Java project on periodontal diseases: causes of tooth loss in a cohort of untreated individuals.

OBJECTIVE: To assess the relative contribution of caries and periodontal disease to tooth loss over 24 years in a cohort deprived of regular dental care. MATERIAL & METHODS: The study population consisted of 98 subjects from a tea estate on West Java, Indonesia, that had been part of a prospective longitudinal study and provided full datasets of clinical assessments between 1987, 1994 and 2002. In 2011, complete sets of dental radiographs were made which was combined with the survey forms and clinical slides from the previous assessments in order to estimate reasons for tooth loss. RESULTS: Thirty-seven subjects lost no teeth, whereas 61 subjects lost 185 teeth. In this group, 45.9% lost ≤2 teeth, 32.8% lost 3 to 4 teeth and 19.7% lost ≥5 teeth. The majority of teeth were lost due to caries. In five subjects, tooth loss could be attributed solely to periodontitis, whereas in four subjects teeth were lost due to both caries and periodontits. Analyses of the predictor variables age, gender, smoking, education, presence of caries and severe periodontitis showed that male gender and caries were significantly associated with tooth loss. CONCLUSION: The majority of teeth in this population were lost due to caries.

Porphyromonas Gingivalis and E-coli induce different cytokine production patterns in pregnant women.

OBJECTIVE: Pregnant individuals of many species, including humans, are more sensitive to various bacteria or their products as compared with non-pregnant individuals. Pregnant individuals also respond differently to different bacteria or their products. Therefore, in the present study, we evaluated whether the increased sensitivity of pregnant women to bacterial products and their heterogeneous response to different bacteria was associated with differences in whole blood cytokine production upon stimulation with bacteria or their products. METHODS: Blood samples were taken from healthy pregnant and age-matched non-pregnant women and ex vivo stimulated with bacteria or LPS from Porphyromonas Gingivalis (Pg) or E-coli for 24 hrs. TNFα, IL-1ß, IL-6, IL-12 and IL-10 were measured using a multiplex Luminex system. RESULTS: We observed a generally lower cytokine production after stimulation with Pg bacteria or it's LPS as compared with E-coli bacteria. However, there was also an effect of pregnancy upon cytokine production: in pregnant women the production of IL-6 upon Pg stimulation was decreased as compared with non-pregnant women. After stimulation with E-coli, the production of IL-12 and TNFα was decreased in pregnant women as compared with non-pregnant women. CONCLUSION: Our results showed that cytokine production upon bacterial stimulation of whole blood differed between pregnant and non-pregnant women, showing that the increased sensitivity of pregnant women may be due to differences in cytokine production. Moreover, pregnancy also affected whole blood cytokine production upon Pg or E-coli stimulation differently. Thus, the different responses of pregnant women to different bacteria or their products may result from variations in cytokine production.

Treatment of periodontitis improves the atherosclerotic profile: a systematic review and meta-analysis.

AIM: Systematic review and meta-analyses to study the robustness of observations that treatment of periodontitis improves the atherosclerotic profile. MATERIAL AND METHODS: Literature was searched in Medline-PubMed, Cochrane CENTRAL and EMBASE, based on controlled periodontal intervention trials, including also a non-intervention group. Data were extracted and meta-analyses were performed. RESULTS: From 3928 screened studies, 25 trials met the eligibility criteria. These trials enrolled 1748 periodontitis patients. Seven trials enrolled periodontitis patients that were otherwise healthy, 18 trials recruited periodontal patients with various co-morbidities, such as CVD or diabetes. None of the trials used hard clinical endpoints of CVD. However, improvement of endothelial function has been consistently reported. Meta-analyses demonstrated significant weighted mean difference (WMD) for hsCRP (-0.50 mg/l, 95% CI:-0.78; -0.22), IL-6 (-0.48 ng/l, 95% CI: -0.90; -0.06), TNF-α (-0.75 pg/ml, 95% CI: -1.34; -0.17), fibrinogen (-0.47 g/l, 95% CI: -0.76; -0.17), total cholesterol (-0.11 mmol/l, 95% CI: -0.21; -0.01) and HDL-C (0.04 mmol/l, 95% CI: 0.03; 0.06) favouring periodontal intervention. Importantly, periodontitis patients with co-morbidity benefitted most from periodontal therapy; significant WMD were observed for levels of hsCRP (-0.71 mg/l, 95% CI: -1.05; -0.36), IL-6 (-0.87 ng/l, 95% CI: -0.97; -0.78), triglycerides (-0.24 mmol/l, 95% CI: -0.26; -0.22), total cholesterol (-0.15 mmol/l, 95% CI: -0.29; -0.01), HDL-C (0.05 mmol/l, 95% CI: 0.03; 0.06) and HbA1c (-0.43%, 95% CI: -0.60; -0.25). CONCLUSIONS: This systematic review and meta-analyses demonstrate that periodontal treatment improves endothelial function and reduces biomarkers of atherosclerotic disease, especially in those already suffering from CVD and/or diabetes.

Gingival labial recessions in orthodontically treated and untreated individuals: a case - control study.

OBJECTIVES: To evaluate the long-term development of labial gingival recessions during orthodontic treatment and retention phase. MATERIAL AND METHODS: In this retrospective case-control study, the presence of gingival recession was scored (Yes or No) on plaster models of 100 orthodontic patients (cases) and 120 controls at the age of 12 (T12 ), 15 (T15 ), 18 (T18 ), and 21 (T21 ) years. In the treated group, T12 reflected the start of orthodontic treatment and T15 - the end of active treatment and the start of retention phase with bonded retainers. Independent t-tests, Fisher's exact tests and a fitted two-part "hurdle" model were used to identify the effect of orthodontic treatment/retention on recessions. RESULTS: The proportion of subjects with recessions was consistently higher in cases than controls. Overall, the odds ratio for orthodontic patients as compared with controls to have recessions is 4.48 (p < 0.001; 95% CI: 2.61-7.70). CONCLUSIONS: Within the limits of the present research design, orthodontic treatment and/or the retention phase may be risk factors for the development of labial gingival recessions. In orthodontically treated subjects, mandibular incisors seem to be the most vulnerable to the development of gingival recessions.

Prevalence and severity of periodontitis in Indonesian patients with rheumatoid arthritis.

BACKGROUND: Patients with rheumatoid arthritis (RA) may have more prevalent and severe periodontitis than healthy controls. Periodontitis may increase the systemic inflammation in RA. The aim of this study is to assess periodontitis prevalence and severity and its potential association with systemic inflammation in Indonesian patients with RA. METHODS: A full-mouth periodontal examination including probing depth, gingival recession, plaque index, and bleeding on probing was performed in 75 Indonesians with RA and 75 age-, sex-, and smoking-matched Indonesian controls. A validated questionnaire was used to assess smoking, body mass index, education, and medical conditions. In addition, in all participants, the use of drugs was noted, and erythrocyte sedimentation rates and serum levels of high-sensitivity C-reactive protein (hsCRP), rheumatoid factor, and anti-citrullinated protein antibodies were measured. Differences in periodontitis prevalence and 12 measures of periodontitis severity between patients with RA and controls were analyzed using univariate analyses. RESULTS: No significant differences in periodontitis prevalence and 11 measures of periodontitis severity between patients with RA and controls were observed. Conversely, patients with RA had a significantly lower surface area of healthy pocket epithelium versus controls (P = 0.008), and a tendency toward higher hsCRP levels was observed in patients with RA with severe periodontitis compared with patients with RA with no mild or moderate periodontitis (P = 0.063). It has to be noted that all patients with RA were on anti-inflammatory drugs, whereas none of the controls used such drugs. CONCLUSION: Prevalence and severity of periodontitis in Indonesian patients with RA is comparable to controls but with less healthy pocket epithelium than in controls and a tendency toward a higher inflammatory state in patients with RA and severe periodontitis.

Cytokine production induced by non-encapsulated and encapsulated Porphyromonas gingivalis strains.

OBJECTIVE: Although the exact reason is not known, encapsulated gram-negative Porphyromonas gingivalis strains are more virulent than non-encapsulated strains. Since difference in virulence properties may be due to difference in cytokine production following recognition of the bacteria or their products by the host inflammatory cells, we compared cytokine production following stimulation with bacteria or lipopolysaccharides (LPS) of a non-encapsulated and an encapsulated P. gingivalis strain (K(-) and K1). DESIGN: Tumour necrosis factor-alpha (TNF-α) production following stimulation of the cell-line Mono Mac 6 with bacteria or LPS of both P. gingivalis strains was determined using flow cytometry. Furthermore, we investigated the effects of the two P. gingivalis strains or their LPS on TNF-α and Interleukin (IL-1ß, IL-6, IL-12 and IL-10) production in whole blood using Luminex. In both experiments, Escherichia coli bacteria and LPS were used as a reference. RESULTS: Both P. gingivalis strains induced lower cytokine production than E. coli with the exception of IL-6. P. gingivalis K1 bacteria elicited a higher overall cytokine production than P. gingivalis K(-). In contrast, P. gingivalis K1 LPS stimulation induced a lower cytokine production than P. gingivalis K(-) LPS. CONCLUSIONS: Our findings suggest that the encapsulated P. gingivalis K1 bacteria induce higher cytokine production than the non-encapsulated P. gingivalis K(-). This was not due to its LPS. The stronger induction of cytokines may contribute to the higher virulence of P. gingivalis K1.

The periodontium of periodontitis patients contains citrullinated proteins which may play a role in ACPA (anti-citrullinated protein antibody) formation.

AIM: To determine the presence and location (stroma versus epithelium) of citrullinated proteins in periodontitis tissue as compared to non-periodontitis tissue and synovial tissue of RA patients. MATERIALS & METHODS: Periodontitis, healthy periodontal and RA-affected synovial tissue samples were collected in addition to buccal swabs. These samples were stained for the presence of citrullinated proteins using polyclonal (Ab5612) and monoclonal (F95) antibodies. Furthermore, Western blotting with F95 was performed on lysates prepared from periodontal and synovial tissues. RESULTS: In periodontitis stroma, increased citrullinated protein presence (80%) was observed compared with control stroma (33%), the latter was associated with inflammation of non-periodontitis origin. Periodontal epithelium always stained positive for Ab5612. Noteworthy, only periodontitis-affected epithelium stained positive for F95. All buccal mucosal swabs and 3 of 4 synovial tissue samples stained positive for both Ab5612 and F95. Western blotting with F95 showed presence of similar citrullinated proteins in both periodontitis and RA-affected synovial tissue. CONCLUSION: Within the periodontal stroma, citrullination is an inflammation-depended process. In periodontal epithelium, citrullination is a physiological process. Additional citrullinated proteins are formed in periodontitis, apparently similar to those formed in RA-affected synovial tissue. Periodontitis induced citrullination may play a role in the aetiology of rheumatoid arthritis.

Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients.

OBJECTIVES: Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims. MATERIALS AND METHODS: First, volunteers brushed 2 weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12 h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis. RESULTS: The viabilities of plaques after brushing with Colgate-Total® and Crest-Pro-Health® were smaller than of control plaques and up to 12 h after brushing with Crest-Pro-Health® plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes. CONCLUSIONS: Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health®). CLINICAL RELEVANCE: The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.

Periodontal inflamed surface area and C-reactive protein as predictors of HbA1c: a study in Indonesia.

UNLABELLED: Periodontitis may exert an infectious and inflammatory burden, evidenced by increased C-reactive protein (CRP). This burden may impair blood glucose control (HbA1c). The aim of our study was to analyze whether periodontitis severity as measured with the periodontal inflamed surface area (PISA) and CRP predict HbA1c levels in a group of healthy Indonesians and a group of Indonesians treated for type 2 diabetes mellitus (DM2). A full-mouth periodontal examination, including probing pocket depth, gingival recession, clinical attachment loss, plaque index and bleeding on probing, was performed in 132 healthy Indonesians and 101 Indonesians treated for DM2. Using these data, PISA was calculated. In addition, HbA1c and CRP were analyzed. A validated questionnaire was used to assess smoking, body mass index (BMI), education and medical conditions. In regression analyses, it was assessed whether periodontitis severity and CRP predict HbA1c, controlling for confounding and effect modification (i.e., age, sex, BMI, pack years, and education). In healthy Indonesians, PISA and CRP predicted HbA1c as did age, sex, and smoking. In Indonesians treated for DM2, PISA did not predict HbA1c. Periodontitis may impair blood glucose regulation in healthy Indonesians in conjunction with elevated CRP levels. The potential effect of periodontitis on glucose control in DM2 patients may be masked by DM2 treatment. CLINICAL RELEVANCE: periodontitis may impair blood glucose control through exerting an inflammatory and infectious burden evidenced by increased levels of CRP.

Acute and substantive action of antimicrobial toothpastes and mouthrinses on oral biofilm in vitro.

The aim of this study was to compare acute action by killing or disrupting oral biofilms through the use of antimicrobial toothpastes and mouthrinses in vitro and to investigate substantive action by absorption of antimicrobials in a biofilm. Biofilms from freshly collected human saliva were grown in 96-well microtitre plates. After removal of saliva, the wells of the microtitre plates were washed with sterile water (control), or exposed to a dilution series of mouthrinses (Corsodyl, Listerine, Meridol, Crest Pro Health) or to toothpaste slurries (Prodent Coolmint, Colgate Total, Zendium Classic, Crest Pro Health, Oral B Pro Expert, Crest Cavity Protection). Acute action was concluded from reduced continued (16 h) growth of treated biofilms with respect to the control. Substantive action was studied by exposing dead biofilms to mouthrinses or to toothpaste slurry. Substantive action through the absorption and subsequent release of antimicrobials from biofilm was concluded from reduced growth on top of the treated biofilms. All formulations showed acute action at the highest concentrations studied. Further dilution yielded loss of efficacy, or even stimulation of biofilm growth. Antimicrobial absorption in and the release of effective concentrations of antimicrobials from dead biofilms, was demonstrated for three selected antimicrobial products, indicating that antimicrobials remain bio-available for substantive action on new biofilms.

Efficacy of natural antimicrobials in toothpaste formulations against oral biofilms in vitro.

OBJECTIVES: To evaluate the antimicrobial efficacies of two toothpaste formulations containing natural antimicrobials (herbal extracts and chitosan) against oral biofilms of different composition and maturational status. METHODS: Bacteria from a buffer suspension or fresh saliva were adhered for 2h to a salivary conditioning film and subsequently grown for 16h. Dual-species biofilms were prepared from Actinomyces naeslundii T14V-J1 and Streptococcus oralis J22, whilst multi-species biofilms were grown from freshly collected human saliva. Biofilms were exposed to 25wt% toothpaste supernatants. A chlorhexidine-containing mouthrinse and a buffer were used as positive- and negative-controls, respectively. Antibacterial efficacy was concluded from acute killing, bacterial removal, prevention of bacterial re-deposition and continued killing during re-deposition. RESULTS: The herbal- and chitosan-based supernatants showed immediate killing of oral biofilm bacteria, comparable with chlorhexidine. Moreover, exposure of a biofilm to these supernatants or chlorhexidine, yielded ongoing killing of biofilm bacteria after exposure during re-deposition of bacteria to a matured 16h biofilm, but not to a much thinner initial biofilm formed by 2h adhesion only. This suggests that thicker, more matured biofilms can absorb and release oral antimicrobials. CONCLUSIONS: Supernatants based on herbal- and chitosan-based toothpastes have comparable immediate and ongoing antibacterial efficacies as chlorhexidine. Natural antimicrobials and chlorhexidine absorb in oral biofilms which contributes to their substantive action.

Periodontitis prevalence and severity in Indonesians with type 2 diabetes.

BACKGROUND: The prevalence of diabetes mellitus type 2 (DM2) in Indonesia is high and still rising. Periodontitis is associated with DM2. No study has investigated this association in Indonesia, nor has any study investigated this association using a variety of methods to operationalize periodontitis. The present study compares prevalence and severity of periodontitis in patients with DM2 to healthy controls, using different methods to operationalize periodontitis. METHODS: A total of 78 subjects with DM2 and 65 healthy control subjects underwent a full-mouth periodontal screening assessing probing depth, gingival recession, plaque index, and bleeding on probing. Using these measurements, the prevalence and severity of periodontitis was operationalized in various ways. Differences in the prevalence and severity of periodontitis between subjects with DM2 and healthy subjects were analyzed using univariate analyses. In regression analyses, the prevalence and severity of periodontitis were predicted on the basis of DM2 presence, controlling for confounders and effect modification. RESULTS: Prevalence of periodontitis was significantly higher in subjects with DM2 compared to healthy subjects, showing odds ratios of 5.0 and 6.1. Likewise, periodontitis severity was significantly higher in subjects with DM2. CONCLUSION: Indonesian subjects with DM2 had more prevalent and more severe periodontitis than healthy Indonesian subjects, independent of confounding factors or the methods used to operationalize periodontitis.

In vitro oral biofilm formation on triclosan-coated sutures in the absence and presence of additional antiplaque treatment.

PURPOSE: This study evaluated the in vitro plaque inhibitory effect of triclosan-coated polyglactin 910 sutures in the absence and presence of an additional antiplaque agent commonly used after oral surgery. MATERIALS AND METHODS: Triclosan-coated sutures were incubated for 4 hours in freshly collected human saliva and, when appropriate, subsequently treated with an antiplaque rinse containing chlorhexidine-cetyl pyridinium as active components. Sutures without a triclosan-coating served as a control. RESULTS: Triclosan-coated sutures harbored similar amounts of plaque as did uncoated sutures. Exposure to the antiplaque rinse caused significant decreases in viable organisms for uncoated and triclosan-coated sutures. However, after application of the antiplaque rinse, more micro-organisms were found on triclosan-coated than on uncoated sutures. CONCLUSION: Sutures coated with triclosan do not provide a sufficient antimicrobial effect to prevent in vitro colonization by oral bacteria, whereas use in combination with a chlorhexidine-cetyl pyridinium-containing antiplaque rinse appears to be counterproductive.

Periodontal disease and pre-eclampsia: a systematic review.

AIM: This review evaluates the possible relationship between periodontal disease and pre-eclampsia, a major pregnancy complication. A generalized inflammatory response plays an important role in the pathogenesis of pre-eclampsia. Because periodontal disease is a low-grade inflammatory state, periodontal disease might contribute to the pathogenesis of pre-eclampsia. MAIN FINDINGS AND CONCLUSION: A literature search of PubMed, EMBASE and CINAHL until August 2010 revealed 12 eligible observational studies and three randomized-controlled trials (RCTs). It appeared difficult to compare these studies, due to variations in definitions of periodontal disease and pre-eclampsia, timing of periodontal examination and inadequate control for confounding factors. Eight observational studies reported a positive association, while four studies found no association. None of the RTCs reported reductions in pre-eclamptic rate after periodontal therapy during pregnancy. Therefore, it is questionable whether periodontal disease plays a causal role in the pathogenesis of pre-eclampsia. The observed association in eight observational studies might be the result of induction of periodontal disease due to the pre-eclamptic state or it may be an epiphenomenon of an exaggerated inflammatory response to pregnancy. Larger RCTs with pre-eclampsia as the primary outcome and pathophysiological studies are required to explore causality and to dissect biological mechanisms involved.

Increased prevalence of cardiovascular and autoimmune diseases in periodontitis patients: a cross-sectional study.

BACKGROUND: Associations between periodontitis and cardiovascular and autoimmune diseases are most often assessed in patients with a particular cardiovascular or autoimmune disease. To prevent selection bias, this study assesses the existence of associations between periodontitis and cardiovascular and autoimmune diseases in patients attending a dental or periodontal clinic. METHODS: Data were collected from 1,276 randomly selected dental records from patients attending a dental (n = 588) or periodontal (n = 688) clinic. Data on the prevalence of cardiovascular and autoimmune diseases were obtained from a validated health questionnaire. Data on the presence of periodontitis were taken from patients' dental records. RESULTS: In uncontrolled analyses, the prevalence of hypertension, diabetes mellitus (DM), and rheumatoid arthritis (RA) is significantly increased in patients with periodontitis. Controlled for confounding, periodontitis was associated with DM, with an odds ratio of 4 (1.03 to 15.3), in the dental clinic. DM was not associated with periodontitis in periodontal clinics. Hypertension does not seem to be associated with periodontitis when controlling for confounders. Periodontitis may be associated with RA in both clinic types. CONCLUSIONS: The increased prevalence of cardiovascular and autoimmune diseases among patients with periodontitis attending dental or periodontal clinics may, at least in part, be influenced by confounding. However, the increased prevalence of DM and RA in patients with periodontitis could not be explained by confounding.

The recolonization hypothesis in a full-mouth or multiple-session treatment protocol: a blinded, randomized clinical trial.

AIM: To test recolonization of periodontal lesions after full-mouth scaling and root planing (FM-SRP) or multiple session-SRP (MS-SRP) in a randomized clinical trial and whether FM-SRP and MS-SRP result in different clinical outcomes. MATERIALS AND METHODS: Thirty-nine subjects were randomly assigned to FM-SRP or MS-SRP groups. At baseline and after 3 months, probing pocket depth (PPD), plaque index (PlI) and bleeding on probing (BoP) were recorded. At baseline, immediately after treatment, after 1, 2, 7, 14 and 90 days, paper point samples from a single site from the maxillary right quadrant were collected for microbiological analysis of five putative pathogens by polymerase chain reaction. RESULTS: FM-SRP and MS-SRP resulted in significant reductions in PPD, BoP and PlI and the overall detection frequencies of the five species after 3 months without significant differences between treatments. Compared with MS-SRP, FM-SRP resulted in less recolonization of the five species, significantly for Treponema denticola, in the tested sites. CONCLUSION: FM-SRP and MS-SRP result in overall clinically and microbiologically comparable outcomes where recolonization of periodontal lesions may be better prevented by FM-SRP.

Oral biofilm architecture on natural teeth.

Periodontitis and caries are infectious diseases of the oral cavity in which oral biofilms play a causative role. Moreover, oral biofilms are widely studied as model systems for bacterial adhesion, biofilm development, and biofilm resistance to antibiotics, due to their widespread presence and accessibility. Despite descriptions of initial plaque formation on the tooth surface, studies on mature plaque and plaque structure below the gum are limited to landmark studies from the 1970s, without appreciating the breadth of microbial diversity in the plaque. We used fluorescent in situ hybridization to localize in vivo the most abundant species from different phyla and species associated with periodontitis on seven embedded teeth obtained from four different subjects. The data showed convincingly the dominance of Actinomyces sp., Tannerella forsythia, Fusobacterium nucleatum, Spirochaetes, and Synergistetes in subgingival plaque. The latter proved to be new with a possibly important role in host-pathogen interaction due to its localization in close proximity to immune cells. The present study identified for the first time in vivo that Lactobacillus sp. are the central cells of bacterial aggregates in subgingival plaque, and that Streptococcus sp. and the yeast Candida albicans form corncob structures in supragingival plaque. Finally, periodontal pathogens colonize already formed biofilms and form microcolonies therein. These in vivo observations on oral biofilms provide a clear vision on biofilm architecture and the spatial distribution of predominant species.

Oral biofilm models for mechanical plaque removal.

In vitro plaque removal studies require biofilm models that resemble in vivo dental plaque. Here, we compare contact and non-contact removal of single and dual-species biofilms as well as of biofilms grown from human whole saliva in vitro using different biofilm models. Bacteria were adhered to a salivary pellicle for 2 h or grown after adhesion for 16 h, after which, their removal was evaluated. In a contact mode, no differences were observed between the manual, rotating, or sonic brushing; and removal was on average 39%, 84%, and 95% for Streptococcus mutans, Streptococcus oralis, and Actinomyces naeslundii, respectively, and 90% and 54% for the dual- and multi-species biofilms, respectively. However, in a non-contact mode, rotating and sonic brushes still removed considerable numbers of bacteria (24-40%), while the manual brush as a control (5-11%) did not. Single A. naeslundii and dual-species (A. naeslundii and S. oralis) biofilms were more difficult to remove after 16 h growth than after 2 h adhesion (on average, 62% and 93% for 16- and 2-h-old biofilms, respectively), while in contrast, biofilms grown from whole saliva were easier to remove (97% after 16 h and 54% after 2 h of growth). Considering the strong adhesion of dual-species biofilms and their easier more reproducible growth compared with biofilms grown from whole saliva, dual-species biofilms of A. naeslundii and S. oralis are suggested to be preferred for use in mechanical plaque removal studies in vitro.

Dose-response relationship between periodontal inflamed surface area and HbA1c in type 2 diabetics.

BACKGROUND: A dose-response relationship between the amount of inflamed periodontal tissue and HbA1c level, might be indicative for a causal association between periodontitis and type 2 diabetes. AIM: To assess a dose-response relationship between the periodontal inflamed surface area (PISA), as a measure of the amount of inflamed periodontal tissue, and HbA1c levels in type 2 diabetics. MATERIAL AND METHODS: Forty consecutive dentate type 2 diabetics attending their general practitioner for regular check-up, underwent full-mouth probing pocket depth and bleeding on probing assessment. From these data PISA was calculated. HbA1c levels were retrieved from patients' medical files. The dose-response relationship between PISA and HbA1c levels was assessed using multiple linear regression analyses, controlling for factors that might influence PISA or HbA1c levels. RESULTS: The higher the PISA of type 2 diabetics was, the higher their HbA1c levels were. On a group level, an increase of PISA with 333 mm(2) was associated with a 1.0 percentage point increase of HbA1c, independent of the influence of other factors. CONCLUSION: On a group level, there is a dose-response relationship between PISA and HbA1c in type 2 diabetics. This might be an indication of a causal relationship between type 2 diabetes and periodontitis.