Short-term effects of systemic antibiotics during periodontal healing.

OBJECTIVES: To investigate the short-term effects of nonsurgical therapy (scaling and root planing, SRP) on the subgingival microbiota in chronic (CP) and aggressive (AP) periodontal disease. METHOD AND MATERIALS: Ninety-seven CP and AP subjects underwent full-mouth SRP on 2 consecutive days. AP patients were randomly assigned to either receive systemic metronidazole plus amoxicillin (AP+AB) or were treated mechanically alone (AP). Pathogens were identified with 16S rRNA oligodeoxynucleotide probes and dot-blot hybridization before and at days 2, 3, 4, 7, 10, and 21 of healing. CP subjects were treated by scaling and root planing along with placebo tablets. RESULTS: Initially, AP cell counts were 69.9- (Porphyromonas gingivalis), 10.2- (Aggregatibacter actinomycetemcomitans), 5.7- (Tannerella forsythia), and 3.3-fold (Prevotella intermedia) enhanced compared to CP cell counts. Following SRP, immediate elimination occurred in single individuals of all three treatment groups at day 2. After SRP plus antibiotic therapy (AP+AB), the prevalence scores dropped beyond the levels of AP and CP, beginning at day 7, and remained low until day 21 (P =or< .05). Clinical healing statistically benefited from SRP with no differences among the three treatment groups. CONCLUSION: Nonsurgical therapy resulted in both a suppression and early elimination of single taxa immediately after completion of active treatment. Systemic antibiotics significantly accelerate the suppression of the periodontal microflora, but have limited effect on the elimination of target isolates during healing.

Activation of cyclic AMP response element-binding protein (CREB) in aggressive periodontal disease.

OBJECTIVES: To report a novel observation of neutrophil signal transduction abnormalities in patients with localized aggressive periodontitis (LAP) that are associated with an enhanced phosphorylation of the nuclear signal transduction protein cyclic AMP response element-binding factor (CREB). METHOD AND MATERIALS: Peripheral venous blood neutrophils of 18 subjects, 9 patients with LAP and 9 race-, sex-, and age-matched healthy controls, were isolated and prepared using the Ficoll-Hypaque density-gradient technique. Neutrophils (5.4 x 10(6)/mL) were stimulated with the chemoattractant FMLP (10(-6) mol/L) for 5 minutes and lysed. Aliquots of these samples were separated by SDS-PAGE (60 microg/lane) on 9.0% (w/v) polyacrylamide slab gels and transferred electrophoretically to polyvinyl difluoride membranes. The cell lysates were immunoblotted with a 1:1,000 dilution of rabbit-phospho-CREB antibody that recognizes only the phosphorylated form of CREB at Ser133. The activated CREB was visualized with a luminol-enhanced chemoluminescence detection system and evaluated by laser densitometry. RESULTS: In patients with LAP, the average activation of CREB displayed an overexpression for the unstimulated peripheral blood neutrophils of 80.3% (17.5-fold) compared to healthy controls (4.6%). CONCLUSION: LAP neutrophils who express their phenotype appear to be constitutively primed, as evidenced by activated CREB in resting cells compared to normal individuals. The genetically primed neutrophil phenotype may contribute to neutrophil-mediated tissue damage in the pathogenesis of LAP.

Change of antibiotic susceptibility following periodontal therapy. A pilot study in aggressive periodontal disease.

BACKGROUND: The hypothesis was tested that bacterial susceptibilities in aggressive periodontitis change upon administration of systemic antibiotics as adjuncts to periodontal therapy. METHODS: In 23 subjects (average age 38.9+/-6.7 years) with aggressive periodontitis, microbial parameters were assessed prior to and 1 year after completion of comprehensive mechanical/surgical and systemic antimicrobial therapy. Following identification of five selected pathogens with the Rapid ID 32 A system, their susceptibilities towards amoxicillin/clavulanate potassium, metronidazole, and tetracycline were examined with the E-test. Antibiotics were administered according to the test results, and the minimal inhibitory concentrations (MIC90) were reevaluated after 1 year. Statistical analysis was performed on a patient basis, with the site data used for evaluation of the MIC levels. RESULTS: Bacterial MIC levels remained constant among the three antibiotic treatment groups compared with baseline. Mean MIC90 values ranged from <0.02 to 0.11 microg/ml (amoxicillin/clavulanate potassium), <0.02 to 0.27 microg/ml (metronidazole), and <0.02 to 0.11 microg/ml (tetracycline). Observed changes in susceptibility were attributed to the elimination of single bacterial taxa in the subgingival environment after antibiotic therapy. There were no statistically significant differences in clinical parameters among the treatment groups. Single tetracycline MICs were 1.5- to 6-fold enhanced compared to amoxicillin/clavulanate potassium and metronidazole. CONCLUSION: The periodontal pathogens investigated prior to and 1 year after periodontal therapy are tested sensitive to the antimicrobial agents. In aggressive periodontitis, changes in bacterial susceptibility upon the administration of systemic antibiotics are associated with the limited number of isolates tested following therapy.

The microflora recovered from the outer-surfaces of the Frialit-2 implanto-prosthetic connector.

The aim of the present investigation was to examine the outer-surface microbiota of the prosthetic connector of Frialit-2 implants, and to compare the microbial findings with the peri-implant parameters 2 years after functional loading. In 16 implant-treated patients (55.8 +/- 9.5 years) the outer-surface micro-organisms of the prosthetic connectors were determined in 32 Frialit-2 implants. The functional loading time of the prosthetic suprastructures was 24.1 +/- 13.8 months on average. After removal of the implant-supported restoration, microbial samples were obtained from the outer-surfaces of the Frialit-2 prosthetic connector. The microbial plaque samples were specified on CDC-blood agar as percentages of the total cultivable flora. Actinobacillus actinomycetemcomitans was semiquantitively determined on TSBV-agar in CFU/ml. The microbial plaque samples were dominated by Actinomyces israelii (68.8%), Eubacterium lentum (56.3%) and Veillonella parvula (43.8%) with proportions ranking between 3.9% (V. parvula) and 11.1% (A. israelii). The most frequently detected gram-negative microorganisms were Fusobacterium nucleatum (87.5%), Porphyromonas gingivalis (81.3%), and Peptostreptococcus micros (68.8%) with enhanced proportions for P. gingivalis (11.4%) and P. micros (11.4%). No statistical significant correlation could be established between the microbiota present on the outer-surfaces of the F2-connector and the peri-implant parameters examined. The outer-surface microflora recovered from the implanto-prosthetic-connector of Frialit-2 implants reveals a colonization with gram-positive bacteria and potentially harmful gram-negative micro-organisms that were frequently detected, but present at low levels. After 2 years of restorative loading, the outer-surface microbial colonization is compatible with peri-implant soft tissue health.

PMN responses in chronic periodontal disease: evaluation by gingival crevicular fluid enzymes and elastase-alpha-1-proteinase inhibitor complex.

OBJECTIVES: In the present trial, the hypothesis was examined that the local PMN responses in untreated and treated chronic periodontitis can be differentiated by gingival crevicular fluid lysosomal enzyme activities and elastase-alpha-1-proteinase inhibitor complex. METHODS: In nine subjects (average age 49.2 +/- 7.1 years) with chronic periodontitis, clinical parameters and markers of the PMN-derived inflammatory tissue response in gingival crevicular fluid (GCF) were assessed before and 6 months after surgical periodontal therapy. Myeloperoxidase (MPO), beta-N-acetyl-hexosaminidase (beta-NAH) and cathepsin D (CD) were analyzed as indicators of the PMN-associated host tissue destruction, and elastase-alpha-1-proteinase inhibitor complex (alpha-1-EPI) as the major serum protein inactivating PMN elastase. The total activities of the lysosomal enzymes MPO and beta-NAH were evaluated spectrophotometrically, the CD levels by liquid scintillation counting with [14C] hemoglobin as substrate, and the total alpha-1-proteinase inhibitor complex using a sandwich-immunoassay. RESULTS: The clinical parameters revealed a statistical significant decrease at the 6-month reexamination. PD levels dropped from 5.40 to 2.88 mm (change 2.52 +/- 1.04 mm), the CAL scores from 6.67 to 4.43 mm (change 2.24 +/- 0.77 mm). The 30 s GCF volumes dropped from 129.8 to 68.6, displaying a change of 61.1 +/- 18.6, p

Resolution of crevicular fluid leukocyte activity in patients treated for aggressive periodontal disease.

BACKGROUND: Enhanced neutrophil responses play a critical role in the activation of the innate immune system and causation of aggressive periodontitis (AgP). The hypothesis that comprehensive periodontal treatment expedites resolution of amplified leukocyte activity and facilitates the reconstitution of periodontal health was tested. METHODS: Four different gingival crevicular fluid (GCF) markers from 14 patients were characterized prior to and at 3, 6, 12, 24, and 36 months after periodontal therapy. GCF myeloperoxidase (MPO), beta-N-acetyl-hexosaminidase (beta-NAH), and beta-glucuronidase (beta-G) were determined spectrophotometrically, and cathepsin D (CD) by liquid scintillation counting using [14C] hemoglobin as substrate. The primary outcome was long-term stability of periodontal health. RESULTS: In untreated AgP, GCF markers were significantly amplified (MPO: 1.9-fold; beta-NAH: 1.3-fold; beta-G: 1.7-fold; CD: 4.7-fold). Following periodontal therapy, the leukocyte activity was significantly dampened (0.3- to 0.5-fold), and paralleled with a sustained improvement of periodontal health (P < 0.05). Thereafter and at 3 years, GCF leukocyte responses remained on a physiologic low level compatible to normal immune function. CONCLUSIONS: Comprehensive treatment of AP induces a downregulation of amplified crevicular neutrophil activity. The release of the innate immune system from exacerbating damage elicits a successful reconstitution of long-term periodontal health with no setbacks seen after 3 years.

Aggressive periodontitis: 5-year follow-up of treatment.

BACKGROUND: The hypothesis that in subjects with aggressive periodontitis, a long-term stability of periodontal health can be achieved following comprehensive mechanical/surgical and systemic antimicrobial therapy was tested in this prospective study. METHODS: Thirteen patients (36.9+/-7.4 years) with aggressive periodontitis were monitored before and up to 5 years following periodontal therapy. Clinical attachment levels (CAL) were assessed pretherapy, and at 3 months following completion of active periodontal therapy supplemented by amoxicillin plus metronidazole. All subjects were subsequently enrolled in a maintenance program and provided with supportive periodontal therapy with 3 to 4 appointments annually. Reexaminations were performed after 6 months and 1, 2, 3, 4, and 5 years. The data were analyzed using the method of generalized estimating equations (GEE) for CAL changes from baseline to the 3-month visit, and from completion of periodontal therapy to each annual visit up to the 5-year follow-up reappointment. RESULTS: During the 5-year study, all subjects strongly benefited from periodontal treatment. Between baseline and the 3-month reexamination, the CAL levels revealed a significant decrease of 2.23 mm (95% confidence interval [CI]: 1.77 to 2.69 mm; P < or =0.001). At the 5-year maintenance visit, the CAL changes ranged from -0.04 to +0.29 mm with no further statistically significant periodontal breakdown (P >0.05). Five years after surgery, 3.2% of the treated sites demonstrated a further CAL gain > or =3 mm. A stabilization (CAL -2 to +2 mm) occurred in 94.6% of the cases. The number of periodontal sites experiencing a breakdown varied from 5.3% at 6 months to 2.2% at 5 years. CONCLUSIONS: In aggressive periodontitis, comprehensive mechanical/surgical and antimicrobial therapy is an appropriate treatment regimen for long-term stabilization of periodontal health. In this study, periodontal disease progression was successfully arrested in 95% of the initially compromised lesions, while 2% to 5% experienced discrete or recurrent episodes of loss of periodontal support.