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.

Improved oral hygiene and Candida species colonization level in geriatric patients.

OBJECTIVES: This work consists in improving oral hygiene (OH) for elderly dependent people in long-term hospital care, in order to decrease the degree of colonization and the associated risk of developing oral candidiasis. As this population frequently suffers from such colonization and because it is difficult to install and practice OH care, a study protocol was designed at the request of geriatricians. The objective of the present study was to set up a programme of OH, applied by the care staff, and to monitor oral colonization of by Candida spp. BASIC RESEARCH DESIGN: We compared the levels of hygiene and Candida spp. colonization for a group of 110 long-term patients in geriatric departments at T1, when clinical data were collected and oral mycological samples taken before the OH protocol was applied, and at T2, during the postprotocol phase after 3 months of application, when the clinical data and sample collection were repeated. RESULTS: During these 3 months 11 patients died. These patients were excluded from the results, which are presented for matched series of the 99 patients still present at T2. Statistical analysis comparing the clinical and biological parameters at T1 and T2 established that there had been an improvement in OH: the 'adequate' level was reached for 72.4% of patients at T2 compared with 41.8% at T1 (P < 0.001) and the 'very inadequate' level was observed for 9.2% at T2 compared with 27.9% at T1 (P < 0.01). A reduction was observed in the number of patients showing the highest degree of C. albicans and C. glabrata colonization (> 50 colony forming units) from 41.9% at T1 to 24.9% at T2 (P < 0.05) and from 56.4% at T1 to 13.0% at T2 (P < 0.05) respectively. The number of patients with candidiasis fell significantly from 43.2% at T1 to 10.2% at T2. CONCLUSIONS: The OH protocol led to an overall decrease in Candida spp. colonization, a significant reduction in the number of candidiasis and an improvement in the level of oral and denture hygiene but vigilance is still necessary concerning OH care and the initial training of staff in specific care of the mouth.

[Caries free smile: a dental health educational programme]. / "Souris sans carie": une campagne d'éducation bucco-dentaire pluridisciplinaire.

UNLABELLED: A multidisciplinary team associating members from the hospital, national education and local council sectors prepared, and led, a carie-free smile educational campaign in Toulouse. OBJECTIVES: The aim was two-fold: to teach children how to manage their routine oral hygiene while giving a positive image to health care-hence the carie-free smile theme chosen by the team; secondly, to promote an awareness campaign targeting professionals in the education sector (public health sector, independent paediatricians and odontologists) who together constitute the transmitters of our initiative. MATERIAL AND METHODS: The action involved 12,000 children in the 5-8-year age group from 76 public and private schools, 36 kindergarten and primary school leisure centres, six holiday centres together with infant patients from the children's hospital, all of whom were volunteers in the scheme. The team produced back-up material in the form of posters, booklets and stickers; there was also a website dealing with oral hygiene themes, caries and their treatment. Those taking part included practising dentists and students of dentistry. Before the presentation, posters were sent to teachers and other educational partners so as to prepare the children; this included an interactive phase in the presence of the teacher, and a brushing session. Each child was given a booklet, a sticker and a toothbrush. RESULTS: By means of a poll organised among the partners the impact of the campaign could be assessed: firstly, on teachers and children by evaluating their motivation in the setting up of the toothbrushing session in 17 classes following the midday meal, thus appraising their appreciation of the visual material, and secondly, to the dentistry students: the future dentists had noted disparities in oral hygiene practices according to residential area, and thus could appreciate the importance of early provision in the school curriculum, as well as the value of accomplishing this health education task in the daily exercise of their profession.

Metronidazole susceptibility testing of anaerobic bacteria associated with periodontal disease.

The aim of the present investigation was to determine the susceptibility of Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium and Peptostreptococcus micros to metronidazole in vitro. Two methods were applied on each isolated strain: agar dilution and epsilometer Etest. A total of fifty three wild test strains (13 P.intermedia, 14 P. gingivalis, 14 F.spp and 12 P.micros) were isolated from patients with periodontitis. The Etest appears to be a simple, rapid and reliable method for the metronidazole susceptibility testing. The results show that all P.intermedia, P.gingivalis and F.spp strains were susceptible to metronidazole. The mean values of minimal inhibitory concentration obtained with the agar dilution method were, respectively, 0.98 microg/ml, 0.122 microg/ml and 0.242 microg/ml. For P.micros, the minimal inhibitory concentration was of 12.14 microg/ml. Comparatively to break points, only 60% of P.micros strains seem to be susceptible, in vitro, to metronidazole. This study demonstrated the excellent activity of metronidazole against P.intermedia, P.gingivalis, F.spp except perhaps for P.micros.

Salivary defence factor concentrations in relation to oral and general parameters in HIV positive patients.

The objective of this study was to determine the relationships between saliva protein concentrations, oral mucosal lesions, and systemic parameters in HIV positive patients and controls. Twenty-three control volunteers and 58 HIV-antibody positive patients received a complete oral examination and medical evaluation. In saliva and serum samples, protein concentrations were recorded by a nephelometric method. The systemic parameters assessed were CD4+ cell count, CDC stages and antiretroviral therapy. Oral mucosal lesion prevalence was higher among subjects with lower CD4+ counts. Considering the protein profile, correlations were recorded between saliva and serum protein concentration for IgA, haptoglobin and alpha1-proteinase inhibitor. Using assays of immune and non-immune saliva defence factors, we found that the evolution of cellular immuno-suppression during HIV infection was correlated to oral mucosal disease, showing a relationship between local and general systems.

In vitro study of the penetration of three bacterial strains into root dentine.

The purpose of this study was to assess in vitro migration of the following three bacterial species into dentinal tubules: Streptococcus sanguis, Actinomyces naeslundii and Prevotella intermedia. Twenty-seven bovine incisors were randomly divided into three groups. Only the root dentin was used for the experiment. Within each group, the nine incisors were sectioned into 36 dentin blocks that were incubated with one of the tested bacterial suspensions. Twelve samples were taken after 10, 20, and 28 days. Half the samples were observed with scanning electron microscopy and the others with light microscopy after standard histologic procedures, and the depth of bacterial penetration was measured. Analysis of the examinations showed that whatever the technique used, only one strain on this experimental model migrated into dentinal tubules. S. sanguis was observed at a depth of 792 microns, but no migration was observed for either A.naeslundii or P.intermedia. The differences in migration of the bacteria tested appear to be related to their morphologic factors and cellular arrangement.

[The adhesion of Actinobacillus actinomycetemcomitans to oral epithelial cells]. / Etude de l'adhesion d'Actinobacillus actinomycetemcomitans aux cellules epitheliales buccales.

Adherence is a major pathogenicity factor for many bacteria. The aim of this study was to measure the adherence potential of Actinobacillus actinomycetemcomitans (A.a.) for buccal epithelial cells (BEC). In the second part of the study, the inhibitory potential of saliva on adherence between A.a. and BEC was tested. Saliva specimens were obtained from three groups of subjects: a group of normal subjects (NS), a group of subject with localized juvenile periodontitis (LJPS) and a group of subjects with adult periodontitis (APS). Clinical strains of A.a. showed a major adherence potential for BEC (25.5 A.a./BEC). In contrast, reference strains of bacteria appeared to possess a much lower potential for adherence (12.6 A.a./BEC). Saliva samples taken from from the LJPS and APS group had a high inhibitory adherence potential, since in each of these groups a reduction of 60.9% and 66.7% respectively, was observed in the number of bacteria adhering to BEC.

[The distribution and prevalence of Haemophilus actinomycetemcomitans in the oral cavity]. / Distribution et prévalence de Haemophilus actinomycetemcomitans dans la cavité buccale.

The prevalence and distribution of Haemophilus actinomycetemcomitans (H.a.) were studied in 3292 specimens of subgingival plaque on the four subgingival aspects of all teeth of the dental arch, 150 specimens from the mucosal surface (tongue and cheek) and 30 saliva specimens in 30 subjects. The sample population of 30 subjects was subdivided into three groups: 10 normal subjects, 10 subjects with localised juvenile periodontitis (SLJP) and 10 subjects with adult chronic periodontitis (SACP). The prevalences of H.a. in subgingival areas of each group mentioned were 30%, 90% and 60% respectively. Scores for prevalence obtained with other types of specimens proved to be lower except for saliva specimens which appear to be a less representative marker of subgingival prevalence of H.a.. Histograms for the distribution of H.a. revealed a predominance of this microorganism on the proximal surface of molar teeth in the three groups of patients. Only the SLJP also exhibited a high prevalence on the proximal aspect of the incisor teeth. The wide distribution of H.a. in all of the clinical groups studied suggests that this bacterium is not a good marker of periodontal disease and that it is necessary to define the most characteristic phenotypes and genotypes.

[The transmission of Actinobacillus actinomycetemcomitans between spouses]. / Etude de la transmission d'Actinobacillus actinomycetemcomitans entre conjoints.

The aim of this investigation was to study the transmission of Actinobacillus actinomycetemcomitans (A.a) between husband and wife when one of them was affected by acute juvenile periodontitis (P.A.J.). The hypothesis tested was the role played by the reservoir of the non-infected partner in explaining the frequent recurrences of the disease in the affected spouse despite combined antibiotherapeutical and surgical treatments. Twenty subjects with P.A.J. were studied. A.a. was found in the sub-gingival flora of nineteen of them. This micro-organism was also isolated in each of the partners of the nineteen patients. Each couple presented strains of the same biotype. The serotypes were studied in seven of these couples and confirmed the results of the biotypes. All theses results are in favour of the transmission of A.a. between partners.

[Mastication and the electromyographic silent period in denture wearers]. / Mastication et période de silence électromyographique chez des porteurs de prothèses.

The purpose of this study is to compare the masticatory efficiency and the physiological activity of masticatory muscles among patients with removable partial dentures (R.P.D.) and patients with natural dentition. The masticatory efficiency is assessed from the duration of chewing sequences for various foods, from the first masticatory cycle to the swallowing. The physiological activity is tested by the duration of the inhibition reflex called the "silent period" (S.P.) obtained upon each muscle examined: 29 subjects are examined, 24 of them had a R.P.D.; they were divided into four groups according to the extent of their edentation; 5 control subjects have full natural dentition. The study is performed using global electromyography of the two masseter muscles and the two anterior temporal muscles. The mastication of the control subjects appears to have a regular alternance of working potential and periods of rest. The duration of the chewing sequences is determined by the nature of the food, brief for soft food, long for hard food. The mastication of patients with R.P.D. appears more irregular with a lengthening of active phases. The duration of chewing sequences is significantly longer for the control subjects. The duration of the S.P. is 19-21 milliseconds for the masseter muscles of the patients with dentures and the control patients, and 20-22 milliseconds for the temporal muscles for the same individuals. The differences of the S.P. durations between control subjects and patients with R.P.D. is never significant.(ABSTRACT TRUNCATED AT 250 WORDS)

[A comparison between 4 subgingival bacteriologic sampling technics]. / Comparaison entre quatre techniques de prèlévements bacteriologiques sous-gingivaux.

A comparative study of four classical techniques employed in the sampling of subgingival microflora (paper points, swabbing, curette and washing followed by aspiration) has been carried out. This study was based upon quantitative criteria (number of bacteria sampled) and qualitative criteria (number of morphologically distinct colonies found per sampling technique). Sampling was done on three different groups of patients: a control group, a group of patients with gingivitis and a group of patients with periodontitis. The curette sampling technique was found to be efficient both quantitatively and qualitatively. Difficulties in standardizing this method however were encountered with the failure to achieve reproducible results. For this reason the technique of paper point was preferred. This method was found to be more reliable and reproducible in each of the three groups of patients sampled.

[A procedure for the 3-dimensional recording of human mandibular movements]. / Un procédé d'enregistrement tri-dimensionnel des mouvements de la mandibule chez l'homme.

A 3 dimensional process of recording the human mandible movements. Our system belongs to a general process made by the C.N.E.S. (Centre National d'Etudes Spatiales) in Toulouse; it records and measures the movements of body and limbs of spacemen. A test of this process is adapted for movements of mandible. The system uses a various instrumentation: two electronic cameras; infrared rays; reflectors; a multiplexor case; a magnetoscope; a dimultiplexor; a computer; two screens of control. Four reflectors are fixed on the face of subject; two others are fixed on a metallic system that is glued on the buccal face of inferior canines. These reflectors record the specific movements of mandible. Usual mastication and mastication on one side in turn are recorded in a young man with his natural teeth. Some graphs are showed for example. A data processing system measures the trajectory of mandible in the three dimensions of space, according to time and rapidity of movement. This video data processing seems to be a good method to analyze movements of mandible and mastication.

Presentation and physical evaluation of RadioVisioGraphy.

A comparison of physical properties has been made between conventional intraoral films and images made with the RadioVisioGraphy (RVG) system, a unit based on the charged coupled device. The RVG system uses considerably reduced levels of radiation to produce an image immediately after exposure. RVG resolution is slightly lower than that with silver halide emulsion films; however, radiographic information may be increased by electronic image treatment.

The silent period duration of the masticatory muscles.

This study was conducted to determine whether the reflex activity of the masticatory muscles is altered in prostheses wearers. The electromyographic silent period was measured on an oscilloscope screen. Thirty subjects were examined. Five subjects had natural dentitions. Twenty-five partially edentulous subjects wore removable prostheses. The silent period duration reached 18 to 21 ms on the masseter muscles and 20 to 22 ms on the temporal muscles. These values were not significantly different for subjects with and without teeth and in the control group. The duration of the silent period was the same for patients wearing prostheses and for subjects with natural teeth. This finding suggests that wearing a prosthesis does not change the normal activity of the masticatory muscles.

[Electromyographic study of mastication as a function of the denture in humans]. / Etude électromyographique de la mastication en fonction de la denture chez l'homme.

A study of mastication was conducted using global electromyography of the masseter and anterior temporal muscles. Thirty subjects were studied and distributed between two groups. A control group of 5 patients had a complete natural dentition. A group of 25 patients presented important bimaxillary tooth-loss and wore dentures. They performed masticatory cycles with and without their dentures. The masticatory efficiency of the edentulous patients was very low when compared to the control group. The use of the dentures moderately improved function. The durations of activity of the temporal muscles were slightly lengthened (but not significantly) in the edentulous patients and the denture wearers compared to control patients. The cyclic pattern of the mastication tracings persisted. On the contrary, the durations of activity of the masseters muscles were strikingly lengthened until total disappearance of the resting phases. The cyclic pattern of the mastication tracings in controls disappeared in edentulous patients and denture wearers. In the latter, the tracings were less irregular than in the edentulous patients. In conclusion, the electrical activity of temporal muscles were slightly affected by the absence and replacement of teeth, whereas the electrical activity of the masseter muscles was markedly altered.