Microbial colonization on 3D-printed zirconia restorations may aggravate plaque accumulation and periodontal inflammation. While additive manufacturing (AM) parameters significantly influence surface roughness and morphology, evidence regarding their impact on bacterial adhesion remains unclear. This study investigated the effects of AM technologies and build angles on the surface characteristics and initial microbial adhesion of 3D-printed zirconia. Zirconia discs were fabricated using material jetting (MJ, 10 μm layer thickness) and digital light processing (DLP, 30 μm layer thickness) technologies with three build angles (0°, 45°, and 90°), respectively (n = 25 per group). The surface topographic features and roughness were analyzed using scanning electron microscopy and laser scanning microscopy, respectively. The surface wettability was evaluated via water contact angle measurements. Streptococcus gordonii (S. gordonii) was used to assess bacterial adhesion, which was evaluated via colony-forming unit counts and visualized through SEM imaging. Statistical analysis involved two-way ANOVA and post hoc Tukey tests, with significance threshold set at p < 0.05. AM technologies and build angle significantly affected surface characteristics, with significant interactions observed for roughness (p < 0.05). DLP-45° showed the roughest surface, while DLP-0° was the smoothest. Water contact angle varied significantly with both factors (p < 0.05), with MJ-45° showing the highest wettability. For S. gordonii adhesion, a significant interaction between AM methods and build angle was found (p < 0.05), and AM methods showed a main effect (p = 0.0104), while build angle alone was not significant (p = 0.0642). The least adhesion occurred in MJ-45° and DLP-0°, with no consistent correlation between roughness and bacterial adhesion. AM technologies and build angle affected S. gordonii adhesion to zirconia surfaces. DLP printing at 0° and MJ printing at 45° were associated with significantly reduced bacterial counts, presenting a clinically approach to minimize initial plaque formation and support the long-term periodontal success of 3D-printed zirconia restorations.

OBJECTIVES:The present study investigated how printing angle and layer thickness influence the surface characteristics and initial microbial adhesion to zirconia fabricated via digital light processing (DLP). METHODS:A total of 156 zirconia specimens were fabricated and divided into six groups based on two layer thicknesses of 30 and 50 μm and three build angles of 0°, 45°, and 90°. The surface topography and roughness were analyzed using scanning electron microscopy and laser scanning microscopy, respectively. The surface wettability was evaluated via water contact angle measurements. The initial adhesion of Streptococcus gordonii (S. gordonii) was assessed by colony-forming unit counts (n = 6). Two specimens per group were fixed, dehydrated, and examined for biofilm observation by scanning electron microscopy. Two-way ANOVA and Tukey multiple comparison tests were conducted. Statistical significance was set at p < 0.05. RESULTS:The layer thickness and build angle significantly affected surface roughness (arithmetic mean height, Sa) and water contact angle (degree) values (p < 0.05). SEM analyses revealed that microbial colonies predominantly accumulated in grooves at a 45° build angle. Quantitative assessments demonstrated that printing angle (F(2, 102)=31.68, p < 0.0001) and layer thickness (F(1, 102)=15.74, p = 0.0001) significantly affected S. gordonii adhesion. CONCLUSIONS:Printing layer thickness and build angle significantly influenced DLP-printed zirconia's surface roughness and water contact angle. Furthermore, they significantly impacted the adhesion of S. gordonii to zirconia surfaces. CLINICAL SIGNIFICANCE:Proper build angle and layer thickness are crucial for optimizing the surface morphology and roughness of 3D-printed zirconia since they affect microbial adhesion. Optimal zirconia applications, especially for transgingival surfaces, are achieved using a 0° printing angle and minimizing layer thickness, improving the clinical outcomes.

Research has highlighted the release of monomers and leachables from additively manufactured (AM) oral devices, raising concerns about their potential biological impact. The oral cavity's dynamic epithelial system necessitates exposure models that accurately reflect real-world conditions. Traditional static models often overestimate or underestimate patient exposure, failing to predict in vivo risks effectively. To address this gap, we developed an advanced dynamic oral tissue exposure model that simulates the release kinetics of leachables, saliva flow, and gingival tissue perfusion. This dynamic approach, integrated with an in vitro human gingival keratinocyte (HGK) model, was applied for the first time in this study. We quantified urethane dimethacrylate (UDMA) release from AM biomaterials through extraction experiments, generating data for computational modeling. The model revealed that dynamic in vivo monomer exposure peaks at specific time points before declining, a pattern not captured by static calculations. In vitro analysis showed that UDMA exposure inhibited metabolic activity and reduced Ki-67 expression in HGK cultures at micromolar concentrations. While inhibitory in vitro concentrations exceeded predicted in vivo estimates, low-dose effects on Ki-67 expression were still observed. These findings suggest that although calculated UDMA exposure remains sub-cytotoxic, it may still induce sensitizing effects. Overall, the dynamic exposure model introduced in this study represents a significant advancement in risk assessment, offering more accurate predictions of the biological effects of leachables and contributing to the safety evaluation of AM biomaterials. STATEMENT OF SIGNIFICANCE: Additively manufactured (AM) oral devices are a significant source of monomer release into the oral cavity, raising concerns about tissue exposure. Traditional static models provide limited or inaccurate risk estimates due to the cavity's dynamic nature. In this study, we developed a dynamic oral tissue exposure model that estimates in vivo-relevant monomer and leachable concentrations in saliva and oral mucosa while integrating an in vitro gingival keratinocyte model to assess biological effects. The model provides key insights into predicted in vivo exposure to monomers and leachables, improving in vitro evaluations of biological effects. Overall, it serves as a valuable risk assessment tool for the research community by enhancing predictions of patient exposure to potential monomers and leachables, thereby supporting AM biomaterial safety.

OBJECTIVES:Inconsistent characterization of oral implant microtopography makes it difficult to compare and evaluate available data on microtopography and the biological response to topographical characteristics. The aim of this investigation was therefore to identify a surface texture parameter panel that enables a discriminative characterization of differently processed oral implant surfaces. MATERIALS AND METHODS:Surface micromorphologies of titanium- and ceramic-based biomaterials processed by machining or by machining and subsequent post-processing, including blasting, etching, anodization or porous sintering, were analyzed by scanning electron microscopy and white light interferometry. It was then analyzed which of the parameters Sa, Sq, Sz, Ssk, Sku, Str, Sal, Spd, Spc, Sdq and Sdr best characterized morphological surface features and hence should be reported as minimum parameter panel for implant surface characterization. RESULTS:SEM demonstrated that each surface processing resulted in a specific and biomaterial-dependent micromorphology. The data revealed that the micromorphology of machined surfaces was best characterized by Sa, Sdr, Str and Ssk, and that for post-processed surfaces Spd and Spc were additionally required. Based on these data, Sa, Sdr, Str, Ssk, Spd and Spc were identified as minimum parameter panel for discriminative description of the investigated implant microtopographies. SIGNIFICANCE:The present investigation identified Sa, Sdr, Str, Ssk, Spd and Spc as minimum parameter panel for discriminative oral implant surface characterization. The widespread use of such a panel combined with biological data will help to identify cell-relevant implant surface structures, thus enabling the design of oral implants with predefined biological response.

To date, it is unknown whether 3D printed fixed oral implant-supported prostheses can achieve comparable soft tissue integration (STI) to clinically established subtractively manufactured counterparts. STI is mediated among others by gingival fibroblasts (GFs) and is modulated by biomaterial surface characteristics. Therefore, the aim of the present work was to investigate the GF response of a 3D printed methacrylate photopolymer and a hybrid ceramic-filled methacrylate photopolymer for fixed implant-supported prostheses in the sense of supporting an STI. Subtractively manufactured samples made from methacrylate polymer and hybrid ceramic were evaluated for comparison and samples from yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP), comprising well documented biocompatibility, served as control. Surface topography was analyzed by scanning electron microscopy and interferometry, elemental composition by energy-dispersive x-ray spectroscopy, and wettability by contact angle measurement. The response of GFs obtained from five donors was examined in terms of membrane integrity, adhesion, morphogenesis, metabolic activity, and proliferation behavior by a lactate-dehydrogenase assay, fluorescent staining, a resazurin-based assay, and DNA quantification. The results revealed all surfaces were smooth and hydrophilic. GF adhesion, metabolic activity and proliferation were impaired by 3D printed biomaterials compared to subtractively manufactured comparison surfaces and the 3Y-TZP control, whereas membrane integrity was comparable. Within the limits of the present investigation, it was concluded that subtractively manufactured surfaces are superior compared to 3D printed surfaces to support STI. For the development of biologically optimized 3D printable biomaterials, consecutive studies will focus on the improvement of cytocompatibility and the synthesis of STI-relevant extracellular matrix constituents.

ObjectivesSurface characteristics of implant reconstructions determine the gingival fibroblast (GF) response and thus soft tissue integration (STI). However, for monolithic implant reconstructions it is unknown whether the (hybrid) ceramic biomaterial type and its surface treatment affect GF response. Therefore, this investigation examined the influence of the implant reconstruction biomaterials hybrid ceramic (HC), lithium disilicate ceramic (LS), 4 and 5 mol% yttria partially stabilized zirconiumdioxide ceramics (4/5Y-PSZ) and their surface treatment - machining, polishing or glazing - on surface characteristics and GF response.MethodsAfter characterization of surface topography and wettability by scanning electron microscopy, interferometry and contact angle measurement, the adhesion, morphology, metabolic activity and proliferation of GFs from six donors was investigated by fluorescent staining and a resazurin-based assay at days 1, 3 and 7. Titanium (Ti) served as control.ResultsBiomaterial type and surface treatment affected the GF response in a topography-dependent manner. Smooth polished and glazed surfaces demonstrated enhanced GF adhesion and earlier proliferation onset compared to rough machined surfaces. Due to minor differences in surface topography of polished and glazed surfaces, however, the GF response was similar for polished and glazed HC, LS, 4- and 5Y-PSZ as well as Ti.SignificanceWithin the limits of the present investigation, polishing and glazing of machined HC, LS and 4/5Y-PSZ can be recommended to support STI-relevant cell functions in GF. Since the GF response on polished and glazed HC, LS, 4- and 5Y-PSZ surfaces and the Ti control was comparable, this investigation proofed equal cytocompatibility of these surfaces in vitro.

The aim of this in vitro study was to investigate the effect of hydrogen peroxide (H2O2) on the surface properties of various zirconia-based dental implant materials and the response of human alveolar bone osteoblasts. For this purpose, discs of two zirconia-based materials with smooth and roughened surfaces were immersed in 20% H2O2 for two hours. Scanning electron and atomic force microscopy showed no topographic changes after H2O2-treatment. Contact angle measurements (1), X-ray photoelectron spectroscopy (2) and X-ray diffraction (3) indicated that H2O2-treated surfaces (1) increased in hydrophilicity (p < 0.05) and (2) on three surfaces the carbon content decreased (33–60%), while (3) the monoclinic phase increased on all surfaces. Immunofluorescence analysis of the cell area and DNA-quantification and alkaline phosphatase activity revealed no effect of H2O2-treatment on cell behavior. Proliferation activity was significantly higher on three of the four untreated surfaces, especially on the smooth surfaces (p < 0.05). Within the limitations of this study, it can be concluded that exposure of zirconia surfaces to 20% H2O2 for 2 h increases the wettability of the surfaces, but also seems to increase the monoclinic phase, especially on roughened surfaces, which can be considered detrimental to material stability. Moreover, the H2O2-treatment has no influence on osteoblast behavior.

In oral and maxillofacial bone reconstruction, autografts from the iliac crest represent the gold standard due to their superior clinical performance, compared to autografts derived from other extraoral regions. Thus, the aim of our study was to identify putative differences between osteoblasts derived from alveolar (hOB-A) and iliac crest (hOB-IC) bone of the same donor (nine donors) by means of their molecular properties in 2D and 3D culture. We thereby focused on the gene expression of biomarkers involved in osteogenic differentiation, matrix formation and osteoclast modulation. Furthermore, we examined the transcriptional response to Vit.D3 in hOB-A and hOB-IC. Our results revealed different modulation modes of the biomarker expression in osteoblasts, namely cell origin/bone entity-dependent, and culture configuration- and/or time-dependent modulations. SEMA3A, SPP1, BGLAP and PHEX demonstrated the strongest dependence on cell origin. With respect to Vit.D3-effects, BGLAP, SPP1 and ALPL displayed the highest Vit.D3-responsiveness. In this context we demonstrated that the transcriptional Vit.D3-response concerning SPP1 and ALPL in human osteoblasts depended on the cell origin. The results indicate a higher bone remodeling activity of iliac crest than alveolar osteoblasts and support the growing evidence that a high osteoclast activity at the host-/donor bone interface may support graft integration.

PURPOSE:The study aim is a comparative proteome-based analysis of different autologous bone entities (alveolar bone [AB], iliac cortical [IC] bone, and iliac spongiosa [IS]) used for alveolar onlay grafting.EXPERIMENTAL DESIGN:Site-matched bone samples of AB, IC, and IS were harvested during alveolar onlay grafting. Proteins were extracted using a detergent-based (sodium dodecyl sulfate) strategy and trypsinized. Proteome analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). MaxQuant was used for peptide-to-spectrum matching, peak detection, and quantitation. Linear models for microarray analysis (LIMMA) were used to detect differentially abundant peptides and proteins.RESULTS:A total of 1730 different proteins were identified across the 15 samples at a false discovery rate of 1%. Partial least-squares discriminant analysis approved segregation of AB, IC, and IS protein profiles. LIMMA statistics highlighted 66 proteins that were more abundant in AB then in IC (vs. 92 proteins were enriched in IC over AB). Gene Ontology enrichment analysis revealed a matrisomal versus an immune-related proteome fingerprint in AB versus IC.CONCLUSION AND CLINICAL RELEVANCE:This pilot study demonstrates an ECM protein-related proteome fingerprint in AB and an immune-related proteome fingerprint in IS and IC.

Dental implants need to combine mechanical strength with promoted osseointegration. Currently used subtractive manufacturing techniques require a multi-step process to obtain a rough surface topogra-phy that stimulates osseointegration. Advantageously, additive manufacturing (AM) enables direct im-plant shaping with unique geometries and surface topographies. In this study, zirconia implants with in-tegrated lamellar surface topography were additively manufactured by nano-particle ink-jetting. The ISO -14801 fracture load of as-sintered implants (516 +/- 39 N) resisted fatigue in 5-55 degrees C water thermo-cycling (631 +/- 134 N). Remarkably, simultaneous mechanical fatigue and hydrothermal aging at 90 degrees C significantly increased the implant strength to 909 +/- 280 N due to compressive stress generated at the seamless tran-sition of the 30-40 mu m thick, rough and porous surface layer to the dense implant core. This unique surface structure induced an elongated osteoblast morphology with uniform cell orientation and allowed for osteoblast proliferation, long-term attachment and matrix mineralization. In conclusion, the developed AM zirconia implants not only provided high long-term mechanical resistance thanks to the dense core along with compressive stress induced at the transition zone, but also generated a favorable osteoblast response owing to the integrated directional surface pores.Statement of significanceZirconia ceramics are becoming the material of choice for metal-free dental implants, however significant effort s are required to obtain a rough/porous surface for enhanced osseointegration, along with the risk of surface delamination and/or microstructure variation. In this study, we addressed the challenge by additively manufacturing implants that seamlessly combine dense core with a porous surface layer. For the first time, a unique surface with a directional lamellar pore morphology was additively obtained. This AM implant also provided strength as strong as conventionally manufactured zirconia implants before and after long-term fatigue. Favorable osteoblast response was proved by in-vitro cell investigation. This work demonstrated the opportunity to AM fabricate novel ceramic implants that can simultaneously meet the mechanical and biological functionality requirements.(c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

As the use of zirconia-based nano-ceramics is rising in dentistry, the examination of possible biological effects caused by released nanoparticles on oral target tissues, such as bone, is gaining importance. The aim of this investigation was to identify a possible internalization of differently sized zirconia nanoparticles (ZrNP) into human osteoblasts applying Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and to examine whether ZrNP exposure affected the metabolic activity of the cells. Since ToF-SIMS has a low probing depth (about 5 nm), visualizing the ZrNP required the controlled erosion of the sample by oxygen bombardment. This procedure removed organic matter, uncovering the internalized ZrNP and leaving the hard particles practically unaffected. It was demonstrated that osteoblasts internalized ZrNP within 24 h in a size-dependent manner. Regarding the cellular metabolic activity, metabolization of alamarBlue by osteoblasts revealed a size- and time-dependent unfavorable effect of ZrNP, with the smallest ZrNP exerting the most pronounced effect. These findings point to different uptake efficiencies of the differently sized ZrNP by human osteoblasts. Furthermore, it was proven that ToF-SIMS is a powerful technique for the detection of zirconia-based nano/microparticles that can be applied for the cell-based validation of clinically relevant materials at the nano/micro scale.

Plasma-treatment of oral implant biomaterials prior to clinical insertion is envisaged as a potential surface modification method for enhanced implant healing. To investigate a putative effect of plasma-functionalized implant biomaterials on oral tissue cells, this investigation examined the response of alveolar bone osteoblasts and gingival fibroblasts to clinically established zirconia- and titanium-based implant surfaces for bone and soft tissue integration. The biomaterials were either functionalized with oxygen-plasma in a plasma-cleaner or left untreated as controls, and were characterized in terms of topography and wettability. For the biological evaluation, the cell adhesion, morphogenesis, metabolic activity and proliferation were examined, since these parameters are closely interconnected during cell-biomaterial interaction. The results revealed that plasma-functionalization increased implant surface wettability. The magnitude of this effect thereby depended on surface topography parameters and initial wettability of the biomaterials. Concerning the cell response, plasma-functionalization of smooth surfaces affected initial fibroblast morphogenesis, whereas osteoblast morphology on rough surfaces was mainly influenced by topography. The plasma- and topography-induced differential cell morphologies were however not strong enough to trigger a change in proliferation behaviour. Hence, the results indicate that oxygen plasma-functionalization represents a possible cytocompatible implant surface modification method which can be applied for tailoring implant surface wettability.

In this second part of our systematic review on the research area of 3D cell culture in micro-bioreactors we give a detailed description of the published work with regard to the existing micro-bioreactor types and their applications, and highlight important results gathered with the respective systems. As an interesting detail, we found that micro-bioreactors have already been used in SARS-CoV research prior to the SARS-CoV2 pandemic. As our literature research revealed a variety of 3D cell culture configurations in the examined bioreactor systems, we defined in review part one “complexity levels” by means of the corresponding 3D cell culture techniques applied in the systems. The definition of the complexity is thereby based on the knowledge that the spatial distribution of cell-extracellular matrix interactions and the spatial distribution of homologous and heterologous cell–cell contacts play an important role in modulating cell functions. Because at least one of these parameters can be assigned to the 3D cell culture techniques discussed in the present review, we structured the studies according to the complexity levels applied in the MBR systems.

Current research on surface modifications has yielded advanced implant biomaterials. Various implant surface modifications have been shown to be promising in improving bone target cell response, but more comprehensive studies whether certain implant surface modifications can directly target cell behavioural features such as morphogenesis and proliferation are needed. Here, we studied the response of primary alveolar bone cells on various implant surface modifications in terms of osteoblast morphology and proliferation in vitro. Analyses of surface modifications led to surface-related test parameters including the topographical parameters micro-roughness, texture aspect and surface enlargement as well as the physicochemical parameter surface wettability. We compared osteoblast morphology and proliferation towards the above-mentioned parameters and found that texture aspect and surface enlargement but not surface roughness or wettability exhibited significant impact on osteoblast morphology and proliferation. Detailed analysis revealed osteoblast proliferation as a function of cell morphology, substantiated by an osteoblast size- and morphology-dependent increase in mitotic activity. These findings show that implant surface topography controls cell behavioural morphology and subsequently cell proliferation, thereby opening the road for cell instructive biomaterials.

Bioreactors have proven useful for a vast amount of applications. Besides classical large-scale bioreactors and fermenters for prokaryotic and eukaryotic organisms, micro-bioreactors, as specialized bioreactor systems, have become an invaluable tool for mammalian 3D cell cultures. In this systematic review we analyze the literature in the field of eukaryotic 3D cell culture in micro-bioreactors within the last 20 years. For this, we define complexity levels with regard to the cellular 3D microenvironment concerning cell–matrix-contact, cell–cell-contact and the number of different cell types present at the same time. Moreover, we examine the data with regard to the micro-bioreactor design including mode of cell stimulation/nutrient supply and materials used for the micro-bioreactors, the corresponding 3D cell culture techniques and the related cellular microenvironment, the cell types and in vitro models used. As a data source we used the National Library of Medicine and analyzed the studies published from 2000 to 2020.

In our previous study, we revealed significant differences of osteopontin (OPN) gene expression in primary human osteoblasts (HOBs) derived from iliac crest bone (iHOBs) and alveolar bone (aHOBs). The present study aims at assigning this discriminative expression to a possible biologic function. OPN is known to be involved in several pathologic and physiologic processes, among others angiogenesis. Therefore, we studied the reaction of human umbilical vein endothelial cells (HUVECs) to HOB-derived OPN regarding angiogenesis. To this end, human primary explant cultures of both bone entities from ten donors were established. Subsequent transcription analysis detected higher gene expression of OPN in iHOBs compared to aHOBs, thereby confirming the results of our previous study. This difference was particularly apparent when cultures were derived from female donors. Hence, OPN protein expression as well as the angiogenic potential of OPN was analyzed, originating from HOBs of one female donor. In accordance to the gene expression level, secreted OPN was more abundant in the supernatant of iHOBs than in aHOBs. Moreover, secreted OPN was found to stimulate migration of HUVECs, but not proliferation or tube formation. These results indicate an involvement in very early stages of angiogenesis and a functional distinction of OPN from HOBs derived from different bone entities.

Objectives. Because processed allogenic bone blocks contain remnants of cells and other organic material, the present study examined the putative presence of major histocompatibility complex (MHC) molecules in protein extracts derived from processed allogeneic bone blocks. Study Design. Protein content and the immunogenic potential of 3 different processed allografts (Osteograft, DIZG, Berlin, Germany; Caput femoris, DIZG, Berlin, Germany; Human Spongiosa, Charite Tissue Bank, Berlin, Germany) were assessed by protein extraction and analysis of the presence of MHC class 1 and 2 molecules prior to grafting. MHC concentration was measured by using enzyme-linked immunosorbent assay. Results. Protein content in the allograft materials varied between 0.87 and 1.61 mu g protein/mg. In the allograft Human Spongiosa, no MHC was detected, whereas in the allogeneic bone blocks Osteograft and Caput femoris MHC 1 (0.04-0.037 ng/mg graft material) and in Osteograft MHC class 2 molecules were detectable. Conclusions. the results of the present study suggest that despite thorough processing, a potential antigenicity of allografts is not eliminated. MHC molecules in allografts may sensitize the immune system.

The development of long‐lasting zirconia‐based ceramics for implants, which are not prone to hydrothermal aging, is not satisfactorily solved. Therefore, this study is conceived as an overall evaluation screening of novel ceria‐stabilized zirconia–alumina–aluminate composite ceramics (ZA 8 Sr 8 ‐Ce11) with different surface topographies for use in clinical applications. Ceria‐stabilized zirconia is chosen as the matrix for the composite material, due to its lower susceptibility to aging than yttria‐stabilized zirconia (3Y‐TZP). This assessment is carried out on three preclinical investigation levels, indicating an overall biocompatibility of ceria‐stabilized zirconia‐based ceramics, both in vitro and in vivo. Long‐term attachment and mineralized extracellular matrix (ECM) deposition of primary osteoblasts are the most distinct on porous ZA 8 Sr 8 ‐Ce11 p surfaces, while ECM attachment on 3Y‐TZP and ZA 8 Sr 8 ‐Ce11 with compact surface texture is poor. In this regard, the animal study confirms the porous ZA 8 Sr 8 ‐Ce11 p to be the most favorable material, showing the highest bone‐to‐implant contact values and implant stability post implantation in comparison with control groups. Moreover, the microbiological evaluation reveals no favoritism of biofilm formation on the porous ZA 8 Sr 8 ‐Ce11 p when compared to a smooth control surface. Hence, together with the in vitro in vivo assessment analogy, the promising clinical potential of this novel ZA 8 Sr 8 ‐Ce11 as an implant material is demonstrated.

Objective. To adequately address clinically important issues such as osseointegration and soft tissue integration, we screened for the direct biological cell response by culturing human osteoblasts and gingival fibroblasts on novel zirconia-based dental implant biomaterials and subjecting them to transcriptional analysis.Methods. Biomaterials used for osteoblasts involved micro-roughened surfaces made of a new type of ceria-stabilized zirconia composite with two different topographies, zirco-nium dioxide, and yttria-stabilized zirconia (control). For fibroblasts smooth ceria-and yttria-stabilized zirconia surface were used. The expression of 90 issue-relevant genes was determined on mRNA transcription level by real-time PCR Array technology after growth periods of 1 and 7 days.Results. Generally, modulation of gene transcription exhibited a dual dependence, first by time and second by the biomaterial, whereas biomaterial-triggered changes were pre dominantly caused by the biomaterials' chemistry rather than surface topography. Per se, modulated genes assigned to regenerative tissue processes such as fracture healing and wound healing and in detail included colony stimulating factors (CSF2 and CSF3), growth factors, which regulate bone matrix properties (e.g. BMP3 and TGFB1), osteogenic BMPs (BMP2/4/6/7) and transcription factors (RUNX2 and SP7), matrix collagens and osteocalcin, laminins as well as integrin 1 and MMP-Significance. With respect to the biomaterials under study, the screening showed that a new zirconia-based composite stabilized with ceria may be promising to provide clinically desired periodontal tissue integration. Moreover, by detecting biomarkers modulated in a time-and/or biomaterial-dependent manner, we identified candidate genes for the targeted analysis of cell-implant bioresponse during biomaterial research and development. (C) 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

As information on osteoblast mechanosensitivity response to biomechanical cues in three-dimensional (3D) in vitro microenvironments is sparse, the present study compared morphogenesis of primary human alveolar bone osteoblasts (PHABO) under microchip-based 3D-static conditions, and 3D-fluid flow-mediated biomechanical stimulation in perfusion bioreactors. Discrimination of the respective microenvironment by differential morphogenesis was evident from fluid flow-induced PHABO reorganization into rotund bony microtissue, comprising more densely packed multicellular 3D-aggregates, while viability of microtissues was flow rate dependent. Time-lapse microscopy and simple modeling of biomechanical conditions revealed that physiologically relevant fluid flow-mediated PHABO stimulation was associated with formation of mulberry-like PHABO aggregates within the first 24 h. Differential extracellular matrix deposition patterns and gene expression modulation in PHABO aggregates at day 7 further indicates progressive osteoblast differentiation exclusively in perfusion culture-developed bony microtissues. The results of our study strongly suggest PHABO morphogenesis as discriminator of microenvironmental growth conditions, which in case of the microfluidic 3D microchip-bioreactor are substantiated by triggering in vitro bone microtissue formation concomitant with progressive osteoblastic differentiation. Such microtissue outcomes provide unique insight for mechanobiological studies in response to biomechanical fluid flow cues, and clinically appear promising for in vitro PHABO preconditioning, enabling innovative bone augmentation procedures.