The microbiota of periodontal pockets with different depths in therapy-resistant periodontitis

To Evaluate the Effect of Vitamin B Complex on Wound Healing - A Clinical and Microbiological Study

Background

The purpose of this study is to explore the effect of vitamin B complex supplementation following periodontal flap surgery on clinical and microbiological parameters.

Materials and Methods

A randomized controlled trial on 10 patients with periodontitis in split-mouth design was undertaken to find the effect of vitamin B complex supplementation with open flap debridement on periodontal wound healing. Multiplex polymerase chain reaction (PCR) for Tannerella forsythus and Porphyromonas gingivalis was done using subgingival plaque samples at 0 and 90th day.

Results

The results showed a significant reduction (P < 0.01) of clinical (plaque index, gingival index, gingival bleeding index, probing pocket depth, and relative attachment level) and microbial profile in both treatment groups, whereas on intergroup analysis, more reduction in all clinical parameters were observed in the test group, but statistically, the results were insignificant.

Presence of non-oral bacteria in the oral cavity

A homeostatic balance exists between the resident microbiota in the oral cavity and the host. Perturbations of the oral microbiota under particular conditions can contribute to the growth of non-oral pathogens that are hard to kill because of their higher resistance to antimicrobials, raising the probability of treatment failure and reinfection. The presence of these bacteria in the oral cavity has been proven to be associated with several oral diseases such as periodontitis, caries, and gingivitis, and systemic diseases of importance in clinical medicine such as cystic fibrosis, HIV, and rheumatoid arthritis. However, it is still controversial whether these species are merely transient members or unique to the oral cavity. Mutualistic and antagonistic interactions between the oral microbiota and non-oral pathogens can also occur, though the mechanisms used by these bacteria are not clear. Therefore, this review presents an overview of the current knowledge about the presence of non-oral bacteria in the oral cavity, their relationship with systemic and oral diseases, and their interactions with oral bacteria.

Prescribing trends of systemic antibiotics by periodontists in Australia

BACKGROUND

Antibiotics are a common systemic pharmaceutical therapy in periodontal conditions for dental practitioners as well as specialists. However, there is limited information about prescribing patterns amongst the periodontists within Australia. The objective of this study is to examine current patterns and perceptions in prescribing systemic antibiotics for the treatment of periodontal and peri-implant diseases.

METHODS

An online questionnaire was disseminated to Australian practicing members of the Australia and New Zealand Academy of Periodontists (ANZAP) to determine their antibiotic prescribing patterns for different periodontal conditions. Indications that were analyzed included: chronic periodontitis, plaque-induced gingivitis, aggressive periodontitis, acute gingival and periodontal conditions, conditions associated with implants and implant placement, periodontal regeneration, and mucogingival surgery.

RESULTS

Out of the 50 members that participated in the study, 38 completed the questionnaire. Systemic antibiotics prescription patterns varied markedly for different periodontal or peri-implant diseases among respondents. 79% reported prescription of systemic antibiotics in the treatment of chronic periodontitis whereas 52.6%, 55.3%, 18.4% of the respondents did so for periodontal regeneration procedures, implant placement surgery, and mucogingival surgery, respectively. Azithromycin, the combination of Amoxicillin and Metronidazole, and Amoxicillin were the three most commonly prescribed systemic antibiotics.

CONCLUSION

Based on the results of this survey, systemic antibiotics are widely used by the group of periodontists surveyed in this study in Australia with varying rates and patterns for different periodontal and peri-implant conditions. The current study highlights the need for recommendations and guidelines in the prescription of antibiotics for periodontal and peri-implant conditions.

Oral Candida colonization in patients with chronic periodontitis. Is there any relationship?

BACKGROUND

Candida can be implicated in the pathology of chronic periodontitis.

AIMS

To analyze the oral Candida carriage in patients suffering from chronic periodontitis (CP) and its correlation with the severity of this condition.

METHODS

Microbiological samples were taken from 155 patients using the oral rinse (OR) technique and by using paper points in the periodontal pockets (GPP). These patients were divided into 3 groups: 89 patients without CP (control), 47 with moderate CP, and 19 with severe CP. Samples were cultured in a Candida chromogenic agar for Candida. Species were identified by microbiological and molecular methods.

RESULTS

Candida was isolated in the OR of 45 (50.6%), 21 (44.7%), and 11 (57.9%) patients, respectively, and in the GPP of 32 (36%), 14 (29.2%), and 10 (42.6%) patients from the control, moderate CP and severe CP groups, respectively. Candida was isolated more frequently and in a greater burden in OR than in GPP (p<0.01). Candida albicans was the most prevalent species. GPP of patients with CP had poor fungal biodiversity (p<0.01).

CONCLUSIONS

Colonization by Candida was present in the samples of patients without CP, and with both moderate and severe CP. Nonetheless, patients with severe CP had a higher rate of Candida colonization, especially by C. albicans.

Subgingival prevalence rate of enteric rods in subjects with periodontal health and disease

BACKGROUND

The prevalence of enteric rods and their association with chronic periodontitis has gained prominence recently. Although the prevalence of these organisms from the subgingival plaque sample was reported in the literature, the carriage rate of these rods in our population is lacking. The present study was undertaken to know the carriage rate of enteric rods from our population in patients with periodontal health and disease.

MATERIALS AND METHODS

Eighty-four systemically healthy participants, inclusive of 46 males and 38 females, were selected for the study. The selected participants were subjected to a periodontal examination and were categorized into chronic periodontitis and healthy group. Subgingival plaque samples were taken from all the participants, plated onto McConkey agar plates, and incubated overnight at 37° C to check for the growth of organisms. The grown organisms were then cultured according to the standard procedures.

RESULTS

Prevalence of 71% and 83% of enteric rods in subjects with periodontal health and disease, respectively, was found in our study which was not statistically significant.

CONCLUSION

Although no significant differences exist in the prevalence of enteric rods between healthy and patients with chronic periodontitis, the prevalence rate of enteric rods in subgingival plaque samples is considerably high in our population.

Prevalence of subgingival Staphylococcus at periodontally healthy and diseased sites

Staphylococci are considered members of the transient oral microbiota and are seldom isolated from the oral cavity. The aim of this study was to establish the prevalence of subgingival staphylococci in healthy and periodontal disease sites. Sterile endodontic paper points were used to isolate subgingival staphylococci in periodontally healthy and periodontally diseased sites in 30 adult subjects (n=540 sites). Staphylococcus spp were identified by an automated method and confirmed by conventional biochemical tests. All the samples were identified as coagulase-negative staphylococci. The results were analyzed using Mann-Whitney U, chi-square and Fisher's exact test at 5% significance level. A total of 86.7% of the subjects harbored these microorganisms in 11.7% of their periodontal sites. The most frequently isolated species was S. auricularis, which was isolated from 31.4% of the periodontal sites, followed by S. epidermidis, isolated from 21.4% of them. There was no statistically significant difference between the frequencies of these species isolated either from the healthy and the diseased sites (p>0.153). Although staphylococci are present in the subgingival environment and contribute to the pathogenic synergism involved in periodontal diseases, the results suggest that they do not participate directly in the pathogenesis of these diseases.

Variation on a theme; an overview of the Tn916/Tn1545 family of mobile genetic elements in the oral and nasopharyngeal streptococci

The oral and nasopharyngeal streptococci are a major part of the normal microbiota in humans. Most human associated streptococci are considered commensals, however, a small number of them are pathogenic, causing a wide range of diseases including oral infections such as dental caries and periodontitis and diseases at other body sites including sinusitis and endocarditis, and in the case of Streptococcus pneumoniae, meningitis. Both phenotypic and sequence based studies have shown that the human associated streptococci from the mouth and nasopharynx harbor a large number of antibiotic resistance genes and these are often located on mobile genetic elements (MGEs) known as conjugative transposons or integrative and conjugative elements of the Tn916/Tn1545 family. These MGEs are responsible for the spread of the resistance genes between streptococci and also between streptococci and other bacteria. In this review we describe the resistances conferred by, and the genetic variations between the many different Tn916-like elements found in recent studies of oral and nasopharyngeal streptococci and show that Tn916-like elements are important mediators of antibiotic resistance genes within this genus. We will also discuss the role of the oral environment and how this is conducive to the transfer of these elements and discuss the contribution of both transformation and conjugation on the transfer and evolution of these elements in different streptococci.

Clinical evaluation of salivary periodontal pathogen levels by real-time polymerase chain reaction in patients before dental implant treatment

Objective

Periodontal pathogens in dental plaque are the main causative agents of periodontitis and peri-implantitis. Detection of the presence of such periodontal pathogens early would serve as a useful tool in the diagnosis and treatment of this disease. Therefore, the purpose of this study was to investigate whether the periodontal pathogen levels in saliva were correlated with the periodontal status of patients receiving implant treatment.

Materials and Methods

A total of 291 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: a no-periodontitis (np) group, a mild-periodontitis (mip) group, a moderate-periodontitis (mop) group, and a severe-periodontitis (sp) group. The levels of the following five periodontal pathogens in saliva were evaluated using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia.

Results

The levels of P. gingivalis and T. forsythia were significantly higher in mop group than in np group (P <  0.05). The levels of all periodontal pathogens tested except A. actinomycetemcomitans were significantly higher in sp group than in np group (P <  0.05).

Conclusion

The detection levels of the periodontal pathogens targeted in saliva samples were correlated with the periodontal status. This suggests that using saliva to screen for periodontopathic bacteria offers an easier-to-use clinical tool than the paper point method in the diagnosis and treatment of periodontitis and peri-implantitis.

Association of subgingival colonization of Candida albicans and other yeasts with severity of chronic periodontitis

BACKGROUND AND OBJECTIVE

The aim of this study is to analyze the relationship between the subgingival colonization by Candida albicans and other yeasts with the severity of chronic periodontitis (CP).

MATERIAL AND METHODS

After sample size calculation, 40 patients with CP and 20 healthy subjects (HS) were included in the study. Cases of slight-moderate (MCP, n = 23) and severe CP (SCP, n = 17) were defined according to the Centers for Disease Control/American Association of Periodontology classification. Subgingival samples were acquired using sterile paper-points from the sulcus or the deepest periodontal pocket of each healthy and subject with CP, respectively, and were cultured aerobically on three selective media. Yeast colonies that grew on the surface of plates were later identified by biochemical reactions. Statistical tests were used to analyze the association between subgingival yeast colonization (number of yeast-positive individuals and colony forming units (CFU) per subject) and periodontal disease status, considering statistical significance when P < 0.05.

RESULTS

Although several yeast species were found (C. parapisilosis, Rhodotorula sp., C. dubliniensis and C. tropicalis), only C. albicans was present in all the patients with yeast-positive CP. Twelve patients (30%) with CP presented yeasts in the subgingival biofilm while only three patients (15%) in the HS group were positive for these microorganisms. No statistical difference was found between the CP and HS groups (P = 0.084). However, when the CP group was divided on the basis of severity, statistical differences were observed between the SCP and MCP groups (47% vs. 17%, P = 0.043), and between the SCP and HS groups (47% vs. 15%, P = 0.033). No statistical difference was observed between the MCP and HS groups (17% vs. 15%, P = 0.832). High densities of yeasts were found only in patients with MCP and SCP (mean and range 61.25 (0-100) CFU/plate and mean and range 51 (0-101) CFU/plate, respectively).

CONCLUSION

In this group of patients, subgingival colonization of some yeasts, especially C. albicans, was associated with the severity of CP.

Microbiological basis for periodontal therapy

The search for the etiologic agents of periodontal diseases started in the Golden Era of medical bacteriology, when the etiologic agents of many bacterial infections were isolated and characterized. After the initial enthusiasm in establishing the infectious nature and the true agents of periodontal diseases, this concept was virtually ignored for the next four decades. Until the early 1970s treatment regimens based on the non-specific plaque hypothesis were directed towards a non-specific reduction in plaque amount. Later, the specific plaque hypothesis established the role of some microorganisms such as A. actinomycetemcomitans, P. gingivalis, T. forsythensis, T. denticola, P. intermedia and F. nucleatum in different forms of periodontal diseases. It was recently suggested that these suspected periodontal pathogens seem to not act alone and interactions between species, especially the balance between pathogenic and beneficial species affect both progression of disease and response of tissues to periodontal therapy. Nowadays it is well established that one of the goals of therapy is to control such periodontal pathogens. Among the most commonly used therapies to treat periodontal infections are scaling and root planing (SRP), supragingival plaque control and periodontal surgeries. Many studies confirmed the reduction of "red complex" species by SRP, and apically repositioned flap can lead to an additional beneficial effect in the subgingival microbiota by decreasing levels of "red" and "orange complexes" species. Furthermore, the level of plaque control maintained by the patients has been considered a crucial step in preventing recurrence of destructive periodontitis.

Relationship between Gram negative enteric rods, Aggregatibacter actinomycetemcomitans, and clinical parameters in periodontal disease

BACKGROUND

The association between Gram negative enteric rods and Aggregatibacter actinomycetemcomitans in periodontal diseases has received little attention in the literature. The objective of this study was to explore the relationship between these organisms and clinical parameters of periodontal disease.

MATERIALS AND METHODS

Clinical parameters and occurrence of Gram-negative enteric rods and A. actinomycetemcomitans were examined in 76 patients with chronic periodontitis. Chi-square and Mann-Whitney tests were used to determine differences in clinical variables versus the presence or absence of both microorganisms. Correlation among both organisms and clinical data were determined using Spearman rank correlation coefficient.

RESULTS

Gram-negative enteric rods and A. actinomycetemcomitans were detected in 20 (26.3%) and 18 (23.7%) individuals, respectively. A total of 14 (18.4%) patients harbored both microorganisms studied. There were significantly positive correlations between enteric rods and presence of A. actinomycetemcomitans (r=0.652, P<0.0001). Both microorganisms were significant and positively correlated with probing depth (PD), clinical attachment level, and bleeding on probing (P<0.0001). The mean PD (mm) of the sampled sites was significantly deeper in patients with presence of A. actinomycetemcomitans and Gram-negative enteric rods.

CONCLUSION

The results of the present study suggest a strong positive correlation between Gram-negative enteric rods and A. actinomycetemcomitans in the population studied. This finding must be taken into account when considering the best therapeutic approach, including the utilization of antimicrobials. The adverse clinical outcomes observed in presence of these microorganisms could have implications in the pathogenesis of periodontal disease and a possible impact on outcomes after treatment.

An efficient method for enumerating oral spirochetes using flow cytometry

Spirochetes, such as Treponema denticola, are thin walled, helical, motile bacteria. They are notoriously difficult to enumerate due to their thinness and the difficulties associated with culturing them. Here we have developed a modified oral bacterial growth medium (OBGM) that significantly improves the cultivation of T. denticola compared with a previously published growth medium. Three methods for the enumeration of T. denticola, semi-solid growth medium colony-forming unit (CFU) counts, DNA analysis and flow cytometry, are described and compared. Enumeration of T. denticola using the semi-solid agar method resulted in a positive linear relationship with absorbance of the culture (R(2)=0.9423). However, the semi-solid agar method was found to consistently underestimate (by 50 fold) the T. denticola cell density compared to previously published data. DNA analysis of T. denticola cultures reliably and consistently resulted in a positive linear relationship with absorbance (R(2)=0.9360), giving a calculated cell density of 6.9 x 10(8)cells/mL at an absorbance of 0.2 at 650 nm. Flow cytometry was also found to result in a positive linear relationship with absorbance (R(2)=0.9874), giving a calculated cell density of 6.6 x 10(8)cells/mL at an absorbance of 0.2 at 650 nm. In comparing all of these enumeration methods, the flow cytometry method was found to have distinct advantages, as it is accurate, rapid, and could distinguish between live and dead bacteria. Thus flow cytometry is a recommended means for the rapid and reliable enumeration of viable spirochetes from culture.

Clinical and microbiological determinants of ailing dental implants

BACKGROUND

The failure of the host tissue to establish or maintain osseointegration around dental implants is due to either occlusal or parafunctional forces, premature loading, ill-directed stress, or microbial infection. The long-term failure rate of dental implants is generally 5-10%. Although a variety of etiologies of early peri-implant bone loss (from implant placement to 1-year post-loading) have been proposed, factors associated with late implant failures are less well understood but are probably related to both the peri-implant microbial environment and host factors. Discriminating between causes of implant failure is of importance for instituting a successful implant therapy.

PURPOSE

The objective of this cross-sectional split-mouth study was to identify clinical, radiographic, and bacterial characteristics of peri-implant disease sites.

MATERIALS AND METHODS

Fifteen patients with bilateral implants (Brånemark, Nobel Biocare AB, Göteborg, Sweden; and 3i implant systems, Implant Innovations Inc., Palm Beach Gardens, FL, USA) participated in the study. Sites with peri-implant (radiographic bone loss beyond the third implant thread) and peri-implant healthy tissues (radiographic bone level above the first implant thread) were identified in periapical radiographs using a long-cone paralleling projection technique. Microbiological identification was carried out using established anaerobic culture techniques. A descriptive statistics based on means and standard deviations was reported.

RESULTS

Peri-implant bone loss was associated with the absence of radiographic crestal lamina dura, peri-implant pocket depth, pain on chewing, and the submucosal presence of the putative periodontopathogens Tannerella forsythia, Campylobacter species, and Peptostreptococcus micros. Pain was associated with P. micros, Fusobacterium species, and Eubacterium species.

DISCUSSION AND CONCLUSION

The absence of radiographic crestal lamina dura and the presence of suspected major periodontal pathogens seem to be associated to peri-implantitis.

Effect of adjunctive systemic azithromycin with periodontal surgery in the treatment of chronic periodontitis in smokers: a pilot study

BACKGROUND

Along with conventional surgical therapy, systemic antibiotics may provide more effective treatment in smokers by targeting tissue-invasive bacteria. The aim of this randomized, placebo-controlled, double-masked clinical trial was to evaluate the adjunctive effects of systemic azithromycin (AZM) in combination with periodontal pocket reduction surgery in the treatment of chronic periodontitis in smokers.

METHODS

Thirty patients with a greater than one pack/day smoking habit and generalized moderate to severe chronic periodontitis were randomized to the test (surgery plus 3 days of AZM, 500 mg) or control group (surgery plus 3 days of placebo). Full-mouth probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival index (GI), plaque index, and wound healing indices (WHI) were assessed at baseline and at 2 weeks and 1, 3, and 6 months following surgical intervention. Plaque and gingival crevicular fluid were collected for trypsin-like enzyme activity (benzoyl-dl-arginine naphthylamine) and bone biomarker (crosslinked telopeptide of type I collagen [ICTP]) analyses, respectively, at baseline, 2 weeks, and 1, 3, and 6 months.

RESULTS

Surgical treatment of moderate (PD = 4 to 6 mm) and deep (PD > 6 mm) pockets significantly improved clinical parameters of treated and untreated teeth (CAL gain, PD reduction, and reduction of BOP). The additional use of AZM did not enhance this improvement nor did it promote reduction of ICTP levels. Compared to the control group, the test group had significantly better WHI scores at 1 month, significantly less GI at 2 weeks, and sustained reductions of red-complex bacteria with trypsin-like enzyme activity at 3 months. For non-surgery teeth, only the test group showed significant gains in overall CAL compared to baseline.

CONCLUSIONS

The findings of this pilot study demonstrated that in heavy smokers, adjunctive systemic AZM in combination with pocket reduction surgery did not significantly enhance PD reduction or CAL gain. However, the clinical value of adjunctive AZM may be appreciated by more rapid wound healing, less short-term gingival inflammation, and sustained reductions of periopathogenic bacteria. More expanded studies are recommended to better determine the clinical effects of adjunctive AZM in patients who smoke.

Identification of periodontopathic bacteria in gingival tissue of Japanese periodontitis patients

INTRODUCTION

The identification of invading periodontopathic bacteria in tissues is important to determine their role in the pathogenesis of periodontal disease. The objective of this study was to identify periodontopathic bacteria in diseased gingival tissue of periodontitis patients.

METHODS

Subgingival plaque and gingival tissue were collected from 32 generalized chronic periodontitis (CP), 16 generalized aggressive periodontitis (GAgP) and eight localized aggressive periodontitis (LAgP) patients. Detection frequencies and quantities of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Tannerella forsythensis were investigated by polymerase chain reaction. The prevalences of Streptococcus oralis and Streptococcus sobrinus were also examined and the distribution of A. actinomycetemcomitans serotypes was observed.

RESULTS

P. gingivalis and T. forsythensis were detected in approximately 70% of tissue samples and 50% of plaque samples in the three periodontitis groups. Prevalence of A. actinomycetemcomitans in tissue samples was higher in the LAgP (63%) group than in either the CP (16%) or the GAgP (38%) group. A. actinomycetemcomitans serotype c was detected in 50% of LAgP patients. Detection frequencies of S. oralis and S. sobrinus were markedly low in both plaque and tissue samples from all three periodontitis groups. Amounts of P. gingivalis, A. actinomycetemcomitans and T. forsythensis in the tissue samples were not different among the three periodontitis groups.

CONCLUSION

P. gingivalis, A. actinomycetemcomitans and T. forsythensis can localize in diseased gingival tissue and may be involved in periodontal tissue destruction. Serotype c is the predominant serotype of A. actinomycetemcomitans in Japanese LAgP patients.

Effects of Vitamin-B Complex Supplementation on Periodontal Wound Healing

BACKGROUND

Reports have demonstrated that nutrient supplements, in particular vitamin-B complex (Vit-B), can positively influence wound healing processes. However, limited information is available on the effects of Vit-B on periodontal wound healing.

METHODS

A total of 30 patients (13 males, 17 females) presenting with generalized moderate to severe chronic periodontitis were enrolled in this study. All subjects presented > or = two teeth in the same sextant with probing depth (PD) > or =5 mm and bleeding upon probing (BOP) in need of access flap surgery (AFS). This study was a randomized, double-masked, placebo-controlled clinical trial. Subjects were instructed to take one capsule a day of either Vit-B (50 mg of the following: thiamine HCl, riboflavin, niacinamide, d-calcium pantothenate, and pyridoxine HCl; 50 microg each of d-biotin and cyanocobalamin; and 400 mcg of folate) or placebo for 30 days following AFS. Clinical attachment levels (CAL) and N-benzoyl-dl-arginine-2-naphthylamide (BANA) test scores were measured at baseline and at 90 and 180 days following surgical intervention. Assessments of the healing response were also performed using BOP, gingival index (GI), and plaque index (Pl) at baseline and 7, 14, 30, 90, and 180 days. The mean results of each parameter were averaged within a group. Differences between groups were analyzed by using repeated measures analysis of variance (ANOVA).

RESULTS

Both groups experienced comparable levels of PD reduction following AFS (test: -1.57 +/- 0.34; control: -1.50 +/- 0.21). Changes in mean CAL were more favorable in Vit-B supplemented subjects (test: +0.41 +/- 0.12; control: -0.52 +/- 0.23; P = 0.024). Stratified data demonstrated significantly better results for the test group in both shallow (test: -0.08 +/- 0.03; control: -1.11 +/- 0.27; P = 0.032) and deep sites (test: +1.69 +/- 0.31; control: +0.74 +/- 0.23; P = 0.037). No significant differences were observed between groups regarding PI, GI, and BOP. BANA test values were significantly reduced in both groups after surgical treatment and no significant differences were noted between groups.

CONCLUSION

Vitamin B-complex supplement in combination with AFS resulted in statistically significant superior CAL gains when compared to placebo.

Isolation and characterization of subgingival staphylococci from periodontitis patients and controls

OBJECTIVES

To isolate and characterize subgingival staphylococci from patients with periodontal disease and from periodontally healthy controls, to evaluate the periodontal environment as a potential source for systemic staphylococcal infections.

METHODS

Periopaper strips were used to isolate subgingival staphylococci from 28 patients with chronic periodontitis and 28 periodontally healthy age and sex-matched controls. Staphylococci were identified by microbiological methods and antibiotic resistance profiles determined.

RESULTS

Staphylococci were isolated from 54% diseased subgingival and 43% healthy subgingival sites in over 50% periodontitis patients and from 29% healthy subgingival sites in 54% controls. No significant differences in the frequency of isolation or numbers of staphylococci isolated from diseased and healthy sites were noted. Staphylococcus epidermidis was the predominant oral species. Seventy per cent (115 of 165) of all isolates were penicillin-resistant.

CONCLUSIONS

Subgingival staphylococci are present in both periodontitis patients and controls. In periodontitis there is an increased risk of bacteraemia because of the increased dentogingival surface area. The dental and periodontal health of patients at risk from haematogenous infections should therefore be maintained at a high level. Antibiotic resistance profiles of the oral staphylococcal isolates suggest that amoxicillin may no longer be a suitable antibiotic for prophylaxis against systemic infections such as prosthetic valve endocarditis.

Debridement and local application of tetracycline-loaded fibres in the management of persistent periodontitis: results after 12 months

BACKGROUNDS/AIMS

The aim of our study was to evaluate the clinical, radiological and microbiological response to the local delivery of tetracycline (TE) of sites with persistent periodontal lesions.

MATERIALS AND METHODS

The study was conducted in a split-mouth design. Nineteen patients with at least four bilateral pockets 4-5 mm and bleeding on probing (BOP) were treated with scaling and root planing (SRP) plus TE fibres (test sites) or with SRP alone (control sites). Clinical and radiological measurements were taken at baseline, 6 months and 12 months post-operatively. Subgingival plaque samples were collected at baseline, at fibres removal, 6 and 12 months following treatment and analysed by polymerase chain reaction.

RESULTS

Both treatments yielded a statistically significant (p<0.05) reduction of probing depth (2.05 and 1.21 mm), gain of clinical attachment level (1.71 and 0.53 mm) and reduction of BOP scores (23.68% and 57.89%) for TE and SRP groups, respectively, when comparing 12-month data with baseline. The differences between two groups were significant. The prevalence of Treponema denticola and Bacteroides forsythus decreased after therapy in both groups but only in the test sites Actinobacillus actinomycetemcomitans and Prevotella intermedia were not yield detected. The pathogens could be eliminated from five periodontal pockets by SRP alone, while 21 TE sites were not recolonized at 12 months.

CONCLUSIONS

SRP plus TE fibres gave the greatest advantage in the treatment of periodontal persistent lesions at least 12 months following treatment.

Specific Antibiotics in the Treatment of Periodontitis – A Proposed Strategy

BACKGROUND

The purpose of the present study was to propose a strategy for the selection of antibiotics that specifically target complexes of periodontal pathogens present in patients with periodontitis.

METHODS

Seven hundred seventy-four (774) patients with various forms of periodontitis were included in the study. Subgingival plaque samples were taken from the deepest periodontal pockets in each quadrant using a sterile curet, and pooled. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Tannerella forsythensis, Prevotella intermedia, and Prevotella nigrescens were identified by polymerase chain reaction, and the prevalence of combinations of these pathogens was determined. To each pathogen complex (PC), i.e., combination of pathogens, those antibiotics were assigned that were most specific according to the published minimum inhibitory concentration (MIC90) values and the gingival crevicular fluid (GCF) concentrations achievable in vivo. Antibiotic GCF concentrations had to be at least 10 times the MIC90 values, and the narrowest spectrum was selected with respect to the assessed periodontal pathogens.

RESULTS

Nine major PCs (each > or = 3% of all patients) were found in 73.4% of all patients, whereas 38 minor PCs (each < 3% of all patients) were distributed in 26.6% of all patients. Ten different antibiotic regimens were found to be specific for the total of 46 PCs; i.e., metronidazole and amoxicillin in 11 PCs (55.0% of all patients), metronidazole and amoxicillin/clavulanic acid or metronidazole and ciprofloxacin in 13 PCs (18.9%), amoxicillin in 4 PCs (8.3%), doxycycline in 2 PCs (6.1%), metronidazole in 8 PCs (4.1%), amoxicillin/clavulanic acid in 3 PCs (2.9%), clindamycin in 2 PCs (1.5%), ciprofloxacin in 2 PCs (0.4%), and tetracycline in 1 PC (0.3%).

CONCLUSION

The results of the study indicate that there are at least 46 different combinations of the assessed periodontal pathogens in subjects with periodontitis, and at least 10 different antibiotic regimens might be required to specifically target the various pathogen complexes.

Subgingival microbiota levels and their associations with periodontal status at the sampled sites in an adult Sudanese population using miswak or toothbrush regularly

Little information is available on the effect of miswak use on gingival microbiota. We assessed levels of 28 oral bacteria in subgingival plaque of adult Sudanese miswak (n = 38) and toothbrush users (n = 36) age range 20-53 years (mean 34.6 years) to study associations between these bacteria, oral hygiene method, and periodontal status at the sampled sites. A pooled subgingival plaque sample from 6 probing sites of 1 selected tooth in each jaw was obtained from each subject. Whole genomic DNA probes and the checkerboard DNA-DNA hybridization were used in assessing 74 pooled samples. Using 10(5) bacterial cells threshold, between 2.6% and 47.4% of miswak users and between 2.8% and 36.1% of toothbrush users harbored the investigated species. The percentages of subjects with the investigated species at 10(6) bacterial cells varied between 2.6% and 39.5% in miswak and between 2.8% and 36.1% in toothbrush users. Miswak users harbored significantly higher Streptococcus intermedius, Actinobacillus actinomycetemcomitans, Veillonella parvula, Actinomyces israelii, and Capnocytophaga gingivalis, and significantly lower Selenomonas sputigena, Streptococcus salivarius, Actinomyces naeslundii, and Streptococcus oralis than did toothbrush users. Probing pocket depth > or = 6 mm showed significantly (P < 0.05) higher levels of Porphyromonas gingivalis, Treponema denticola, Bacteroides forsythus, Fusobacterium nucleatum, and V. parvula than those 4-5 mm. Our results indicate that the type of oral hygiene had a significant effect on levels of 11 out of 28 bacterial species, and that the type of effect was also dependent on type of bacteria and probing pocket depth.

Bacterial adhesion to sulcular epithelium in periodontitis

The purpose of this study was to investigate, by electron microscopy, the type of bacterial attachment to the sulcular epithelium in periodontitis. Gingiva biopsies were observed in a transmission electron microscope using cytochemical staining with ruthenium red for glycocalyx visualisation. In addition, subgingival plaque samples and biopsies from the sulcular epithelium in periodontitis from the patients were estimated microbiologically. Aerobic bacteria only were estimated in the subgingival plaque and both aerobic and anaerobic bacteria in the gingival biopsies. No bacterial internalisation could be observed. Fimbria-mediated adhesion as the only type of bacterial attachment and a large diversity of bacterial glycocalyces were detected. As the fimbrial adhesins of putative periodontal pathogens are able in vitro to induce inflammation and bone resorption via stimulation of the proinflammatory cytokine production, the demonstrated fimbrial adhesins suggest the significant role of bacterial adhesion to sulcular epithelium in periodontitis.

Long-term follow-up of osseointegrated titanium implants using clinical, radiographic and microbiological parameters

The aim of this study was to longitudinally follow up osseointegrated titanium implants in partially dentate patients by clinical, radiographic and microbiological parameters in order to evaluate possible changes in the peri-implant health over time. Fifteen individuals treated with titanium implants, ad modum Brånemark, and followed for ten years were included in the study. Before implant placement ten years previously, the individuals had been treated for advanced periodontal disease and thereafter been included in a maintenance care program. The survival rate of the implants after ten years was 94.7%. The bone loss was 1.7 mm when using the abutment-fixture junction as a reference point. Of the individuals, 50% were positive for plaque at the implants. Bleeding on sulcus probing was present at 61% of the implant surfaces. Ten years previously, the individuals had been carriers of putative periodontal pathogens, such as Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Capnocytophaga spp. and Campylobacter rectus, and were also carriers of these species at the current examination. The results of the present study suggest that the presence of these putative periodontal pathogens at implants may not be associated with an impaired implant treatment. These species are most likely part of the normal resident microbiota of most individuals and may therefore be found at random at both stable and progressing peri-implant sites.

Bacteriocin production by Actinobacillus actinomycetemcomitans isolated from the oral cavity of humans with periodontal disease, periodontally healthy subjects and marmosets

The ability of Actinobacillus actinomycetemcomitans to produce bacteriocin has rarely been reported. Antagonistic substance production may confer an important ecological advantage for the producer microorganisms, especially in a competitive ecosystem such as the oral cavity. In the present study, 75 A. actinomycetemcomitans strains isolated from the oral cavity of human patients with periodontal disease, periodontally healthy subjects and marmosets, as well as two reference strains (A. actinomycetemcomitans ATCC 29523 and FDC Y4) were evaluated for auto-, iso-, and heteroantagonistic activity. Fifty-one (68.00%) strains exhibited antagonistic activity; heteroantagonism was observed more often than isoantagonism. Isolated strains antagonized 17 different species of gram-positive and gram-negative bacteria from the oral and nonoral microbiota. Sensitivity to heat and to proteolytic enzymes constituted strong evidence that the antagonistic substance has a proteic nature. Taken together, our data enabled us to confirm that the antagonistic substance detected was a bacteriocin. The wide spectrum of activity indicates the possibility that more than one antagonistic substance is produced and that these substances play an important role in the ecological balance of the oral ecosystem.

In vitro study of the effect of titanium on porphyromonas gingivalis in the presence of metronidazole and spiramycin

Septic peri-implantitis is the main clinical complication encountered following the insertion of titanium implants. It may be resistant to conventional antibiotic treatments. Reports in the literature about antibiotic behavior in the presence of titanium remain controversial. They vary from a bacteriostat to a decreased effect of antibiotic. This study examined, in vitro, the viability of Porphyromonas gingivalis, frequently associated with periodontal diseases, in the presence of titanium and antibiotics (spiramycin and metronidazole alone or in combination). Viability of P. gingivalis was determined, versus a standard curve using the Live/dead Baclight Bacteria Viability Kit on 96 well microplates. The results of 48 experiments (60 measurements each) were compiled in a database and compared to each other using the chi2p < 0.05 test. When used alone, titanium enhanced bacterial growth as the nickel-chrome control. However, when titanium was used in the presence of antibiotics, antibiotics kept their own effects. Even more, titanium was shown to potentialize the effect of metronidazole. The strengthening of effectiveness of metronidazole by titanium may be due to the oxidation potential of the metal. This chemical property could explain the conflicting data reported in the literature.

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

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

Performance of a commercial immunoassay for detection and differentiation of periodontal marker bacteria: analysis of immunochemical performance with clinical samples

BACKGROUND

We employed a commercial immunoassay for simultaneous detection and differentiation of marker bacteria Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia and reassessed the immunochemical performance of the assay.

METHODS

We compared the analytical performance of the immunoassay in our study of clinical samples from 249 periodontal patients in 2 private periodontal practices with the previously reported analytical performance of the same immunoassay. We also compared immunoassay measurements of the marker bacteria in clinical samples with values obtained in other studies by direct culture of the same organisms.

RESULTS

The assay produced 3 times more high-end readings than reported previously. We also reassessed and revised previously published calibration curves for the immunoassay. The immunoassay provided measurements of the marker bacteria in clinical samples from our patients that were comparable to and consistent with measurements of the same bacteria by direct culture in other studies.

CONCLUSIONS

We ascribe the increased sensitivity of the immunoassay in our study to: 1) a more standardized and vigorous sample dispersion that improves release of particulate and soluble antigens from dental plaque biofilm, and 2) better visualization of the reaction product of the enzyme-linked immunoassay. High-technology assays, such as diagnostic immunoassays, have a significant potential for future development in dental diagnosis, because they simplify detection and measurement of biologically important markers such as specific bacteria in clinical samples. Commercial assays also have an important potential for standardization of clinical measurements of biological markers.

Identification of periodontal disease-associated bacteria in the "plaque-free zone"

BACKGROUND

Subgingival plaque bacteria live within a biofilm covered with glycocalyx, and little is known of the bacterial species associated with biofilm formation at the bottom of human periodontal pockets, the so-called "plaque-free zone"(PFZ).

METHODS

Seventy-seven extracted teeth from 56 patients with severe advanced adult periodontitis were examined. Porphyromonas gingivalis, Campylobacter rectus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Treponema denticola, Prevotella nigrescens, and Actinomyces viscosus were examined by scanning immunoelectron microscopic techniques, using both secondary and back-scattered imaging, with rabbit antibodies specific for each bacteria.

RESULTS

Secondary electron images showed that rods, filaments, and spirochete-shaped bacteria formed small aggregates in the PFZ. Some of the bacteria were covered with an amorphous film-like structure. By back-scattered electron imaging, positive reactions with anti-P. gingivalis were found in 8 of 13 samples examined, and film-like structures coated several cells of 6 positive samples examined. Labeled cells with anti-C. rectus, anti-T. denticola and anti-P. nigrescens were detected in 3 of 11, 5 of 10, and 1 of 8 samples examined. A. viscosus were found in 6 of 11 of the samples. A. viscosus tended to overlay the amorphous capsula and aggregate. F. nucleatum and A. actinomycetemcomitans were not detected in any samples examined.

CONCLUSIONS

These findings indicated that P. gingivalis, C. rectus, T. denticola, P. nigrescens, and A. viscosus were present in the PFZ, and that some specified bacteria were possibly related to plaque-biofilm formation of subgingival plaque.