Carious Primary MolarsNCT06933927
Comparative Evaluation of Gingival Health and Bacterial Adhesion in Bioflx vs. Zirconia Crowns on Primary Molars
A study testing (Group A: Bioflx crowns) and (Group B) : Preformed Zirconia crown in people with Carious Primary Molars, run by Cairo University at 1 site in Egypt.
Trial summary
The goal of this clinical trial is to evaluate the Evaluation of Gingival Health and Bacterial Adhesion of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars of Bioflx crowns compared to zirconia crowns in the restoration of primary molars. Read more about this study
- Who is it for?
- Ages 4 to 8 years
- Conditions the study is for
- Carious Primary Molars
- What is being tested?
- (Group A: Bioflx crowns) and (Group B) : Preformed Zirconia crown
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 28 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Jun 2025to 26 Feb 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 4 to 8 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- patients aged 4-8 years.
- decayed in primary molars require full-coverage crowns.
- No history of systemic diseases affecting oral health.
- Cooperative children.
Who cannot join
- -patients with severe medical conditions, badly decayed in primary molars and trauma.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Egypt1 site
Faculty of dentistry cairo university
Cairo, Giza Governorate, 12613
About this study
Official title: Evaluation of Gingival Health and Bacterial Adhesion of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars: A Randomized Clinical Trial
The goal of this clinical trial is to evaluate the Evaluation of Gingival Health and Bacterial Adhesion of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars of Bioflx crowns compared to zirconia crowns in the restoration of primary molars. The main question[s] it aims to answer is there are the differences in bacterial adhesion and gingival health between bioflx and zirconia crowns The study will also assess the clinical performance of both types of crowns in terms of bacterial adhesion , child and parents satisfaction,as well as preparation time.
Read the detailed description
Dental caries is an oral disease most ubiquitous among children, characterized by a series of demineralization and remineralization cycles. If left untreated, it can progress to cavitated lesions. Usually, the familiar method of managing multi-surface carious lesions in primary teeth with stainless steel crowns .Streptococcus mutans is considered to be the main colonizer and primary etiological factor in caries progression as it stimulates the production of glucans from the food substrates. Research has indicated that S. mutans can be isolated from plaque samples. Consequently the long-term success of a restored tooth is significantly affected by the adhesion of S. mutans to the preformed crowns.Bacterial adhesion on zirconia are sparse. An in vitro study reported the initial bacterial adhesion on the surface of zirconia to be less compared with resins. When a primary tooth is restored with a full-coverage restoration, it establishes a fresh environment conducive to microbial adhesion. Bioflx Crowns the first flexible, durable, and esthetic preformedcrown for primary molars .BFCs are monochromatic, metal-free, tooth-colored crowns used in the medical device industry having high strength, flexibility, and durability. These crowns are autoclavable and are similar to SSC in tooth preparation. Additionally, they offer a cost benefit compared to zircon crowns,
- Conditions
- Carious Primary Molars
- Being tested
- (Group A: Bioflx crowns), (Group B) : Preformed Zirconia crown
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
(Group A: Bioflx crowns)Other
Minimal preparation will be required due to their flexural adaptability:1. Choose an appropriately sized Bioflex (Nusmile) crown of similar size to the mesiodistal width.2. The tooth will be prepared using a flame stone for occlusal reduction by 1-1.5 mm, including the central groove .3Proximal preparation will be around 0.5 mm, by using a fine, long, tapered diamond stone to cut interproximal slices mesially and distally.4. The crown will be placed with a snug fit and cemented using glass ionomer
(Group B) : Preformed Zirconia crownOther
- Size Determination can be achieved by holding a crown up to the existing tooth or, if available, using digital x-ray measurements to match the patient's interproximal width to the corresponding crown size.2. OcclusalPerform an occlusal reduction of about 1.5-2 mm, ensuring adequate space for the crown material. 3. Axial ReductionReduce the buccal and lingual surfaces uniformly, ensuring the removal of any prominent buccal bulges to allow for a passive crown fit. 4. Interproximal ReductionClearance: Ensure sufficient interproximal space by removing enough tooth structure to allow the crown to seat without interference.5. Subgingival PreparationMargin Placement: Extend the preparation subgingivally by approximately 2 mm to achieve optimal crown retention and aesthetics. This involves removing the chamfer margin at the tissue level and ensuring a smooth transition from the root to the coronal tooth structure
| Study group | Role | What they receive |
|---|---|---|
| Bioflex crowns | Experimental | Bioflx Crowns (BFCs) the first flexible, durable, and esthetic preformedcrown for primary molars .BFCs are monochromatic, metal-free, tooth-colored crowns used in the medical device industry having high strength, flexibility, and durability. These crowns are autoclavable and are similar to SSC in tooth preparation. Additionally, they offer a cost benefit compared to zircon crowns Receives: Other: (Group A: Bioflx crowns) |
| Zirconia crowns | Experimental | zirconia crowns are frequently chosen as a comparator due to their established clinical performance and favorable biological properties. Studies have demonstrated that zirconia crowns exhibit lower bacterial adhesion, particularly of Streptococcus mutans, compared to stainless steel crowns (SSCs). highly polished and smooth surface of zirconia, which minimizes plaque accumulation and subsequent gingival inflammation. Receives: Other: (Group B) : Preformed Zirconia crown |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gingival Health
plaque index using Silness\& Löe plaque index:0 - 3 0: no plaque.1: film at gingival margin.2: moderate accumulation.3: abundance of plaque.
Measured: 6 months
Gingival health
Gingival index using Löe\& Silness :0 - 3 0: healthy gum.1: mild discoloration and edematous gingiva, no bleeding on probing.2: red oedematous and shiny gingiva,bleeding on probing.3: red oedematous and ulceration gingiva, spontaneous bleeding.
Measured: 6 months
Secondary outcomes (3)
Bacterial adhesion
Method of measurement : by( Mitis salivarius agar) Unit of measurement :Colony-formingunits.
Measured: 2 weeks
child and parental satisfaction
5-Point likert's scale / Questionnaire.
- Very Happy.2. Happy.3. Neither.4. Unhappy.5. Very Unhappy.
Measured: 6 months
Preparation time
Method of measurement : stop watch Unit of measurement : minutes
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2025
- Study start1 Jun 2025 (estimated)
- Primary completion30 Dec 2025 (estimated)
- Study completion26 Feb 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Carious Primary MolarsStudies of the same condition, open and under way.
- More trials run by Cairo UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cairo University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Salma Ahmed Abdelrazig Mohammed, Cairo University
- Investigators
- Manal Ahmed Elsheikh, PHD, Study director, Cairo UniversityShaimaa Mohamed Sabry mostafa, PHD, Study director, Cairo University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06933927
- Sponsor's protocol ID
- EGHBA-BFXZRC-PM-2025
- Status last verified
- Apr 2025
- First submitted
- 10 Apr 2025
- Last updated
- 22 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Patil AS, Jain M, Choubey S, Patil M, Chunawala Y. Comparative evaluation of clinical success of Stainless Steel and Bioflx crowns in primary molar - A 12 month split mouth prospective randomized clinical trial. J Indian Soc Pedod Prev Dent. 2024 Jan 1;42(1):37-45. doi: 10.4103/JISPPD.JISPPD_484_23. Epub 2024 Apr 15.
PubMed 38616425Bin AlShaibah WM, El-Shehaby FA, El-Dokky NA, Reda AR. Comparative study on the microbial adhesion to preveneered and stainless steel crowns. J Indian Soc Pedod Prev Dent. 2012 Jul-Sep;30(3):206-11. doi: 10.4103/0970-4388.105012.
PubMed 23263423
Study at a glance
From the registry record, last updated by the sponsor on 22 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Gingival Health and Bacterial Adhesion of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT06933927
- Acronym / sponsor ID
- EGHBA-BFXZRC-PM-2025
- Conditions
- Carious Primary Molars
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 28 participants (estimated)
- Lead sponsor
- Cairo UniversityUniversity, hospital or other
- Study start
- 1 Jun 2025 (estimated)
- Primary completion
- 30 Dec 2025 (estimated)
- Study completion
- 26 Feb 2026 (estimated)
- First posted
- 18 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to evaluate the Evaluation of Gingival Health and Bacterial Adhesion of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars of Bioflx crowns compared to zirconia crowns in the restoration of primary molars. The main question[s] it aims to answer is there are the differences in bacterial adhesion and gingival health between bioflx and zirconia crowns The study will also assess the clinical performance of both types of crowns in terms of bacterial adhesion , child and parents satisfaction,as well as preparation time.
Detailed description
Dental caries is an oral disease most ubiquitous among children, characterized by a series of demineralization and remineralization cycles. If left untreated, it can progress to cavitated lesions. Usually, the familiar method of managing multi-surface carious lesions in primary teeth with stainless steel crowns .Streptococcus mutans is considered to be the main colonizer and primary etiological factor in caries progression as it stimulates the production of glucans from the food substrates. Research has indicated that S. mutans can be isolated from plaque samples. Consequently the long-term success of a restored tooth is significantly affected by the adhesion of S. mutans to the preformed crowns.Bacterial adhesion on zirconia are sparse. An in vitro study reported the initial bacterial adhesion on the surface of zirconia to be less compared with resins. When a primary tooth is restored with a full-coverage restoration, it establishes a fresh environment conducive to microbial adhesion. Bioflx Crowns the first flexible, durable, and esthetic preformedcrown for primary molars .BFCs are monochromatic, metal-free, tooth-colored crowns used in the medical device industry having high strength, flexibility, and durability. These crowns are autoclavable and are similar to SSC in tooth preparation. Additionally, they offer a cost benefit compared to zircon crowns,
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, care provider)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Bioflex crowns | Experimental | Other: (Group A: Bioflx crowns)Bioflx Crowns (BFCs) the first flexible, durable, and esthetic preformedcrown for primary molars .BFCs are monochromatic, metal-free, tooth-colored crowns used in the medical device industry having high strength, flexibility, and durability. These crowns are autoclavable and are similar to SSC in tooth preparation. Additionally, they offer a cost benefit compared to zircon crowns |
| Zirconia crowns | Experimental | Other: (Group B) : Preformed Zirconia crownzirconia crowns are frequently chosen as a comparator due to their established clinical performance and favorable biological properties. Studies have demonstrated that zirconia crowns exhibit lower bacterial adhesion, particularly of Streptococcus mutans, compared to stainless steel crowns (SSCs). highly polished and smooth surface of zirconia, which minimizes plaque accumulation and subsequent gingival inflammation. |
Who may qualify
- Ages
- 4 to 8 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (4 listed)
- patients aged 4-8 years.
- decayed in primary molars require full-coverage crowns.
- No history of systemic diseases affecting oral health.
- Cooperative children.
Key exclusion criteria (1 listed)
- -patients with severe medical conditions, badly decayed in primary molars and trauma.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| (Group A: Bioflx crowns)Minimal preparation will be required due to their flexural adaptability:1. Choose an appropriately sized Bioflex (Nusmile) crown of similar size to the mesiodistal width.2. The tooth will be prepared using a flame stone for occlusal reduction by 1-1.5 mm, including the central groove .3Proximal preparation will be around 0.5 mm, by using a fine, long, tapered diamond stone to cut interproximal slices mesially and distally.4. The crown will be placed with a snug fit and cemented using glass ionomer | Other | Bioflex crowns |
| (Group B) : Preformed Zirconia crown1. Size Determination can be achieved by holding a crown up to the existing tooth or, if available, using digital x-ray measurements to match the patient's interproximal width to the corresponding crown size.2. OcclusalPerform an occlusal reduction of about 1.5-2 mm, ensuring adequate space for the crown material. 3. Axial ReductionReduce the buccal and lingual surfaces uniformly, ensuring the removal of any prominent buccal bulges to allow for a passive crown fit. 4. Interproximal ReductionClearance: Ensure sufficient interproximal space by removing enough tooth structure to allow the crown to seat without interference.5. Subgingival PreparationMargin Placement: Extend the preparation subgingivally by approximately 2 mm to achieve optimal crown retention and aesthetics. This involves removing the chamfer margin at the tissue level and ensuring a smooth transition from the root to the coronal tooth structure | Other | Zirconia crowns |
Primary outcome
Gingival Health
Time frame: 6 months
plaque index using Silness\& Löe plaque index:0 - 3 0: no plaque.1: film at gingival margin.2: moderate accumulation.3: abundance of plaque.
Gingival health
Time frame: 6 months
Gingival index using Löe\& Silness :0 - 3 0: healthy gum.1: mild discoloration and edematous gingiva, no bleeding on probing.2: red oedematous and shiny gingiva,bleeding on probing.3: red oedematous and ulceration gingiva, spontaneous bleeding.
3 secondary outcomes
Bacterial adhesion
Time frame: 2 weeks
child and parental satisfaction
Time frame: 6 months
Preparation time
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Apr 2025.
- Background: PubMed 38616425Patil AS, Jain M, Choubey S, Patil M, Chunawala Y. Comparative evaluation of clinical success of Stainless Steel and Bioflx crowns in primary molar - A 12 month split mouth prospective randomized clinical trial. J Indian Soc Pedod Prev Dent. 2024 Jan 1;42(1):37-45. doi: 10.4103/JISPPD.JISPPD_484_23. Epub 2024 Apr 15.
- Background: PubMed 23263423Bin AlShaibah WM, El-Shehaby FA, El-Dokky NA, Reda AR. Comparative study on the microbial adhesion to preveneered and stainless steel crowns. J Indian Soc Pedod Prev Dent. 2012 Jul-Sep;30(3):206-11. doi: 10.4103/0970-4388.105012.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Manal Ahmed Elsheikh, PHD study director
Cairo University
Shaimaa Mohamed Sabry mostafa, PHD study director
Cairo University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing (Group A: Bioflx crowns) and (Group B) : Preformed Zirconia crown in people with Carious Primary Molars, run by Cairo University at 1 site in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 22 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Salma Ahmed Abdelrazig, Master degree (00201022584032, Salma.abdelrazig@dentistry.cu.edu.eg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gingival Health (time frame: 6 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06933927, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Apr 2025.