant pockets

BACKGROUND

Periodontitis and peri-implantitis are linked to the presence of several key pathogens. The treatment of these infectious processes therefore involves the reduction/eradication of bacteria associated with periodontitis.

METHODS

This prospective, split-mouth, single-blind study followed the colonization of 'pristine' sulci created in 42 partially edentulous patients during implant surgery (e.g. abutment connection). The hypothesis was that the composition of the maturing subgingival plaque in these 'fresh' peri-implant pockets would soon (within 2 weeks) be comparable to the subgingival microbiota of teeth with similar clinical parameters (reference sites), including the presence of bacteria associated with periodontitis. Per patient, four subgingival plaque samples were taken from shallow and medium pockets around implants (test sites), and teeth within the same quadrant (undisturbed microbiota as control sites), 1, 2, 4, 13, 26 and 78 weeks after abutment connection, respectively. The samples were analysed by either checkerboard DNA-DNA hybridization, or cultural techniques, or real-time polymerase chain reaction (PCR) for intra-subject comparisons (teeth vs. implant, for comparable probing depths).

RESULTS

Checkerboard DNA-DNA hybridization and real-time PCR revealed a complex microbiota (including several pathogenic species) in the peri-implant pockets within 2 weeks after abutment connection. After 7 days, the detection frequency for most species (including the bacteria associated with periodontitis) was already nearly identical in samples from the fresh peri-implant pockets (5% and 20% of the microbiota belonging to red and orange complex, respectively) when compared with samples from the reference teeth. Afterwards (e.g. between weeks 2 and 13), the number of bacteria in peri-implant pockets only slightly increased (+/-0.1 log value), with minor changes in the relative proportions of bacteria associated with periodontitis (8% and 33% of the microbiota belonging to red and orange complex, respectively). Although small differences were seen between teeth and implants at week 2 with cultural techniques, a striking similarity in subgingival microbiota was found with this technique from month 3 on, with nearly identical detection frequencies for bacteria associated with periodontitis for both abutment types.

CONCLUSIONS

This study indicates that the initial colonization of peri-implant pockets with bacteria associated with periodontitis occurs within 2 weeks.

Identification of genetic risk factors for periodontitis and possible mechanisms of action

AIM

To review the literature for genetic risk factors associated with periodontitis.

METHODS

Computerized search of the literature in English using key words: Periodontitis; Genes; Mutation; Polymorphism; Risk.

RESULTS AND CONCLUSIONS

Mutations in the cathepsin C gene (CTSC) have been identified as causal for the Papillon-Lefèvre syndrome (PLS), which includes prepubertal periodontitis (PP). Some CTSC mutations are causal for PP without PLS. No relationship has been demonstrated between CTSC mutations and other forms of periodontitis. Genetic polymorphisms in a candidate gene approach have been explored as risk factors for periodontitis. There is limited evidence that some polymorphisms in the genes encoding interleukins (IL)-1, Fc gamma receptors (Fc gammaR), IL-10 and the vitamin D receptor, may be associated with periodontitis in certain ethnic groups. However relatively large variations in carriage rates of the Rare (R)-alleles among studies on any polymorphism were observed. The available studies appear under-powered and do not adequately take into account other pertinent risk factors for periodontitis. Future studies should include larger cohorts, should clearly define phenotypes and should adequately control for other risk factors. In addition to the candidate gene approach, alternative strategies need to be considered to elucidate the gene variations, which confer risk for periodontitis.

IgG antibody levels to Porphyromonas gingivalis and clinical measures in children

BACKGROUND

Periodontopathic clinical markers are poorly understood in the pediatric population. Several studies have proposed Porphyromonas gingivalis (P. gingivalis) and an antibody response to the microorganism as factors in periodontal tissue destruction in children. The objective of this study was to examine the prevalence of P. gingivalis in dental plaque and of serum immunoglobulin G (IgG) antibody levels to P. gingivalis, and their relationship to periodontal clinical measures in children.

METHODS

Thirty-one subjects, aged 20 to 163 months, participated in this study. Clinical measures examined included gingivitis, plaque, alveolar bone height, age, gender, ethnicity, medical status, caries, and IgG antibody levels to P. gingivalis. Five ml of blood was collected for serum analysis, and IgG antibody levels to P. gingivalis were determined by using enzyme-linked immunosorbent assay. Plaque samples were examined for the presence of P. gingivalis by DNA-DNA checkerboard. Data were analyzed on a person-level basis for relationships to serum IgG antibody levels to P. gingivalis and on a site-specific level for relationships to the presence of P. gingivalis in plaque.

RESULTS

A majority (77%) of the subjects were systemically healthy, non-white (74%), and did not have detectable P. gingivalis in their plaque. Fifty-two percent of the subjects had positive serum IgG antibody levels to P. gingivalis. Based on univariate linear regression, factors related to IgG antibody levels to P. gingivalis (P<0.05) included age, average gingival index (GI), average probing depth, and number of teeth with alveolar bone crest to cemento-enamel junction (ABC-CEJ) distances >2 mm. When all clinical measures were considered together, only age remained statistically significantly related to serum IgG antibody levels to P. gingivalis.

CONCLUSIONS

Age is one of the most important factors in the development of the immune response to putative microorganisms such as P. gingivalis in children. The role of IgG as a time-sensitive measure of periodontal health in children needs to be investigated further.

Increased release of IL-12p70 by monocytes after periodontal therapy

OBJECTIVES

It has been suggested that periodontal inflammation may result in an altered immune response. The peripheral immune capacity in periodontitis patients can be investigated using lipopolysaccharide (LPS)-stimulated whole blood cell cultures (WBCC), known to reflect the behavior of monocytes in particular. A previous study in our laboratory revealed that monocytes in the stimulated cultures from periodontitis patients behaved functionally different compared with controls. The present study investigated whether this different response of periodontitis patients' monocytes is intrinsic or acquired.

MATERIAL AND METHODS

The release of inflammatory mediators was measured in Escherichia coli LPS-stimulated WBCC from 12 periodontitis patients before and after periodontal therapy. In addition, the total leukocyte and leukocyte differentiation counts were also determined in the patients before and after therapy.

RESULTS

The levels of interleukin (IL)-12p70 in cell culture supernatants increased two times and those of prostaglandin E2 showed a trend towards reduction after therapy, whereas the levels of IL-1beta, IL-6, IL-8, IL-10, IL-12p40 and tumor necrosis factor-alpha did not change. The total number of white blood cells was decreased after periodontal therapy.

CONCLUSIONS

After periodontal therapy, the functional phenotype of the peripheral blood monocytes from patients was reconstituted, resembling that of subjects without periodontitis.

Intra-familial distribution of nine putative periodontopathogens in dental plaque samples analyzed by PCR

It is of great importance to understand the distribution of periodontopathogens within family members when considering the risk of periodontitis in children. The purpose of this study was to investigate the distribution of periodontopathogens among family members. We used the polymerase chain reaction method to test 4,8, and 7 probands with healthy gingiva, gingivitis, and periodontitis, respectively, and their 60 immediate family members. Plaque samples were collected from all erupted teeth sites using a sterile toothbrush. In 161 of the 165 positive cases, if a child harbored one of the periodontopathogens then at least one of the parents was also positive for the same bacterium. The prevalence of parent-child co-infection was 42.9% for Actinobacillus actinomycetemcomitans, 21.4% for Porphyromonas gingivalis, 29.2% for Treponema denticola, 59.5% for Tannerella forsythensis (Bacteroides forsythus) and 16.7% for Prevotella intermedia. Our results indicate that parents could be an important source of periodontopathogens for the colonization that occurs in their children.

Microbial shifts after subgingival debridement and formation of bacterial resistance when combined with local or systemic antimicrobials

Antibiotics have played a major role in the improvement of life expectancy in the last 50 years and have led many to believe that bacterial infections were about to vanish as a disease entity of any importance. Emerging problems resulting from a widespread use of antibiotics have modified the general perception of the capabilities of antimicrobial agents. Over the years, bacteria have become increasingly resistant to formerly potent antimicrobial agents, including some antiseptics. The use of antimicrobials may also disturb the delicate ecological equilibrium of the body, allowing the proliferation of resistant bacteria or non-bacterial micro-organisms. This shift may initiate new infections that are worse than the ones originally treated. No antimicrobial drug is absolutely non-toxic and the use of an agent carries accompanying risks. This paper discusses the development and occurrence of antimicrobial resistance in the subgingival flora towards antiseptics and local or systemic antibiotics and is focussed on the question: how can the outcome of periodontal therapy with/without antimicrobials be improved?

Relationship Between Transmission ofPorphyromonas gingivalisandfimAType in Spouses

BACKGROUND

Porphyromonas gingivalis is one of the major microbial pathogens associated with chronic periodontitis. To eradicate such pathogens by periodontal therapy, it is essential to clarify the source of infection. Recent findings suggest that the genotype of the fimbriae is one of the important factors in infection by P. gingivalis. The objectives of the present study were to investigate the transmission of P. gingivalis between spouses and to determine the relationship between P. gingivalis fimA type and colonization.

METHODS

A total of 14 couples were selected to investigate the transmission of P. gingivalis and its association with the fimA types. To examine the distribution of fimA type in the general population, 32 subgingival plaque samples from 47 patients with periodontitis were also tested. The transmission of P. gingivalis strains was determined by using pulsed field gel electrophoresis (PFGE). P. gingivalis strains isolated from the couples and subgingival dental plaque samples were studied for fimA classification.

RESULTS

The PFGE patterns of P. gingivalis strains from matched husbands and wives were identical for six of the 14 couples. In five of these six couples (83.3%), P. gingivalis strains harboring the type II fimA gene were present. The proportion of type II fimA in the strains isolated from couples with probable intrafamilial transmission was significantly higher than that in patients with periodontitis or in the group of samples isolated from one member of a couple.

CONCLUSION

This study suggests that fimA type II, even though widely distributed in patients with periodontitis, may be an important factor in the transmission of P. gingivalis between spouses.

Monocyte-derived RANTES is intrinsically elevated in periodontal disease while MCP-1 levels are related to inflammation and are inversely correlated with IL-12 levels

Bacteria colonizing tooth surfaces are essential in the induction of an inflammatory response in the periodontal tissues, but do not cause periodontitis in everyone, implicating differences in the host immune response. These possible differences were studied using lipopolysaccharide (LPS)-stimulated whole blood cell cultures (WBCC), which revealed a down regulation of monocyte derived interleukin-12 (IL-12p70) in untreated periodontitis patients and an up regulation after therapy. IL-12p70 is a crucial factor in the differentiation of Th1 cell responses. Since CC chemokines are able to influence the T cell differentiation via cytokine secretion in antigen-presenting cells, the production of CC chemokines in periodontitis was evaluated. Therefore WBCC were stimulated with LPS from Escherichia coli for 18 h and the levels of IL-12p70 and CC chemokines were measured in the supernatants by ELISA. Untreated periodontitis patients released 2 fold more RANTES (regulated on activation normal T cell expressed and secreted) (P = 0.01) and lower levels of IL-12p70 in comparison to controls (P < 0.05). A trend towards higher levels of macrophage chemoattractant protein-1 (MCP-1) (P = 0.07) was also seen in untreated periodontitis patients; while similar levels of monocyte derived chemokine (MDC) and macrophage inflammatory proteins-1 alpha and -1 beta (MIP-1 alpha and -1 beta) were found. After periodontal therapy no changes were seen with regard to MDC, MIP-1 alpha, MIP-1 beta and RANTES, whereas the MCP-1 levels decreased (P < 0.05) and the IL-12p70 levels strongly increased (P < 0.01). The data showed a consistent inverse correlation between the levels of MCP-1 and IL-12p70, and their proportional changes after therapy correlated with the clinical inflammatory response after therapy. This indicates that the disease state regulates the release of IL-12p70 and MCP-1 in E. coli LPS-stimulated WBCC. In contrast, the persistent augmented levels of RANTES after therapy are suggestive for an intrinsic behaviour.

Similarity of the oral microbiota of pre-school children with that of their caregivers in a population-based study

This study evaluated the similarity between the oral microbiota of young children and that of their adult caregivers. Oral samples from children (174 dentate and 18 pre-dentate) aged 6-36 months and their caregivers in Saipan were assayed using a DNA probe assay. Many species including Streptococcus mutans, Streptococcus sobrinus, Actinomyces species, Campylobacter rectus, Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis were detected in dentate and pre-dentate children, whereas Bacteroides forsythus was detected only in dentate children. A higher percentage of children were positive for the detection of an individual species if the caregiver was also positive. There were significant relative risks of species detection between dentate children and their caregivers. By logistic regression, there were significant positive associations between species detection in caregiver and in child, but not between species detection and child age or maternal education level. In conclusion, dental pathogens were detected in young, including pre-dentate, children. The microbial profiles of children were strongly associated with the microbiota of their caregivers.

Periodontopathogens in the saliva and subgingival dental plaque of a group of mothers

The aim of this study was to assess the periodontal condition and the presence of putative periodontal pathogens in 30 Brazilian mothers, aging 21-40 years (28.4 4.49 years), and in their children, aging 5-6 years, since mothers can be a source of pathogens and, thus, influence their children's bacteriological and clinical condition. Besides assessing the plaque index (PI), gingival index (GI) and pocket probing depth (PD), the survey analyzed four subgingival dental plaque samples from mothers and children, as well as a sample of stimulated saliva from mothers. Those samples were analyzed by means of the slot immunoblot (SIB) technique, in order to determine the presence of Actinobacillus actinomycetemcomitans (Aa), Prevotella nigrescens (Pn), Porphyromonas gingivalis (Pg) and Treponema denticola (Td). The mean values and standard deviations of the evaluated clinical variables for mothers and children were, respectively: 1.86 0.67 and 1.64 0.68 for PI, and 1.24 0.67 and 0.82 0.37, for GI. Only for mothers, the total PD was 1.81 0.69 mm, and the PD of four sites was 4.03 1.40 mm. The Wilcoxon test revealed significant difference (p < 0.05) between mothers and their children only as to GI. The most prevalent bacteria in mothers were, in decreasing order: Aa, Pn, Pg and Td. The children presented patterns of oral hygiene and bacterial profiles similar to those of their mothers, in spite of the fact that most of them did not present enough subgingival plaque for testing. The comparison between mothers' subgingival dental plaque and saliva samples revealed statistically significant differences (p < 0.05) for all bacteria, with greater positivity and scores in the saliva, which demonstrates that it is an indicator of oral colonization and can work as a vehicle for the transmission of periodontopathogens from mothers to their children.

Periodontal pathogen detection in gingiva/tooth and tongue flora samples from 18- to 48-month-old children and periodontal status of their mothers

Few studies have detected periodontal pathogens in young children, and when detected the prevalence has been relatively low. In this epidemiological study, we determined the prevalence of periodontal pathogen colonization in young children and examined the relationship between periodontitis in mothers and detection of periodontal pathogens in their children aged 18-48 months. Children were selected and enrolled randomly into the study; tongue and gingival/tooth plaque samples were harvested and analyzed by DNA probe checkerboard assay for Porphyromonas gingivalis and Bacteroides forsythus. Clinical measurements included a gingival bleeding score in the children and a periodontal screening and recording (PSR) score in the mothers. Mothers having one or more periodontal sites with probing depths > 5.5 mm were classified as having periodontitis. In this population, 71% (66/93) of the 18- to 48-month-old children were infected with at least one periodontal pathogen. Detection rates for children were 68.8% for P. gingivalis and 29.0% for B. forsythus. About 13.8% (11/80) of children had gingival bleeding in response to a toothpick inserted interproximally. Children in whom B. forsythus was detected were about 6 times more likely to have gingival bleeding than other children. There was no relationship between bleeding and detection of P. gingivalis. 17.0% (16/94) of the mothers had periodontitis. When all mother-child pairs were considered, the periodontal status of the mother was found not to be a determinant for detection of periodontal pathogens in the floral samples from the children. However, the odds ratio that a daughter of a mother with periodontitis would be colonized was 5.2 for B. forsythus. A much higher proportion of children in this population were colonized by P. gingivalis and/or B. forsythus than has been previously reported for other populations. A modest level of association between manifestations of periodontitis in mothers and detection of B. forsythus in their daughters was observed.

Infectious risks for oral implants: a review of the literature

The use of oral implants in the rehabilitation of partially and fully edentulous patients is widely accepted even though failures do occur. The chance for implants to integrate can for example be jeopardised by the intra-oral presence of bacteria and concomitant inflammatory reactions. The longevity of osseointegrated implants can be compromised by occlusal overload and/or plaque-induced peri-implantitis, depending on the implant geometry and surface characteristics. Animal studies, cross-sectional and longitudinal observations in man, as well as association studies indicate that peri-implantitis is characterised by a microbiota comparable to that of periodontitis (high proportion of anaerobic Gram-negative rods, motile organisms and spirochetes), but this does not necessarily prove a causal relationship. However, in order to prevent such a bacterial shift, the following measures can be considered: periodontal health in the remaining dentition (to prevent bacterial translocation), the avoidance of deepened peri-implant pockets, and the use of a relatively smooth abutment and implant surface. Finally, periodontitis enhancing factors such as smoking and poor oral hygiene also increase the risk for peri-implantitis. Whether the susceptibility for periodontitis is related to that for peri-implantitis may vary according to the implant type and especially its surface topography.

A type 2 response in lipopolysaccharide (LPS)-stimulated whole blood cell cultures from periodontitis patients

It is acknowledged that periodontitis results from the interaction of the host immune response with bacteria accumulating on the tooth surfaces. Although bacteria are essential, they are insufficient to cause the disease. Despite this knowledge it remains unclear why certain individuals are more susceptible to periodontitis than others. Therefore the present study investigated whether differences exist in the actual immune response between periodontitis patients and controls after stimulation of peripheral blood cells. Whole blood cell cultures (WBCC) were stimulated with LPS from Escherichia coli during 18 h and the release of prostaglandin E2 (PGE2), IL-1beta, IL-6, IL-8, IL-10, IL-12p40, IL-12p70 and tumour necrosis factor-alpha (TNF-alpha) was measured. The levels of PGE2 were two-fold higher in the WBCC from periodontitis patients than from controls. In contrast, the levels of IL-12p70 in WBCC from patients were two-fold lower. Furthermore, WBCC from patients secreted lower levels of IL-1beta and higher levels of IL-8 when compared with WBCC from controls. No differences were observed with respect to IL-6, IL-10, IL-12p40 and TNF-alpha production. It is known from the literature that LPS-stimulated WBCC reflect specifically the behaviour of the monocytes and that monocytes are peripheral precursors of antigen-presenting cells (APC). Therefore it is concluded that the monocytes in the present WBCC from periodontitis patients are responsible for the higher levels of PGE2 and lower levels of IL-12p70. Since it is has been shown that APC-derived IL-12p70 induces type (Th1) cells that promote cellular immunity, while APC-derived PGE2 induces type 2-helper (Th2) cells that promote humoral immunity, it is postulated that APC from periodontitis patients may have a bias in directing Th2 responses and thereby promoting the humoral immunity in periodontitis.

The intra-oral translocation of periodontopathogens jeopardises the outcome of periodontal therapy

BACKGROUND

Although periodontitis has a multi-factorial aetiology, the success of its therapy mainly focuses on the eradication/reduction of the exogenous/endogenous periodontopathogens. Most of the species colonise several niches within the oral cavity (e.g. the mucosae, the tongue, the saliva, the periodontal pockets and all intra-oral hard surfaces) and even in the oro-pharyngeal area (e.g., the sinus and the tonsils).

METHODS

This review article discusses the intra-oral transmission of periodontopathogens between these niches and analyses clinical studies that support the idea and importance of such an intra-oral translocation.

RESULTS AND CONCLUSIONS

Based on the literature, the oro-pharyngeal area should indeed be considered as a microbiological entity. Because untreated pockets jeopardise the healing of recently instrumented sites, the treatment of periodontitis should involve "a one stage approach" of all pathologic pockets (1-stage full-mouth disinfection) or should at least consider the use of antiseptics during the intervals between consecutive instrumentations, in order to prevent a microbial translocation of periodontopathogens during the healing period. For the same reason, regeneration procedures or the local application of antibiotics should be postponed until a maximal improvement has been obtained in the remaining dentition. This more global approach offers significant additional clinical and microbiological benefits.

Genetic competence and transformation in oral streptococci

The oral streptococci are normally non-pathogenic residents of the human microflora. There is substantial evidence that these bacteria can, however, act as "genetic reservoirs" and transfer genetic information to transient bacteria as they make their way through the mouth, the principal entry point for a wide variety of bacteria. Examples that are of particular concern include the transfer of antibiotic resistance from oral streptococci to Streptococcus pneumoniae. The mechanisms that are used by oral streptococci to exchange genetic information are not well-understood, although several species are known to enter a physiological state of genetic competence. This state permits them to become capable of natural genetic transformation, facilitating the acquisition of foreign DNA from the external environment. The oral streptococci share many similarities with two closely related Gram-positive bacteria, S. pneumoniae and Bacillus subtilis. In these bacteria, the mechanisms of quorum-sensing, the development of competence, and DNA uptake and integration are well-characterized. Using this knowledge and the data available in genome databases allowed us to identify putative genes involved in these processes in the oral organism Streptococcus mutans. Models of competence development and genetic transformation in the oral streptococci and strategies to confirm these models are discussed. Future studies of competence in oral biofilms, the natural environment of oral streptococci, will be discussed.

Tongue coating and salivary bacterial counts in healthy/gingivitis subjects and periodontitis patients

BACKGROUND

The papillary structure of the dorsum of the tongue forms a unique ecological site that provides a large surface area favoring the accumulation of oral debris and microorganisms. These micro-organisms of the tongue may be of influence on the flora of the entire oral cavity. The normal appearance of the dorsum of the tongue is either pinkish or has a thin white coating. For the present study a scoring method was developed to describe the appearance of the dorsum of the tongue in relation to the extent of color and thickness of tongue coating.

AIM

The purpose of this study was to investigate the discoloration and coating of the tongue in healthy/gingivitis subjects and periodontitis patients. Furthermore, to determine the relationship between the appearance of the tongue and the bacterial load in salivary samples.

MATERIAL AND METHODS

2 groups of patients were studied, 70 healthy/gingivitis subjects and 56 periodontitis patients. After scoring of the tongue a salivary sample of each patient was taken and analyzed using a phase-contrast microscope.

RESULTS

This investigation showed that most discoloration was found on the distal part of the tongue. The mean number of bacteria per ml sample in relation to a pink, white and yellow appearance of the tongue was 948, 855 and 900 (x 10(6)) respectively. The mean number of bacteria per ml sample in relation to no, thin and thick coating was 948, 863, and 895 (x 10(6)), respectively. Analysis did not reveal a relationship between discoloration, coating thickness and total bacterial load. The mean number of bacteria per ml in healthy/gingivitis subjects was 860 and in periodontitis patients 918 (x 10(6)).

CONCLUSION

No relationship between the appearance of the tongue and salivary bacterial load could be detected. There was no difference in bacterial load between the healthy/gingivitis and the periodontitis group within the present study population.

The effects of toothpastes on the residual microbial contamination of toothbrushes

BACKGROUND

Contaminated toothbrushes have been shown to harbor and transmit viruses and bacteria. The authors conducted a study to evaluate the effect of a triclosan-containing toothpaste on the residual anaerobic microbial contamination of toothbrushes.

METHODS

Twenty patients who had Type III or Type IV periodontitis participated in this study. One side of each of their mouths served as a control (no toothpaste). The teeth on the other side were brushed with a regular toothpaste or a triclosan-containing toothpaste. After the toothbrushes were allowed to dry in air for four hours, the authors placed the toothbrush heads in solution, dislodged the microbes from the brushes by vortexing and plated them in culture dishes. The authors anerobically incubated the culture dishes and determined the presence or absence of Prevotella species or Ps; Porphyromonas gingivalis, or Pg; and Actinobacillus actinomycetemcomitans, or Aa.

RESULTS

The authors detected Aa and Pg on the control toothbrushes more frequently than they did Ps. This variation in isolation frequency was statistically significant by chi 2 analysis (P < .001). The authors compared the isolation frequency of the three test organisms between the control and regular-toothpaste groups, between the control and triclosan-containing--toothpaste groups, and between the triclosan-containing--toothpaste and regular-toothpaste groups. They found no significant intergroup differences in the isolation frequencies after using chi 2 analysis.

CONCLUSIONS

Toothpaste use reduced the residual microbial contamination for two of three test organisms, but the lower isolation frequencies were not statistically significant. Further study in this area is indicated.

CLINICAL IMPLICATIONS

Dental professionals should advise patients who have systemic, localized or oral inflammatory diseases to disinfect or frequently replace their toothbrushes.