The Effect of Variability in the Powder/Liquid Ratio on the Strength of Zinc Phosphate Cement

Aim. To investigate (a) variability in powder/liquid proportioning and (b) effect of variability on diametral tensile strength (DTS), in a zinc phosphate cement. Statistical analyses (α = 0.05) were by Student's t-test in the case of powder/liquid ratio and one-way ANOVA and Tukey HSD for pair-wise comparisons of mean DTS. The Null hypotheses were that (a) the powder-liquid mixing ratios would not differ from the manufacturer's recommended ratio (b) DTS of the set cement samples using the extreme powder/liquid ratios would not differ from those made using the recommended ratio. Methodology. 34 dental students dispensed the components according to the manufacturer's instructions. The maximum and minimum powder/liquid ratios, together with the manufacturer's recommended ratio, were used to prepare samples for DTS testing. Results. Powder/liquid ratios ranged from 2.386 to 1.018. The mean ratio (1.644) was not significantly different from the recommended value of 1.718 (P = 0.189). DTS values for the maximum and minimum ratios were both significantly different from each other (P < 0.001) and from the mean value obtained from the recommended ratio (P < 0.001). Conclusions. Variability exists in powder/liquid ratio for hand dispensed zinc phosphate cement. This variability can affect the DTS of the set material

Managing an ageing population: challenging oral epidemiology

Global population projections indicate that the proportion of older people is increasing and will continue to do so for the foreseeable future. Many countries are already experiencing the challenges of managing an ageing population, including increased pension contributions from workers, rises to national retirement ages, and spiralling healthcare costs. In oral health terms, in addition to simply an ageing population, epidemiological studies have demonstrated significant changes in the oral health of older adults in recent years. As the numbers of edentulous older adults has declined, there has been a significant increase in the number of partially dentate elderly. Changing attitudes, improved access to dental care and more effective preventative programmes have meant that large numbers of patients are now retaining natural teeth into old age. However, as older patients retain natural teeth for longer, the dental profession is charged with controlling chronic dental diseases in an increasingly challenging oral environment

Promoting co-production in the generation and use of research evidence to improve service provision in special care dentistry

Special care dentistry (SCD) provides holistic oral service provision for people with complex health and care needs. These can include physical, sensory, intellectual, mental, medical, emotional or social impairment or disability or, more often, a combination of these factors. The level of disability within these population groups can vary, and a proportion of people will have multiple and overlapping impairments and/or medical conditions. This paper explores a number of possible research methods that may better reflect the diversity and challenges of this population group, where the emphasis is placed on co-production and co-design

Lithium modulates autophagy in esophageal and colorectal cancer cells and enhances the efficacy of therapeutic agents in vitro and in vivo

Many epithelial cancers, particularly gastrointestinal tract cancers, remain poor prognosis diseases, due to resistance to cytotoxic therapy and local or metastatic recurrence. We have previously shown that apoptosis incompetent esophageal cancer cells induce autophagy in response to chemotherapeutic agents and this can facilitate their recovery. However, known pharmacological inhibitors of autophagy could not enhance cytotoxicity. In this study, we have examined two well known, clinically approved autophagy inducers, rapamycin and lithium, for their effects on chemosensitivity in apoptosis incompetent cancer cells. Both lithium and rapamycin were shown to induce autophagosomes in esophageal and colorectal cancer cells by western blot analysis of LC3 isoforms, morphology and FACS quantitation of Cyto-ID or mCherry-GFP-LC3. Analysis of autophagic flux indicates inefficient autophagosome processing in lithium treated cells, whereas rapamycin treated cells showed efficient flux. Viability and recovery was assessed by clonogenic assays. When combined with the chemotherapeutic agent 5-fluorouracil, rapamycin was protective. In contrast, lithium showed strong enhancement of non-apoptotic cell death. The combination of lithium with 5-fluorouracil or oxaliplatin was then tested in the syngenic mouse (balb/c) colorectal cancer model-CT26. When either chemotherapeutic agent was combined with lithium a significant reduction in tumor volume was achieved. In addition, survival was dramatically increased in the combination group (p 50% of animals achieving long term cure without re-occurrence (> 1 year tumor free). Thus, combination treatment with lithium can substantially improve the efficacy of chemotherapeutic agents in apoptosis deficient cancer cells. Induction of compromised autophagy may contribute to this cytotoxicity

Caries management using silver diamine fluoride and providing domiciliary dental care for dependent older adults: A qualitative study of Swiss dentists

OBJECTIVES Maintaining the oral health of dependent older adults is challenging, with limited access to dental care and limited focus on preventive oral health programmes. This study aimed to evaluate the attitudes of General Dental Practitioners (GDPs), working in Switzerland, to caring for dependent older adults with a focus on the use of silver diamine fluoride (SDF) as a caries preventive agent and more widely on the provision of domiciliary dental care (DDC). METHODS Seventeen GDPs working in Switzerland were interviewed. Each interview was semi-structured by a topic guide, digitally recorded, and transcribed. The transcribed data were analysed using a thematic analysis. RESULTS Three major themes to the widespread use of SDF in this population were identified: lack of basic knowledge including indications for use; aesthetic concerns and product availability. Those who had knowledge about the product believed that using it in the treatment of frail older adults had advantages, especially in the preservation and/or prolongation of the life of teeth without invasive treatments. The biggest barrier was its availability. The GDPs identified three major barriers related to DDC provision: lack of infrastructure, poor financial rewards and safety concerns (patient and operator safety). Those who provided this service stated that they were doing it because of self-motivation, kindness, or as a role in community service. CONCLUSIONS The potential use of SDF was viewed positively by the majority of the GDPs interviewed but confusion exists over its availability in Switzerland, and other barriers were identified to more widespread use in this patient group. The GDPs interviewed in this study reported that a lack of infrastructure and a low level of remuneration continue to be barriers to more of them undertaking DDC for dependent older adults

Putting guidelines into practice: Using co-design to develop a complex intervention based on NG48 to enable care staff to provide daily oral care to older people living in care homes

OBJECTIVES: (1) Explore the challenges of providing daily oral care in care homes; (2) understand oral care practices provided by care home staff; (3) co-design practical resources supporting care home staff in these activities. METHODS: Three Sheffield care homes were identified via the "ENRICH Research Ready Care Home Network," and three to six staff per site were recruited as co-design partners. Design researchers led three co-design workshops exploring care home staff's experiences of providing daily oral care, including challenges, coping strategies and the role of current guidelines. New resources were prototyped to support the use of guidelines in practice. The design researchers developed final resources to enable the use of these guidelines in-practice-in-context. FINDINGS: Care home staff operate under time and resource constraints. The proportion of residents with dementia and other neurodegenerative conditions is rapidly increasing. Care home staff face challenges when residents adopt "refusal behaviours" and balancing daily oral care needs with resident and carer safety becomes complex. Care home staff have developed many coping strategies to navigate "refusal behaviours." Supporting resources need to "fit" within the complexities of practice-in-context. CONCLUSIONS: The provision of daily oral care practices in care homes is complex and challenging. The co-design process revealed care home staff have a "library" of context-specific practical knowledge and coping strategies. This study offers insights into the process of making guidelines usable for professionals in their contexts of practice, exploring the agenda of implementing evidence-based guidelines