The dental monomer HEMA causes proteome changes in human THP‐1 monocytes -

Resin-based biomaterials are widely used in medical and dental treatment, and both clinicians and patients are exposed to the materials.
The present approach to analyzing the toxic potential of HEMA yielded information on interactions with living cells is not previously reported. This detailed information is of great value to make better predictions of possible side effects in the clinic.

Hvor god er du til å bestemme farge på restaureringene dine? -

Uttak av farge til fyllinger, kroner, broer og proteser av alle slag, er ofte en frustrerende øvelse. Men fortvil ikke, det ser ut til at de som praktiserer fargeuttak ofte og øver jevnlig, blir gode, uansett alder. Øvelse gjør mester

Peroxide-free tooth whitening products -

The purpose of this study was to compare the bleaching effects of peroxide-free and peroxide-containing tooth whitening products.
After 8 months, no perceivable lightening was noted for the peroxide-free products whereas the teeth treated with peroxide containing bleaching remained lightened.

Effect of methacrylated chitosan incorporated in experimental composite and adhesive on mechanical properties and biofilm formation. -

The results of this study show that methacrylated chitosan (CH-MA) may be incorporated into a composite and into an adhesive to reduce biofilm formation on their surfaces. The mechanical properties of the composite were challenged, but flexural strength measurements still met the requirement set in ISO 4049, whereas no differences were observed for the bonding properties of the adhesives.

The dental monomer 2-hydroxyethyl methacrylate (HEMA) causes transcriptionally regulated adaptation partially initiated by electrophilic stress -

The airways of dental personnel can be exposed to low concentrations of HEMA on a daily basis. Thus, we aimed to explore altered gene expression in a bronchial epithelial cell line after exposure to “non-lethal” concentrations of HEMA, demonstrated to be 2 mM or below in the current model system. We show that the expression of a number of genes was altered in HEMA exposed cells.

Opinions and Treatment Decisions for Dental Erosive Wear: A Questionnaire Survey among Icelandic Dentists -

Interest in dental erosive wear is increasing, and new recommendations of less invasive approaches to the treatment of the condition are emphasized. Therefore, the main objective of the present study was to identify dentists’ knowledge, beliefs, and clinical behaviour toward the condition. The present study is the first of its nature to analyze and permit comparison of the knowledge and treatment decisions of dental erosive wear between different countries, as it is conducted in a similar manner as the recent questionnaire study from Norway. The importance of making such intercountry assessments is high.

Bonding of Composite and Glass-ionomer to Amalgam -

Amalgam restorations of adequate standard and condition can very well be repaired with composite, but there should be provided for extra retention into the amalgam filling as the bond strength alone is not adequate. Glass-Ionomer may also be used for repair at amalgam restoration margins in not stress bearing areas, but as they do not adhere to amalgam, they need enamel and dentine for retention and possible undercuts towards amalgam interface.

Di-n-butyl phthalate modifies PMA-induced macrophage differentiation of THP-1 monocytes via PPARγ. -

The present study was part of the research project Inhalation and prenatal exposure to phthalates: influence on airway immunology, conducted at the Norwegian Institute of Public Health, and was funded by the Norwegian research council (Research grant number: 228129).

Digital evaluation of marginal and internal fit of single-crown fixed dental prostheses -

The adaptation of single-crown fixed dental prostheses (FDPs) is a subject of great interest in the research community. Many investigations have been published, and a variety of evaluation methods have been used to determine the fit accuracy of prosthetics.
Many of the methods required manual measurements of the gap between the restoration and the abutment. With the introduction of CAD/CAM techniques, digital tools started being used for evaluating the adaptation of FDPs.
In this study, a tabletop dental scanner was used. It is anticipated that in a clinical setting, an intraoral scanner is sufficient, at least for single-crown FDPs.

Biofilms and their properties -

Oral biofilm‐associated diseases, such as caries and periodontitis, represent global public health challenges. The diseases develop as a result of dysbiosis of the oral microbiome. There is a long tradition in medicine for treating bacterial infections by the use of antibiotics. Unfortunately, biofilm bacteria are significantly less sensitive to antibacterial agents than are their planktonic counterparts. This property of biofilm challenges us in our daily work as dentists, and might explain why many oral prophylactic agents predicted to be efficacious in vitro, only show marginal effect in vivo.

New animal model of extrinsic dental erosion-Erosive effect on the mouse molar teeth -

Human experiments on dental erosion are unethical because of the irreversible loss of dental hard tissues when exposed to acids. Therefore, studies using animal models are of high importance since they represent clinical situations. Based on the present results it can beconcluded that cola drink (phosphoric acid, pH=2.27) exhibited higher erosive effect on mouse mandibular molars compared to sports drink (citric acid, pH=3.39). This new animal model of extrinsic dental erosion where lesions of different severity can be created is suitable for further studies that will improve our understanding of the disease. The present method with transversely ground molars observed in SEM allows a registration of erosive lesions and lesion depths in small teeth like mouse molars. Both studies on the salivary influence (e.g. by using knockout mice) and the studies on the effect of fluoride on development of erosive lesions are warranted.

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.

Preparation and characterization of Bis-GMA-free dental composites with dimethacrylate monomer derived from 9,9-Bis[4-(2-hydroxyethoxy)phenyl]fluorene. -

New dimethacrylate monomer Bis-EFMA was synthesized and used to prepare Bis-GMA-free dental resin and composite materials. Studies of the experimental materials showed that Bis-EFMA-based resin matrix and composite materials had improved properties compared to Bis-GMA-based resin matrix and composite materials, respectively. Compared with the commercial dental composite material Z250, Bis-EFMA-based composite showed similar or improved properties except for a lower FS after water immersion. Based on the presented results, Bis-EFMA has potential to be used in commercial dental composites.

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.