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Gingival Health After Zirconia Versus Stainless Steel Crowns in Children

Comparison of Gingival Health Outcomes Between Prefabricated Zirconia Crowns and Stainless Steel Crowns in Primary Molars: A Randomized Split-Mouth Clinical Trial

Status
Enrolling by invitation
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07436325
Enrollment
100
Registered
2026-02-27
Start date
2026-05-12
Completion date
2029-06-01
Last updated
2026-06-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Gingival Disease

Keywords

gingival health, Plaque index, Zirconia crown, Stainless steel crown

Brief summary

The goal of this clinical trial is to learn if prefabricated zirconia crowns (PZCs) improve gingival health compared to stainless steel crowns (SSCs) in primary molars of young children. It will also learn about plaque accumulation and parental satisfaction with the crowns. The main questions it aims to answer are: 1. Do PZCs lead to better gingival health than SSCs over time? 2. Do PZCs reduce plaque accumulation compared to SSCs? 3. Do parents report higher satisfaction with PZCs versus SSCs? Researchers will compare PZCs to SSCs in a split-mouth design (each child receives one of each crown type on contralateral molars) to see if PZCs provide superior gingival health, plaque control, and satisfaction. Participants will: 1. Receive PZCs on one primary molar and SSCs on the contralateral molar after tooth preparation 2. Attend follow-up visits at 12, 24, and 36 months for gingival health and plaque assessments 3. Complete parental satisfaction surveys at each follow-up visit

Detailed description

This clinical trial is a prospective, randomized, split-mouth controlled study designed to compare the long-term effects of prefabricated zirconia crowns (PZCs) and stainless steel crowns (SSCs) on gingival health, plaque accumulation, and parental satisfaction in primary molars of young children. The study addresses the need for evidence on how these restorative materials influence periodontal outcomes, given the conflicting data in existing literature regarding their biocompatibility, esthetics, and impact on gingival tissues. SSCs have been the standard for durability and cost-effectiveness in pediatric dentistry, but their metallic appearance and potential for plaque retention due to marginal microgaps raise concerns for esthetics and gingival inflammation. PZCs, offering superior esthetics and a polished surface, may provide advantages in reducing plaque adherence and improving mucosal compatibility, though long-term comparative data are limited. This trial will employ a split-mouth design at the Pediatric Dental Clinic of Qassim University, Buraydah, Al-Qassim Province, Saudi Arabia. This intra-subject approach minimizes inter-individual variability in factors such as salivary composition, microbial ecology, brushing habits, dietary sugar intake, and systemic health, enabling direct comparison of the two crown types within the same child. One hundred healthy children with bilateral primary molars requiring full-coverage restorations will be enrolled. Randomization using a computer-generated sequence with allocation concealment via opaque envelopes opened chairside post-preparation will be implemented. Contralateral molars will receive either a PZC or SSC (randomly assigned), ensuring balanced distribution. Tooth preparation will be standardized under local anesthesia (2% lidocaine with 1:100,000 epinephrine): pulpotomy/pulpectomy as indicated, circumferential reduction (1-1.5 mm) with tapered diamond burs, occlusal clearance (1.5-2 mm), and proximal adjustments. PZCs will be fitted without crimping for optimal marginal adaptation (\<50 μm target), while SSCs will undergo mechanical crimping for tight cervical fit (\<30 μm discrepancy). Both will be luted with resin-modified glass ionomer cement (RelyX™ Luting Plus, 3M™) for fluoride release and reliable bonding. Assessments will be conducted by two independent, calibrated examiners (inter-rater kappa \>0.80) blinded to crown type via opaque cheek retractors.

Interventions

Prefabricated zirconia crown (NuSmile® ZR) placed on primary molar after standardized preparation (1-1.5 mm circumferential reduction, 1.5-2 mm occlusal clearance); cemented with resin-modified glass ionomer (RelyX™ Luting Plus, 3M™).

Stainless steel crown (3M™ ESPE™) placed on contralateral primary molar after identical preparation; crown crimped at margins for adaptation; cemented with resin-modified glass ionomer (RelyX™ Luting Plus, 3M™)

Sponsors

Murad Alrashidi
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Intervention model description

Split Mouth Design

Eligibility

Sex/Gender
ALL
Age
3 Years to 7 Years
Healthy volunteers
Yes

Inclusion criteria

1. Healthy children aged 3-7 years. 2. Bilateral primary molars requiring full-coverage restorations. 3. Adequate tooth structure (\>50% remaining post-preparation).

Exclusion criteria

1. Children with moderate to severe baseline plaque accumulation (Silness \& Löe Plaque Index ≥2) or parents/caregivers reporting inconsistent brushing (\<2x/day). 2. Children with excessive sugar intake (\>3 sugary snacks/beverages daily), assessed via the Beverage and Snack Questionnaire. 3. Systemic diseases affecting oral health (e.g., immunocompromised status, diabetes mellitus). 4. Active periodontal disease or severe malocclusion. 5. Allergy to crown materials.

Design outcomes

Primary

MeasureTime frameDescription
Change in Gingival HealthBaseline, 12 months, 24 months, and 36 monthsGingival health assessed using the Löe Gingival Index. Four sites per tooth (mesial, distal, buccal, lingual) are scored as follows: 0 = Normal gingiva (no inflammation) 1. = Mild inflammation - slight change in color, slight edema, no bleeding on probing 2. = Moderate inflammation - redness, edema, glazing, bleeding on probing 3. = Severe inflammation - marked redness and edema, ulceration, tendency to spontaneous bleeding Mean score per tooth (or per participant across assessed sites) is calculated. Higher scores indicate worse gingival inflammation. This primary outcome evaluates the comparative effect of prefabricated zirconia crowns versus stainless steel crowns on gingival tissue response over time, with assessments performed by blinded calibrated examiners.

Secondary

MeasureTime frameDescription
Plaque Index ScoreBaseline, 12 months, 24 months, and 36 monthsPlaque accumulation assessed using the Silness \& Löe Plaque Index. Four sites per tooth (mesial, distal, buccal, lingual) are scored as follows: 0 = No plaque in the gingival area 1. = A thin film of plaque adhering to the free gingival margin and adjacent area of the tooth; plaque recognized only by running a probe across the tooth surface 2. = Moderate accumulation of soft deposits within the gingival margin or adjacent tooth surface, visible to the naked eye 3. = Abundance of soft matter within the gingival pocket and/or on the tooth and gingival margin Mean score per tooth (or per participant across assessed sites) is calculated. Higher scores indicate greater plaque thickness and accumulation. This outcome compares plaque control between prefabricated zirconia crowns and stainless steel crowns, evaluated by blinded calibrated examiners

Countries

Saudi Arabia

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 3, 2026