Optimization of three-dimensional printing parameters for orthodontic applications.

Objectives: To determine the impact of build orientation, increased layer thickness, and dental crowding on the trueness of three-dimensional (3D)-printed models, and to evaluate how these parameters affect the fit of thermoformed appliances.

Materials And Methods: Ninety-six dental models were printed horizontally and vertically on the building platform using different 3D-printing technologies: (1) a stereolithography (SLA) printer with layer thicknesses of 160 μm and 300 μm and (2) a digital light processing (DLP) printer with layer thicknesses of 100 μm and 200 μm. Each printed model was digitalized and superimposed on the corresponding source file using 3D rendering software, and deviations were quantified by the root mean square values.

Receptor activator of nuclear factor-kappa B is enriched in CD9-positive extracellular vesicles released by osteoclasts.

Aim: Receptor activator of nuclear factor-kappa B (RANK)-containing extracellular vesicles (EVs) bind RANK-Ligand (RANKL) on osteoblasts, and thereby simultaneously inhibit bone resorption and promote bone formation. Because of this, they are attractive candidates for therapeutic bone anabolic agents. Previously, RANK was detected in 1 in every 36 EVs from osteoclasts by immunogold electron microscopy.

Metabolomic signatures distinguish extracellular vesicles from osteoclasts and odontoclasts.

Aims: Pathological dental root resorption and alveolar bone loss are often detected only after irreversible damage. Biomarkers in the gingival crevicular fluid or saliva could provide a means for early detection; however, such biomarkers have proven elusive. We hypothesize that a multiomic approach might yield reliable diagnostic signatures for root resorption and alveolar bone loss.

The effects of corticotomy and piezocision in orthodontic canine retraction: a randomized controlled clinical trial.

Background: The aims of this study were to evaluate the efficacy of alveolar corticotomy (AC) and piezocision (PZ) in accelerating maxillary canine retraction, and their effects on multiple bone remodeling expression in gingival crevicular fluid (GCF). A split-mouth, randomized controlled clinical trial was performed at the Department of Orthodontics of Pontifical Catholic University of Minas Gerais, Brazil. Eligibility criteria included orthodontic need for first maxillary premolars extractions, followed by canine retraction.

RANKL and RANK in extracellular vesicles: surprising new players in bone remodeling.

Receptor activator of nuclear factor kappa B-ligand (RANKL), its receptor RANK, and osteoprotegerin which binds RANKL and acts as a soluble decoy receptor, are essential controllers of bone remodeling. They also play important roles in establishing immune tolerance and in the development of the lymphatic system and mammary glands. In bone, RANKL stimulates osteoclast formation by binding RANK on osteoclast precursors and osteoclasts.

Actin and Actin-Associated Proteins in Extracellular Vesicles Shed by Osteoclasts.

Extracellular vesicles (EVs) are shed by all eukaryotic cells and have emerged as important intercellular regulators. EVs released by osteoclasts were recently identified as important coupling factors in bone remodeling. They are shed as osteoclasts resorb bone and stimulate osteoblasts to form bone to replace the bone resorbed.

The proteome of extracellular vesicles released by clastic cells differs based on their substrate.

Extracellular vesicles (EVs) from osteoclasts are important regulators in intercellular communication. Here, we investigated the proteome of EVs from clastic cells plated on plastic (clasts), bone (osteoclasts) and dentin (odontoclasts) by two-dimensional high performance liquid chromatography mass spectrometry seeking differences attributable to distinct mineralized matrices. A total of 1,952 proteins were identified.

Extracellular vesicle identification in tooth movement models.

Extracellular vesicles (EVs) are 30-150 nm in diameter vesicles released by cells that serve important intercellular regulatory functions. EVs include exosomes and microvesicles. Exosomes form in multivesicular bodies and are released extracellularly as the multivesicular bodies fuse with the plasma membrane.

Clastic cells in orthodontic treatment: Translational challenges and recent advances.

Objectives: Orthodontic treatment consists of numerous appliance activations that rely on stimulation of osteoclasts at alveolar bone sites. However, the action of osteoclast-like cells on dentin ("odontoclasts") is a pathological side effect of orthodontic treatment. The aim of this article is twofold: (a) To report preliminary results from ongoing cell culture experiments to identify unique markers of dentin resorption, and (b) To discuss our work using nanoparticle tracking analysis (NTA) and exosomes for developing biological fluid-based biopsies to monitor clastic cell activity.

Enoxacin and bis-enoxacin stimulate 4T1 murine breast cancer cells to release extracellular vesicles that inhibit osteoclastogenesis.

Enoxacin and its bone-seeking bisphosphonate derivative, bis-enoxacin, have recently captured attention as potential therapeutic agents for the treatment of cancer and bone disease. No differences in growth or survival of 4T1 murine breast cancer cells were detected at a concentration of 50 µM of enoxacin or bis-enoxacin. Growth was perturbed at higher concentrations.

Clinical Characteristics of Localized Aggressive Periodontitis in Primary Dentition.

Objectives: Due to the low prevalence of localized aggressive periodontitis (LAP), clinical characteristics of LAP in primary dentition are derived from a few case reports/series in the literature. The goal of this study was to determine common clinical characteristics such as bone and root resorption patterns, in a series of cases with LAP in primary dentition. We hypothesize these cases present aggressive periodontal bone destruction starting mostly around first primary molars and atypical root resorption patterns.

A prospective randomized clinical trial into the capacity of a toothpaste containing NovaMin to prevent white spot lesions and gingivitis during orthodontic treatment.

Background: White spot lesions and gingivitis represent common, yet challenging, dilemmas for orthodontists. Fluoride has shown some benefit as a protective measure against demineralization; however, this is usually insufficient for orthodontic patients with less than ideal oral hygiene. Dentifrices containing calcium sodium phosphosilicate bioactive glass (NovaMin) have been proposed to aid in prevention of white spot lesions and gingival inflammation.

Immunoassay analysis of proteins in gingival crevicular fluid samples from resorbing teeth.

Objective: To carry out an immunoassay analysis of biomarkers expressed in gingival crevicular fluid (GCF) with the main goal of finding a useful diagnostic pattern to distinguish between resorbing deciduous teeth and nonresorbing controls.

Materials And Methods: A split-mouth design was used in this study with a total of 22 GCF samples collected from 11 patients in the mixed dentition. For each child, one deciduous molar with radiographic evidence of root resorption was used as the test tooth whereas the contralateral first permanent molar with formed roots was used as the control tooth.

Mass spectrometry analysis of gingival crevicular fluid in the presence of external root resorption.

Introduction: In this study, we used liquid chromatography-mass spectrometry (LC-MS) to investigate the differences in the composition of gingival crevicular fluid between resorbing deciduous molars and nonresorbing permanent teeth. The main goal was to identify novel biomarkers associated with root resorption.

Methods: Eleven children (4 boys, 7 girls) in the mixed dentition were selected to participate in this split-mouth design study, in which a deciduous second molar with radiographic evidence of root resorption served as the experimental site, and the permanent first molar on the contralateral quadrant was the control site.

Differences in the gingival crevicular fluid composition between adults and adolescents undergoing orthodontic treatment.

Objectives: To investigate differences in the gingival crevicular fluid (GCF) composition between adolescent and adult patients undergoing orthodontic treatment with fixed appliances.

Materials And Methods: Ten adolescents (14.4 ± 1.

Digital analysis of staining properties of clear aesthetic brackets.

Objective: To analyse the staining properties of clear orthodontic brackets using a digital analysis.

Design: In vitro, laboratory study

Material And Methods: A total of 500 tooth-coloured brackets from 10 brands (five ceramic and five plastic) were investigated. The cumulative discolouring effect of staining agents (tea, coffee, curry and red wine) were analysed at two consumption levels: light and heavy, based on a 6-month period of exposure.

Relapse of orthodontically corrected deepbites in accordance with growth pattern.

Introduction: A common orthodontic problem is a deep overbite malocclusion. Because of its high relapse tendency, it is also one of the most challenging problems to treat. To minimize relapse, the morphologic characteristics of patients need to be considered.

Effect of tooth bleaching on shear bond strength of a fluoride-releasing sealant.

Objective: To evaluate the effect of an in-office plus at-home bleaching protocol on shear bond strength of orthodontic buttons when using a fluoride-releasing sealant.

Materials And Methods: Extracted human molars (160) were randomly divided into bleached (n  =  80) and unbleached groups (n  =  80). The bleached group was treated with 45% carbamide peroxide for 30 minutes, followed by five applications of 20% carbamide peroxide at 24-hour intervals.

Impact of orthodontic retainers on periodontal health status assessed by biomarkers in gingival crevicular fluid.

Objective: To evaluate whether biomarkers of inflammation and periodontal remodeling are differentially expressed in the gingival crevicular fluid (GCF) of patients wearing different types of orthodontic retainers.

Materials And Methods: Thirty-one adult subjects (17 men and 14 women with an age range of 20 to 35 years) were allocated to three different groups. Group 1 consisted of 10 patients wearing fixed retainers, group 2 included 11 patients using lower removable retainers, and group 3 comprised 10 patients without retainers (control).

Esthetics and smile characteristics evaluated by laypersons.

Objective: To collect data regarding Canadian laypersons' perceptions of smile esthetics and compare these data to US data in order to evaluate cultural differences.

Materials And Methods: Using Adobe Photoshop 7, a digital image of a posed smile of a sexually ambiguous lower face was prepared so that hard and soft tissue could be manipulated to alter buccal corridor (BC), gingival display (GD), occlusal cant (OC), maxillary midline to face discrepancy (MMFD), and lateral central gingival discrepancy (LCGD). Adult Canadian laypersons (n  =  103) completed an interactive computer-based survey of 29 randomized images to compare smile preferences for these variables.