Empirical or microbiologically guided systemic antimicrobials as adjuncts to non-surgical periodontal therapy? A systematic review

BACKGROUND: It is unclear if patients with specific subgingival microbiological profiles benefit more from adjunctive systemic antibiotics.AIMS: To answer the question: 'What is the clinical benefit in periodontitis patients taking adjunctive systemic antimicrobials to non-surgical therapy, depending on pre-treatment detection of periodontopathogenic bacteria?'MATERIALS AND METHODS: A search was conducted in 4 electronic databases for randomised controlled trials reporting clinical outcomes following adjunctive antibiotic therapy for patients divided by baseline microbiological profiles.RESULTS: The initial search resulted in 643 papers, reduced to 5 after screening and author contact. Four of these studies were suitable for a fixed effects two-stage individual participant data meta-analysis adjusted for baseline data. Collectively, adjunctive Amoxicillin and Metronidazole yielded superior clinical results (measured as reduction of PPDs) compared to placebo. No significant differences were detected for the effect of adjunctive antibiotics by detection of A. actinomycetemcomitans on PPDs ≥ 5 mm (WMD=1.16, 95% CI[-5.37, 7.68], I2 =37.8%) or other clinical outcomes. All included studies had low risk of bias.CONCLUSION: There is no evidence to suggest that baseline detection of periodontopathogenic bacteria should be used as criterion for prescribing adjunctive antibiotics, although only limited information on microbial data and specific antimicrobials were available for analysis.</p

Antibiotics prescribing practices in oral implantology among jordanian dentists. A cross sectional, observational study

<p>Abstract</p> <p>Background</p> <p>In oral implantology, there is no consensus on the most appropriate regimen for antibiotics prescribing, the decision to prescribe antibiotic is usually based on procedure, patient and clinician related factors. The aim of this study was to investigate the rationale of antibiotic prescribing among Jordanian clinicians who practice oral implantology.</p> <p>Findings</p> <p>The target sample for the study was the 250 Jordan Dental Implant Group members. A five page questionnaire contained 41 questions, both closed and open questions were used to collect data. Statistical analysis was performed using SPSS Windows 16.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics were generated.</p> <p>The response rate was (70.4%) 176/250. Mean age was 37.2 yrs, 49.4% always prescribe antibiotics mainly oral amoxicillin and amoxicillin with clavulinic acid. Antibiotics prescribing increased with flap raising, multiple implants and sinus or bone augmentation. Patient medical condition, periodontitis and oral hygiene were the most important clinical factors in antibiotic prescribing, non-clinical factors were; reading scientific materials, courses and lectures, knowledge gained during training, and the effectiveness and previous experience with the drug.</p> <p>Conclusions</p> <p>Wide variations in antibiotics types, routes, dose and duration of administration were found. Recommendations on antibiotic prescribing are needed to prevent antibiotic overprescribing and misuse.</p

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections

Imaging interfaces in epitaxial heterostructures.

We present high resolution electron density maps of two types of systems investigated. The first type consists of two InAs films grown on GaSb (001) substrates (one grown using As4, the other one grown using As 2) and two GaSb films grown on InAs (001). The semiconductor samples were 9 monolayers thick and were grown using MBE. The three dimensional electron densities were obtained measuring the intensities along the Bragg rods and analyzing them with the newly developed Coherent Bragg Rod Analysis (COBRA) phase retrieval method. The study represents the first attempt to use a phase retrieval method in the characterization of a buried semiconductor heterostructure. The semiconductor was treated as a quaternary of form Ga mIn1-mAs nSb1-n. The m(z) and n( z) compositional fractions and the vertical lattice spacing profiles were extracted. The results tend to indicate that the transition regions have a quaternary composition and are relatively narrow (1.5 unit cells). In the case of the GaSb film, significant presence of As is observed. The lattice constant in the film is not constant and has a minimum &sim;1.5 unit cells below the surface. The second type of system investigated consists of a thin film of PbTiO 3 on SrTiO3 (001), with and without a Pt electrode on top. The 50 A thick PbTiO3 film was grown by sputtering. The ED maps were investigated for peak position shifts. The O1 lattice seems to be shifted toward the film substrate interface in the case of the bare film. In the case of the Pt electrode region, its behavior is more complex. The O2 sublattice exhibits a shift toward the surface of the film, with a maximum of &sim;0.25 A at 12 unit cells away from the substrate. The effect relaxes toward the surface. In the case of the bare film, the Ti peak width is slightly increased in the vicinity of both film interfaces. The presence of the Pt electrode seems to inhibit this behavior, fact that can be correlated with the inhibition of the presence of surface charge.Ph.D.Condensed matter physicsPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/124762/2/3163774.pd