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Completed

NCT Number: NCT06847646

Evaluation of Bioflex Crowns Using the Hall Technique in Primary Molars

The goal of this randomized controlled clinical trial is to to evaluate the clinical performance and radiographic success of BioFlex crowns versus SSCs using Hall Technique in primary dentition. The main questions it aims to answer are:

Does bioflex crowns have the same clinical performance and radiographic success of stainless steel crowns when placed using Hall Technique?

will bioflex crowns alter the occlusal vertical dimensions or affect the tempomandibular joint?

If there is a comparison group: Researchers will compare bioflex crown to stainless steel crown to see of the bioflex crowns are effective as stainless steel crowns when placed using hall technique

Participants will recieve bioflex crown and stainless steel crown according to randomization and they will be followed up immediately after treatment, after 2 weeks , after 1 months , after 3 months , after 6 months and after 12 months

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Key information

Conditions

BioFlex Crowns Using Hall Technique

Age range

4 year–7 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Faculty of Dentistry Alexandria University

Alexandria, Egypt

About this study

The study will be a double-armed randomized controlled clinical trial, with parallel design. A total of 74 pediatric patients aged 4-8 years will be selected from the Pediatric Dentistry Outpatient Clinic, Faculty of Dentistry, Alexandria University, Egypt. Participants will be allocated into 2 groups according to the type of crown used. Group I (study group) will be treated with BioFlex crowns using Hall technique, while Group II (control group) will be treated with the SSCs using Hall technique. Clinical and radiographic success of both crowns will be assessed. The function of the temporomandibular joint (TMJ) will be evaluated using the Helkimo Clinical Dysfunction Index (Di) and the AAPD questionnaire. The Occlusovertical dimension measurements will also be evaluated using the Van der Zee and Van Amerongen method. Plaque and gingival health will be recorded using plaque and gingival indices, and the satisfaction level of the child will be assessed using the Facial Image Scale (FIS), while the satisfaction level of parents will be assessed using questionnaire.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Primary molar teeth with occlusal or occlusoproximal carious lesions into dentin (ICDAS codes: 3-5).

Exclusion criteria

Teeth will be excluded if they exhibit:

  • Clinical or radiographic signs of irreversible pulpitis.
  • Presence of fistula or abscess.
  • Spontaneous pain.
  • Pulp exposure.
  • Bruxism.
  • Pathologic mobility (identified by gently rocking the tooth buccolingually using tweezers).

Treatment and study plan

bioflex crown using hall technique

Other

crowns assessment

stainless steel crown using hall technique

Other

crown assessment

Primary outcomes

  1. To evaluate the clinical performance of BioFlex crowns versus SSCs using HT.

    Time frame: 12 months

    clinical evaluation of crown performance

    Success:

    • Satisfactory restoration/crown, no intervention required
    • No clinical signs or symptoms of pulp pathology

    Minor Failures:

    • Crown presents perforation
    • Crown loss - tooth able to be re-treated

    Major Failures:

    • Reversible or irreversible pulpitis or dental fistula/abscess, requiring pulpotomy, pulpectomy or extraction.

  2. To evaluate the radiographic success of BioFlex crowns versus SSCs using HT.

    Time frame: 12 months

    radiographic evaluation using digital xrays

    • Teeth will be considered radiographically successful if they show no evidence of:
    • Radicular radiolucency
    • Internal or external root resorption
    • Periodontal ligament space widening

Secondary outcomes

  1. Temporomandibular joint function assessment

    Time frame: 6 months

    The Helkimo Clinical Dysfunction Index (modified version) assesses TMJ dysfunction based on:

    Maximum Opening:

    0 = ≥35 mm

    • = 25-34 mm
    • = <25 mm

    Deflection During Opening:

    0 = <2 mm

    • = 2-5 mm
    • = >5 mm

    Impaired TMJ Function:

    0 = no impairment

    • = palpable click
    • = audible click, deadlock, or luxation

    Pain in TMJ:

    0 = no pain

    • = palpable pain
    • = reflex pain

    Muscle Pain (Temporalis & Masseter):

    0 = no pain

    • = palpable pain
    • = reflex pain

    Score Classification:

    0 = no dysfunction 1-4 = mild dysfunction 5-9 = moderate dysfunction 9 = serious dysfunction

    The AAPD guidelines are used for assessing TMJ symptoms, asking about difficulty opening the mouth, pain, muscle pain in the temporalis and masseter, sounds, and jaw-related injuries. Responses are yes/no.

  2. Changes in the occlusal vertical dimensions

    Time frame: 1 month

    The assessment of the OVD will be performed according to a Modified version of van der Zee and van Amerongen method The cusp tip of the left maxillary canine was marked using a pencil on the lower canine in the maximum intercuspation, and its distance to the mandibular canine cusp tip was measured using a UNC-15 probe and used as the overbite score

  3. Dental plaque assessment

    Time frame: 12 months

    Criteria for scoring plaque index (Silness and Löe)

    0 No plaque

    • A film of plaque adhering to the free gingival margin and adjacent area of the tooth. The plaque may only be recognized by running a probe across the tooth surface.
    • Moderate accumulation of soft deposits within the gingival pockets or the tooth and gingival margin which can be seen with the naked eye.
    • Abundance of soft matter within the gingival pocket and /or on the tooth and gingival margin.

  4. gingival health assessment

    Time frame: 12 months

    Criteria for scoring gingival index (Löe and Silness) 0 Healthy (No gingivitis.).

    • Mild gingivitis, Slight redness and edema, no bleeding upon probing
    • Moderate gingivitis, moderate redness and edema, bleeding upon probing
    • Severe gingivitis, severe redness and edema, spontaneous bleeding and ulcerations

  5. Parental satisfaction assessment

    Time frame: 12 months

    • The satisfaction level of parent/legal guardian will be assessed as performed immediately post-operative, in addition to problems that the child might be facing, such as bleeding around the crown, sensitivity, and food lodgment using questionnaire Parental satisfaction will be assessed on a Likert type scale from 1 to 5 using the seven following variables: shade, size, shape, retention, durability, overall satisfaction, and child's satisfaction.

  6. child satisfaction assessment

    Time frame: immediately after treatment

    • The patient's perception of the treatment will be assessed by using the Facial Image Scale (FIS) modified from the Maunuksela et al scale
    • Very happy.
    • Happy.
    • Neutral.
    • Sad.
    • Very sad.

Sponsors and collaborators

Lead sponsor

Alexandria University

Other

Registry information

Official study title

Evaluation of Bioflex Crowns Using the Hall Technique in Primary Molars (a Randomized Controlled Clinical Trial)

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Feb 26, 2025
Registry last updated
Dec 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.