Composition & Mode of Action
D-SOLV’ is available in a dual syringe and consists of 2 components that are mixed immediately before treatment. Component 1 contains: * Amino acids: leucine, lysine and glutamic acid in de-ionized water. * Sodium hydroxide (NaOH) * Sodium chloride (NaCl) * Carboxymethyl cellulose Component 2 contains: * Sodium hypochlorite.(NaOCl)
Mode of action
To understand the Mode of Action of D-Solv’; let’s first understand the structure of collagen and how dental caries is formed. Dentine consists of (70% wt) inorganic portion, (10%wt) water and an (20%wt) organic matrix. Of this 20% organic matrix; 18% is collagen and 2% non-collagenous compounds. Collagen contains large number of amino acids like proline glycine, hydroxyproline etc. These amino acids form a repeating sequence which is known as a polypeptide chain.. The polypeptide chains are coiled into triplet helices called tropocollagen units. These tropocollagen units then re-orient side by side to form a fibril. Covalent bonds between polypeptide chains and the tropocollagen units form cross-links and give the collagen fibrils stability. When caries occurs, dentineal tubules provide access for penetrating acids and subsequent invasion of bacteria. This results in a decrease in pH which further causes acid attack, demineralization and dissolution of organic and inorganic matter.
When components 1 and 2 of D-Solv’ are mixed the three differently charged amino acids (lysine = positive, glutamic acid = negative, and leucine = neutral) combine with NaOCl and form chloramines at a high pH. The peptide chains of all proteins, including collagen, are made up of hydrophilic (positively or negatively charged) and hydrophobic patches. So each of the three chloroamino acids in D-Solv’ electrostatically attracts one of these patches, effectively bringing reactive power to the full length of the target, the collagen fiber, while minimizing unwanted side-reactions from hypochlorite. The formation of chloramines reduces the reactivity of the chlorine without altering its chemical function.
The chlorinated amino acids are able to disrupt the several types of electrostatic bonds that hold the fibrous structure together. The binding of Chlorine to the amino group is unstable and therefore: In carious dentine; Chlorination of denaturated collagen is possible; and the conversion of hydroxyproline to pyrrole-2-carboxylic acid, initiates the disruption of altered collagen fibers within the carious dentine. Also cleavage by oxidation of glycine residues could also be involved. Along with Electrostatic interactions; Diffusion also occurs. NaOCl alone is not able to release the proteins' covalent peptide bindings. Only the combination of the three differently charged amino acids in the right proportion results in different reactions between the chloro-amino acids and the denatured dentine:
The chemical result of these processes is a breakdown of degraded collagen characteristically found in the dematerialized portion of a carious lesion. The amino acids reduce the hypochlorite's aggressiveness so that only the denatured collagen in the dentine damaged by caries is dissolved, not the intact collagen in healthy dentine. The degraded collagen has an open structure and is therefore more susceptible to further breakdown by chloramines. The porous nature of demineralized dentine allows D-Solv’ to penetrate. The unaffected collagen is more resistant to degradation, but the framework of degraded collagen in the porous mineral is broken down and can easily be scraped off. Sound and carious dentine become easily separable clinically: Thus the carious dentine is easier to dislodge than the sound dentine.
* During use, the pH value is 11. Organic tissue becomes hydrophilic due to the high pH. This enables the chloro-amines to penetrate into the demineralized dentine.