Strontium-loaded hydrogel scaffolds to promote gingival fibroblast function.

Dental implant clinical success is dependent on effective peri-implant tissue attachment to the trans-mucosal portion following placement. Modification of transmucosal implant surfaces can improve cellular adhesion and function leading to formation of an effective soft-tissue seal during healing, of which gingival fibroblasts are prominent cells to migrate to repair wounds and crucial for the development of a collagen rich connective tissue. Biocompatible loaded scaffold materials have been developed to allow local release of molecules with effective biological activity.

Efficacy of CPP-ACP fluoride varnish applied with and without acid etching in preventing enamel demineralization compared to light-curable fluoride varnish.

Objectives: To compare efficacy of casein phosphopeptide (CPP)-amorphous calcium phosphate (ACP) fluoride varnish and light-curable resin modified glass ionomer fluoride varnish (FV) in preventing white spot lesions and evaluating acid etching prior to CPP-ACPFV application on its efficacy.

Materials And Methods: Molars and premolars were transected and halves divided into four groups (n = 18/group): (1) resin-modified glass ionomer FV: etched and Clinpro-XT varnish (3M ESPE, Pymble, New South Wales, Australia) application; (2) CPP-ACPFV: MI varnish (GC America, Alsip, IL) application; (3) Etch+CPP-ACPFV: etched and MI varnish application; (4) Control: etched and no surface treatment. To simulate 12 weeks in an intraoral environment, samples were subjected to thermocycling, brushing, and pH cycling.

Bisphosphonate-related osteonecrosis of the jaw: Current clinical significance and treatment strategy review.

Purpose: This review paper is intended to provide updated information about the significance of bisphosphonate-related osteonecrosis of the jaw (BRONJ) related to dental departments and also to provide treatment information. However, it does not review anti-resorptive related osteonecrosis of the jaw (ARONJ).

Methods: PubMED was searched for published articles on BRONJ that have particular relevance to clinical aspects in orthodontics, endodontics, periodontics, prosthodontics, oral and maxillofacial surgery, implants and treatment planning.

Strontium Effects on Human Gingival Fibroblasts.

Strontium is a naturally occurring alkaline earth metal that has been shown to be useful not only in the treatment and prevention of osteoporosis but also in the treatment of dentinal hypersensitivity in the oral cavity; strontium is also an effective cariostatic, antiplaque, antigingivitis agent. Relatively little is known, however, about the effects of strontium on gingival fibroblasts. The purpose of the present investigation was to conduct in vitro studies on the potential for strontium to positively affect the activity of these cells such that it might be effective in the enhancement of gingival attachment to surfaces, such as healing abutments in implants in the oral cavity.

Biocompatibility and bond degradation of poly-acrylic acid coated copper iodide-adhesives.

Objective: To investigate the effect of poly-acrylic acid (PAA) copper iodide (CuI) adhesives on bond degradation, tensile strength, and biocompatibility.

Methods: PAA-CuI particles were incorporated into Optibond XTR, Optibond Solo and XP Bond in 0.1 and 0.

The combination of nano-calcium sulfate/platelet rich plasma gel scaffold with BMP2 gene-modified mesenchymal stem cells promotes bone regeneration in rat critical-sized calvarial defects.

Background: Mesenchymal stem cells (MSCs) can be differentiated into an osteoblastic lineage in the presence of growth factors (GFs). Platelet-rich plasma (PRP), which can be easily isolated from whole blood, contains a large amount of GFs, and, therefore, promotes bone growth and regeneration. The main goal of this work was to develop and investigate the effect of a new sandwich-like bone scaffold which combines a nano-calcium sulfate (nCS) disc along with PRP fibrin gel (nCS/PRP) with BMP2-modified MSCs on bone repair and regeneration in rat critical-sized calvarial defects.

Promotion of cells to close gaps and encourage cell coverage, by radio frequency glow discharge treatment.

Exposure of dental abutments to cleaning and sterilizing Radio Frequency Glow Discharge Treatment (RFGDT) triggered greater degrees of human gingival fibroblast (HGF) attachment and spreading over their surfaces. Enhanced cell growth and metabolic activity of such HGFs were found which might lead to improved cellular margins in the smile-revealing "esthetic zone". This investigation, approved by the Institutional Review Board, employed in vitro studies of HGFs to support in vivo clinical applications of differentially treated titanium healing abutments to demonstrate the possible improvements for tissue growth around dental implants.

Hybrid Biomaterial with Conjugated Growth Factors and Mesenchymal Stem Cells for Ectopic Bone Formation.

Bone is a highly vascularized tissue and efficient bone regeneration requires neovascularization, especially for critical-sized bone defects. We developed a novel hybrid biomaterial comprising nanocalcium sulfate (nCS) and fibrin hydrogel to deliver mesenchymal stem cells (MSCs) and angiogenic factors, vascular endothelial growth factor (VEGF) and fibroblast growth factor 9 (FGF9), to promote neovascularization and bone formation. MSC and growth factor(s)-loaded scaffolds were implanted subcutaneously into mice to examine their angiogenic and osteogenic potential.

Combination of Controlled Release Platelet-Rich Plasma Alginate Beads and Bone Morphogenetic Protein-2 Genetically Modified Mesenchymal Stem Cells for Bone Regeneration.

Background: Platelet-rich plasma (PRP) consists of platelet-derived growth factor and transforming growth factor-β that increase proliferation of mesenchymal stem cells (MSCs), whereas bone morphogenetic protein-2 (BMP2) promotes osteogenic differentiation of MSCs. However, the high degradation rate of fibrin leads to the dissociation of cytokines even before the process of bone regeneration begins. To the best of the authors' knowledge, this is the first study to examine the combined effect of sustained release of PRP from alginate beads on BMP2-modified MSC osteogenic differentiation in vitro and sustained release of PRP alone on a fracture defect model ex vivo as well as its effect on calvarial suture closure.

The role of sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) in regulation of osteoclastic and osteoblastic cells.

The bioactive lipid molecules, sphingosine-1-phosphate (S1P) and lysophosphatidic acid LPA) have recently emerged as potentially highly significant physiological and pathophysiological regulators of bone cell biology. Since compromised signaling by these bioactive lipids has been implicated in the etiology of disorders such as inflammatory and autoimmune diseases, their role in bone biology can be a key influence in the coordination of the events underlying osteoimmunology. Both S1P and LPA have been shown to have receptor-mediated effects on osteoblastic cell proliferation and differentiation critical to bone formation and on osteoclastic cell action and regulation of bone resorption.

BMP2 genetically engineered MSCs and EPCs promote vascularized bone regeneration in rat critical-sized calvarial bone defects.

Current clinical therapies for critical-sized bone defects (CSBDs) remain far from ideal. Previous studies have demonstrated that engineering bone tissue using mesenchymal stem cells (MSCs) is feasible. However, this approach is not effective for CSBDs due to inadequate vascularization.

Integration of a novel injectable nano calcium sulfate/alginate scaffold and BMP2 gene-modified mesenchymal stem cells for bone regeneration.

The repair of craniofacial bone defects is surgically challenging due to the complex anatomical structure of the craniofacial skeleton. Current strategies for bone tissue engineering using a preformed scaffold have not resulted in the expected clinical regeneration due to difficulty in seeding cells into the deep internal space of scaffold, and the inability to inject them in minimally invasive surgeries. In this study, we used the osteoconductive and mechanical properties of nano-scale calcium sulfate (nCS) and the biocompatibility of alginate to develop the injectable nCS/alginate (nCS/A) paste, and characterized the effect of this nCS/A paste loaded with bone morphogenetic protein 2 (BMP2) gene-modified rat mesenchymal stem cells (MSCs) on bone and blood vessel growth.

Human periodontal ligament cells reaction on a novel hydroxyapatite-collagen scaffold.

Background: Periodontal tissue regeneration presents a highly promising method for restoring periodontal structures. The development of a suitable bioactive scaffold that promotes cell proliferation and differentiation is critical in periodontal tissue engineering. The aim of this study was to evaluate the biocompatibility of a novel 3-dimensional hydroxyapatite-collagen scaffold with human periodontal ligament (hPDL) cell culture.

Synthesis and characterization of nanocrystalline calcium sulfate for use in osseous regeneration.

Nanoparticles of calcium sulfate (nCS) have potential advantages as a ceramic matrix, scaffold and/or vehicle for delivering growth factors for osseous regeneration in a variety of clinical situations. The objectives of this study were to synthesize and characterize nanoparticles of hemihydrate calcium sulfate (nCS) and to develop a nCS-based system for bone regeneration. A cryo-vacuum method was used to process dihydrate CS into dihydrate nCS, which was then subjected to oven drying to produce hemihydrate.

The effect of doxycycline hyclate, chlorhexidine gluconate, and minocycline hydrochloride on osteoblastic proliferation and differentiation in vitro.

Background: The purpose of this study was to determine the effect of the active substance of three types of local delivery systems, doxycycline hyclate 10% (DOXY), chlorhexidine gluconate, 2.5 mg (CHX), and minocycline hydrochloride, 1 mg (MINO), on osteoblastic cell proliferation and differentiation.

Methods: There were four groups: control osteoblastic cells (OB) alone, OB + DOXY, OB + CHX, and OB + MINO.

Effects of platelet-derived growth factor, vitamin D and parathyroid hormone on osteoblasts derived from cancer patients on chronic bisphosphonate therapy.

Bisphosphonates consist of a family of pyrophosphate analogues that are currently being used to treat metastatic bone diseases as well as systemic bone diseases such as osteoporosis. There is accumulating evidence suggesting that patients treated with these bisphosphonates can develop, particularly with invasive dental procedures, osteonecrosis of the jaw. This present study investigated the ability of osteoblastic cells obtained from the alveolar bone of patients on long term intravenous bisphosphonate therapy to respond to agents normally involved in bone regulation and repair.

Nicotine induced proliferation and cytokine release in osteoblastic cells.

Smoking has deleterious effects on osteoporosis and periodontitis both characterized by bone loss. Smoking also interferes with the protective effect that hormone replacement therapy (HRT) has on bone loss. Our study investigated two mechanisms by which smoking may affect bone metabolism: nicotine-induced proliferation and nicotine-induced cytokine secretion in osteoblasts.

Platelet-derived growth factor enhancement of two alloplastic bone matrices.

Background: The use of alloplastic matrices that mimic the mineral phase of bone has become a viable alternative to current mainstream therapies in dentistry such as allografts and autogenous grafts. Because alloplastic bone substitutes generally have relatively poor osteogenic properties, analyzing their potential as vehicles to deliver growth factors is an important step in assessing methods to enhance their clinical efficacy. The aim of these studies was to treat beta-tricalcium phosphate (beta-TCP) and calcium sulfate (CaSO(4)) with platelet-derived growth factor (PDGF)-BB to enhance the osteogenic capabilities of these materials.

Alveolar bone osteoblast differentiation and Runx2/Cbfa1 expression.

Alveolar bone cells have a unique origin and functionality, but may resemble skeletal osteoblasts. Osteoblast differentiation and gene expression are regulated by the Runx2/Cbfa1 transcription factor. However, most studies on Runx2/Cbfa1 expression have been on rodent cells and the few studies on human osteoblasts have had differing results.

Engineering a bioactive matrix by modifications of calcium sulfate.

The goal of this study was to define the conditions for the fabrication of a bioactive matrix that induces and supports cell proliferation and tissue regeneration. The proposed hypothesis was that a composite graft could be engineered by the absorption of platelet-rich plasma (PRP) onto calcium sulfate (CS). Evaluation of the biological activity of the engineered grafts was based on osteoblast proliferation studies and scanning electron microscopy (SEM) analyses.