Comparative Clinical Evaluation of BioFlx, Zirconia, and Stainless-Steel Crowns in Primary Molars

Inclusion Criteria: * Children who are free from any systemic disease. * Children with a carious lower primary molar indicated for crown restoration. * Teeth with an intact antagonist and neighboring primary molar. * Cooperative children with scores 1 and 2 (positive or definitely positive) according to Frankl's behavior rating scale. Exclusion Criteria: * Children with extremely poor oral hygiene. * Teeth showing radiographical furcation involvement or root resorption. * Children with para-functional habits, bruxism, or deep bite. * Teeth with inadequate non-restorable crown structure.