The predominant cultivable flora of tooth surface plaque removed from institutionalized subjects

Necrotizing Gingivitis: Microbial Diversity and Quantification of Protein Secretion in Necrotizing Gingivitis

Necrotizing gingivitis (NG) is a necrotizing periodontal disease that differs from chronic gingivitis (CG). To date, both the microbiological causes and the involved host cytokine response of NG still remain unclear. Here, we investigated corresponding interdental plaque and serum samples from two groups of Chinese patients with CG (n = 21) or NG (n = 21). The microbiota were studied by 16S rRNA Illumina MiSeq sequencing of the microbial metagenome and by assessing quantitatively the abundance of the phylum Bacteroidetes, the genus Prevotella and the species T. forsythia, P. endodontalis, and P. gingivalis using fluorescence in situ hybridization (FISH). With respect to the associated host response, the levels of 30 inflammatory mediators were quantified by multiplex immunoassay analysis. Differential microbial abundance analysis of the two disease groups revealed at the phylum level that Proteobacteria accounted for 67% of the differentially abundant organisms, followed by organisms of Firmicutes (21%) and Actinobacteria (9%). At the species level, significant differences in abundance were seen for 75 species of which 58 species were significantly more abundant in CG patients. Notably, the FISH analysis revealed that Bacteroidetes was the most prevalent phylum in NG. The multiplex cytokine assay showed significant quantitative differences between the disease groups for eight analytes (GM–CSF, G–CSF, IFN–α, IL–4, IL–13, TNF–α, MIG, and HGF). The G–CSF was found to be the most significantly increased inflammatory protein marker in NG. The next-generation sequencing (NGS) data supported the understanding of NG as a multi-microbial infection with distinct differences to CG in regard to the microbial composition.

Toothpastes with Enzymes Support Gum Health and Reduce Plaque Formation

Enzymes in toothpastes can support host immune responses, and thus maintain oral health. This study aimed to investigate gingival health and the plaque-reducing effects of enzyme-containing toothpastes. A laboratory study tested the antimicrobial potential of different enzyme-containing toothpaste formulations. Two promising formulations (enzyme-containing toothpastes with glucose oxidase and D-glucose with (C+) and without Citrox (C-) Citrox) were investigated in a clinical crossover trial (two slurries: sodium lauryl sulfate-containing (SLS), a toothpaste without SLS (reference), and water). Subjects (n = 20) abstained from toothbrushing for four days and rinsed with a toothpaste slurry. Bleeding on probing (BOP) and plaque indices (PI) were measured. A mixed linear model was used to statistically compare the slurries with respect to BOP and PI change. The in vitro bacterial growth-inhibiting evaluation showed the best results for SLS, followed by C+ and C-. The change in BOP and PI exhibited statistically significant differences to water rinsing (BOP; PI changes in % points (difference of the baseline and post-rinse values: water = 8.8%; 90.0%; C+ = -1.4%; 80.4%; SLS = 1.5%; 72.1%; reference = 0.8%; 77.5%; C- = -1.8%; 75.1%). All slurries exhibited anti-gingivitis and anti-plaque effects, resulting in a prophylactic benefit for limited-access regions during brushing.

Polymicrobial oral biofilm models: simplifying the complex

Over the past century, numerous studies have used oral biofilm models to investigate growth kinetics, biofilm formation, structure and composition, antimicrobial susceptibility and host-pathogen interactions. In vivo animal models provide useful models of some oral diseases; however, these are expensive and carry vast ethical implications. Oral biofilms grown or maintained in vitro offer a useful platform for certain studies and have the advantages of being inexpensive to establish and easy to reproduce and manipulate. In addition, a wide range of variables can be monitored and adjusted to mimic the dynamic environmental changes at different sites in the oral cavity, such as pH, temperature, salivary and gingival crevicular fluid flow rates, or microbial composition. This review provides a detailed insight for early-career oral science researchers into how the biofilm models used in oral research have progressed and improved over the years, their advantages and disadvantages, and how such systems have contributed to our current understanding of oral disease pathogenesis and aetiology.

Community analysis of dental plaque and endotracheal tube biofilms from mechanically ventilated patients

PURPOSE

Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations.

MATERIAL AND METHODS

Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed.

RESULTS

No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance.

CONCLUSION

The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group.

Interproximal biofilm removal by intervallic use of a sonic toothbrush compared to an oral irrigation system

BACKGROUND

The purpose of this in-vitro study was to investigate the potential of biofilm removal in interproximal tooth regions using intervallic cleaning with an oral irrigator or a sonic toothbrush.

METHODS

Three-species biofilms (Streptococcus mutans (OMZ 918), Streptococcus oralis SK 248 (OMZ 60), Actinomyces naeslundii (OMZ 745)) were grown on hydroxyapatite discs for 3 days in culture media. Every 24 h, specimens were incubated for 15 min in resazurin solution (i.e., culture medium and 10 % v/v alamarBlue®) to measure the metabolic activity with a fluorescence spectrophotometer in relative fluorescence units (rfu) at baseline. Then, specimens were fixed in interproximal holding devices and underwent treatment with an oral irrigator (WF; Waterpik® Sensonic WP-100E), an active sonic toothbrush (WPa), or an inactive sonic toothbrush (WPi; Waterpik® Sensonic SR-3000E) for 10 s (n = 18/group). Untreated biofilms served as controls (CO). After treatment, bacterial activity was re-measured, and specimens were re-grown in fresh medium for 24 h until next cleaning procedure. Altogether, cleaning was repeated in intervals of three treatment days (d1, d2, d3). After d3, SEM images were taken (n = 8) and CFU was measured (n = 3). Metabolic activity was analyzed for each disc separately, rfu values were averaged for d1 to compare initial biofilm stability, and ratios of baseline and post-treatment values were compared. Results were analyzed using ANOVA with the post-hoc Scheffé test, or Kruskal-Wallis with post-hoc Mann-Whitney test.

RESULTS

Median baseline rfu-values of d1 resulted in 7821.8 rfu (interquartile range = 5114.5). Highest reduction in metabolic activity was recorded significantly for the oral irrigator used for 10 s (residual activity per day d1: WF 17.9 %, WPa 58.8 %, WPi 82.5 %, CO 89.6 %; d2: WF 36.8 %, WPa 85.2 %, WPi 82.5 %, CO 90.0 %; d3: WF 17.2.%, WPa 79.6 %, WPi 96.3 %, CO 116.3 %). SEM images of untreated specimens (CO) and specimens treated with the sonic toothbrush (WPa and WPi) showed huge amounts of biofilm, while oral irrigator-treated specimens (WF) revealed barely any bacteria. CFU data confirmed the graduations between the groups.

CONCLUSIONS

Cleaning of interproximal regions achieved better success with an oral irrigator as compared to the use of a sonic toothbrush. (350/350 words).

In vitro method for prediction of plaque reduction by dentifrice

An in vitro Particle Based Biofilm (PBB) model was developed to enable high throughput screening tests to predict clinical plaque reduction. Multi-species oral biofilms were cultured from pooled stimulated human saliva on continuously-colliding hydroxyapatite particles. After three days PBBs were saline washed prior to use in screening tests. Testing involved dosing PBBs for 1min followed by neutralization of test materials and rinsing. PBBs were then assayed for intact biofilm activity measured as ATP. The ranking of commercial dentifrices from most to least reduction of intact biofilm activity was Crest ProHealth Clinical Gum Protection, Crest ProHealth, Colgate Total and Crest Cavity Protection. We demonstrated five advantages of the PBB model: 1) the ATP metric had a linear response over ≥1000-fold dynamic range, 2) potential interference with the ATP assay by treatments was easily eliminated by rinsing PBBs with saline, 3) discriminating power was statistically excellent between all treatment comparisons with the negative controls, 4) screening test results were reproducible across four tests, and 5) the screening test produced the same rank order for dentifrices as clinical studies that measured plaque reduction. In addition, 454 pyrosequencing of the PBBs indicated an oral microbial consortium was present. The most prevalent genera were Neisseria, Rothia, Streptococcus, Porphyromonas, Prevotella, Actinomyces, Fusobacterium, Veillonella and Haemophilus. We conclude these in vitro methods offer an efficient, effective and relevant screening tool for reduction of intact biofilm activity by dentifrices. Moreover, dentifrice rankings by the in vitro test method are expected to predict clinical results for plaque reduction.

Conventional caries removal and sealed caries in permanent teeth: a microbiological evaluation

OBJECTIVES

The aim of this study was to compare microbiological infection after conventional carious dentine removal with incomplete carious dentine removal and sealing.

METHODS

Eighty-seven patients (12-50 years of age) under treatment at the Dental Clinics of the Federal University of Rio Grande do Sul (UFRGS), Brazil, participated in the study. The patients presented 90 posterior permanent teeth with primary caries. The lesions were coronal, active, and reached at least the middle third of the dentine. None of the teeth exhibited spontaneous pain, sensitivity to percussion or apical pathology (detected through radiographic exams). Pulp sensibility was confirmed by the cold test. The lesions were divided into 2 experimental groups: complete caries removal (CCR) based on hardness criteria (n=60 lesions) and incomplete caries removal (ICR) and sealing (n=32 lesions). Microbiological samples were obtained from the initial demineralized dentine, after CCR and after ICR-Seal.

RESULTS

The number of anaerobic and aerobic bacteria, lactobacilli, and mutans streptococci decreased at the end of treatment (p<0.05). Significantly less anaerobic bacteria (p<0.01), aerobic bacteria (p=0.02), and mutans streptococci (p<0.01) growth was observed after ICR-Seal compared to CCR. The difference in lactobacilli was insignificant (p=0.08). The amount of bacteria detected after conventional caries removal was higher than that which remained in sealed caries lesions.

CONCLUSIONS

The results suggest it is not necessary to remove all carious dentine before the restoration is placed because over time, sealing of carious dentine results in lower levels of infection than traditional dentine caries removal.

CLINICAL SIGNIFICANCE

The results of this study indicate that sealed carious dentine was less infected than the remaining dentine left after conventional caries removal and sealing. Our results support treatment of deep carious lesions in one session with incomplete removal of carious dentine.

Dental caries in rats associated with Candida albicans

In addition to occasional opportunistic colonization of the oral mucosa, Candida albicans is frequently found in carious dentin. The yeast's potential to induce dental caries as a consequence of its pronounced ability to produce and tolerate acids was investigated. Eighty caries-active Osborne-Mendel rats were raised on an ampicillin-supplemented diet and exposed to C. albicans and/or Streptococcus mutans, except for controls. Throughout the 28-day test period, the animals were offered the modified cariogenic diet 2000a, containing 40% various sugars. Subsequently, maxillary molars were scored for plaque extent. After dissection, the mandibular molars were evaluated for smooth surface and fissure caries. Test animals exposed to C. albicans displayed considerably more advanced fissure lesions (p < 0.001) than non-exposed controls. While S. mutans yielded similar results, a combined association of C. albicans and S. mutans had no effect on occlusal caries incidence. Substituting dietary sucrose by glucose did not modify caries induction by C. albicans. However, animals fed a diet containing 20% of both sugars showed no differences to non-infected controls. Smooth surface caries was not generated by the yeast. This study provides experimental evidence that C. albicans is capable of causing occlusal caries in rats at a high rate.

Clinical, salivary, and bacterial markers for caries risk assessment in schoolchildren: a 4-year follow-up

BACKGROUND

In Mexico, there is a high prevalence of dental caries and large groups of children still show extensive untreated dental damage.

AIM

This study aims to evaluate, in a cohort of 6-year-old Mexican children, the relationship between caries increment at 4 years and the following caries risk markers: fissure morphology, caries experience, salivary flow rate, Snyder test results, and mutans and lactobacilli counts.

DESIGN

To predict new caries lesions in 110 schoolchildren, clinical, salivary, and bacteriological caries risk markers were used, including fissure morphology, caries experience, salivary flow rate, Snyder test, and Streptococcus mutans and lactobacilli counts. To determine the validity of these markers, the baseline data were compared with the caries increment after 4 years.

RESULTS

The risk model's capacity to predict caries was moderate (specificity 79.6% and sensitivity 78.6%). Caries experience (P = 0.0001), Snyder test (P = 0.002), and fissure morphology (P = 0.024) had the strongest association with caries increment. Salivary flow rate, lactobacilli, and S. mutans counts did not contribute significantly to the prediction of caries lesions in these children.

CONCLUSION

In addition to the initial caries experience, tooth morphology and Snyder test proved to be useful predictors for caries. These three risk markers may be particularly useful in targeting caries prevention efforts in developing countries.

Laboratory maintenance of Treponema denticola

This unit describes the methods, media, and equipment necessary for routine laboratory culture and handling of the anaerobic oral spirochete Treponema denticola. Topics discussed include nutrient requirements, recommended media formulations, and expected growth kinetics, as well as methods and equipment necessary to maintain anaerobic conditions. An additional protocol on isolation of T. denticola from clinical samples is included.

Laboratory maintenance of fusobacteria

This unit describes routine laboratory handling of fusobacteria. Different media that can be used to grow or enrich Fusobacterium nucleatum and other species of this genus are described. The growth and stock conditions as well as the susceptibility of F. nucleatum to oxygen in a pure culture are also discussed.

Periodontal microflora of HIV infected patients with periodontitis

The aim of this study was to determine the microbial profile of periodontal lesions in HIV seropositive patients and to compare it with rapidly progressing periodontal lesions in systemically healthy patients. The subgingival microflora of 20 CDC II, 20 CDC III, 20 CDC IV/V and 20 systemically healthy patients with rapidly progressing periodontitis was examined. Four sites with greatest probing depth in each patient were selected for microbiological sampling. The samples were cultured aerobically and anaerobically for bacterial isolation using selective and non-selective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. The microflora of periodontitis lesions within the three stages of the HIV infection was similar to that of progressing periodontitis in systemically healthy adults including Campylobacter rectus, Capnocytophaga spp., Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Selenomonas spp. and Peptostreptococcus micros. However, HIV seropositive periodontitis lesions harboured a range of exogenous pathogens rarely associated with common types of periodontitis including Staphylococcus aureus, Enterobacter cloaca, Pseudomonas aeruginosa, Candida albicans, Enterococcus faecalis, Enterococcus avium, Clostridium difficile, Aspergillus fumigatus, Klebsiella pneumoniae and Mycoplasma incognitum. The lack of immune effector and regulatory cells in HIV infected patients could in fact explain the increase of some opportunistic pathogens and the characteristic and rapidly progressing nature of the periodontal disease in these patients.

Subgingival microflora in smokers with early onset periodontitis

Cigarette smoking is a potent risk factor which has recently been associated with periodontal disease progression. The objective of this study was to detect the microbial profile of early onset periodontitis in smokers and compare it to that of non-smokers. The study population consisted of 50 systemically healthy individuals aged 25 to 38 years, exhibiting early onset periodontitis. 25 patients were smokers (> 20 cigarettes/day) and 25 non-smokers. Two pooled bacterial samples comprised of four periodontal sites with probing depth > 5 mm each, were collected from each individual. The samples were cultured aerobically and anaerobically for bacterial isolation using selective and non-selective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. The differences in bacterial counts using the Mann Whitney U test were statistically significant for Staphylococcus aureus, Campylobacter concisus, Eikenella corrodens, Escherichia coli, Bacteroides forsythus, Bacteroides gracilis, Campylobacter rectus, Porphyromonas gingivalis, Selenomonas sputigena and Candida albicans in smokers. Statistically significant differences for Peptostreptococcus micros, Actinomyces naeslundii, Eubacterium lentum and Capnocytophaga gingivalis were detected in non-smokers. The isolation of bacteria belonging to the exogenous flora like E. coli, C. albicans and S. aureus in smokers microflora underscores the importance of the host which is adversely affected by cigarette smoking.

Efficacy of gasiform ozone and photodynamic therapy on a multispecies oral biofilm in vitro

Ozone gas and photodynamic therapy (PDT) have been claimed to be antimicrobially effective. This study assessed their antimicrobial potential in vitro. Mature six-species oral biofilms were treated as follows (n = 9 per group): (i) a 60-s application of gasiform vacuum-ozone or vacuum alone (on wet or air-dried biofilm samples); (ii) PDT (i.e. methylene blue in combination with or without a diode soft laser, and a soft laser alone); or (iii) antimicrobial solutions: immersion of biofilms for 60 s in 0.2 and 2% chlorhexidine or in 0.5 and 5% hypochlorite solution. Treatment with chlorhexidine or hypochlorite served as a positive control, whereas untreated samples served as negative controls. Colony-forming units on blood agar were counted. Only the 5% hypochlorite solution was able to totally eliminate the microorganisms in the biofilm. The observed reduction of viable counts by vacuum-ozone application and PDT was less than one log(10) step. Under the conditions of the current study, gasiform ozone and PDT had a minimal effect on the viability of microorganisms organized in a cariogenic biofilm.

In vivo evaluation of microbial reduction after chemo-mechanical preparation of human root canals containing necrotic pulp tissue

AIM

To determine in vivo, the degree of microbial reduction after chemo-mechanical preparation of human root canals containing necrotic pulp tissue when using two endodontic irrigating reagents, sodium hypochlorite (NaOCl) or chlorhexidine gel (CHX).

METHODOLOGY

Thirty-two single rooted teeth with necrotic pulp were divided into two groups. One group (n=16) was irrigated with 2.5% NaOCl, whilst the other group (n=16) was irrigated with 2% CHX gel. Assessment of the bacterial load was accomplished by use of real-time quantitative-polymerase chain reaction (RTQ-PCR) directed against the small subunit ribosomal DNA using the SYBRGreen and TaqMan formats. Statistical analysis was performed using the Mann-Whitney test. For contrast, bacterial load was also determined by traditional culture techniques.

RESULTS

The bacterial load was reduced substantially in both groups (over 96%). However, using RTQ-PCR the bacterial load before and after chemo-mechanical preparation was greater when compared with evaluation using colony forming units (CFU). Furthermore, as measured by RTQ-PCR, the bacterial reduction in the NaOCl-group (SYBRGreen 99.99%; TaqMan: 99.63%) was significantly greater (P<0.01) than in the CHX-group (SYBRGreen 96.62%; TaqMan: 96.60%). According to culture technique 75% of cases were free of bacteria after chemo-mechanical preparation in the NaOCl-group, whilst 50% of cases were bacteria free in the CHX-group.

CONCLUSION

NaOCl has not only a higher capacity to kill microorganisms but is also more able to remove cells from the root canal.

Genotypic and phenotypic characterization of fusobacteria from Chinese and European patients with inflammatory periodontal diseases

Phylogenetic and antigenic studies were performed on 48 human oral Fusobacterium strains from Chinese patients with either necrotizing ulcerative gingivitis (NUG) or gingivitis and on 23 Fusobacterium nucleatum or Fusobacterium periodonticum strains from European periodontitis patients. Alignment of partial 16S rRNA gene sequences resulted in a phylogenetic tree that corresponded well with the current classification of oral fusobacteria into F. periodonticum and several subspecies of F. nucleatum, in spite of much minor genetic variability. F. periodonticum, F. nucleatum subsp. animalis and a previously undescribed phylogenetic cluster (C4), that may represent an additional F. nucleatum subspecies, constituted discrete clusters distinct from the remainder of F. nucleatum with high bootstrap values. Chinese and European strains differed markedly with regard to their respective classification patterns, suggesting a predominance of F. peridonticum and F. nucleatum susp. animalis over F. nucleatum subsp. nucleatum and F. nucleatum subsp. fusiforme/vincentii in samples from China. Antigenic typing enabled the association of many previously described serovars with distinct phylogenetic clusters and when applied directly to uncultured clinical samples confirmed the differential distribution of oral Fusobacterium taxa in Chinese and European samples. Bacteria from cluster C4 and F. nucleatum subsp. animalis were significantly more prevalent and accounted for higher cell numbers in NUG than in gingivitis samples, suggesting a possible association of these rarely observed taxa with NUG in Chinese patients.

Guggenheimella bovis gen. nov., sp. nov., isolated from lesions of bovine dermatitis digitalis

Dermatitis digitalis is an economically important ulcerative disease of undetermined aetiology affecting the hooves of cattle. Material was examined from two independent cases of this disease in Switzerland. Cultures from the advancing front of both lesions yielded large numbers of closely related short, mesophilic, non-motile, non-spore-forming, anaerobic, proteolytic, Gram-positive rods. The 16S rRNA gene sequences of strains OMZ 913(T) and OMZ 915 were identical and indicate Tindallia magadiensis and Eubacterium saphenum as their closest relatives. Phenotypically, the novel isolates are clearly distinguished from related bacteria by protein and antigen patterns, by cellular fatty acids and by API ZYM activities. The diamino acid of the Gram-positive cell wall is ornithine and the G+C content of OMZ 913(T) DNA is 44.4 mol%. The phylogenetic distance from recognized taxa in the phylum Firmicutes is sufficient to place these bovine isolates into a novel genus and species, for which the name Guggenheimella bovis gen. nov., sp. nov. is proposed, with OMZ 913(T) (=CIP 108087(T)=DSM 15657(T)) as the type strain.

Clinical trial of a plant-derived antibody on recolonization of mutans streptococci

OBJECTIVE

This double-blinded, placebo-controlled clinical trial tested the safety and efficacy of a topical secretory IgA antibody manufactured in tobacco plants (plantibody) in preventing recolonization of mutans streptococci (MS) in human plaque as measured by whole stimulated saliva samples.

METHODS

Following a 9-day antimicrobial treatment with chlorhexidine (CHX), 56 eligible adults (enrollment salivary MS > or = 10(4) CFU/ml; no current caries) were randomized equally to a group receiving 0, 2, 4, or 6 topical applications of plantibody followed by 6, 4, 2, or 0 applications of placebo, respectively, over a 3-week period.

RESULTS

Among the 54 subjects who completed the trial, the CHX regimen eliminated salivary MS in 69%. After 6 months, there were no significant differences in MS levels by number of applications, relative to placebo (p > 0.43). No adverse effects were observed.

CONCLUSION

Plantibody is safe but not effective at the frequency, concentration, and number of applications used in this study.

Persistence of Streptococcus mutans in stationary-phase batch cultures and biofilms

Streptococcus mutans is a member of oral plaque biofilms and is considered the major etiological agent of dental caries. We have characterized the survival of S. mutans strain UA159 in both batch cultures and biofilms. Bacteria grown in batch cultures in a chemically defined medium, FMC, containing an excess of glucose or sucrose caused the pH to decrease to 4.0 at the entry into stationary phase, and they survived for about 3 days. Survival was extended up to 11 days when the medium contained a limiting concentration of glucose or sucrose that was depleted by the time the bacteria reached stationary phase. Sugar-limited cultures maintained a pH of 7.0 throughout stationary phase. Their survival was shortened to 3 days by the addition of exogenous lactic acid at the entry into stationary phase. Sugar starvation did not lead to comparable survival in biofilms. Although the pH remained at 7.0, bacteria could no longer be cultured from biofilms 4 days after the imposition of glucose or sucrose starvation; BacLight staining results did not agree with survival results based on culturability. In both batch cultures and biofilms, survival could be extended by the addition of 0.5% mucin to the medium. Batch survival increased to an average of 26 (+/-8) days, and an average of 2.7 x 10(5) CFU per chamber were still present in biofilms that were starved of sucrose for 12 days.

Microbiological profile of early onset/aggressive periodontitis patients

OBJECTIVES

The objectives of this study were to characterize the bacterial profile and to seek possible bacterial associations in the subgingival microbiota of early onset periodontitis/aggressive periodontitis patients by using two different techniques, culture and immunofluorescence.

MATERIAL AND METHODS

The study group consisted of 66 systemically healthy individuals with evidence of early onset periodontitis - 41 females and 25 males aged 23-35 years (mean 31.1 +/- 3.1 years). Bacterial samples were collected from the deepest site in each quadrant, resulting in a total of 264 sites with a mean probing pocket depth of 6.6 +/- 1.5 mm. Samples were cultured anaerobically and in 10% CO(2) using selective and nonselective media, and isolates were characterized to species level. Indirect immunofluorescence using monoclonal antibodies was applied to detect Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia (Bacteroides forsythus, Tannerella forsythensis), Prevotella intermedia/Prevotella nigrescens, Campylobacter rectus, Peptostreptococcus micros and Actinomyces israelii.

RESULTS

93.6% of sampled sites showed bleeding on probing and 23.5% were positive for suppuration. P. intermedia/P. nigrescens, P. gingivalis, and C. rectus were detected in 77.3-85.9% of samples using culture methods and in 85.6-91.3% using immunofluorescence. P. micros and A. actinomycetemcomitans were found, respectively, in 63.3% and 25.0% of all sites using culturing and in 58.7% and 27.7% sites using immunofluorescence. Significantly strong positive associations were observed between T. forsythia and C. rectus (odds ratio 109.46), and T. forsythia and P. gingivalis (odd ratio 90.26), whereas a negative association was seen between P. intermedia/P. nigrescens and A. actinomycetemcomitans (odds ratio 0.42). Coinfection by P. gingivalis, T. forsythia, P. intermedia/P. nigrescens and C. rectus was observed in 62.1% of the test sites, and in 89.4% of the studied subjects. The sensitivity of immunofluorescence for T. forsythia, C. rectus, P. intermedia/P. nigrescens and P. gingivalis was found to be very high (0.99-0.94) using culture as the reference detection method. The agreement between culture and immunofluorescence in detecting the presence or absence of the investigated species was 85.2-88.1% for P. gingivalis, P. intermedia/P. nigrescens, C. rectus, and T. forsythia, 75.9% for A. actinomycetemcomitans and 70.4% for P. micros.

CONCLUSIONS

The microbial profile of the early onset/aggressive periodontitis population was complex. The agreement between the two detection methods was very high.

The use of topical fluoride to prevent or reverse dental caries

Topical fluoride has been the main stay of caries prevention for many decades. There are several mechanisms which make it beneficial including inhibiting demineralization, enhancing remineralization, and inhibiting bacterial growth. Topical fluoride is available in many different forms. The concentrations of various fluoride preparations range from 225 parts per million (ppm) fluoride in over-the-counter oral rinses to 22,600 ppm in the fluoride varnishes. The clinician must decide which type of topical preparation is best suited for their patient. Patients with high caries risk may benefit from prescription strength fluorides (along with the other chemical and dietary therapies described in this issue of Special Care in Dentistry). The application of fluoride varnish is an excellent topical form for those patients who have access to dental care and for whom it is difficult to comply with the use of other topical forms.

Gingival crevice microbiota from Chinese patients with gingivitis or necrotizing ulcerative gingivitis

The objective of this study was to quantitatively compare the bacterial population structure in plaque from the gingival margin of two groups of 21 Chinese patients with gingivitis or necrotizing ulcerative gingivitis (NUG). Subjects were recruited in four dental clinics in Eastern China. Samples were quantitatively assessed by immunofluorescence and fluorescent in situ hybridization for taxa known to be associated with periodontal diseases. The analyses showed that the fusiform taxa (Fusobacterium nucleatum/Fusobacterium periodonticum, Leptotrichia buccalis, Tannerella forsythensis, and Capnocytophaga sp.), Campylobacter rectus, Prevotella intermedia, Prevotella nigrescens, Selenomonas sputigena, and treponemes were present in both groups with high prevalence. Porphyromonas gingivalis and Actinomyces gerencseriae were much more prevalent in the NUG group. Quantitatively, most taxa, including P. gingivalis, F. nucleatum and the treponemes, accounted, on average, for < 3% of the total bacterial cell number. Only P. intermedia/P. nigrescens, P. gingivalis, S. sputigena, A. gerencseriae, and the sum of all monitored suspected periodontal pathogens were significantly increased in the NUG group. The present study demonstrates for both groups a highly diverse plaque composition and suggests that, etiologically, the overall concentration and the concerted effects of the entire group of opportunistic pathogens thriving in NUG-associated plaque are of prime importance.

Estimates, from salivary analyses, of the turnover time of the oral mucosal epithelium in humans and the number of bacteria in an edentulous mouth

The objectives were to obtain rough estimates of the number of bacteria in an edentulous mouth and the mean turnover time of the oral mucosa and the conditions under which the salivary phase in the mouth might act as a bacterial continuous culture system. The premise was that at steady state in vivo, the rates of loss of bacteria and epithelial cells in saliva must be equal to their rates of proliferation. Drooled saliva was collected from 17 subjects and the number of epithelial cells per millilitre was determined in a Coulter Counter. The numbers of adherent bacteria per epithelial cell were counted on cells stained with Toluidine Blue. For 10 subjects, salivary bacterial counts were obtained after saliva had been diluted in Reduced Transport Fluid and grown anaerobically on Blood Agar for 5 days. From the known surface areas of the oral mucosa and individual epithelial cells and the rate of loss of epithelial cells into saliva, the surface layer of epithelial cells was calculated to be replaced every 2.7h. From the calculated number of epithelial cells lining the oral mucosa, the number of bacteria per epithelial cell, and the rate of swallowing of the bacteria in saliva, the number of bacteria in an edentulous mouth was calculated to be about 1.58 x 10(9) and the mean time between bacterial cell divisions to be 1.38h. Given a residual volume of 0.8ml and a maximal bacterial division rate of 3h(-1), the salivary phase in the mouth could act as a continuous culture system for certain fast-growing bacteria only if the maximum flow rate were <0.04ml/min.

Influences of orthodontic appliances on oral populations of mutans streptococci

A study was conducted to assess the influence of fixed appliances on the mutans streptococcal in a group of patients receiving orthodontic treatment. Mutans streptococcal counts in stimulated saliva of 27 patients were obtained at baseline, and at 1-month intervals for 4 months. The difference in mutans streptococcal counts at baseline and at the 4-month sampling was less than an order of magnitude in 18 of the patients, between 1 and 2 orders of magnitude in eight of the patients, and 3 orders of magnitude in one patient. Restriction endonuclease digests of genomic DNA from representative mutans streptococci isolates taken from baseline and 4-month saliva samples, as well as from 4-month tooth and appliance surfaces, were examined by pulsed field gel electrophoresis, after restriction endonuclease digestion. Results of the DNA banding patterns associated with isolates from 19 patients showed that, for 12 patients, all isolates examined represented the same clone of Streptococcus mutans, whereas for six patients two different S. mutans clones were detected. One patient yielded three different clones of S. mutans. A much larger number of baseline, as well as post-appliance, isolates will have to be examined from each patient in future studies, in order to determine if the number of different S. mutans clones harbored by individual patients is related to orthodontic treatment.

Association of early onset periodontitis microbiota with aspartate aminotransferase activity in gingival crevicular fluid

OBJECTIVES

The objective of this study was to determine the relationship between the activity of the enzyme aspartate aminotransferase (AST) in gingival crevicular fluid (GCF) using the colorimetric PerioGard (PTM) test and the subgingival microflora in early onset periodontitis lesions.

MATERIAL AND METHODS

The study population consisted of 25 otherwise healthy individuals exhibiting early onset periodontitis (EOP). In each patient four experimental sites were identified comprising one deep periodontal pocket (PD >5 mm) randomly chosen in each quadrant. Bacterial samples were obtained from the experimental sites, consecutively cultured anaerobically and in 10% CO(2) using selective and nonselective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. Clinical measurements as well as AST activity, assessed either as positive or negative using the PTM, were recorded at the same sites.

RESULTS

Sixty-two sites exhibited AST positive and 38 AST negative activity. Analysis of bacterial counts using the ANOVA (Mann Whitney U-test) showed that Streptococcus intermedius, Peptostreptococcus micros, Campylobacter concisus, Bacteroides forsythus, Camplobacter gracilis, Campylobacter rectus and Selenomonas sputigena were significantly higher in sites with AST-positive activity. The odds ratio of having high prevalence of S. intermedius, P. micros, C. concisus, B. forsythus, C. gracilis, C. rectus and S. sputigena in the presence of a positive AST site was very high (range: 3.5-17.0). Streptococcus sanguis, Actinomyces naeslundii, Gemella morbillorum, Capnocytophaga gingivalis, Veillonella parvula, Fusobacterium varium, Eubacterium lentum and Prevotella oralis were detected in significantly higher proportions in sites with AST negative activity and manifested a negative odds ratio in the presence of AST positive sites. The logistic regression analysis revealed that smoking and bleeding upon probing showed a significant association with AST activity, while plaque and suppuration were not found to be significant predictors of AST activity. The co-infection of Porphyromonas gingivalis, B. forsythus and P. micros, or P. gingivalis, B. forsythus and C. rectus were found to be significantly associated with the AST activity (p<0.001). AST positive sites revealed significantly higher occurrence of co-infections by P. gingivalis, B. forsythus, S. sputigena or by P. gingivalis, B. forsythus, S. intermedius than AST negative sites (p<0.001). P. gingivalis, B. forsythus, A. naeslundii co-infection was found significantly higher in the AST negative sites (p<0.001).

CONCLUSIONS

The present study found a high level of agreement between the presence of putative periodontal pathogens and positive AST scores at periodontal sites that clinically were considered to be potentially disease active. Prospective studies should be performed to confirm the findings.

The effects of gum chewing, four oral hygiene procedures, and two saliva collection techniques, on the output of bacteria into human whole saliva

Six healthy dentate individuals collected a 5-min sample of unstimulated whole saliva (UWS) and dilutions were plated out on blood agar and grown anaerobically for 48 h. The output of bacteria into saliva (counts/min) was calculated as the product of counts/ml and ml/min. The individuals repeated the collections at intervals of up to 7 h after (1) rinsing with water, (2) eating a meal plus tooth brushing, (3) a thorough dental prophylaxis, or (4) tongue brushing and scraping. They also collected saliva at intervals while chewing gum for 20 min, as did 10 individuals who chewed gum for 2 h. The original six individuals also collected UWS under "drooling" (no oral movements) and "spitting" conditions. Six edentulous individuals not wearing their dentures collected UWS before and after a water rinse. With the four oral hygiene procedures, bacterial outputs fell initially and then rose again, but a repeated-measures ANOVA revealed no significant differences in the effects of the four procedures. Gum chewing caused initial marked increases in the outputs of bacterial and epithelial cells, but these fell with time and reached a plateau after about 10 min at outputs above those in UWS. Samples collected by spitting contained up to 14 times more bacteria than those collected by drooling. Bacterial output by edentulous individuals did not differ from that in those with teeth. It is concluded that bacteria from the teeth and gingival crevices normally make only a small contribution to those in saliva, that various oral hygiene procedures have similar effects on bacterial output into saliva, and that saliva collection conditions should be standardized and specified.

Caries risk assessment from dental plaque and salivary Streptococcus mutans counts on two culture media

This study attempted to determine which combination of plaque or saliva, and tryptic soy agar, bacitracin (TSY20B) or mitis salivarius, bacitracin media, yielded the highest caries-predictive values for mutans counts in children with different caries prevalence. Sixty children were divided into three equally sized groups: caries free, low caries and high caries. Eighteen months later, their caries incidence and initial mutans count were compared. Fissure plaque on TSY20B yielded a high correlation between mutans counts and caries prevalence (P<0.009, r=3346) and incidence (P<0.003, r=4521). The caries-predictive values obtained demonstrate that the coefficient of variation of mutans counts from lower first-molar fissure plaque on TSY20B accounts for 20.4% of the variation in final caries index. This strong correlation provides a valuable tool for the identification of caries-prone individuals.

The clinical and microbiological effects of systemic ornidazole in sites with and without subgingival debridement in early-onset periodontitis patients

BACKGROUND

The purpose of this study was to evaluate the clinical and microbiological effects of systemic ornidazole (ORN) in sites with or without subgingival debridement in early-onset periodontitis (EOP) patients.

METHODS

Two pooled bacterial samples consisting of 4 sites each (scaled and non-scaled sites) were obtained from 30 individuals exhibiting EOP. All patients received oral hygiene instruction (OHI), supragingival scaling and ORN. Subgingival scaling and root planing (SRP) was carried out only in scaled sites. Bacterial samples were taken at baseline (BL) and 1 week and 2, 6, and 12 months after systemic ornidazole administration (500 mg/bid for 7 days). One more sample was taken at scaled sites, one week after SRP.

RESULTS

One week following SRP (scaled sites) Gram-negative facultative and anaerobic rods were significantly reduced while Gram-positive facultative cocci were significantly increased. After ORN administration, P. gingivalis, P. denticola, P. intermedia, B. forsythus, C. rectus, and S. sputigena were no longer detectable in either scaled or non-scaled sites. A statistically significant long-term (2, 6, and 12 months) reduction of P. gingivalis, P. intermedia, P. loescheii, B. forsythus, and C. rectus and a pronounced increase of S. milleri, S. oralis, and S. sanguis counts in both scaled and non-scaled sites were detected in comparison to baseline. A sustained reduction of bleeding tendency and of probing depth was also observed in both scaled and non-scaled sites.

CONCLUSIONS

ORN combined with SRP effects beneficial shifts in the bacterial population associated with substantial clinical improvement, thereby indicating that ORN is effective adjunct in the treatment of EOP deep periodontal pockets where anaerobic bacteria are predominant.

The science and practice of caries prevention

BACKGROUND AND OVERVIEW

Dental caries is a bacterially based disease. When it progresses, acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the carbonated hydroxyapatite mineral--a process called demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors--which include salivary calcium, phosphate and proteins, salivary flow, fluoride in saliva, and antibacterial components or agents--can balance, prevent or reverse dental caries.

CONCLUSIONS

Caries progression or reversal is determined by the balance between protective and pathological factors. Fluoride, the key agent in battling caries, works primarily via topical mechanisms: inhibition of demineralization, enhancement of remineralization and inhibition of bacterial enzymes.

CLINICAL IMPLICATIONS

Fluoride in drinking water and in fluoride-containing products reduces caries via these topical mechanisms. Antibacterial therapy must be used to combat a high bacterial challenge. For practical caries management and prevention or reversal of dental caries, the sum of the preventive factors must outweigh the pathological factors.

Profile of subgingival microbiota in children with mixed dentition

A diversity of microbial species has been detected in children's oral flora at an early age. To investigate the composition of the subgingival microbiota of different groups of teeth in children with mixed dentition, 40 systemically healthy children, aged 7-8 years, randomly chosen, were examined. Subgingival plaque samples were taken from the mesiobuccal sites of 21, 41, 16 and 36 permanent teeth and 53, 73, 64 and 84 deciduous teeth. The samples were cultured for bacterial isolation anaerobically and in 10% CO2 plus air using selective and nonselective media. Forty-five different microbial species were isolated from both permanent and deciduous teeth. Streptococcus sanguis (79-70%), Streptococcus mitis (66-65%), Prevotella melaninogenica (51-57%), Eikenella corrodens (51-52%), Capnocytophaga gingivalis (46-34%), Capnocytophaga ochracea (45-45%), Actinomyces naeslundii (39-60%) and Prevotella intermedia (42-35%) were among the most frequently detected species in permanent and deciduous teeth respectively. Several suspected periodontal pathogens, such as Porphyromonas gingivalis, Prevotella loescheii, Campylobacter gracilis, Bacteroides forsythus, Campylobacter concisus, Peptostreptococcus micros and Selenomonas sputigena, albeit less frequently detected, were present in the microbiota of these children. The bacterial species Streptococcus constellatus, Peptostreptococcus micros, Pseudoramibacter alactolyticus, E. corrodens and Fusobacterium nucleatum were associated with non-bleeding permanent and deciduous teeth whereas Streptococcus intermedius, C. concisus, P. intermedia and P. loescheii were associated with bleeding.

Effects of 0.12% chlorhexidine gluconate on experimental gingivitis in non-human primates: clinical and microbiological alterations

OBJECTIVE

This study examined the efficacy of 0.12% chlorhexidine gluconate (Peridex) to reduce gingival inflammation in the absence of mechanical hygiene and its effect on the oral microbial ecology in a non-human primate (NhP) model of gingivitis.

DESIGN

Twelve NhP were stratified based on existing inflammation into two groups of six NhP per group. Oral hygiene was performed on both groups so as to reach a level of gingival health (BOP < or = 0.3) at the conclusion of the hygiene phase. One group received 30 ml of 0.12% chlorhexidine gluconate twice daily 7 days/week, and a second group received 30 ml of placebo (distilled water colored to match the active) using the same regimen for 10 weeks. MEASUREMENT OUTCOMES: Clinical parameters including plaque (PLI), pocket depth (PD), attachment level (AL), and bleeding on probing (BOP) were evaluated at 2-week intervals. Subgingival plaque samples were collected by paper point at 2-week intervals and cultured for predominant cultivable bacteria.

RESULTS

By week 2, there was a difference in BOP between the groups, which reached statistical significance by week 4. This difference in BOP was maintained throughout the course of the study. Chlorhexidine gluconate (0.12%) had no significant effect on PLI, PD, or AL; although PD was greater in the placebo group after week 2 and throughout the study. Microbiologically, at week 4, the treatment group had a reduction in total bacterial counts, as well as Gram positive bacteria, and total black pigmented bacteria, compared to the placebo group. However, only the differences in Actinomyces spp. reached significance. Interestingly, when both groups received only one treatment/day on the weekends (i.e., day 6 and 7), an associated loss of statistically significant differences between the two groups was observed. Additional experiments dosing the non-human primates once daily, 5 days/week yielded no significant differences in clinical parameters, including bleeding, when compared with the placebo group.

CONCLUSION

Non-human primates provided a model system of gingivitis for testing antimicrobial agent effects on the subgingival ecology and accompanying inflammatory responses. Chlorhexidine gluconate (0.12%), even in the absence of mechanical hygiene, was effective in inhibiting clinical signs of inflammation, associated with alterations in the subgingival microbial ecology, most notably Actinomyces spp.

Sampling of periodontal pathogens by paper points: evaluation of basic parameters

Paper points are widely established for the collection of subgingival plaque or other oral samples to analyze the microbiota, especially the presence of periodontal pathogenic bacteria such as Actinobacillus actinomycetemcomitans or Porphyromonas gingivalis. In contrast to the high frequency of usage of paper points in oral sampling, very few data are available about the parameters influencing the sampling process. Therefore, in four different in vitro experiments (6-9 repeats), we inoculated paper points with standardized suspensions (2 x 10(9) colony-forming units/ml) of A. actinomycetemcomitans and P. gingivalis to test the influence of the origin (kind) of paper point ("manufacturer"), size (according to the International Organization for Standardization ISO 25-80), sampling time (5 to 60 s), and elution time (5 to 60 s). Sampled bacteria were detected and (semi-) quantified using 16S rRNA/DNA-directed oligonucleotide probes. The bacterial load was categorized and calculations performed with index values ranging between 0 (below the detection limit of 10(2) to 10(3) colony-forming units) and 9 (> 10(6) colony-forming units). We found statistically significant differences in the efficiency of bacterial sampling between the 5 paper point manufacturers tested, expressed in a mean bacterial index between 4.4 and 7.8. ISO 45 Paper points were statistically proven to work most efficiently. According to our results, a sampling time of 60 s seems to be optimum. However, shorter times between 5 and 30 s did not significantly reduce the sampling efficiency. We found an interval of 20 s best to elute bacteria from the paper points by vortexing. The evaluation of basic parameters for subgingival plaque sampling by paper points might help to optimize microbiologically based diagnostics in periodontal diseases.

Simultaneous detection of Bacteroides forsythus and Prevotella intermedia by 16S rRNA gene-directed multiplex PCR

In a 16S rRNA gene-directed multiplex PCR, Prevotella intermedia- and Bacteroides forsythus-specific reverse primers were combined with a single conserved forward primer. A 660-bp fragment and an 840-bp fragment that were specific for both species could be amplified simultaneously. A total of 152 clinical samples, subgingival plaque and swabs of three different oral mucosae, from 38 periodontitis patients were used for the evaluation.

Prevention and reversal of dental caries: role of low level fluoride

Dental caries is a bacterially based disease that progresses when acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the mineral, that is, demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors which include salivary calcium, phosphate and proteins, salivary flow, and fluoride in saliva can balance, prevent or reverse dental caries. Fluoride works primarily via topical mechanisms which include (1) inhibition of demineralization at the crystal surfaces inside the tooth, (2) enhancement of remineralization at the crystal surfaces (the resulting remineralized layer is very resistant to acid attack), and (3) inhibition of bacterial enzymes. Fluoride in drinking water and in fluoride-containing products reduces tooth decay via these mechanisms. Low but slightly elevated levels of fluoride in saliva and plaque provided from these sources help prevent and reverse caries by inhibiting demineralization and enhancing remineralization. The level of fluoride incorporated into dental mineral by systemic ingestion is insufficient to play a significant role in caries prevention. The effect of systemically ingested fluoride on caries is minimal. Fluoride "supplements" can be best used as a topical delivery system by sucking or chewing tablets or lozenges prior to ingestion.

Clinical and microbiological characteristics of smokers with early onset periodontitis

Cigarette smoking is a potential risk factor which has recently been associated with periodontal disease progression. The objective of this study was to compare the microbial profile of smokers and non-smokers in a group of patients with early onset periodontitis. The study population consisted of 60 healthy individuals, 40 males and 20 females aged 22 to 35 yr, exhibiting early onset periodontitis. Thirty patients were smokers (30.9 cigarettes/d) and 30 non-smokers. Smokers had a higher proportion of deep pockets (PD >5 mm), especially in the maxilla anterior and premolar regions (p < 0.001) and presented a significantly greater mean probing depth and attachment loss (p <0.05) in diseased sites and a significantly greater alveolar bone loss (p <0.01) compared to non-smokers. Two pooled bacterial samples were obtained from each patient. Samples were collected from the deepest periodontal pockets of each quadrant. The samples were cultured anaerobically and in 10% CO2 plus air for bacterial isolation using selective and non-selective media. Isolates were characterized to species level by conventional biochemical tests and various identification kits. Smokers harboured a greater number of bacteria in total. Analysis of bacterial counts using the ANOVA (Mann-Whitney U-test) showed that Staphylococcus aureus, Peptostreptococcus micros, Campylobacter concisus, Escherichia coli, Bacteroides forsythus, C. gracilis, C. rectus, Porphyromonas gingivalis, Selenomonas sputigena, Candida albicans and Aspergillus fumigatus were found in significantly higher numbers and more frequently in smokers while Streptococcus intermedius, A. naeslundii, A. israelii and Eubacterium lentum were detected more frequently and in significantly higher proportions in non-smokers. The isolation of bacteria belonging to the exogenous flora such as E. coli, C. albicans, A. fumigatus and S. aureus in smokers' microbiota underscores the importance of the host that is adversely affected by cigarette smoking.

Epithelial cell invasion by Actinobacillus actinomycetemcomitans strains from restriction fragment-length polymorphism groups associated with juvenile periodontitis or carrier status

The epithelial cell invasiveness of Actinobacillus actinomycetemcomitans strains of different restriction fragment-length polymorphism (RFLP) groups associated with disease conversion and asymptomatic carrier status in localized juvenile periodontitis was examined. Twenty clinical isolates were studied for their ability to invade KB monolayers, using the quantitative gentamicin killing assay. Five isolates were found to be invasive, five were not invasive; and the other 10 did not invade better than an invasion negative control Haemophilus aphrophilus strain ATCC 19415. Using probe-specific DNA fingerprinting. 11 strains were assigned to RFLP group II (disease-associated); 4 to RFLP type XIII (carrier status associated); and the other to groups III, IV, V and VII. Eight isolates, all RFLP group II, were leukotoxin producers as determined by PCR amplification of the lkt promoter region. No correlation was found between invasiveness and RFLP group. Leukotoxin production was more associated with noninvasive than invasive strains.

Subgingival microflora associated with nifedipine-induced gingival overgrowth

The purpose of this study was to examine the composition of subgingival plaque of 140 periodontal lesions in 35 patients with cardiovascular disorders who were administered nifedipine and manifested nifedipine-induced gingival overgrowth (GO). Age was inversely associated with the GO. Plaque index and bleeding index showed a significant association with GO, while nifedipine dosage and duration of nifedipine therapy were not found to be significant predictors of GO. The gingival inflammation as expressed in the logistic regression model by the interaction term color x tone was found to be significantly associated with the GO. Statistically significant differences between the groups of comparable probing depth and different degrees of GO were detected for Propionibacterium acnes, Capnocytophaga gingivalis, Capnocytophaga ochracea, Capnocytophaga sputigena, Bacteroides gracilis, Fusobacterium mortiferum, Fusobacterium nucleatum, Fusobacterium varium and Selenomonas sputigena in deep and enlarged lesions. Significantly more frequently isolated were the bacterial species Eubacterium alactolyticum, Campylobacter concisus, C. gingivalis, C. ochracea, C. sputigena, F. mortiferum, F. nucleatum, and F. varium from the more enlarged lesions (GO >3).

Influence of smoking on the outcome of periodontal surgery. A 5-year follow-up

The 5-year outcome following periodontal surgery was evaluated in 57 patients that had received regular maintenance care throughout the follow-up period. The study population included 20 smokers, 20 former smokers and 17 non-smokers in the age range 37-77 years. The clinical characteristics evaluated were supragingival plaque, gingival bleeding and pocket probing depth. The region assigned for surgery was, in addition, radiographically evaluated in terms of periodontal bone height. Furthermore, the occurrence of the periopathogens Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Prevotella intermedia (Pi) and the gingival crevicular fluid (GCF) levels of tumor necrosis factor alpha (TNF-alpha) were assessed at follow-up. Plaque index was 28.5% at baseline and 32.9% at follow-up, indicating a good standard of oral hygiene, and gingival bleeding 31.7% and 24.9%, respectively, suggesting a low to moderate level of gingival inflammation. In regions assigned for surgery, pocket probing depth decreased significantly from on average 5.6 mm to 4.3 mm (p<0.0001) and periodontal bone height increased significantly from on average 62.5% to 67.5% (p<0.0001). In terms of bone height, the outcome was less favorable among smokers compared with non-smokers. There was a predominance of smokers among patients exhibiting loss of bone height after the 5 years of maintenance. No significant associations were found between the therapeutical outcome and supragingival plaque or subgingival occurrence of periopathogens. The associations between GCF levels of TNF-alpha and probing depth and bone height were unclear, whereas the level of TNF-alpha was significantly elevated in smokers.