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PhD Studentship funded by GlaxoSmithKline

A study of de-and remineralisation model systems in conjunction with a number of analytical techniques to develop bacterial and non-bacterial model systems of occlusal caries to permit the isolation of anticaries active agents.
Unit of Plaque Related Diseases
School of Dental Sciences — University of Liverpool

Application deadline: 28 Sep 09

The Dental Materials Blog Team expands

Alexander A. Spriggs BSc joins the Dental Materials Blog

It is my pleasure to announce that Alexander A. Spriggs has joined the Dental Materials Blog. Alexander has a BSc Major in Biology and, at the moment, is pursuing second degree in Biochemistry while awaiting Dentistry acceptance at Dalhousie University, Halifax, NS, Canada.

In addition to his academic activities, Alexander owns and operates a construction company, Evolve Construction Services (http://www.evolveconstruction.ca/). It specializes in delivering environmental impact assessments along with construction services to suggest and execute a more environmentally sustainable project. He is conducting research for new solvents frequently used in the construction industry. The objective is to produce a specific solvent from non/low toxic materials that would eventually replace a current solvent on the market with a high toxicity.

Alexander is also doing a case study on Oral Health Care of Remote Populations: Nunavut, Canada, aimed at evaluating how isolated and remote communities suffer from dramatically different oral health standards when compared to more developed regions of the same country. Inclusive to this study was the aboriginal peoples of the remote province of Nunavut, Canada, and their understanding and application of modern medicine.

During 2007 Winter Semester, he presented an Industrial Microbiology Research Project for Dalhousie on the inception of Thymol into a breath mint to determine if the antimicrobial properties would be effective in improving oral health.

During the course of his education, Alexander has become competent in many laboratory techniques, such as:

• Agar plate preparation, inoculation, and experimentation on bacterial / fungal communities
• Bacterial staining / Slide preparation
• Recombinant DNA techniques
• Read and analyze most NMR print outs
• Microscope technique / operation

In addition, he is a skilled web designer, competent in web creation via HTML and PHP code. I’m sure the Dental Materials Blog will soon have a much nicer layout.

For Alexander’s full CV, you may contact him at a.spriggs@gmail.com

Research on tooth-bleaching agents by Dr Tatjana Savic-Stankovic BDS, MSc

Dr Tatjana Savic-Stankovic BDS, MSc, my colleague and friend from the University of Belgrade School of Dentistry, completed an extensive study for her MSc thesis on tooth-bleaching agents.

Dr Savic-Stankovic defended her MSc thesis in a viva but also presented the highlights of her research at the School of Dentistry Anniversary in June 2009. Click on the image to enlarge the poster. Since the poster is in Serbian, the abstract in English is given below. Copyright belongs to Dr Savic-Stankovic. For further contact, please use the email address savic.t@nadlanu.com

The effect of different concentrations of bleaching agents on enamel properties in vitro and clinical efficiency of the „walking bleach“ technique

Dr Tatjana Savic-Stankovic BDS, MSc

Introduction. Bleaching results in slow transformation of organic substances into chemical intermediary products which are lighter than the original. Bleaching efficiency is related to the cause of tooth discoloration.

Aims. To evaluate changes in enamel microhardness and morphological aspects of enamel after treatment with different concentrations of bleaching agents. The aim of the clinical study was to evaluate the bleaching efficiency with regard to the cause of discoloration: trauma, necrosis, endo-sealer or unknown.

Materials and Methods. Twenty freshly extracted sound human molars were treated with 10%, 20% and 35% carbamide peroxide and 38% hydrogen peroxide (Opalescence gel, Ultradent. Pro.) in clinically recommended intervals. Knoop microhardness measurements were performed at baseline and 8 hours, 21 days and 3 weeks post-treatment. SEM was used to evaluate morphological changes in enamel post-treatment.

Forty non-vital central incisors were bleached using sodium perborate and hydrogen peroxide mixture which was changed weekly. Based on patients' dental history and clinical examination, discolored teeth were allocated to four groups depending on the cause of discoloration: trauma, necrosis, endo-sealer and unknown. Aesthetic results of the applied “walking bleach” technique were evaluated before and after treatment using the standardized colour-coded key for colour comparison.

Results. No statistically significant differences and no changes in enamel surface morphology were observed between 10% and 20 % carbamide peroxide groups. A significant decrease in enamel microhardness was found in 35% carbamide peroxide and 38% hydrogen peroxide groups. Mild and moderate changes in enamel surface morphology were observed in the group treated with 35% carbamide peroxide whilst substantial changes were found in the group treated with 38% hydrogen peroxide.

The shortest treatment (15.7 days) and greatest number of shades before and after bleaching were found in patients whose aetiological factor for discoloration was „trauma”. Bleaching efficiency decreased with age. No correlation was found between bleaching efficiency and the initial shade.

Conclusions. Increasing concentrations of tooth-bleaching agents resulted in lower enamel microhardness values and more profound changes in enamel surface morphology. The cause of tooth discoloration had a significant effect on the clinical efficiency of the "walking bleach" technique.

Keywords: dental materials, tooth bleaching, tooth whitening, carbamide peroxide, hydrogen peroxide, enamel, clinical trial, walking bleach

IADR-CED with NOF & ID Conference, Munich, Sept 9-12, 2009

The 44th Conference of the Central European, Scandinavian and Israeli Divisions of IADR


The scientific programme includes several oral sessions, poster presentations and workshops. There will be several dental materials symposia:

• Zirconiumdioxide restorations and reasons for failures
• New composite formulations
• Self adhesive cements

More than 400 studies will be presented at the Conference. Complete programme and author index can be found HERE.

Two of my students, Ana Ergic and Dejan Nedeljkovic, will present our study entitled "Surface characterisation of resin-based composite materials using atomic force microscopy". The poster will be uploaded to this blog after the conference.

Journal of Dentistry: Top 10 Hottest articles

The list of Top 10 Hottest articles, most frequently downloaded from Journal of Dentistry is regularly published on this journal's website. The latest list can be found HERE.

Eight out of ten most downloaded articles are related to dental materials. The single most popular article is the review of the effect of polyphenols on oral health and disease. The most popular field represented by the greatest number of articles (4) in the Top 10 seems to be the bleaching of teeth. The most popular research article is a study on the effect of different adhesive systems and laser treatment on the shear bond strength of bleached enamel.

Journal of Dentistry is a SCI journal, published monthly, with the current impact factor of 2.033.

Latest jobs in dental materials science

PhD Studentship

The Impact Of Titanium Accumulation On Peri-Prosthetic Soft Tissue Outcomes

School of Dentistry , College of Medical and Dental Sciences — University of Birmingham

Application deadline: 07 Sep 2009

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I'd like to add a personal remark that this post offers an opportunity to work with one of the most competent dental material scientists, Dr Owen Addison, in an intellectually stimulating scientific environment at the University of Birmingham School of Dentistry.

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NB. I'm proud to announce that more jobs related to dental materials will be posted on this blog with permission from jobs.ac.uk. For information on other jobs, visit www.jobs.ac.uk and check out blogs by their resident bloggers who share experiences of jobseeking, academic life and more.

BSDR Conference in Glasgow

As previously announced, the BSDR Conference is taking place in Glasgow. The Santini Miletic Research Group presented a study entitled "The ratio of carbon-carbon double bonds in different BisGMA/HEMA mixtures". Click on the image.
Prior to the poster session, I attended the Ceramics session chaired by professor Richard Van Noort. Several very interesting studies were presented regarding CAD-CAM ceramic strength, ceramic reinforcements, fluoride-containing bioactive glasses, leucite glass-ceramic crystallisation, coating materials for zirconia ceramics and wear quantification using profilometry. It was quite impressive to see the very high standard of research carried out at various universities in the UK.

Sponsored by 3M ESPE, the Dental Materials Group Symposium was held during the afternoon session. After the opening remarks by Dr Garry Fleming and Professor R. Van Noort, lectures were given by Dr Rainer Guggenberger (The chemistry of new resin systems), Professor David Watts (The measurement of shrinkage and contraction stress), Professor Tim Watson (The quality of adhesion) and Professor Trevor Burke (Early thoughts of clinical experience using the novel silorane-based composite material). The lectures increased our knowledge on various aspects of resin-based composites and the silorane-based material in particular. The 'non-shrink' resin composites are still not a reality but dental technology has made substantial improvements towards this goal.