In Vitro Ability of a Novel Nanohydroxyapatite Oral Rinse to Occlude Dentine Tubules.

Objectives. The aim of the study was to investigate the ability of a novel nanohydroxyapatite (nHA) desensitizing oral rinse to occlude dentine tubules compared to selected commercially available desensitizing oral rinses. Methods. 25 caries-free extracted molars were sectioned into 1 mm thick dentine discs. The dentine discs (n = 25) were etched with 6% citric acid for 2 minutes and rinsed with distilled water, prior to a 30-second application of test and control oral rinses. Evaluation was by (1) Scanning Electron Microscopy (SEM) of the dentine surface and (2) fluid flow measurements through a dentine disc. Results. Most of the oral rinses failed to adequately cover the dentine surface apart from the nHa oral rinse. However the hydroxyapatite, 1.4% potassium oxalate, and arginine/PVM/MA copolymer oral rinses, appeared to be relatively more effective than the nHA test and negative control rinses (potassium nitrate) in relation to a reduction in fluid flow measurements. Conclusions. Although the novel nHA oral rinse demonstrated the ability to occlude the dentine tubules and reduce the fluid flow measurements, some of the other oral rinses appeared to demonstrate a statistically significant reduction in fluid flow through the dentine disc, in particular the arginine/PVM/MA copolymer oral rinse

The Efficacy of Selected Desensitizing OTC Products: A Systematic Review.

Licensed by the Creative Commons Attribution LicenseObjectives. The aim of the present study was to review the published literature in order to identify relevant studies for inclusion and to determine whether there was any evidence on the clinical effectiveness of selected desensitizing toothpastes, calcium sodium phosphosilicate (CSPS), amorphous calcium phosphate (ACP), nanohydroxyapatite, and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) on reducing dentine hypersensitivity (DH). Materials and Methods. Following a review of 593 papers identified from searching both electronic databases (PUBMED) and hand searching of relevant written journals, only 5 papers were accepted for inclusion. Results. Analysis of the included studies (3 CSPS and 2 ACP) would suggest that there may be some benefit for patients using these products for reducing DH. No direct comparative studies were available to assess all these products under the same conditions neither were there any comparative randomised controlled studies that compared at least two of these products in determining their effectiveness in treating DH. Conclusions. Due to the small number of included studies, there are limited clinical data to support any claims of clinical efficacy of these OTC products. Further studies are therefore required to determine the efficacy of these products in well-controlled RCT studies with a larger sample size

Quantification of Tooth Wear by Selected Desensitizing Polishing Pastes Using White Light Profilometry

Objectives: To analyse tooth wear using white light non-contact profilometry following the polishing of the tooth surface with selected polishing pastes. Methods: Three polishing pastes containing a range of particles sizes and different coarseness (extra-fine, medium, course) were compared with commercially available prophylaxis pastes (Nupro with Novamin® and Nupro with Fluoride) as controls. Particle size distribution was analysed using a using particle size analyser and quantified using Masterizer software. Teeth were in 70% ethanol prior to evaluation. 25 extracted human premolar teeth were distributed in five groups (n=5), and the teeth were mounted in a silicone putty matrix leaving an exposed buccal surface. White light profilometry with Proscan 2000 software was used to scan each tooth surface before and after polishing. Scantron ProForm software was used to superimpose images and measure surface loss and analyse the difference between the two surfaces-scans by the Proscan 2000 software. Results: Particle size analysis indicated that all samples consisted of a wide distribution of particles’ sizes (DX 10, 50, and 90). The course polishing paste had the largest DX 90 whereas Nupro with Fluoride had the lowest DX 90. The extra-fine pumice had the lowest DX 90, although this paste had larger values for DX 10 and DX 50 compared to the medium paste. The volume tooth loss analysis demonstrated that the course pumice had the most tooth surface loss compared to the extra-fine pumice which had the least amount of tooth surface loss. The average volume loss per group was 0.808, 0.022, 0.014, 0.022, 0.026 (course, medium, extra-fine, Nupro with Fluoride, and Nupro with Novamin®) respectively. Conclusions: The results indicated that the larger the DX 90 within the paste, the more tooth surface loss occurred due to the abrasivity of the paste. There was however minimal or no significant difference in the amount of tooth loss between the control polishing pastes

Dentine Tubule Occlusion by Novel Bioactive Glass-Based Toothpastes.

There are numerous over-the-counter (OTC) and professionally applied (in-office) products and techniques currently available for the treatment of dentine hypersensitivity (DH), but more recently, the use of bioactive glasses in toothpaste formulations have been advocated as a possible solution to managing DH. Aim. The aim of the present study, therefore, was to compare several bioactive glass formulations to investigate their effectiveness in an established in vitro model. Materials and Methods. A 45S5 glass was synthesized in the laboratory together with several other glass formulations: (1) a mixed glass (fluoride and chloride), (2) BioMinF, (3) a chloride glass, and (4) an amorphous chloride glass. The glass powders were formulated into five different toothpaste formulations. Dentine discs were sectioned from extracted human teeth and prepared for the investigation by removing the cutting debris (smear layer) following sectioning using a 6% citric acid solution for 2 minutes. Each disc was halved to provide test and control halves for comparison following the brushing of the five toothpaste formulations onto the test halves for each toothpaste group. Following the toothpaste application, the test discs were immersed in either artificial saliva or exposed to an acid challenge. Results. The dentine samples were analyzed using scanning electron microscopy (SEM), and observation of the SEM images indicated that there was good surface coverage following artificial saliva immersion. Furthermore, although the acid challenge removed the hydroxyapatite layer on the dentine surface for most of the samples, except for the amorphous chloride glass, there was evidence of tubular occlusion in the dentine tubules. Conclusions. The conclusions from the study would suggest that the inclusion of bioactive glass into a toothpaste formulation may be an effective approach to treat DH

Integrating Graduate Attributes with Assessment Criteria in Business Education Using an Online Assessment System

This paper describes a study of the integration of graduate attributes into Business education using an online system to facilitate the process. 'ReView' is a system that provides students with criteria-based tutor feedback on assessment tasks and also provides opportunities for online student self-assessment. Setup incorporates a process of 'review' whereby assessment criteria are grouped into graduate attribute categories and reworded to make explicit the qualities, knowledge and skills that are valued in student performance. Through this process, academics clarify and make explicit the alignment of assessment tasks to learning objectives and graduate attribute development across units and levels of a program of study. Its application in three undergraduate Business units was undertaken as a collaborative action research project to improve alignment of graduate attributes with assessment, identification of assessment criteria and feedback to students. This paper describes the use of Review and presents an analysis of post-ReView data that has institutional implications for improving assessment and self-assessment practices

The Effect of Loading of Bioactive Glass in Desensitizing Polishing Pastes on Tubular Occlusion

Objective: To determine 1) the most effective loading of the bioactive glass in a prophylactic polishing paste containing Bioactive glass particles that provides a more effective tubular occlusion and 2) the ideal application time required to achieve this objective using an in-office rotary cup with a fixed pressure and speed. Materials and Methods: 60 dentine discs were divided equally into 15 groups treated with 0%, 5.0%, 15.0% and 25.0% bioactive glass loading respectively and Nupro® at different applications (30, 60 and 120 seconds). Dentine permeability (Percentage flow rate) of each specimen was measured using a modified Pashley hydraulic conductance model at four different time points: (1) before toothpaste application, (2) after toothpaste application, (3) after saliva immersion and (4) after an acid challenge. Data were analysed by ANOVA to determine whether there were any significant differences with the control group (Nupro®) compared to the test groups at three different time intervals (30, 60 and 120 seconds). 20 dentine discs were analysed to observe the surface tubular occlusive effect following application of the various loadings at different times using scanning electron microscope (SEM). Results: There was an increased percentage fluid flow rate (FR) reduction with increasing bioactive glass loading (0.0%, 5.0%, 15.0%, 25.0%) compared to the control material Nupro®. The 25% bioactive glass loading was the most effective in reducing fluid flow at the various time points although there were no significant differences between the 15% and 25% glass loading. The 25.0% bioactive glass loading at 120 seconds also demonstrated effective tubular occlusion compared to the control prophylaxis paste. A comparison between the control and the various glass loadings at the various time points using SEM demonstrated increasing tubule occlusion with increasing time of application. Tubular occlusion also increased following artificial saliva immersion but decreased following an acidic challenge. Conclusions: Increasing the bioactive glass loading resulted in a greater fluid flow rate reduction with an increase of time of applications. Overall, the most effective application was with the 25% loaded bioactive glass at 120 seconds although the application of the 15% loaded bioactive glass prophylaxis paste for 30 seconds demonstrated effective tubular occlusion and fluid flow reduction

Bioactive Glasses in the Management of Dentine Hypersensitivity: A Review

Dentine Hypersensitivity is a common clinical condition, albeit of a low severity, and various in vitro and in vivo studies have been performed to test various approaches in managing the condition. This review investigates the use of bioactive glasses and their efficacy in treating Dentine Hypersensitivity. Significant progress was observed in the introduction of bioactive glasses in previous toothpaste formulations due to its ability to produce a Hydroxyapatite-like layer. Nevertheless, the results of the present review would suggest that a higher quality evidence was required to sufficiently support the use and effectiveness of bioactive glasses in treating Dentine Hypersensitivity. This observation is particularly pertinent in the absence of evidence relating to the effect of abrasivity of the glasses as well as the ability of strontium incorporation into the glasses. And the exact loading of the glass into dentifrice formulations. Overall, in vitro studies do appear to demonstrate that bioactive glass formulations may be an effective material to occlude dentine tubules which may in turn, reduce the fluid flow within the dentinal tubules and subsequently help manage Dentine Hypersensitivity

Air-Polishing in Subgingival Root Debridement: A Critical Literature Review

Aims: The objective of this literature review was to assess the new powders used in air polishing (AP) for subgingival debridement in terms of their debridement efficiency, effects on oral hard and soft tissues, and adverse effects. Also, to determine the disadvantages of this technique together with other relevant clinical considerations regarding its use. Methods: A literature search of five databases (PubMed, Scopus, The Cochrane Library, Web of Science, Embase) was conducted. The keywords used were air polishing, air abrasion, scaling, and subgingival debridement. This was supplemented with hand search of the bibliography or reference list of the relevant papers. Studies not reporting the full text in English, or not evaluating AP in the subgingival environment of natural tooth surfaces were excluded. Results: Of the 65 abstracts screened, 32 studies were included in the qualitative analysis. Several air polishing powders were assessed in terms of their debridement efficiency, effects on oral hard and soft tissues, and adverse effects. Conclusion: The current literature indicates that AP is a valid, highly efficient, and convenient treatment approach to subgingival debridement. It also appears to be superior to conventional treatment with respect to patient comfort, safety, and time efficiency. Moreover, air polishing with sodium bicarbonate appears to be the most abrasive procedure to both the soft and hard tissues in the oral cavity

Characterization of casein phosphopeptide-amorphous calcium phosphate based products with and without sodium fluoride

Aim: The aim of this paper was to characterize the active ingredients of ACP remineralizing pastes MI PasteTM and MI Paste PlusTM. Materials and Method: Two CPP-ACP containing products MI PasteTM and MI Paste PlusTM with addition of 900ppm sodium fluoride (NaF) supplied by GC America Inc. were evaluated. The free fluoride content of MIPaste PlusTM was quantified using a fluoride ion selective electrode (Orion 9609BN, 710A meter, South Burlington, VT, USA). 1.50 g of MI Paste PlusTM was dissolved thoroughly in 100 ml de-ionized water. Samples were prepared in duplicate. Ten grams of each product was weighed and mixed with 40ml of deionized water in a centrifuge tube. The solutions were vacuum filtered using a suction filtration setup, which consisted of a filter paper with pore size of 5-13 μm (Fisher Scientific, Loughborough), a Buchner funnel (250 ml, VWR, Leicestershire), a 500ml suction flask (Duran, Mainz) and a vacuum pump (KNF, Neuberger). The extracts were oven dried at 37°C for 24 hours prior to the further characterization by a combination usage of X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and 31P and 19F Magic Angle Spinning-Nuclear Magnetic Resonance (MAS-NMR). Results and Conclusions: The characterization of the extracts from MI PasteTM and MI Paste PlusTM clearly demonstrated varying degrees of the conversion of the ACP to apatite. A more significant conversion was observed in the MI Paste PlusTM with soluble fluoride. The fluoride ions bound to calcium and phosphate ions to form chemically stable fluorapatite, which resulted in a deficiency of mineral ions for remineralization, subsequently reduced the remineralization rate. The usage of sodium monofluorophosphate as an alternative to sodium fluoride could, however prevent this undesired conversion

Detailed characterization of a long-term rodent model of critical illness and recovery

Objective: To characterize a long-term model of recovery from critical illness, with particular emphasis on cardiorespiratory, metabolic, and muscle function. Design: Randomized controlled animal study. Setting: University research laboratory. Subjects: Male Wistar rats. Interventions: Intraperitoneal injection of the fungal cell wall constituent, zymosan or n-saline. Measurements and Main Results: Following intervention, rats were followed for up to 2 weeks. Animals with zymosan peritonitis reached a clinical and biochemical nadir on day 2. Initial reductions were seen in body weight, total body protein and fat, and muscle mass. Leg muscle fiber diameter remained subnormal at 14 days with evidence of persisting myonecrosis, even though gene expression of regulators of muscle mass (e.g., MAFbx, MURF1, and myostatin) had peaked on days 2–4 but normalized by day 7. Treadmill exercise capacity, forelimb grip strength, and in vivo maximum tetanic force were also reduced. Food intake was minimal until day 4 but increased thereafter. This did not relate to appetite hormone levels with early (6 hr) rises in plasma insulin and leptin followed by persisting subnormal levels; ghrelin levels did not change. Serum interleukin-6 level peaked at 6 hours but had normalized by day 2, whereas interleukin-10 remained persistently elevated and high-density lipoprotein cholesterol persistently depressed. There was an early myocardial depression and rise in core temperature, yet reduced oxygen consumption and respiratory exchange ratio with a loss of diurnal rhythmicity that showed a gradual but incomplete recovery by day 7. Conclusions: This detailed physiological, metabolic, hormonal, functional, and histological muscle characterization of a model of critical illness and recovery reproduces many of the findings reported in human critical illness. It can be used to assess putative therapies that may attenuate loss, or enhance recovery, of muscle mass and function