Adjunctive antimicrobial chemotherapy based on hydrogen peroxide photolysis for non-surgical treatment of moderate to severe periodontitis: a randomized controlled trial.

Treatment of severe periodontitis with non-surgical therapy remains challenging in dentistry. The present study aimed to evaluate the clinical efficacy of hydrogen peroxide (H2O2) photolysis-based antimicrobial chemotherapy adjunctively performed with root debridement (RD) for moderate to severe periodontitis. A randomized controlled trial was conducted that included 53 patients with 142 test teeth. The test teeth were randomly assigned to one of three treatment groups: Group 1, RD + H2O2 photolysis; Group 2, RD followed by administration of a local drug delivery system (minocycline chloride gel); or Group 3, RD alone. Clinical and microbiological examination were performed for up to 12 weeks following treatment. Probing pocket depth (PPD) and bleeding on probing (BoP) were improved after each treatment session. At 12 weeks, Group 1 had achieved significantly lower PPDs than the other groups, though there were no significant differences in BoP between Group 1 and the other groups. Counts of Porphyromonas gingivalis, a known periodontal pathogen, in Group 1 were significantly lower than those in Group 3, and were comparable to those in Group 2. Therefore, it is suggested that H2O2 photolysis treatment can be used as a novel adjunctive antimicrobial chemotherapy for non-surgical periodontal treatment.

Pro-inflammatory cytokine responses in human gingival epithelial cells after stimulation with cell wall extract of Aggregatibacter actinomycetemcomitans subtypes.

Varying cytokine responses of human gingival epithelial cells (HGECs) by Aggregatibacter actinomycetemcomitans subtypes have been found. Most studies have used reference strains, whereas a few has evaluated the cytokine expression in response to clinical subtypes of this bacterial species. This study aimed to examine whether there was any difference in cytokine responses of HGECs stimulated with cell wall extract (CWE) from A. actinomycetemcomitans subtypes included clinical strains from Thai adult periodontitis, various serotypes and non-serotypeable strains, strains from deep or shallow pockets, and reference serotype strains. Totally 50 clinical strains and 7 reference strains of A. actinomycetemcomitans were analyzed for the expression of IL-1ß, IL-6, IL-8, and TNF-α mRNAs in HGECs by real time-PCR, and the IL-8 concentrations in cell-free supernatant measured using ELISA. An in vitro effect of released IL-8 on neutrophil migration was examined using transwell chambers. Result showed that among four cytokines studied, IL-8 mRNA was highly up-regulated by both clinical and reference strains. Serotype f revealed the highest expression compared to other serotypes. The JP2-like leukotoxin promoter gene and non-serotypeable (NS1 and NS2) demonstrated lower IL-8 responses compared to serotypeable strains, and IL-8 responses upon stimulation with clinical strains from deep pockets were also significantly lower than those isolated from shallow pockets (P < 0.01). Our findings suggest that the clinical isolates of A. actinomycetemcomitans associating with deep pockets, JP2-like leukotoxin promoter gene, NS1, and NS2 may interfere neutrophil function via minimal and immunosuppressing IL-8 responses, which may enhance their survival and virulence.

The subgingival periodontal microbiota of the aging mouth.

Different mechanisms have been hypothesized to explain the increase in prevalence and severity of periodontitis in older adults, including shifts in the periodontal microbiota. However, the actual impact of aging on the composition of subgingival biofilms remains unclear. In the present article, we provide an overview of the composition of the subgingival biofilm in older adults and the potential effects of age on the oral microbiome. In particular, this review covers the following topics: (i) the oral microbiota of an aging mouth; (ii) the effects of age and time on the human oral microbiome; (iii) the potential impact of inflammaging and immunosenescence in the host-oral microbiota interactions; and (iv) the relationship of the aging oral microbiota and Alzheimer's disease. Finally, we present analyses of data compiled from large clinical studies that evaluated the subgingival microbiota of periodontally healthy subjects and patients with periodontitis from a wide age spectrum (20-83 years of age).

Prevalence of Actinomyces spp. in patients with chronic periodontitis.

This study investigated the prevalence of Actinomyces spp. in shallow, deep and very deep pockets of patients with chronic periodontitis compared to healthy controls and correlated the results with clinical status. Twenty patients with chronic periodontitis and 15 healthy subjects were enrolled in this study. Clinical indices were recorded in a six-point measurement per tooth. From each patient samples of supra and subgingival plaque were taken separately from teeth with shallow, deep and very deep pockets. Samples of supragingival plaque and sulcular microflora were collected from the healthy subjects. All the samples were cultivated on different media at 37̊C in an anaerobic atmosphere for 7 days. All the suspect colonies were identified using a rapid ID 32 A system (bioMèrieux) and MALDI-TOF-MS analysis using an Autoflex II Instrument (Bruker Daltonics) together with in house developed identification software and a reference spectra database. A total of 977 strains were identified as Actinomyces. Actinomyces naeslundii/oris/johnsonii (430 isolates) was the most prevalent species and was found in all patients and in almost all of the healthy subjects. Significant differences (p=0.003) between the groups were found for Actinomyces odontolyticus/meyeri and Actinomyces israelii which were associated with periodontitis patients. Actinomyces dentalis was found in higher percentage (p=0.015) in the periodontitis group. Actinomyces gerencseriae and Actinomyces massiliensis were significantly more often found supragingivally than subgingivally (p=0.004, p=0.022, respectively) in the periodontitis group. Whether some Actinomyces species, definitely important plaque formers, are actively involved in the pathogenicity of chronic periodontitis needs further investigation.

[Fungal invasion of connective tissue in patients with gingival-periodontal disease]. / Invasión fúngica en tejido conectivo en pacientes con enfermedad gingivo-periodontal.

BACKGROUND: In the last few years unusual microorganisms have been isolated from subgingival biofilm, as possible initiators or contributors to periodontal disease, especially in patients who show no improvement during treatment. AIMS: To study the Candida invasion of the connective tissue in relation to subgingival biofilm presence. METHODS: A total of 55 immunocompetent patients of both sexes, between 21 and 55 years of age, non-smokers, without previous antimicrobial treatment, suffering periodontal diseases, were studied. Soft tissues, supragingival and subgingival plaque samples, and periodontal pocket biopsies were taken. Microscopic studies, cultures, assimilation profiles, and DNA amplifications were performed. RESULTS: In 35% of the samples, different species of Candida were isolated in cultures, especially Candida albicans. Hyphae invasions in the connective tissue were observed, in association with anaerobic microorganisms (Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans) in patients with periodontitis. CONCLUSIONS: Different species of Candida could be part of the periodontal plaque and could play an important role in the adherence to soft tissues, allowing deep invasion. They also could infect gingival pockets in patients with gingivitis, even in healthy locations, playing a commensal or opportunist role.

Analysis of gingival pocket microflora and biochemical blood parameters in dogs suffering from periodontal disease.

BACKGROUND/AIM: Periodontal diseases in dogs are caused by bacteria colonising the oral cavity. The presence of plaque comprising accumulations of aerobic and anaerobic bacteria leads to the development of periodontitis. Due to the fact that in a large percentage of cases periodontal diseases remain undiagnosed, and consequently untreated, they tend to acquire a chronic character, lead to bacteraemia and negatively impact the health of internal organs. The aim of the present study was to perform a qualitative microbiological analysis of gingival pockets and determine the correlations between selected morphological and biochemical blood parameters and the extent periodontal diseases. PATIENTS AND METHODS: Twenty-one dogs treated for periodontal diseases were qualified for the study and subsequently divided into two groups: with 3rd and 4th stage of periodontal disease. Swabs from the patients' gingival pockets were taken for bacteriological testing. Blood was tested for parameters including erythrocyte count, haemoglobin concentration, haematocrit values and leukocyte count. Blood serum was analyzed with respect to the concentrations of alanine transaminase (ALT), aspartate transaminase (AspAT/AST) and urea. RESULTS: The microbiological analysis of gingival pockets indicated the presence of numerous pathogens with a growth tendency in bacterial cultures observed in dogs with advanced-stage periodontal disease. The concentration of biochemical blood markers was significantly higher in dogs with 4th stage of periodontal disease, to compared to the 3rd-stage group. Morphological parameters were not significantly different with the exception of haemoglobin concentration, which was lower in dogs with 4th stage disease. In both groups, elevated leukocyte counts were observed. CONCLUSION: By conducting a detailed microbiological examination, it is possible to provide a better prognosis, plan adequate treatment and monitor dogs treated for peridontopathy.

Predominant bacterial species in subgingival plaque in dogs.

BACKGROUND AND OBJECTIVE: The dog has been used extensively for experimental and microbiological studies on periodontitis and peri-implantitis without detailed knowledge about the predominant flora of the subgingival plaque. This study was designed to evaluate the predominant cultivable bacterial species in dogs and compare them phenotypically and genotypically with corresponding human species. MATERIAL AND METHODS: Four subgingival samples were taken from two upper premolars in each of six Labrador retrievers. The samples from each dog were processed for anaerobic culture. From the samples of each dog, the five or six predominating bacteria based on colony morphology were selected and pure cultured. Each of the strains was characterized by Gram stain, anaerobic/aerobic growth and API-ZYM test. Eighteen strains showing clear-cut phenotypic differences were further classified based on DNA sequencing technology. Cross-reactions of DNA probes from human and dog strains were also tested against a panel of both human and dog bacterial species. RESULTS: Thirty-one strains in the dogs were isolated and characterized. They represented 21 different species, of which six belonged to the genus Porphyromonas. No species was found consistently in the predominant flora of all six dogs. Porphyromonas crevioricanis and Fusobacterium canifelinum were the two most prevalent species in predominant flora in dogs. DNA probes from human and dog species cross-reacted to some extent with related strains from humans and dogs; however, distinct exceptions were found. CONCLUSION: The predominant cultural subgingival flora in dogs shows great similarities with the subgingival bacteria from humans at the genus level, but distinct differences at the species level; however, a genetic relatedness could be disclosed for most strains investigated.

Microbiological analysis of gingivitis in pediatric patients under orthodontic treatment.

AIM: The aim of this study was to determine the relationship between gingival inflammation and changes in bacteria of the gingival sulcus in children in orthodontic treatment with brackets. STUDY DESIGN: this prospective study assessed gingival and plaque index of two groups: children with brackets (Group 1) and without brackets (Group 2). The sample was selected from patients treated at the Faculty of Dentistry, Complutense University of Madrid, Spain. Microbiological assessment was performed in every child and all data were statistically analysed. RESULTS: Group 1 showed significantly higher microbiological values and the difference was greater in lower teeth. Comparing the total plaque percentage, it was significantly higher in Group 1. STATISTICS: there was no significant correlation between gingival and plaque indexes in any group. No significant correlation was found between plaque index and bacteria. CONCLUSION: Children using brackets showed significantly higher gingival and plaque indices than children without brackets. No direct relationship was found between the increase in gingival and plaque indices and the presence and quantity of bacteria; therefore it was not possible to identify specific bacteria as responsible for the high gingival index in patients with brackets.

Antibiotic susceptibility of Staphylococcus aureus isolates in oral mucosa and pockets of patients with gingivitis-periodontitis.

Both oral cavity and subgingival pocket are ecological niches conducive to hosting microorganisms that may act as opportunistic pathogens, such as Staphylococcus aureus and especially methicillin-resistant Staphylococcus aureus (MRSA). Early detection of MRSA is a matter of concern to Public Health. The aim of our study was to determine phenotypic and genotypic detection of methicillin resistance of S. aureus in oral mucosa and subgingival pocket in 102 patients with gingivitis-periodontitis. The prevalence of S. aureus was 10.8% (n = 11) in subgingival pocket and 19.6% (n = 20) in oral mucosa. We obtained 31 isolates of S. aureus of which 13 were mecA positive and 18 were mecA negative. Detection of mecA gene by PCR was used as the reference method to compare the results of phenotypic methods to determine methicillin resistance. Early, accurate detection of S. aureus through phenotyping and genotyping methods is crucial for assessing the colonization and preventing the spread of MRSA.

[Characteristics of microbiocenosis of gingival pocket in patients with chronic generalized periodontitis].

As a result of examination of 56 patients with chronic generalized periodontitis (CGP) of a moderate severity and a severe form of the disease, microflora from gingival pocket in patients which severe form of CGP was established to have higher specific weight in index of dissemination of strains such as Staphylococcus aureus, Streptococcus pyogencs, Enterococcus, Corynebacterium spp., anaerobic bacteria. Strains from patients with a severe form of CGP were characterized by a higher level of expression of the factors of pathogenicity and persistence. Associations of streptococci and staphylococci which the representatives of anaerobic flora such as Bacteroides, Fusobacterium, Prevotella, Clostridium, Peptostreptococcus were more often revealed in patients with a severe form of CGP. Fact of microbial translocation from the gingival pocket was established: from the blood of the patients with CGP of a severe form, strains-translocants were cultivated by 4 times more frequently than from the patients with CGP of a moderate severity.

PCR detection of Streptococcus mutans and Aggregatibacter actinomycetemcomitans in dental plaque samples from Haitian adolescents.

Streptococcus mutans and Aggregatibacter actinomycetemcomitans are oral pathogens associated with dental caries and periodontitis, respectively. The aim of this study was to determine the colonization of these two microorganisms in the dental plaque of a group of Haitian adolescents using two different polymerase chain reaction (PCR) methods, standard PCR, and quantitative real-time PCR (qPCR) assays. Fifty-four pooled supra-gingival plaque samples and 98 pooled sub-gingival plaque samples were obtained from 104 12- to19-year-old rural-dwelling Haitians. The total genomic DNA of bacteria was isolated from these samples, and all participants also received caries and periodontal examinations. Caries prevalence was 42.2%, and the mean decayed, missing, and filled surface (DMFS) was 2.67 ± 5.3. More than half of the adolescents (53.3%) experienced periodontal pockets (Community Periodontal Index score ≥3). S. mutans was detected in 67.3% by qPCR and 38.8% by PCR of the supra-gingival plaque samples (p < 0.01), and 36.6% by qPCR and 8.1% by PCR of the sub-gingival samples (p < 0.01). A. actinomycetemcomitans was detected in 85.1% by qPCR and 44.0% by PCR of the sub-gingival samples (p < 0.01), but the prevalence was similar, 67.3% by qPCR and 59.2% by PCR, in the supra-gingival plaque samples. Neither age nor gender was significantly correlated to the bacterial colonization. The results demonstrated a moderate-to-high prevalence of S. mutans and A. actinomycetemcomitans in the Haitian adolescent population, and qPCR is more sensitive than standard PCR in field conditions. These findings suggest that qPCR should be considered for field oral epidemiologic studies and may be necessary in investigations having major logistic challenges.

Antibiotic susceptibility of Staphylococcus aureus isolates in oral mucosa and pockets of patients with gingivitis-periodontitis

La cavidad bucal y el interior de la bolsa subgingival constituyen nichos ecológicos propicios para albergar microorganismos que podrían actuar como patógenos oportunistas, como el Staphylococcus aureus y enparticular S. aureus resistente a la meticilina (SARM). La detección temprana de portadores reviste importancia para la salud pública. El objetivo de nuestro trabajo fue determinar por métodos fenotípicos y genotípicos la meticilino resistencia de cepas de S. aureus aisladas de mucosa bucal y bolsa subgingival y bolsa subgingival de 102 pacientes con enfermedad gingivoperiodontal. Se observó una prevalencia de S. aureus en bolsa subgingival del 10,8 por ciento (n=11) y en mucosa bucal del 19,5 por ciento (n=20). Se obtuvieron 31 aislamientos de S. aureus de los cuales 13 fueorn mec A positivos y 18 eran mec A negativos. La detección del gen mec A por PCR se utilizó como método de referencia para comparar los resultados de métodos fenotípicos para determinar la resistencia a meticilina. La detección rápida y exacta de S. aureus por métodos microbiológicos fenotípicos y genotípicos es relevante para evaluar la colonización y prevenir la propagación del SARM.

[Dental implant-related infections]. / Infecciones relacionadas con los implantes dentarios.

Dental implant-associated infections are expected to be increasingly more common as the number of patients with implants for more than 10 years rises. There are 2 stages of peri-implant infection: early mucositis, consisting of inflammation of the peri-implant soft tissues without loss of supporting bone, and a more advanced form involving a loss of osseointegration, known as peri-implantitis. The estimated prevalence of this latter infection is 10% of 5-year implants and the main risk factor is previous periodontal disease. The etiopathogenesis of peri-implantitis is related with reservoirs of periodontal pathogens; however factors that lead to colonization of the implant surface or increased susceptibility to infection may also have an influence. Treatment should include removal of the bacterial biofilm, debridement of the exposed surface, and surgical regeneration of the peri-implant pocket.

Clinical and microbiologic changes associated with the combined use of a powered toothbrush and a triclosan/copolymer dentifrice: a 3-year prospective study.

BACKGROUND: Different means are available for self-performed oral hygiene. The aim of this study was to evaluate the clinical and microbiologic effects of a preventive homecare program including the combined use of a powered toothbrush and a triclosan/copolymer-containing dentifrice. METHODS: A total of 160 adult subjects without signs of destructive periodontal disease were recruited for this 3-year randomized controlled trial. The subjects were assigned to a homecare program using an oscillating/rotating powered toothbrush and a triclosan/copolymer/fluoride-containing dentifrice (test) or a manual toothbrush and a standard fluoride-containing dentifrice (control). Supragingival polishing and reinforcement of homecare procedures were provided every 6 months. Plaque, bleeding on probing (BOP), and probing depth (PD) were scored at baseline and after 1, 2, and 3 years. Subgingival plaque samples were taken from the mesial aspect of each tooth at baseline and after 1, 2, and 3 years and were analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. All data analyses were based on "intention-to-treat" with the subject as the statistical unit. RESULTS: Compared to baseline, no significant changes in clinical parameters were observed during the 3 years, except for a reduction in the mean PD at the 2- and 3-year follow-up examinations (P <0.05). No significant differences were found between the two groups with regard to plaque, BOP, or PD or in the mean counts of the 40 species at any time point. CONCLUSION: The study failed to prove additional benefits of the combined use of a powered toothbrush and a triclosan/copolymer-containing dentifrice in adult subjects without signs of destructive periodontal disease.

Profiling of bacterial flora in crevices around titanium orthodontic anchor plates.

OBJECTIVES: The aims of this study were to characterize the microflora in crevices around titanium orthodontic anchor plates using anaerobic culture and molecular biological techniques for bacterial identification, and to compare the microbial composition between crevices around anchor plates and gingival crevices. MATERIAL AND METHODS: Samples from crevices around titanium anchor plates and healthy gingival crevices of 17 subjects (aged 20-29) were cultured anaerobically, and isolated bacteria were identified by 16S rRNA sequencing. RESULTS: The average logarithm colony-forming units/ml were 6.84, 7.51 and 8.88 in healthy anchor plate crevices, inflamed anchor plate crevices and healthy gingival crevices, respectively, indicating that the bacterial density of anchor plate crevices was lower than that of healthy gingival crevices. Of 184 strains isolated from healthy anchor plate crevices of seven subjects, 108 (59%) were anaerobic bacteria, while 73 (40%) were facultative bacteria. Predominant isolates were Gram-negative rods, such as Campylobacter (12%), Fusobacterium (10%) and Selenomonas (10%), and Gram-positive facultative bacteria, such as Actinomyces (17%) and Streptococcus (8.2%). Of 133 strains isolated from inflamed anchor plate crevices of three subjects, 110 (83%) were anaerobic bacteria, while predominant isolates were Gram-negative rods, such as Prevotella (47%), Fusobacterium (33%) and Campylobacter (16%). On the other hand, of 146 strains isolated from healthy gingival crevices of seven subjects, 98 (67%) were facultative bacteria, while 45 (31%) were anaerobic bacteria. Predominant isolates were Gram-positive facultative bacteria, such as Actinomyces (37%) and Streptococcus (20%). CONCLUSIONS: These results suggest that the environment in crevices around titanium orthodontic anchor plates is anaerobic and supportive of anaerobic growth of bacteria, which may trigger inflammation in the tissue around the plates.

Genotypic relatedness of yeasts in thrush and denture stomatitis.

BACKGROUND/AIM: Candida is an opportunistic pathogen. Understanding its genetic characters might increase our understanding of the pathogenesis of candidosis. We examined the genetic relationships of yeasts from the most common forms of oral candidosis: thrush and denture stomatitis. METHODS: Yeasts were sampled from palate, buccal mucosa, gingival sulci/periodontal pockets and/or denture fitting surface of 19 thrush patients and 22 denture stomatitis patients. Random amplified polymorphic DNA and the Dendron computer-assisted program were used to determine the genotypic relatedness of the yeasts. RESULTS: A dendrogram generated from 105 thrush isolates had similarity coefficients (S(AB)) ranging from 0.58 to 1 with four clusters derived at S(AB) 68%. Another dendrogram was generated from 91 isolates from denture stomatitis, with S(AB) ranging from 0.59 to 1. Three clusters were established at S(AB) 71%. In a composite dendrogram incorporating the thrush and denture stomatitis data and orally healthy data compiled from a previous study, five genotypic clusters were generated at S(AB) 68%. Cluster II, the most dominant, comprised isolates from thrush, denture stomatitis and healthy conditions, while clusters III and IV contained yeasts mainly from thrush. CONCLUSIONS: Palatal yeast carriage was significantly increased in thrush and denture stomatitis, also after radiation, chemotherapy and denture wearing. The buccal mucosa was favorable for yeast colonization regardless of oral condition. Yeasts in thrush were more diverse than in conditions of oral health. The common clone (II) of infecting yeasts and commensals suggested that commensals could induce thrush and denture stomatitis, whereas the unique clones in thrush (III, IV) might have been established through strain replacement or maintenance with minor genetic variation.

Sulcular sulfide monitoring: an indicator of early dental plaque-induced gingival disease.

PURPOSE: The purpose of this study was to evaluate the relationship between volatile sulfur compounds (VSC) and gingival health status and to determine if volatile sulfur compounds can detect early dental plaque-induced gingival disease. METHODS: A split-mouth design with randomly selected quadrants of the mandibular arch enabled 39 participants to serve as their own controls. At baseline and at three subsequent appointments (days 7, 14, and 21) gingival inflammation (GI), bleeding on probing (BOP), and sulfide levels (SUL) were measured using the Gingival Index and the Diamond Probe/Perio 2000 System. For three weeks, participants refrained from brushing and flossing one randomly selected quadrant of the mandibular arch. The Pearson correlation test was used to determine the relationship between sulfide concentrations and gingival health. The Wilcoxon signed rank test was used to compare the differences in mean GI, BOP, and SUL scores between the hygiene side (H) and the non-hygiene side (NH). RESULTS: Data suggest that SUL correlate positively to GI and BOP on both sides; however, the strength of the correlation was stronger for the NH side. A comparison of mean GI, BOP, and SUL scores revealed a statistically significant difference between sides for all three parameters from baseline to day 21, except for SUL on day 14. CONCLUSIONS: Based on study outcomes, the Diamond Probe/Perio 2000 System demonstrated the ability to detect sites with elevated SUL; therefore, SUL may be a useful adjunctive indicator of early plaque-induced gingivitis. In addition, data revealed a moderate correlation between SUL levels and gingival inflammation on the NH sides. Whether sulfur by-product is a contributor to the disease process, or merely a correlate, is inconclusive.

Influence of nicotine and cotinine on epithelial colonization by periodontopathogens.

BACKGROUND: Since smoking is an established risk factor for the development of periodontitis, the present study investigated whether nicotine and cotinine can make epithelial cells more prone to colonization by periodontopathogens. METHODS: Primary epithelial cell mono-layers were inoculated with nicotine and cotinine prior to adhesion experiments with Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. The number of bacteria associated with cells inoculated or not with nicotine or cotinine were assessed by an indirect culture viability assay. The same experimental set-up was used for assessing HeLa cells exposed to cigarette smoke extract (CSE). RESULTS: Primary epithelial cells inoculated with concentrations of nicotine and cotinine, found in smokers and non smokers, did not show significant differences (P>0.05) in colonization susceptibility to A. actinomycetemcomitans. When these concentrations were increased to 1 mg/ml, a significant (P<0.05) and species-specific effect of the colonization susceptibility of epithelial cells was observed: It increased for A. actinomycetemcomitans, while it decreased for P. gingivalis. For both species the effects were more pronounced for nicotine, although this was not statistically significant. The change in colonization susceptibility did not result from alterations of the bacterial viability due to nicotine or cotinine. Treatment of HeLa cells with CSE also led to a species-specific variation in colonization tendency; i.e., increased for A. actinomycetemcomitans (P<0.05), but not for P. gingivalis. CONCLUSIONS: The susceptibility of epithelial cells to become colonized by either A. actinomycetemcomitans or P. gingivalis could be altered by nicotine, cotinine, or CSE in a time-dependent, species-specific manner. Whether these findings that support the hypothesis of an increased patient susceptibility for bacterial adhesion to epithelial cells in smokers are clinically relevant remains to be proven.

Bacteremia following surgical dental extraction with an emphasis on anaerobic strains.

Our aim was to investigate bacteremia caused by surgical extraction of partly erupted mandibular third molars. From 16 young adults, bacterial samples were taken from the third-molar pericoronal pocket and post-operatively from the extraction socket, and blood samples were drawn from the ante-cubital vein up to 30 min after surgery. Of the subjects, 88% had detectable bacteremia-50% 1 min after the incision, 44% immediately after extraction. The respective percentages at 10, 15, and 30 min were 44%, 25%, and 13%. Blood cultures contained 31 species (74% anaerobes), with 3.9 +/- 2.6 species isolated per subject. Most prevalent were the anaerobes Prevotella, Eubacterium, and Peptostreptococcus sp. and the aerobes viridans-group streptococci and Streptococcus milleri group. Any species found in the blood was also isolated from the mouth, from 93% of the pericoronal pockets and from 43% of the extraction sockets. Surgical dental extraction clearly causes bacteremia of a high frequency and lasting longer than thus far assumed.