In vitro element release and biological aspects of base-metal alloys for metal-ceramic applications -

Abstract Objective The aims of this study were to investigate the release of element from, and the biological response in vitro to, cobalt–chromium alloys and other base–metal alloys used for the fabrication of metal-ceramic restorations. Material and methods: Eighteen different alloys were investigated. Nine cobalt–chromium alloys, three nickel–chromium alloys, two cobalt–chromium–iron alloys, one palladium–silver alloy, […]

Scientific Opinion on the safety of dental amalgam and alternative dental restoration materials for patients and users -

In the light of new developments and studies on dental amalgam a request was submitted by the Commission to update the SCENIHR opinion produced in 2008 on the safety and performance of both dental amalgam and possible alternatives, such as resin-based composites, glass ionomer cements, ceramics and gold alloys.

Evaluation of eye protection in occupational use of non-coherent optical sources -

Blue light and ultraviolet radiation can cause acute eye hazards. Further, increasing evidence suggests that blue light contributes to chronic diseases, such as cataracts and age-related macular degeneration. The use of optical radiation protective devices, such as goggles, is a simple means to avoid eye damage when working with high irradiance sources.

Influence of formulation on photoinactivation of bacteria by lumichrome. -

The aim of this study was to investigate the in vitro aPDT effect of various lumichrome pharmaceutical formulations

The effect of margin curvature on load at fracture of ceramic crowns -

The aim of this study was to use a clinically relevant test method to evaluate the effect of the curvature of the cervical crown margins on load at fracture

Cell toxicity of 2-hydroxyethyl methacrylate (HEMA): the role of oxidative stress -

In this study, the viability of human lung epithelial cells, BEAS-2B, was investigated after exposure to this monomer. Exposure to HEMA reduced the viability of the BEAS-2B cells as a result of increased apoptosis, interruption of the cell cycle, and decreased cell proliferation.

Relative Efficiency Of Ultraviolet Radiation A And B Combined With A Chemical Stressor On Zebrafish Embryos -

Organisms living in aquatic ecosystems may experience high doses of natural UV radiation. UV radiation penetrates the water column down to several meters. The penetration depth differs depending on the contents of particles, dissolved matter or pollutants. The aim of this study was to establish the dose-response relationship of phenotypic changes caused by UV.

Cements for gold inlays -

Gold inlays have for a long time been known as high quality restorations. Since dental amalgam is no longer applicable as filling material in Norway, the need for gold inlays has expanded, especially in patients having high chewing force and tooth abrasions who need replacement of their old amalgam fillings.

Improved antibacterial phototoxicity of a neutral porphyrin in natural deep eutectic solvents -

Neutral porphyrins for antibacterial photodynamic therapy (aPDT) have received little attention due to their tendency to aggregate in aqueous media and reports of low phototoxic effect. These compounds may be less toxic to cells than positively and negatively charged photosensitisers.

Patient satisfaction and complications of over-the-counter bleaching products -

To compare two home-based over-the-counter (OTC) bleaching tray products with similar hydrogen peroxide (HP) concentrations with respect to tooth lightening efficacy and potential to induce negative side effects in tobacco- and non-tobacco users as well as degree of satisfaction with product handling. The HP concentrations were near the regulation limit for bleaching products of 6% set by the European Union in 2011.

Safety of the use of bisphenol A in medical devices -

Bisphenol A (BPA) is a key building block of polycarbonate plastic and a precursor for the manufacturing of monomers of epoxy resins. The BPA exposure of the general population is via food as a result of the use of BPA in food packaging and via skin as a result of contact with thermal paper. The vast majority of the population (91–99%) has detectable levels of BPA-conjugates in their urine. BPA is also present in medical devices including implants, catheters, tubing, and some dental materials.

Placebo/nocebo -

Placebo was originally defined as an inactive medication giving a positive effect, whereas nocebo gives the opposite result. Both situations are based on expectations, of positive or negative kind.

Computer-controlled production of prosthetic constructions in the dental office – what are the quality requirements? -

With equipment for computer-aided design and manufacturing (CAD/CAM) in the dental office, the dentist again becomes his own dental technician. While the equipment itself is not subject to health-related regulation, the European Medical Devices Directive imposes requirements on the prosthodontic devices it produces

Appropriate eye protection filters prevent ocular damage -

A study was performed to assess 13 different eye protection filters, glasses and shields, intended for use with dental material light curing procedures as a follow- up to a similar investigation in 200

Chitosan – antibacterial use in dental materials -

Chitosan is produced commercially from crab and shrimp shell wastes with different degrees of deacetylation and molecular masses. Because of chitosan’s promising biological activities, including non-toxicity and antimicrobial activity, it is used for a variety of purposes in food production, medicine, agriculture, cosmetics, and biotechnology.

Guidance on the Determination of Potential Health Effects of Nanomaterials Used in Medical Devices -

This Guidance addresses the use of nanomaterials in medical devices and provides information for risk assessors regarding specific aspects that need to be considered in the safety evaluation of nanomaterials. According to the EU Recommendation for the definition of a nanomaterial (Commission Recommendation 2011/696/EU, EC 2011) any particulate substance with at least one dimension in the size range between 1 and 100 nm is considered a nanomaterial.

Appropriate eye protection filters prevent ocular damage from curing light -

A study was performed to assess 13 different eye protection filters, glasses and shields, intended for use with dental material light curing procedures as a follow-up to a similar investigation in 2006. To assess the safety and efficiency, spectra of curing lamps and filters were measured using a spectroradiometric instrument and integrating sphere.

Fluorescence characterization of dental plaque by hyperspectral imaging -

The buildup of dental plaque is the first step towards the oral diseases caries and periodontitis. Identification of pathogenic substances and matrix components is of importance when choosing an appropriate treatment plan. Hyperspectral imaging combines spectral- and spatial information, providing new possibilities for precise optical characterization of biological tissue [1,2], including dental plaque.

Importerte og norskproduserte tanntekniske arbeider – får vi det vi bestiller? -

Det settes søkelyset på forhold man kan stå overfor ved valg av tannerstatninger, om det er forskjell på et arbeid som er laget i Norge kontra et arbeid som er produsert i utlandet. To ganger tidligere (2008, 2010) er forholdet mellom oppgitt og analysert sammensetning av legeringselementene på importarbeid blitt undersøkt ved NIOM.

Ceramic Crown Margin Curvatures’ Effect on Fracture Strength -

Despite the high fracture strength of modern dental core ceramics, fracture is a common cause of failure in clinical trials. Fracture origins are typically in the crown margin in the appoximal region where the margin curves upwards. The scientific evidence for optimal marginal design of preparation is limited. The aim was to use a clinically relevant test method to evaluate the effect on strength of the cervical margin’s curvature of ceramic crowns.

Effect of different surface treatments and adhesives on repair bond strength of resin composites after one and 12 months of storage using an improved microtensile test method. -

To evaluate the effect of surface treatments and bonding systems on the repair bond strength between composite materials after one and 12 months of storage, using an improved microtensile test method.

Sub-lethal Concentrations of HEMA alter Protein Expression in Human Monocytes -

Several in vitro studies have shown increased intracellular level of reactive oxygen species (ROS) after exposure to 2-hydroxyethyl methacrylate (HEMA), a commonly used monomer in resin-based dental materials. This study aimed to investigate the initial changes of the proteome in a human monocyte cell line after exposure to HEMA by using Stable Isotope Labelling with Amino Acids in Cell culture (SILAC).

Ultraviolet Radiation and Multiple Stressor Effects on Zebrafish Embryos -

Pelagic embryos of fish may be exposed to high doses of natural UV radiation. Shortwave UV, UVB, as well as UVA may penetrate the water column to depths of several meters. The penetration depth differs depending on the contents of particles, dissolved matter or pollutants. Pollutants may also interact photochemically with UV- and visible radiation.

Nytt fra NIOM: Retningslinjer for lysherding i odontologi -

I mai 2014 deltok NIOM på et symposium ved Dalhousie University, Halifax, Canada om lysherding i odontologi. Det var 40 deltakerne fra ulike akademiske miljø og industrien, som utarbeidet retningslinjer for klinisk relevant valg og bruk av herdelamper (1)

Antibacterial fillings. Where are we today? -

Bacterial plaque adheres to resin based restorative materials to a larger extent than many other biomaterials, increasing the risk of secondary caries. Therefore, research has focused on adding antibacterial activity to such materials. One method has been to add soluble disinfectants such as chlorhexidine, benzalconium chloride, triclosan, octenidin, or antioxidants such as epigallocathechin to the […]

The influence of bis-EMA vs bis-GMA on the degree of conversion and water susceptibility of experimental composite materials -

The degree of conversion (DC) of mixtures with higher content of bis-EMA is affected by the presence of bis-GMA at lower energy density delivered from the curing device, suggesting that the restrictions caused by the presence of hydrogen bonds is dependent of the irradiation time used

Antibacterial phototoxic effects of synthetic asymmetric and glycosylated curcuminoids in aqueous formulations: studies on curcumin and curcuminoids. LIV. -

The aim of this study was to evaluate the in vitro phototoxic potential of synthetic asymmetric and glycosylated curcuminoids on planktonic model bacteria by counting the colony forming units.

Simulation of clinical fractures for three different all-ceramic crowns. -

Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes.

Formulation and characterisation of lyophilised curcumin solid dispersions for antimicrobial photodynamic therapy (aPDT) -

Curcumin is currently under investigation as a potential photosensitiser in antimicrobial photodynamic therapy (aPDT). Previous studies have demonstrated high phototoxicity towards Gram-positive (G+) bacteria, but lower effect on Gram-negative (G-) bacteria.

Photoinactivation of bacteria by lumichrome: Influence of formulation and preparation method. -

Lumichrome, a photodegradation product of riboflavin, is an endogenous compound in humans. The compound is more photostable and a more efficient photogenerator of singlet oxygen than riboflavin. It absorbs radiation in the UVA and blue light region, which can be an advantage in aPDT of superficial infections.

Formulation and characterization of lyophilized curcumin solid dispersions for antimicrobial photodynamic therapy (aPDT): Studies on curcumin and curcuminoids LII -

Bacterial resistance to antibiotics is increasing and alternative antibacterial treatments like antimicrobial photodynamic therapy (aPDT) are needed. Curcumin is under investigation as a potential photosensitizer in aPDT.

The effect of short curing time on chemical and mechanical properties of the composites -

The latest LED dental curing devices claim sufficient curing of restorative materials with short curing times. This study evaluates mechanical and chemical properties as a function of curing time of two commercial composite filling materials cured with three different LED lamps.

Biofilm formation on nanostructured hydroxyapatite-coated titanium. -

Biofilm formation on medical devices is a common cause of implant failure, especially regarding implants that breach the epithelial tissue, so-called transcutaneous implants. Nanotechnology and the development of new nanomaterials have given the opportunity to design nanotextured implant surfaces.

Leaching of monomers from bulk-fill composites -

This study investigated the leaching of monomers from bulk-fill composites, as well as some physical properties of the materials

Safe use of dental laser -

Laser is employed for a variety of tooth and oral treatments. Numbers from a national registry indicate that its use has doubled during the latest five years. This increase has occurred despite, in many instances, the lack of evidence of superior treatment outcome relative to conventional or other new treatments.

TEGDMA and filler particles from dental composites additively attentuate LPS-induced cytokine release from the macrophage cell line RAW 264.7 -

Due to incomplete curing and material degradation, cells in the oral cavity may be exposed to monomers and filler particles from dental composite fillings. The objective of the present study was to investigate if combined exposures to particles and a methacrylate monomer from composite fillings resulted in additive effects on the macrophage immune response.

Glass ionomer – a suitable restorative material in deciduous teeth? -

Traditionally, amalgam has been used for Class II restorations in primary teeth, but the use of amalgam has decreased in Scandinavia during the latest few decades, and now, amalgam has been banned in Norway and Sweden. Glass ionomer (GIC) adheres to tooth substance and has been a popular alternative to amalgam, but the traditional GIC products do not give as high longevity as amalgam in Class II restorations.

Fractures in dental ceramics: research and clinical experience -

The main problem with ceramics as biomaterials is that they are brittle. One focus of research and development has been on improving the materials’ fracture strength and thereby increasing the clinical success rates for dental, all-ceramic restorations. The most advanced dental ceramics should, according to in vitro testing, be able to withstand human mastication forces.

Cell toxicity of methacrylate monomers-the role of glutathione adduct formation. -

Polymer-based dental restorative materials are designed to polymerize in situ. However, the conversion of methacrylate monomer to polymer is never complete, and leakage of the monomer occurs. It has been shown that these monomers are toxic in vitro; hence concerns regarding exposure of patients and dental personnel have been raised.

Experimental investigation of the effect of surface roughness on bone-cement-implant shear bond strength. -

Debonding of cemented bone implants is regarded as a major contributor to complications. The relationship between shear bond strength and surface roughness has been investigated, however there are inconsistencies in the trends reported in different studies.