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NCT Number: NCT06968767

Preparation Time Of Bioflx Crowns Compared To Zirconia Crowns On Primary Molars

This study aims to evaluate and compare the preparation time required for Bioflx crowns versus zirconia crowns on primary molars through a randomized clinical trial.

• Primary Objective: To compare the preparation time required for Bioflex crowns and zirconia crowns on primary molars in pediatric patients.

• Secondary Objectives:

To evaluate the clinical performance of Bioflex crowns compared to zirconia crowns, including:

Retention, Patient Satisfaction, Parental Satisfaction, Occlusal Wear and Gingival Health.

the main question it aim to answer: Is there a significant difference in the preparation time required for Bioflx crowns compared to zirconia crowns in the primary molars of pediatric patients?

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Key information

Age range

4 year–8 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Faculty of Dentistry Cairo University

Cairo, Egypt, 12613

Location contact

faculty of dentistry cairo university

CONTACT

[email protected]

0020223642705

hala mosaed ali alshaeri, bachelore of dental science

PRINCIPAL_INVESTIGATOR

About this study

In pediatric dentistry, achieving efficient and aesthetic restoration of primary molars remains a significant challenge, particularly when treating young or anxious patients who may struggle with long or complex procedures. Zirconia crowns are widely used due to their durability, excellent biocompatibility, and natural tooth-like appearance, making them the gold standard for full-coverage aesthetic restorations in children. However, their placement involves extensive tooth preparation, which results in longer chair time and an increased risk of pulp exposure. These factors can negatively impact both treatment outcomes and patient behavior management.

Bioflex crowns have emerged as a potential alternative, offering a more flexible and user-friendly design that simplifies placement and reduces the amount of tooth preparation required. This may result in shorter procedure times and improved patient comfort. Despite these potential benefits, there is currently limited clinical evidence comparing the preparation time and efficiency of Bioflex crowns versus zirconia crowns for restoring primary molars.

This gap in knowledge makes it difficult for clinicians to make fully informed decisions about which crown system offers the best balance of procedural efficiency, aesthetics, and patient cooperation. By directly comparing Bioflex and zirconia crowns in terms of tooth preparation time and overall clinical practicality, the proposed study aims to determine whether Bioflex crowns provide a significant advantage in pediatric settings. The results could help identify the most time-efficient and effective restorative option for primary molars, ultimately improving care outcomes for pediatric patients.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Children aged between 4 and 8 years with a primary molar that needs to be covered by a crown.

Medically healthy children (ASA I or II according to the American Society of Anesthesiologists classification).

Children whose parent or guardian is willing to sign an informed consent.

Children whose parent or guardian are willing to comply with follow-up visits.

Frankl's positive and definitely positive patient.

Exclusion criteria

  • Molars with severe structural loss that may compromise crown retention.

Children with poor oral hygiene that may contribute to higher plaque levels and affect the clinical outcomes of the crown restorations.

Children with a history of allergies; known allergies to dental local anesthesia or to the materials used in Biofix crowns.

Children with any systemic conditions or disabilities that may affect their ability to participate in the study.

Treatment and study plan

bioflx crown

Other

(Group A: Preformed Biofix Crown - Assigned Intervention)

Crown Selection & Tooth Preparation:

Measure the mesiodistal width using calipers to select an appropriately sized crown. If a mesial or distal wall is missing, use the contralateral tooth for size selection. Choose the crown that closely matches the measured mesiodistal width. Select the smallest crown that preserves proximal contacts using a trial-and-error approach. If crimping is necessary, use Howe's pliers.

Perform 1-1.5 mm occlusal reduction using a tapered diamond bur.

Reduce proximal areas by approximately 0.5 mm to clear the contact area.

Crown Placement & Cementation:

Ensure a snug fit of the selected crown. Apply a thin layer of glass ionomer cement inside the crown. Seat the crown firmly using finger pressure. Have the child bite down gently to ensure proper seating.

Final Adjustments & Cleanup:

Remove excess cement with floss or an explorer. Verify the crown's fit, occlusion, and stability.

zirconia crown

Other

Group B: Preformed Zirconia Crown - Assigned Intervention)

Crown Selection:

Measure the mesiodistal width using calipers to select the appropriate crown. If a mesial or distal wall is missing, use the contralateral tooth for size selection. Choose the one that closely matches the mesiodistal width. Select the smallest crown that preserves proximal contacts.

Tooth Preparation:

Reduce the occlusal surface by 1.5-2 mm using a tapered diamond bur.

Reduce interproximal areas by 1-1.5 mm, ensuring a feather-edge finish.

Perform a 1-2 mm subgingival preparation in passively placed fissure bur.

Crown Placement & Passive Fit Check:

Place the selected crown on the prepared tooth.

Cementation of the Crown:

Apply a thin layer of glass ionomer cement inside the crown. Seat the crown with passive finger pressure. Have the child bite down gently to ensure seating.

Primary outcomes

  1. prepration time

    Time frame: time frame: T0: 0 basline, follow up 12 month

    measured by stop watch per minutes

Secondary outcomes

  1. Occlusal wear of crown

    Time frame: T (Time): 12 months Intervals: T0: 0, T1: 3 months, T2: 6 months, T3: 12 months

    Measure: By Modified United States Public Health System criteria

    Criteria:

    Alpha: Occlusal surface intact

    Bravo: Wear of occlusal surface without tooth surface exposure

    Charlie: Wear of occlusal surface with exposure

    Measure: By Modified United States Public Health System criteria

    Criteria:

    Alpha: Occlusal surface intact

    Bravo: Wear of occlusal surface without tooth surface exposure

    Charlie: Wear of occlusal surface with exposure

    Measure: By Modified United States Public Health System criteria

    Criteria:

    Alpha: Occlusal surface intact

    Bravo: Wear of occlusal surface without tooth surface exposure

    Charlie: Wear of occlusal surface with exposure

  2. retention

    Time frame: Follow-up: 12 months Intervals: T0: 0, T1: 3 months, T2: 6 months, T3: 12 months

    Measure: By Modified United States Public Health System criteria

    Criteria:

    Alpha: Intact

    Bravo: Chipped/loss of material

    Charlie: Complete loss of crown

  3. Gingival Health

    Time frame: 12 months Intervals: T0: 0, T1: 3 months, T2: 6 months, T3: 12 months

    Measure: By Gingival Index

    Scores:

    0: Healthy gum

    • Mild inflammation and edematous gingiva, no bleeding on probing
    • Red edematous and shiny gingiva, bleeding on probing
    • Red edematous and ulcerated gingiva, spontaneous bleeding
  4. Child and parental satisfaction

    Time frame: T (Time): 12 months Intervals: T0: 0, T1: 3 months, T2: 6 months, T3: 12 months

    Measure: By 5-point Likert scale (Units of measurement)

    • Very happy
    • Happy
    • Neither
    • Unhappy
    • Very unhappy Questionnaire Type: Ordinary or N/A (Existing validated tool)

Study contacts

Contact information is provided by the study sponsor or research team.

Manal A Elshiekh, prof, phd

CONTACT

[email protected]

0223642705 ext. 002

halah M alshaeri, Bachelor of Dental surgery

CONTACT

[email protected]

00201149038858 ext. 002

Sponsors and collaborators

Lead sponsor

Cairo University

Other

Registry information

Official study title

Evaluation Of Preparation Time Of Bioflx Crowns Compared To Zirconia Crowns On Primary Molars

Important dates

Study start
2025
Primary completion
2025
Study completion
2026
First posted
May 13, 2025
Registry last updated
May 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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