Scientists at Plovdiv Medical University identify best materials for border molding in complete dentures fabrication

Edentulous jaw is a condition where either the upper (maxilla) or the lower (mandible) jaw is missing all teeth. In medical practice, it could be treated by placement of a complete denture. 

Previous research has already pointed that the application of a border molding procedure (or functional shaping) results in significantly fewer cases of pressure ulcers (decubitus) and soft tissues deformations, hence increased retention and stability of the prosthesis, both at rest and in function. Since there are many factors that affect the optimal treatment, such as anatomical structures (i.e. muscles, muscular and soft-tissue gripping) and the asymmetry between the left and right halves of upper and lower jaws, it is important that special care is taken to determine the depth, as well as the width of the tissue where the teeth would normally be nested (gingivobuccal sulcus). With border molding, it is possible to determine those, however, the accuracy of the impression would still largely depend on the materials used in the procedure.

Internal palatal surface (left) and side view (right) of the designed custom tray
Image: Dobromira Shopova, PhD

In their study, published in the open-access, peer-reviewed scholarly journal Folia Medica, Dr Dobromira Shopova and Prof. Diyan Slavchev at the Plovdiv Medical University (Bulgaria) sought to evaluate and determine the accuracy of two different groups of impression materials for border molding: thermoplastic and elastomers. They examined four different brands: Detaseal function (additive silicone for border molding), Sta-seal F (condensation silicone for border molding), GC Iso functional sticks (synthetic resin for border molding), Kerr Impression compound green sticks for border molding.

To perform their research, the team applied Dr Dobromira Shopova’s clinical method to measure negative pressure after border molding procedure, referred to as the vacuum measurement technique on edentulous upper jaw. They also assembled a special custom tray from a light-curing base plate with a palatal adapter. This was a 900, 7-millimetre metal adapter, which was fixed to the midline on the palatal slope. To create and measure the negative pressure, they used a combined pressure pump. The maximum value ​​was 3 bars for positive pressure and -1 bar for negative pressure.

Clinical setup of vacuum measurement after border molding of the custom tray of complete edentulous upper jaw
Image: Dobromira Shopova, PhD

Working protocol followed for all materials:

1. Apply the impression material along the edge of the individual tray;

2. Insert, position and perform Herbst functional tests;

3. Wait for the elasticity or hardening of the material;

4. Assemble the clinical unit for negative pressure measurement;

5. Measure the negative pressure that has been created between the custom tray and the prosthetic field, then record the result;

6. Release the individual impression tray from the patient’s mouth.

A statistically significant difference was observed between the two thermoplastic materials: the GC Iso functional sticks and the Impression compound green sticks. No statistically significant difference was observed between the other groups of materials. 

The measured mean negative pressure values ​​created between the prosthetic field and the custom tray showed close values ​​for each patient – with a difference of -0,05 to -0,1 bar. This showed that the anatomical features of the prosthetic field were of great importance.

In conclusion, quantitative measurement of negative pressure is entirely possible under clinical conditions. Thermoplastic materials for border molding are retained and formed only along the edge of the custom tray. However, silicone impression materials do not spread only on the edge of the custom tray, but also on the alveolar ridge, demonstrating their superior manipulative qualities and accuracy for the purposes of border molding.


Original source:


Shopova DA, Slavchev D (2020) Clinical Negative Pressure Measurement after Border Molding Procedure. Folia Medica 62(3): 578-584. https://doi.org/10.3897/folmed.62.e48464

Bulgarian Pharmaceutical Scientific Society’s journal moves to high-tech ARPHA platform

The established Pharmacia demonstrates a complete makeover in its new issue after signing with scientific publisher and technology provider Pensoft and its signature open-access platform

Launched by the Bulgarian Pharmaceutical Scientific Society in 1954, the open-access, peer-reviewed Pharmacia has been available online as full text since 2007. As of 2019, the journal moves to the fast-expanding portfolio of scholarly publisher and technology provider Pensoft. The journal’s 2019 inaugural issue and the first since the realisation of the new partnership is already live on the journal’s new website.

Homepage of Pharmacia‘s new website, https://pharmacia.pensoft.net

Thanks to the Pensoft’s signature open-access scholarly publishing platform ARPHA, Pharmacia demonstrates a complete makeover, including a modern and user-friendly interface in addition to a long list of high-tech perks, meant to ensure that published articles are easy to discover, access, cite and reuse by both humans and machines all over the world.

Furthermore, all users of the journal’s system: authors, editors and reviewers alike, are to greatly benefit of ARPHA’s integrated approach to the publication process. This means that once submitted each manuscript goes through the whole cycle: from review and copy/layout editing to publication, dissemination and archiving without leaving ARPHA’s collaboration-focused online environment.

One of the interesting features now available in Pharmacia is the article-level metrics available thanks to the partnership between ARPHA and the revolutionary discovery and analytics tools Dimensions and Altmetric. By searching through millions of research articles, grant applications, clinical trials, as well as policy documents, news stories, blogs and social media posts, they allow for each article’s references and citations in both the academic and the public sphere to be monitored in real time.

Continuing its tradition, the journal welcomes original research and review articles, preliminary and short communications (notes) on a wide range of topics within the pharmaceutical and related sciences. In addition, the journal also publishes conference reports, biographies and book reviews. Articles in Pharmacia are published in English and subjected to single-blind peer review.

Pharmacia‘s Editor-in-Chief Prof Plamen Peikov, comments:

“We have been looking forward to our collaboration with Pensoft and ARPHA, as it is certainly going to not only help modernise Pharmacia on the outside, but also make it more appealing to our authors and readers by building on the journal’s accessibility and global outreach. I believe that this nice step forward is already clearly evident in Pharmacia‘s latest issue.”

ARPHA’s and Pensoft’s founder and CEO Prof Lyubomir Penev says:

“I’m delighted to see this particular journal joining the Pensoft’s and ARPHA’s family,” says ARPHA’s and Pensoft’s founder and CEO Prof. Lyubomir Penev. “With our strong background in scholarly publishing, technology development and open science practices, I am certain that we are able to provide the right venue for a high-quality and enterprising journal like Pharmacia.”

What’s on in the new issue?

The creeping cinquefoil – a perennial plant from the Northern hemisphere – has its status as a traditional medicine for treating diarrhoea, haemorrhoids and bleeding gums confirmed in a collaborative ethnobotanical study by researchers at the Bulgarian Academy of Sciences and the Medical University of Sofia (Bulgaria). Further, the team, led by Irena Mincheva, seek to explore the suggested use of the plant against mastitis: a relatively common disease and a major cause for milk reduction in both people and dairy cows.

Another paper, authored by Dr Illya Podolsky and Sergiy Shtrygol from the National University of Pharmacy in Ukraine, adds new information about “the pharmacological nature” of a molecule already known as a promising antidepressant with a unique spectrum of additional properties. By conducting an experiment in rats, using the preferred Morris water maze assessment method, the scientists study the effects of Atristamine on spatial memory and learning.

Pharmacia‘s latest issue is available on the new website. Available in HTML, XML and PDF formats, the articles are easy to find, access, mine, reuse and cite by both humans and computers. Check out the issue at: https://pharmacia.pensoft.net/issue/1757/.

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Pharmacia is indexed byScopusAltmetricBiotechnobaseCAplusSM/Chemical AbstractsCNKICrossRefDimensionsEBSCOhostEmbase, ExtraMED, Google ScholarJ-GateMEDLINE/PubMedMendeleyMicrosoft AcademicNaviga (Softweco)OpenAIREPascalReadCubeToxcenterUnpaywall.

About the Bulgarian Pharmaceutical Scientific Society:

The Bulgarian Pharmaceutical Scientific Society was registered in 2003 with the aim to organise national and international science forums, support education and publish academic literature. Its main objectives are to organise and encourage pharmacological research and support collaboration between pharmacology professionals and related organisations on both national and global level.

New promising compound against heart rhythm disorders and clogged arteries

The pharmacological agent outperforms current drugs in most of cases, show multiple experiments

A new pharmacological agent demonstrates promising results for the prevention of a wide range of heart rhythm disorders, including both cardiac and brain injury-induced arrhythmias. Furthermore, the compound (SS-68) demonstrates significant activity in conditions of reduced blood flow to the heart caused by obstructed arteries.

The study, conducted by a research team led by Dr Saida Bogus of the Kuban State Medical University in Russia, is published in the open-access journal Research Results in Pharmacology.

Each year, more than 17 million people from around the globe (mostly Europe and the USA) die of cardiovascular diseases and related complications, according to the World Health Organization. In Russia, about 3 out of 1,000 people suffer from the most common and malignant heart rhythm disorder: atrial fibrillation (AF), where the count is expected to at least double in the next 30 years. While sometimes lacking symptoms, atrial fibrillation could generally be recognised by a racing, irregular heartbeat, dizziness, fatigue, shortness of breath and chest pain, thereby largely compromising the quality of one’s life. The disorder could also lead to various complications, including dementia, stroke and heart failure.

Currently, the drugs administered to AF patients have major deficiencies, including narrow therapeutic windows, which means that even minimal imprecision in the dosage could result in unacceptable toxicity. Hence, patients need to be closely monitored and have their doses adjusted on a regular basis.

In their study, the team turned to the aminoindole derivatives to look for an alternative compound. This chemical group has already shown a significant potential in terms of cardio-pharmacological activity.

Having tested the SS-68 compound on multiple occasions in different animals, the researchers report that it has a pronounced antiarrhythmic effect and is able to bring the electrical activity of the heart back to normal and, in most cases, outperforming the reference drugs used in clinical practice: amiodarone, lidocaine, aymaline, ethacizine, etmozine and quinidine anaprilin.

Further, in brain injury-induced arrhythmias, the compound was found to reduce the episodes of epilepsy. It was also observed to have a positive effect in clogged blood vessels where it is reported to have successfully increased the coronary blood flow. In addition, the compound managed to decrease the area of necrosis in the heart tissue caused by a heart attack.

“To date, there have been significant achievements of Russian and foreign pharmacologists, chemists and clinicians in creating and introducing into the practical medicine a number of antiarrhythmic drugs different by their chemical structure, nature, spectrum, activity and mechanism of action; nevertheless, one of the most important tasks of modern pharmacology is searching for and developing new highly active substances of the corresponding action,” explain the scientists.

“Special attention should be paid to an in-depth study of the molecular mechanisms of action of this compound,” they conclude.

A paper looking further into the molecular mechanisms of the antiarrhythmic action of SS-68 prepared by the same research team is currently in press with Research Results in Pharmacology.

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Original source:

Bogus SK, Galenko-Yaroshevsky PA, Suzdalev KF, Sukoyan GV, Abushkevich VG (2018) 2-phenyl-1-(3-pyrrolidin-1-il-propyl)-1 H-indole hydrochloride (SS-68): Antiarrhythmic and cardioprotective activity and its molecular mechanisms of action (Part I). Research Results in Pharmacology 4(2): 133-150. https://doi.org/10.3897/rrpharmacology.4.2859

 

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Research Results in Pharmacology is one of the journals hosted on ARPHA through the platform’s white-label publishing solution.