Untreated Chronic Periodontitis Research Articles

Functional foods/ingredients and periodontal diseases

Periodontal diseases are a collection of inflammatory processes that affect the periodontium, that is, the teeth supporting tissues. Gingivitis (infected red swollen and easily bleeding gums) is a mild reversible form of periodontal disease. Almost 100% of the population suffers from time to time from gingivitis. Gingivitis can develop into periodontitis, which is a chronic inflammatory disease of the supporting tissues of the teeth [34]. In conjunction with red, swollen gums that easily bleed as a result of the disease, teeth may show exposed root surfaces and often dental radiographs reveal periodontal (alveolar) bone loss around the teeth due to the inflammation process; teeth will become mobile and migrate and will eventually exfoliate. Patients with periodontitis may have bad breath, suffer from important subjective and objective esthetic problems and experience problems with chewing due to tooth mobility and loss of teeth. Dental professionals provide labor-intensive treatment to periodontitis patients, including periodontal surgery. Like gingivitis, also periodontitis has a relative high prevalence in the population. About 10% of the total adult population and about 30% of individuals over the age of 50 years have been estimated to suffer from severe periodontitis [9]. Chronic, adult form of periodontitis progresses at a relative slow rate and is diagnosed during middle age. However, in some individuals, the disease manifests itself at adolescent or post-adolescent age in a rapidly progressive manner, and this form of disease is diagnosed as early onset periodontitis or aggressive periodontitis [42]. Periodontitis may be considered as a model for the other inflammatory diseases, with a pathogenesis that is multifactorial, involving complex interactions between multiple genetic traits, infectious agents and lifestyle factors such as diet and smoking. Several lines of data suggest that periodontitis may be associated with systemic diseases. For example, periodontitis has been associated with increased risk for cardiovascular diseases (for a recent review see [46]), possibly through the elevation of the acute-phase reactant C-reactive protein or other systemic markers of inflammation [24]. Oral bacteria may play an important role in the systemic reactions to periodontitis. There are strong indications that the inflamed and ulcerated subgingival pocket epithelium forms an easy port of entry for oral bacteria. Short moments of bacteremia occur most likely several times a day. Like any other inflammatory condition, untreated chronic periodontitis may pose a risk for the overall health of the subject [23]. The etiology of periodontitis is multifactorial, involving the following.

Immune Responses to HSP65/60 in Periodontal Disease

Chronic periodontitis (CP) is a chronic inflammatory condition which destroys the supporting tissues of teeth and increases in prevalence with age. Immune responses against heat shock proteins (HSP) can be cross-reactive among bacterial and human antigens. There is evidence that microbial HSP65 and human HSP60 are involved in periodontal disease. The aim of this study is to investigate immune responses to the human HSP60 and microbial HSP65 in patients with CP and relate these to the level of inflammation and smoking status. We collected serum samples from 30 patients with chronic gingivitis (CG) and 30 patients with CP. In each group, eight subjects were current smokers. ELISA was used to determine the levels of serum anti-HSP and C-reactive protein (CRP) in each group. Peripheral blood mononuclear cells were also isolated and stimulated with HSPs. Significant lymphoproliferation was seen in CP when stimulated with human HSP60. CRP and serum anti-human HSP60 IgG were elevated in CP compared to the CG, but not serum anti-microbial HSP 65 IgG. In view of the potential confounding effects of smoking in CP, a group of current smokers (n = 16) was also recruited to investigate whether smoking affects HSP immune responses. There was no significant difference in HSP-induced lymphoproliferation between smokers and non-smokers in either the CG or CP. There was a significant correlation between CRP and lymphoproliferative responses to Human HSP60 irrespective of smoking status. This study shows that serum anti-human HSP60 IgG and serum CRP are raised in untreated CP. In CP, serum CRP levels correlated significantly with human HSP60-induced lymphoproliferation, but not with anti-HSP antibody levels.

Increased systemic elastase and C-reactive protein in aggressive periodontitis (CLOI-D-00160R2)

The inflammatory mediators, serum elastase and C-reactive protein (CRP), are associated with an increased risk for coronary heart disease. Thus, the aim of this study is to compare systemic inflammatory mediators in periodontally healthy controls (C), patients with untreated aggressive (AgP) and chronic (ChP) periodontitis. C [periodontal pocket probing depth (PPD) <3.6 or <5 mm without bleeding (BOP), BOP < 10%], ChP (PDD ≥ 3.6 mm and probing attachment loss ≥5 mm at >30% of sites; age >35 years), and AgP (clinically healthy; PDD ≥ 3.6 mm at >30% of sites, bone loss ≥50% at ≥2 teeth; age ≤35 years) were examined clinically, and the body mass index was assessed. Blood was sampled for assessment of serum levels of elastase, CRP, lipopolysaccharide binding protein (LBP), interleukin (IL) 6, 8, and leukocyte counts. Thirty C, 31 ChP, and 29 AgP were analyzed. Elastase, CRP, LBP, and IL-6 levels were elevated in AgP compared to C (p < 0.013), whereas leukocyte counts and IL-8 were similar. Multiple regression analysis identified AgP (p < 0.001) and education level (p < 0.001) to explain 47% of the variation of elastase. AgP (p = 0.003), African origin (p = 0.006), female sex (p = 0.002), and BMI (p < 0.001) explained 39% of the variation of CRP. Serum elastase and CRP are significantly elevated in AgP compared to C. AgP patients exhibit a stronger systemic inflammatory burden than C patients.

Levels of Interleukin‐21 in Patients With Untreated Chronic Periodontitis

A growing body of evidence suggested that interleukin (IL)-21 enhances the effector phase during T-cell responses. The aim of our study is to determine the levels of IL-21 in periodontal sites from patients with chronic periodontitis and controls. The population studied consisted of 34 patients (15 with chronic periodontitis and 19 healthy patients). Twenty samples (10 gingival crevicular fluid [GCF] and 10 gingival biopsies) were collected from each group before the patients with periodontitis received periodontal treatment. Total protein concentrations were measured in all samples; the presence of IL-21 was confirmed by immunohistochemistry and Western blot, and IL-21 levels were quantified through an enzyme-linked immunosorbent assay. Statistical analyses were performed using statistical software. Data were expressed as patient means ± SDs or medians (interquartile ranges) by using the χ(2), Student t, and Mann-Whitney U tests. GCF IL-21 was mainly detected in patients with chronic periodontitis (P <0.05). Levels of IL-21 in gingival tissues were significantly higher in patients with chronic periodontitis compared to healthy individuals (P <0.05). The Western blot and immunohistochemical staining confirmed the presence of IL-21 in periodontal tissues and GCF. IL-21 was highly expressed in patients with chronic periodontitis, especially in gingival biopsies; therefore, IL-21 might play a role in the T-cell response.

Sub-antimicrobial doxycycline for periodontitis reduces hemoglobin A1c in subjects with type 2 diabetes: A pilot study

In vitro and animal studies suggest a possible role for the tetracycline class of drugs in the inhibition of non-enzymatic protein glycation. We conducted a 3-month, randomized placebo-controlled pilot clinical trial of conventional sub-gingival debridement (periodontal therapy), combined with either a three month regimen of sub-antimicrobial-dose doxycycline (SDD), a two week regimen of antimicrobial-dose doxycycline (ADD), or placebo in 45 patients with long-standing type 2 diabetes (mean duration 9 years) and untreated chronic periodontitis. Subjects were taking stable doses of oral hypoglycemic medications and/or insulin. Treatment response was assessed by measuring hemoglobin A1c (HbA1c), plasma glucose, and clinical periodontal disease measures. At one-month and three-month follow-up, clinical measures of periodontitis were decreased in all groups (data to be presented elsewhere). At three months, mean HbA1c levels in the SDD group were reduced 0.9% units from 7.2% units±2.2 (±SD), to 6.3% units±1.1, which represents a 12.5% improvement. In contrast, there was no significant change in HbA1c in the ADD (7.5%±2.0 to 7.8%±2.1) or placebo (8.5%±2.0 to 8.5%±2.6) groups. Mean HbA1c change from baseline was significantly greater in the SDD group compared with the ADD group (p=0.04) but not placebo (p=0.22). Moreover, a larger proportion of subjects in the SDD group experienced improvement (p<0.05) compared to the ADD or placebo groups. Mean plasma glucose levels were not significantly different between or within the groups. The results of this pilot study suggest that the treatment of periodontitis with sub-gingival debridement and 3-months of daily sub-antimicrobial-dose doxycycline may decrease HbA1c in patients with type 2 diabetes taking normally prescribed hypoglycemic agents.

The effect of smoking on the mRNA expression of MMPs and TIMP-1 in untreated chronic periodontitis patients: a cross-sectional study

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important for extracellular matrix. Expression of MMPs has been evaluated in gingiva without studying smoking. The aim of this study was to explore the effect of smoking on mRNA expression of MMP-1, -3, -8, -9 and -13 and TIMP-1 in untreated chronic periodontitis and in periodontal health. Gingival samples were harvested from 30 subjects with untreated chronic periodontitis (15 nonsmokers and 15 smokers) and 30 periodontally healthy subjects (15 nonsmokers and 15 smokers). Full-mouth plaque score, gingival index, bleeding on probing, probing depth and clinical attachment level were recorded. Total RNA was isolated, and the mRNA expression of MMPs and TIMP-1 was assessed by RT-PCR. Periodontitis groups were comparable in clinical measurements. Nonsmoker subjects with periodontitis had statistically significantly higher MMP-1, lower MMP-9 and TIMP-1 expression and higher MMP-1/TIMP-1 ratio than smokers; and higher MMP-8 expression and MMP-8/TIMP-1 and MMP-1/TIMP-1 ratios than healthy nonsmokers. Healthy nonsmokers had statistically significantly higher MMP-13 expression than healthy smokers. Smoker periodontitis and healthy subjects had similar expression levels of MMPs and TIMP-1 and MMPs/TIMP-1 ratios. There was correlation among the MMPs only for smoker periodontitis subjects. Expression of MMP-13 was correlated with mean clinical attachment level. Within its limits, this study demonstrated that smoking affected mRNA expression of MMPs and TIMP-1, MMPs/TIMP-1 ratios and relationships among MMPs in untreated chronic periodontitis and expression of MMPs in health. In the absence of smoking, chronic periodontitis affected expression of MMPs and MMPs/TIMP-1 ratios.

Interleukin-17 and interleukin-18 levels in saliva and plasma of patients with chronic periodontitis

This study was planned to investigate whether patients with chronic periodontitis exhibit different salivary and/or plasma concentrations of interleukin (IL)-17 and IL-18 compared with clinically healthy subjects. Whole saliva and blood samples, together with full-mouth clinical periodontal recordings, were obtained from 22 otherwise healthy untreated nonsmokers with chronic periodontitis and from 21 systemically and periodontally healthy control subjects. The concentrations of IL-17 and IL-18 in saliva and plasma were determined using ELISAs. The healthy control group exhibited significantly lower values in all clinical periodontal measurements (p < 0.001). The salivary concentration of IL-17 was significantly lower, and that of IL-18 significantly higher, in patients from the chronic periodontitis group compared with healthy control subjects (p = 0.025 and p = 0.009, respectively). Plasma IL-17 and IL-18 concentrations were similar in the two study groups (p > 0.05). Within the limits of the present study, it may be suggested that an elevated salivary IL-18 level in untreated nonsmoker chronic periodontitis patients has the potential to be a biomarker for periodontal tissue destruction.

Expression of cytokines in the gingival crevicular fluid and serum from patients with inflammatory bowel disease and untreated chronic periodontitis

Previous studies have reported an increased prevalence/severity of chronic periodontitis in patients with inflammatory bowel disease. However, the pathogenesis of periodontal lesions in such patients has not been characterized. The aim of this pilot study was to characterize the pattern of expression of cytokines in the gingival crevicular fluid and serum from patients with untreated chronic periodontitis and Crohn's disease, ulcerative colitis and systemically healthy controls. Fifteen patients with Crohn's disease, 15 patients with ulcerative colitis and 15 controls participated in the study. All subjects had been diagnosed with untreated chronic periodontitis. The clinical parameters evaluated were clinical attachment loss, bleeding on probing and percentage of plaque. The gingival crevicular fluid was sampled from four shallow and four deep periodontal sites of each patient. The concentrations of the cytokines interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, interferon-γ and tumor necrosis factor-α were measured using a commercially available Lincoplex kit and the concentration of IL-18 was measured using an ELISA. Multiple comparisons analysis showed that clinical attachment loss, bleeding on probing, percentage of plaque and volume of gingival crevicular fluid were similar across the groups. The concentration of IL-4 in the gingival crevicular fluid differed significantly between groups in shallow sites (p = 0.046), with higher values found for the controls. In serum, the concentration of IL-18 was also significantly different between groups, with lower values found for controls (p = 0.018). This study showed a higher concentration of IL-18 in serum, but not in the gingival crevicular fluid, from periodontitis patients with Crohn's disease or ulcerative colitis compared with controls. The expression of cytokines was similar in the gingival crevicular fluid from patients with untreated chronic periodontitis who also had Crohn's disease or ulcerative colitis and in systemically healthy controls with untreated chronic periodontitis.

Combined photodynamic and low-level laser therapies as an adjunct to nonsurgical treatment of chronic periodontitis

In recent years, there has been a growing interest in the use of dental lasers for treatment of periodontal diseases. The purpose of this short-term clinical trial was to evaluate the effects of a combination of photodynamic therapy with low-level laser therapy as an adjunct to nonsurgical treatment of chronic periodontitis. Twenty-four nonsmoking adults with untreated chronic periodontitis were randomly assigned in a split-mouth design to receive scaling and root debridement with or without one course of adjunctive photodynamic therapy and low-level laser therapy within 5 d. Plaque, bleeding on probing, probing depth and gingival recession were recorded at baseline, 1 and 3 mo after the treatment. Gingival crevicular fluid was collected for assay of interleukin-1β levels at baseline, 1 wk and 1 mo. The test teeth achieved greater reductions in the percentage of sites with bleeding on probing and in mean probing depth at 1 mo compared with the control teeth (p < 0.05). A significant decrease in gingival crevicular fluid volume was observed in both groups at 1 wk (p < 0.001), with a further decrease at 1 mo in the test sites (p < 0.05). The test sites showed a greater reduction of interleukin-1β levels in gingival crevicular fluid at 1 wk than the control sites (p < 0.05). No significant differences in periodontal parameters were found between the test and control teeth at 3 mo. The present study suggests that a combined course of photodynamic therapy with low-level laser therapy could be a beneficial adjunct to nonsurgical treatment of chronic periodontitis on a short-term basis. Further studies are required to assess the long-term effectiveness of the combination of photodynamic therapy with low-level laser therapy as an adjunct in nonsurgical treatment of periodontitis.

Screening for subgingival occurrence of gram-negative enteric rods in periodontally diseased and healthy subjects

Objective This study aimed to determine whether the variations in the occurrence of gram-negative enteric rods as detected through a longitudinal follow up with three consecutive visits, may be associated with the periodontal clinical status. Design Clinical and demographic parameters from 63 untreated chronic periodontitis (CP) subjects and 45 healthy controls (HC) were analyzed. Subgingival plaque samples were obtained from 6 sites in each subject at baseline, 1-week, and 1-month visits and processed using culture and biochemical tests. Culture findings were categorized taking into account the detection frequency of gram-negative enteric rods as persistent presence, transient presence, or absence of enteric rods in any sampling time. Results Although transient presence of gram-negative enteric rods was more prevalent in CP subjects (16.7%) than HC subjects (9.3%), the difference was not significant ( P > 0.05). The majority of subjects showed a transient presence of gram-negative enteric rods at concentrations <2 × 10 2 CFU/mL. Persistent presence of gram-negative enteric rods was not observed in any subject through the entire study period. Moreover, differences in both the detection frequencies of individual species and the total number of gram-negative enteric rods were not statistically significant neither inter- nor intragroups. Conclusion The findings of the present study could indicate that gram-negative enteric rods are merely transient microorganisms within the subgingival environment and suggest that the periodontal clinical status appeared not to be influenced by the presence of these species.

Detection of selected bacterial species in intraoral sites of patients with chronic periodontitis using multiplex polymerase chain reaction

ObjectiveThe aim of this study was to detect the prevalence of selected bacterial species in intraoral sites of patients with chronic periodontitis (CP) using multiplex polymerase chain reaction (PCR).MethodologySamples were collected from the tongue dorsum, buccal mucosa, supragingival and subgingival plaque and saliva of 30 patients with untreated CP. Multiplex PCR was used to determine prevalence rates, which were then compared using a chi-square test. Significance level was set at p<0.05. Mean and standard deviation values were used to evaluate variations in prevalence according to site.ResultsThe prevalence of S. mutans was 70% in saliva; 60% in samples collected from the tongue dorsum; 50% in samples collected from the buccal mucosa; 56.5% in the supragingival plaque; and 53.5% in the subgingival plaque. The prevalence of E. faecalis ranged from 3.5% to 13.5% in all intraoral microenvironment. The highest prevalence of P. gingivalis was found in subgingival plaque (53.5%), and of P. intermedia in supragingival plaque (33.5%), subgingival plaque (30%) and tongue dorsum (33.5%). The prevalence of bacteria did not vary significantly among the intraoral sites.ConclusionsAll studied bacteria were identified in intraoral sites. S. mutans, P. gingivalis and P. intermedia had high prevalence rates, but the prevalence of E. faecalis was low. Multiplex PCR proved to be an adequate method for epidemiological studies.

Quantification of periodontal pathogens by paper point sampling from the coronal and apical aspect of periodontal lesions by real-time PCR

The present study compared the recovery of six periodontal pathogens by paper point samples from two different aspects of periodontal lesions by quantitative real-time polymerase chain reaction (PCR). Twenty patients with untreated chronic periodontitis were randomized into two groups. Before subgingival instrumentation and after 10 weeks samples in group A were taken first with a paper point half length (HP) of the probing depth, then with a paper point full length (FP) at the same site. In group B sampling sequence was reversed. Analysis by real-time PCR enabled quantification of six bacteria as well as total bacterial count (TBC). Statistical analysis included t test, Kappa, and Spearman's correlations. Higher TBC could be harvested by use of FP than by HP (mean of differences of ln-transformed counts before therapy: -0.791, CI [-1.515, -0.068], SD 0.770, p = 0.034; after therapy: -0.563, CI [-1.151, 0.024], SD 0.625, p = 0.059). The plaque composition regarding total target pathogens was similar for both samples. Both, for TBC as well as for single target bacteria a strong positive correlation was found between HP and FP (Kappa, Spearman correlation: Aggregatibacter actinomycetemcomitans 0.807, 0.778; Fusobacterium nucleatum 0.573, 0.772; Porphyromonas gingivalis 0.733, 0.824; Prevotella intermedia 0.480, 0.756; Treponema denticola 0.807, 0.814; and Tannerella forsythia 0.692, 0.695). The recovery of target pathogens was similar following sampling at various depths of the periodontal lesion.

Increased expression of extracellular matrix metalloproteinase inducer is associated with matrix metalloproteinase‐1 and ‐2 in gingival tissues from patients with periodontitis

Extracellular matrix metalloproteinase inducer (EMMPRIN), an immunoglobulin-like cell surface glycoprotein, could promote collagenolytic balance in favor of the expression and activation of matrix metalloproteinases (MMPs). This study was to investigate the expression of EMMPRIN in gingival tissues from different periodontal conditions and to correlate it with the production of MMP-1 and MMP-2. Gingival biopsies were collected from 15 patients with untreated advanced chronic periodontitis and 15 patients with aggressive periodontitis (AgP). The control group consisted of 12 subjects diagnosed either as periodontally healthy individuals or as individuals with a gingival index of one (H/G1). The peptides and mRNA of EMMPRIN, MMP-1 and MMP-2 were detected by immunohistochemistry and semi-quantitative reverse transcriptase-polymerase chain reaction, respectively. The expression of EMMPRIN, MMP-1 and MMP-2 peptides in periodontally healthy tissues was mainly confined to the gingival epithelium. The EMMPRIN was strongly expressed in the cell membrane of the basal layer. Immunoreactivity for EMMPRIN was more intensive and more widespread in periodontitis, extended from the epithelial layers to the underlying connective tissues, and was essential in both inflammatory and fibroblast-like cells. In addition, MMP-1 and MMP-2 showed the same localized expression. The chronic periodontitis group had a significantly higher mRNA expression of EMMPRIN and MMP-2 compared with the H/G1 subjects (p < 0.05). Production of MMP-1 and MMP-2 by gingival tissues was correlated with the mRNA level of EMMPRIN (r = 0.463, p = 0.013 for MMP-1 and r = 0.404, p = 0.033 for MMP-2). The expression of EMMPRIN in human normal and diseased gingiva might contribute to periodontal physiological and pathological processes; moreover, its increased production might be associated with MMP-1 and MMP-2 expression.

Short‐term clinical effects of adjunctive antimicrobial photodynamic therapy in periodontal treatment: a randomized clinical trial

The aim of this study was to assess the effect of adjunctive antimicrobial photodynamic therapy (aPDT) in chronic periodontitis. Twenty patients with untreated chronic periodontitis were included. All teeth received periodontal treatment comprising scaling and root planing. Using a split-mouth design, two quadrants (test group) were additionally treated with aPDT. Sulcus fluid flow rate (SFFR) and bleeding on probing (BOP) were assessed at baseline, 1 week and 3 months after treatment. Relative attachment level (RAL), probing depths (PDs) and gingival recession (GR) were evaluated at baseline and 3 months after treatment. Baseline median values for PD, GR and RAL were not different in the test group and control group. Values for RAL, PD, SFFR and BOP decreased significantly 3 months after treatment in the control group (median delta RAL: -0.35 mm, inter-quartile range: 0.21 mm), with a higher impact on the sites treated with adjunctive aPDT (median delta RAL: -0.67 mm, inter-quartile range: 0.36 mm, p<0.05). GR increased 3 months after treatment with and without adjunctive aPDT (p<0.05), with no difference between the groups (p>0.05). In patients with chronic periodontitis, clinical outcomes of conventional subgingival debridement can be improved by adjunctive aPDT.

Saliva concentrations of RANKL and osteoprotegerin in smoker versus non‐smoker chronic periodontitis patients

To compare the salivary receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) concentrations in smokers versus non-smokers with chronic periodontitis. Whole saliva samples were obtained from 67 untreated chronic periodontitis patients, of whom 34 were smokers, and from 44 maintenance patients, of whom 22 were smokers. Full-mouth clinical periodontal measurements were recorded. Saliva cotinine, sRANKL and OPG concentrations were determined by ELISA. Statistical analysis was performed using the Mann-Whitney U test, Bonferroni's correction for multiple comparisons and Spearman's correlations. Untreated smokers exhibited significantly higher values of clinical periodontal recordings than untreated non-smokers (all p<0.05). Salivary cotinine level correlated with clinical attachment level (p=0.023). Smoker versus non-smoker maintenance groups showed no significant differences in clinical parameters. There were significant differences in sRANKL and OPG concentrations between untreated and maintenance groups (all p<0.01). Salivary OPG concentration was significantly lower (all p<0.01) and the sRANKL/OPG ratio was higher (all p<0.01) in smokers than in non-smokers. OPG concentration correlated positively with probing depth, clinical attachment level and bleeding on probing (all p<0.005) and negatively with pack-year, and cotinine level (p<0.05). Salivary RANKL and OPG concentrations are suggested to be affected by smoking as not only the untreated but also the treated smokers exhibited higher RANKL and lower OPG concentrations than non-smokers.

Antibiotics as the only therapy of untreated chronic periodontitis: a critical commentary

Antibiotics as the only therapy of untreated chronic periodontitis: a critical commentary

Matrix Metalloproteinase‐13 Is Highly Expressed in Destructive Periodontal Disease Activity

Matrix metalloproteinases (MMPs) participate in extracellular matrix degradation in physiological and pathological conditions. The available evidence suggests that MMP-13 plays a significant role in both the initiation and progress of bone resorption. The aim of our study was to identify the presence of MMP-13 in adult patients with untreated chronic periodontitis. We also determined the activity of MMP-13 present in lesions undergoing episodic attachment loss in gingival crevicular fluid (GCF) samples. After monitoring at 2 and 4 months, 21 patients showed destructive periodontitis (periodontally affected sites presenting at least two sites with > or =2 mm clinical attachment loss), and GCF samples were collected both from active and inactive sites (21 GCF samples, each). GCF was collected during a 30-second interval using a paper strip, and an immunofluorescence assay was performed to determine the basal activity of MMP-13 and the relationship between 4-aminophenylmercuric acetate (APMA)-activated total MMP-13 and basal MMP-13 activity. Gingival tissues from five patients were fixed in formalin and MMP-13 expression was demonstrated using immunohistochemistry and in situ hybridization. MMP-13 molecular forms were examined by Western immunoblotting with monoclonal antibodies. MMP-13 was found in 100% of GCF samples from patients with chronic periodontitis. Active sites, associated with tissue destruction, had significantly higher proportions of active MMP-13 and MMP-13 activity levels than their inactive counterparts (1.49 versus 1.17 ng fluorescent product, respectively; P <0.05). Western blot, immunohistochemical staining, and in situ hybridization confirmed the presence of MMP-13 in periodontal disease, with observable differences between periodontitis and healthy subjects. MMP-13 immunoreactivities were seen mainly as 55 and 48 kDa, corresponding to partially and fully activated forms, respectively, and a smaller proportion of 60-kDa proenzyme form. MMP-13 activity in GCF samples was significantly increased in active sites from progressive periodontal disease, supporting its role in the alveolar bone loss developed in this disease.

Chewing fails to induce oral bacteraemia in patients with periodontal disease

To investigate whether chewing in patients with untreated chronic periodontitis or plaque-induced gingivitis causes bacteraemia of oral origin. Twenty-one patients with untreated chronic periodontitis (32-75 years old) and 20 with plaque-induced gingivitis (26-54 years old) chewed a standard wax medium for 4 min. Blood samples were drawn before, during and 5 min. post-chewing. Aerobic and anaerobic Bactec system culturing was performed for 21 days and positive bottles were subcultured and isolates were identified to genus level. A full periodontal analysis was performed on all teeth and included probing depths, recession, attachment levels, bleeding on probing, mobility plaque index and gingival index. Radiographs were assessed for the severity of alveolar bone loss. No bacteraemia of oral origin was detected in any patient. Skin contaminants (Staphylococcus epidermidis, Propionibacterium spp.) were detected in blood samples from three patients (two periodontitis; one gingivitis). Chewing did not cause bacteraemia in chronic periodontitis or plaque-induced gingivitis patients and may not be a risk factor for infective endocarditis in at-risk individuals with periodontal disease.

Effects of metronidazole plus amoxicillin as the only therapy on the microbiological and clinical parameters of untreated chronic periodontitis

To determine the effect of metronidazole plus amoxicillin (M+A) as the sole therapy, on the subgingival microbiota of chronic periodontitis. Twenty-two patients with untreated chronic periodontitis were randomly assigned to a group that received M+A for 7 days, or to a group receiving scaling and root planing (SRP) and two placebos. Clinical measurements including sites with plaque, bleeding on probing (BOP), probing depth (PD) and attachment level (AL) were made at baseline, 3, 6, 9 and 12 months. Subgingival plaque samples were taken from all teeth at baseline 3, 6, 9 and 12 months for the counts of 40 subgingival species using checkerboard DNA-DNA hybridization. Mean PD was reduced from 2.80+/-0.45 at baseline to 1.95+/-0.05 at 12 months (P<0.001) and from 2.39+/-0.41 to 1.95+/-0.10 (P<0.001) in the M+A- and SRP-treated patients, respectively. Corresponding values for relative mean AL were 10.07+/-1.30-9.77+/-0.34 (P<0.001) and 9.94+/-0.28-9.77+/-0.26 (P<0.001). Percentage of sites exhibiting BOP were 40.6+/-18.3-14.0+/-1.4 (P<0.001), and 38.5+/-5.1-19.0+/-2.8 (P<0.001) in the M+A and SRP groups, respectively. Mean total DNA probe counts and counts of the majority of the 40 test species were significantly reduced over time in both groups, with no significant differences detected at any time point between groups. At 12 months many of the species were still present at significantly lowered levels compared with their baseline counts in both groups. Changes in clinical and microbiological parameters were similar after receiving systemically administered M+A as the sole therapy or after receiving SRP only.

Sampling Strategy for Intraoral Detection of Periodontal Pathogens Before and Following Periodontal Therapy

The aim of this study was to identify a sampling strategy with high probability for detecting oral colonization by Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens, Tannerella forsythensis, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola before and following mechanical periodontal therapy. Samples were taken from the following intraoral sites in 35 patients with untreated chronic periodontitis before and 1.5, 3, and 6 months after non-surgical periodontal therapy: supra- and subgingival plaque from the deepest pockets in each sextant; pooled supra- and subgingival plaque from another six randomly selected, less affected teeth; mucosal swab samples from the tongue, tonsils, throat, and buccal mucosa; and stimulated and unstimulated saliva. Microbial species were identified by polymerase chain reaction (PCR). Of the sampling of all assessed sites, the highest probability for simultaneously detecting the tested pathogens was found in respect to the combination of supra- and subgingival plaque samples taken from the most affected tooth in each sextant in untreated patients (probability: 83% to 95% for the assessed bacteria). These results were consistently observed throughout the study period. For determining the intraoral carrier state of patients with periodontitis, a combined sample of supra- and subgingival plaque taken from the deepest periodontal pocket in each sextant may yield the most reliable result. This sampling strategy may be used in routine microbial testing and clinical research.