Apical Sealing and Bioactivity of an Experimental Gutta-Percha Containing Niobium Phosphate Bioglass.

This study evaluated the apical sealing ability and bioactivity of an experimental gutta-percha containing niobium phosphate bioglass. Thirty-six human premolars were endodontically prepared and divided into three groups: GPC-filling with conventional gutta-percha; GBC-filling with bioceramic gutta-percha (EndoSequence BC); GNB-filling with experimental gutta-percha containing niobophosphate. Teeth were stored in tubes containing 2 mL of simulated body fluid (SBF) solution in an oven for 30 days.

Cholinergic control of Th17 cell pathogenicity in experimental autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE) is a mouse model of multiple sclerosis (MS) in which Th17 cells have a crucial but unclear function. Here we show that choline acetyltransferase (ChAT), which synthesizes acetylcholine (ACh), is a critical driver of pathogenicity in EAE. Mice with ChAT-deficient Th17 cells resist disease progression and show reduced brain-infiltrating immune cells.

Clinical Effect of Selective Serotonin Reuptake Inhibitors (SSRIs) on Fracture Healing.

Purpose: Chronic use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of depression has been linked to an imbalance in bone metabolism leading to osteoporosis. More recently, the use of SSRIs in murine models has been shown to delay bone healing both in vivo and in vitro by decreasing the osteoblastic differentiation and mineralization. The purpose of this study was to evaluate whether or not chronic use of SSRI's in nonunion patients increases their time to union after surgical intervention.

Inhibition of osteoclastogenesis after bisphosphonate therapy discontinuation: an in vitro approach.

Osteoclasts are specialized cells that degrade and resorb bone. Bisphosphonates (BPs) are drugs with well-known capacity to inhibit the resorption of mineralized tissues. Nitrogen-containing BPs, like alendronate (ALN) and zoledronic acid (ZA), inactivate osteoclast activity mostly by alterations on the cytoskeleton architecture of the cell.

Spontaneous Bisphosphonate-related Osteonecrosis Associated with a Tooth that Had a Necrotic Pulp: A Case Report.

This study reports the endodontic treatment performed in a patient who presented with spontaneous bone exposure in the mandible while using intravenous bisphosphonate medication (Zometa , Novartis Pharmaceuticals Co., Basel, Switzerland). A 63-year-old female patient was referred to a private dental clinic at Fortaleza, Brazil.

Author Correction: Hox gene expression determines cell fate of adult periosteal stem/progenitor cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Propranolol Reverses Impaired Fracture Healing Response Observed With Selective Serotonin Reuptake Inhibitor Treatment.

Selective serotonin reuptake inhibitors (SSRIs) are one of the most commonly prescribed antidepressants worldwide and recent data show significant impairment of fracture healing after treatment with the SSRI fluoxetine in mice. Here, we provide evidence that the negative effects of SSRIs can be overcome by administration of the beta-blocker propranolol at the time of fracture. First, in vitro experiments established that propranolol does not affect osteogenic differentiation.

Infrared Light-Emitting Diode (LED) Effects on Orthodontic Tooth Movement.

The present study aimed to analyze the effect of LED phototherapy on the presence of hyalinization and root resorption during orthodontic tooth movement (OTM) in rats and to measure the amount of tooth movement. Eighty rats were allocated into two groups: LED and control (CON), where the LED rats were irradiated with infrared LED (850 nm, 30 mW) for 5 min during the first five days of OTM and where controls were not irradiated. Both groups were subdivided into four subgroups (n=10) according to the date of euthanasia (4, 7, 14 and 21 days).

KLF4 as a rheostat of osteolysis and osteogenesis in prostate tumors in the bone.

We previously showed that KLF4, a gene highly expressed in murine prostate stem cells, blocks the progression of indolent intraepithelial prostatic lesions into aggressive and rapidly growing tumors. Here, we show that the anti-tumorigenic effect of KLF4 extends to PC3 human prostate cancer cells growing in the bone. We compared KLF4 null cells with cells transduced with a DOX-inducible KLF4 expression system, and find KLF4 function inhibits PC3 growth in monolayer and soft agar cultures.

Hox gene expression determines cell fate of adult periosteal stem/progenitor cells.

Hox genes are evolutionarily conserved transcription factors that during embryonic development function as master regulators of positional identity. In postnatal life, the function of Hox proteins is less clear: Hox genes are expressed during tissue repair, but in this context their function(s) are largely unknown. Here we show that Hox genes are expressed in periosteal stem/progenitor cells in a distribution similar to that during embryonic development.

Age-related inflammation triggers skeletal stem/progenitor cell dysfunction.

Aging is associated with impaired tissue regeneration. Stem cell number and function have been identified as potential culprits. We first demonstrate a direct correlation between stem cell number and time to bone fracture union in a human patient cohort.

Ecto-5'-nucleotidase (CD73) regulates bone formation and remodeling during intramembranous bone repair in aging mice.

Ecto-5'-nucleotidase (CD73) generates adenosine, an osteoblast activator and key regulator of skeletal growth. It is unknown, however, if CD73 regulates osteogenic differentiation during fracture healing in adulthood, and in particular how CD73 activity regulates intramembranous bone repair in the elderly. Monocortical tibial defects were created in 46-52-week-old wild type (WT) and CD73 knock-out mice (CD73) mice.

Effects of bisphosphonates on osteogenesis and osteoclastogenesis signaling during the endochondral ossification of growing rats.

Osteoclasts and chondroclasts are necessary, during endochondral ossification, for the resorption of primary bone and calcified cartilage septa, respectively. The bisphosphonates inhibit mineralized tissue resorption by various mechanisms according to the different types of this drug, which can affect bone remodeling during skeletal growth. The objective of the present study is to analyze the way that alendronate (ALN) and etidronate (ETN) can affect osteoclastogenesis and bone formation during endochondral ossification of the long bones of growing rats.

Strontium Ranelate Effect on the Repair of Bone Defects and Molecular Components of the Cortical Bone of Rats.

This study was conducted to evaluate the effects of treatment with strontium ranelate (SR) on the repair of bone defects and molecular components of bones in femurs. Adult female rats (n=27) were subjected to ovariectomy (OVX) or Sham surgery. Thirty days after surgery, a defect was made in the femur and the animals were then divided into three groups: OVX, SHAM and OVX+SR.

The Selective Serotonin Reuptake Inhibitor Fluoxetine Directly Inhibits Osteoblast Differentiation and Mineralization During Fracture Healing in Mice.

Chronic use of selective serotonin reuptake inhibitors (SSRIs) for the treatment of depression has been linked to osteoporosis. In this study, we investigated the effect of chronic SSRI use on fracture healing in two murine models of bone regeneration. First, we performed a comprehensive analysis of endochondral bone healing in a femur fracture model.

Evaluation of bone repair of critical size defects treated with simvastatin-loaded poly(lactic-co-glycolic acid) microspheres in rat calvaria.

Purpose: Statins are hypolipemiant drugs with osteoinductive effect. We evaluated the potential of simvastatin loaded into poly(lactic-co-glycolic acid) (PLGA) microspheres to heal critical size defects in rat calvaria.

Methods: PLGA scaffolds (50:50 ratio) were synthesized as pure membranes or as microspheres loaded with 2.

Ultrastructural and biochemical analysis of the effects of alendronate on salivary glands of young rats.

Introduction: The bisphosphonates are drugs known by their antiresorptive potency and are widely prescribed for treating and preventing osteoporosis. In the past years the employment of this class of drugs had spread to other pathologies, and it is being prescribed to patients in a wide range of ages. Some adverse effects of bisphosphonate treatment have been highlighted recently, however, little is known about its potential side effects in salivary glands.

Ultrastructural and immunohistochemical study of the effect of sodium alendronate in the progression of experimental periodontitis in rats.

The aim of the present research was to investigate the ultrastructural aspects and the immunoexpression of receptor activator of NFκB ligand (RANKL) and osteoprotegerin (OPG) on experimental periodontal disease of alendronate (ALN)-treated rats. Male Wistar rats received daily injections of 2.5 mg/kg body weight of ALN during 7 days previously and 7, 14, and 21 days after the insertion of a 4.

Effects of the bisphosphonate alendronate on molars of young rats after lateral luxation.

Background And Aim: The bisphosphonate alendronate (ALN) was employed with the aim of investigating its effects on dental and periodontal tissues after lateral luxation of developing molars.

Material And Methods: Twenty-one-day-old Wistar rats had their second upper molars laterally luxated. Daily 2.

Immunolocalization of Smad-4 in developing molar roots of alendronate-treated rats.

Introduction: During root formation, Smad-4 plays a key role during the epithelial-mesenchymal interactions and the Hertwig's epithelial root sheath (HERS) apical proliferation. The root formation and eruption of rat molars is impeded by alendronate treatment due to the inhibition of bone resortion by this drug. The present study aimed to examine the structures affected in the developing root and immunodetect the presence of Smad-4 in rats treated with alendronate.

Reduced RANKL expression impedes osteoclast activation and tooth eruption in alendronate-treated rats.

The creation of the eruption pathway requires the resorption of the occlusal alveolar bone by osteoclasts and signaling events between bone and dental follicle are necessary. The aim of the present study has been to evaluate the effect of alendronate on osteoclastogenesis and the expression of the regulator proteins of osteoclast activation, namely RANK, RANKL and OPG, in the bone that covers the first molar germ. Newborn Wistar rats were treated daily with 2.

Ultrastructural and immunohistochemical study of early repair of alveolar sockets after the extraction of molars from alendronate-treated rats.

The aim of the present research was to analyze ultrastructural and immunohistochemical aspects of the alveolar repair after the extraction of molars of alendronate (ALN)-treated rats. Wistar rats received 2.5mg/kg body wt/day of ALN during 14 days previously and 7, 14 and 21 days after the extraction of the second mandibular molar.

Enoxacin directly inhibits osteoclastogenesis without inducing apoptosis.

Enoxacin has been identified as a small molecule inhibitor of binding between the B2-subunit of vacuolar H+-ATPase (V-ATPase) and microfilaments. It inhibits bone resorption by calcitriol-stimulated mouse marrow cultures. We hypothesized that enoxacin acts directly and specifically on osteoclasts by disrupting the interaction between plasma membrane-directed V-ATPases, which contain the osteoclast-selective a3-subunit of V-ATPase, and microfilaments.

Early alveolar bone regeneration in rats after topical administration of simvastatin.

Objectives: The aim of this study was to ultrastructurally examine the influence of simvastatin on bone healing in surgically created defects in rat mandibles.

Study Design: Bone defects 0.8 mm in diameter were created in the buccal aspect of first mandibular molar roots and filled with 2.

Clastic cells: mineralized tissue resorption in health and disease.

Clastic cells are responsible for mineralized tissue resorption. Bone resorbing cells are called osteoclasts; however, they are able to resorb mineralized dental tissues or calcified cartilage and then they are called odontoclasts and chondroclasts, respectively. They derive from mononuclear precursors of the monocyte-macrophage lineage from hemopoietic tissue, reach target mineralized tissues and degrade them under many different physiologic or pathologic stimuli.