Optimizing quality and safety of dental materials -

Optimizing quality and safety of resin‐based materials need coherent strategies. Proper handling and polymerization increase the rate of conversion and thus minimize the content of residual monomers. Measures to reduce biofilm accumulation at the tooth‐restoration interface could prevent or reduce the most common reason for restoration failure, recurrent caries.

Presence and leaching of bisphenol a (BPA) from dental materials -

BPA has been reported to leach from some resin-based dental restorative materials and materials used for orthodontic treatment. To confirm and update previous findings, especially in light of the new temporary lower threshold value for tolerable daily BPA intake, leaching of BPA from 4 composite filling materials, 3 sealants and 2 orthodontic bonding materials were investigated.

Nrf2 Signaling and Cytoprotection in Human Epithelial Airway Cells Exposed to HEMA -

Methacrylates are common constituents of resin-based biomaterials. These materials cure by polymerization of methacrylate monomers, but incomplete polymerization causes leakage and patient exposure to the electrophile monomers.

Lysherding – så enkelt og så vanskelig. -

For kort herdetid kan føre til mangelfull herding (polymerisasjon) av komposittmaterialer. For lang herdetid kan øke risiko for varmeskade på oralt bløtvev og pulpa. Herdelampens lysstyrke (irradians) reduseres når avstanden øker mellom lysutgangen og materialflaten.
For å opprettholde lysdosen som kreves for tilstrekkelig herding, må herdetiden økes. Kortere lysherdingstider enn omtrent 10 sekunder kan føre til utilstrekkelig herding av materialet.

Side effects of chemical compounds used in dental clinics -

The work at a dental clinic implies getting in contact with different chemical substances, which may cause temporary or permanent injury to the staff, primarily allergic reactions, but also local irritation, carcinogenic or toxic effects. Dentists and dental assistants belong to the professional groups most frequently experiencing work-related eczema.

Redefining the Phenotype of Dental Caries -

To our knowledge, this is the first study to separate patients into more discrete groups based on dental caries experience defined from longitudinal data and the first to study acute increases in DMFT score between two time points. Our hope with doing so is to provide more power in our predictions of genetic influences of dental caries and perhaps lead to better ways of studying the disease based on more specific categorizations of phenotypes.

A retrospective clinical study on the longevity of posterior Class II cast gold inlays/onlays. -

All dental restorations have a limited lifespan and will eventually need to be repaired or replaced. It is important to have in mind that the longevity of gold restorations have not been shown to be superior to that of resin composite, which should still be the first material of choice. However, gold inlays could be considered when the right indications are present.

Taste and smell perception in aging (Aldring, smak og lukt) -

Taste and smell are senses reacting upon solutes from food and breathing air conveyed by the cranial nerves. Normal aging includes cellulary and extracellulary biochemical mechanisms detrimental to neurons in the central nervous system, including those processing taste and smell signals. Aging also means reduction of the number of taste buds in the oral cavity and of the number of odor receptors in the nasal mucosa.

Antibacterial Activity of Endodontic Sealers against Planktonic Bacteria and Bacteria in Biofilms. -

Antibacterial activity of 4 endodontic sealers against bacteria planktonic grown or in biofilms commonly detected from persistent and secondary endodontic infections.
Investigating the antibacterial activity of endodontic sealers and materials against bacteria in biofilms is highly important to evaluate the materials’ ability to eradicate bacteria from the infected root canal

Survival of extensive restorations in primary molars: 15-year practice-based study. -

Caries decline in the western world is accompanied by strong polarization among children; 8% of Finnish 5-year-olds having 76% of untreated caries. This high caries risk group needs preventive and restorative strategies.
Severely affected primary molars of children at high caries risk are better managed, using PMCs to optimize the resources in public oral health services.

Role of Proteolytic Enzyme Inhibitors on Carious and Eroded Dentin Associated With a Universal Bonding System -

Abstract Objectives: The aim of this study was to evaluate the effect of proteolytic inhibitors on the bond strength of a universal adhesive system (etch-and-rinse mode) applied to artificial carious and eroded dentin. Methods: Ninety molars were prepared and randomly divided into three groups according to the substrate: N, no challenges; ACD, artificial carious dentin […]

Internal fit of three-unit fixed dental prostheses produced by computeraided design/computer-aided manufacturing and the lost-wax metal casting technique assessed using the triple-scan protocol -

Suboptimal adaptation of fixed dental prostheses (FDPs) can lead to technical and biological complications. It is unclear if the computer-aided design/computer-aided manufacturing (CAD/CAM) technique improves adaptation of FDPs compared with FDPs made using the lost-wax and metal casting technique.

Komposittmaterialer – utlekking av monomer og cytotoksisitet -

NIOM har på oppdrag fra Helsedirektoratet undersøkt fire komposittmaterialer: ett Own Brand Label (OBL)-materiale, to bulk-fill materialer og et mye benyttet universalmateriale. Det ble funnet ubetydelige forskjeller i utlekket monomer mellom produktene. I en cytotoksisitets-screening med ekstrakter fra produktene var det noe forskjell mellom materialene. Ytterligere molekylærbiologiske undersøkelser viste imidlertid ingen indikasjon på celleskade. Basert på disse undersøkelsene kan ingen av produktene bedømmes som mindre sikre enn de andre.

Kontrol og bekæmpelse af dental biofilm -

Control and eradication of dental biofilm. This article gives a brief overview of antimicrobial compounds used for biofilm control and new technologies and strategies to combat dental biofilms.

SCHEER: Preliminary Opinion on the potential risks to human health of Light Emitting Diodes (LEDs) -

The Scientific Committee on Health, Environmental and Emerging Risks of the European Commission released the Preliminary Opinion in July. The Opinion was open for comments until September. NIOM scientist, Ellen Bruzell, served as external expert in the preparation of the Preliminary Opinion.

Is dental erosive wear a common condition among 16-year-olds in Troms, Norway? -

The aim of the present study was to investigate the prevalence, distribution and severity of dental erosive wear among 16-year old adolescents living in Troms. Clinical, intra-oral pictures of 392 individuals involved in the «Tromsø undersøkelsen, Fit Futures» were evaluated for dental erosive wear by three previously calibrated examiners.

Effect of curing and silanizing on composite repair bond strength using an improved micro-tensile test method -

To evaluate the micro-tensile repair bond strength between aged and new composite, using silane and adhesives that were cured or left uncured when new composite was placed.

Water sorption and solubility of polyamide denture base materials -

Some patients experience adverse reactions to poly(methyl methacrylate)-based (PMMA) dentures. Polyamide (PA) as an alternative to PMMA has, however, not been well documented with regard to water sorption and water solubility. The aim of this in vitro study was to measure water sorption and water solubility of two PA materials compared with PMMA, and to evaluate the major components released from the PA materials and the effect on hardness of the materials.

Kemiske stoffers skadevirkninger på tandklinikker (Side effects of chemical compounds used in dental clinics) -

The work at a dental clinic implies getting in contact with different chemical substances, which may cause temporary or permanent injury to the staff, primarily allergic reactions, but also local irritation, carcinogenic or toxic effects. Dentists and dental assistants belong to the professional groups most frequently experiencing work-related eczema. The chemical substances may originate from dental materials, such as mercury from amalgam and monomers from resin based materials. The substances may be released during preparation, polishing and removal of restorations. In addition, different biocides/chemical disinfectants are used for both clinical an infection control purposes. (Article in Danish)

Brug af fysiske værnemidler på tandklinikker (Use of physical protective equipment at dental clinics) -

Members of the dental team are exposed daily to biological, chemical and physical agents. These vary for example, from microorganisms to noise, and are present in forms as diverse as aerosols and gasses. National and international directives, legislation and guidelines for infection control, and occupational health issues intended for the dental clinic, govern the physical and other types of protection required. In addition, it is important to be acquainted with the justification for any specific protective item, when and when not to use it and when an upgrade is required. (Article in Danish)

Bacterial biofilm elimination using gold nanorod localised surface plasmon resonance generated heat -

Bacterial biofilm elimination using gold nanorod localised surface plasmon resonance generated heat.
Highlights:
A technique for antibiotic replacement using heat for biofilm elimination is proposed.
Gold nanorods exhibit localised surface plasmon resonance upon optical irradiation and when relaxing, absorbed energy is dissipated as heat, which is utilized to kill bacteria.
After 5 minutes of near infrared irradiation an average of 71% of early biofilms were eliminated.

Investigation of the antimicrobial effect of natural deep eutectic solvents (NADES) as solvents in antimicrobial photodynamic therapy -

Abstract Natural deep eutectic solvents (NADES) are a third class of liquids, separate from water and lipids. Some NADES, especially those containing organic acids, have been suggested to possess antimicrobial properties. Such properties may be advantageous when NADES are used as solvents in e.g. antimicrobial photodynamic therapy. However, to control the toxicity of acid-containing NADES, […]

A novel etching technique for surface treatment of zirconia ceramics to improve adhesion of resin-based luting cements -

Bonding of zirconia crowns and bridges to abutments is important, not only bonding of the thin resin layer to the abutment, but also bonding to the zirconia ceramic is crucial. Both mechanical and chemical adhesion are desired. Mechanical retention of dental porcelain achieved by etching with moderately concentrated hydrofluoric acid is not possible with zirconia ceramics. The purpose of this study was to show that etching is possible with relative low melting fluoride compounds such as ammonium hydrogen difluoride and potassium hydrogen difluoride.

Relation between In Vitro Toxicity and the Thiol-Reactivity of Methacrylates in Resin-Based Biomaterials -

In this study we aimed to further map the suggested relation between GSH-depletion and methacrylate toxicity by comparing the molecular effects of methacrylate exposure and GSH-depletion by inhibiting GSH-synthesis.

Leakage of Bisphenol A from Dental Materials -

We are daily exposed to a variety of chemicals. One example is the chemical Bisphenol A (BPA). Animal studies indicate that BPA has effects on liver, kidney and breast tissue. Possible endocrine disruption effects contribute to uncertainty around BPA.

The dental monomer hydroxyethyl methacrylate (HEMA) counteracts lipopolysaccharide-induced IL-1β release-Possible role of glutathione. -

HEMA reduced GSH levels and decreased IL-1β release from LPS-stimulated macrophages. The role of GSH in the regulation of IL-1β release was explored. GSH depletion alone could not explain the attenuation of LPS-induced IL-1β release. Electrophile reactivity toward other cellular molecules is a new working hypothesis

Light curing procedures – performance, knowledge level and safety awareness among dentists -

The study aimed to investigate dentists’ exposure to curing light and to obtain information about the dentists’ knowledge on practical use and technical features of their curing lights as well as their safety awareness.

Oral mikroflora – et reservoir av antibiotikaresistensgener? -

One of the most significant medical achievements in human medicine during the 20th century was the discovery and introduction of antibiotics. However, a short time after the introduction of new antibiotic compounds, resistant bacteria were discovered.

NIOM – Fortyfive years of Nordic dentistry -

NIOM’s purpose is to ensure that the dental materials and products, used in dental care in the Nordic countries, meet the health and technical requirements which are in place regarding development in the area.

How do resin composites perform in the long run? -

Restorative dental treatment still lays claim to a large proportion of dentists’ working day. After the phase-out of amalgam as a restorative material, composite resin has become the dominating material of choice among dentists.

Composite restorative materials – basic properties -

Abstract In this article we are looking at the development of composite restorative materials. We discuss the composition of the resin matrix, and describe the introduction of some new monomers. We also comment on the development of fillers. Some materials are discussed in more detail. Bulk-fill materials do not seem to be essentially different to […]

Endodontic materials – irrigants, sealers, and obturating materials -

The root canal filling concludes the classical triad in endodontic treatment: biomechanical instrumentation, disinfection and obturation. The purpose of the root canal filling is to prevent penetration of bacteria into the root canal and to prevent access of nutrients and growth of residual bacteria.

Dental ceramics – Classification and properties -

Different dental ceramics available today including a classification, mechanical properties and a description of processing techniques with emphasis on the zirconia materials.

Base metal alloys for fixed prosthodontics -

Cobalt-chromium alloys are now commonly used for fixed dentures and single crowns. The alloys are attractive because they are light and provide high stiffness due to their high elastic modulus (Young’s modulus) compared with noble metal alloys, pure titanium or titanium alloys.

The influence of dental loupes on the ocular hazard. -

Abstract The use of dental and surgical loupes is increasing in odontology and medicine. During dental treatments this use is often combined with bright blue light sources such as from dental material curing lights and/or lights attached to the loupes. By the aid of an experimental model we investigated whether the time to reach the […]

Dentale restaureringsmaterialer: Biologiske egenskaper og deres kliniske konsekvenser -

Tandrestaureringsmaterialer indeholder en mængde forskellige stoffer med ulige biologiske egenskaber. I mundhulen udsættes materialerne for både mekaniske, kemiske, mikrobielle og enzymatiske påvirkninger, og substanser kan frigives fra materialerne

Internal fit of single crowns produced by CAD/CAM and lost-wax metal casting technique assessed by the triple-scan protocol -

Whether single crowns produced by computer-aided design and computer-aided manufacturing (CAD-CAM) have an internal fit comparable to crowns made by lost-wax metal casting technique is unknown.

Degree of conversion and leached monomers of urethane dimethacrylate-hydroxypropyl methacrylate-based dental resin systems. -

The degree of conversion (DC) and monomer leaching of three experimental urethane dimethacrylate (UEDMA)-hydroxypropyl methacrylate (HPMA)-based resin systems were studied.

Er probiotika relevant for oral helse? -

Mange forskere hevder at regelmessig tilførsel av probiotika også kan ha en hemmende effekt på kariesutvikling og periodontal patologi ved at tilførte bakterier konkurrerer med patogener både med hensyn til adhesjon, næringsstoffer og vekstfaktorer

Antibacterial and Antibiofilm Effect of Low Viscosity Chitosan against Stapylococcus epidermides -

The aim of this study was to investigate the antibacterial and antibiofilm properties of low viscosity chitosan on S. epidermidis growth and biofilm formation.