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Biomaterials of natural origin have recently gained increasing attention in the field of dental implantology. The requirements for such materials, however, are very high. In addition to high clinical efficiency in tissue regeneration, wound healing should be demonstrably positively influenced. The translational division for regenerative orofacial medicine of the Clinic and Polyclinic for Oral and Maxillofacial Surgery of the University Medical Center Hamburg-Eppendorf (UKE) is examining this research topic by investigating which innovative treatment methods for the reconstruction of bone defects or for augmentative procedures can be applied in the future or are already being applied in the field of oral and maxillofacial surgery.Biomaterialien natürlichen Ursprungs im Bereich der dentalen Implantologie erhalten in den letzten Jahren vermehrt Aufmerksamkeit, jedoch sind die Anforderungen hoch. Neben einer hohen klinischen Effizienz bei der Geweberegeneration sollte die Wundheilung nachweislich positiv beeinflusst werden. Die translationale Sektion „Regenerative Orofaziale Medizin“ der Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie der Uniklinik Hamburg-Eppendorf (UKE) beschäftigt sich mit diesem Thema und untersucht, welche innovativen Behandlungsmethoden zur Rekonstruktion von Knochendefekten oder bei augmentativen Verfahren im Bereich der Mund-, Kiefer- und Gesichtschirurgie zukünftig Anwendung finden oder bereits angewendet werden.

Titanium dioxide (TiOThe investigators implemented a retrospective cross-sectional study and enrolled a sample of 60 subjects from a dental practice. Subjects were excluded if the plaque index was grade 3 (Silness and Löe). The predictor variable was a positive or negative TiOThe sample was composed of 35 female and 25 male patients with a mean age of 54.2 years (standard deviation = 14.76). The overall TiOThe data in this study showed a statistically significant relationship between a positive TiO

Silk fibroin is a biomaterial with multiple beneficial properties for use in regenerative medicine and tissue engineering. When dissolving and processing the reconstituted silk fibroin solution by electrospinning, the arrangement and size of fibers can be manifold varied and according fiber diameters reduced to the nanometer range. Such nonwovens show high porosity as well as potential biocompatibility. Usually, electrospinning of most biomaterials demands for the application of additives, which enable stable electrospinning by adjusting viscosity, and are intended to evaporate during processing or to be washed out afterwards. However, the use of such additives increases costs and has to be taken into account in terms of biological risks when used for biomedical applications. In this study, we explored the possibilities of additive-free electrospinning of pure fibroin nonwovens and tried to optimize process parameters to enable stable processing. We used natural silk derived from the mulberry silkworm Bombyx mori. After degumming, the silk fibroin was dissolved and the viscosity of the spinning solution was controlled by partial evaporation of the initial solving agent. This way, we were able to completely avoid the use of additives and manufacture nonwovens, which potentially offer higher biocompatibility and reduced immunogenicity. Temperature and relative humidity during electrospinning were systematically varied (25–35 °C, 25–30% RH). In a second step, the nonwovens optionally underwent methanol treatment to initiate beta-sheet formation in order to increase structural integrity and strength. Comprehensive surface analysis on the different nonwovens was performed using scanning electron microscopy and supplemented by additional mechanical testing. Cytotoxicity was evaluated using BrdU-assay, XTT-assay, LDH-assay and live-dead staining. Our findings were, that an increase of temperature and relative humidity led to unequal fiber diameters and defective nonwovens. Resistance to penetration decreased accordingly. The most uniform fiber diameters of 998 ± 63 nm were obtained at 30 °C and 25% relative humidity, also showing the highest value for resistance to penetration (0.20 N). The according pure fibroin nonwoven also showed no signs of cytotoxicity. However, while the biological response showed statistical evidence, the material characteristics showed no statistically significant correlation to changes of the ambient conditions within the investigated ranges. We suggest that further experiments should explore additional ranges for temperature and humidity and further focus on the repeatability of material properties in dependency of suitable process windows., Graphical abstract Image 1, Highlights • Usually, electrospinning of most biomaterials demands for the application of additives. However, the use of such additives increases costs and has to be taken into account in terms of biological risks. • After degumming, fibroin was dissolved and the viscosity of the spinning solution was controlled by partial evaporation of the initial solving agent. In this way, we were able to completely avoid the use of additives. • Using a pure fibroin solution contributes to higher biocompatibility and reduces immunogenicity of the products. • Increase of temperature and humidity led to unequal fiber diameters and defective nonwovens. The most uniform fiber diameters of 998 ± 63 nm were obtained at 30 °C and 25% RH.

Objectives: Zirconia (Y-TZP) ceramics are considered as posterior fixed partial denture (FPD) materials; however, their applications are limited due to chipping. The use of monolithic lithium disilicate (LiDi) glass ceramics in posterior FPDs can be advantageous. This in vitro study aims to compare the loads until failure of posterior Y-TZP-FPDs and LiDi-FPDs before and after aging.

The influence of UV light and non-thermal plasma on the osseointegration of yttria-stabilized zirconia implants (Y-TZP) comparing the two methods is unclear. The aim of this study was to show the influence of these methods on the osseointegration of dental zirconia implants in an animal model. A total of 54 implants were either untreated, treated with UV light (UV), or non-thermal oxygen plasma for 12 min and inserted into the parietal bones of six domestic pigs. The animals were sacrificed after a healing interval of two, four, and nine weeks. The degree of osseointegration was determined using histomorphometric determination of bone-to-implant contact values (BIC) and the bone-to-implant contact values within the retentive parts of the implants (BAFO). BIC values decreased in all groups after four weeks of healing and re-increased after nine weeks in all groups. BAFO increased significantly over time in all groups. However, there were no statistically significant differences in BIC and BAFO values between the control group and the test groups and over time. Clinical studies may follow to confirm the influence of cold plasma and UV light on the healing and survival of zirconia implants.

Studies evaluating plate-related complications in patient-specific versus conventional fixation systems in free flap surgery are lacking. This was a retrospective study of 128 osseous free flaps with a minimum follow-up of 12 months. Wound healing disorders, plate exposure, fixation failure, and subtotal osseous union were recorded and evaluated statistically by univariate and regression analysis. Complication rates were as follows: wound healing disorders 33.6% (computer-aided design and computer-aided manufacturing (CAD/CAM) vs. conventional: 35.1% vs. 33.0%); plate exposure 21.9% (29.7% vs. 18.7%); fixation failure 7.0% (8.1% vs. 6.6%); subtotal osseous union 36.7% (45.9% vs. 33.0%). Radiotherapy (P

Background/Aim: High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo. Materials and Methods: Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines. Results: Cells showed a significantly decreased proliferation (p

Tissue adhesives have been successfully used in various kind of surgeries such as oral and maxillofacial surgery for some time. They serve as a substitute for suturing of tissues and shorten treatment time. Besides synthetic-based adhesives, a number of biological-based formulations are finding their way into research and clinical application. In natural adhesives, proteins play a crucial role, mediating adhesion and cohesion at the same time. Silk fibroin, as a natural biomaterial, represents an interesting alternative to conventional medical adhesives. Here, the most commonly used bioadhesives as well as the potential of silk fibroin as natural adhesives will be discussed.

Ultraviolet (UV) light and non-thermal plasma (NTP) are promising chair-side surface treatment methods to overcome the time-dependent aging of dental implant surfaces. After showing the efficiency of UV light and NTP treatment in restoring the biological activity of titanium and zirconia surfaces in vitro, the objective of this study was to define appropriate processing times for clinical use. Titanium and zirconia disks were treated by UV light and non-thermal oxygen plasma with increasing duration. Non-treated disks were set as controls. Murine osteoblast-like cells (MC3T3-E1) were seeded onto the treated or non-treated disks. After 2 and 24 h of incubation, the viability of cells on surfaces was assessed using an MTS assay. mRNA expression of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were assessed using real-time reverse transcription polymerase chain reaction analysis. Cellular morphology and attachment were observed using confocal microscopy. The viability of MC3T3-E1 was significantly increased in 12 min UV-light treated and 1 min oxygen NTP treated groups. VEGF relative expression reached the highest levels on 12 min UV-light and 1 min NTP treated surfaces of both disks. The highest levels of HGF relative expression were reached on 12 min UV light treated zirconia surfaces. However, cells on 12 and 16 min UV-light and NTP treated surfaces of both materials had a more widely spread cytoskeleton compared to control groups. Twelve min UV-light and one min non-thermal oxygen plasma treatment on titanium and zirconia may be the favored times in terms of increasing the viability, mRNA expression of growth factors and cellular attachment in MC3T3-E1 cells.

Ultraviolet (UV) light and non-thermal plasma (NTP) treatment are chairside methods that can efficiently improve the biological aging of implant material surfaces caused by customary storage. However, the behaviors of stem cells on these treated surfaces of the implant are still unclear. This study aimed to investigate the effects of UV light and NTP treated surfaces of titanium, zirconia and modified polyetheretherketone (PEEK, BioHPP) on the attachment and osteogenic potential of human dental pulp stem cells (DPSCs) in vitro. Machined disks were treated using UV light and argon or oxygen NTP for 12 min each. Untreated disks were set as controls. DPSCs were cultured from the wisdom teeth of adults that gave informed consent. After 24 h of incubation, the attachment and viability of cells on surfaces were assessed. Cells were further osteogenically induced, alkaline phosphatase (ALP) activity was detected via a p-Nitrophenyl phosphate assay (day 14 and 21) and mineralization degree was measured using a Calcium Assay kit (day 21). UV light and NTP treated titanium, zirconia and BioHPP surfaces improved the early attachment and viability of DPSCs. ALP activity and mineralization degree of osteoinductive DPSCs were significantly increased on UV light and NTP treated surfaces of titanium, zirconia and also oxygen plasma treated Bio-HPP (p < 0.05). In conclusion, UV light and NTP treatments may improve the attachment of DPSCs on titanium, zirconia and BioHPP surfaces. Osteogenic differentiation of DPSCs can be enhanced on UV light and NTP treated surfaces of titanium and zirconia, as well as on oxygen plasma treated Bio-HPP.

Background/aim Clonogenicity is a key feature of stem/progenitor cells. The present study aimed to enrich stem/progenitor cells from dental pulp cells by means of culturing the cells at a low clonal density with spatial separation and the evaluate differentiation potential of the surviving cells. Materials and methods Pulp cells derived from wisdom teeth were seeded into wells of a 96-plate at a mean density of 1 cell/well and cultured for 2 weeks. Surviving cells were harvested, pooled together and subjected to differentiation into adipocytes, osteoblasts and neurons using respective inducing conditions for 3 weeks. The former two types of cells were examined by staining with Oil Red O and Alizarin Red, respectively. Neuron-like cells were inspected for their morphology and immunostained for microtubule-associated protein 2 and β-tubulin III. Results Vital cells were obtained in eight wells of a 96-well plate, corresponding to a survival rate of 8%. Since fewer than two wells would be expected to contain more than four cells at seeding, the majority of surviving cells likely grew from 1-3 cells, which is a very low density. These cells differentiated into functional adipocytes and osteoblasts, and morphologically neuron-like cells. Conclusion Low-density seeding with spatial separation enables statistical estimation of cell number in wells and provides an effective strategy for enriching stem/progenitor cells and for isolating clonal dental pulp cells.

Cold plasma treatment increases the hydrophilicity of the surfaces of implants and may enhance their integration with the surrounding tissues. The implaPrep prototype device from Relyon Plasma generates cold atmospheric plasma via dielectric barrier discharge (DBD). In this study, titanium surfaces were treated with the implaPrep device for 20 s and assessed as a cell culture surface for fibroblasts. One day after seeding, significantly more cells were counted on the surfaces treated with cold plasma than on the untreated control titanium surface. Additionally, the viability assay revealed significantly higher viability on the treated surfaces. Morphological observation of the cells showed certain differences between the treated and untreated titanium surfaces. While conventional plasma devices require compressed gas, such as oxygen or argon, the implaPrep device uses atmospheric air as the gas source. It is, therefore, compact in size and simple to handle, and may provide a safe and convenient tool for treating the surfaces of dental implants, which may further improve the implantation outcome.

The aim of this study was to compare UV light and non-thermal plasma (NTP) treatment regarding the improvement of physical material characteristics and cell reaction on titanium surfaces in vitro after short-term functionalization. Moderately rough (Ra 1.8–2.0 μm) sandblasted and acid-etched titanium disks were treated by UV light (0.05 mW/cm2 at λ = 360 nm and 2 mW/cm2 at λ = 250 nm) or by NTP (24 W, -0.5 mbar) of argon or oxygen for 12 min each. Surface structure was investigated by scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy (XPS). Hydrophilicity was assessed by dynamic contact angle measurement. Cell attachment, viability, cell proliferation and cytotoxicity were assessed in vitro using murine osteoblast-like cells. UV irradiation or NTP treatment of titanium surfaces did not alter the surface structure. XPS analysis revealed a significantly increased oxidation of the surface and a decrease of carbon after the use of either method. NTP and UV light led to a significant better cell attachment of murine osteoblasts; significantly more osteoblasts grew on the treated surfaces at each time point (p

A number of modifications have been developed in order to enhance surface cytocompatibility for prosthetic support of dental implants. Among them, ultraviolet (UV) light and non-thermal plasma (NTP) treatment are promising methods. The objective of this study was to compare the effects of UV light and NTP on machined titanium, zirconia and modified polyetheretherketone (PEEK, BioHPP) surfaces in vitro. Machined samples of titanium, zirconia and BioHPP were treated by UV light and NTP of argon or oxygen for 12 min each. Non-treated disks were set as controls. A mouse fibroblast and a human gingival fibroblast cell line were used for in vitro experiments. After 2, 24 and 48 h of incubation, the attachment, viability and cytotoxicity of cells on surfaces were assessed. Results: Titanium, zirconia and BioHPP surfaces treated by UV light and oxygen plasma were more favorable to the early attachment of soft-tissue cells than non-treated surfaces, and the number of cells on those treated surfaces was significantly increased after 2, 24 and 48 h of incubation (p &lt, 0.05). However, the effects of argon plasma treatment on the cytocompatibility of soft tissue cells varied with the type of cells and the treated material. UV light and oxygen plasma treatments may improve the attachment of fibroblast cells on machined titanium, zirconia and PEEK surfaces, that are materials for prosthetic support of dental implants.

Background/aim Silk is a natural biomaterial with several superior features for applications in regenerative medicine. In the present study an optimized process for manufacturing porous scaffolds out of the silk protein fibroin was developed. Materials and methods The silk protein fibroin was dissolved in Ajisawa's reagent and the resulting fibroin solution was used to produce scaffolds by means of freeze-thawing cycling. Porosity, pressure and stab resistance as well as degradation behavior were assessed in order to characterize the physical properties of the resulting scaffolds. Results The resulting sponge-like fibroin scaffolds were highly porous while the porosity correlated inversely with the concentration of the starting fibroin solution. Increased initial fibroin concentrations of the scaffolds resulted in increased compressive and cannulation resistance. The majority of the fibroin scaffolds were digested by 1 mg/ml protease XIV in 3 weeks, indicating their biodegradability. Conclusion The production of scaffolds made of varying fibroin concentrations by means of freeze-thawing, following dissolution using Ajisawa's reagent, provides a simple and straightforward strategy for adjusting the physical and chemical properties of fibroin scaffolds for various medical applications.

ZusammenfassungBenigne Weichteiltumoren treten mit einer Inzidenz von 300/100 000 auf. Sie sind häufig im Kopf-Hals-Bereich lokalisiert. Das klinische Erscheinungsbild ist aufgrund der vielen verschiedenen Entitäten variabel und beinhaltet durch die hier engen Lagebeziehungen oft neben einer Schwellung auch funktionelle Einschränkungen des Kau-, Schluck-, Sprech-, Hör- und Sehapparats. Neben Anamnese und körperlicher Untersuchung sind vor allem die Sonografie und Magnetresonanztomografie diagnostische Mittel. Die Therapie besteht zumeist in einer kompletten Resektion.

Purpose Immediate loading of dental implants has been proved to be feasible in partially edentulous jaws. The purpose of this retrospective investigation was to assess the feasibility of immediately loading dental implants in fully edentulous jaws. Methods A total of 24 patients aged between 53 and 89 years received a total of 154 implants in their edentulous maxillae or mandibles. Among the implants, 45 were set in fresh extracted sockets and 109 in consolidated alveolar bones. The implants were provisionally managed with chair-side made provisional resin bridges and exposed to immediate loading. Implants were followed up for 1–8 years, including radiographic imaging. Marginal bone levels were evaluated based on radiographic imaging. Results A total of 148 out of the 154 implants survived over the follow-up period of 1 to 8 years, giving a survival rate of 96%. The time or region of the implantation, the pre-implant augmentation, and the length and diameter of the implants had no statistically significant influence on the survival or the success rate. The marginal bone level remained stable with only minimal loss of 0.3 mm after 60 months of loading. Conclusions Within the limitations of this study, immediate loading is feasible for dental implants in edentulous jaws., Graphical Abstract

Magnesium (Mg)-based biomaterials are promising candidates for bone and tissue regeneration. Alloying and surface modifications provide effective strategies for optimizing and tailoring their degradation kinetics. Nethertheless, biocompatibility analyses of Mg-based materials are challenging due to its special degradation mechanism with continous hydrogen release. In this context, the hydrogen release and the related (micro-) milieu conditions pretend to strictly follow in vitro standards based on ISO 10993-5/-12. Thus, special adaptions for the testing of Mg materials are necessary, which have been described in a previous study from our group. Based on these adaptions, further developments of a test procedure allowing rapid and effective in vitro cytocompatibility analyses of Mg-based materials based on ISO 10993-5/-12 are necessary. The following study introduces a new two-step test scheme for rapid and effective testing of Mg. Specimens with different surface characteristcis were produced by means of plasma electrolytic oxidation (PEO) using silicate-based and phosphate-based electrolytes. The test samples were evaluated for corrosion behavior, cytocompatibility and their mechanical and ostogenic properties. Thereby, two PEO ceramics could be identified for further in vivo evaluations.

PURPOSE To compare the influence of ultraviolet (UV) irradiation and cold atmospheric pressure plasma (CAP) treatment on surface structure, surface chemistry, cytocompatibility, and cell behavior on zirconia in vitro. MATERIALS AND METHODS Zirconia samples (TZ-3YSBE) were treated by UV irradiation, oxygen plasma, or argon plasma for 12 minutes each and compared with the nontreated samples. Surface analysis was conducted using scanning electron microscopy, roughness analysis, and x-ray photoelectron spectroscopy. Cell proliferation, viability, and cell attachment as well as cytotoxicity were evaluated using MC3T3-E1 murine osteoblasts cultivated directly on the zirconia samples. RESULTS Surface structure and roughness were not affected by the surface treatments. CAP and UV irradiation significantly reduced organic material and increased the surface oxidation on the zirconia samples. Furthermore, CAP and UV treatment significantly decreased the contact angle on the zirconia samples, indicating superhydrophilicity. Cell attachment was significantly increased on oxygen plasma-treated zirconia samples compared with the nontreated samples at all times (P < .001). After 24 and 48 hours, cell proliferation and viability (P < .001) were significantly increased on oxygen plasma-treated samples in comparison with the nontreated, UV-treated, and argon plasma-treated samples. Neither UV nor CAP treatment led to cytotoxicity. CONCLUSION In vitro, surface treatment by UV irradiation or CAP causes a significant reduction of organic material, increases the hydrophilicity of zirconia, and improves the conditions for osteoblasts. Results stipulate that treatment of zirconia surfaces with oxygen plasma may favor cell proliferation.

Background/Aim: High-density porous polyethylene (PP) offers possibilities for reconstruction in craniofacial surgery. The purpose of this study was to evaluate the extent of inflammation and foreign body reactions to PP in vitro and in vivo. Materials and Methods: Cell attachment, proliferation and expression of inflammatory cytokines were assessed using murine macrophages (RAW 264.7) on two different PP materials in vitro. In vivo, Balb/c mice received PP implants at their dorsum. After sacrifice, samples were analyzed histologically and real-time PCR was used to assess expression of inflammatory cytokines. Results: Cells showed a significantly decreased proliferation (p

Magnesium (Mg)-based biomaterials are promising candidates for bone and tissue regeneration. Alloying and surface modifications provide effective strategies for optimizing and tailoring their degradation kinetics. Nevertheless, biocompatibility analyses of Mg-based materials are challenging due to its special degradation mechanism with continuous hydrogen release. In this context, the hydrogen release and the related (micro-) milieu conditions pretend to strictly follow in vitro standards based on ISO 10993-5/-12. Thus, special adaptions for the testing of Mg materials are necessary, which have been described in a previous study from our group. Based on these adaptions, further developments of a test procedure allowing rapid and effective in vitro cytocompatibility analyses of Mg-based materials based on ISO 10993-5/-12 are necessary. The following study introduces a new two-step test scheme for rapid and effective testing of Mg. Specimens with different surface characteristics were produced by means of plasma electrolytic oxidation (PEO) using silicate-based and phosphate-based electrolytes. The test samples were evaluated for corrosion behavior, cytocompatibility and their mechanical and osteogenic properties. Thereby, two PEO ceramics could be identified for further in vivo evaluations., International journal of molecular sciences;Jg. 20, Heft 2. S. 255-1-255-20

In an effort to generate titanium surfaces for implants with improved osseointegration, we used direct laser interference patterning (DLIP) to modify the surface of pure titanium grade 4 of four different structures. We assessed in vitro cytoxicity and cell attachment, as well as the viability and proliferation of cells cultured directly on the surfaces. Attachment of the cells to the modified surfaces was comparably good compared to that of cells on grit-blasted and acid-etched reference titanium surfaces. In concordance with this, viability and proliferation of the cells directly cultured on the specimens were similar on all the titanium surfaces, regardless of the laser modification, indicating good cytocompatibility.

Positive effects of irradiation with ultraviolet (UV) light or treatment with non-thermal plasma on titanium and zirconia surfaces have been described in various studies. The aim of this study was to assess and compare the changes in the physicochemical surface conditions of titanium and zirconia surfaces after a short treatment with UV light or with non-thermal plasmas of argon or oxygen. Titanium and zirconia samples with moderately rough surfaces were treated for 12 min either in a UV-light oven or in a non-thermal plasma reactor that generates non-thermal plasmas of oxygen or argon. Changes in surface conditions were assessed by confocal microscopy, dynamic contact angle measurement, and X-ray photoelectron spectroscopy (XPS). No changes in roughness occurred. Ultraviolet irradiation and non-thermal plasma significantly increased the wettability of the titanium and zirconia surfaces. X-ray photoelectron spectroscopy showed an increase of oxygen and a significant decrease of carbon after treatment with either method. Thus, ultraviolet light and non-thermal plasma were found to be able to improve the chemical surface conditions of titanium and zirconia following a short exposure time. However, further in vitro and in vivo studies are needed to determine the relevance of the results.

Purpose The preservation of peri-implant bone is one requirement for long-term success of dental implants. The purpose of this study was to evaluate the impact of subcrestal placement on the crestal bone level of immediate versus delayed placed implants after loading. Materials and methods In this retrospective study, data of 159 patients who received 330 implants was analyzed. Implants were placed subcrestally, crestally or supracrestally into fresh sockets or healed sites. Vertical bone level height was assessed radiographically and implants were followed up annually. The influence of patient and implant related risk factors for peri-implant bone loss was evaluated using a linear mixed model. Results Depth of implant placement was significantly correlated with peri-implant bone loss (P = 0.001, 95% CI). Least effective loss of crestal bone was determined when implants were placed between 1 mm and 1.99 mm subcrestally. Smoking significantly enhanced the risk of peri-implant bone loss (P = 0.04, 95% CI). Immediate implant placement was not positively correlated with peri-implant bone loss (P = 0.51, 95% CI). Conclusion Within the limits of this study, implant placement 1.08 mm subcrestally may be recommendable in order to avoid supracrestal expositions of platform-switched titanium implants over time.

Background/Aim: Plasma electrolytic oxidation (PEO) is an established electrochemical treatment technique that can be used for surface modifications of metal implants. In this study we to treated titanium implants with PEO, to examine the resulting microstructure and to characterize adhesion and viability of cells on the treated surfaces. Our aim was to identify an optimal surface-modification for titanium implants in order to improve soft-tissue integration. Materials and Methods: Three surface-variants were generated on titanium alloy Ti6Al4V by PEO-treatment. The elemental composition and the microstructures of the surfaces were characterized using energy dispersive X-ray spectroscopy, scanning electron microscopy and profilometry. In vitro cytocompatibility of the surfaces was assessed by seeding L929 fibroblasts onto them and measuring the adhesion, viability and cytotoxicity of cells by means of live/dead staining, XTT assay and LDH assay. Results: Electron microscopy and profilometry revealed that the PEO-surface variants differed largely in microstructure/topography, porosity and roughness from the untreated control material as well as from one another. Roughness was generally increased after PEO-treatment. In vitro, PEO-treatment led to improved cellular adhesion and viability of cells accompanied by decreased cytotoxicity. Conclusion: PEO-treatment provides a promising strategy to improve the integration of titanium implants with surrounding tissues.

Purpose Immediate loading of dental implants has been evolving into an appropriate procedure for the treatment of partially edentulous jaws. The purpose of this study was to evaluate the clinical success and radiological outcome of immediately and delayed loaded dental implants in anterior and premolar sites. Materials and methods In this retrospective study, data of 163 individuals requiring tooth removal with subsequent implant placement in anterior and premolar sites were analyzed. Implants were immediately loaded by provisional acrylic resin bridges or loaded with delay. Implants were followed up annually for up to 9 years including intraoral radiographs. Results A total of 285 implants in 163 patients were placed. 218 implants were immediately loaded and 67 implants with delay. Fifteen implants failed during the follow-up period resulting in survival rates of 94.5% for immediate loading and 95.5% for delayed loading. After an initial decrease of 0.3 mm in the first 12 months the marginal bone level remained stable. No statistically significant differences were found in marginal bone loss between immediately and delayed loaded implants (P = 0.518, 95% CI). Conclusion Within the limits of this study, immediate loading of immediately subcrestally placed dental implants in anterior and premolar sites is a reliable treatment option for dental rehabilitation.

Epidermal growth factor receptor (EGFR) expression is altered in several malignancies, including oral squamous cell carcinoma. A CA-repeat polymorphism in intron-1 (CA-SSR-1) of the EGFR gene is reported to influence EGFR expression and is associated with features of various solid tumors and outcomes of cancer patients. In the present study we evaluated the influence of length and zygosity of CA-SSR-1 on the survival of patients with oral squamous cell carcinoma. The length and zygosity of CA-SSR-1 was obtained through microsatellite analysis in 91 patients with oral cancer, who were treated in the Department of Oral and Maxillofacial Surgery of the University Medical Centre Hamburg Eppendorf, Germany, during the years 1998-2008. Follow up was conducted until 2016. Outcome measures were age, gender, tumor stage, occurrence of metastases, and date of recurrence or death. Statistical analysis was conducted using the chi-square test and the log-rank test. Neither length nor zygosity of the CA-SSR-1 in patients with oral squamous cell carcinoma was significantly correlated with sex, age, tumor size, tumor localization, lymph node involvement, metastasis status, disease-free survival, or overall survival. Length and zygosity of the CA-SSR-1 polymorphism in EGFR is not able to serve as a prognostic biomarker in White European patients with oral squamous cell carcinoma.

Purpose The objective of surgical fracture management is to reduce and fixate fractures accurately and rapidly. Two osteosynthesis plates are usually used in the treatment of mandibular angle fractures to enhance torsional stiffness. We conducted biomechanical tests under static and cyclic loading to assess whether a single locking plate is as efficacious as two conventional plates in the osteosynthesis of mandibular angle fractures. Materials and methods Fracture gaps were created in synthetic mandible replicas. After pretests, the stiffness of a single locking plate and different types of non-locking, two-plate systems was assessed and compared under static and cyclic loading. The plates were subjected to a maximum static load of 750 N and underwent cyclic loading at a constant force of 400 N during a maximum of 500,000 cycles. Results No plastic deformation occurred in the static tests. Both types of osteosynthesis showed high static stability. The locking plate was significantly stiffer than the non-locking plates (p = 0.0079). Cyclic loading tests did not reveal any significant differences. Conclusion Within the limitations of this preliminary study, a single locking miniplate appears to be as efficacious in biomechanical tests as non-locking, two-plate systems for the management of mandibular angle fractures.

To report the outcome of graftless osteotome sinus floor elevation (OSFE) in order to evaluate whether apical bone gain depends on the initial residual bone height and whether the initial residual bone height has an influence on the amount of marginal bone loss. Furthermore the study aimed to assess if perforations of the Schneiderian membrane or residual bone height are potential predictors of implant survival.In this retrospective study all patients were included who were treated between 2001 and 2010 and received dental implants in combination with OSFE in a private practice. Patients having 1 to 11 mm of residual bone height were subjected to crestal sinus lift elevation. One hundred and thirteen patients with 233 implants were included in this study. The follow-up period was 5-years post-loading for all patients. The average initial bone level height was 5.9 ± 1.7 mm. No bone graft or substitute material was used. All implants healed transgingivally and were loaded 3 months after insertion. Outcome measures were prosthetic success, implant success, complications, radiographic crestal bone level changes and apical (sinus floor) bone height.Sixty-three patients dropped out during the 5-year post-loading follow-up. Seven implants in 7 patients failed. Implant survival rate 5 years after loading was 93.8% at patient level. Implants succeeded in 92.7% of all cases. In six patients (5.3%), prostheses failed and had to be remade. Minor complications like small ceramic fractures and loosening of prosthetics were observed in seven patients (6.2%). Average marginal bone loss at 5 years of follow-up was 0.5 ± 0.8 mm per patient. No correlation was found between marginal bone loss and initial residual bone height. Average gained bone height was 4.5 ± 1.4 mm after 5 years of loading. We found a significantly negative linear correlation for apical bone gain depending on the baseline bone level (P 0.001). The apical bone gain was higher in cases with less residual bone.Implants after graftless osteotome sinus floor elevation showed excellent survival and success rates after 5 years of loading. Apical gain of newly formed bone was positively correlated with the initial bone height showing a statistical significance. However, initial residual bone height is also a predictor for implant survival, i.e. survival increases by 1.6 times with every additional millimetre of initial residual bone height. Conflict-of-interest statement: All authors declare that they have neither financial nor non-financial competing interests.

Peripheral nerve injury is a common clinical entity, which may arise due to traumatic, tumorous, or even iatrogenic injury in craniomaxillofacial surgery. Despite advances in biomaterials and techniques over the past several decades, reconstruction of nerve gaps remains a challenge. Autografts are the gold standard for nerve reconstruction. Using autografts, there is donor site morbidity, subsequent sensory deficit, and potential for neuroma development and infection. Moreover, the need for a second surgical site and limited availability of donor nerves remain a challenge. Thus, increasing efforts have been directed to develop artificial nerve guidance conduits (ANCs) as new methods to replace autografts in the future. Various synthetic conduit materials have been testedin vitroandin vivo,and several first- and second-generation conduits are FDA approved and available for purchase, while third-generation conduits still remain in experimental stages. This paper reviews the current treatment options, summarizes the published literature, and assesses future prospects for the repair of peripheral nerve injury in craniomaxillofacial surgery with a particular focus on facial nerve regeneration.

OBJECTIVE: To determine the lingual surface morphology of central and lateral upper incisors evaluating constant morphological regions for better adhesion of industrial prefabricated lingual brackets. MATERIAL AND METHODS: A total of 102 randomly selected patients at the end of the first phase of second dentition with intact central and lateral upper incisors participated in this study. After impression taking and cast model preparation, 3D laser scans of the lingual surface of the upper central and lateral incisors were taken (Laserscan 3D®, Willytec, Munich, Germany), digitalised, and transferred into CAD software to analyse the surface morphology by superimposition. For better comparison of morphological variations and determination of the most constant lingual regions, the surface was divided into five parts: incisal edge, mesial ridge, lateral ridge, cingulum, and medial sector. Statistical analysis was performed by the paired t-test. RESULTS: Statistically significant differences were found in all surfaces, with cingulum as the most inconstant region. The most constant region was the medial sector and the mesial ridge. CONCLUSION: As expected, the lingual surface underlies a high intra-individual variation complicating industrial prefabricated lingual brackets adhesion. However, the mesial ridge and the medial sector seem to be the most constant regions within intra-individual morphological variations.

The aim of the present study was the assessment of metatarsal head loading in combat boots of the German armed forces. With respect to the prevention of metatarsal stress fractures, we evaluated how cushioning insoles (made of EVA foam or neoprene) achieved a load reduction in comparison with conventional insoles.Local pressure, force and impulse values were determined with the pedar-m expert in-shoe pressure measurement system applied in 26 volunteers during walking with four different insoles made of synthetic mesh, EVA foam and neoprene. Data analysis was performed with SAS and tested for statistical differences with non-parametric tests (with p0.05 as a significance level).For the peak pressures under the metatarsal heads (MT) the following order was found: MT-IIMT-IIIMT-IMT-IVMT-V. A comparison of the insoles indicated that the neoprene insole resulted in the lowest peak pressures with significant load reductions under MT-III to MT-V (p0.00001). Furthermore, the impulse values under MT-II to MT-V were significantly lower with neoprene insoles (p0.0002). However, the subjects rated the conventional insoles as more comfortable and better fitting than the newly developed insoles.The cushioning insoles were superior to the conventional insoles with respect to the plantar pressure distribution. With respect to the load reduction we can conclude that the modified insoles might be able to reduce the incidence of march fractures. The biomechanical advantage does not appear to be related to personal preferences.

Head & face medicine 10, 34 (2014). doi:10.1186/1746-160X-10-34, Published by BioMed Central, London