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Previous epidemiological studies regarding the association between chronic periodontitis (CP) and carotid intima-media thickness (cIMT) and subclinical atherosclerosis have been inconclusive.The aim of this study was to determine whether CP is associated with subclinical atherosclerosis in a large population-based cohort study conducted in northern Germany (the Hamburg City Health study).Baseline data from 5781 participants of the Hamburg City Health Study with complete oral health and carotid ultrasound data (50.7% female, mean age: 62.1 ± 8.4 years) were evaluated. A standardized duplex sonography of the carotid artery was performed with measurement of carotid intima-media thickness (cIMT) and atherosclerotic plaques. Oral health was assessed by recording the decayed, missing, and filled teeth (DMFT) index, clinical attachment loss (CAL), bleeding on probing (BOP), and the dental plaque index (PI). Correlations were tested for statistical significance by means of descriptive statistics and multivariate regression analyses.Moderate and severe CP were associated with the prevalence of cIMT ≥ 1 mm (none or mild CP: 5.1%, moderate CP: 6.1%, severe CP: 10%) and mean cIMT (none or mild CP: 0.72 mm, moderate CP: 0.75 mm, severe CP: 0.78 mm) in bivariate analyses (p .001). Additionally, severe and moderate CP were associated with higher prevalence of carotid atherosclerotic plaques (plaque = yes: none or mild CP: 23.9%, moderate CP: 29%, severe CP: 40.2%,). After adjustment for age, sex, smoking, diabetes, hypertension, educational level, hypercholesterolemia, and hsCRP, severe CP still correlated significantly with cIMT and the prevalence of cIMT ≥1 mm and/or presence of carotid atherosclerotic plaques.In this study, severe CP was associated with increased cIMT and higher prevalence of carotid plaques independent of common risk factors.

Background Although DNA of high quality can be easily prepared from cultured cells with commercially available kits, many studies involve a large number of samples which increases the cost drastically. We optimized two simple and inexpensive methods for preparing DNA suitable for digital PCR from a small number of cells directly from wells of 96‐well plates. Methods Cells (number: 103‐104) were lysed with a Direct PCR® lysis buffer or a 10% Chelex100® solution. The lysates were further purified and concentrated by means of DNA precipitation with a blue‐colored glycogen as a carrier. PCR and digital PCR were used to evaluate the efficiency of the two methods. Results For 1000 cells from one primary culture and two tumor cell lines, DNA was reproducible and obtained with recovery rate (obtained/expected amount of DNA) in the range of 50%‐90% as measured by the fluorometer dyes instrument Qubit. Using 8 out of a total of 10 µL DNA solution for 1000 cells, both conventional PCR and digital PCR were successful. For digital PCR, more than 1600 positive droplets were obtained for DNA from 1000 cells using the Direct PCR® method, corresponding to a yield efficiency of approximately 80%. Further reducing the number of cells down to 100 would be possible with 160 positive droplets expected. Both reagents are inexpensive (0.08€/sample). Conclusions Two methods are efficient, especially the Direct PCR® reagent‐based method provides a simple and inexpensive method for preparing DNA suitable for digital PCR from small number of cells., With commercially available kits, DNA of high quality can be easily prepared from cultured cells. However, many studies involve a large number of samples which increases the cost drastically. In addition, a limited amount of each sample often is also a challenge. We optimized two simple and inexpensive methods for preparing DNA suitable for digital PCR from a small number of cells directly from wells of 96‐well plates. Using 8 out of the total of 10µl DNA solution for 1000 cells, both conventional PCR and digital PCR were successful. For digital PCR, more than 1600 positive droplets were obtained for DNA from 1000 cells using the Direct PCR® method, corresponding to a yield efficiency of approximately 80%.

With the emerging development and improvement of biomaterials, the application of ceramics in restorative medicine has experienced a renaissance. New production processes have reportedly helped to overcome unfavorable biomechanical characteristics of these materials, which lead to a wide application of zirconia as ground material for dental implants. Zirconia-based implants are biocompatible, demonstrate ability to osseointegrate and have a teeth-like color, rendering them to be an ideal replacement for titanium-based implant systems, which represent the current gold standard in implantology. However, there is a lack of standardized guidelines on production of zirconia-based implants and long-term studies on the stability of this material in vivo are missing. In this study we demonstrate for the first time the accumulation of degradation products of a commercially available one-piece zirconia-based dental implant 29 months after implantation, which was recovered following a traumatic accident. Biopsy specimens from the implant and the surrounding tissue attached to it were processed for histological and histomorphometrical analysis. Although the implant was well integrated into the anchoring bone, degradation particles were observed in tissues adjacent to lower aspects of the implant. The observed implant degradation might seriously compromise implant stability several years after implantation. This incidental finding highlights the requirement of further research on zirconia-based ceramics before they can be advertised as safe alternative to titanium-based implant systems. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2919-2923, 2018.

This study assesses the biocompatibility of novel silk protein membranes with and without modification, and evaluates their effect on facilitating bone formation and defect repair in guided bone regeneration. Two calvarian bone defects 12 mm in diameter were created in each of a total of 38 rabbits. Four different types of membranes, (silk-, hydroxyapatite-modified silk-, β-TCP-modified silk- and commonly clinically used collagen-membranes) were implanted to cover one of the two defects in each animal. Histologic analysis did not show any adverse tissue reactions in any of the defect sites indicating good biocompatibility of all silk protein membranes. Histomorphometric and histologic evaluation revealed that collagen and β-TCP modified silk membranes supported bone formation (collagen: bone area fraction p = 0.025; significant; β-TCP modified silk membranes bone area fraction: p = 0.24, not significant), guided bone regeneration and defect bridging. The bone, which had formed in defects covered by β-TCP modified silk membranes, displayed a more advanced stage of bone tissue maturation with restoration of the original calvarial bone microarchitecture when compared to the bone which had formed in defects, for which any of the other test membranes were used. Micro-CT analysis did not reveal any differences in the amount of bone formation between defects with and without membranes. In contrast to the collagen membranes, β-TCP modified silk membranes were visible in all cases and may therefore be advantageous for further supporting bone formation beyond 10 weeks and preventing soft tissue ingrowth from the periphery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

The osseointegration of bone implants, implant failure, and the bridging of critical-size bone defects are frequent clinical challenges. Deficiencies in endogenous bone healing can be resolved through the local administration of suitable recombinant growth factors (GFs). In preclinical models, gene-therapy-supported bone healing has proven promising for overcoming certain limitations of GFs. We report the dose-dependent bridging of critical-size mandibular bone defects (CSDs) in a rat model using a non-viral BMP-2-encoding copolymer-protected gene vector (pBMP-2) embedded in poly(d, l-lactide) (PDLLA) coatings on titanium discs that were used to cover drill holes in the mandibles of 53 male Sprague Dawley rats. After sacrificing, the mandibles were subjected to micro-computed tomography (µCT), micro-radiography, histology, and fluorescence analyses to evaluate bone regeneration. pBMP-2 in PDLLA-coated titanium implants promoted partial bridging of bone defects within 14 days and complete defect healing within 112 days when the DNA dose per implant did not exceed 2.5 µg. No bridging was observed in untreated control CSDs. Thus, the delivery of plasmid DNA coding for BMP-2 appears to be a potent method for controlled new-bone formation with an inverse dose dependency. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2441-2455, 2016.

Patients' perspective is increasingly re-cognised as an important outcome measure in oral surgery. However, how patients perceive the surgical treatment cannot be assessed currently. This would be an important indicator for process-related quality of care. It was the aim to develop and to validate an instrument for the assessment of patient-based measures of process-related quality of care in oral surgery. The new Burdens in Oral Surgery Questionnaire (BiOS-Q) was developed in two steps in patients undergoing oral surgery. First, an item pool was created using semi-structured interviews in 90 patients. Second, a preliminary version was applied in 297 consecutively recruited patients to assess redundancy, completion rates, face validity, difficulty and distribution. Psychometric properties of the final version of the questionnaire were evaluated. The BiOS-Q consists of 16 items and showed satisfactory internal consistency (Cronbach's alpha = 0·84) and excellent test-retest reliability (ICC = 0·90). The questionnaire's mean score was significantly correlated with dentists' burdens (r = 0·44) and patients' overall satisfaction (r = 0·39) indicating sufficient validity. The BiOS-Q is a reliable and valid instrument for the assessment of patient-based process-related quality of care in oral surgery.

This study evaluates a novel adhesive fixation technique to affix cortical bone fragments to osteosynthesis plates using common PMMA cement. This technique utilizes a new amphiphilic bone bonding agent adhering with both hydrophilic bone and hydrophobic PMMA cement. After in vitro biomechanical testing of the bonding strength with explanted bovine and rabbit calvarian bone samples, osteosynthesis plates with screw holes of 1.3 and 1.5 mm were placed on the cranial bone of New Zealand white rabbits and the bond strength of these plates was determined through tension tests. In vitro bond strengths of 19.8-26.5 MPa were obtained. Control samples, prepared without a bone bonding agent, exhibited bone bonding strengths

The aim of this study was to evaluate the impact of clinical periodontal parameters and the presence of periodontal pathogens in patients with acute myocardial infarction (AMI).A total of 104 subjects (54 patients with AMI and 50 healthy controls) were included. Subgingival plaque samples were analyzed for periodontal pathogens Aggregatibacter actinomycetemcomitans (Aa; previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf; previously T. forsythensis), and Prevotella intermedia (Pi) using dot-blot hybridization.Patients with AMI had a significantly higher frequency of probing depths (PDs)or=4 mm than controls (39.2% versus 14.9%; P0.0001). Among different cutoff levels, the frequency of50% sites with PDsor=4 mm showed the highest discrepancy between both groups (33% versus 0%; P0.001). All periodontal pathogens were overrepresented in patients with AMI and positively correlated with increased periodontal PD and clinical attachment level (CAL). After adjustment for age, gender, smoking, body mass index, hypertension, plaque index, statin intake, and ratio of cholesterol to high-density lipoprotein, Pg remained a significant predictor for AMI (odds ratio [OR]: 13.6; 95% confidence interval [CI]: 3.1 to 59.8; P = 0.0005). Furthermore, the simultaneous presence of Aa + Pg (P = 0.0005) and Aa + Pg + Tf (P = 0.0018) were found with significantly higher frequency in patients with AMI than controls.The results of our study confirm an association between periodontitis and AMI in which periodontal destruction was correlated with the presence of periodontal pathogens. In particular, Pg might be considered a potential risk indicator for AMI.

Recent data indicate that interleukin (IL)-1 polymorphism may influence the susceptibility to periodontitis and coronary heart diseases. The aim of this study was to evaluate the impact of the composite IL-1 genotype (allele 2 at IL-1A -889 and IL-1B +3954) in the association between acute myocardial infarction (AMI) and periodontitis.One hundred four white subjects (54 patients with AMI and 50 healthy controls) were studied; each received a comprehensive periodontal examination, including measurement of periodontal probing depth (PD) and clinical attachment level (CAL). The extent of periodontitis was assessed by the percentage of sites with clinical AL3 mm. Polymorphisms in the IL-1 gene cluster were assessed using a reverse hybridization assay.Compared to controls, mean values for PD (4.6 mm versus 3.7 mm; P0.0001) and CAL (5.4 mm versus 4.5 mm; P = 0.0001) were significantly increased among patients with AMI. Significantly more subjects with moderate or severe periodontitis (or =33% of sites with clinical AL3 mm) were found in the AMI group compared to controls (31.5% versus 8%; P = 0.0016). These differences remained statistically significant after adjustment for smoking, age, and gender. No significant differences were observed in the allele frequencies of the gene loci IL-1A -889 and IL-1B +C3954 between patients with AMI and controls. Also, there was no difference in the frequency of the composite IL-1 genotype. IL-1 genotype-positive patients with AMI had slightly increased PD and AL compared to IL-1 genotype-negative patients with AMI.The results confirmed an association between periodontitis and AMI but failed to detect a modifying impact of the composite IL-1 genotype. Although the IL-1 genotype was only weakly associated with compromised periodontal health, it was not associated with AMI.

Methods of therapeutic apheresis, such as plasma exchange or rheopheresis eliminate moderately aggregating macromolecules like fibrinogen, as well as strongly aggregating substances like alpha2-macroglobulin from blood. In order to examine the specific effect of eliminating alpha2-macroglobulin as a highly aggregating macromolecule, this study aimed to analyze the different rheological properties of: (i) moderately aggregating red blood cells (RBCs; inducible by fibrinogen); and (ii) strongly aggregating RBCs (inducible by alpha2-macroglobulin). In vitro, RBC aggregate geometry was determined in the presence of strong and moderate aggregation inducing macromolecules. In vivo, flow behavior of RBC aggregates was analyzed by intravital microscopy. Using network scanning, the number of perfused and non-perfused microvessels was determined. In vitro, the higher adhesive forces of strongly aggregating RBCs led to both a higher packing density of single RBCs within aggregates, expressed as a significantly reduced thickness of individual RBCs, and greater deformation, expressed as a significantly diminished offset between RBCs and an increased curvature of RBCs at the ends of the aggregates. In vivo rheoscopy showed that only high aggregating RBCs persisted in the precapillary bed and led to the absence of RBCs in up to 40% of nutritive capillaries. These novel findings are of importance regarding recent developments in clinical hemorheology, specifically the clinical use of hemapheretic therapies for diseases in which impaired microcirculation plays a role in either their development or progression, such as age-related macular degeneration and complications of diabetes mellitus. Our data support that procedures reducing the concentration of alpha2-macroglobulin in blood by extracorporeal elimination might provide a more efficient improvement of overall blood fluidity in microcirculatory beds.

For the prognosis and long-term stability of an implant, for example a hip- or knee-implant, the anchorage to the bone is of critical importance. Normally for this anchorage bone cement is used, which achieves sufficient retention to spongious bone structure. If there is the need for osteosynthesis of midfacial fractures for surgical therapy, in some situations it would be clinically preferable to fix the reconstruction plates without the usual system using screws. This is the aim of the new adhesive fixing technology which is presented in this article. The structure of bone in midface, however, is cortical and such a smooth surface will allow only insufficient retention forces between bone and bone cement. In order to obtain a good adhesion at cortical bone nevertheless, we have to apply a bone bonding agent similar to techniques used in dentistry, which are based on dentin bonding agents, because there are different wetting properties of the hydrophilic bone and the hydrophobic bone cement monomers. Determination of achievable bond strength was done in a tension test ex vivo. Reconstruction plates were fixed with bone cement at bovine bone conditioned with a bone bonding agent developed for this field of application. With bond strengths up to 6 MPa it is assumed that an adhesive fixation of reconstruction plates at cortical bone structure is possible using the developed amphiphilic bone bonding agent. Partielle adhasive Fixation von Osteosynthesplatten bei Mittelgesichtsfrakturen – eine alternative Losung zur Verschraubung? Fur die Prognose und Langzeitstabilitat einer Implantation, beispielsweise einer Huft- oder Knieendoprothese, ist die Verankerung des Implantats am Knochen von entscheidender Bedeutung. Fur diese Verankerung hat sich Knochenzement bewahrt, der jedoch vorzugsweise eine gute Retention zu spongiosem Knochen herstellt. Bei der Anwendung von Osteosynthesematerial im Schadelbereich, als chirurgische Therapiemasnahme einer Mittelgesichtsfraktur, ware es klinisch wunschenswert, dunne Knochenfragmente oder Knochensplitter an den Osteosyntheseplatten zu verankern, ohne hierbei die ubliche Fixation durch Verschraubung anzuwenden. Dies kann durch die von uns vorgestellte neuartige adhasive Befestigungstechnik erreicht werden. Dazu ist es unabdingbar, am kortikalen Deckknochen des Schadelbereichs eine ausreichende Haftung von Knochenzement oder anderen korpervertraglichen Zementen herzustellen. Analog zu den schon seit langem in der klinischen Anwendung befindlichen Dentinhaftvermittlern der Zahnheilkunde wird eine amphiphile Zwischenschicht zur Optimierung der Anbindung des hydrophoben Knochenzements an den hydrophilen Knochen als Knochenhaftvermittler vorgeschlagen. Die Bestimmung der erreichbaren Haftfestigkeiten erfolgte ex vivo im Zugversuch. Dazu wurden die Osteosyntheseplatten mit einem Knochenzement an frischen, mit dem entwickelten Knochenhaftvermittler konditionierten Rinderknochenproben fixiert. Mit den gemessenen Haftfestigkeiten von bis zu 6 MPa sollte eine adhasive Fixation der Osteosyntheseplatten an kortikalen Knochen durch die Konditionierung des Knochens mit einem amphiphilen Knochenhaftvermittler moglich werden.