The goal of this clinical trial is to evaluate the child and parents satisfaction of Bioflx crowns compared to zirconia crowns in the restoration of primary molars. The main question[s] it aims to answer : Is there a difference in the child and parents satisfaction levels between BioFlx crowns and zirconia crowns in the restoration of primary molars?" The study will also assess the clinical performance of both types of crowns in terms of Retention, occlusal wear, gingival health, as well as preparation time.

The management of severely decayed primary teeth in pediatric dentistry often requires the use of crowns to restore function and aesthetics. Traditional stainless-steel crowns (SSCs) have been widely used due to their durability and cost-effectiveness; however, their metallic appearance and lack of aesthetic appeal have prompted the development of alternative materials such as zirconia and Bioflx crown. Zirconia crowns are recognized for their superior aesthetics and biocompatibility, making them a preferred choice for parents who prioritize appearance. However, they can present challenges in terms of retention, preparation requirements, and cost. Bioflx crowns, a newer material in pediatric dentistry, aim to combine aesthetic appeal with flexibility and improved adaptability to tooth anatomy. Despite their growing popularity, limited research directly compares the child and parental satisfaction between zirconia and Bioflx crowns. It remains unclear which material offers the best balance of functional, aesthetic, and patient-centered outcomes.This gap in knowledge hinders evidence-based decision-making when selecting crowns for pediatric patients. Zirconia crowns have gained prominence in pediatric dentistry as an alternative to stainless steel crowns for primary molars. While SSCs have long been valued for their durability and ease of placement, their metallic appearance often presents an aesthetic concern for parents and patients. Zirconia crowns provide a more natural, tooth-colored alternative, making them a preferred option in cases where aesthetics is a priority. One of the main advantages of zirconia crowns is their biocompatibility, as they demonstrate lower plaque accumulation and gingival inflammation. Additionally, zirconia crowns offer superior mechanical properties, including high flexural strength and excellent fracture resistance, making them a long-lasting restorative option. Their wear resistance further supports their use in pediatric patients, particularly those with heavy occlusal forces. This study stems from the need to bridge the gap in current research regarding the satisfaction and the effectiveness associated with Bioflx crowns. Understanding whether Bioflx crowns offer superior aesthetic and functional outcomes compared to Zirconia crowns could influence clinical decision-making in pediatric dentistry. This is especially relevant as parents increasingly seek restorations that provide both durability and a natural appearance for their children.

Inclusion Criteria:

• The Inclusion criteria:

  1. Children aged four to eight years old who are appearing healthy and free of any systemic disease according to parental history.
  2. Frankl's positive and definitely positive children.
  3. Children whose parent or guardian are willing to sign an informed consent.
  4. Children whose parent or guardian are willing to comply with follow-up visits.
  5. Primary molars indicated for crowns. • Exclusion criteria:
  1. Children with

Exclusion Criteria:

• The Exclusion criteria:

  1. Children with poor oral hygiene that may contribute to higher plaque levels and affect the clinical outcomes of the crown restorations.
  2. Children with history of allergies; Known allergies to dental local anesthesia or to the materials used in Bioflx crowns.
  3. Child with parafunctional habits.
  4. Molars with severe structural loss that may compromise crown retention.
  5. Presence of malocclusion such as crossbite or scissor bite.
  6. Primary molar with root caries.
  7. Primary molar with root resorption or furcation involvement.