Minimally Invasive Demineralized Hard Tissue Repair: Remineralization Dr. Anshuman Khaitan Dr. Dhanyakumar N.M. Dr. Jayakumar T Dr. Vasundhara Shivanna PG student Professor & head Reader Professor Department of Conservative Dentistry and Endodontics Abstract: and whole saliva are supersaturated with respect to most Caries is a disease caused by a multifactorial process and it solid calcium phases. However, precipitation of calcium remains a major public health problem in most phosphate phases in saliva normally does not occur, due to communities even though the prevalence of the disease the presence of salivary proteins, particularly statherin has decreased. One of the recent trends in caries control and proline-rich phosphoproteins. The proposed includes minimally invasive treatment of the lesions by mechanism of action is that the segments of the proteins reversal of mineral loss by remineralization. Restorative containing phosphoseryl residues, in particular the treatment options are advised only when the carious statherin sequence, bind to calcium and phosphate ion process has resulted in more extensive damage, and form, clusters, preventing growth of the ion cluster to the critical function or esthetics need to be restored. This article size required for precipitation and transformation into a reviews the various remineralization stratezies and their crystalline phase. This critical stabilization of calcium and role in remineralizing tooth structure. b phosphate ions by salivary phosphoproteins ensures that . ---~-~-~ the ions remain bioavailable to diffuse into mineral Intro d uction: /m/ ~'- deficient .. lesions to allow for remineralization . .. Tr~diti~nally, the management of a carious THE CARlES BALANCE of demineralized crystals, while preventing lesion mvolves invasive operative and . ~\~'F~ surface deposition in the form of calculus. surgical approach which can result in'" However, net remineralization produced tissue loss and patient discomfort. One by saliva is small and is a slow process, of the most important concepts that have with a tendency for the mineral gain to be evolved in cariology in the past several F~ in the surface layer of the lesion due to decades is the demineralization and E.__ / the low ion concentration gradient from remineralization of enamel. I H.~LTy saliva into the lesion." The ratio between demineralization and _/ The question now becomes how one can help remineralization is crucial, determining the ~ naturally occurring hardness and strength of tooth structure. If the processes to arrest lesion demineralization phase continues for a long period of activity, repond to mineral time, due to fall in pH, excessive loss of minerals results dissolution by remineralization which leads to loss of enamel structure and cavitation effort, and thus potentially reverse leading to caries. early carious lesions.' Where When the pH individual lesions or cavities are rises, the reverse concerned, the treatment options t a k e s p Iace, are to restore or not to restore. If res u Itin gin the decision is made not to restore, de po sit ion 0 f the question arises, can the lesion minerals back to or cavity be cured, or at least prevented from further the too t h extention; in other words, can it be arrested?' _~i...ol.;._.structure." Fig 1. The best way of managing early carious lesion involves remineralization of the enamel with the aid of The ability of saliva to remineralize demineralized enamel remineralization products, A variety of these products are crystals stems from its ability to supply bioavailable available. This article reviews the various calcium and phosphate ions to the tooth. At physiological remineralization strategies and their role in pH, unstimulated and stimulated parotid, submandibular, remineralizing tooth structure, . Mimimally Invasive Demineralized Hard Tissue Repair: Remineralization 34 Various RemineralizingAgents And Methods: dissolve in that fluid to liberate ions capable of diffusing into the enamel subsurface lesion. The dissolution of the Fluorides: Fluoride ions calcium phosphate phase in saliva requires that saliva be promote the formation of undersaturated with respect to that crystalline phase. fluorapatite in enamel in the Based on some typical concentrations of calcium, presence of calcium and phosphate, and fluoride ions in saliva, the pH at which the phosphate ions produced various crystalline phases will dissolve has been during enamel calculated. These calculations show that, at the normal pH demineralization by plaque Application of range of saliva, these crystalline calcium phosphate bacterial organic acids.' fluoride varnish phases would not dissolve. Furthermore, localization of This is now believed to be the major mechanism of significant quantities of solid calcium phosphate phases at fluoride ion's action in preventing enamel the tooth surface is problematic.' demineralization. Fluoride ions can also drive the remineralization of previously demineralized enamel if Casein phosphopeptides (CPP): The casein enough salivary or plaque calcium and phosphate ions are phosphopeptides (CPP) are approximately 10% (w/w) of available when the fluoride is applied. The non-invasive the protein casein. They are tasteless, have low treatment of early caries lesions by remineralization has antigenicity, and can be purified as CPP-ACP( casein the potential to be a major advance in the clinical phosphopeptide - amorphous calcium phosphate) management of the disease. However, for every two complexes from a casein enzymic digest by filtration.' fluoride ions, 10 calcium ions and six phosphate ions are Four major bovine CPPs containing the sequence -Ser(P) required to form one unit cell of fluorapatite. Hence on - Ser(P) - Ser(P) - Glu - Glu -, where Ser(P) represents a topical application of fluoride ions, the availability of phosphoseryl residue, have been shown to stabilize high calcium and phosphate ions can be the limiting factor for concentrations of calcium and phosphate ions in net enamel remineralization to occur and this is highly metastable solution supersaturated with respect to the exacerbated under xerostomic conditions.' When calcium phosphate solid phases at acidic and basic pH.IO adequate levels of calcium and phosphate ions are This interaction prevents growth of the calcium and together with the fluoride ions, it has been shown in vitro phosphate ion clusters to the critical size required for that this combination can produce substantial nucleation and phase transformations. II remineralization of lesions of enamel and even those Potential benefits have been shown for casein penetrating the underlying dentin.' phophopeptides, amorphous calcium phosphates, and Calcium based products: other approaches. Inhibition of enamel and dentin demineralization, promotion of remineralization, and a Fluoride alone cannot achieve remineralization; calcium slow - down of the caries process as well as regression of and phosphate ions are necessary for remineralization to subsurface lesions have been reported for casein occur. The calcium and phosphates in saliva are the phosphopeptide - amorphous calcium phosphate(CCP- primary source for remineralization. Remineralizing ACP).12 agents seek to promote remineralization through increase of bioavailable calcium and phosphate ions that become The main function of casein phosphopeptides is to incorporated in the tooth structure. Supplementing modulate bioavailability of calcium phosphate levels by calcium and phosphates is likely to have a positive effect, maintaining ionic phosphate and calcium supersaturation in particular when effective fluoride levels are available at to increase remineralization. The role of ACP is also said the same time. 5 to control the precipitation of CPP with calcium and phosphate ions. 13 Various calcium based systems are: Combined with fluoride, CPP -ACP has an additive effect Crystalline calcium phosphate remineralizing systems: on caries activity. Use of CPP - ACP along with fluoride- Calcium phosphate can exist in one of numerous containing dentifrice has proved to be beneficial in crystalline phases. Each of these crystalline phases has reducing the demineralization around orthodontic different solubilities, and many have been tested as brackets and remineralizing white spots caused by potential methods of delivering calcium and phosphate demineralization. Adding CPP - ACP to soft drinks can ions to subsurface enamel lesions. The problem with reduce their erosion capacity.' applying crystalline material to the oral cavity to promote enamel remineralization is the poor solubility of the Mechanism of action for CPP - ACP: CPP-ACP has calcium phosphate phases, such that the calcium and been determined to be amorphous electroneutral phosphate ions are unavailable for remineralization. nanocomplexes with a hydrodynamic radius of 1.53 + These crystalline calcium phosphate phases must be 0.04 nm and 2.12 + 0.26 nm, respectively. From the size released from the product on contact with saliva and then and electroneutrality of the nanocomplexes, it would be Mimimally Invasive Demineralized Hard Tissue Repair: Remineralization 35 - ------ - - -- expected that they would enter the porosities of an enamel acid etching. Another approach to improve current subsurface lesion and diffuse down concentration remineralization systems is to improve the biomimetic gradients into the body of the subsurface lesion. Recently, peptides used to stabilize, deliver, and control it has been shown, with confocal laser