Attending and avoiding dental appointments: Do "bright" and "dark" motivational paths have a role?

OBJECTIVE: The aim of this study was to test a self-determination theory (SDT) process model of the "bright" and the "dark" motivational pathways through dental attendance or avoidance to oral health. METHODS: A cross-sectional study was conducted among 322 students from all study disciplines at the University of Oslo. Participants responded to a survey with validated questionnaires. Structural equation modelling was used to test the SDT model, and a bootstrapping procedure was used to test the indirect links in the model. RESULTS: Along the "bright" path: Autonomy support at the dental clinic was positively associated with need satisfaction in treatment, which was positively associated with autonomous motivation for dental treatment and reappraisal of dental anxiety. Further, autonomous motivation was positively related to dental attendance, which in turn predicted oral health. Also, both autonomous motivation and reappraisal of anxiety were negatively related to avoiding dental appointments. Along the "dark" path: Conditional regard at the dental clinic positively predicted need frustration in treatment, which positively predicted dental anxiety. In turn, dental anxiety positively predicted avoiding appointments, along with the negative predictions by autonomy and anxiety reappraisal. Finally, oral health was negatively predicted by avoiding appointments. A bootstrapping procedure indicated that all indirect links in the model were supported. A SEM fit the data very well. CONCLUSIONS: Because of the high level of explained variances for dental attendance (42%) and avoiding dental appointments (52%), promoting autonomy support and avoiding conditional regard at the dental clinic may be important for patients' oral health.

Relationships between tissue composition and viscoelastic properties in human trabecular bone.

Trabecular bone is a metabolically active tissue with a high surface to volume ratio. It exhibits viscoelastic properties that may change during aging. Changes in bone properties due to altered metabolism are sensitively revealed in trabecular bone. However, the relationships between material composition and viscoelastic properties of bone, and their changes during aging have not yet been elucidated. In this study, trabecular bone samples from the femoral neck of male cadavers (n=21) aged 17-82 years were collected and the tissue level composition and its associations with the tissue viscoelastic properties were evaluated by using Raman microspectroscopy and nanoindentation, respectively. For composition, collagen content, mineralization, carbonate substitution and mineral crystallinity were evaluated. The calculated mechanical properties included reduced modulus (Er), hardness (H) and the creep parameters (E1, E2, η1and η2), as obtained by fitting the experimental data to the Burgers model. The results indicated that the creep parameters, E1, E2, η1and η2, were linearly correlated with mineral crystallinity (r=0.769-0.924, p<0.001). Creep time constant (η2/E2) tended to increase with crystallinity (r=0.422, p=0.057). With age, the mineralization decreased (r=-0.587, p=0.005) while the carbonate substitution increased (r=0.728, p<0.001). Age showed no significant associations with nanoindentation parameters. The present findings suggest that, at the tissue-level, the viscoelastic properties of trabecular bone are related to the changes in characteristics of bone mineral. This association may be independent of human age.