This study will be performed to assess the effect of inert prepared tooth paste loaded with Calcium Silicate Nanoparticles (CSNPs) and compare it to another one containing Sodium Fluoride Nanoparticles in the management of patients complaining of hypersensitivity and laboratory investigating the efficacy of CSNPs and NaFl Nps containing toothpaste in dentinal tubules occlusion.

Hypersensitivity has been defined as the pain arising from exposed dentin, typically in response to chemical, thermal, tactile or osmotic stimuli that cannot be explained as arising from any other form of dental defect or pathology. The pain of dentin hypersensitivity is classically, short, sharp, of rapid onset in character and of the duration of the applied stimuli. hypersensitivity was first documented by Blum. Although much has been learnt about hypersensitivity overtime, yet the mechanism of pain was explained by several hypotheses welling to be aware about the nature of the Disease firstly was the hypothesis that dentin was innervated and therefore, nerves were directly triggered by the stimulus. A further theory, termed the odontoblast transducer mechanism. Currently, the most widely accepted theory is the hydrodynamic theory which determined that there was an outward flow of fluid along the dentinal tubules.

In addition to extrapolation of the pain mechanism, allocating the etiology and the risk factors have a crucial impact on the disease outcome as well as the line of treatment. For hypersensitivity to occur lesion localization, where the dentin surface of a tooth must be exposed. And a lesion initiation must take place where the number of dentin tubules in close proximity to each other must be patent from the pulp to the oral environment.

Several in vitro and in situ data, case report data and epidemiological surveys summarized the most common etiologic and risk factors in the two main causes: gingival recession exposing dentin, either by periodontal Disease, zealous brushing, smoking and loss of hard tissue exposing dentin, also by frank carious lesions with dentin exposure of smooth tooth surface or development of non-carious cervical lesions.

Eventually based on the great knowledge about hypersensitivity nature, Etiologic and risk factors the dental professionals can now select the appropriate line of treatment either with conservative non-surgical intervention ex; Elimination of etiological factors, addition of desensitizers to toothpastes like Potassium nitrate, Strontium, Arginine and Calcium Carbonate, Calcium Sodium Phosphosilicate. Use of Dentin desensitizing products which have different ingredients, such as fluoride, hydroxyethyl methacrylate, glutaraldehyde, oxalate and potassium nitrate, as well as a combination of these ingredients.

Several in vitro, in situ as well as in vivo studies tackled the immense remineralizing capabilities of calcium silicate and it's in vitro promising results in formation of hydroxyapatite on enamel as well as occluding dentinal tubules thus giving potential anti-hypersensitivity benefits. However in vivo anti-hypersensitivity benefits were not tackled enough in literature.

This study will be performed to clinically assess the effect of toothpaste loaded with calcium silicate Nanoparticles (CS NPs) and compare it to one loaded with Sodium fluoride Nanoparticles (NaFL NPs) in the management of dentin hypersensitivity and laboratory investigating their efficacy in dentinal tubules occlusion. The null Hypothesis is the CS NPs has the same effect as Na FLNPs in the management of hypersensitivity complaining patient. The alternative hypothesis is the dentinal tubules occlusion by CSNPs will be like that one produced by Na FLNPs.

Inclusion Criteria:

• Hypersensitive areas on facial surfaces of the teeth (incisors, cuspids, bicuspids, and first molars with exposed cervical dentine)
• Areas with hard tissue erosion
• cuneiform defect, pathological abrasion.
• Gingival recession
• Good overall physical health
• Age between 20 to 40 years; and provision of written informed consent

Exclusion Criteria:

• chipped teeth
• Defective restorations
• fractured un displaced cuspids
• deep dental caries
• deep periodontal pockets
• orthodontic appliances, dentures, or bridgework that would interfere with the evaluation of hypersensitivity.
• periodontal surgery within the previous 6 months.
• ongoing treatment with antibiotics and/or anti-inflammatory and/or analgesic drugs.
• ongoing treatment for tooth hypersensitivity, pregnancy, or lactation; heavy smoking and alcohol or drug abuse.

for anyone

The operator, the assessor as well as the data analyst will be blinded to material assignment.