An interventional study of (Group A: Bioflx crowns) and (Group B) : Preformed Zirconia crown in Carious Primary Molars, sponsored by Cairo University. Not yet recruiting at 1 site in Egypt. Open to participants aged 4 Years to 8 Years. Per ClinicalTrials.gov, last updated 2025-04-22.
Sponsored by Cairo University · Not applicable, Interventional, and Treatment
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.
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,
241 studies on the registry are indexed under Tissue Adhesions; 29 are open to participants now.
This study's planned enrollment of 28 is below the median of 60 across 184 interventional studies indexed under Tissue Adhesions.
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Exclusion Criteria:
-patients with severe medical conditions, badly decayed in primary molars and trauma.
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
Other: (Group A: Bioflx crowns)
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.
Other: (Group B) : Preformed Zirconia crown
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
1. 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
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.
Time frame: 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.
Time frame: 6 months
Bacterial adhesion
Method of measurement : by( Mitis salivarius agar) Unit of measurement :Colony-formingunits.
Time frame: 2 weeks
child and parental satisfaction
5-Point likert's scale / Questionnaire. 1. Very Happy.2. Happy.3. Neither.4. Unhappy.5. Very Unhappy.
Time frame: 6 months
Preparation time
Method of measurement : stop watch Unit of measurement : minutes
Time frame: 6 months
This study is not yet recruiting, as verified in Apr 2025. You cannot join it, but the record below documents what was studied.
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Cairo University