In situ effect of CO2 laser (9.3 μm) irradiation, combined with AmF/NaF/SnCl2 solution in prevention and control of erosive tooth wear in human enamel

OBJECTIVES

This single-blind, controlled cross-over in situ study aimed to evaluate the effect of CO2 laser (9.3µm) irradiation, combined with AmF/NaF/SnCl2 solution on prevention and control of Erosive Tooth Wear (ETW) in human enamel.

MATERIALS AND METHODS

Two trial conditions were analyzed, Condition-1 as ETW-prevention (sound tooth surface) and Condition-2 as ETW-control (in vitro initial erosive lesion). The experiment was conducted in two phases, one with one without exposure to AmF/NaF/SnCl2 solution. A hundred and ninety-two samples of human enamel (3x3x1mm) were randomly divided into 4 experimental groups for each condition: (C) without treatment (negative control); (F) AmF/NaF/SnCl2 solution (positive control); (L) CO2 laser irradiation; (L+F) CO2 laser+AmF/NaF/SnCl2 solution. Twelve volunteers used a removable device each containing 8 samples per phase. Ex-vivo erosive challenges (4×5min/day) and rinsing protocol (1×30s/day) were performed. The surface loss was determined using optical profilometer (n=12 per group), and the surface morphology was observed with Scanning Electron Microscopy (n=3).

RESULTS

Condition-1 data were analyzed by one-way ANOVA and Condition-2 by two-way repeated measures ANOVA, both with Tukey post-hoc tests (α=5%). Condition-1: groups L (4.59 ±2.95µm) and L+F (1.58 ±1.24µm) showed significantly less surface loss in preventing ETW than groups C and F. Condition-2: in controlling the progression of ETW, L+F was the only group with no significant surface loss between initial erosive lesion (3.65 ±0.16µm) and after erosive challenge (4.99 ±1.17µm).

CONCLUSIONS

CO2 9.3µm laser application prevented and controlled ETW progression in human enamel, with greater efficiency when combined with AmF/NaF/SnCl2 solution application.

The effect of CO2 9.3 μm short-pulsed laser irradiation in enamel erosion reduction with and without fluoride applications-a randomized, controlled in vitro study

The aim of this in vitro study was to evaluate the protective effect of short-pulsed CO₂ 9.3 μm laser irradiation against erosion in human enamel without and combined with TiF₄ and AmF/NaF/SnCl₂ applications, respectively, as well as compared to the protective effect of these fluoride treatments alone. After polishing, ninety enamel samples (3 × 3mm) were used for 9 different treatment groups: 4% TiF₄ gel (pH 1.5, 24,533 ppm F^-); AmF/NaF/SnCl₂ rinse (pH 4.5; 500 ppm F^-, 800 ppm Sn²); CO₂ laser (average power 0.58 W); CO₂ laser (0.58 W) + TiF₄; CO₂ laser (0.58 W) + AmF/NaF/SnCl₂; CO₂ laser (0.69 W); CO₂ laser (0.69 W) + TiF₄; CO₂ laser (0.69 W) + AmF/NaF/SnCl₂; negative control (deionized water). TiF₄ gel was brushed on only once before the first erosive cycling, while samples treated with AmF/NaF/SnCl₂ were daily immersed in 5 ml of the solution before cycling. Laser treatment occurred with a CO₂ laser (wavelength 9.3 μm, pulse repetition rate 100 Hz, pulse duration 14.6 μs/18 μs, average power 0.58 W/0.69 W, fluence 1.9 J/cm²/2.2 J/cm², beam diameter 0.63 mm, irradiation time 10 s, air cooling). TiF₄ was applied only once, while AmF/NaF/SnCl₂ was applied once daily before the erosive challenge. Surface loss (in μm) was measured with optical profilometry immediately after treatment, and after 5 and 10 days of erosive cycling (0.5% citric acid, pH 2.3, 6 × 2 min/day). Additionally, scanning electron microscopy investigations were performed. All application measures resulted in loss of surface height immediately after treatment. After 5 days, significantly reduced surface loss was observed after applying laser irradiation (both power settings) followed by applications of TiF₄ or AmF/NaF/SnCl₂ solution (p < 0.05; 2-way ANOVA and Tukey test) compared to fluoride application alone. After 10 days, compared to after 5 days, a reduced tissue loss was observed in all groups treated with AmF/NaF/SnCl₂ solution. This tissue gain occurred with the AmF/NaF/SnCl₂ application alone and was significantly higher when the application was combined with the laser use (p < 0.05). Short-pulsed CO₂ 9.3 μm laser irradiation followed by additional application of AmF/NaF/SnCl₂ solution significantly reduces the progression of dental enamel erosion in vitro.

Alcohol consumption and hangover patterns among migraine sufferers

Aims:

Alcohol hangover is a poorly understood cluster of symptoms occurring following a heavy consumption of alcohol. The term “delayed alcohol-induced headache” is often used synonymously. Our objective was to compare alcohol hangover symptoms in migraine sufferers and nonsufferers.

Materials and Methods:

In this cross-sectional study, university students were asked to fill structured questionnaires assessing headache history, alcoholic consumption, and hangover symptoms (using the Hangover Symptom Scale (HSS)). Subjects were classified as suffering from migraine with or without aura and nonsufferers according the International Classification of Headache Disorders 2^nd Edition (ICHD-II). The 13 hangover symptoms were divided by the researches into migraine-like and other nonmigraine-like symptoms.

Results:

Hangover symptoms among 95 migraine sufferers and 597 nonsufferers were compared. Migraine sufferers consumed less alcohol compared with the nonsufferers (mean drinks/week 2.34 ± 4.11 vs. 2.92 ± 3.58, P = 0.038) and suffered from higher tendency to migraine-like symptoms after drinking (mean 2.91 ± 3.43 vs. 1.85 ± 2.35, P = 0.002) but not to other hangover symptoms (mean 5.39 ± 6.31 vs. 4.34 ± 4.56, P = 0.1).

Conclusions:

Migraine sufferers consume less alcohol, especially beer and liquors, and are more vulnerable to migraine-like hangover symptoms than nonsufferers. The finding that the tendency to develop migraine attacks affects the hangover symptomatology may suggest a similarity in pathophysiology, and possibly in treatment options.

Just say know: an examination of substance use disorders among older adults in gerontological and substance abuse journals

This article examines the extent to which studies of alcohol abuse, illicit drug use, and prescription drug abuse among older adults appear in the leading gerontological and substance abuse journals. The authors reviewed articles published in the 10 social science gerontological journals and the 10 social science substance abuse journals with the highest 5-year impact factors in PubMed from 2000 to 2010. Articles were selected that presented original research on alcohol, substance, or prescription abuse with older adults aged 50 and older; and were identified through aging and substance abuse-related Medical Subject Headings and word searches of titles and abstracts (N = 634). Full text of each article was reviewed by the authors, and consensus determined inclusion in the final sample. Of the 19,953 articles published respectively in the top 10 gerontological and substance abuse journals, 181 articles met the inclusion criteria of reporting findings related to substance use disorders among older adults. Specifically, 0.9% (102 of 11,700) of articles from the top 10 gerontology journals and 1.0% (79 of 8,253) of articles from the top 10 substance abuse journals met the criteria. Most published articles addressed alcohol misuse/abuse or polysubstance abuse with few articles addressing illicit drug use or the misuse of prescription medications. Less than 1% of articles published in the 10 gerontology journals and the 10 substance abuse journals with the highest 5-year impact scores addressed substance abuse in older adults. Practitioners treating health and/or mental health problems are at a disadvantage in accurately identifying and treating these conditions in older adult populations without a proper understanding of the role of comorbid substance use disorders.

Multiattribute Auctions Based on Generalized Additive Independence

We develop multiattribute auctions that accommodate generalized additive independent (GAI) preferences. We propose an iterative auction mechanism that maintains prices on potentially overlapping GAI clusters of attributes, thus decreases elicitation and computational burden, and creates an open competition among suppliers over a multidimensional domain. Most significantly, the auction is guaranteed to achieve surplus which approximates optimal welfare up to a small additive factor, under reasonable equilibrium strategies of traders. The main departure of GAI auctions from previous literature is to accommodate non-additive trader preferences, hence allowing traders to condition their evaluation of specific attributes on the value of other attributes. At the same time, the GAI structure supports a compact representation of prices, enabling a tractable auction process. We perform a simulation study, demonstrating and quantifying the significant efficiency advantage of more expressive preference modeling. We draw random GAI-structured utility functions with various internal structures, generate additive functions that approximate the GAI utility, and compare the performance of the auctions using the two representations. We find that allowing traders to express existing dependencies among attributes improves the economic efficiency of multiattribute auctions.

CUI Networks: A Graphical Representation for Conditional Utility Independence

We introduce CUI networks, a compact graphical representation of utility functions over multiple attributes. CUI networks model multiattribute utility functions using the well-studied and widely applicable utility independence concept. We show how conditional utility independence leads to an effective functional decomposition that can be exhibited graphically, and how local, compact data at the graph nodes can be used to calculate joint utility. We discuss aspects of elicitation, network construction, and optimization, and contrast our new representation with previous graphical preference modeling.

Impending Volkmann's contracture in a newborn

A newborn presented with severe necrosis of the volar aspect of the forearm and impending Volkmann's contracture. This is the youngest such patient reported in the literature. We suspect prolonged intrauterine pressure from an amniotic band. Such bands are known to cause constricting rings, syndactyly, and congenital amputations. If our assumption is correct, this case is unique.