The aim of this study is to compare the clinical and radiographic success of indirect pulp capping of vital young permanent teeth with deep caries using two-step antibacterial bonding system versus conventional one.

The study was carried out on patients attending outpatient clinic in Pediatric and Dental Public Health department- Faculty of Oral and Dental Medicine Cairo University- Egypt.

**Sample size: On searching, no previous studies were conducted using neither conventional bonding nor antibacterial bonding in indirect pulp treatment in young permanent teeth, so sample size will be measured by estimation rather than calculation.

So, all patients attended outpatient clinic in Pediatric and Dental Public Health department- Faculty of Oral and Dental Medicine Cairo University- Egypt, In the period from 1/8/2015 - 31/10/2015 were enrolled for this study if they compatible with eligibility criteria.

**Clinical Procedures:

I. Diagnosis:

Full personal, medical and dental history,clinical and radiographic examination.

II. Allocation concealment:

Selected envelopes will be opened in the first visit to allocate the patients to their treatment groups .

III.Intervention:

A- Experimental Group: Indirect pulp capping with Antibacterial Two-Step Bonding System:

1. Local anesthesia.
2. Isolation of tooth with rubber dam.
3. Opening of the cavity and the removal of undermined enamel using high speed hand-piece with copious air/water spray and round burs.
4. Caries at the lateral walls of the cavity and at the dentin-enamel junction is completely removed with excavators or low speed round burs.
5. Partial removal of carious dentin (only soft disorganized dentin is removed) on the pulp wall.
6. Washing the cavity with distilled water and dryness with triple airway syringe and sterile cotton.
7. Apply antibacterial light-cure, self-etching bonding agent (Clearfil SE Protect, Kuraray America, Inc.)
8. Light-cured bulk fill composite (x-tra fil, VOCO) will be used as final tooth restoration.
9. Postoperative digital radiograph will be taken as a base line.

B- Comparative Group: Indirect pulp capping with Conventional Two-Step Bonding System Same as that of the experimental group EXCEPT steps number 5 as conventional light-cure, self-etching bonding agent (Clearfil SE Bond, Kuraray America, Inc.) will be applied into cavity according to manufacturer's instruction.

IV. Follow up and postoperative instructions:

- Patients will be recalled 48 hours after the treatment then at 2, 9 months

Inclusion Criteria:

1. Patients free from any systemic diseases.
2. Young permanent molars with deep carious lesions according to clinical and radiographic examination and at risk of pulp exposure if complete caries is removed.
3. Absence of clinical pathologic signs (fistula, swelling and abnormal tooth mobility)
4. The absence of clinical symptoms of irreversible pulpitis such as spontaneous pain or pain persisting after the disappearance of the existing stimulus or sensitivity to pressure.
5. Absence of adverse radiographic findings (interradicular or periapical radiolucencies, thickening of the periodontal membrane space, internal and external root resorption).
6. Compliant patient/parent.

Exclusion Criteria:

1. Teeth with previous restorative treatment.
2. Unrestorable teeth.
3. Uncooperative patients.