Background: In Children Dental decay affects both primary and permanent teeth is a serious global health problem. To maintain the integrity of the primary dentition, the damaged teeth may be restored with a full coronal restoration. Stainless steel crowns (SSC)were the gold standard crowns used. In order to achieve aesthetics various tooth coloured crowns have been used . Aim and objective: The study aim is to evaluate the clinical efficacy of recently developed tooth-colored Bioflex crowns and prefabricated stainless steel crowns. The study's primary goal is to assess the retention of the crown, gingival health, stains surrounding the crown, and parental satisfaction during a 6 month follow up. Materials and methodology: The present in vivo study was conducted in 25 children aged 4-9yrs as a split mouth design in maxillary and mandibular primary molars for deep dental carious lesion and pulp involved teeth , where all the right side teeth were treated with Bioflex crowns and left side were treated with SSCrowns Results and conclusion: The data was analysed using Ttest and the overall success rate with Bioflex crowns was 96% and SScrowns was 97.3%. Bioflex crowns can be option for posterior restoration when esthetics is of prime concern.