Bond Strength of a Novel Universal Resin Cement to Dentin with or without an Adhesive Bonding Agent: An In Vitro Study.

AIM: The purpose of this study was to evaluate the bond strength and fracture mode of universal resin cement to dentin compared to self-adhesive and adhesive resin cement with and without an adhesive bonding agent. MATERIALS AND METHODS: Seventy-two molar teeth were sectioned to expose coronal dentin, divided into three groups, and assigned to RelyX Universal (universal), RelyX Ultimate (adhesive), or RelyX Unicem 2 (self-adhesive) cements from 3M. The 3 groups were further subdivided into 2 subgroups of 12 specimens each, with or without the use of an adhesive bonding agent. Lithium-disilicate discs were bonded to the dentin surface using the cements, stored for 24 hours in distilled water, and subjected to 2,000 thermocycles before shear bond strength testing and fracture mode analysis. RESULTS: Significant differences in bond strength and fracture mode were found between groups based on cement or the use of a bonding agent. Both the universal and adhesive cements had significantly greater bond strengths to dentin with the use of a bonding agent versus no bonding agent. With the self-adhesive cement, there was no significant increase in bond strength to dentin with the use of a bonding agent. CONCLUSION: The novel universal resin cement had similar bond strengths to dentin as the adhesive cement with the use of a bonding agent, and similar bond strengths as the self-adhesive cement without the use of a bonding agent. The adhesively bonded universal cement had the greatest percentage of mixed and cohesive fractures. CLINICAL SIGNIFICANCE: When greater adhesion is needed clinically, the novel universal resin cement may be used with an adhesive bonding agent. However, when less adhesion is needed, it could be used without a bonding agent in self-adhesive mode.

Opioid overdose prevention training needs: Findings from emergency medical services providers in Baltimore County, Maryland.

Emergency Medical Services (EMS) providers are on the frontlines of the opioid response. This study explored the EMS training needs in Baltimore County, Maryland. An online survey conducted between January-June 2021 assessed knowledge, attitudes, awareness, and self-efficacy to use opioid overdose prevention strategies; burnout, compassion fatigue, stress, and wellness; and training needs among EMS providers (N = 256). Participants reported positive attitudes toward the use of opioid treatment guidelines and confidence in their ability to use the guidelines. They indicated positive attitudes toward harm reduction, but less favorable attitudes toward opioid use disorder (OUD). Although the participants understood the role of a peer recovery specialist moderately well, they were not fully comfortable with making a referral. They reported relatively low levels of burnout and compassion fatigue and good wellness practices, but indicated a moderate level of stress associated with COVID-19. Perceived training needs included: lifetime fitness and wellness, trauma-informed care, stigma awareness, stages of change, and harm reduction. Offering these trainings and enhancing EMS providers' comfort to make referrals to peer recovery support services may strengthen the referral systems and connect overdose survivors to a continuum of care.

A role for the pregnane X receptor in flucloxacillin-induced liver injury.

UNLABELLED: Drug-induced liver injury (DILI) due to flucloxacillin is a rare but serious complication of treatment. There is some evidence that flucloxacillin is a human pregnane X receptor (PXR) agonist. This study was designed to investigate the relevance of PXR to flucloxacillin toxicity and to identify genes changing in expression in response to flucloxacillin. Changes in gene expression in human hepatocytes after treatment with 500 microM flucloxacillin for 72 hours were examined by expression microarray analysis. The ability of flucloxacillin to act as a PXR agonist was investigated with reporter gene experiments. Flucloxacillin DILI cases (n = 51), drug-exposed controls without toxicity (n = 64), and community controls (n = 90) were genotyped for three common PXR polymorphisms. Luciferase reporter assays were used to assess the significance of a promoter region PXR polymorphism. Seventy-two probe sets representing 50 different genes showed significant changes in expression of 1.2-fold or higher. Most genes showing changes greater than 3-fold were known to be rifampicin-responsive, and this suggested a PXR-dependent mode of regulation. Using a luciferase-everted repeat separated by 6 base pairs element construct, we confirmed that flucloxacillin was a PXR agonist. We found a difference in the distribution of a PXR polymorphism (rs3814055; C-25385T) between flucloxacillin DILI cases and controls with the CC genotype associated with an increased risk of disease (odds ratio = 3.37, 95% confidence interval = 1.55-7.30, P = 0.0023). Reporter gene experiments showed lower promoter activity for the C allele than the T allele. CONCLUSION: Flucloxacillin is a PXR agonist at pharmacologically relevant concentrations, and a functionally significant upstream PXR polymorphism is a risk factor for flucloxacillin-induced DILI.

Flucloxacillin-induced liver injury.

Flucloxacillin is a common cause of drug-induced liver injury in Europe, affecting in the region of 8.5 in every 100,000 first time users of the drug. The mechanism by which the drug causes the liver injury is currently unknown but it is believed to be influenced by a combination of genetic and environmental factors. This review summarises what is currently known about the disposition of flucloxacillin in the liver, considers potential mechanisms by which flucloxacillin may cause the liver injury, and suggests candidate genes which could determine individual susceptibility to flucloxacillin-induced liver injury.