Evaluation of oral health related to body mass index.

OBJECTIVE: Poor oral health has previously been related to high body mass index (BMI). We aimed at exploring the link between BMI and several oral health markers, after adjustment for dietary patterns and plasma insulin, both of which could act as mediators. SUBJECTS AND METHODS: Dental examination was performed in a sample of 186 French subjects aged 35-64 years and selected from the general population to assess number of missing teeth, periodontitis, clinical attachment loss (CAL), probing pocket depth (PD), gingival index (GI) and plaque index (PI). Data collection also included a food-frequency questionnaire. BMI (considered as outcome variable) was categorized into quartiles, and as BMI<25; 25 ≤BMI<30; and BMI ≥ 30 kg m(-2) . RESULTS: After adjustment for age, gender, education level, smoking, physical activity, energy intake and C-reactive protein, BMI was statistically associated with missing teeth, PD and PI, but not with CAL, GI or periodontitis. After additional adjustment for 'high-carbohydrate' diet and plasma insulin or HOMA (homeostasis model assessment) index for insulin resistance, the statistical relationship between BMI and oral variables remained significant only for PD and PI. CONCLUSIONS: Plaque index, reflecting dental plaque, and PD, closely linked with periodontal inflammation and infection, are statistically associated with high BMI and obesity, independently of dietary patterns and insulin resistance.

Amoxicillin prophylaxis in oral surgery.

INTRODUCTION: Postoperative infection is the most common postsurgical oral complication but no double-blind, randomized, placebo-controlled trial has been made yet to assess amoxicillin prophylaxis for oral surgery. The aim of this pilot study was to assess the effectiveness of prophylactic amoxicillin 3g per os versus placebo in the prevention of postoperative oral infections. METHODS AND MATERIALS: A 5-year, multicentric, randomized, double-blind clinical trial was made on healthy patients undergoing complex oral surgery. Final analysis was by intention to treat. RESULTS: The 286 patients were randomly assigned to the amoxicillin or placebo group. After a mean follow-up of two weeks, 11 patients in the control group and three patients in the amoxicillin prophylaxis group developed a postoperative infection (P=0.001 in unilateral test). The hazard ratio was 0.27 [95% CI: 0.07-0.94]. CONCLUSION: Amoxicillin prophylaxis seems to be effective in preventing postoperative infection in complex oral surgery, especially when mandibular third molars and multiple avulsions are involved.

[Prevalence of Helicobacter pylori detected by real-time PCR in the subgingival plaque of patients with chronic periodontitis]. / Prévalence d'helicobacter pylori détecté par PCR en temps réel dans la plaque sous-gingivale des patients atteints de parodontite chronique.

BACKGROUND: Helicobacter pylori plays a significant role in gastric disease. The aim of the present pilot study was to evaluate the prevalence of H. pylori detected by real-time polymerase chain reaction (real-time PCR) in the sub-gingival plaque of chronic periodontitis patients and to determine periodontopathogens profile of positive sites at H. pylori. METHODOLOGY: 109 subgingival samples collected from 17 subjects with chronic periodontitis were studied. The DNA was extracted from the oral samples and analyzed for the presence of H. pylori by real-time PCR (LightCycler) using 16S rRNA#120 primers which targeted the 16S rRNA gene. DNA from H. pylori DSM 4867 was used as a positive control. Seven bacteria implicated in chronic periodontitis were selected to explore the presence of these periodontopathic species in the oral positive sites for H. pylori. RESULTS: 16 of 109 samples (14.7%) were positives of H. pylori. All the positives sites were also positives to Fusobacterium nucleatum and Eikenella corrodens, 62.5% to Porphyromonas gingivalis, 31.25% to Treponema denticola, 25% to Prevotella intermedia, 12.5% to Aggregatibacter actinomycetemcomitans and 6.25% to Tannerella forsythia. CONCLUSIONS: H. pylori may be present in the subgingival plaque samples of patients with chronic periodontitis who are resident in a developing country. F. nucleatum and E. corrodens could coaggregate with H. pylori in the subgingival dental plaque.

Interest in a new test for caries risk in adolescents undergoing orthodontic treatment.

It has been reported that patients undergoing orthodontic treatment present a high risk of caries. Recently, an immediate chair-side test was proposed, displaying the intra-oral lactic acid production of cariogenic bacteria. The aim of this 12-month follow-up prospective cohort study was to evaluate the association between having a high score on this test and caries occurrence in 110 young patients scheduled for orthodontic treatment. Caries occurrence was studied by Kaplan-Meier curves and Multivariate Cox models allowed the examination of its association with covariates. Fifty four patients developed at least one carious lesion during the follow-up period. At baseline, approximately 70% of the patients presented a high risk of caries according to the test and this number came close to 80% by the study's completion. According to the Kaplan-Meier estimator, 51% (CI(95%) 0.40, 0.60) of the sample would have developed at least one carious lesion during the follow-up. The test score was then associated with age, DMFT, and caries occurrence. This study showed that a high test score at baseline associated with a high DMFT predicted a high risk of caries (RR = 2.6). Taking the patient's age into consideration, an increase of 1 year resulted in a 10% decrease of the risk of caries occurrence (RR = 0.89). Within the limits of this longitudinal study, it may be concluded that this test is useful to evaluate the risk for dental caries in adolescents with orthodontic treatment. Furthermore, the distribution of the lesions in our sample suggests specific clinical approaches for this group of patients.

Efficacy of periodontal treatment on glycaemic control in diabetic patients: A meta-analysis of interventional studies.

AIM: There is growing evidence that periodontal disease may favour the incidence or aggravation of diabetes and its complications. To investigate the issue, we conducted a meta-analysis of the effect of periodontal therapy on glycaemic control in diabetic patients. METHODS: A literature search was carried out using seven databases (Medline, EMBASE, LILACS, The Cochrane Library, Pascal, IADR Abstracts and Current Contents), with no language restrictions. We followed the QUOROM-recommended standards for improving the quality of reporting meta-analyses of interventional studies. RESULTS: Twenty-five studies, involving 976 subjects altogether, were included in the present systematic review. Of these, nine studies, involving a total of 485 patients, were controlled trials and were included in the meta-analysis. The standardized mean difference in HbA(1c) with the treatment of periodontal disease was 0.46 (95% CI: 0.11, 0.82). These findings suggest that periodontal treatment could lead to a significant 0.79% (95% CI: 0.19, 1.40) reduction in HbA(1c) level. CONCLUSION: The present meta-analysis represents the best information available to date that addresses this issue, and suggests that periodontal treatment could improve glycaemic control. Nevertheless, these results need to be viewed with caution because of a lack of robustness, and deficiencies in the design of some of the studies included. A randomized controlled trial with sufficient statistical power would help to confirm the results of this meta-analysis.

[The place of chemical products in oral hygiene for the prevention and treatment of periodontal disease]. / Place des produits chimiques d'hygiene bucco-dentaire dans la prevention et dans le traitement des maladies parodontales.

The mechanical elimination of the bacteria plaque is the basis of the prevention and the treatment of gingivitis and periodontitis. Chemicals products used in the control of supra and subgingival plaque show a great importance because of individual and professional difficulties which constitute an impediment to the effective elimination of the bacteria plaque. However, by this time, there's no miracle product for oral hygiene capable at long term to take over from the tooth-brush and paste. The use at long term of chemicals in the bacteria plaque control can't be recommended because of their following effects and their slight effectivity-cost ratio. Nevertheless, oral hygiene chemicals combined with mechanical treatment provide very good results. Particularly, when used in the form of subgingival irrigation or slow liberation materials set in the periodontal pocket.

[In vitro study of chlorhexidine resistance in subgingival bacteria]. / Etude in vitro de la résistance à la chlorhexidine des bactéries de la flore sous-gingivale.

Chlorhexidine is an antibacterial agent of the bisguanide family. It's the most effectual molecule of all antiseptics for oral use. Because of its so frequent use, we have elaborated a protocol in order to estimate the resistance of the sub-gingival flora bacteria to its actions. We have determined the minimal inhibitory concentration of the different observed bacteria species and, have from that stage, progressively increased the concentration at a rate of 5 micrograms/ml. The obtained results show that the bacteria can undergo structural and/or biochemical alterations to adapt to more significant concentrations.

[A comparative study of various evaluation methods of the antibiotic sensitivity of strict anaerobic bacteria of the subgingival flora]. / Etude comparative de différentes méthodes d'evaluation de la sensibilité aux antibiotiques des bacteries anaérobies strictes de la flore sous-gingivale.

The study on the sensitiveness of slow-growing anaerobes bacteria to antibiotics is delicate when you consider the technical motives that make it difficult to transpose the standard methods frequently used in microbiological laboratories. The three main methods used to determine susceptibility to antibiotics are: disk-diffusion test, antibiotics containing microdilution plates and ATB ANA (bioMérieux). The aim of this study is to compare the effectiveness of each of these methods on severe anaerobes bacteria isolated in sub-gingival flora of patients suffering from developing periodontitis (rapidly progressive periodontitis, refractory periodontitis, active stage of adult chronic periodontitis). The observed bacteria are: Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus micros. Antibiotics used are: ampicilline, amoxicilline, tetracycline, erythromycine, metronidazole. The comparison of the minimal inhibitory concentrations (M.I.C) of each of these methods has permitted to show a strict correlation in the results observed with these three methods, if only the growth of the severe anaerobes bacteria on agar medium does not exceed 72 hours.

[An in vitro study of the action of kola nitida on bacterial strains implicated in dental caries and periodontal diseases]. / Etude in vitro de l'action de la kola "nitida" sur les souches bactériennes impliquées dans les caries dentaires et les maladies parodontales.

The Nitida Kola is a substance extracted from the kolanut. In West Africa its use by chewing is widespread among the Manding people. It's said to have tonic, stimulant and aphrodisiac characteristics and even recent studies have shown that it has antibacterial characteristics. The aim of this study is to make an estimation of the Nitida Kola's effects on different bacterial species involved in the two main oral and dental pathologies (teeth decays and periodontal illnesses). The obtained results indicate that the kola extract is not effectual against the tried-out bacteria at regular dose used by chewing.

Effect of voxel size on the accuracy of 3D reconstructions with cone beam CT.

OBJECTIVES: The various types of cone beam CT (CBCT) differ in several technical characteristics, notably their spatial resolution, which is defined by the acquisition voxel size. However, data are still lacking on the effects of voxel size on the metric accuracy of three-dimensional (3D) reconstructions. This study was designed to assess the effect of isotropic voxel size on the 3D reconstruction accuracy and reproducibility of CBCT data. METHODS: The study sample comprised 70 teeth (from the Institut d'Anatomie Normale, Strasbourg, France). The teeth were scanned with a KODAK 9500 3D® CBCT (Carestream Health, Inc., Marne-la-Vallée, France), which has two voxel sizes: 200 µm (CBCT 200 µm group) and 300 µm (CBCT 300 µm group). These teeth had also been scanned with the KODAK 9000 3D® CBCT (Carestream Health, Inc.) (CBCT 76 µm group) and the SCANCO Medical micro-CT XtremeCT (SCANCO Medical, Brüttisellen, Switzerland) (micro-CT 41 µm group) considered as references. After semi-automatic segmentation with AMIRA® software (Visualization Sciences Group, Burlington, MA), tooth volumetric measurements were obtained. RESULTS: The Bland-Altman method showed no difference in tooth volumes despite a slight underestimation for the CBCT 200 µm and 300 µm groups compared with the two reference groups. The underestimation was statistically significant for the volumetric measurements of the CBCT 300 µm group relative to the two reference groups (Passing-Bablok method). CONCLUSIONS: CBCT is not only a tool that helps in diagnosis and detection but it has the complementary advantage of being a measuring instrument, the accuracy of which appears connected to the size of the voxels. Future applications of such measurements with CBCT are discussed.

[Impact of periodontal disease on arterial pressure in diabetic mice]. / Impact de la maladie parodontale sur la pression artérielle des souris diabétiques.

Diabetes-driven cardiovascular diseases represent a high challenge for developed countries. Periodontal disease is strictly linked to the aforementioned diseases, due to its Gram negative-driven inflammation. Thus, we investigated the effects of periodontal disease on arterial pressure during the development of diabetes in mice. To this aim, C57BL/6 female mice were colonized with pathogens of periodontal tissue (Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum) for 1month, whereas another group of mice did not undergo the colonization. Subsequently, all mice were fed a high-fat carbohydrate-free diet for 3months. Then, arterial pressure was measured in vivo and a tomodensitometric analysis of mandibles was realized as well. Our results show increased mandibular bone-loss induced by colonization with periopathogens. In addition, periodontal infection augmented glucose-intolerance and systolic and diastolic arterial pressure, parameters already known to be affected by a fat-diet. In conclusion, we show here that periodontal disease amplifies metabolic troubles and deregulates arterial pressure, emerging as a new axis of metabolic investigation.

Cone-Beam Computed Tomography: a useful tool for dental age estimation?

Assessment of oral hard tissues can be of great help in determining the age of an individual. The development and physiological aging of teeth provide many clues for estimating age, in methods that are mainly based on conventional radiography. Although these conventional techniques reveal information on the anatomical and pathological characteristics, they only show two-dimensional images of a system that originally exists in three dimensions. With the growth and development of three-dimensional imaging, it has become possible to include measurements such as volumetric data, which give a better grasp of the continuous process of tooth mineralization. Up to now, these measurements have been obtained in vitro using micro-computed tomography (micro-CT) but three-dimensional imaging has recently been enriched by a new technique: Cone-Beam Computed Tomography (CBCT), which is devoted to the maxillo-facial sphere. These acquisitions may offer real potential for exploiting and analyzing volumetric measurements of teeth. We hypothesize that, using CBCT acquisitions, multiple regression analysis including quantitative volumetric measurement of various parts of each tooth can be useful to determine significant variables for dental age estimation in living subjects. Currently, CBCT examinations are being performed and contain important information for the quantitative study of dental tissue. Although CBCT examinations are conducted in the first intention of making a clinical diagnosis or prognostic evaluation, they could be used as an initial database for the measurement of dental volumes and their ratios, thus furnishing preliminary evaluations and information. Multiple regression analysis requires the constitution of a larger sample sizes which may demonstrate that CBCT data can be helpful to study other aspects of dental morphology in greater depth, especially dental growth. In this hypothesis, integration with a larger network system would be necessary. CBCT data could be helpful in defining new parameters for the rating of dental development, for a quantitative description of the fractions of crown and root and could offer new research oriented towards various aspects of teeth and jaws, thanks to its broad sampling possibilities.

Accuracy of 3D reconstructions based on cone beam computed tomography.

Three-dimensional imaging of teeth will increase its impact in clinical practice if reconstructions are metrically accurate. We hypothesized that, with cone beam computed tomography (CBCT) data, three-dimensional images of teeth can be reconstructed with the same accuracy and precision as with in vitro micro-computed tomography (micro-CT) data acquisition, the current reference standard. We used a sample of CBCT and micro-CT data taken of tooth germs. Volumes obtained with CBCT and micro-CT devices were statistically similar (n = 120, Passing-Bablok regression). Geometric deviations between CBCT and micro-CT three-dimensional surface reconstructions did not show any areas of important and systematic errors. Future investigations with the use of larger samples may also demonstrate that CBCT data will be helpful for a more in-depth study of other aspects of dental morphology--for example, assessing tooth development. With sufficient accuracy for clinical situations, potential future medical applications of such measurements with CBCT are envisaged.

[Comparison of four different primer sets for detection of Helicobacter pylori in gastric biopsies and oral samples by using real-time PCR]. / Comparaison de quatre paires d'amorces différentes dans la détection d'Helicobacter pylori dans les biopsies gastriques et les prélèvements oraux.

AIMS: The presence of Helicobacter pylori. in the oral cavity remains controversial and the most appropriate method for detection of oral H. pylori has yet to be established. The aim of the present study was to compare four different primer sets on the detection of H. pylori in gastric biopsies and oral samples using real-time PCR. MATERIAL AND METHODS: Gastric biopsy and oral samples were collected from eight patients with gastric symptoms. DNA from clinical samples was extracted and analyzed for the presence of H. pylori by real-time PCR (LightCycler 2.0) using four pairs of primers which targeted 16S rRNA (16S rRNA#295; 16S rRNA#120) or glmM (glmM#294; glmM#722) DNA genes. Three H. pylori strains and three clinical isolates served as reference. The specificities of the four primer pairs were examined for seven oral microorganisms and two Helicobacter non-pylori species. RESULTS: Primer pair 16S rRNA#120 showed an acceptable specificity and a high sensitivity. Primer pairs glmM#294 and glmM#722 demonstrated a high specificity but a low sensitivity and primer pair 16S rRNA#295 demonstrated a poor specificity but acceptable sensitivity. Four H. pylori positive gastric biopsies were demonstrated by culture, histology and real-time PCR with primer pairs 16S rRNA#295 or 16S rRNA#120. No H. pylori was detected in oral samples, either by culture or by real-time PCR. CONCLUSION: Of the four different primer pairs examined, 16S rRNA#120 was the most appropriate to detect H. pylori in clinical samples using real-time PCR.

Absence of Helicobacter pylori in the oral cavity of 10 non-dyspeptic subjects demonstrated by real-time polymerase chain reaction.

Helicobacter pylori plays a significant role in gastric disease. However, the presence of this bacterium in the oral cavity remains controversial. The aim of the present study was to detect and quantify H. pylori in 29 different sites of the oral cavity in non-dyspeptic subjects by means of real-time polymerase chain reactions (PCR). Ten subjects without gastric symptoms were studied. Samples from unstimulated saliva, three sites of the tongue, oral mucosa, and 12 sites of both supragingival and subgingival plaque were collected from each subject. DNA was extracted from the oral samples and analysed for the presence of H. pylori by real-time PCR (LightCycler) using JW23/22 primers which targeted the 16S rRNA gene. DNA from H. pylori DSM 4867 was used as a positive control. Amplification efficiency for the LightCycler 2.0 runs ranged from 1.8 to 2.4. Melting curve analysis identified all the positive control capillaries, which contained H. pylori reference DNA, as a single and narrow peak at a melting temperature between 84.5 and 84.9 degrees C. All the negative control capillaries with no template control and the 29 oral samples from each subject showed either no melting peaks or broad melting peaks below 80 degrees C, which were considered as primer dimers. Therefore, H. pylori was not detected from any of the 290 oral samples. As a conclusion, H. pylori seems not to be permanently present in the oral cavity of a non-dyspeptic population.

Carpegen real-time polymerase chain reaction vs. anaerobic culture for periodontal pathogen identification.

BACKGROUND/AIMS: The aim of this study was to compare two methods of microbiological diagnosis, anaerobic bacterial culture and real-time polymerase chain reaction (PCR), for the detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Treponema denticola. METHODS: Seventy-two samples were collected from 18 patients who were suffering from aggressive periodontitis. The data obtained were compared for the two methods. RESULTS: The results obtained with real-time PCR were different from those obtained with bacterial culture. The detection differences were 3% for A. actinomycetemcomitans, 8.33% for P. intermedia, and 12.5% for F. nucleatum. However, the differences for P. gingivalis and T. forsythia were 51.39% and 36.11%, respectively. No comparison was possible for T. denticola because it cannot be identified in culture. The variations found were the result of the better detection level (10(2) pathogens) of the PCR probe. Unlike bacterial culture, PCR allows the detection of T. denticola, which does not forming colonies and is oxygen sensitive. For F. nucleatum, T. forsythia and P. gingivalis, the real-time PCR technique was more sensitive than culture. CONCLUSION: Good results were obtained with the real-time PCR technique for the six periopathogens targeted. This method seems to be indicated for its simplicity, rapidity and reproducibility but it cannot analyze data for an antibiotic susceptibility test. The periodontist must therefore choose one of these two methods according to his specific clinical objective: to obtain rapid, specific detection even with weak initial concentrations (but for targeted periopathogens only) or to be non-specific and analyze the pathological activity with an antibiogram.

[Bacterial DNA alteration by plasma generated atomic nitrogen. Real-time PCR detection contribution]. / Dégradation de l'ADN bactérien par de l'azote atomique produit par plasma. Apport de la détection par PCR en temps réel.

AIMS: Bacterial sterilization by the technology of plasma in post-discharge shows a growing interest. The main appeal of this new process resides in its action at dry and low temperature (60 degrees C). This technology would be therefore useful for the complex medical equipment, sensitive to the oxidization, humidity and/or requiring a temperature lower than 60 degrees C. The objective of this survey is to demonstrate the activity of an atomic flux emanating a plasma of pure molecular nitrogen on the bacterial DNA: does the plasma of nitrogen damage the genetic material? MATERIALS AND METHODS: The bacteria tested (Bacillus stearothermophilus, Staphylococcus aureus MRSA and Helicobacter pylori) are cultivated on suitable agar, and the bacterial DNA is extracted from every CFU by the technique of the columns (High Pure PCR Template, Roche). Every quantity of DNA extracted is diluted in 1 ml pure water. Then, 50 microl of each of these solutions of DNA are laid down in sterile Nunclon's plates holes, which undergo an advanced emptiness cycle during 60 minutes. The DNA residues will be then introduced during 40 minutes in a plasma sterilization surrounding wall (Plasmalyse), Satelec) where the debit of nitrogen, the pressure and the temperature are adjusted respectively to 1 L x min(-1), 5 Torrs and 60 degrees C. The DNA so ''plasmalysé'', is recovered then by aspiration in 500 mul pure water and processed to undergo an amplification/detection by Real-Time PCR (LightCycler2.0, Roche). The DNA ''plasmalysé'' will be compared to the intact DNA control(1), to the DNA control control(2) having undergone the cycle of emptiness solely, as well as to the DNA control(3) solely heated to 60 degrees C during 40 min. RESULTS: The amplification curves demonstrated that the only advanced emptiness and the only heat don't have any activity on the bacterial DNA. On the other hand, the DNA ''plasmalysé'' shows a deterioration of the amplified sequences. CONCLUSION: The genomic bacterial DNA, once extracted, is damaged by the gaseous flux of nitrogen plasma. A new sterilization process of the medical material will presumably impose itself in medium-term.

[Efficacy variation of erythromycin and spiramycin on periopathogens in aggressive periodontitis. An in vitro comparative study]. / Variabilité de l'efficacité de l'érythromycine et de la spiramycine sur les pathogènes parodontaux dans les parodontites agressives. Etude in vitro comparative.

AIMS: Erythromycin (ERY) and spiramycin (SPI) are the most frequently prescribed macrolides by dentists. However, the emergence of resistant anaerobic subgingival bacteria imposes an increased vigilance. This study aims to compare these macrolides efficacy on principal periopathogens. MATERIALS AND METHODS: Twenty adult patients with aggressive periodontitis were selected and a total of 60 samples were taken from subgingival flora. Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Peptostreptococcus micros and Actinobacillus actinomycetemcomitans were isolated according to J. Slots's rapid identification method. The susceptibilities to ERY and SPI were studied using disk diffusion susceptibility test and minimum inhibitory concentration test (MIC test). RESULTS: The efficiency variability of ERY and SPI on the 50 isolated anaerobic periopathogens was present either interindividually (between different patients) and intra-individually (within the same patient). While 68% of the tested anaerobic bacteria were sensitive to SPI (22% resistant), only 54% were sensitive to ERY (34% resistant). Although moderate, the efficacy of SPI seemed more regular in general than ERY: it's variation coefficient (40%) is lower than the ERY one (53%). The 7 A. actinomycetemcomitans tested showed all a high resistance. CONCLUSION: In a general way, the spectre of activity of SPI is stacked in that of ERY. However, this study shows a better and regular activity of SPI on the main tested periopathogens. These results are in favour of the use of SPI in periodontology when penicillins and doxycycline are not useful because specific problems are identified (allergy, pregnancy...).

Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study.

BACKGROUND/AIMS: The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient). MATERIAL AND METHODS: A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2-4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby-Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test. RESULTS: Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros. CONCLUSIONS: The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.