Following the restoration of primary molars with stainless steel and bioflex crowns, an evaluation of the current state of oral hygiene in relation to the amount of microorganisms and gingival health in the oral cavity will be carried out.

Inclusion Criteria:

• Participants aged between 4 and 8 years.
• Pulp therapy treated primary molars on the contralateral side, requiring a full coverage restoration (split-mouth technique).
• No history of any antibiotic consumption 2 weeks before the procedure.
• No history of fluoride application 2 weeks before the procedure.

Exclusion Criteria:

• Special children with physical disabilities or emotional disturbances.
• Children are diagnosed with systemic diseases.
• Grossly destructed teeth with non-restorable crown structure.
• Primary teeth with shedding or pathological tooth mobility.

A total of 10 patients 4-8 years old will be selected according to the established inclusion and exclusion criteria. The study will be conducted on patients attending the outpatient clinic of the pediatric dentistry department, Faculty of Dental Medicine Al-Azhar.