Characterisation of Drug Delivery Efficacy Using Microstructure-Assisted Application of a Range of APIs.

Polymer-based solid microstructures (MSts) have the potential to significantly increase the quantity and range of drugs that can be administered across the skin. MSt arrays are used to demonstrate their capacity to bypass the skin barrier and enhance permeability by creating microchannels through the , in a minimally invasive manner. This study is designed to demonstrate the ability of MSts to exceed the current boundaries for transdermal delivery of compounds with different molecular weights, partition coefficients, acid dissociation constants, melting points, and water solubilities.

Fracture resistance of endodontically treated teeth without ferrule using a novel H-shaped short post.

Objective: To evaluate the fracture resistance and failure types of modified H-designed intradental short retention preparation for computer-aided design/computer-assisted manufacture (CAD/CAM) restorations, in cases where no ferrule is possible.

Method And Materials: A combined finite element analysis and in vitro testing was employed. Forty extracted single-rooted premolars were selected and prepared for the following four groups (n = 10 per group): Group A, H-post preparation restored with glass-ceramic crowns; group B, H-post preparation restored with lithium disilicate crowns; group C, endocrowns (negative control group); and group D, 2-mm ferrule preparation and restoration with fiber posts (positive control).

FEA evaluation of the resistance form of a premolar crown.

Purpose: The purpose of this study was to evaluate the influence of buccal and lingual wall convergence angles on the ability of the preparation to resist rotational displacement.

Materials And Methods: An intact premolar digitized by micro-CT yielded a 3D reproduction of a human tooth. Simulated crown preparations with known buccolingual axial wall convergence angles (4°, 8°, 12°, 16°, 20°, 24°, 28° 32°), sloped-shoulder marginal area, and occlusal reduction were created and restored with a ceramic crown.

Induction of osteopenia during experimental tooth movement in the rat: alveolar bone remodelling and the mechanostat theory.

Increases in bone strains above a certain threshold have a positive effect on bone mass, whereas reductions in strain magnitude lead to bone loss and osteopenia; the term 'mechanostat' has been introduced to describe this tissue-level negative feedback mechanism. The mechanobiology of bone and particularly alveolar bone is poorly understood, and whether the mechanostat theory has any relevance to explaining the osseous changes that occur during orthodontic tooth movement remains unclear. To investigate the relationship further, an expansile force of 0.

Mechanical responses to orthodontic loading: a 3-dimensional finite element multi-tooth model.

Introduction: The initial mechanical response to orthodontic loading comprises biologic reactions that remain unclear, despite their clinical significance. We used a 3-dimensional finite element analysis to investigate the stress-strain responses of teeth to orthodontic loading.

Methods: The model was derived from computed tomography data, with adequate boundary conditions and tissue characterization, with orthodontic hardware to provide a more accurate reflection of events during orthodontic therapy.