Nanoclay addition to a conventional glass ionomer cements: Influence on physical properties
Objective: The objective of the present study is to investigate the reinforcement effect of  polymer-grade montmorillonite (PGN nanoclay) on physical properties of glass ionomer cement (GIC). Materials and Methods: The PGN nanoclay was dispersed in the liquid portion of GIC (HiFi, Advanced Healthcare, Kent, UK) at 1%, 2% and 4% (w/w). Fourier-transform infrared (FTIR) spectroscopy was used to quantify the polymer liquid of GICs after dispersion of nanoclay. The molecular weight (M w ) of HiFi liquid was determined by gel permeation chromatography. The compressive strength (CS), diametral-tensile strength, flexural strength (FS) and flexural modulus (E f ) of cements (n = 20) were measured after storage for 1 day, 1 week and 1 month. Fractured surface was analyzed by scanning electron microscopy. The working and setting time (WT and ST) of cements was measured by a modified Wilson′s rheometer. Results: The FTIR results showed a new peak at 1041 cm−1 which increased in intensity with an increase in the nanoclay content and was related to the Si-O stretching mode in PGN nanoclay. The M w of poly (acrylic acid) used to form cement was in the range of 53,000 g/mol. The nanoclay reinforced GICs containing <2% nanoclays exhibited higher CS and FS. The E f cement with 1% nanoclays was significantly higher. The WT and ST of 1% nanoclay reinforced cement were similar to the control cement but were reduced with 2% and 4% nanoclay addition. Conclusion: The dispersion of nanoclays in GICs was achieved, and GIC containing 2 wt% nanoclay is a promising restorative materials with improved physical properties.
Glass-ionomer cements in restorative dentistry.
This article reviews the current status and future prospects for glass-ionomer materials. These materials are of two chemical types: the older, self-hardening cements, which set by an acid-base neutralization reaction to give relatively brittle materials; and the newer, resin-modified cements, which set partly by polymerization and partly by neutralization. Compared with the self-hardening cements, the latter materials have improved esthetics, improved resistance to moisture, and greater toughness. Both types of glass-ionomer cement bond well to enamel and dentin and release a clinically useful amount of fluoride. They have been used in a variety of applications: as liners or bases, for luting of stainless steel crowns, for Class V restorations in permanent teeth, and for Class II and Class III restorations in primary teeth. The resin-modified glass-ionomers are particularly promising for these latter uses, although it is too early to be sure whether their long-term durability is sufficient. Self-hardening glass-ionomer materials are likely to retain specific niches of clinical application, including in their metal-reinforced and cermet-containing forms.
PACU nurses & postoperative pain : A focused ethnography
....................... ...... .......................... ...... ............... VII I CHAPTER 1: INTRODUCTION ....................... .. .... .. .................... .. .. . 1 1.1 CONTEXT AND SIGNIFICANCE OF THE STUDY .................................................... 1 1.2 STATEMENT OF THE RESEARCH PROBLEM ........................................................ 2 1.3 PURPOSE OF THE STUDY ............................................................................... 3 1.3.1 Aim .................................................................................................................................... 3 1.3.2 Objectives .................................................................................................................... 3 1.4 STATEMENT OF THE RESEARCH QUESTION ....................................................... 4 1.5 ASSUMPTIONS ............................................................................................ 4 1.6 DEFINITIONS OF TERMS ................................................................................ 4 1.7 SUMMARY OF THE THESIS ............................................................................. 6 CHAPTER 2: LITERATURE REVIEW ........................ ...... .................. 8 2.1 INTRODUCTION ........................................................................................... 8 2.2 SEARCH STRATEGY ..................................................................................... 8 2.3 PAIN: AN OVERVIEW ................................................................................... 9 2.3.1 Defining Pain .............................................................................................................. 9 2.3.2 The Physiology of Acute Pain .................................................................... 12 2.3.3 Summary of the Pain Experience ............................................................. 14 2.4 SITUATING THE POST-ANAESTHETIC CARE UNIT ............................................. 16 2.4.1 A Brief History ....................................................................................................... 16 2.4.2 Postoperative Pain in the PACU ................................................................ 17 2.4.3 Challenges for the PACU Nurse ................................................................. 19 2.5 ASSESSING AND MANAGING POSTOPERATIVE PAIN .......................................... 20 2.5.1 Nurses’ Experiences, Perceptions and Strategies ....................... 21 2.5.2 The Complexity of Postoperative Pain Assessment and Management ............................................................................................................................... 24 2.6 ETHNOGRAPHY ......................................................................................... 26 2.6.1 An Introduction to Ethnography .............................................................. 26 2.6.2 Ethnography in Nursing Practice .............................................................. 26 2.6 SUMMARY ................................................................................................ 28