Dental caries is a biofilm-mediated, sugar-driven, multifactorial, dynamic disease that results in the phasic demineralization and remineralization of dental hard tissues.

These tissues have poor regeneration capability because of the lack of both regenerative cells and vascularization.

In the complex caries progression process involving dietary sugars, bacterial metabolism and demineralization, the collagenous organic matrix becomes exposed and destroyed by resident and bacterial proteases, allowing the lesion to expand

It is possible to find numerous noninvasive or minimally invasive therapies for caries such as hygiene education, fluorides, Phosphopeptide compounds, xylitol and infiltrative resins.

However, when caries progresses to the point of breaking down the dental tissues, composite restorations are imperative to preserve the tooth functionality.

During the execution of routine dental restorations, the hybrid structure formed by the dental bonding procedure occurs through the interaction and subsequent polymerization of monomers around the demineralized collagen matrix.

The oral cavity is a severe environment for the resin-dental bond to survive for a reasonable length of time, with thermomechanical changes, chemical attacks by acids and enzymes and other factors posing routine daily challenges. Therefore to achieve effective and stable bonding, the preservation of dentin collagen is critical, since collagen represents the major organic component of the dentin matrix.

Based on today's understanding of the dental biomineralization process, new efforts have been made to develop synthetic analogues of non-collagenous proteins (NCPs), which are involved in the events of nucleation and growth of hydroxyapatite crystals in hard tissues Such analogues have been designed mirroring the amphiphilic characteristics of NCPs, with polar groups complexing inorganic ions and non-polar side chains governing the matrix-matrix interactions.

Inclusion Criteria:

• Patients included in the study will be required to present at least one permanent molar with an active deep carious lesion without pulpal involvement.
• Age of patient: 18 -30 years
• Carious lesions will be standardized by means of clinical and radiographic examinations performed before the procedures

Exclusion Criteria:

• Teeth with deep dentinal lesions with pulpal involvement, abscess, pain or swelling
• Developmental disorders and adjacent soft tissue lesions
• Patients with systemic illness will be excluded