Vertical Dimension Changes After Bioflx vs Stainless Steel Crowns in Primary Molars (BIOFLX-SSC-RCT)

April 6, 2026 updated by: Eman Adel Osman Hassan, Cairo University

Vertical Dimension Changes and Mean Biting Force Following Bioflx Placement Over Pulp-treated Primary Molars Versus Stainless Steel Crowns: A Randomized Controlled Trial.

this randomized controlled trial will compare Bioflx crowns and stainless-steel crowns in children with pulp-treated primary molars. The study will evaluate changes in vertical dimension and mean biting force after crown placement and will also assess parental satisfaction with esthetics and treatment impact. Eligible children aged 6 to 9 years will be randomly assigned in a 1:1 ratio to receive either a Bioflx crown or a stainless-steel crown. Measurements will be taken at baseline, immediately after crown placement, at 1 week, and at 4 weeks.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Early childhood caries commonly affects primary molars and often requires full-coverage restoration after pulp therapy. Stainless steel crowns are widely used because of their durability and clinical success, but they may have limitations related to esthetics and acceptance. Bioflx crowns are a more esthetic and flexible alternative, but there is limited evidence comparing their functional performance with stainless steel crowns.

This parallel randomized controlled trial will be conducted at the outpatient clinic of Pediatric Dentistry and Dental Public Health, Faculty of Dentistry, Cairo University, Egypt. A total of 18 children with pulp-treated primary molars will be enrolled and randomly allocated in a 1:1 ratio to receive either a Bioflx crown or a stainless steel crown.

The primary outcome is vertical dimension alteration measured in millimetres using a digital caliper. Secondary outcomes include mean biting force distribution measured by T-Scan digital occlusal analysis, parental satisfaction with esthetics, and parental satisfaction with treatment impact assessed by 5-point Likert scale questionnaires. Outcome measurements will be recorded at baseline, immediately after crown placement, at 1 week, and at 4 weeks, with parental satisfaction assessed at 4 weeks.

The purpose of this study is to determine whether Bioflx crowns provide comparable or improved functional and esthetic outcomes compared with stainless steel crowns in pulp-treated primary molars.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
18

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Egypt
    • Giza/Egypt
      • Cairo, Giza/Egypt, Egypt, 12613
        • Cairo University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Pulp-treated primary molars (pulpotomy)

    • Asymptomatic teeth after pulp therapy with no signs of infection, mobility, or radiographic pathology, such as internal resorption or periapical lesions
    • Age 6 years to 9 years
    • Male or female
    • Cooperative child with positive Frankl behavior rating
    • No missing teeth
    • Normal occlusion, including normal overjet and overbite
    • Free from systemic disease to allow continuity of follow-up

Exclusion Criteria:

  • Medically compromised or uncooperative children

    • Tooth indicated for extraction because of root resorption, teeth near exfoliation, or deep subgingival caries that prevents proper coronal seal
    • Teeth with more than two-thirds root resorption
    • Previous pulp therapy
    • Parafunctional habits, including bruxism, thumb-sucking, or other habits that may affect occlusal force measurements
    • Inability to attend follow-up visits or parental refusal to participate

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Bioflx Crown Group
Participants in this arm will receive Bioflx crowns after pulp therapy of primary molars. Crown placement will follow the study protocol, and outcomes including vertical dimension, mean biting force, and parental satisfaction will be assessed during follow-up.
Device: Bioflx Crown
Aesthetic full-coverage pediatric crown used after pulp therapy of primary molars. The Bioflx crown will be selected according to tooth size, adapted following the study protocol, and cemented with resin-modified glass ionomer cement.
Active Comparator: Stainless Steel Crown Group
Participants in this arm will receive stainless steel crowns after pulp therapy of primary molars. Crown placement will follow the study protocol, and outcomes including vertical dimension, mean biting force, and parental satisfaction will be assessed during follow-up.
Device: Stainless Steel Crown
Preformed stainless steel full-coverage pediatric crown used after pulp therapy of primary molars. The stainless steel crown will be selected according to tooth size, adapted following the study protocol, and cemented with resin-modified glass ionomer cement

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Vertical dimension alterations
Time Frame: Baseline, immediately after crown placement, 1 week, and 4 weeks
Change in inter-occlusal vertical dimension measured in millimetres using a digital caliper at baseline, immediately after crown placement, at 1 week, and at 4 weeks. Mean differences will be compared between the Bioflx crown group and the stainless steel crown group.
Baseline, immediately after crown placement, 1 week, and 4 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Mean Biting Force Distribution
Time Frame: Baseline, immediately after crown placement, 1 week, and 4 weeks
Occlusal force distribution on the restored tooth measured as a percentage using T-Scan digital occlusal analysis at baseline, immediately after crown placement, at 1 week, and at 4 weeks. Force distribution will be compared between the Bioflx crown group and the stainless steel crown group.
Baseline, immediately after crown placement, 1 week, and 4 weeks
Parental Satisfaction With Treatment Impact
Time Frame: 4 weeks
Parental ratings of the impact of treatment on the child, including comfort, chewing ability, well-being, and perceived improvement in appearance, assessed using a 5-point Likert scale questionnaire.
4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cairo University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Osama A El shahawy, PHD, Cairo University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

  • Almajed OS. Shaping Smiles: A Narrative Review of Crown Advancements in Pediatric Dentistry. Cureus. 2024;16(1):e52997. doi:10.7759/cureus.52997.
  • Mathew MG, Roopa KB, Soni AJ, Khan MM, Kauser A. Evaluation of clinical success, parental and child satisfaction of stainless-steel crowns and zirconia crowns in primary molars. J Family Med Prim Care. 2020 Mar 26;9(3):1418-1423. doi:10.4103/jfmpc.jfmpc_1006_19.
  • Rahate I, Fulzele P, Thosar N. Comparative evaluation of clinical performance, child and parental satisfaction of Bioflx, zirconia and stainless steel crowns in pediatric patients. F1000Res. 2023 Dec 21;12:756. doi:10.12688/f1000research.133464.2.
  • Maheshkumar K, Chowdhary N, Chowdharry R, Vundela RR, Sonnahalli NK, Anuraaga AT. Bite force evaluation at maximal intercuspal position: An in vivo comparative study between stainless steel and zirconia crowns on primary molar teeth. J Indian Soc Pedod Prev Dent. 2023 Apr-Jun;41(2):89-97. doi:10.4103/jisppd.jisppd_156_23.
  • Nair K, Chikkanarasaiah N, Poovani S, Thumati P. Digital occlusal analysis of vertical dimension and maximum intercuspal position after placement of stainless steel crown using Hall technique in children. Int J Paediatr Dent. 2020 Nov;30(6):805-815. doi:10.1111/ipd.12647.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 6, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 6, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 13, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 6, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CU-PD-2025-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared. The study involves a small sample of pediatric participants, and data confidentiality and participant privacy will be protected according to institutional and ethical requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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