ADA: WHO releases report on dental materials, amalgam

American Dental Association - WHO releases report on dental materials, amalgam

Dental amalgam is rapidly fading out from dental practice due to the increased use of aesthetic restorative materials, particularly resin-based composites, for restorations in posterior teeth. However, the debate about the safety of dental amalgam seems to be a never-ending subject. Amalgam opponents go as far as to request this material to be banned due to the toxicity and health issues associated with mercury (oral lesions, autoimmune disorders, chronic illnesses etc.)

In a recent report, the World Health Organization (WHO) states that dental amalgam remains a dental restorative material of choice reaffirming the safety of this material. Nevertheless, the WHO report emphasizes that alternative materials and preventive measures should be further improved and implemented.

In 2009, ADA and FDA agreed that dental amalgam should not be restricted from dental practice since the scientific literature supports amalgam as "a valuable, viable and safe choice for dental patients". Read more about this in another post.

It seems that amalgam will eventually cease to be used in dentistry not because of its safety issues but because of considerable improvements of aesthetic materials.

Mineral Trioxide Aggregate (MTA): Free full text articles II

To see previously published list of free full text articles on MTA (part I), please click here.

Endodontics - Case reports
Unal GC, Maden M, Isidan T. Repair of Furcal Iatrogenic Perforation with Mineral Trioxide Aggregate: Two Years Follow-up of Two Cases. Eur J Dent. 2010 Oct;4(4):475-81.  

Yildirim T, Gencoglu N. Use of mineral trioxide aggregate in the treatment of large periapical lesions: reports of three cases. Eur J Dent. 2010 Oct;4(4):468-74.

Abarajithan M, Velmurugan N, Kandaswamy D. Management of recently traumatized maxillary central incisors by partial pulpotomy using MTA: Case reports with two-year follow-up. J Conserv Dent. 2010 Apr;13(2):110-3.

Chhabra N, Singbal KP, Kamat S. Successful apexification with resolution of the periapical lesion using mineral trioxide aggregate and demineralized freeze-dried bone allograft. J Conserv Dent. 2010 Apr;13(2):106-9.

Adiga S, Ataide I, Fernandes M, Adiga S. Nonsurgical approach for strip perforation repair using mineral trioxide aggregate. J Conserv Dent. 2010 Apr;13(2):97-101.

Ozbas H, Subay RK, Ordulu M. Surgical retreatment of an invaginated maxillary central incisor following overfilled endodontic treatment: a case report. Eur J Dent. 2010 Jul;4(3):324-8.

Araújo RA, Silveira CF, Cunha RS, De Martin AS, Fontana CE, Bueno CE. Single-session use of mineral trioxide aggregate as an apical barrier in a case of external root resorption. J Oral Sci. 2010;52(2):325-8.

Khatavkar RA, Hegde VS. Use of a matrix for apexification procedure with mineral trioxide aggregate. J Conserv Dent. 2010 Jan;13(1):54-7.

Mirikar P, Shenoy A, Mallikarjun GK. Nonsurgical management of endodontic mishaps in a case of radix entomolaris. J Conserv Dent. 2009 Oct;12(4):169-74.

Endodontics - scientific articles
Orosco FA, Bramante CM, Garcia RB, Bernardineli N, de Moraes IG. Sealing ability, marginal adaptation and their correlation using three root-end filling materials as apical plugs. J Appl Oral Sci. 2010 Mar-Apr;18(2):127-34.

Biocompatibility
Lessa FC, Aranha AM, Hebling J, Costa CA. Cytotoxic effects of White-MTA and MTA-Bio cements on odontoblast-like cells (MDPC-23). Braz Dent J. 2010 Jan;21(1):24-31.

Cintra LT, Bernabé PF, de Moraes IG, Gomes-Filho JE, Okamoto T, Consolaro A, Pinheiro TN. Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials. J Appl Oral Sci. 2010 Feb;18(1):75-82.

Chemical analysis
Han L, Okiji T, Okawa S. Morphological and chemical analysis of different precipitates on mineral trioxide aggregate immersed in different fluids. Dent Mater J. 2010 Oct 14;29(5):512-7.

Silorane technology in restorative dentistry - material properties and clinical application

I recently published a review article in the Serbian professional journal "Stomatolog" ["Dentist"] on Filtek Silorane material properties and clinical application steps. The article is in Serbian but I would be happy to translate it to English for interested colleagues. Contact me at vesna.miletic@gmail.com

Abstract

Polymerization shrinkage remains one of the main weaknesses of composite materials. Silorane technology significantly reduces material shrinkage compared to methacrylate composites. This review article compares chemical composition and polymerization process of methacrylate- and silorane-based composites. Systematically are reviewed studies on mechanical, aesthetic, antibacterial and chemical properties of Filtek Silorane, as well as its interaction with tooth tissues. Lower polymerization shrinkage and microbial adherence and comparable mechanical properties have been reported for Filtek Silorane compared to methacrylate-based composites. In the only clinical study that has been published so far, marginal adaptation of Filtek Silorane was found to be inferior than the nanocomposite Ceram.X  However, low inter-examiner reliability questions the results of this clinical study and scientific literature lacks more information on clinical performance of Filtek Silorane. 

Monomer elution from a dental composite

Recently, I started a series of studies on monomer elution from composites with colleagues from University of Belgrade School of Dentistry and Faculty of Technology and Metallurgy. One of these experiments was presented a month ago at an international material science and engineering conference YUCOMAT.

The nano-hybrid composite Filtek Z250 (3M ESPE) was used to study elution kinetics of monomers UDMA and HEMA over 28 days post-immersion in either distilled water or 75% ethanol. Kinetic models were proposed and it was shown that monomer elution followed the first order law for both UDMA and HEMA irrespective of the medium. However, there were some differences in that UDMA eluted more rapidly during the first 24 h and then much more slowly over the 28-day period. This indicates that during the first 24 h elution from the sample surface occurred whereas the slow phase corresponds to monomer elution from inside the polymer. On the other hand, HEMA did not start to elute immediately, but only after 24 h and the eluted concentrations increased over the 28 days. Though HEMA is not a genuine ingredient of the studied composite, its slow elution and small eluted amounts seem to support a previous statement by other authors that HEMA could elute as a product of degradation of UDMA. (We are currently investigating this hypothesis.)

Dental Materials Blog: Year 1

It has been a year since I started writing on this blog. During this first year, nearly 6700 visits and 12000 pageviews have been made by more than 5300 unique visitors. The average number of visits per day has been increasing constantly and currently is 17.70. What I am particularly proud is that one fifth of all visitors have returned and visited the blog more than once. Another important figure is that visitors come from more than 120 countries in the world (Figure 1.). The importance of this information is not so much related to the blog itself, but shows that in almost every corner of the Earth people search for dental information and want to expand their knowledge.

Figure 1. Map overlay

The most frequently visited posts are related to MTA in endodontics and the list of free full texts, self-adhering composite Vertise Flow and nano-filled, resin-modified glass ionomer Ketac N100. Likewise, the most frequently used keywords are "dental materials", ""MTA dental material", ""MTA dental", "mineral trioxide aggregate",  "Vertise Flow"...

Comments were disabled for most of the year, because I haven't noticed there was a problem, but a visitor drew my attention to it. Comments are now fixed and those received so far are all very positive.

I would like to encourage fellow researchers and clinicians to contribute to the Dental Materials Blog with their own posts, it is free and the choice of topics is entirely up to the authors.

Journal of Esthetic and Restorative Dentistry gets its first impact factor

A Miletic et al. study among the top 5 cited papers

In the latest list of SCI Journal Impact Factors 2009 published by Thomson Reuters, Journal of Esthetic and Restorative Dentistry is listed with the impact factor of 0.797. The Journal thanks all authors, reviewers and readers and allows free access to the top cited articles. Easy online submissions through ScholarOne Manuscripts are encouraged as this speeds up the review process. Hopefully, the Journal will maintain a growing influence in the scientific literature and increase its impact factor in the future.


It was a pleasure to see that one of the papers I did with my colleagues at the University of Belgrade School of Dentistry was among the top 5 cited articles in the Journal of Esthetic and Restorative Dentistry.

Miletic V, Ivanovic V, Dzeletovic B, Lezaja M.
Temperature Changes in Silorane-, Ormocer-, and Dimethacrylate-Based Composites and Pulp Chamber Roof during Light-Curing.

I look forward to submitting the results of my current studies to the Journal of Esthetic and Restorative Dentistry.

Recent books on dental materials II

The previous "Recent books" list on this blog is updated with, according to some scholars, the best book in this field.

Now in its ninth edition, Materials Science for Dentistry by Professor Brian W. Darvell (2009, 688 pages) continues its reputation as the most authoritative available reference for students of dentistry. It is also a valuable resource for academics and practitioners in the field. 

For more information about the book and the author, please visit publisher's website.