This study conducted on thirty children aged 3-6 years old of both genders, have bilateral carious lower first primary molars. Pre-operative periapical x- ray were taken for both sides. The children were divided into 2 groups(SMART group and ART group). For Atraumatic Restorative Technique (ART technique), glass ionomer cement(GIC) was applied according to manufacturer's instructions. For Silver Modified Atraumatic Restorative Technique (SMART technique), SDF was applied carefully using bended micro sponge brush. It was applied directly to only the affected tooth surface. After one week GIC was applied according to manufacturer's instructions. Clinical and radiographic evaluation were done for all teeth at 6, 12 months. The data were collected then statistically analyzed using chi-square test to show the difference between groups.

Sample size calculation:

For this study, a sample size of 30 was obtained using unpaired two sample two tail z-test. The effect size (dz=2.813) and the required sample size were calculated for α =0.05 and a confidence power of 0.8039, assuming a normal distribution.

Patient selection: This study conducted on thirty children aged 3-6 years old of both genders. The children selected from Pediatric Dental Clinic, Faculty of Dentistry, Mansoura University. Included children in the study were. Apparent healthy and free from any systemic diseases or chronic conditions. Child should have bilateral restorable carious lower first primary molars, occlusal caries, International Caries Detection and Assessment System(ICDAS) score (4, 5), asymptomatic or have reversible pulpitis. Radiographic examination show intact lamina dura, absence of internal and external pathological root resorption or periapical infection.

Randomization. The study was spilt mouth design. The right side of all participants was done atraumatic restorative technique (ART) and the left side was silver modified atraumatic restorative technique (SMART technique).

Clinical procedures:

• Communication with the children were established.
• Pre-operative periapical x- ray were taken for both sides.
• Gross debris from cavitation were removed.
• Carious dentin on walls were excavated using spoon excavator and low speed contra with round or fissure bur.
• Areas to be treated were isolated with cotton rolls.
• Dryness of lesion with gentle flow of compressed air were done. Control group: Right side of the patient (ART technique) (group 1) (D1) :(20)
• GIC was applied according to manufacturer's instructions.

Experimental group: Left side of the patient (SMART technique) (group 2) (D2):(21)

• A protective coating was applied to the lips and skin to prevent a temporary henna-appearing tattoo that can occur if soft tissues come into contact with SDF.
• SDF was applied carefully using bended micro sponge brush. The brush was dipped into SDF and dabbed on the side of the plastic dish to remove excess liquid before application.
• SDF was applied directly to only the affected tooth surface of lower first primary molar.
• Excess SDF was removed with gauze, cotton roll, or cotton pellet to minimize systemic absorption.
• Application time was at least one minute. No more than one drop of SDF was used for the entire appointment.
• The lesion was dried for 15 seconds with gentle flow of compressed air.
• After one week GIC was applied according to manufacturer's instructions.

Evaluation:

All primary molars were evaluated clinically and radiographically at 6 and 12 months for the overall success/failure criteria:

• Presence/absence of {recurrent caries (catch with probe), pain (spontaneous, with eating, with percussion), clinical abscess, mobility}.
• Presence/absence of {internal root resorption, external root resorption, interradicular radiolucency, periapical radiolucency}.

Statistical Analysis:

The collected data were tabulated and statistically analyzed . The results were considered statistically significant at p≤0.05.

• Chi-Square test was performed to compare the significance between the groups in clinical and radiographic evaluation.
• Kappa index was performed to correlate between clinical and radiographic results.

Inclusion Criteria:

• This study conducted on thirty children aged 3-6 years old of both genders.
• children in the study were. Apparent healthy and free from any systemic diseases or chronic conditions.
• Child should have bilateral restorable carious lower first primary molars, occlusal caries, ICDAS score (4, 5), asymptomatic or have reversible pulpitis.
• Radiographic examination show intact lamina dura, absence of internal and external pathological root resorption or periapical infection.

Exclusion Criteria:

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