High phosphate content significantly increases apatite formation of fluoride-containing bioactive glasses

NOTICE: this is the author’s version of a work that was accepted for publication in Acta Biomaterialia. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Acta Biomaterialia, [VOL 7, ISSUE 4, (2001)] DOI: 10.1016/j.actbio.2010.11.03

Decreased startle modulation during anticipation in the postpartum period in comparison to late pregnancy

Knowledge about healthy women’s psychophysiological adaptations during the large neuroendocrine changes of pregnancy and childbirth is essential in order to understand why these events have the potential to disrupt mental health in vulnerable individuals. This study aimed to compare startle response modulation, an objective psychophysiological measure demonstrated to be influenced by anxiety and depression, longitudinally across late pregnancy and the postpartum period. The acoustic startle response modulation was assessed during anticipation of affective images and during image viewing in 31 healthy women during gestational weeks 36–39 and again at 4 to 6 weeks postpartum. No startle modulation by affective images was observed at either time point. Significant modulation during anticipation stimuli was found at pregnancy assessment but was reduced in the postpartum period. The women rated the unpleasant images more negative and more arousing and the pleasant images more positive at the postpartum assessment. Self-reported anxiety and depressive symptoms did not change between assessments. The observed postpartum decrease in modulation of startle by anticipation suggests a relatively deactivated defense system in the postpartum period

Mood Modulates Auditory Laterality of Hemodynamic Mismatch Responses during Dichotic Listening

Hemodynamic mismatch responses can be elicited by deviant stimuli in a sequence of standard stimuli even during cognitive demanding tasks. Emotional context is known to modulate lateralized processing. Right-hemispheric negative emotion processing may bias attention to the right and enhance processing of right-ear stimuli. The present study examined the influence of induced mood on lateralized pre-attentive auditory processing of dichotic stimuli using functional magnetic resonance imaging (fMRI). Faces expressing emotions (sad/happy/neutral) were presented in a blocked design while a dichotic oddball sequence with consonant-vowel (CV) syllables in an event-related design was simultaneously administered. Twenty healthy participants were instructed to feel the emotion perceived on the images and to ignore the syllables. Deviant sounds reliably activated bilateral auditory cortices and confirmed attention effects by modulation of visual activity. Sad mood induction activated visual, limbic and right prefrontal areas. A lateralization effect of emotion-attention interaction was reflected in a stronger response to right-ear deviants in the right auditory cortex during sad mood. This imbalance of resources may be a neurophysiological correlate of laterality in sad mood and depression. Conceivably, the compensatory right-hemispheric enhancement of resources elicits increased ipsilateral processing

Comparison of Cervical and Mid Coronal Dentine Using a Desensitizing Bioactive Glass Toothpaste: A Pilot Study

Aim: The aim of the present studywas to compare the effect of a calcium sodium phosphosilicate (NovaMin®) desensitizing agent (a bioactive glass) on both cervical and mid coronal dentine sections using scanning electron microscopy (SEM). Methods: Sections of both cervical and mid coronal dentine were prepared and etched with 5% citric acid for 5 minutes; these sections were then brushed with 2mg of Sensodyne Repair and Protect (NovaMin®) for 2 minutes with a powered toothbrush (Oral B, Braun) and left in artificial saliva (AS) for an hour at 37o degrees. One group, a control, was brushed only with distilled water and another group was subjected to a one-minute acid challenge with 5% citric acid. Samples were then prepared for anaylsis with SEM. Results: The dentinal tubules identified on the root surface were narrower and less numerous compared to a mid-coronal section. In the test group, there was evidence of bioglass occlusion in 100% of the tubules after treatment.After the acid challenge approximately 6% of tubules were not occluded at all and 42% were only partially occluded with less than 50% of the diameter of the tubule closed. Conclusions: The bioactive glass toothpaste (NovaMin®) appeared to occlude all of the dentinal tubules by more than 50% of their diameter and partially resisted an acid challenge on the cervical dentine section. The use of a cervical dentine section appeared comparable to the images of mid coronal dentine and would be more relevant for the evaluation of potential desensitizing products in the treatment of Dentine hypersensitivity. The sectioning of cervical dentine however may be more challenging than the sectioning of mid coronal dentine