Case reports in pediatric dentistry

Abstract

REVIEWSpreparation, disinfection and obturation. These chapters explain the nature of the problem facing the clinician, how to prevent complications, and their management in the event of occurrence.Also covered are key areas such as perforations, root and instrument fractures and re-treatments. The book imbibes the reader with essential information on the materials and techniques required, whilst again guided by excellent clinical photography and key points.In conclusion, this book is a must for any dental centre or specialist's library. Each chapter condenses the information into easily digested segments and key points. The text is expertly illustrated throughout with fi rst class clinical photography and clever illustrations. A particular highlight is the way scientifi c fi ndings have been incorporated and referenced throughout the text, thus bringing evidence based learning to life. As a result, this book could be strongly recommended to any dentist performing endodontic treatment.

Passivity and Pit Stability Behavior of Copper as a Function of Selected Water Chemistry Variables

“…Passivity.-Effect of OH Ϫ -borate buffer solutions.-Borate buffer solutions were used to study the effect of OH − on passivation independent of SO 4 2− , Cl − , and HCO 3 − /CO 3 2− concentration. CVS tests were repeated on 250 m diameter copper wires in borate buffer solutions from pH 5-11.…”

“…Environment.-The following electrolytes were used to examine passivity and pitting: borate buffer solutions, HCO 3 − , one specific synthetic water recipe called Edwards synthetic water, 64 4 2− in pH 8.3 and 9.5 waters. Edwards synthetic water simulated the ionic constituents found at a water utility whose consumers experienced pitting problems.…”

“…35 OH − , HCO 3 − , SO 4 2− , and Cl − are four important inorganic anions related to passivity and pitting in potable water. 38,41,46 In contrast, SO 4 2− only causes active pitting and may be a more potent anion than Cl − . HCO 3 − is generally considered as a beneficial anion to copper pipes in promoting passivity and inhibiting localized breakdown by aggressive anions.…”

“…The effect of each anion on the stability of the passive film on copper has been widely studied in different environments. 38,41,55 Furthermore, combinations of aggressive anions and inhibiting anions ͓͑SO 4 2− ͔/͓HCO 3 − ͔, 7,9,55,56 ͓Cl − ͔/͓HCO 3 − ͔, 42 and ͓SO 4 2− ͔/͓OH − ͔ 57 ͒ have also been a subject of some studies, and some critical anion ratios have been specified to minimize the pitting problems. 9,36 The mechanism is due to either the buffering capability which prevents local acidity or the formation of a possibly protective basic copper carbonate film, CuCO 3 ͑cupric carbonate͒, Cu͑OH͒ 2 ·CuCO 3 ͑mala-chite͒, Cu͑OH͒ 2 ·2CuCO 3 ͑azurite͒, or any combination of these minerals.…”

“…Although considerable research has been devoted to either the thermodynamic stability of copper or practical exposures in a variety of systems, e.g., Cu-Cl − -H 2 O, Cu-SO 4 2− -H 2 O, and Cu-H 2 CO 3 -H 2 O, 10,58 less attention has been paid to the governing electrochemical aspects of copper associated with pitting in different systems. Selected waters that cause cold water pitting of copper are known, 2,3,5,6,13,35 but the specific electrochemical factors governing pit initiation and propagation as a function of water-chemistry vari-ables are unclear.…”