Microbial colonization patterns predict the outcomes of surgical treatment of infrabony defect

Aim: To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects. Materials and Methods: One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of 43mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA\u2013DNA checkerboard analysis. Results: Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (43 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery. Conclusions: Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatmen

Bacillus anthracis Peptidoglycan Stimulates an Inflammatory Response in Monocytes through the p38 Mitogen-Activated Protein Kinase Pathway

We hypothesized that the peptidoglycan component of B. anthracis may play a critical role in morbidity and mortality associated with inhalation anthrax. To explore this issue, we purified the peptidoglycan component of the bacterial cell wall and studied the response of human peripheral blood cells. The purified B. anthracis peptidoglycan was free of non-covalently bound protein but contained a complex set of amino acids probably arising from the stem peptide. The peptidoglycan contained a polysaccharide that was removed by mild acid treatment, and the biological activity remained with the peptidoglycan and not the polysaccharide. The biological activity of the peptidoglycan was sensitive to lysozyme but not other hydrolytic enzymes, showing that the activity resides in the peptidoglycan component and not bacterial DNA, RNA or protein. B. anthracis peptidoglycan stimulated monocytes to produce primarily TNFα; neutrophils and lymphocytes did not respond. Peptidoglycan stimulated monocyte p38 mitogen-activated protein kinase and p38 activity was required for TNFα production by the cells. We conclude that peptidoglycan in B. anthracis is biologically active, that it stimulates a proinflammatory response in monocytes, and uses the p38 kinase signal transduction pathway to do so. Given the high bacterial burden in pulmonary anthrax, these findings suggest that the inflammatory events associated with peptidoglycan may play an important role in anthrax pathogenesis

Intratracheal administration of endotoxin and cytokines: VIII. LPS induces E-selectin expression; anti-E-selectin and soluble E-selectin inhibit acute inflammation

E-selectin is an inducible endothelial adhesion molecule that binds neutrophils. E-selectin mRNA is not constitutively detectable in the lungs of rats. Intratracheal injection of LPS induces pulmonary E-selectin mRNA expression at 2–4 h. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of mouse F(ab′) 2 or F(ab′)) anti-E-selectin monoclonal antibody inhibits the emigration of neutrophils into the bronchoalveolar space at 6 h by 50–70%. TNF and IL-6 bioactivity are not decreased in bronchoalveolar lavage fluid after treatment with anti-E-selectin antibody as compared to controls, suggesting that the anti-E-selectin does not affect the magnitude of the LPS-initiated cytokine cascade. Intratracheal injection of LPS followed at 2 and 4 h by intravenous injection of soluble E-selectin inhibits neutrophilic emigration at 6 h by 64%, suggesting that endogenous soluble E-selectin shed from activated endothelium may play a role in the endogenous down-regulation of acute inflammation. E-selectin-mediated adhesion of neutrophils to endothelium appears crucial to the full development of the acute inflammation response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44513/1/10753_2005_Article_BF01534436.pd

The simplified papilla preservation flap in the regenerative treatment of deep intrabony defects: Clinical outcomes and postoperative morbidity

Background: The aims of the present multi-center, randomized, controlled clinical trial were: 1) to compare the efficacy of the simplified papilla preservation flap with and without a barrier membrane in deep intrabony defects; 2) to evaluate the postoperative morbidity and surgical complications; and 3) to preliminarily test the impact of baseline tooth mobility on clinical outcomes. Methods: This parallel group, randomized, multi-center, controlled clinical trial involved 112 patients in 8 periodontal practices in 4 countries. A deep intrabony defect in each patient was accessed with the simplified papilla preservation flap. In the test defects, a bioabsorbable membrane was positioned. Patients' experiences with the surgical procedure and postoperative period were evaluated with a questionnaire. Clinical outcomes included clinical attachment level (CAL) and probing depth (PD) changes. Results: Complete observations were available for 55 test and 54 control defects. CAL gains at 1 year were 3.5 ± 2.1 mm in the guided tissue regeneration (GTR) group and 2.6 ± 1.8 mm in the control group (P= 0.0117). CAL gains ≥4 mm were observed in 50.9% of GTR sites and 33.3% of control sites. A significant center effect of 2.1 mm was observed (P = 0.01). Initial PD (P = 0.01) and baseline tooth mobility (P = 0.036) were significant covariates. During the procedure, 30.4% of test and 28.6% of controls reported feeling moderate pain, and subjects estimated the hardship of the procedure at 24 ± 25 visual analog scale (VAS) units in the test group, and at 22 ± 23 VAS in controls. In terms of the investigated outcomes, differences between test and control groups were not statistically significant. Among the postoperative complications, edema was most prevalent at week 1, and more frequently associated with the test treatment (P = 0.01). In the test group, 53.6% of membranes were exposed at week 3. Conclusions: The present study further supports the added benefits of guided tissue regeneration with respect to access flap alone in the treatment of deep intrabony defects, as well as the general efficacy of GTR in different clinical settings. Furthermore, our study indicates a possible influence of baseline tooth mobility on clinical outcomes.link_to_subscribed_fulltex

Clinical outcomes following treatment of human intrabony defects with GTR/bone replacement material or access flap alone: A multicenter randomized controlled clinical trial

Aim: This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material. Materials and Methods: One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed. Results: One year after treatment, the test defects gained 3.3 ± 1.7mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5 ± 1.5 mm. Pocket reduction was also significantly higher in the test group (3.7 ± 1.8 mm) when compared with the controls (3.2 ± 1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR = 2.6, 95% CI 1.2-5.4) and by starting with deeper PPD (OR = 1.7, 1.3-2.2) but were decreased by receiving treatment at the worst-performing clinical center (OR = 0.9, 0.76-0.99). Conclusions: The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone. © Blackwell Munksgaard, 2004.link_to_subscribed_fulltex

Clinical outcomes following treatment of human intrabony defects with GTR/bone replacement material or access flap alone: A multicenter randomized controlled clinical trial

Aim: This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material. Materials and Methods: One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of ≥ 3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed. Results: One year after treatment, the test defects gained 3.3 ± 1.7mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5 ± 1.5 mm. Pocket reduction was also significantly higher in the test group (3.7 ± 1.8 mm) when compared with the controls (3.2 ± 1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR = 2.6, 95% CI 1.2-5.4) and by starting with deeper PPD (OR = 1.7, 1.3-2.2) but were decreased by receiving treatment at the worst-performing clinical center (OR = 0.9, 0.76-0.99). Conclusions: The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone. © Blackwell Munksgaard, 2004

Guided tissue regeneration/deproteinized bovine bone mineral or papilla preservation flaps alone for treatment of intrabony defects. II: radiographic predictors and outcomes

Objectives: This study reports the secondary analysis of a randomized-controlled clinical trial designed to assess the efficacy of deproteinized bovine mineral and a collagen membrane in the treatment of intrabony defects. The specific aims of this report are (1) to analyse the radiographic bone changes 1 year after therapy and (2) to assess the association between radiographic defect angle and treatment outcomes. Materials and Methods: Baseline and 12-month radiographs were collected from 120 patients with advanced chronic periodontitis from 10 centres in seven countries as part of a multi-centre clinical trial. All patients had at least one intrabony defect X3mm in depth. The treatment consisted of simplified or modified papilla preservation flaps to access the defect. After debridement of the area, a deproteinized bovine mineral and a collagen membrane were applied in the test subjects, and omitted in the controls. Main outcome measures were radiographic bone fill and defect resolution 1 year after surgery. Results: One hundred and twenty pairs of radiographs were obtained, of which 110 pairs were measurable (57 tests and 53 controls). One year after treatment, radiographic resolution of the intrabony component was significantly higher in the test group (3.2 1.7mm) when compared with the controls (1.7 1.9mm). Multivariate analysis indicated that the treatment and the baseline radiographic depth of the intrabony defect significantly influenced the radiographic bone fill of the intrabony defect 1 year following treatment. The percentage of resolution of the defect was influenced by the treatment provided and the baseline plaque score. The baseline radiographic defect angle did not show a significant impact on the clinical and radiographic outcomes. Conclusions: Regenerative periodontal surgery with a deproteinized bovine bone mineral and a collagen membrane offered additional benefits in terms of radiographic resolution of the intrabony defect and predictability of outcomes with respect to papilla preservation flaps alone