Effects of a Lead Chloride Shell on Lead Sulfide Quantum Dots.

The size of a quantum-confined nanocrystal determines the energies of its excitonic transitions. Previous work has correlated the diameters of PbS nanocrystals to their excitonic absorption; however, we observe that PbS quantum dots synthesized in saturated dispersions of PbCl can deviate from the previous 1S-1S energy vs diameter curve by 0.8 nm.

Fabrication of Fully Solution Processed Inorganic Nanocrystal Photovoltaic Devices.

We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal inks. For the photoactive absorber layer, colloidal CdTe and CdSe nanocrystals (3-5 nm) are synthesized using an inert hot injection technique and cleaned with precipitations to remove excess starting reagents. Similarly, gold nanocrystals (3-5 nm) are synthesized under ambient conditions and dissolved in organic solvents.

Comparative three-dimensional analysis of initial biofilm formation on three orthodontic bracket materials.

Introduction: The purpose of the present study was to investigate and compare early biofilm formation on biomaterials, which are being used in contemporary fixed orthodontic treatment.

Methods: This study comprised 10 healthy volunteers (5 females and 5 males) with a mean age of 27.3 +-3.

The Peri-Implant and Periodontal Microbiota in Patients with and without Clinical Signs of Inflammation.

Late implant failures, caused by the inflammation of surrounding tissues are a problem in implant dentistry. The path of bacterial transmission from teeth to implants is not completely understood. Therefore, the purpose of this study was to analyze intraindividual bacterial transmission characterizing subgingival microbiomes in teeth and implants, both in healthy subjects and in those with signs of periodontitis or peri-implantitis.

Reliability and validity of measurements on digital study models and plaster models.

Objective: To compare manual plaster cast and digitized model analysis for accuracy and efficiency.

Material And Methods: Nineteen plaster models of orthodontic patients in permanent dentition were analyzed by two calibrated examiners. Analyses were performed with a diagnostic calliper and computer-assisted analysis after digitization of the plaster models.

Introducing a semi-coated model to investigate antibacterial effects of biocompatible polymers on titanium surfaces.

Peri-implant infections from bacterial biofilms on artificial surfaces are a common threat to all medical implants. They are a handicap for the patient and can lead to implant failure or even life-threatening complications. New implant surfaces have to be developed to reduce biofilm formation and to improve the long-term prognosis of medical implants.

High extinction coefficient Ru-sensitizers that promote hole transfer on nanocrystalline TiO₂.

Two series of Ru(II) polypyridyl compounds with formulas [(bpy)2RuL](PF6)2 and [(deeb)2RuL](PF6)2, where bpy is 2,2'-bipyridine, deeb is 4,4'-diethylester-2,2'-bpy, and L is one of several substituted 9'-(1,3-dithiole-2-ylidene)-4',5'-diazafluorene ligands, were studied as potential photosensitizers for TiO2. These compounds possess notably high extinction coefficients (≥40,000 M(-1) cm(-1) @470 nm) which are shown by time-dependent density functional theory (TD-DFT) calculations to result from overlapping metal-to-ligand charge transfer (MLCT) and ligand-localized transitions. Low-temperature absorption and photoluminescence measurements were suggestive of a short-lived MLCT excited state.

Three-dimensional analysis of initial biofilm formation on polytetrafluoroethylene in the oral cavity.

Aim: There is published evidence that polytetrafluoroethylene (PTFE) exhibits beneficial surface characteristics by means of long-term biofilm accumulation. The purpose of this study was to investigate and compare early biofilm formation on polytetrafluoroethylene, ceramic-reinforced polytetrafluoroethylene and as the control group, stainless steel.

Materials And Methods: This study comprised 10 healthy volunteers (5 females and 5 males) with a mean age of 27.

The oral cavity is not a primary source for implantable pacemaker or cardioverter defibrillator infections.

Background: To test the hypothesis that the oral cavity is a potential source for implantable pacemaker and cardioverter defibrillators infections, the bacterial diversity on explanted rhythm heart management devices was investigated and compared to the oral microbiome.

Methods: A metagenomic approach was used to analyze the bacterial diversity on the surfaces of non-infected and infected pacemakers. The DNA from surfaces swaps of 24 non-infected and 23 infected pacemaker were isolated and subjected to bacterial-specific DNA amplification, single strand conformation polymorphism- (SSCP) and sequencing analysis.

Experimental gingivitis induces systemic inflammatory markers in young healthy individuals: a single-subject interventional study.

Objectives: We here investigated whether experimental gingivitis enhances systemic markers of inflammation which are also known as surrogate markers of atherosclerotic plaque development.

Background: Gingivitis is a low-level oral infection induced by bacterial deposits with a high prevalence within Western populations. A potential link between the more severe oral disease periodontitis and cardiovascular disease has already been shown.

Antimicrobial surface coatings for a permanent percutaneous passage in the concept of osseointegrated extremity prosthesis.

The clinical implementation of percutaneous implants is still limited owing to infections at the side of the stoma. In our concept, this issue is addressed by designing copolymer surface coatings possessing biocompatibility and antimicrobial activity to improve the maintenance of a physiological skin seal at the skin-implant interface. Different copolymers with surface-active phosphonate and antimicrobial cationic groups were designed.

16S rDNA-based metagenomic analysis of human oral plaque microbiota in patients with atherosclerosis and healthy controls.

To address the question if an altered oral microbiota is associated with atherosclerosis. Twenty patients suffering from atherosclerosis and 10 controls were recruited. Clinical oral, medical and laboratory investigations were performed.

New dicarboxylic acid bipyridine ligand for ruthenium polypyridyl sensitization of TiO2.

An ambidentate dicarboxylic acid bipyridine ligand, (4,5-diazafluoren-9-ylidene) malonic acid (dfm), was synthesized for coordination to Ru(II) and mesoporous nanocrystalline (anatase) TiO(2) thin films. The dfm ligand provides a conjugated pathway from the pyridyl rings to the carbonyl carbons of the carboxylic acid groups. X-ray crystal structures of [Ru(bpy)(2)(dfm)]Cl(2) and the corresponding diethyl ester compound, [Ru(bpy)(2)(defm)](PF(6))(2), were obtained.

The Effectiveness of Poly-(4-vinyl-N-hexylpyridiniumbromide) as an Antibacterial Implant Coating: An In Vitro Study.

The clinical success of osseointegrated dental implants depends on the strong attachment of the surrounding hard and soft tissues. Bacterial adhesion on implant surfaces can cause inflammatory reactions and may influence healing and long-term success of dental implants. Promising implant coatings should minimize bacterial adhesion, but allow epithelial and connective tissue attachment.

Comparative analysis of biofilm formation on dental implant abutments with respect to supra- and subgingival areas: polytetrafluoroethylene versus titanium.

The aim of the present in vivo study was to examine the effect of polytetrafluoroethylene (PTFE) surfaces on biofilm formation on dental implant abutments in comparison to titanium surfaces. Fifteen modified abutments with incorporated PTFE plates were inserted in 10 patients for 14 days. Scanning electron microscopy techniques were used to examine biofilm formation on different surfaces and to determine the percentage of surface coverage.

Comparative analysis of long-term biofilm formation on metal and ceramic brackets.

Objective: To test the null hypothesis that stainless steel and ceramic brackets show no differences in biofilm adhesion.

Materials And Methods: Twenty adolescents (6 boys, 14 girls) who had received fixed orthodontic therapy for 18.9 ± 3.

Metagenomic analysis of the peri-implant and periodontal microflora in patients with clinical signs of gingivitis or mucositis.

The long-term success of osseointegrated oral implants is endangered by inflammation of peri-implant hard and soft tissues caused by bacterial biofilms that may have been initiated by bacterial transmission from the adjacent dentition. The present study aimed to compare the bacterial communities at inflamed implant and tooth sites by broad-range PCR techniques to evaluate the etiological processes of peri-implant and periodontal diseases and potential future therapeutic strategies. Eighteen samples of peri-implant and periodontal microflora were collected from nine partially edentulous patients with implant-retained crowns or bridges revealing clinical signs of gingivitis or mucositis.

Microbial diversity of peri-implant biofilms on implant fixed bar and telescopic double crown attachments.

One of the principal problems in oral implantation is inflammation of peri-implant hard and soft tissues caused by bacterial biofilms. The purpose of the present study was to evaluate the microbial diversity of peri-implant biofilms on 2 different implant-anchored attachment types in vivo. Samples of peri-implant sulcus fluid were collected from 8 patients with implant-supported bar attachments and 8 patients with implant-anchored telescopic double crown attachments.

Microbial diversity of supra- and subgingival biofilms on freshly colonized titanium implant abutments in the human mouth.

Supra- and subgingival biofilm formation is considered to be mainly responsible for early implant failure caused by inflammations of periimplant tissues. Nevertheless, little is known about the complex microbial diversity and interindividual similarities around dental implants. An atraumatic assessment was made of the diversity of microbial communities around titanium implants by single strand conformation polymorphism (SSCP) analysis of the 16S rRNA gene amplicons as well as subsequent sequence analysis.

Prevention of early vascular graft infection using regional antibiotic release.

Background: Infections after prosthetic replacement of the aorta remain a serious and life-threatening complication. The only appropriate treatment is the surgical removal of the infected prosthesis. Accordingly, there is a need for new procedures to prevent the infection of vascular prostheses.

Influence of preliminary damage on the load-bearing capacity of zirconia fixed dental prostheses.

Purpose: The objective of this investigation was to evaluate the influence of differently shaped preliminary cuts in combination with artificial aging on the load-bearing capacity of four-unit zirconia fixed dental prostheses (FDPs).

Materials And Methods: Forty frameworks were fabricated from white-stage zirconia blanks (InCeram YZ, Vita) by means of a computer-aided design/computer-aided manufacturing system (Cerec inLab, Sirona). Frameworks were divided into four homogeneous groups with ten specimens each.

Reaction of Ru(II) diazafluorenone compound with nanocrystalline TiO2 thin film.

The Ru(II) compounds [Ru(bpy)(2)(mcbH)](2+) and [Ru(bpy)(2)(dafo)](2+), bpy is 2,2'-bipyridine where mcbH is 3-(CO(2)H)-2,2'-bipyridine and dafo is 4,5-diazafluoren-9-one, were synthesized, characterized, and anchored to nanocrystalline mesoporous TiO(2) thin films for excited state and interfacial electron transfer studies. X-ray crystallographic studies of [Ru(bpy)(2)(mcbH)](PF(6))(Cl) revealed a long Ru-N distance to the unsubstituted pyridine ligand of mcbH. Reaction of [Ru(bpy)(2)(dafo)](2+) with TiO(2) thin films resulted in interfacial chemistry.

Reduction of biofilm on orthodontic brackets with the use of a polytetrafluoroethylene coating.

Treatment with fixed orthodontic appliances can cause enamel demineralization by increased biofilm adhesion. The purpose of the present study was to investigate whether a polytetrafluoroethylene (PTFE) coating reduces biofilm formation on orthodontic brackets. One PTFE-coated bracket and one uncoated stainless steel bracket were bonded symmetrically on the first or second (four maxillary and nine mandibular) primary molars in 13 adolescent patients (five females and eight males, aged 11.

Short-term influence of lingual orthodontic therapy on microbial parameters and periodontal status. A preliminary study.

Objective: To perform a preliminary study of the short-term effect of fixed, customized lingual orthodontic appliances on periodontal and microbial parameters.

Materials And Methods: The sample comprised 20 subjects (6 males and 14 females) with a mean age of 22.3 years +/- 8.