Effectiveness of composite cure associated with different curing modes of LED lights

This study compared the effectiveness of cure of two LED (light-emitting diodes) lights (Elipar FreeLight [FL], 3M-ESPE; GC e-Light [EL], GC) to conventional (Max [MX], Dentsply-Caulk [control]), high intensity (Elipar TriLight [TL], 3M-ESPE) and very high intensity (Astralis 10 [AS], Ivoclar Vivadent) halogen lights. The 10 light-curing regimens investigated were: FL1 400 mW/cm2 [40 seconds], FL2 0-400 mW/cm2 [12 seconds] --> 400 mW/cm2 [28 seconds], EL1 750 mW/cm2 [10 pulses x 2 seconds], EL2 350 mW/cm2 [40 seconds], EL3 600 mW/cm2 [20 seconds], EL4 0-600 mW/cm2 [20 seconds] --> 600 mW/cm2 [20 seconds], TL1 800 mW/cm2 [40 seconds], TL2 100-800 mW/cm2 [15 seconds] --> 800 mW/cm2 [25 seconds], AS1 1200 mW/cm2 [10 seconds], MX 400 mW/cm2 [40 seconds]. Effectiveness of cure with the different modes was determined by measuring the top and bottom surface hardness (KHN) of 2-mm thick composite (Z100, [3M-ESPE]) specimens using a digital microhardness tester (n=5, load=500 g; dwell time=15 seconds). Results were analyzed using one-way ANOVA/Scheffe's post-hoc test and Independent Samples t-test (p<0.05). At the top surface, the mean KHN observed with LED lights ranged from 55.42 +/- 1.47 to 68.54 +/- 1.46, while that of halogen lights was 62.64 +/- 1.87 to 73.14 +/- 0.97. At the bottom surface, the mean KHN observed with LED and halogen lights ranged from 46.90 +/- 1.73 to 66.46 +/- 1.18 and 62.26 +/- 1.93 to 70.50 +/- 0.87, respectively. Significant differences in top and bottom KHN values were observed between different curing regimens for the same light, and between LED and halogen lights. Although curing with most modes of EL resulted in significantly lower top and bottom KHN values than the control, no significant difference was observed for the different modes of FL. Hence, the effectiveness of composite cure with LED LCUs is product dependent.     

Effectiveness of composite cure with pulse activation and soft-start polymerization

The study investigated the effectiveness of composite cure with pulse activation and soft-start polymerization. A light-cure unit (BISCO VIP, BISCO Dental Products, Schaumburg, IL 60193, USA) that allowed for independent command over time and intensity was used. The six light-curing modes examined were: Control (C)-400 mW/cm2 [40 seconds]; Pulse Delay I (PDI) -100 mW/cm2 [3 seconds] --> delay [3 minutes] --> 500 mW/cm2 [30 seconds]; Pulse Delay II (PDII) - 200 mW/cm2 [20 seconds] --> delay [3 minutes] --> 500 mW/cm2 [30 seconds]; Soft-start (SS) - 200 mW/cm2 [10 seconds] --> 600 mW/cm2 [30 seconds]; Pulse Cure I (PCI) - 400 mW/cm2 [10 seconds] --> delay [10 seconds] --> 400 mW/cm2 [10 seconds] --> delay [10 seconds] --> 400 mW/cm2 [20 seconds]; and Pulse Cure II (PCII) - 400 mW/cm2 [20 seconds] --> delay [20 seconds] --> 400 mW/cm2 [20 seconds]. Effectiveness of cure with the different modes was determined by measuring the top and bottom surface hardness of 2 mm thick composite (Z100) specimens using a digital microhardness tester (load=500 gf; dwell time=15 seconds). The effectiveness of cure of the bottom surface of the composite was also established by Fourier Transform Infrared (FTIR) spectroscopy using the KBr technique. Data obtained was analyzed using one-way ANOVA/Scheffe's post-hoc test (p<0.05). No significant difference in top Knoops Hardness Number KHN wa s observed except for PDIand PDII. At the bottom surfaces, KHN obtained with the control was significantly greater than with PDII, SS and PCII. FTIR results ranked well with the hardness of the bottom surfaces. The absorbance ratio of carbon double bonds to aromatic ring obtained with the control group was significantly greater than with PDII and PCII. Effectiveness of the cure at the bottom surfaces of composites may be reduced by some pulse activation and soft-start polymerization regimens.     

A Qualitative Exploration of the Views of Policymakers and Policy Advisors on the Impact of Mental Health Stigma on the Development and Implementation of Mental Health Policy in Singapore

Few studies have examined the views of policy makers regarding the impact of mental health stigma on the development and implementation of mental health policies. This study aimed to address this knowledge gap by exploring policymakers’ and policy advisors’ perspectives regarding the impact of mental health stigma on the development and implementation of mental health programmes, strategies, and services in Singapore. In all 13 participants were recruited for the study comprising practicing policymakers, senior staff of organisations involved in implementing the various mental health programmes, and policy advisors. Data was collected through semi-structured interviews, which were transcribed verbatim and analysed using reflexive thematic analysis. Data analysis revealed three superordinate themes related to challenges experienced by the policymakers/advisors when dealing with mental health policy and implementation of programmes. These themes included stigma as a barrier to mental health treatment, community-level barriers to mental health recovery, and mental health being a neglected need. Policymakers/advisors demonstrated an in-depth and nuanced understanding of the barriers (consequent to stigma) to mental healthcare delivery and access. Policymakers/advisors were able to associate the themes related to the stigma towards mental illness with help-seeking barriers based on personal experiences, knowledge, and insight gained through the implementation of mental health programmes and initiatives.

     

Mental disorders: employment and work productivity in Singapore

Aim

To examine the association between mental disorders and work disability in the adult resident population in Singapore.

Method

Data are from the Singapore Mental Health Study, which was a household survey of a nationally representative sample. The main instrument used was the Composite International Diagnostic Interview (CIDI). Employment-related information was collected using the modified employment module of the CIDI.

Results

A total of 6,429 respondents were included in the analysis, 71 % (n = 4,594) were employed, 24.5 % (n = 1,522) were economically inactive and 4.5 % (n = 313) were unemployed. Among the employed, 2.3 % had a 12-month prevalence of at least one mental disorder, while 5.3 % of the unemployed had at least one mental disorder. The average number of work loss days (absenteeism) per capita among those with a mental disorder was 0.5 per month that is equivalent to an annualized national projection of approximately 0.3 million productivity days. The average work-cutback days (presenteeism) were 0.4 days among this group. Of the mentally ill in the workforce, a high proportion (86.5 %) did not ever seek help for problems related to mental health.

Conclusion

Our findings provide information on the significant consequences of mental disorders on the workforce in terms of lost work productivity, which could pave the way for a more rational allocation of scarce resources.     

Assessing quality of a worksite health promotion programme from participants’ views: findings from a qualitative study in Malaysia

Background An assessment of the process and outcomes of a health promotion programme is necessary for the continuous improvement of a programme. Objective To explore the participants’ perceptions of the quality and effectiveness of the ‘Love Your Heart Programme’. Design A qualitative study using semi‐structured interviews with a purposive sample of participants of the ‘Love Your Heart’ programme. Interviews were based on an interview guide that grouped questions into four main subgroups: structure, process, immediate outcomes and impact. The interviews were audio‐recorded, transcribed verbatim and analysed using the principles of grounded theory. Results A total of 17 interviews were conducted. The participants were satisfied with the structural aspects of the programme. Different opinions arose regarding the ideal frequency and duration of the programme. The content of the seminars was thought to be too general. There was also a lack of interest in the ‘Road to a Healthy Heart’ booklet. All of the respondents had positive opinions about the communication skills and attitude of the health educator. The potential advantages and disadvantages of participating in the programme were discussed. Finally, the respondents expressed their satisfaction with the programme and the impact it had on them. Discussion and conclusions In general, the participants who were interviewed held the programme, and the health educator conducted the programme in high regard. The suggestions that were received can be used to further improve the acceptability and feasibility of the programme.     

From well-being to positive mental health: conceptualization and qualitative development of an instrument in Singapore

Purpose

There is no global definition of well-being. Cultural differences in the perception of well-being and the social and behavioral contexts further limit its measurement. Existing instruments are developed in Western societies that differ in their conceptualization of well-being from Asian populations. Moreover, very few instruments address the multidimensional construct of well-being.

Methods

Literature was reviewed to develop a priori conceptual framework of mental health and well-being. Concepts were identified based on specific criteria to guide the qualitative investigations. Finally, focus group discussions were conducted among adults belonging to the three major ethnicities in Singapore to identify salient domains of mental health and well-being.

Results

Mental well-being is a multidimensional construct constituting of positive affect, satisfaction, and psychological functioning. While well-being explains the functional and psychological components, positive mental health is a combination of these and the skills required to achieve them. Although there is an overlap between the concepts identified from the literature and those identified in Singapore, certain differences existed, particularly with the relevance attributed to family interactions and religiosity or spirituality. Similar findings were observed across the three ethnic groups.

Conclusion

Domains identified can be used to develop a culturally relevant instrument in Singapore.     

Microstructural models for diffusion MRI in breast cancer and surrounding stroma: an ex vivo study

The diffusion signal in breast tissue has primarily been modelled using apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM) and diffusion tensor (DT) models, which may be too simplistic to describe the underlying tissue microstructure. Formalin‐fixed breast cancer samples were scanned using a wide range of gradient strengths, durations, separations and orientations. A variety of one‐ and two‐compartment models were tested to determine which best described the data. Models with restricted diffusion components and anisotropy were selected in most cancerous regions and there were no regions in which conventional ADC or DT models were selected. Maps of ADC generally related to cellularity on histology, but maps of parameters from more complex models suggest that both overall cell volume fraction and individual cell size can contribute to the diffusion signal, affecting the specificity of ADC to the tissue microstructure. The areas of coherence in diffusion anisotropy images were small, approximately 1 mm, but the orientation corresponded to stromal orientation patterns on histology.