Ursula Platzer

In Vitro Activity of Moxifloxacin against Bacteria Isolated from Odontogenic Abscesses

ABSTRACT We evaluated the antimicrobial susceptibility of 87 pathogens isolated from 37 patients with odontogenic abscesses. The most prevalent bacteria were viridans group streptococci and Prevotella species. Considering all bacterial isolates, 100% were susceptible to amoxicillin-clavulanic acid, 98% were susceptible to moxifloxacin and to levofloxacin, 76% were susceptible to doxycycline, 75% were susceptible to clindamycin, and 69% were susceptible to penicillin.

Effect of different surface textures on retentive strength of tapered posts

STATEMENT OF PROBLEM Tapered posts allow for the preservation of tooth substance in the fragile apical area and are advantageous in clinical situations where they conform to the root and canal configuration of endodontically treated teeth. However, their lower retention compared with passive parallel-sided or active threaded posts is a disadvantage. PURPOSE This study determined the retentive strength of tapered titanium posts with different surface textures and examined the effect of roughening dentinal walls of the prepared post space. MATERIAL AND METHODS Posts with four surface configurations (smooth, with and without grooves, and sandblasted, with and without grooves) were examined when cemented in extracted anterior teeth. RESULTS The smooth post showed the lowest retentive strength. Sandblasting the smooth post more than doubled its retentive strength. The retentive strength of both smooth and sandblasted posts could be further increased by the addition of circumferential grooves. Roughening the dentinal walls of the prepared post space increased the retentive strength of sandblasted posts with and without grooves even more. CONCLUSIONS These findings indicated that, when a tapered post is used, roughening the dentin canal wall, as well as sandblasting and grooving the post, can provide statistically significant additional resistance to dislodgment.

Microbiological Analysis of a Prospective, Randomized, Double-Blind Trial Comparing Moxifloxacin and Clindamycin in the Treatment of Odontogenic Infiltrates and Abscesses

ABSTRACT The objective of this study was to identify the oral pathogens found in odontogenic infections, to determine their susceptibilities to amoxicillin-clavulanic acid (AMC), clindamycin (CLI), doxycycline (DOX), levofloxacin (LVX), moxifloxacin (MXF), and penicillin (PEN), and to search for associations between specific pathogens and types of infection. Swabs from patients enrolled in a randomized, double-blind phase II trial comparing MXF with CLI for the treatment of odontogenic abscesses or inflammatory infiltrates were cultured on media for aerobes and anaerobes. All bacterial isolates were identified at the species level. Overall, 205 isolates were cultured from 71 patients: 77 viridans group streptococci, 56 Prevotella spp., 19 Neisseria spp., 17 Streptococcus anginosus group isolates and hemolytic streptococci, 15 other anaerobes, and 21 other bacteria. Ninety-eight percent of pathogens were susceptible to MXF, 96% to AMC, 85% to LVX, 67% to PEN, 60% to CLI, and 50% to DOX. S. anginosus group and hemolytic streptococci were found significantly more frequently (P = 0.04) in patients with abscesses (12/95) than in patients with infiltrates (5/110). In four patients with infiltrates who failed to respond to CLI therapy, three isolates of the Streptococcus mitis group and four Neisseria spp. resistant to CLI were found. In this study, S. anginosus group and hemolytic streptococci were clearly associated with odontogenic abscesses. Our analysis suggests that viridans group streptococci and Neisseria spp. play a decisive role in the etiology of odontogenic infiltrates. The high in vitro activity of MXF against odontogenic bacteria corresponds well to its clinical results in the treatment of odontogenic abscesses and infiltrates.

Wear and hardness of different core build-up materials

Before crown preparation, teeth with extensive coronal destructions are built up with core materials. Sometimes, these build ups are exposed to the oral environment without the protection of crowns. Therefore, this in vitro investigation was aimed at evaluating the wear, surface roughness, Vickers hardness, and surface structure of 10 core composites, two glass ionomer cements (GICs), and four posterior restoration composites. The three-body wear was tested after water storage and 2,00,000 cycles. We measured both surface roughness and Vickers hardness (DIN 50133) and evaluated the surface structures by scanning electron microscopy. Results were statistically analyzed by use of the Mann-Whitney U test (alpha = 0.05). Lowest wear was found for the restorative composites (20 microm Grandio; others about 40 microm). A comparison of the composites Build-It, Chroma Core, Rebilda LC, and Rebilda DC to Quixfil showed similar wear values for each material (43-50 microm). Wear values of GICs and all others core composites ranged between 58 and 75 microm. Only Ti-Core showed significantly higher wear than all other materials (p < 0.05). All core materials except Ti-Core (35 HV) showed Vickers hardness values between 42 and 61 HV. Most core composites, particularly Build-It, Multicore Flow, Rebilda LC, Ecusit, and Tetric Evo Ceram, showed more homogenous surface structures compared to GICs and restorative composites. Therefore, wear values of core build-up materials not only differed widely but were higher than those of conventional restorative materials; yet, core build-up materials showed advantageous surface structures.

Penetration of moxifloxacin into rat mandibular bone and soft tissue

Objective. Based on its in vitro activity and spectrum of activity, the new 8-methoxyquinolone antibiotic moxifloxacin (MXF) seems suited for the antibiotic therapy of odontogenic infections. Penetration into the relevant tissue is another prerequisite for clinical efficacy. For this reason, the levels of MXF in plasma, soft tissue, and mandibular bone were determined in an animal model with Wistar rats. Material and methods. Samples of 49 rats were analyzed. Tissue samples were homogenized and proteins were precipitated. The pharmacokinetic evaluation was conducted based on non-compartmental analysis. Results. The concentration-time courses of tissues show a more plateau-shaped curve compared to plasma. Calculated AUC (area under the curve) ratios tissue:plasma were M. masseter:plasma = 2.64 and mandibles:plasma = 1.13. Conclusions. Administration of antibiotics is considered an important part of therapy during and/or after surgical procedures in the maxillofacial area. Because of the good penetration into bone and muscle tissues demonstrated in Wistar rats, MXF might be an option for clinical application in this indication.

Odontogenic infections: an 8-year epidemiologic analysis in a dental emergency outpatient care unit.

Abstract Objectives. The purpose of this investigation was to analyze epidemiological patterns, clinical features and the management of odontogenic infections in patients undergoing treatment in a dental emergency outpatient care unit. Study design. A retrospective analysis of 58 161 case records of patients presenting to an emergency outpatient unit in Hamburg, Germany between 2000–2007 was performed. From this pool, patients with odontogenic infections were identified using an ICD-10 code, analyzing age, gender, medical co-morbidities, duration of pain, ratio of infiltrates/abscesses, affected teeth, management of infection and administered antibiotics. Results. Of the 58 161 patients, 5357 (9.2%) were identified as having odontogenic infections, with 2689 (50.2%) inflammatory infiltrates and 2668 (49.8%) abscesses. Mean age was 34.8 ± 16.8 years. As the primary site of odontogenic infection, the most significantly affected teeth were the maxillary and mandibular first molars. Patients in age-group 20–29 years (25.1%) utilized the emergency care unit more frequently than other age groups. Clindamycin was the most frequently administered antibiotic. Conclusions. Early recognition, diagnosis and management of odontogenic infections are requisite for avoiding or minimizing the development of potential complications. Strategies and evidence-based protocols should be developed within the dental ambulatory care sector, advancing interdisciplinary cooperation between general dentists and oral or maxillofacial surgeons.

Cleaning Effectiveness of Implant Prophylaxis Instruments

PURPOSE The aim of this study was to evaluate the cleaning effectiveness of implant prophylaxis instruments on polished and acid-etched implant surfaces. MATERIALS AND METHODS Biofilm layers of Streptococcus mutans were grown on a total of 80 titanium disks; 40 disks were polished and 40 were acid-etched. Five disks of each surface were cleaned using each of seven implant prophylaxis instruments: (1) manual plastic curette, (2) manual carbon fiber-reinforced plastic (CFRP) curette, (3) sonic-driven prophylaxis brush, (4) rotating rubber cup with prophylaxis paste, (5) sonic-driven polyether ether ketone (PEEK) plastic tip, (6) ultrasonic-driven PEEK plastic tip, and (7) air polishing with amino acid (glycine) powder. Ten disks (five of each surface type) served as controls. After cleaning, the surfaces with remaining bacteria were assessed by light microscopy. Statistical analyses of the results were performed with one-way and two-way analyses of variance with Bonferroni-Dunn multiple comparisons post hoc analysis (α = .05). RESULTS The cleaning effectiveness of the plastic curette was significantly lower than those of all machine-driven instruments on the polished surface. Significantly lower cleaning effectiveness occurred with the CFRP curette compared to the prophylaxis brush and to both oscillating PEEK plastic tips on the polished surface. The rubber cup provided less cleaning effectiveness compared to the ultrasonic PEEK plastic tip and air polishing on the acid-etched surface. Superior results, with less than 4% of the biofilm remaining, were obtained for both oscillating PEEK plastic tips and air polishing on both implant surfaces. The cleaning ability of the prophylaxis brush, rubber cup, and ultrasonic PEEK plastic tip differed significantly between both surface structures. CONCLUSIONS Cleaning effectiveness, ie, less than 4% of the biofilm remaining, was not observed with all tested implant prophylaxis instruments. The cleaning ability of the devices depended on the implant surface structure.

A paradigm shift in mechanical biofilm management? Subgingival air polishing: a new way to improve mechanical biofilm management in the dental practice.

In the past few years indications for the use of the air polishing technology have been expanded from supragingival use (airflow) to subgingival air polishing (perioflow) by the development of new low-abrasive glycine-based powders and devices with a subgingival nozzle. Several studies on the subgingival use of air polishing have been completed. On 7 June 2012, during the Europerio 7 Congress in Vienna, a consensus conference on mechanical biofilm management took place aiming to review the current evidence from the literature on the clinical relevance of the subgingival use of air polishing and to make practical recommendations for the clinician. Bernita Bush (Bern), Prof Johannes Einwag (Stuttgart), Prof Thomas Flemmig (Seattle), Carmen Lanoway (Munich), Prof Ursula Platzer (Hamburg), Prof Petra Schmage (Hamburg), Brigitte Schoeneich (Zurich), Prof Anton Sculean (Bern), Dr Clemens Walter (Basel), and Prof Jan Wennström (Gothenburg) discussed under the moderation of Klaus-Dieter Bastendorf and Christian Becker (both ADIC Association for Dental Infection Control) the available clinical studies to reach a consensus on available clinical evidence. This paper summarizes the main conclusions of the consensus conference and points to the clinical relevance of the findings for the dental practitioner.

Shear bond strengths of five intraoral porcelain repair systems

In fixed prosthodontics, fracture of the porcelain veneer is not an uncommon problem under clinical conditions due to, e.g., malfunction, trauma or technical failures. To avoid time-consuming and cost-intensive renewal of the entire restoration, repair of the chipped veneer is desirable. The aim of this in vitro study was to evaluate the shear bond strengths of five intraoral porcelain repair kits based on different chemical bonding systems. 45 metal plates veneered with feldspathic porcelain were fabricated. The surface treatment was performed using five porcelain repair systems based on tribochemical silica coating (Cojet), mechanical roughening (Silistor, Cimara, Ceramic Repair) or etching (Clearfil Repair) followed by application of silane coupling agents (five specimens each). Cylinders of composite resin of Charisma and Pertac Hybrid were bonded using Cojet, Silistor, Cimara and Ceramic Repair, and of Clearfil AP-X with Clearfil Repair onto the porcelain specimens. After thermocycling (5000 cycles, 5–55°C) shear bond strength was measured according to ISO 10477 followed by assessment of the failure mode. Statistical analysis was carried out with one-way ANOVA and Bonferroni–Dunns multiple comparisons post-hoc analysis for test groups (α = 0.05). Shear bond strengths higher than 10 MPa were found for all test groups except for Ceramic Repair with Pertac Hybrid (8.1 ±1.3 MPa), which was significantly lower than all other groups (P < 0.05). Highest shear bond strength was found for Silistor with Charisma (23.1 ± 5.8 MPa), which was significantly higher (P < 0.05) than all other groups except Cojet with Charisma (17.8 ± 3.6 MPa) and Clearfil Repair (20.3 ± 5.0 MPa). Cojet and Silistor with Charisma, Cimara, as well as with Clearfil mainly showed cohesive or mixed failure modes (cohesive and interfacial). Bond strengths of the combinations Silistor-Charisma, Clearfil Repair-Clearfil AP-X and Cojet-Charisma were superior to all other combinations used in the present tests.

Untersuchungen zur Haftfestigkeit von Brackets mit und ohne Silanisierung

ZusammenfassungZiel der Untersuchung war es, einen neuen Retentionsmechanismus beim Verbund zwischen Adhäsiv und herkömmlichen Bracket-Basistypen zu evaluieren. Für die Untersuchungen wurden fünf verschiedene Metallbracket-Typen ausgewählt, die unterschiedliche Basen aufwiesen. Die glatten Metallbrackets wurden als Kontrollgruppe herangezogen. Je zehn beschichtete und unbeschichtete Prüfkörper von jeder Gruppe wurden mit Concise Enamel Bond auf die Zähne geklebt und nach 28 Tagen die Scherkräfte mit einer Zugprüfmaschine gemessen. Die silanbeschichteten Basen zeigten ein höheres Retentionspotential als die herkömmlichen Basen. Die silanisierten glatten Bracketbasen ließen eine ähnlich gute Haftung zum Adhäsiv erkennen wie die mit zusätzlichen mechanischen Retentionen versehenen, nicht silanisierten Brackets.SummaryThis study was undertaken to show that a silane treated bracket base can provide a better bonding to the enamel than conventional bonding bases commercially available. Five different types of metal brackets, each with different retentive properties, were tested. 20 brackets of each type were used, half of them silanated with a special silicoater treatment. The brackets were bonded to the surface of the teeth with Concise Enamel Bond and were then tested to failure in an Instron testing machine after 28 days. The following conclusions can be drawn from the study: 1. Silane-coated bracket bases demonstrated a higher bonding strength than the conventional bases, 2. silane treatment of plain bases is an effective method for the bonding of brackets to teeth, similiar to non-silane-boated brackets with additional mechanical retentive devices.