SLA Titanium Surfaces Research Articles

Layer-by-layer self-assembly of PLL/CPP-ACP multilayer on SLA titanium surface: Enhancing osseointegration and antibacterial activity in vitro and in vivo

Dental Implants are expected to possess both excellent osteointegration and antibacterial activity because poor osseointegration and infection are two major causes of titanium implant failure. In this study, we constructed layer-by-layer self-assembly films consisting of anionic casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) and cationic poly (L-lysine) (PLL) on sandblasted and acid etched (SLA) titanium surfaces and evaluated their osseointegration and antibacterial performance in vitro and in vivo. The surface properties were examined, including microstructure, elemental composition, wettability, and Ca2+ ion release. The impact the surfaces had on the adhesion, proliferation and differentiation abilities of MC3T3-E1 cells were investigated, as well as the material’s antibacterial performance after exposure to the oral microorganisms such as Porphyromonas gingivalis (P. g) and Actinobacillus actinomycetemcomitans (A. a). For the in vivo studies, SLA and Ti (PLL/CA-3.0)10 implants were inserted into the extraction socket immediately after extracting the rabbit mandibular anterior teeth with or without exposure to mixed bacteria solution (P. g & A. a). Three rabbits in each group were sacrificed to collect samples at 2, 4, and 6 weeks of post-implantation, respectively. Radiographic and histomorphometry examinations were performed to evaluate the implant osseointegration. The modified titanium surfaces were successfully prepared and appeared as a compact nano-structure with high hydrophilicity. In particular, the Ti (PLL/CA-3.0)10 surface was able to continuously release Ca2+ ions. From the in vitro and in vivo studies, the modified titanium surfaces expressed enhanced osteogenic and antibacterial properties. Hence, the PLL/CPP-ACP multilayer coating on titanium surfaces was constructed via a layer-by-layer self-assembly technology, possibly improving the biofunctionalization of Ti-based dental implants.

Use of Various UVC Photofunctionalization Times to Modify Surface Characteristics and Enhance the Biologic Activity of SLA Titanium.

To evaluate the effect of ultraviolet-C light (UVC) photofunctionalization treatment time on the biologic activity of airborne particle-abraded and acid-etched (SLA) titanium surfaces and to analyze its physical and chemical mechanisms. SLA titanium was treated with UVC light for different lengths of time (10 minutes, 20 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours), and then changes to its surface characteristics were evaluated via electron microscope scanning, X-ray photoelectron spectroscopy (XPS), water contact angle measurement, and zeta potential measurement. The effect of UVC photofunctionalization on the biologic processes of SLA titanium surfaces was assessed by analyzing the bovine serum albumin adsorption, adhesion, proliferation, morphology, and alkaline phosphatase activity of MG-63 cells. UVC irradiation did not change the topography of SLA titanium surfaces. As treatment times increased, the water contact angle decreased from 120 degrees to 0 degrees, and the hydrocarbon content decreased. Zeta potential testing showed increased surface potential of photofunctionalized titanium. In vitro testing showed that cell adhesion, proliferation, morphology, and alkaline phosphate (ALP) activity on titanium surfaces were significantly improved by UVC photofunctionalization. UVC photofunctionalization can improve the biologic activity of SLA titanium surfaces by removing hydrocarbons and increasing the surface potential of titanium.

Disinfection and Biocompatibility of Titanium Surfaces Treated with Glycine Powder Airflow and Triple Antibiotic Mixture: An In Vitro Study.

The aim of this in vitro study was to compare three disinfection protocols of biofilm-coated machined (MAC) and acid etched (SLA) commercial pure Grade 4 Titanium disks. Samples were infected with a vial of polymicrobial biofilm to simulate peri-implantitis in vitro. Seventeen MAC and twenty SLA titanium disks were randomly assigned to: (1) glycine powder air-flow (GYPAP) for 1 min; (2) a local delivered triple paste antibiotic composed by a gel mixture with ciprofloxacin, metronidazole, and clarithromycin (3MIX) for 1 h; and (3) a combination of both (GYPAP + 3MIX). Biocompatibility of the titanium disks after each treatment protocol was assessed by measurement of adhesion and growth of adipose-derived mesenchymal stem cells (ASCs) after 24 and 72 h. A confocal laser scanning microscope (CLSM) assessed the antibacterial effect of each treatment. Data of the antibacterial efficacy and cell viability were presented as mean with standard deviation and calculated by one-way ANOVA with multiple comparisons via Bonferroni tests. Results were considered significant with p < 0.05. The higher cell viability was achieved by the 3MIX and GYPAP combination on the SLA surfaces after 72 h. CLSM analysis showed a mean ratio of dead bacteria statistically higher in the 3MIX + GYPAP group compared with the GYPAP and 3MIX subgroups (p < 0.05). In conclusion, data showed that the combination of GYPAP and 3MIX could be preferred to the other protocols, especially in presence of SLA titanium surface.

Nanoscale Modification of Titanium Implants Improves Behaviors of Bone Mesenchymal Stem Cells and Osteogenesis In Vivo.

The surficial micro/nanotopography and physiochemical properties of titanium implants are essential for osteogenesis. However, these surface characters' influence on stem cell behaviors and osteogenesis is still not fully understood. In this study, titanium implants with different surface roughness, nanostructure, and wettability were fabricated by further nanoscale modification of sandblasted and acid-etched titanium (SLA: sandblasted and acid-etched) by H2O2 treatment (hSLAs: H2O2 treated SLA). The rat bone mesenchymal stem cells (rBMSCs: rat bone mesenchymal stem cells) are cultured on SLA and hSLA surfaces, and the cell behaviors of attachment, spreading, proliferation, and osteogenic differentiation are further analyzed. Measurements of surface characteristics show hSLA surface is equipped with nanoscale pores on microcavities and appeared to be hydrophilic. In vitro cell studies demonstrated that the hSLA titanium significantly enhances cell response to attachment, spreading, and proliferation. The hSLAs with proper degree of H2O2 etching (h1SLA: treating SLA with H2O2 for 1 hour) harvest the best improvement of differentiation of rBMSCs. Finally, the osteogenesis in beagle dogs was tested, and the h1SLA implants perform much better bone formation than SLA implants. These results indicate that the nanoscale modification of SLA titanium surface endowing nanostructures, roughness, and wettability could significantly improve the behaviors of bone mesenchymal stem cells and osteogenesis on the scaffold surface. These nanoscale modified SLA titanium scaffolds, fabricated in our study with enhanced cell affinity and osteogenesis, had great potential for implant dentistry.

The in vitro efficacy of biofilm removal from titanium surfaces using Er:YAG laser: Comparison of treatment protocols and ablation parameters.

The aims of the present study were to compare the antibacterial effect of Er:YAG laser with other acceptable decontamination methods and to single out the optimal laser device parameters for effective bacterial elimination. A multispecies biofilm which was composed of Streptococcus sanguis, Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum was grown on sandblasted and acid-etched (SLA, homogeneous moderately microrough, and nanosmooth surface) titanium disks. The biofilm was removed from the coated disks by hand curets, ultrasonic device, nylon brush (dental polishing prophy cup), or Er:YAG. Additionally, different parameter combinations of the laser machine were examined to reach an optimal lasing power for bacterial elimination/reduction. Residual biofilm samples were stained with bacterial live/dead staining and quantified using a fluorescent microscope. A multispecies biofilm was accumulated on the SLA titanium surfaces exhibiting cluster distribution next to bacteria-poor areas. Hand curets, nylon brushes, and the ultrasonic device showed limited capability to effectively remove the biofilm from the SLA surfaces as opposed to the Er:YAG which displayed a superior ability to remove the biofilm. All Er:YAG parameter combinations that were evaluated as well as the tested "tip to target" distances showed similar excellent anti-biofilm effects. Furthermore, we observed that the Er:YAG capability of biofilm removal is not only due to its light emission, but depends on its water irrigation as well. Er:YAG laser has an excellent biofilm removal capability compared with hand curets, ultrasonic devices, or nylon brushes even when low energy parameters and low power settings are used. Additionally, an excellent antibacterial effect can be reached using a non-contact mode of 1 to 5mm "tip to target" distance.

Surface characteristics and osteocompatibility of titanium preserved in a ZnS@BSA-containing storage solution

This study aimed to the preparation of a storage solution containing zinc sulfide particles encapsulated in bovine serum albumin (ZnS@BSA) and its application to improve surface characteristics and osteocompatibility of pure and SLA titanium surfaces. The analysis of surface characteristics including surface topography, elemental distribution and protein amounts confirmed that ZnS@BSA particles were successfully adsorbed on the two titanium surfaces without changing the original morphology. Assays of wettability showed that titanium surfaces preserved in ZnS@BSA solution had superior hydrophilicity compared with control groups. In vitro experiments demonstrated that the titanium surfaces preserved in ZnS@BSA solution significantly promoted the proliferation, adhesion and differentiation of MC3T3-E1 cells. The study therefore concluded that the ZnS@BSA solution could improve the bioactivity of titanium surface and exhibit the potential to be a new type of titanium implant storage solution.

Decontamination of rough implant surfaces colonized by multispecies oral biofilm by application of leukocyte- and platelet-rich fibrin.

Decontamination of biofilm-infected rough implant surfaces is challenging. Platelet rich blood products have been shown to have anti-microbial properties against periodontal pathogens. Our aim was to investigate the effect of a potential biological implant surface disinfectant, leukocyte- and platelet-rich fibrin (L-PRF), on a mature oral multispecies biofilm on a rough titanium surface. Sandblasted, large grit, acid-etched (SLA) titanium disks were inoculated with subgingival dental plaque and cultured anaerobically for 21 days. The L-PRF membranes were collected from 12 donors in three trials (four donors in each trial). The disks were rinsed with 0.9% NaCl and exposed to the cell-rich portion of the L-PRF membranes for 48hours followed by scanning electron microscope (SEM) analysis immediately or after rinsing with 0.9% NaCl prior to fixation. The presence of platelet factor-4 in the rinse samples was analyzed by Western blotting. Remaining bacteria were quantified from SEM images of the implant surfaces and their numbers statistically compared. The L-PRF-treated samples without rinsing displayed numerous cells with multiple pseudopodia in immediate contact with bacteria that appeared perforated and increased in size. The cells were identified as platelets based on morphological criteria and by positive reaction for platelet factor-4 by Western blotting. After post-treatment rinsing, the L-PRF-treated disks displayed a significant reduction in bacterial counts (in average 92% reduction). Application of L-PRF significantly reduced bacterial counts on contaminated SLA titanium surface, most likely through anti-microbial action by platelets.

A titanium surface modified with zinc-containing nanowires: Enhancing biocompatibility and antibacterial property in vitro

This study aimed to generate a titanium surface modified with zinc-containing nanowires and explore its enhancements in both biocompatibility and antibacterial property. Acid etching was used to prepare a micro-rough titanium surface. Nanowires were then synthesized on this pre-treated microstructured surface via a treatment with a NaOH solution in a 70 °C water bath. The resultant nanowires-modified titanium surface (Ti-NW) was then subjected to a second treatment with a ZnSO4 solution in a 70 °C water bath, resulting in zinc (Zn) deposition in the nanowires. This approach yielded a modified titanium surface with Zn-containing nanowires (Ti-NW-Zn). In addition, the control titanium surface was prepared via sandblasting with large-grit and acid etching (Ti-SLA), which is commonly used for dental implants. Afterwards, the properties of these surfaces were examined, including topography, roughness, wettability, elemental composition, metallurgical phase, and Zn ion release. The abilities of adhesion, proliferation, and differentiation of MC3T3-E1 cells on these surfaces were investigated, as well as their antibacterial properties in the context of oral microorganisms of Staphylococcus aureus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans. The modified titanium surface (Ti-NW-Zn) was successfully prepared and appeared as Zn-containing nanowire networks with high hydrophilicity. The Ti-NW-Zn surface was able to continuously release Zn ions. Furthermore, the results of in vitro study showed that the Ti-NW-Zn surface up-regulated cell adhesion, proliferation, osteogenic differentiation. Meanwhile, the Ti-NW-Zn surface possessed satisfactory antibacterial effectiveness in vitro. Relative to conventional SLA titanium surface, the Zn-containing nanowires-modified titanium surface exhibited significant improvements in both osteocompatibility and antibacterial activity against oral microorganisms.

Biocorrosion of pure and SLA titanium surfaces in the presence of Porphyromonas gingivalis and its effects on osteoblast behavior

Objective: The study aims to investigate the biocorrosion behavior of Porphyromonas gingivalis on pure and SLA titanium surfaces and its effects on surface characteristics and osteoblast behavior. Methods: Pure and SLA titanium specimens were immersed in culture medium with P. gingivalis and incubated for 7 days. P. gingivalis colonization on the pure and SLA titanium surfaces was observed by scanning electron microscopy (SEM). The pure and SLA titanium surface characteristics were analyzed via X-ray photoelectron spectroscopy (XPS), surface roughness and surface wettability. The corrosion behaviors of pure and SLA titanium specimens were evaluated by electrochemical corrosion test. The osteoblast behavior of MC3T3-E1 cells on the pure and SLA titanium surfaces after P. gingivalis colonization was investigated by cell adhesion and western blot assays. Results: P. gingivalis colonized on the pure and SLA titanium surfaces was observed by SEM. The XPS analysis demonstrated reductions in the relative levels of titanium and oxygen and obvious reductions of dominant titanium dioxide (TiO2) on both titanium surfaces after immersing the metal in P. gingivalis culture. In addition, their roughness and wettability were changed. Correspondingly, the electrochemical corrosion test results revealed significant decreases in the corrosion resistance and increases in the corrosion rate of the pure and SLA titanium specimens after immersion in P. gingivalis culture. The results of the in vitro study showed that the pre-corroded pure and SLA titanium surfaces by P. gingivalis exhibited lower osteocompatibility and down-regulated the adhesion, spreading and osteogenic differentiation abilities of MC3T3-E1 cells. Conclusions: P. gingivalis was able to colonize on the pure and SLA titanium surfaces and weaken their surface properties, especially a decrease in the protective TiO2 film, which induced the biocorrosion and further negatively affected the osteoblast behavior.

Integrated analysis of lncRNA-mRNA networks associated with an SLA titanium surface reveals the potential role of HIF1A-AS1 in bone remodeling.

Microstructured titanium surface implants, such as typical sandblasted and acid-etched (SLA) titanium implants, are widely used to promote bone apposition in prosthetic treatment by dental implants following tooth loss. Although there are multiple factors associated with the superior osseointegration of an SLA titanium surface, the molecular mechanisms of long noncoding RNAs (lncRNAs) are still unclear. In this study, we characterized smooth (SMO) and SLA surfaces, and compared the osteoinduction of these surfaces using human bone marrow-derived mesenchymal stem cells (hBMSCs) in vitro and implants in a rat model in vivo. Then, we used microarrays and bioinformatics analysis to investigate the differential expression profiles of mRNAs and lncRNAs on SMO and SLA titanium surfaces. An lncRNA–mRNA network was constructed, which showed an interaction between lncRNA HIF1A antisense RNA 1 (HIF1A-AS1) and vascular endothelial growth factor. We further found that knockdown of HIF1A-AS1 significantly decreased osteogenic differentiation of hBMSCs. This study screened SLA-induced lncRNAs using a systemic strategy and showed that lncRNA HIF1A-AS1 plays a role in promotion of new bone formation in the peri-implant area, providing a novel insight for future surface modifications of implants.

Influence of bio-aging on corrosion behavior of different implant materials.

Dental implants and abutments are exposed to challenging oral environment. Corrosion of these materials can affect the overall performance of titanium implants. To investigate the effects of biofilm-induced bio-aging on corrosion behavior of different implant materials surface. Commercial polished titanium (Polish), sand-blasted, large grit, acid-etched surface treated titanium (SLA), microarc oxidation (MAO), and hydroxyapatite (HA) coated titanium were bio-aged with saliva biofilm for 30 days. Titanium surfaces topography, chemical composition, roughness, and water contact angle changes were evaluated. In addition, human gingival fibroblasts (HGFs) adhesion, Streptococcus sanguinis (S. sanguinis) biofilm formation were determined. Surface topography, roughness, and chemical composition have no significant changes for all groups after bio-aging (P > .05). Water contact angle of bio-aged SLA was greatly increased (P < .05). While other groups showed no sign of change (P > .05). Adhesion and proliferation of HGFs on the bio-aged SLA titanium surfaces were decreased (P < .05), but increased on bio-aged Polish and HA titanium (P < .05). S. sanguinis biofilm viability was promoted with bio-aging in HA group (P < .05). Biological characteristics of Polish, SLA, and HA titanium surfaces were influenced by bio-aging. While MAO group was relatively resistant to saliva biofilm bio-aging.

Similar inductive effects of enamel and dentin matrix derivatives on osteoblast-like cell response over SLA titanium surface

ObjectivesThe aim of this in vitro study was to investigate the behavior of osteoblasts on titanium discs under different concentrations of enamel matrix derivatives (EMD) and dentin matrix derivative (DMD). Materials and methodsMC3T3-E1 osteoblast-like cells were cultivated on coated titanium SLA discs with EMD or DMD at 100 μg/ml, 1 mg/ml, 10 mg/ml and 30 mg/ml or left uncoated. Cell viability, proliferation, adhesion and migration were assessed respectively with MTT, BrdU, DAPI and scratch wound healing assays. Messenger ribonucleic acid of different genes related to osteoblastic differentiation was quantified by means of real-time quantitative PCR. Data were analyzed using student t-test for adhesion and migration assay and ANOVA for proliferation assay (p < 0.05). ResultsBrdU incorporation was found in proliferative osteoblasts for both test solutions at all concentrations. Osteoblast migrated and covered approximately 70% of the wound area observed at time zero when exposed to EMD and DMD to all concentrations. The increase of gene expression was dependent on the concentration enhancement of EMD and DMD. Higher concentrations showed proliferation augmentation if compared to lower concentrations. ConclusionsRoughness surface of Ti SLA can limit cell adhesion independent of the presence EMD or DMD. DMD enhances cell migration of osteoblasts on SLA titanium implants in a concentration-dependent manner.

LncRNAs Transcriptome Analysis Revealed HIF1A-AS1 as a Mediator of Bone Remodeling Associated with the Micro Structured Titanium Surface

Because of their hierarchical structure, sandblasted and acid etched (SLA) titanium implants are widely used to promote bone apposition. Understanding the molecular mechanisms of SLA titanium implant-enhanced osteogenesis provides clues to improve surface modification methods. However, the epigenetics mechanisms involving SLA surface weren't clear. In this study, we systematically identify the long noncoding RNAs (lncRNAs) and mRNAs related to the superior osseointegration induced by SLA. The mechanical, chemical, and osteogenic characteristics of the fabricated SLA and smooth polished (SMO) titanium surfaces were compared and analyzed. Thousands of lncRNAs and mRNAs within osteogenesis-associated biological processes were differentially expressed in human bone marrow-derived mesenchymal stem cells (hBMSCs) on SLA surface compared with SMO surface. We constructed an mRNA-lncRNA co-expression network to gain insight into the role of differentially expressed lncRNAs and validated the co-expression of HIF1A-AS1/VEGFA, IGF2-AS/GLI2, and HOXD-AS1/FGF10. Further, we identified that the knockdown of HIF1A-AS1 not only decreased the expression of VEGFA, but also significantly inhibited the osteogenic differentiation of hBMSCs. Meanwhile, we found that silencing of lncRNA HIF1A-AS1 reduced the level of phosphorylated mitogen-activated protein kinase (p-MAPK). In conclusion, our study indicated that the SLA surface enhanced osteogenesis partly through differential regulation of lncRNAs, like HIF1A-AS1. Our study also increased the understanding of the role lncRNA HIF1A-AS1 in the differentiation of osteoblast, providing clues for the potential optimization of titanium implant surface.

The interactions of dendritic cells with osteoblasts on titanium surfaces: an in vitro investigation.

Osteoimmune interactions possess a critical part in the integration of materials and hosts. Dendritic cells (DCs) are the most common members of osteoimmune cells family. The titanium surfaces of dental implants tend to promote a mature dendritic cell phenotype with increased proinflammatory secretion. However, very little is known to the effects of this microenvironment on the behaviors of cells around implants, especially osteoblasts, and how the tissue integrations take place on such biomaterial surfaces. Therefore, the present study was to investigate the interactions of DCs with osteoblasts on titanium surfaces. DCs seeded on PT and SLA titanium surfaces were compared by assays for the proliferations, surface markers, and inflammatory genes expressions. DCs seeded on PT and SLA titanium surfaces were compared by assays for the proliferations, surface markers, and inflammatory genes expressions. Next, we harvested the dendritic cell-conditioned medium (CM) and investigated the effects of CM on MC3T3-E1. The results showed an increase in CD86 and proinflammatory expressions of DCs seeded on PT and SLA surfaces, as well as a decrease in anti-inflammatory cytokines. The CM from titanium surfaces inhibited the osteoblast differentiation with reduced expression of osteogenic genes RUNX2, COL1, ALP, and OCN and decreased ALP activity as well as Alizarin red staining. These findings suggested that titanium surfaces switch DCs toward maturation phenotypes and thus inhibit the differentiation and mineralization of osteoblasts. Knowing the significant impact of immune cells on osteogenesis behaviors, some efforts to decrease the immune reaction might be of clinical significance. Favorable immune environments can increase the dental implants survival rate in patients.

Impact of Nano-Crystalline Diamond Enhanced Hydrophilicity on Cell Proliferation on Machined and SLA Titanium Surfaces: An In-Vivo Study in Rodents.

By coating surfaces with nano-crystalline diamond (NCD) particles, hydrophilicity can be altered via sidechain modifications without affecting surface texture. The present study aimed to assess the impact of NCD hydrophilicity on machined and rough SLA titanium discs on soft tissue integration, using a rodent model simulating submerged healing. Four different titanium discs (machined titanium = M Titanium, NCD-coated hydrophilic machined titanium = M-O-NCD, sand blasted acid etched (SLA Titanium) titanium, and hydrophilic NCD-coated SLA titanium = SLA O-NCD) were inserted in subdermal pockets of 12 Wistar rats. After one and four weeks of healing, the animals were sacrificed. Biopsies were embedded in methyl methacrylate (MMA), and processed for histology. The number of cells located within a region of interest (ROI) of 10 µm around the discs were counted and compared statistically. Signs of inflammation were evaluated descriptively employing immunohistochemistry. At one week, M-O-NCD coated titanium discs showed significantly higher amounts of cells compared to M Titanium, SLA Titanium, and SLA-O-NCD (p < 0.001). At four weeks, significant higher cell counts were noted at SLA-O-NCD surfaces (p < 0.01). Immunohistochemistry revealed decreased inflammatory responses at hydrophilic surfaces. Within the limits of an animal study, M-O-NCD surfaces seem to stimulate cell proliferation in the initial healing phase, whereas SLA-O-NCD surfaces appeared advantageous afterwards.

PR569: Effect of enamel matrix derivative and dentin matrix protein on osteoblastic proliferation and adhesion over SLA titanium surface

PR569: Effect of enamel matrix derivative and dentin matrix protein on osteoblastic proliferation and adhesion over SLA titanium surface

Superiority of calcium-containing nanowires modified titanium surface compared with SLA titanium surface in biological behavior of osteoblasts: A pilot study

ObjectiveThe aim of this study was to present a procedure of preparing calcium-containing nanowires on pretreated micro-structured titanium substrate and explore the superiority of this modified titanium surface compared with SLA titanium surface in biological behavior of osteoblasts. Materials and methodsIn this study, micro-structured titanium substrate was prepared via acid etching. Through hydrothermal treatment with a NaOH solution, nanowires were synthesized on the pretreated micro-structured titanium substrate to prepare the nanowires modified titanium surface (Ti-NW). Then, the Na+ existing in the nanowires was replaced by Ca2+ through secondary hydrothermal treatment with a CaCl2 solution to prepare the calcium-containing nanowires modified titanium surface (Ti-NW-Ca). The sandblasting and acid etching (SLA) titanium surface, which was most commonly used for clinical oral implants, was prepared as the control group. Physical properties of different titanium surfaces including topography, elemental composition, surface roughness and wettability were measured. Assays of spreading, proliferation and differentiation abilities of MC3T3-E1 cells on different titanium surfaces were investigated as well. ResultsThe modified titanium surface was successfully prepared and appeared as calcium-containing nanowire networks, which revealed excellent hydrophilicity and could sustainedly release Ca ions into phosphate buffer saline. The results of in vitro study showed that the Ti-NW-Ca surface had satisfactory osteocompatibility and upregulated the cell spreading, proliferation and differentiation in comparison with the SLA titanium surface. ConclusionsCompared with the SLA titanium surface, the calcium-containing nanowires modified titanium surface demonstrated the ability to enhance osteoblast behavior and suggested the potential to accelerate the dental implant osseointegration.

Response to antiseptic agents of periodontal pathogens in in vitro biofilms on titanium and zirconium surfaces

ObjectiveThe aim of this study was to develop in vitro biofilms on SLA titanium (Ti-SLA) and zirconium oxide (ZrO2) surfaces and to evaluate the effect of antiseptic agents on the number of putative periodontal pathogenic species. MethodsAn in vitro biofilm model was developed on sterile discs of Ti-SLA and ZrO2. Three antiseptic agents [chlorhexidine and cetyl-pyridinium-chloride (CHX/CPC), essential oils (EEOOs) and cetyl-peridinium-chloride (CPC)] were applied to 72-h biofilms, immersing discs during 1min in the antiseptic solution, either with or without mechanical disruption. Viable bacteria [colony forming units (CFU/mL)] were measured by quantitative polymerase chain reaction (qPCR) combined with propidium monoazide. A generalized lineal model was constructed to determine the effect of the agents on the viable bacterial counts of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum on each surface. ResultsThe exposure to each antiseptic solution resulted in a statistically significant reductions in the number of viable target species included in the in vitro multi-species biofilm, on both Ti-SLA and ZrO2 (p<0.001) which was of up to 2 orders for A. actinomycetemcomitans, for P. gingivalis 2 orders on Ti-SLA and up to 3 orders on ZrO2, and, for F. nucleatum up to 4 orders. No significant differences were found in counts of the tested bacteria between in vitro biofilms formed on both Ti-SLA and ZrO2, after topically exposure to the antimicrobial agents whether the application was purely chemical or combined with mechanical disruption. SignificanceA. actinomycetemcomitans, P. gingivalis and F. nucleatum responded similarly to their exposure to antiseptics when grown in multispecies biofilms on titanium and zirconium surfaces, in spite of the described structural differences between these bacterial communities.

Effects of Titanium Surface Microtopography and Simvastatin on Growth and Osteogenic Differentiation of Human Mesenchymal Stem Cells in Estrogen-Deprived Cell Culture.

This study aimed to investigate the effects of titanium surface topography and simvastatin on growth and osteogenic differentiation of human bone marrow stromal cells (hBMSCs) in estrogen-deprived (ED) cell culture. Human BMSCs were seeded on cell culture plates, smooth-surface titanium (Ti) disks, and sandblasted with large grits and acid etched (SLA)-surface Ti disks; and subsequently cultured in regular (fetal bovine serum [FBS]), ED, and ED-with 100 nM simvastatin (ED-SIM) culture media for 14 to 21 days. Live/dead cell staining, scanning electron microscope examination, and cell viability assay were performed to determine cell attachment, morphology, and growth. Expression levels of osteoblast-associated genes, Runx2 and bone sialoprotein and levels of alkaline phosphatase (ALP) activity, calcium content, and osteocalcin in culture media were measured to determine osteoblastic differentiation. Expression levels of bone morphogenetic protein-2 (BMP-2) were investigated to examine stimulating effects of simvastatin (n = 4 to 5, mean ± SD). In vitro mineralization was verified by calcein staining. Human BMSCs exhibited different attachment and shapes on smooth and SLA titanium surfaces. Estrogen-deprived cell culture decreased cell attachment and growth, particularly on the SLA titanium surface, but cells were able to grow to reach confluence on day 21 in the ED-osteogenic (OS) culture medium. Promoting effects of the SLA titanium surface in ED-OS were significantly decreased. Simvastatin significantly increased osteogenic differentiation of human BMSCs on the SLA titanium surface in the ED-OS medium, and the promoting effects of simvastatin corresponded with the increasing of BMP-2 gene expression on the SLA titanium surface in ED-OS-SIM culture medium. The ED cell culture model provided a well-defined platform for investigating the effects of hormones and growth factors on cells and titanium surface interaction. Titanium, the SLA surface, and simvastatin synergistically promoted osteoblastic differentiation of hBMSCs in ED condition and might be useful to promote osteointegration in osteoporotic bone.

Modification of a SLA titanium surface with calcium-containing nanosheets and its effects on osteoblast behavior

The aim of this study was to present a procedure to prepare a calcium-containing nanosheets-modified sandblasted and acid etched (SLA) titanium surface and explore its effects on osteoblast behavior.