Multishot Diffusion-Weighted MRI of the Breast With Multiplexed Sensitivity Encoding (MUSE) and Shot Locally Low-Rank (Shot-LLR) Reconstructions.

Background: Diffusion-weighted imaging (DWI) has shown promise to screen for breast cancer without a contrast injection, but image distortion and low spatial resolution limit standard single-shot DWI. Multishot DWI methods address these limitations but introduce shot-to-shot phase variations requiring correction during reconstruction.

Purpose: To investigate the performance of two multishot DWI reconstruction methods, multiplexed sensitivity encoding (MUSE) and shot locally low-rank (shot-LLR), compared to single-shot DWI in the breast.

A new frog species from rapidly dwindling cloud forest streams of Sri Lanka-Lankanectes pera (Anura, Nyctibatrachidae).

The monotypic genus Lankanectes, considered an evolutionary long branch with India's Nyctibatrachus as its sister lineage, is represented by L. corrugatus, a species widely distributed within the wet zone of Sri Lanka up to 1500 m asl, where it inhabits a variety of lotic and lentic habitats. Here, following an integrative taxonomic approach using DNA-based phylogenies, morphology, morphometry, and ecological niche models, we describe a new species-Lankanectes pera sp.

Nerve ultrasound in electrophysiologically verified tarsal tunnel syndrome.

Introduction: Tarsal tunnel syndrome (TTS) arises from tibial nerve damage under the flexor retinaculum of the fibro-osseus tunnel at the medial malleolus. It is notoriously difficult to diagnose, as many other foot pathologies result in a similar clinical picture. We examined the additional value of nerve ultrasound in patients with tarsal tunnel syndrome confirmed by nerve conduction.

Taper of full-veneer crown preparations by dental students at the University of the West Indies.

Purpose: The ideal taper recommended for a full-veneer crown is 4° to 14°, but this is very difficult to achieve clinically, and studies on taper achieved by dental students have found mean taper measurements ranging from 11° to 27°. The objective of this study was to examine and compare the taper of teeth prepared for full-veneer crowns by dental students on typodonts in the laboratory and on patients, and also to compare the results with those of other dental schools.

Materials And Methods: Preparations were scanned by specialized metrology equipment that gave the taper of the preparation in a buccolingual (BL) and mesiodistal (MD) plane.

Opposing effects of glucocorticoids and Wnt signaling on Krox20 and mineral deposition in osteoblast cultures.

Krox20 is expressed in osteoblasts and chondrocytes, and is required for trabecular bone formation during embryogenesis. Here we show by RT-qPCR and Western blot analysis that Krox20 is up-regulated during late stages of osteoblast differentiation in culture. Glucocorticoids (GCs) rapidly inhibit the expression of Krox20 as well its co-activator, HCF-1, resulting in inhibition of the Osteocalcin Krox20-binding Enhancer (OKE).

Consistency of labial finish line preparation for metal ceramic crowns: an investigation of a new bur.

Purpose: Previous studies have reported on the difficulties inherent in preparing the labial aspect of teeth for metal ceramic crowns with consistency and also the implications for the definitive restoration of underprepared and overangled finish lines. In this study, a bur designed to prepare a 1.2-mm deep chamfer was tested and compared with two other bur kits.

Abutment taper of full cast crown preparations by dental students in the UWI School of Dentistry.

Retention of crowns has been shown to be inversely proportional to taper. The objective of this study was to compare the abutment taper of teeth prepared for full veneer crowns by students at the UWI School of Dentistry with those of other dental schools. Twenty five dies were scanned by a Co-ordinate Measuring Machine (CMM) and the mean taper and standard deviations were found to be 20.

The nucleation and crystallization of fine grained leucite glass-ceramics for dental applications.

Objectives: The aims of the study were to control the nucleation and crystal growth of selected aluminosilicate glass powders, to produce uniform leucite glass-ceramic microstructures consisting of fine (<1000 nm) grained leucite crystals.

Methods: A starting glass composition of wt%; 64.2% SiO(2), 16.

Dentin exposure in tooth preparations for porcelain veneers: a pilot study.

Statement Of Problem: The various clinical techniques available for even reduction of a tooth surface to receive a porcelain veneer restoration do not produce a consistently even conservative reduction. In addition, it is not known which technique is most conservative of enamel.

Purpose: The purpose of this pilot study was to assess the effectiveness of 3 clinical techniques, namely, dimple, depth groove, and freehand, in producing an intraenamel preparation.

A comparison of dimensional accuracy between three different addition cured silicone impression materials.

Ten impressions of a metal implant abutment were made with each of three addition-cured silicone impression materials. Using the technique of co-ordinate metrology, the shoulder region of the abutment and corresponding regions of both impressions and dies made from these impressions were scanned and measured. Comparison of these measurements indicated that the mean dimension measured from the shoulder region for each group of impression materials was significantly different from those taken from the original metal implant abutment.

Geographic distribution of porcelain veneer preparation depth with various clinical techniques.

Statement Of Problem: Various clinical techniques have been advocated for uniform reduction of the tooth surface before a porcelain veneer restoration. Often these techniques do not produce a consistently uniform labial reduction.

Purpose: The purpose of this study was to identify the degree of inconsistency on a geographic scale in the depth of labial reduction for porcelain veneers, resulting from the use of 3 clinical techniques.

The effect of veneering and heat treatment on the flexural strength of Empress 2 ceramics.

Objectives: The aims of the study were to test and compare the biaxial flexural strength and reliability of Empress 2 ceramics after heat treatment and the addition of the veneering material and to characterise their microstructures.

Methods: Forty disc specimens (2 x 14 mm) and forty disc specimens (1 x 14 mm) were produced by heat pressing in the EP 500 press furnace. Group 1 (2 x 14 mm Empress 2 core) was as heat pressed and group 2 (2 x 14 mm Empress 2 core) was subjected to the recommended firing cycles.

A study into the variations in the labial reduction of teeth prepared to receive porcelain veneers--a comparison of three clinical techniques.

Objectives: Various techniques have been suggested to enable the operator to produce an even reduction of 0.5 mm of labial tooth enamel during preparation for a porcelain veneer. For example, in addition to the traditional free hand method, longitudinal or horizontal depth orientation grooves and the use of small round burs to produce dimples as depth guides have been suggested.

Stresses within porcelain veneers and the composite lute using different preparation designs.

Purpose: The purpose of this study was to investigate compressive and tensile stresses in porcelain and composite at the labial marginal region of porcelain veneer restorations using chamfer, shoulder, or knife-edge labial margin designs with labial window or incisal overlap incisal preparation designs.

Methods: Porcelain veneer models were constructed and loaded with (1) a 200-N, 45 degrees palatal load to simulate functional loading, and (2) a horizontal labial loading of 200 N to mimic trauma. Maximum tensile and compressive stresses were recorded within the labial marginal region of both porcelain and composite lute.

Assessing the quality of shoulder preparations for metal ceramic crowns.

Previous work by the authors indicates a tendency for academic clinicians to under prepare and over angle shoulder preparations for metal ceramic crowns. This has implications for the final restoration in terms of contour, appearance and strength. This study analysed ninety six preparations, forty eight in vitro and forty eight in vivo, performed by six clinicians.

Metal ceramic crowns--a review of tooth preparation.

The metal ceramic crown has become the most popular extra-coronal restoration in the armamentarium of the dentist, certainly within the UK. It combines the aesthetic qualities of porcelain with the strength of cast metal. This review discusses a number of issues relating to these crowns, and considers the principles of tooth preparation and marginal fit.

Reasons for referral of very elderly patients to the community dental service in rural England and the implications for developing oral health care services.

Objective: To analyse the medical conditions and dental treatment requirements.

Design: Retrospective analysis.

Setting: Rural South West Surrey, England.

Developing appropriate dental education systems: the impact of changes in oral health status and oral health care systems.

Current education programmes for oral health care workers have failed to adapt to the changing oral health status and the changing demands made upon oral health care systems. In order to adapt, education systems need to recognise the forces that are influencing the demands on the oral health care system and identify the most appropriate solutions. The most logical solution is to develop programmes which reflect the Primary Health Care Approach (PHCA), and in particular emphasise inter-sectorial collaboration.

Variation in labial shoulder geometry of metal ceramic crown preparations: a finite element analysis.

Recent studies have highlighted variations in the geometry of teeth prepared to receive metal ceramic crowns, particularly in the region of the labial shoulder, where shoulder designs have often involved less reduction than is recommended. Using two-dimensional finite element analysis, this study subjected crowns, superimposed upon preparations with clinically common labial margin designs, to loads of 200N in three different directions. The resultant stress distribution within the labial marginal porcelain was examined.

Assessment of shoulder dimensions and angles of porcelain bonded to metal crown preparations.

The metal ceramic crown is the most popular extracoronal restoration in the United Kingdom. These restorations may fail because of fracture or esthetics. A potential cause of failure is the quality and width of the facial shoulder preparation.

Progressive changes in the pulpo-dentinal complex and their clinical consequences.

With changes in the age structure and oral health in the population, changes in the pulpo-dentinal complex are becoming more relevant clinically. Age-related changes in the structure of dentine and pulp are reviewed. The influence of these changes on restorative dentistry are considered with particular emphasis on endodontics and the use of adhesive restorative materials.