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 […]

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.

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.

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.

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.

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.

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.

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.

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)

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.
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.

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, […]

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.

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.

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.

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

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.

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’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.

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.

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 […]

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.

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

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.

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 […]

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

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.

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

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

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

This study aimed to investigate dentists’ treatment choices concerning “repair or replacement” of defective restorations.

The study aimed to explore the variability between the treatment decisions dentists make for MIH-affected teeth.

Abstract Objectives Chitosan is a carbohydrate polymer derived from chitin with a reported antimicrobial effect against bacteria. The present study aimed to investigate the biofilm inhibitory effect of methacrylated chitosan covalently incorporated into the polymethylmethacrylate polymeric network of a denture base resin. Methods Methacrylated chitosan was synthesized by reacting low molecular weight (LMW) chitosan with […]

Interference with bacterial quorum sensing communication provides an anti-virulence strategy to control pathogenic bacteria.

The purpose of this study was to investigate preparations of an anionic porphyrin, meso-tetra-(4-carboxyphenyl)-porphine (TCPP), solubilised in NADES, with regard to their physicochemical and antibacterial properties.

Abstract Medical polymers of biostable nature (e.g. polymethylmetacrylate, PMMA) are widely used in various clinical applications. In this study, novel PMMA-based composite bone cement was prepared. Bioactive glass (BAG) particulate filler (30 wt%) was added to enhance potentially the integration of bone to the cement. The polymer matrix was functionalized with trimethoxysilyl to achieve an interfacial […]

Reduction in the amount of glutathione (GSH) in cells can lead to increased sensitivity to physical and chemical agents. Methacrylate monomers (MM) are precursors of polymethacrylates which are used in dental and medical biomaterials and in a wide variety of other products. MM can increase cell sensitivity to long wavelength ultraviolet and visible radiation. The aim of this study is to elucidate if MM can induce sensitivity also to shorter wavelength radiation.

Powerful blue-light emitting dental curing lights are used in dental offices to photocure resins in the mouth. In addition, many dental personnel use magnification loupes.

Experiments using radial arm mazes show that mice and rats have difficulties finding food when their chewing capability is disturbed after molar extraction. Observations of this kind have indicated an association between mastication and cognition. Experimental evidence show increased blood stream and neuronal activity in young individuals using chewing gum. Some experiments also indicate that […]

It has been suggested that reactive oxygen species are involved in HEMA toxicity. The upregulated levels of antioxidant enzymes and Hsp70 family proteins showed that HEMA exposure lead to cellular stress at concentrations that had no effect on cell viability.