An interventional study of Zirconia Crown and Bioflx Crown in Dental Caries and Tooth Hypomineralization, sponsored by Hue University of Medicine and Pharmacy. Active, not recruiting at 1 site in Vietnam. Open to participants aged 3 Years to 5 Years. Per ClinicalTrials.gov, last updated 2026-07-09.
Sponsored by Hue University of Medicine and Pharmacy · Not applicable, Interventional, and Treatment
This parallel-group randomized controlled trial will compare the clinical performance of prefabricated zirconia and Bioflx crowns for restoring primary maxillary anterior teeth in children aged 3 to 5 years. Eligible participants will be randomly assigned in a 1:1 ratio to receive either a zirconia crown or a Bioflx crown.
Clinical outcomes will be assessed at 3, 6, and 12 months after crown placement. Evaluations will include gingival health, plaque accumulation, wear of the opposing tooth, crown retention, and clinical symptoms of the treated tooth. Parent satisfaction with the esthetic outcome will also be evaluated.
The study aims to provide comparative clinical evidence on the effectiveness of zirconia and Bioflx crowns for restoration of primary maxillary anterior teeth.
Primary maxillary anterior teeth are important for esthetics, speech, mastication, and maintenance of normal oral function in young children. Extensive caries and hypomineralization may result in substantial loss of tooth structure and require full-coverage restoration. Prefabricated zirconia and Bioflx crowns are esthetic restorative options; however, comparative clinical evidence for their use in primary maxillary anterior teeth remains limited.
This study is a parallel-group randomized controlled clinical trial conducted in children aged 3 to 5 years who require full-coverage restoration of primary maxillary anterior teeth. Eligible participants must have an opposing tooth and at least two carious surfaces on the target tooth, caries involving the incisal edge, or discoloration associated with hypomineralization. Children with acute systemic disease, allergy to the luting cement, pulp exposure before treatment, inadequate remaining tooth structure, severe bruxism or deep bite, advanced root resorption, previous trauma affecting the target tooth, or other predefined exclusion criteria will not be enrolled.
A minimum of 120 teeth will be included. Randomization will be performed at the participant level using a computer-generated variable block sequence with a 1:1 allocation ratio. Allocation concealment will be maintained using sequentially numbered opaque sealed envelopes.
Participants will receive either prefabricated zirconia crowns or prefabricated Bioflx crowns. Clinical and radiographic examinations will be completed before treatment. Crown preparation and cementation procedures will be standardized, and Fuji IX Extra glass ionomer cement will be used for crown placement.
The primary outcome will be gingival health at 6 months after crown placement. Secondary outcomes will include plaque accumulation, wear of opposing teeth, crown retention, clinical symptoms of crowned teeth, and parent satisfaction with crown esthetics. Follow-up assessments will be performed at 3, 6, and 12 months. Statistical analyses will account for clustering when more than one tooth is included from the same participant.
1,171 studies on the registry are indexed under Dental Caries; 209 are open to participants now.
This study's planned enrollment of 120 is above the median of 60 across 967 interventional studies indexed under Dental Caries.
Browse Dental Caries studies →Hue University of Medicine and Pharmacy is the lead sponsor of 13 studies on the registry; 1 is open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive prefabricated zirconia crowns for restoration of indicated primary maxillary anterior teeth. Teeth are prepared using a standardized clinical protocol, and crowns are cemented with Fuji IX Extra glass ionomer cement.
Other: Zirconia Crown
Participants receive prefabricated Bioflx crowns for restoration of indicated primary maxillary anterior teeth. Teeth are prepared using a standardized clinical protocol, and crowns are cemented with Fuji IX Extra glass ionomer cement.
Other: Bioflx Crown
Prefabricated zirconia crowns manufactured by Shinhung, Republic of Korea, will be used to restore eligible primary maxillary anterior teeth. Tooth preparation, crown selection, cementation with Fuji IX Extra glass ionomer cement, removal of excess cement, and post-treatment instructions will follow a standardized protocol.
Prefabricated Bioflx crowns manufactured by Kids-e-Dental, India, will be used to restore eligible primary maxillary anterior teeth. Tooth preparation, crown selection, cementation with Fuji IX Extra glass ionomer cement, removal of excess cement, and post-treatment instructions will follow a standardized protocol.
Gingival index
Gingival status adjacent to crowned primary maxillary anterior teeth, assessed using the Löe and Silness Gingival Index. Lower scores indicate better gingival health.
Time frame: 3, 6, and 12 months after crown placement
Fluorescent Plaque Index
Plaque accumulation on crowned primary maxillary anterior teeth, assessed using QrayScan Plus according to the Fluorescent Plaque Index (FPI; 0-5). Higher scores indicate greater plaque accumulation.
Time frame: 3, 6, and 12 months after crown placement
Opposing Tooth Wear
Wear of the tooth opposing the crowned primary maxillary anterior tooth, assessed clinically on a 0-4 ordinal scale. Higher scores indicate greater enamel and dentin loss.
Time frame: 3, 6, and 12 months after crown placement
Crown Retention
Retention status of the prefabricated crown, categorized as retained or loose/lost.
Time frame: 3, 6, and 12 months after crown placement
Clinical Status of Crowned Teeth
Clinical status of teeth restored with prefabricated crowns, categorized as asymptomatic, sensitive, mobile, painful, or swollen.
Time frame: 3, 6, and 12 months after crown placement
Parental Satisfaction
Parental satisfaction with the esthetic outcome of crown restoration, assessed using a 4-point Likert scale for crown shape, color, alignment, interdental spacing, perceived crowding, and other esthetic abnormalities. Lower scores indicate greater satisfaction.
Time frame: 6 and 12 months after crown placement
Plan to share: No
Started Jan 2026 (actual). Primary completion is estimated for Apr 2027, 15 months after the start.
Of 469 non-industry interventional studies with no phase under Dental Caries, half reached primary completion within 15 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 30. This study's planned 15 months is close to that.
Counting every sponsor, half of 502 studies reached it within 15 months; a quarter within 7 and three quarters within 29.
How these figures are worked out, and which studies are left out of them.
This study is active, not recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Hue University of Medicine and Pharmacy