Sandblasted Titanium Disks Research Articles

S. aureus develops biofilms on titanium within 2 weeks in vitro.

The formation of biofilms, characterized by cell aggregation and extracellular polymeric substance (EPS) production, is a common feature of periprosthetic joint infections (PJI). The current study aimed to investigate the development of biofilm features in vitro within less than 3 weeks by Staphylococcus aureus isolated from PJIs. Biofilms were grown on sandblasted titanium discs, and fluorescence spectroscopy and microscopy were used to observe biofilm maturation for 21 days. DNA mass decreased initially, then increased from day 5 onwards, and decreased again after day 7. The proportion of living to dead bacteria oscillated until day 7 and increased at day 10 for strain A and day 14 for strain B. EPS mass decreased initially and then continuously increased. Multilayer bacterial organization was observed at day 7. Cell aggregation occurred during the first week, followed by EPS production in the second week, and characteristic biofilm features were observed within 1 to 2 weeks.

Comparative Evaluation of the Osteogenic Potential of Titanium Discs Subjected to Argon Plasma Surface Treatment: An in vitro Study

Abstract Introduction: Titanium is the most widely used material for dental implants; however, its biological aging can lead to a decreased rate of osseointegration. Titanium surfaces on exposure to argon plasma possess a hydrophilic surface that increases the biological activity of osteoblasts on the implant surface. Hence, this in vitro study was undertaken to assess and compare the osteogenic potential and proliferative nature of osteoblast-like cells on titanium when subjected to argon plasma surface treatment. Materials and Methods: A total of 108 titanium discs (10 mm × 2 mm ASTM B348) were included in the study, and their surface topography was characterized. The test specimens were divided into two subgroups based on surface treatments used, i.e. the study group (n = 54): titanium discs treated with argon plasma and the control group (n = 54): sandblasted titanium discs. The osteogenic potential of the specimens was evaluated by assessing the cell attachment using a hemocytometer and cell proliferation using an MTT assay on MG-63 cell lines at three different time intervals of 24, 48, and 72 h. Results: The cell attachment and cell proliferation values were statistically significant (P = 0.001*). In comparison to the control group, these two parameters were considerably greater in the plasma-treated group. The total effect size of the study group was 85% as opposed to 35% of the control group. Conclusion: Argon plasma surface treatment had a positive effect on the cellular events of MG-63 cells which can be thought of as an added advantage along with the decontamination procedure for titanium to help in the process of osseointegration.

A comparison of human dental pulp stem cell activity cultured on sandblasted titanium discs decontaminated with Er:YAG laser and air-powder abrasion: an in vitro study.

Decontamination of implant surfaces is important to the treatment of peri-implantitis. Er:YAG laser and air-powder abrasion system are regarded as the most effective means of decontamination of implant surfaces. The aim of this in vitro study was to compare the activity of human dental pulp stem cells (hDPSCs) cultured on decontaminated sandblasted titanium discs using Er:YAG laser irradiation and air-powder abrasion. Forty-five titanium discs were contaminated with Escherichia coli (E. coli) bacteria and fifteen titanium discs served as sterile control groups. Thirty contaminated titanium discs were decontaminated with Er:YAG laser or air-powder abrasion system and fifteen contaminated discs were used as contaminated control group. Afterwards, hDPSCs were seeded on all sixty experimental titanium discs. The effects of two decontamination tools on hDPSCs viability were evaluated by MTT assay. Alkaline phosphatase (ALP) activity assay, quantitative real-time PCR analysis and alizarin red staining method were performed to assess hDPSCs osteogenic differentiation. Scanning microscope electron (SEM) was also used to evaluate the effects of two different decontaminated methods on cellular morphology. Our study showed that decontamination using Er:YAG laser caused maximum cell viability. However, the ALP activity was not different in laser and air-abrasion groups. The significant expression of an osteoblastic marker and stronger Alizarin red staining were observed in laser irradiation groups. In addition, SEM observation indicated that grown cells were more stretched and more filopodia in Er:YAG-treated discs. In the present study, Er:YAG laser and air-powder abrasion improved the activity of the cells cultured on the decontaminated titanium discs. However, in comparison with air-powder abrasion, Er:YAG laser was more effective.

Effects of Two Protocols of Low-Level Laser Therapy on the Proliferation and Differentiation of Human Dental Pulp Stem Cells on Sandblasted Titanium Discs: An In Vitro Study.

Introduction: Stem cell activities have different effects on tissue response and its outcomes. Low-level laser therapy (LLLT) can be considered a trigger to modify stem cell activities. The objective of the present experimental investigation was to study the effects of two protocols of LLLT on the proliferation and differentiation of human dental pulp stem cells (hDPSCs) cultured on sandblasted titanium discs. Methods: Cells obtained from human dental pulp were seeded/cultured on titanium discs and were set in 2 main groups: (i) Radiated cells using the gallium-aluminium-arsenide (GaAlAs) diode laser at a continuous wavelength of 808 nm at 3 J/cm2 for 12 sec or 5 J/cm2 for 20 seconds, and (ii) Non-irradiated cells serving as control groups. The impact of LLLTs on hDPSC-proliferation and viability was investigated using the MTT assay after 24, 72 and 96 hours. The alkaline phosphatase activity was studied with p-nitrophenylphosphate after 14 and 28 days. The ability of hDPSCs to express osteocalcin was investigated using real-time polymerase chain reaction after 28 days, while their attachment was observed under a scanning electron microscope (SEM) after 14 and 28 days. Results: Our study showed that LLLTs caused maximum cell proliferation in 96 hours (P<0.001) with 3 J/cm2 resulting in a higher proliferation rate. The highest activity of alkaline phosphatase and osteocalcin expression was observed in the laser radiation groups after 28 days. Conclusion: The outcomes of the current study showed that cultured hDPSCs on sandblasted titanium discs had a tendency towards increased cellular activity in response to LLLTs. Thus, LLLTs could regulate the activities of hDPSCs on bone repair surrounding the sandblasted titanium discs.

Evaluation of Antimicrobial Effect of Air-Polishing Treatments and Their Influence on Human Dental Pulp Stem Cells Seeded on Titanium Disks.

Dental implants are one of the most frequently used treatment options for tooth replacement, and titanium is the metal of choice due to its demonstrated superiority in resisting corrosion, lack of allergic reactions and mechanical strength. Surface roughness of titanium implants favors the osseointegration process; nevertheless, its topography may provide a suitable substrate for bacterial biofilm deposition, causing peri-implantitis and leading to implant failure. Subgingival prophylaxis treatments with cleansing powders aimed to remove the bacterial accumulation are under investigation. Two different air-polishing powders—glycine and tagatose—were assayed for their cleaning and antimicrobial potential against a Pseudomonas biofilm and for their effects on human dental pulp stem cells (hDPSCs), seeded on sandblasted titanium disks. Immunofluorescence analyses were carried out to evaluate cell adhesion, proliferation, stemness and osteogenic differentiation. The results demonstrate that both the powders have a great in vitro cleaning potential in the early period and do not show any negative effects during hDPSCs osteogenic differentiation process, suggesting their suitability for enhancing the biocompatibility of titanium implants. Our data suggest that the evaluated cleansing systems reduce microbial contamination and allow us to propose tagatose as an adequate alternative to the gold standard glycine for the air-polishing prophylaxis treatment.

Effect of Mother’s Age and Pathology on Functional Behavior of Amniotic Mesenchymal Stromal Cells—Hints for Bone Regeneration

Human amnion-derived mesenchymal stromal cells (hAMSCs) are used increasingly in regenerative medicine applications, including dentistry. The aim of this study was to evaluate if hAMSCs from aged and pathological mothers could be affected in their phenotype and functional behavior. hAMSCs were isolated from placentas of women aged younger than 40 years (Group 1, n = 7), older than 40 years (Group 2, n = 6), and with pre-eclampsia (Group 3, n = 5). Cell yield and viability were assessed at isolation (p0). Cell proliferation was evaluated from p0 to p5. Passage 2 was used to determine the phenotype, the differentiation capacity, and the adhesion to machined and sandblasted titanium disks. hAMSCs recovered from Group 3 were fewer than in Group 1. Viability and doubling time were not different among the three groups. Percentages of CD29+ cells were significantly lower in Group 3, while percentages of CD73+ cells were significantly lower in Groups 2 and 3 as compared with Group 1. hAMSCs from Group 2 showed a significant lower differentiation capacity towards chondrogenic and osteogenic lineages. hAMSCs from Group 3 adhered less to titanium surfaces. In conclusion, pathology can affect hAMSCs in phenotype and functional behavior and may alter bone regeneration capacities.

Effect of Nonsteroidal Anti-inflammatory Drugs on the Osteogenic Activity of Osteoprogenitor Cells Cultured on Titanium Surfaces.

The purpose of this study was to investigate the effects of celecoxib and ibuprofen on the proliferation, viability, and migration of MC3T3-E1 cells cultured on titanium surfaces. MC3T3-E1 cells were cultured on sandblasted titanium disks and allocated to one of the following interventional groups: (a) control (untreated group); (b) celecoxib (5 μM and 10 μM); (c) ibuprofen (5 μM and 10 μM); and (d) prostaglandin E2 (10 μM). Proliferation of attached cells was assessed over 9 days using an AlamarBlue assay. A trypan blue exclusion test was conducted to assess cell viability, where the relative percentages of live and dead cells were quantified using a hemocytometer over 2 days. A Boyden-Chamber Assay was utilized to assess cell migration over 33 days. The proliferation of cells treated with any intervention was not significantly different than that of the untreated group throughout the treatment period. However, celecoxib and ibuprofen significantly decreased the percentage of viable cells in a dose-dependent manner. Specifically, celecoxib (10 μM) and ibuprofen (5 μM and 10 μM) on day 1, and celecoxib (10 μM) on day 2 showed significantly higher percentages of dead cells compared to the untreated cells. There was a significant increase in migration of cells treated with ibuprofen (5 μM) compared with untreated cells on day 1; however, the migration of cells treated with any of the interventions was not significantly different from that of untreated cells on day 3. Cocnclusion: Nonsteroidal anti-inflammatory drugs at therapeutic doses did not significantly affect osteoblast proliferation and migration. However, higher dosages of celecoxib (10 μM) significantly reduced the cell viability and, therefore, can potentially affect the process of osseointegration.

Erythritol/chlorhexidine combination reduces microbial biofilm and prevents its formation on titanium surfaces in vitro.

The purpose of this in vitro study was to evaluate the antibiofilm activity of a novel air-polishing powder consisting of erythritol and chlorhexidine, assessing its ability to reduce previously grown microbial biofilm and to prevent biofilm formation on titanium surfaces. Clinical strains of Staphylococcus aureus, Pseudomonas aeruginosa, Bacteroides fragilis and Candida albicans isolated from peri-implantitis lesions were used. Biofilm was grown on sandblasted titanium discs and treated with erythritol/chlorhexidine. The antimicrobial activity was evaluated by determining the minimum inhibitory concentration and the minimum microbicidal concentration. The antibiofilm activity was assessed by semiquantitative spectrophotometric assay and by confocal laser scanning microscopy. Erythritol/chlorhexidine displayed an inhibitory and a microbicidal activity against all the tested strains. The spectrophotometric analysis showed that the treatment was effective in both reducing the previously developed biofilm and decreasing biofilm formation on titanium surfaces. Confocal laser scanning microscopy analysis showed a significant reduction of the total biofilm volume, with an increase of the percentage of dead cells of all the microorganisms tested. Erythritol/chlorhexidine displayed significant antimicrobial and antibiofilm activity against microorganisms isolated from peri-implantitis lesions. Due to its properties, it might represent a promising approach for the prevention and treatment of peri-implant diseases associated to microbial biofilm infections.

The effect of laser‐treated titanium surface on human gingival fibroblast behavior

Surface modification, as a means of enhancing soft tissue integration in titanium would have significant advantages including less marginal bone resorption, predictable esthetic outcome, improved soft tissue stability, and seal against bacterial leakage. The aim of this study was to evaluate the effects of laser-roughened titanium surfaces on human gingival fibroblast (HGF) viability, proliferation, and adhesion. Titanium discs were ablated with impulse laser in four different patterns. Polished and sand-blasted titanium discs were used as control groups. Specimen surface properties were determined using optical profilometry and scanning electron microscopy. HGF behavior on modified surfaces was analyzed using cell adhesion, viability, proliferation, and ELISA assays. Results suggested that modified Ti surfaces did not affect the viability of HGFs and improved adhesion was measured in laser treatment groups after 24 h. However, proliferation study showed that the adsorbance of fibroblast cells after 72 h cultured on polished titanium was higher and comparable with that of control cells. As for focal adhesion kinase (FAK), cells grown on laser modified surfaces had higher expression of FAK as compared with polished titanium. In conclusion, tested laser-treated surfaces seem to favor HGF adhesion. There were no significant differences between different laser treatment groups.

Activity of N-acetyl-L-cysteine against Biofilm of Staphylococcus Aureus and Pseudomonas Aeruginosa on Orthopedic Prosthetic Materials

Staphylococcus aureus and Pseudomonas aeruginosa are frequently isolated from biofilm-associated orthopedic implant infections. This study assessed the activity of N-acetyl-L-cysteine at inhibitory and subinhibitory concentrations against biofilm formed by S. aureus and P. aeruginosa on prosthetic materials. S. aureus and P. aeruginosa biofilm on smooth polyethylene and sand-blasted titanium discs was determined by means of a spectrophotometric assay before and at 3, 6, and 18 hours after addition of N-acetyl-L-cysteine. N-acetyl-L-cysteine was able to disaggregate biofilm produced by S. aureus and P. aeruginosa on polyethylene and titanium discs after 3 h of incubation. A different rate in eradication of biofilm produced by P. aeruginosa was seen between polyethylene and titanium (50% vs. 20% respectively vs. biofilm formed before treatment). Results were confirmed by confocal laser scanning microscopy. The results suggest a possible role of N-acetyl-L-cysteine in the treatment of orthopedic prosthetic infections.

Effect of Laser Micromachining of Titanium on Viability and Responsiveness of Osteoblast-Like Cells

Laser engineering may create hemispherical porosities on titanium surfaces obtaining regular and predetermined rough titanium surfaces. The aim of this study was to assess the viability and the proliferation of primary osteoblast-like cells (OB) to growth factors on titanium surfaces with a different roughness in vitro. OB were obtained from volunteers undergoing wisdom tooth removal following a standardized protocol. OB were allowed to attach on 4 different titanium surfaces: sandblasted titanium (SBT) disks, 5-, 10-, and 20-μm regular laser-engineered micropore titanium disks. A well with no disk was used as control. Cell morphology was evaluated with scanning electron microscopy. Viability was measured with MTT (3[4,5 dimethylthiazol 2yl]2,5 diphenyltetrazolium bromide) assay. Proliferation rate of attached cells was evaluated with Cell Counting Kit-8 48 hours after platelet-released supernatant (PRS) application. Statistical analysiswas performed with analysis of variance test. All surfaces showed OB attachment on scanning electron microscopy. OB appeared more numerous on 20T surfaces. Laser-engineered surfaces showed higher OB viability than SBT (P < 0.01). In terms of proliferation, viability increase was noted for all groups after platelet-released supernatant application. 20T and SBT disks seemed to trigger the higher cellular proliferation (20T vs 10T, P < 0.05). Laser-engineered porous titanium surfaces promote viability and proliferation of OB. In particular, hemispherical porosity of 20 μm seems to trigger the higher OB response. Further research is needed to confirm these data.