Tooth-whitening activity of a novel home-bleaching system utilising thermal diffusion : a multifactorial simultaneous evaluation of efficacy at cervical, body and incisal tooth sites

Introduction The ability of a thermal diffusion system (TDS) to promote the tooth-whitening actions of a bleaching gel/bleaching activator combination product (containing a final hydrogen peroxide (H2O2) content of 10.0% (w/v)) towards discoloured 'smile-zone' teeth was examined. Methods Fifty teeth in 15 participants aged 18-62 years were investigated. The CIE tooth shade parameters L*, a* and b*, together with Vitapan shade scores (VSSs), were simultaneously recorded at three separate tooth areas (cervical, body and incisal sites) with a novel spectrophotometric monitoring system before treatment, and also at 14 days after completion of a 10-day treatment period in which the product was applied 'at-home' (twice daily). Results The tooth-whitening treatment administered gave rise to extremely significant increases in L*, and decreases in the a* and b* shade parameters for each of the tooth areas investigated (p <10−10). Post-treatment mean decreases in the VSS values were 8.26, 9.70 and 9.14 for the cervical, body and incisal areas respectively (p <10−8 in each case). Mean ΔE values determined post-treatment were also very highly significant for each tooth region examined (p <10−10 in each case). Conclusions The tooth-whitening system tested exerted extremely powerful bleaching actions in all tooth areas investigated. The order of tooth-whitening effectiveness was body > incisal > cervical for Δb* and ΔE, and incisal > body > cervical for Δa* and ΔL*, and this may reflect the TDS's ability to promote the penetration of H2O2 to intrinsic stain sites

The roles of a university professor in a teacher study group

[[abstract]]The opportunities in which university professors collaborate with the practicing school teachers in a teacher study group are few. This study investigated how a university professor facilitated a collaborative teacher study group to enhance teachers’ professional growth. Five primary school teachers and a university professor collaborated on incorporating Reader’s Theatre into the design and revision of the curriculum in a teacher study group. This study not only identified the roles of the university professor but also highlighted how this outside stimulus facilitated the process of teachers’ professional dialogues in this teacher study group. Five roles of the professor in the teacher study group were identified, including content expert, information provider, thought challenger, discussion facilitator, and caring listener. The discrepancies toward the roles that the professor in the teacher study group should serve between the elementary school teachers and the university professor were analyzed and reported. Implications were drawn for both classroom teachers and university professors