Randomized in situ evaluation of surface polishing protocols on the caries-protective effect of resin Infiltrant.

The aim of this placebo-controlled randomized in situ study was to evaluate the effect of different surface polishing protocols on enamel roughness, bacterial adhesion and caries-protective effect of a resin infiltrant. Seventy-five bovine enamel samples having artificial caries lesions were treated with a resinous infiltrant and afterwards randomly dividided into five polishing protocols: aluminum oxide flexible disks (Al2O3-Disks), silicon carbide tips (SIC-Tips), silicon carbide brush (SIC-Brush), silicon carbide polyester strips (SIC-Strips) or no polishing [negative control (NC)]. Average surface roughness (Ra) was assessed by profilometry. Samples were mounted in palatal appliances under a mesh for biofilm accumulation. Fifteen volunteers wore the intraoral appliances (14-days) and cariogenic challenge was triggered by sucrose solutions. Biofilm formed was collected for microbiological analysis of caries-related bacteria (Streptococcus mutans, Lactobacillus acidophilus) and demineralization was assessed by cross-sectional microhardness. Mean Knoop hardness numbers (Kg/mm2) were plotted over lesion depth (µm) and area under the lesion curve was subtracted from sound enamel to determine demineralization (ΔS, Kg/mm2xµm). Data were analyzed by ANOVA and post-hoc comparisons (α = 0.05). NC resulted in significantly higher Ra means than Al2O3-Disks and SIC-Strips. Bacterial counts were not significantly different between the groups (p > 0.05). Regards ΔS means, however none of the groups were significantly different to NC (6983.3 kg/mm2xµm /CI 4246.1-9720.5, p > 0.05). Conclusions: Polishing protocols (Al2O3-Disks, SIC-Strips) significantly decreseased roughness of infiltrated-enamel, however none of the polishing protocols could signicantly decrease bacterial counts nor resulted in significant less demineralization

Applying the ALARA concept to the evaluation of vesicoureteric reflux

The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux

Fluvial Incisions in the North-Western Pyrenees (Aspe Valley, France): Dissection of a Former Planation Surface and Some Tectonic Implications

International audienceThe Pyrenean range results from the collision between the Iberian and Eurasian plates which started during the Santonian. Iberia has shown no more relevant motion with respect to Europe since Early Miocene times. In this regard, the Pyrenees can no longer be considered as an active plate boundary from Miocene onwards. Dissected remnants of a high elevation low relief surface (HELRS) are encountered all along the Pyrenean range. All authors agree on the tardi- to post-shortening age of this surface, but doubt remains on its original elevation. In particular, whether a substantial post-shortening uplift occurred after the generation of the Pyrenean planation surface is still debated.Based on a geomorphological study of the entrenchment of the Aspe River in the North-Western Pyrenees, we evidence a Lower Miocene to present-day multi-stage history of dissection of the HELRS in the North-Western Pyrenees. Each incision stage is recorded by erosional triangular facets and associated stepped remnants of palaeovalleys. Compared analysis of the patterns of incisions characterizing (i) the Axial Zone of the range and (ii) its northern border allows to evidence differential vertical motion. We finally discuss the process(es) controlling the deduced uplift of the Western Pyrenean Axial Zone