Biological response of human bone marrow stromal cells to sandblasted titanium nitride-coated implant surfaces

Assessing the Efficacy of Whole-Body Titanium Dental Implant Surface Modifications in Inducing Adhesion, Proliferation, and Osteogenesis in Human Adipose Tissue Stem Cells

BACKGROUND

Although the influence of titanium implants' micro-surface properties on titanium discs has been extensively investigated, the research has not taken into consideration their whole-body effect, which may be considered possible using a combinatorial approach.

METHODS

Five titanium dental implants with a similar moderate roughness and different surface textures were thoroughly characterized. The cell adhesion and proliferation were assessed after adipose-tissue-derived stem cells (ADSCs) were seeded on whole-body implants. The implants' inductive properties were assessed by evaluating the osteoblastic gene expression.

RESULTS

The surface micro-topography was analyzed, showing that hydroxyapatite (HA)-blasted and bland acid etching implants had the highest roughness and a lower number of surface particles. Cell adhesion was observed after 24 h on all the implants, with the highest score registered for the HA-blasted and bland acid etching implants. Cell proliferation was observed only on the laser-treated and double-acid-etched surfaces. The ADSCs expressed collagen type I, osteonectin, and alkaline phosphatase on all the implant surfaces, with high levels on the HA-treated surfaces, which also triggered osteocalcin expression on day seven.

CONCLUSIONS

The findings of this study show that the morphology and treatment of whole titanium dental implants, primarily HA-treated and bland acid etching implants, impact the adherence and activity of ADSCs in osteogenic differentiation in the absence of specific osteo-inductive signals.

Characterization of Hydroxyapatite Film Obtained by Er:YAG Pulsed Laser Deposition on Sandblasted Titanium: An In Vitro Study

The surface of titanium (Ti) dental implants must be modified to improve their applicability, owing to the biological inertness of Ti. This study aims to use sandblasting as a pretreatment method and prepare a hydroxyapatite (HA) coating on Ti to improve its biocompatibility and induce bone bonding and osteogenesis. In this paper, sandblasted Ti discs were coated with α-tricalcium phosphate (α-TCP) via Er:YAG pulsed laser deposition (Er:YAG-PLD). An HA coating was then obtained via the hydrothermal treatment of the discs at 90 °C for 10 h. The surface characteristics of the samples were evaluated by SEM, SPM, XPS, XRD, FTIR, and tensile tests. Rat bone marrow mesenchymal stem cells were seeded on the HA-coated discs to determine cellular responses in vitro. The surface characterization results indicated the successful transformation of the HA coating with a nanorod-like morphology, and its surface roughness increased. In vitro experiments revealed increased cell attachment on the HA-coated discs, as did the cell morphology of fluorescence staining and SEM analysis; in contrast, there was no increase in cell proliferation. This study confirms that Er:YAG-PLD could be used as an implant surface-modification technique to prepare HA coatings with a nanorod-like morphology on Ti discs.

Enhancement of the biocompatibility by surface nitriding of a low-modulus titanium alloy for dental implant applications

To enhance their longevity, dental implants must be highly biocompatible and must have a low elastic modulus close to that of the bone. They must also possess a high superficial hardness and a high corrosion resistance. For these reasons, a recently developed low-modulus Ti-27Nb alloy with nontoxic elements was treated by gas nitriding at high temperature in this study. A very thin nitrided layer of 0.5 μm in thickness followed by an enriched nitrogen zone was observed. Consequently, a very high hardness evaluated at about 1800 HV was obtained in surface, which represents an increase of 4-5 times the hardness of the non-nitrided alloy. This superficial hardness was experimentally observed to decrease up to 800 nm in depth from the surface to the core. The low modulus of Ti-27Nb (evaluated at 55 GPa, which is twice lower than the commercially pure titanium) was not affected by the surface nitriding treatment. A better corrosion resistance was observed and a significant decrease in ion release rates for the nitrided alloy (ion release of 1.41 ng/cm² compared to the 163.58 ng/cm² obtained for the commercially pure titanium at pH = 7.48 in artificial Carter-Brugirard saliva). The cytocompatibility was not compromised and the cell viability performed on human osteoblasts, fibroblastic cells, and epithelial cells was enhanced on the nitrided surface in comparison with the non-nitrided surface. These combined properties make the nitrided Ti-27Nb alloy a good candidate for dental implant applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1483-1490, 2019.

Photodynamic Therapy (Association Diode Laser/Hydrogen Peroxide): Evaluation of Bactericidal Effects on Periodontopathy Bacteria: An in Vitro Study

The main cause for the development of periodontitis is the accumulation of subgingival microbial deposits organized tightly to the porous surface of the tooth cementuni. The growth of the microbial populations and the immunological reaction of the host organism are responsible for the destruction of periodontal ligament apparatus. The primary goal in the treatment of periodontitis is the complete removal of subgingival bacterial deposits. The large amount of evidence establishing a microbial etiology for periodontitis (has been the basis for the development of antimicrobial treatment approaches. Photodynamic therapy (PDT) employs a non-toxic dye, termed a photosensitizer (PS), and low intensity visible light which, in the presence of oxygen, combine to produce cytotoxic species. In this in vitro protocol study it was tested the bactericidal efficacy of Diode laser (Oralia), of Hydrogen Peroxyde and the association Diode Laser-Peroxyd Hydrogen (PDT) on Prevotella intermedia, Peptostreptococcus micros and Fusobacterium nucleatum, three of the most aggressive bacteria envolved on periodontal disease.

Modulation of osteoblast behavior on TiNxOy coatings by altering the N/O stoichiometry while maintaining a high thrombogenic potential

INTRODUCTION

Titanium nitride oxide (TiNxOy) coatings are known to stimulate osteoblast proliferation and osseointegration when compared to microrough titanium implants. The objectives of the present study were to determine whether the beneficial effects of TiNxOy coatings observed with implant osseointegration are dependent on N/O stoichiometry, with the final goal of optimizing these benefits. MMS: TiNxOy coatings with various N/O compositions were deposited on microrough titanium plates (Ti-SLA, 11 × 11 mm). Human primary osteoblast (hOBs) proliferation and gene expression were analyzed for a time course of three weeks, with or without additional stimulation by 1.25 (OH)2 vitamin D3 100 nM. Platelet adhesion/activation and thrombin generation were also assessed.

RESULTS

hOBs proliferation gradually increased with the amount of oxygen contained in the coatings. The effect was observed from day 7 to reach a maximum at day 10, with a 1.8 fold increase for the best coating as compared to Ti-SLA. SEM views indicated that cells adhered, spread and elongated faster on oxygen-rich TiNxOy films, while the differentiation process as well as the thombogenic potential was not affected.

CONCLUSIONS

The effect of TiNxOy coatings on osteoblast is dependent on their chemical composition; it increases with the amount of oxygen. TiNxOy coatings may act as a catalyst for cell-adhesion and proliferation early after seeding. In contrast, thrombogenicity of Ti-SLA surface is not affected by TiNxOy application.

Titanium-Nitride Coating of Orthopaedic Implants: A Review of the Literature. Biomed Res Int. 2015;2015:485975. [PMID: 26583113 PMCID: PMC4637053 DOI: 10.1155/2015/485975]

Surfaces of medical implants can be enhanced with the favorable properties of titanium-nitride (TiN). In a review of English medical literature, the effects of TiN-coating on orthopaedic implant material in preclinical studies were identified and the influence of these effects on the clinical outcome of TiN-coated orthopaedic implants was explored. The TiN-coating has a positive effect on the biocompatibility and tribological properties of implant surfaces; however, there are several reports of third body wear due to delamination, increased ultrahigh molecular weight polyethylene wear, and cohesive failure of the TiN-coating. This might be due to the coating process. The TiN-coating process should be optimized and standardized for titanium alloy articulating surfaces. The clinical benefit of TiN-coating of CoCrMo knee implant surfaces should be further investigated.

Osseointegration of Ti-6Al-4V alloy implants with a titanium nitride coating produced by a PIRAC nitriding technique: a long-term time course study in the rat

This study examined bone tissue responses to Ti-6Al-4V alloy implants with a hard TiN coating applied by an original powder immersion reaction-assisted coating (PIRAC) nitriding method. Progression of implant fixation in the distal epiphysis and within the medullary cavity of the rat femur was evaluated between 3 days and 6 months postimplantation by scanning electron microscopy, oxytetracycline incorporation, and histochemistry. After 6 months, successful osseointegration was achieved in both epiphyseal and diaphyseal sites. Throughout, implant portions located within the epiphysis remained in close contact with bone trabeculae that gradually engulfed the implant forming a bone collar continuous with the trabecular network of the epiphysis. In the diaphysis, woven bone was first formed within the marrow cavity around the implant and later was replaced by a shell of compact bone around the implant. In general, higher osseointegration rates were measured for TiN-coated versus the uncoated implants, both in the epiphysis and in the diaphysis. In conclusion, our findings indicate an excellent long-term biocompatibility of TiN coatings applied by the PIRAC nitriding technique and superior osteoinductive ability in comparison with uncoated Ti-6Al-4V alloy. Such coatings can, therefore, be considered for improving the corrosion and wear resistance of titanium-based orthopedic implants.

Behavior of osteoblasts on TI surface with two different coating designed for orthodontic devices

In the present study we coated Ti surfaces with polytetrafluorethylene (PTFE) and titanium nitride (TiN) and investigated in vitro the behavior of osteoblasts on these surfaces. MG-63 osteoblasts were cultured on titanium discs with different surface treatment: uncoated Ti6Al4V, TiN-coated, PTFE-coated. Cell viability/proliferation was detected by MTT assay. Gene-expression levels of alkaline phosphatase (ALP), osteocalcin (OC), type I collagen, receptor activator of nuclear factor-kappa-B ligand (RANKL), and osteoprotegerin (OPG) were determined by qPCR. Cell behavior on different surfaces was observed by time-lapse microscopy. Cells grown on PTFE-coated Ti surface exhibited delayed surface attachment and decreased proliferation after 48 h. However, after 168 h of culture cells grown on PTFE-coated surface exhibited higher viability/proliferation, higher expression levels of ALP and OC, and higher OPG/RANKL ratio compared to uncoated surface. No effect of TiN-coating on any investigated parameter was found. Our results shows that PTFE coating exhibits no toxic effect on MG-63 cells and slightly stimulates expression of several genes associated with osteogenesis. We propose that PTFE coating could be considered as a possible choice for a surface treatment of temporary skeletal anchorage devices in orthodontics.

TiNOx coatings on roughened titanium and CoCr alloy accelerate early osseointegration of dental implants in minipigs

INTRODUCTION

Titanium nitride oxide (TiNOx) coatings are known for their biocompatibility, hardness and high resistance to corrosion and wear. Further, they can be applied by plasma vapor deposition onto a wide variety of metallic, mineral, or organic substrates. In cell cultures, TiNOx coatings applied onto SLA (sandblasted, large grit, acid etched)-roughened titanium surfaces increased human primary osteoblast proliferation by 1.5 times in the first 2 weeks after seeding, while maintaining a high degree of cell differentiation. Therefore, the objectives of the present study were (i) to determine whether these findings would translate into the enhanced osseointegration of TiNOx-coated implants in vivo and (ii) to compare the osseointegration of Ti-SLA (titanium-SLA) and CoCr-SLA (cobalt-chromium-SLA) implants coated with TiNOx.

METHODS

Forty-eight cylinders made of Ti-SLA, Ti-SLA-TiNOx (TiNOx-coated Ti-SLA) and CoCr-SLA-TiNOx (TiNOx-coated CoCr-SLA) were implanted into the lower jawbone of 8 minipigs. The bone-to-implant contact was determined after 1 week, 2 weeks, 1 month and 3 months.

RESULTS

Osseointegration proceeded normally on all 3 surfaces, with equal activity after the first week of healing. After 2 weeks, bone-to-implant contact was 1.8 times higher on TiNOx coatings, either deposited on Ti or on CoCr. These differences fell off after 1 and 3 months of healing.

CONCLUSIONS

When compared to standard SLA titanium, TiNOx coatings enhance implant osseointegration during the first month of healing. Furthermore, this stimulating effect is independent of the substrate, leading to similar results whether the coating is applied onto SLA-Ti or onto SLA-CoCr.

Management Missing Later Incisor in Monozygotic Twins: Two Case Reports

Tooth loss of anterior region is the result of congenital anomaly or of a traumatic event. Maxillary lateral incisor is very important in masticatory function because permit lateral protrusion movement of mandible and is a key point in aesthetic of smile. Tooth agenesis is one of the most common developmental anomalies in man and it often is a feature of syndromes. Tooth developmental results by interactions of genetic and environmental factors, in particular mutations in MSX1, PAX9 contribute tooth agenesis, but also radiotherapy, chemotherapy, maternal systemic diseases aid genetic aberrations. Upper lateral incisor is in a unfavorable anatomical position because it's in fusion area of facial processes for this it's the most common tooth loss in oral cleft. The management of these patients is complex and it includes an orthodontic, prosthetic and surgical analysis This report addresses the fundamental considerations related to replacement of congenitally missing lateral incisors by a team approach.

Evaluation about Antimicrobical Activity of Silver in Orthoshield Safe-T-Tie® Ligatures Used in Orthodontic Patients

Purpose: to value efficacy of anti microbic propriety of silver ligatures Orthoshield Safe-T-Tie® on periodontal tissues in orthodontic patients. Materials and methods: 50 orthodontic patients between 11 and 20 years old with permanent teeth were selected in this study. We evaluated periodontal health of maxillary and mandibular lateral incisors and canines at TO before the substitution of elastomeric ligatures with Orthoshield Safe-T-Tie® ligatures and at T1 (one month after substitution of ligatures). We used PI (Periodontal Index), GI (Gingival Index) and PRC-real-time to analyze periodontal health. Results: there was an improvement of gingival inflammation and a reduction of periodontal pathogens. Conclusions: Orthoshield Safe-T-Tie® ligatures improve periodontal health in orthodontic patients.

Periodontal Lesions and Gingival Problems in Children with Acute Lymphoblastic Leukemia

Dentists both as clinical practice and research increased progressively their interest in leukemia, because the oral complications are common during the outcome of the disease, dental management is complex, and the mouth is a potential source of morbidity. The aim of this review is analyzing the most important periodontal problems due to childhood Leukaemia. Infact only with an appropriate periodontal treatment oral health could be mantained and restored before development of irreversible periodontal damage. Our experience suggests that even if detrimental impact of antineoplastic therapy on oral cavity is unavoidable, it could be diminished with an adequate and correct preventive or curative therapy contributing to a better quality of life of children treated for cancer.

The Use of Laser Diodes Superpulses in Implantology

Diode laser is a laser, usually between 810 and 980 nm wavelength, able to work on hard and soft tissues, as periodontal tissues and bone. The use of Diode laser is recommended during oral surgery or periodontal therapy, when it is necessary to erase any periodontal bacteria evolved in periodontal disease, in combination with hydrogen peroxide (photodynamic therapy), and also, by its biostimulating effects, to improve the healing of the regenerative procedures, as sinus lift, bone crestal expansion or to assist implant surgery. This article shows two cases report in which diode lasers are evolved. Diode lasers in association with Hydrogen Peroxide on utilizing the decontaminant effects oh Photodynamic Therapy, and to prepare the area defects for a regenerative surgery.

Osteogenic differentiation of dental follicle stem cells

BACKGROUND

Stem cells are defined as clonogenic cells capable of self-renewal and multi-lineage differentiation. A population of these cells has been identified in human Dental Follicle (DF). Dental Follicle Stem Cells (DFSCs) were found in pediatric unerupted wisdom teeth and have been shown to differentiate, under particular conditions, into various cell types of the mesenchymal tissues.

AIM

The aim of this study was to investigate if cells isolated from DF show stem features, differentiate toward osteoblastic phenotype and express osteoblastic markers.

METHODS

We studied the immunophenotype of DFSCs by flow cytometric analysis, the osteoblastic markers of differentiated DFSCs were assayed by histochemical methods and real-time PCR.

RESULTS

We demonstrated that DFSCs expressed a heterogeneous assortment of makers associated with stemness. Moreover DFSCs differentiated into osteoblast-like cells, producing mineralized matrix nodules and expressed the typical osteoblastic markers, Alkaline Phosphatase (ALP) and Collagen I (Coll I).

CONCLUSION

This study suggests that DFSCs may provide a cell source for tissue engineering of bone.

Titanium nitride oxide coating on rough titanium stimulates the proliferation of human primary osteoblasts

OBJECTIVES

Titanium is widely used in contemporary endosseous implantology and there is considerable thrust to further promote osseointegration by implant surface modifications. The aim of this study was to evaluate the effect of a titanium-nitride-oxide (TiNOx) coating on commercially pure microroughened titanium by assessing the proliferation and differentiation of human primary osteoblasts.

MATERIALS AND METHODS

Cell proliferation, gene expression, alkaline phosphatase activity, osteoprotegerin and osteocalcin secretion were analyzed for a time course of 3 weeks, with or without additional stimulation by 1.25(OH)(2) vitamin D(3) 100 nM.

RESULTS

A 1.5-fold increase in the proliferation rate of cells grown on TiNOx-coated titanium as compared with uncoated surfaces was observed. SEM views indicated that the cells' normal morphology with their numerous extensions was maintained. The differentiation process on the TiNOx surface was only affected to a minor degree and translated into a slight delay in osteoblast maturation when compared to uncoated titanium.

CONCLUSION

Pending confirmation of these results in vivo, TiNOx coatings could potentially accelerate and enhance osseointegration.

Vertical distraction osteogenesis using a titanium nitride-coated distractor

OBJECTIVES

The purpose of this study was to examine the effect of using a titanium nitride (TiN)-coated vertical distractor on osseointegration after implantation.

STUDY DESIGN

Four adult mongrel dogs, weighing 9-10 kg, were used in this study. The lower premolars were extracted, and vertical distraction was performed after 10 weeks using 8 distraction devices (left, 4 titanium; right, 4 nitrified). A 7-day latency period was allowed before distraction began. The distraction device was activated at a rate of 0.5 mm twice a day for 5 days. After completing distraction, the device was removed after a consolidation period of 6 weeks and 24 implants were installed. The dogs were killed after 4 or 8 weeks. Histologic examinations were performed.

RESULTS

The implant success rate was 100% in all of the study groups. Direct bone contact was achieved, and there were no significant differences between the control and experimental groups in the implantation area.

CONCLUSION

The results suggested that the nitrified distraction device does not negatively affect osseointegration in the vertical distraction osteogenesis; therefore, it has the advantageous potential to substitute for the conventional distractor.