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Purpose To evaluate the residual surface roughness of 5 common diamond-coated interproximal reduction (IPR) systems after consecutive in vitro applications in relation to system, diamond grain size, and instrument thickness. Methods IPR was performed on 80 extracted human incisors using motor-driven strips and discs under predefined conditions. The IPR auxiliaries were applied at 5 consecutive sessions of 20 s on intact interproximal surfaces, and the surface profile (Ra, Rz, Rmax) was analyzed at baseline and after each session with an optical profilometer. Results No overall significant difference in the roughness values was found between systems (P = 0.07 for Ra, P = 0.33 for Rz, and P = 0.48 for Rmax). There was a significant average decrease of Ra, Rz, and Rmax for all systems for every unit increase in time by −0.171 μm (P P ≤ 0.001), and −2.788 μm (P = 0.001), respectively. Ra, Rz, and Rmax values increased significantly, i.e., by 0.194 μm (P = 0.003), 5.890 μm (P = 0.001), and 5.319 μm (P = 0.010) as instrument thickness increased by one unit. No significant reductions in Ra, Rz, and Rmax were observed across grain sizes (−0.008 μm [P > 0.05], −0.244 μm [P > 0.05], and −0.179 μm [P > 0.05], respectively). There was no evidence of interaction between system and time as the P values for Ra, Rz, and Rmax were 0.88, 0.51, and 0.70, respectively. Conclusions All IPR materials presented significant gradual decrease of surface roughness after repeated applications. There were no significant roughness changes among auxiliaries of different grain sizes. Thinner auxiliaries showed significantly more roughness reduction, possibly requiring more frequent replacement than thick auxiliaries in clinical practice.

Für den Kliniker ist die Scherhaftfestigkeit eines Adhäsivs ein wichtiger Parameter, da ein ungewollter vorzeitiger Bracketverlust in der Praxis ein unerwünschtes nicht planbares Ereignis ist. Andererseits darf es beim Entfernen von Brackets nicht zu Schmelzausrissen kommen. Es wird angenommen, dass unterschiedliche Ätzmodi sich auf die Scherhaftfestigkeit auswirken. DIN 13990-1/-2 soll die Scherhaftfestigkeit von kieferorthopädischen Adhäsiven einheitlich und reproduzierbar testen. Die Ziele der vorliegenden Studie waren: 1\. die Praktikabilität von DIN 13990-1/-2 für den Anwender zu untersuchen 2\. die Scherhaftfestigkeit der Adhäsive Transbond XT, Beauty Ortho Bond und Fuji Ortho LC unter unterschiedlichen Ätzbedingungen zu bestimmen Methode Die Schmelzoberfläche wurde im ersten Versuchsteil nach Herstellerangaben konditioniert. Im zweiten Versuchsteil wurde die Scherhaftfestigkeit nach zusätzlichem Ätzen oder nach Verwendung eines aggressiveren Ätzmittels bestimmt. Die Studie umfasste 600 Versuche. Dafür wurden 480 bovine bleibende Schneidezähne und 120 Brackets eingebettet. Jedes Adhäsiv wurde im Einzelverbund Schmelz-Adhäsiv, Adhäsiv-Bracket (DIN 13990-1) und im Gesamtverbund Schmelz-Adhäsiv-Bracket (DIN 13990-2) untersucht. Das Abscheren der Brackets bzw. Prüfkörper erfolgte nach Lagerung für 15 min, 24 h und 24 h mit anschließendem Thermocycling. Jeweils 10 Proben wurden hinsichtlich Adhäsiv, Verbundsituation, Konditionierungsmodus und Lagerung gleich behandelt. Die Brackets bzw. Prüfkörper wurden in einer Universalprüfmaschine (Zwick Z010, Ulm) bei einer Traversengeschwindigkeit von 1 mm/min in okklusogingivaler Richtung abgeschert. Anschließend wurde mit 10-facher Vergrößerung die Bruchfläche bewertet und das Frakturmuster bestimmt. Die statistische Auswertung und grafische Darstellung der Scherversuche erfolgte mit Hilfe des Statistikprogramms SPSS für Windows (Version 19.0). Die einfaktorielle ANOVA wurde unter Berücksichtigung der Einflussfaktoren Adhäsiv, Verbundsituation, Konditionierungsmodus und Lagerung angewendet. Zudem wurden t-Tests für unabhängige Stichproben durchgeführt. Ergebnisse • Die Prüfung der Scherhaftfestigkeit nach DIN 13990-1/-2 ist ein praktikables Verfahren, das reproduzierbare Ergebnisse liefert. • Die Scherhaftfestigkeiten der Adhäsive sind in absteigender Reihenfolge am höchsten bei Transbond XT, Beauty Ortho Bond, Fuji Ortho LC. • 500 Zyklen Thermocycling bewirken bei den untersuchten Produkten keinen signifikanten Unterschied der Scherhaftfestigkeit. • Aggressiveres Konditionieren führt zu signifikant höheren Scherhaftfestigkeiten als Konditionieren nach Herstellerangaben. • Die Wahl des Adhäsivs wirkt sich auf die Anzahl der Schmelzausrisse aus. Die meisten Schmelzausrisse traten bei Transbond XT auf. Bei Fuji Ortho LC waren zwei Schmelzausrisse zu verzeichnen. Beauty Ortho Bond ließ keinerlei Schmelzausrisse erkennen. Schlussfolgerung Die in dieser Studie untersuchten Adhäsive Transbond XT und Beauty Ortho Bond eignen sich für den klinischen Einsatz. Fuji Ortho LC erfüllte nicht in allen Versuchskonstellationen die – willkürlich festgesetzten – Minimalanforderungen., High bond strength is desirable; however, enamel damage during debonding must be avoided. At the same time premature loss of brackets during orthodontic treatment is undesirable. Therefore, adhesive bond strength is an important parameter for clinicians. Different types of enamel conditioning are supposed to affect bond strength. DIN 13990-1/-2 describes standardized tests intended to ensure comparability of results. The aims of this study were: 1\. to get information about the suitability of DIN 13990-1/-2 and its recommendations 2\. to test the bond strength of the adhesives Transbond XT, Beauty Ortho Bond and Fuji Ortho LC with various conditioning regimes Material and Methods In the first part of the study the enamel surface conditioning was performed as recommended by the manufacturers. In the second part of the study shear bond strength was tested after additional conditioning or after using a stronger etching substance. A total of 600 experiments were carried out, with groups of 10 specimens each subjected to identical treatments. Shear bond strengths of all adhesives were evaluated separately at the bracket-adhesive and adhesive- enamel interface (DIN 13990-1), as well as at the total (enamel-adhesive- bracket) interface (DIN 13990-2). Shear bond strength (SBS) was tested after storage for 15 min, after storage in distilled water at 37 °C for 24 h and after 24 h followed by thermocycling. After storage, the bonded specimens were tested for SBS using a universal testing machine (Zwick Z010; Ulm, Germany) at a crosshead speed of 1 mm/min in occluso-gingival direction. After debonding the fracture pattern was determined using an optical microscope at 10x magnification and the failure pattern was assessed. Statistical software (SPSS, v.19.0; IBM, Armonk, NY, USA) was used for analysis and graphical presentation of the shear experiments. Analysis of variance (ANOVA) was performed. Consideration was given to the different adhesives, enamel conditioning, interface types and storage modes. T-tests for independent samples were used. Results • DIN 13990-1/-2 is suitable to test shear bond strength. Results are reproducible. • The highest shear bond strengths were measured with Transbond XT, followed by Beauty Ortho Bond and Fuji Ortho LC. • 500 cycles thermocycling did not have a significant influence on the adhesives tested. • Shear bond strength after stronger etching than recommended by the manufacturer led to significantly higher shear bond strengths. • Most enamel damages occurred with Transbond XT. Conclusion Transbond XT and Beauty Ortho Bond are suitable adhesives for clinical needs. Fuji Ortho LC does not meet our (arbitrarily defined) minimum requirements.

The purpose of this work was to analyze the shear bond strength (SBS) of different adhesives for orthodontic brackets in accordance with DIN 13990-1/-2, also taking into consideration potential effects arising from different scenarios of enamel conditioning and specimen storage. A total of 390 experiments were performed, with groups of 10 specimens subjected to identical treatments. Three adhesives were tested: Transbond™ XT (3M Unitek, Monrovia, USA), Beauty Ortho Bond (Shofu, Kyoto, Japan), and Fuji Ortho LC (GC Europe, Leuven, Belgium). SBS was evaluated separately at the bracket–adhesive and adhesive–enamel interfaces, as well as the total (enamel–adhesive–bracket) interface. The brackets were metal brackets for upper right central incisors (Discovery® from Dentaurum, Ispringen, Germany). A universal testing machine (Zwick Z010, Ulm, Germany) was used for testing the SBS after 15 min, or after storage in distilled water at 37 °C for 24 h, or after 24 h followed by 500 thermocycles alternating between 5 and 55 °C. Transbond™ XT produced the highest levels of SBS. The least favorable performance was observed with Fuji Ortho LC after enamel conditioning with 10 % polyacrylic acid. Thermocycling did not have a significant influence. Transbond™ XT and Beauty Ortho Bond (but not Fuji Ortho LC) yielded levels of SBS adequate for clinical application (≥ 7 MPa).

Einleitung Implantatassoziierte Infektionen sind gefürchtete Komplikationen in der Chirurgie des Bewegungsapparates. Staphylococcus aureus ist hierbei der am häufigsten isolierte Erreger. Neben einer zumeist zeit- und kostenintensiven Behandlung ergeben sich für die betroffenen Patienten häufig gravierende sozioökonomische Folgen. Art und Oberflächenbeschaffenheit von Biomaterialien haben einen Einfluss auf die Pathogenese dieser Infektionen. Die Modifikation von Implantatoberflächen kann somit einen Beitrag in der Prophylaxe implantatassoziierter Infektionen leisten. Ziel dieser experimentellen In- vitro-Studie war es, die Adhäsion von Staphylococcus aureus auf biodegradierbaren und antibiotikahaltigen Poly(D,L-Laktid)-Beschichtungen (PDLLA) von Titanplättchen zu untersuchen. Methodik Folgende Modifikationen der Titanplättchen wurden untersucht: I. pures Titan II. PDLLA-Beschichtung III. PDLLA+10 % Gentamicin-Beschichtung IV. PDLLA+10 % Gentamicin-Beschichtung und extra PDLLA-Überzug Die unterschiedlich beschichteten Plättchen wurden in einer Staphylococcus aureus- Bakteriensuspension über einen Zeitraum von insgesamt 24 h inkubiert. Nach 1 h, 6 h, 12 h und 24 h wurden die Plättchen hinsichtlich ihrer bakteriellen Besiedelung mikrobiologisch und fluoreszenzmikroskopisch untersucht. Zusätzlich wurden nach einer Inkubationszeit von 1 h und 12 h rasterelektronenmikroskopische Untersuchungen durchgeführt. Ergebnisse Nach der mikrobiologischen Auswertung wiesen die Plättchen mit PDLLA+10 % Gentamicin zu allen untersuchten Zeitpunkten im Vergleich zu den antibiotikafreien Plättchen signifikant geringere Keimanhaftungen auf. Nach einer Inkubationszeit von 6 h erwiesen sich diese Plättchen nach der mikrobiologischen Analyse sogar als steril. Die Plättchen mit Gentamicin und Extrapolymerschicht zeigten ebenfalls nach 1 h Inkubation eine Inhibition der Bakterienadhäsion. Im Verlauf nahm die Bakterienadhäsion jedoch im Vergleich zur PDLLA+10 % Gentamicin-Gruppe stärker zu. Die wirkstofffreie Beschichtung mit dem Trägermaterial PDLLA hatte keinen signifikanten Einfluss auf die bakterielle Anhaftung. Fluoreszenz- und rasterelektronenmikroskopisch bestätigte sich die Wirkung des Gentamicins auf den Plättchen der PDLLA+10 % Gentamicin-Gruppe. Innerhalb der ersten 12 h Inkubation war das Keimwachstum auf den unbeschichteten Titanplättchen deutlich größer als auf den mit PDLLA+10 % Gentamicin beschichteten Plättchen. Vereinzelt war erkennbar, dass die Bakterien von einer Substanz bedeckt waren. Hierbei handelt es sich möglicherweise um das morphologische Korrelat des Biofilms. Schlussfolgerung Durch eine antibiotikahaltige Beschichtung von Titanplättchen konnte innerhalb der ersten 12 h in vitro eine deutliche Reduktion der Keimzahl auf den Implantatoberflächen nachgewiesen werden. Das könnte der entscheidende zeitliche Vorsprung sein, den die körpereigenen Zellen benötigen, um das „race for the surface“ gegen die Bakterien zu gewinnen., Introduction Implant associated infections are feared complications in orthopedic and trauma surgery. Staphylococcus aureus is the most frequent isolated pathogen. Next to an expensive long-term treatment also the social economic factors have to be taken into account. Nature and surface character of biomaterials influence the pathogenesis of an infection. Therefore the modification of implant surfaces can contribute to the prophylaxis of implant associated infections. The aim of this experimental in-vitro-study was to examine the effects of biodegradable and antibiotic-containing poly(D,L-lactide) coatings (PDLLA) of titanium implants on the adhesion of Staphylococcus aureus. Methods The following modifications of titanium implants were tested: I. pure titanium II. PDLLA-coating III. PDLLA+10 % gentamicin-coating IV. PDLLA+10 % gentamicin-coating and additional PDLLA- coating The different implants were incubated in a bacterial suspension with Staphylococcus aureus over a timespan of 24 h. After 1 h, 6 h, 12 h and 24 h the implants were examined microbiological as well as with a fluorescence microscope in regard to the bacterial colonisation. Additionally they were also examined with a scanning electron microscope after an incubation time of 1 h and 12 h. Results In the microbiological evaluation the PDLLA+10 % gentamicin coated implants showed in comparison to the groups without antibiotics at all incubation times a significant lower rate of bacterial colonisation. After the incubation time of 6 h the microbiological evaluation showed that these implants were even sterile. The implants coated with gentamicin and the additional polymer layer also showed after 1 h of incubation an inhibition of bacterial adhesion. But over the course of time the bacterial adhesion showed a stronger increase compared to the PDLLA+10 % gentamicin- group. The agent free PDLLA coating had no significant effect on the bacterial adhesion. The effect of gentamicin on implants of the PDLLA+10 % gentamicin-group was confirmed by fluorescence and scanning electron microscope. Within the first 12 h of incubation the bacterial growth was clearly higher on the uncoated implants than on the PDLLA+ 10% gentamicin coated implants. In patches bacteria were covered in a substance, possibly the morphological correlate of the biofilm. Conclusion Within the first 12 h the antibiotic coating of titanium implants reduced in vitro the bacterial adhesion on the implant surfaces. This could be the essential temporal advantage for the cells in the human body to win the „race for the surface” against the bacteria.

AIM It is unknown how the heart distinguishes various overloads, such as exercise or hypertension, causing either physiological or pathological hypertrophy. We hypothesize that alpha-calcitonin-gene-related peptide (αCGRP), known to be released from contracting skeletal muscles, is key at this remodelling. METHODS The hypertrophic effect of αCGRP was measured in vitro (cultured cardiac myocytes) and in vivo (magnetic resonance imaging) in mice. Exercise performance was assessed by determination of maximum oxygen consumption and time to exhaustion. Cardiac phenotype was defined by transcriptional analysis, cardiac histology and morphometry. Finally, we measured spontaneous activity, body fat content, blood volume, haemoglobin mass and skeletal muscle capillarization and fibre composition. RESULTS While αCGRP exposure yielded larger cultured cardiac myocytes, exercise-induced heart hypertrophy was completely abrogated by treatment with the peptide antagonist CGRP(8-37). Exercise performance was attenuated in αCGRP(-/-) mice or CGRP(8-37) treated wild-type mice but improved in animals with higher density of cardiac CGRP receptors (CLR-tg). Spontaneous activity, body fat content, blood volume, haemoglobin mass, muscle capillarization and fibre composition were unaffected, whereas heart index and ventricular myocyte volume were reduced in αCGRP(-/-) mice and elevated in CLR-tg. Transcriptional changes seen in αCGRP(-/-) (but not CLR-tg) hearts resembled maladaptive cardiac phenotype. CONCLUSIONS Alpha-calcitonin-gene-related peptide released by skeletal muscles during exercise is a hitherto unrecognized effector directing the strained heart into physiological instead of pathological adaptation. Thus, αCGRP agonists might be beneficial in heart failure patients.

The aim of this study was to evaluate the reproducibility of anatomical landmarks and the accuracy of different cone-beam CTs (CBCTs/DVTs) and a multislice spiral CT (MSCT) scanner.A human, fresh-frozen cadaver head was scanned with four CBCTs (Accuitomo 3D, 3D eXam, Pax Reve 3D, Pax Zenith 3D) and one MSCT (SOMATOM Sensation 64) scanner. The three-dimensional (3D) reconstruction of the volume data sets and location of the anthropometric landmarks (n=11), together with linear (n=5) and angular (n=1) measurements were carried out by three examiners using the program VoXim® 6.1. The measurements were taken twice at a 14-day interval. Descriptive analyses were made and the standard deviations were used to compare differences in the accuracy of landmark identification.The descriptive statistics showed distinct differences in the reference points in the three axes of the coordinate system. Because of anatomical and morphological factors, the pogonion and gnathion reference points displayed higher standard deviations when set on the transverse plane (SD(CBCT) Pog: 0.66-1.57 mm; SD(MSCT) Pog: 0.14-1.09 mm; SD(CBCT) Gn: 1.05-1.77 mm; SD(MSCT) Gn: 0.20-0.85 mm), thus showing less accuracy. However, standard deviations on the sagittal and vertical planes were smaller. Genion, anterior nasal spine and infradentale had very low standard deviations on all three planes. The distance (Mfl-Mfr) and angle (Krl-Krr-Ge) revealed significantly smaller standard deviations in the MSCT (SD(CBCT) Krl-Krr-Ge: 0.51-0.75 mm; SD(MSCT) Krl-Krr-Ge: 0.22 mm).The CBCT devices evaluated in this study are suitable for taking exact 3D measurements of anatomical structures and meet all requirements for 3D cephalometric analysis.

There are various studies in the literature on bonding brackets to bleached teeth and on the effect of bleaching material on the color of compomers. The purpose of this study was to investigate changes in tooth color depending on the process of bonding - debonding and/or bleaching.Ninety crowns of lower bovine permanent incisors were divided into nine subgroups. Three bonding materials (chemical, light- and pressure-cured) and three bleaching materials (15% CP, 35% CP, or 38% HP) were applied to the teeth, whereby each tooth was divided into quarters: untreated, bleached only, bonded-debonded only, and bleached after a bonding-debonding procedure. The Easyshade spectrophotometer was used to determine CIELCh coordinates (lightness, color, and hue) three times for each area. The areas' differences in color were expressed as the Euclidian distance DeltaE. Four examiners (two orthodontists and two dentists) rated each tooth concerning color differences in the four areas. The data collected was subjected to the sign and Wilcoxon or the Kruskal-Wallis and Mann-Whitney U tests using the SPSS 12.0 program.Examiners found significant differences between those areas with and those without bleaching within each group of specimens (p0.05), but there were no differences concerning the bonding and debonding procedures (p0.05). Furthermore, digital tooth-shade measurements revealed no statistically-significant group-associated differences between those areas treated with bonding material and those not so treated, nor between bonded and debonded areas (p0.05). Nor did we observe any statistically-significant differences between bleached areas and those areas bleached after bonding and debonding procedures (p0.05).The processes of bonding and debonding alone do not seem to have any statistically-significant influence on the tooth color of bovine enamel using these testing materials, nor does the subsequent bleaching procedure.

During orthodontic treatment with a multiband appliance, enamel decalcifications and periodontal irritation may occur due to inevitable plaque retention. Besides the band itself, non-cemented gaps between tooth and band constitute a problem that has not yet been investigated from quantitative aspects.In this in vitro study, the cement distribution beneath the orthodontic band was investigated on 48 identical transparent resin replicas of upper molars and lower molars, respectively. The replicas with the cemented orthodontic bands were divided into buccal, distal, oral, and mesial segments so that the inner surfaces of the bands could undergo morphometric analysis for areas not covered with cement. Two different molar bands (Dentaform Snap by Dentaurum, Ispringen, Germany, and "Washbon" by Ormco, Orange, CA, USA), and two glass-ionomer cements (OptiBand by Ormco and Ultra Band-Lok Blue by GAC, Gräfelfing, Germany) were used. In this way, 8 test series with twelve specimens each were performed.Not one cement-band combination was without defects in the cement film, with poorer cement flow properties being observed at the upper than at the lower molars. In general, fewer defects were recorded in the occlusal than in the cervical areas. Overall, the buccal surfaces yielded the best results, and the mesial surfaces the poorest.Since defects in the cement film have so far been unavoidable, the indication for orthodontic treatment with a multiband appliance must continue to be strict. Unless accompanying professional prophylactic care coupled with optimal oral hygiene is ensured, multiband appliances should be used with great caution.

The growth of Agrobacterium tumefaciens in nutrient solution can be inhibited by all ᴅ-amino acids used in these experiments. The degree of inhibition is of different in magnitude; in some cases the inhibition is complete. The inhibition is dependent on the concentration of ᴅ-amino acid and can not be counteracted by addition of L-amino acid or glycine; it is increased by K2CO3. After 28 transfers, all ᴅ-amino acid used in these experiments lead to reduction or complete loss of virulence. It can be assumed that ᴅ-amino acids induce independently loss of virulence and inhibition of growth.