ABSTRACT
Studies have shown how generativity, the concern for establishing and guiding the next generation and safeguarding its wellbeing, functions as an intergenerational conduit, bridging the developmental stages of older individuals with those younger. Yet, applications of generativity, as a means to bridge generational gaps within rapid social change, remain underexplored in the intergenerational field. Using Singapore as a case study, and through focus group discussions with 103 older persons, this paper examines how older Singaporeans express their generative concern and internalize their generative capacities across different social settings and rapid socioeconomic transformation. Mismatch between older Singaporeans' generative concern and capacity contributes to ambivalence - mixed feelings about guiding younger generations - which emerges out of older Singaporeans' struggles with cultural change prompted by economic progress, as well as concerns about their place and value in a technologically advanced global city-state. The concept of generative ambivalence can add value to policy perspectives on intergenerational cohesion, as it considers people's attempts to forge commonalities and mutual reciprocity despite differences (e.g. gender, age, race, skills), as well as highlights intergenerational complexities beyond superficial binaries. Policies aimed at bringing generations together must be intentional in creating opportunity structures that go beyond categorical differences, where multiple generations can thrive interdependently.
ABSTRACT
AIM: To compare the initial and fatigue shear bond strengths of a chromatic adhesive with a light-cured adhesive in an ex vivo laboratory study. METHODS: Hydroxyapatite discs were used as the bonding substrate. They were produced by cold uni-axial compression at 20 tons, sintered at 1300 degrees C and embedded in epoxy resin before grinding and polishing. One hundred and fifty upper left central incisor brackets were bonded to the discs with Transbond PLUS Color Change (3M Unitek, Monrovia, CA, USA) while another 150 similar brackets were bonded with Transbond XT (3M Unitek, Monrovia, CA, USA). Seventy-five brackets from each group were subjected to cyclic loading (5000 cycles at 2 Hz) at 50 per cent of the mean bond strength in a Dartec Series HC 10 Testing Machine. Initial (unfatigued) and fatigued bond strengths were determined by applying a shear force at the bracket-substrate interface using a custom-made metal jig in an Instron Universal Testing Machine. One-way ANOVA with Bonferroni post-hoc correction and two-way ANOVA were used to analyse the differences between the initial and fatigue mean shear bond strengths of the adhesives. The survival and bond reliability of both adhesives were evaluated with the Kaplan-Meier and Cox regression analyses. RESULTS: The initial mean shear bond strength for Transbond PLUS Color Change (16.72 MPa) was higher than Transbond XT (15.11 MPa), but this was not statistically significant (p = 0.109). The fatigue mean shear bond strength for Transbond XT (15.87 MPa) was similar to that of Transbond PLUS Color Change (15.33 MPa), and the difference was not statistically significant (p > 0.999). There were no significant differences when the effects of the material (p = 0.264) or fatiguing (p = 0.512) were considered separately, but in combination, the effect on bond strength was statistically significant (p = 0.026). The survival analysis showed that both adhesives demonstrated similar survival patterns in the unfatigued and fatigued states. Analysis of the material type and fatiguing showed no effect on the survival pattern for both adhesives (p = 0.098). CONCLUSIONS: There were no statistically significant differences between the mean initial (unfatigued) and fatigue bond strengths of Transbond XT and Transbond PLUS Color Change under laboratory conditions. A survival analysis for both resins with and without fatigue loading exhibited similar behaviour with respect to their survival patterns. Although this may imply that under clinical conditions the two adhesives could behave similarly, the clinical extrapolation of these results should be interpreted with caution.
