Role of Calcium Hydroxide in Dentistry: A Review

2020 ◽  
Vol 12 (02) ◽  
Keyword(s):  
Calcium Hydroxide

The Role of Sodium Hydroxide in the System C3A-CaSO4-H2O at 30°C

1986 ◽  
Vol 85 ◽  
Author(s):  
Hanaa Youssef Ghorab ◽  
Safaa Hussein Abou El Fetouh
Keyword(s):  
Solid Solution ◽  
Sodium Hydroxide ◽  
Calcium Hydroxide ◽  
Hydration Product ◽  
Ion Concentration ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Hydration Reaction ◽  
X Ray Diffraction

ABSTRACTThe hydration reaction of C3A with gypsum (molar ratio = 1:1.5) has been studied in water and in sodium hydroxide solutions at 30°C. The hydration product were analyzed microscopically and by means of X-ray diffraction. The concentration of sulfate and aluminum in solution was determined spectrophotometrically. In the absence of alkali, the amount of ettringite formed passes through a maximum and is accompanied by almost complete consumption of sulphate ion in solution. Alkali depresses the formation of ettringite and accelerates that of calcium hydroxide. The monosulfate hydrate appears immediately in alkaline solutions and water then reappears after a day as a solid solution with the tetracalcium aluminate hydrate. The formation of the monophase solid solution is accompanied by the consumption of C3A, ettringite, and calcium hydroxide and by an increase in the amount of the dissolved aluminum. The presence of alkali markedly increases the initial sulfate ion concentration from solution.

Solvent Replacement Studies of Hydrated Portland Cement Systems: The Role of Calcium Hydroxide

1998 ◽  
Vol 8 (2) ◽  
pp. 56-65 ◽  
Author(s):  
James J Beaudoin ◽  
Ping Gu ◽  
Jacques Marchand ◽  
Basile Tamtsia ◽  
Robert E Myers ◽  
...  
Keyword(s):  
Portland Cement ◽  
Calcium Hydroxide ◽  
Solvent Replacement

scholarly journals In Vivo Study of Calcium Hydroxide Endodontic Treatment in Chronic Apical Periodontitis

2018 ◽  
Vol 24 (4) ◽  
pp. 164-167
Author(s):  
Gheorghiu Irina-Maria ◽  
Mitran Loredana ◽  
M. Mitran ◽  
Temelcea Anca-Nicoleta ◽  
Scarlatesc Sanziana ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Calcium Hydroxide ◽  
Root Canal ◽  
Essential Role ◽  
Apical Periodontitis ◽  
Endodontic Treatment ◽  
Microbial Load ◽  
Root Canals

Abstract The aim of this study was to evaluate the in vivo efficiency of endodontic treatment with calcium hydroxide in chronic apical periodontitis by determining the microbial load from the endodontic space in different stages of treatment. The microbiological determinations that have been made have led to the conclusion that calcium hydroxide possesses a redoubltable antimicrobial activity, but only with the condition of long-lasting contact with the root canals. Another important result is the essential role of the rigorous biomechanical treatment of the root canals, intracanal medication with calcium hydroxide is addresses mostly to microorganisms located in root canal ramifications.

Nonclassical Crystallization of Calcium Hydroxide via Amorphous Precursors and the Role of Additives

2020 ◽  
Vol 20 (7) ◽  
pp. 4418-4432 ◽  
Author(s):  
Carlos Rodriguez-Navarro ◽  
Alejandro Burgos-Cara ◽  
Fulvio Di Lorenzo ◽  
Encarnacion Ruiz-Agudo ◽  
Kerstin Elert
Keyword(s):  
Calcium Hydroxide

scholarly journals Raman Study on Pompeii Potteries: The Role of Calcium Hydroxide on the Surface Treatment

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Daniele Chiriu ◽  
Pier Carlo Ricci ◽  
Andrea Polcaro ◽  
Paolo Braconi ◽  
David Lanzi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Calcium Carbonate ◽  
Surface Treatment ◽  
Calcium Hydroxide ◽  
Archaeological Site ◽  
Ambient Conditions ◽  
Cooking Process ◽  
Raman Study

Pottery samples from the Pompeii archaeological site were investigated by IR Raman spectroscopy and EDAX measurements. The analysis of the Raman spectra of the surfaces reveals the presence calcium hydroxide (peak at about 780 cm−1) while the calcium carbonate is totally absent. The comparative studies on the carbonation effect of the surfaces were performed on laboratory grown samples of calcium hydroxide. The samples were treated at high temperature and exposed to different ambient conditions, and the analysis suggests that the original surfaces of Roman pottery were scattered by calcium hydroxide (limewash) before the cooking process in the furnace. The result of this surface treatment not only permits a vitrification of the surfaces but also seems to reduce the content of CO2in the furnace atmosphere and then obtain a more oxidant ambient during the cooking of the pottery. These results give new insights on the real degree of knowledge of the Romans about the art of ceramics and more generally about chemistry and technologies.

The Role of Silica Fume in the Adhesion of Concrete Restoration Systems

2012 ◽  
Vol 626 ◽  
pp. 265-269 ◽  
Author(s):  
Bassam A. Tayeh ◽  
B.H. Abu Bakar ◽  
M.A. Megat Johari ◽  
A.M. Zeyad
Keyword(s):  
Calcium Hydroxide ◽  
Transition Zone ◽  
Silica Fume ◽  
Adhesion Strength ◽  
Interfacial Transition Zone ◽  
Reactive Powder Concrete ◽  
Ordinary Concrete ◽  
Reactive Powder

The weak interfacial transition zone between new and old concrete is always paid much attention and controls many properties of repaired concrete, The present work reports a study on the influence of the silica fume on the adhesion of reactive powder concrete (RPC), as a concrete restoration material, with the ordinary concrete (OC) substrate. The results showed that, the silica fume presence in the interfacial transition zone significantly enhances the adhesion strength between RPC and OC substrate. Furthermore, the silica fume particles consume calcium hydroxide, which is in attendance in the interfacial transition zone, and make the zone more dense, uniform and tough.

Influence of Several Calcareous Compounds on the Performance of Sulphoaluminate Cement Paste

2014 ◽  
Vol 670-671 ◽  
pp. 407-411
Author(s):  
Yu Tong ◽  
Jun Nan Zhang ◽  
Lin Wang ◽  
Ming Li ◽  
Wei Jian Zhao
Keyword(s):  
Calcium Hydroxide ◽  
Calcium Chloride ◽  
Setting Time ◽  
Calcium Sulphate ◽  
Sulphoaluminate Cement ◽  
Hydration Mechanism ◽  
Calcium Sulphoaluminate ◽  
Cement Setting

In order to clarify the adaptability of sulphoaluminate cement (SAC) and to improve the quality of SAC construction, several common calcareous compounds including calcium chloride, calcium sulphate and calcium hydroxide in designed content were introduced to SAC paste, respectively, following by the investigations of the corresponding fluidity degree and setting time. The experimental results show that calcium chloride in relative high content (no less than 1%) accelerates the cement setting, along with an enlarged degree of fluidity. As a comparison, the involvement of calcium sulphate in SAC paste does simply play a role of setting retarder by prolonging the setting time and enlarging the fluidity degree simultaneously. On the other hand, the presence of calcium hydroxide in SAC paste results in a state of being “neither setting nor flowable”, since the corresponding SAC paste shows a prolonged setting time and a remarkably lowered degree of the initial fluidity degree. All the phenomena can be explained from the viewpoints of hydration mechanism of dehydrated calcium sulphoaluminate.

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