NCT06856070

Retention of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars

Evaluation of Retention and Resistance to Dislodgement of Bioflx Crowns Compared to Zirconia Crowns on Primary Molars

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 50 (estimated)
• Sponsor: Cairo University · Academic / Other
• Sex: All
• Age: 4 Years – 8 Years
• Healthy volunteers: Accepted

Summary

The goal of this clinical trial is to evaluate the retention and resistance to dislodgment of Bioflx crowns compared to zirconia crowns in the restoration of primary molars. The main question\[s\] it aims to answer : Is there a difference in the retention and resistance to dislodgement of BioFlx crowns compared to zirconia crowns in the restoration of primary molars?" The study will also assess the clinical performance of both types of crowns in terms of occlusal wear, gingival health, preparation time, as well as child and parental satisfaction.

Detailed description

Primary molars play a significant role in maintaining oral function, esthetics, and space for permanent teeth, therefore, restoring decayed primary molars is a critical aspect of pediatric dentistry. Stainless steel crowns have been the standard restorative material for primary molars due to their clinical success, retention, and durability. However, the aesthetic limitations of SSCs, have been problematic, especially when patients seek more esthetically acceptable treatment options.In an attempt to address the aesthetic limitations of stainless-steel crowns, pre-veneered stainless-steel crowns were introduced featuring a thin layer of composite resin or ceramic on the outside to improve their appearance. While they provided a better aesthetic than pure stainless steel, their limitations included a tendency to wear down over time, difficulty in matching natural tooth color, and the potential for the veneer to chip or detach.Recently, zirconia crowns are preferred over pre-veneered stainless-steel crowns for their esthetic superiority, biocompatibility, and resistance to wear. They demonstrate excellent retention and durability but require significant tooth preparation, which may compromise tooth structure. Despite their advantages, zirconia crowns posed challenges such as increased cost, more complex preparation techniques, and concerns about their brittleness under certain conditions. Moreover, zirconia crowns may not be suitable for all cases, especially those involving less mineralized or structurally compromised primary molars .In 2021, Kids-e-Dental LLP introduced Bioflx Crowns and claimed as the first flexible, durable, and esthetic preformed crown for primary molars. Bioflx Crowns are monochromatic, metal-free, tooth-colored crowns made up of high-strength resin polymer used in the medical device industry having high strength, flexibility, and durability. These crowns are autoclavable and are like SSC in tooth preparation as claimed by the manufacturer. Their flexibility and snap-fit technology aim to improve retention while minimizing trauma during placement. It is important to mention that retention is a crucial factor for the success of any dental crown. An inadequate retention can lead to crown displacement, necessitating re-treatment, and ultimately affect the long-term health of the primary tooth. While studies have demonstrated the superior esthetic properties of materials like Bioflx crowns, their clinical performance, particularly retention rates and overall longevity, require further evaluation in direct comparison to zirconia crowns .Thus, this trial aims to fill the gap in current knowledge and provide clinicians with evidence to support the choice of crown material based on retention performance, which is critical to the long-term success of pediatric restorations.

Conditions

• Carious Primary Molars

Interventions

Type	Name	Description
OTHER	(Group A: Preformed Bioflx crown)	prepartion:1.The mesiodistal width of the tooth will be measured using calipers and a closely fitted crown will be selected based on the measurements. 2\. The tooth will be prepared similarly to stainless steel crowns (SSCs): * Occlusal reduction of approximately 1-1.5 mm will be done using a diamond bur.Mesial and distal reduction of no more than 1 mm will be performed using a No. 169L diamond bur.Depending on the tooth anatomy, either no buccal and lingual reduction will be needed, or a minimal reduction will be done. 3.All sharp line angles and corners will be smoothed to ensure proper crown fit. 4.The crown will be checked for proper fit before cementation. It will be positioned to extend 1 mm below the gingival margin. 5.The crown will be cemented using luting glass ionomer cement (GIC). The crown will be held with firm, constant pressure until the cement sets initially. 6.The marginal fit will be evaluated, and necessary adjustments will be made. 7.The occlusion will be checked,
OTHER	(Group B: Preformed Zirconia crown)	1\. Crown Selection: The mesiodistal dimension of the corresponding tooth will be measured . to select the appropriate size.2. Occlusal Reduction: The marginal ridge of adjacent teeth will be used as a reference point and a 1.5-2 mm of occlusal reduction will be performed to allow proper crown seating.3. Bucco-Lingual Reduction: The bucco-lingual wall will be reduced by approximately 1-1.5 mm using a flame-shaped diamond bur.4. Interproximal Reduction: 1 mm of interproximal reduction will be performed using a flame-shaped diamond bur such as a .368 or .330 tapered carbide bur.5. Feather Margin Preparation: Subgingival reduction of 1-2 mm will be done using a flame-shaped diamond bur, creating a feathered margin to achieve a passive fit.6. Trial Fitting of the Crown: The crown will be tried in to ensure proper adaptation. until the crown fits passively and extends sub gingivally by 1-2 mm wit.7. Glass ionomer cement will be used for cementation.

Timeline

• Start date: 2025-06-30
• Primary completion: 2025-12-01
• Completion: 2026-02-01
• First posted: 2025-03-04
• Last updated: 2025-03-04

Locations

2 sites across 1 country: Egypt