An interventional study of Cementation with Fuji IX GP Extra Glass Ionomer Cement and Cementation with BioCem™ Universal BioActive Cement in Dental Caries, Tooth Injuries and Primary Tooth Restoration, sponsored by Murad Alrashidi. Active, not recruiting at 1 site in Saudi Arabia. Open to participants aged 2 Years to 7 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-13.
Sponsored by Murad Alrashidi · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to compare the long-term clinical performance of three different luting cements used to bond prefabricated zirconia crowns (PZCs) on primary front teeth in young children. The trial will determine whether any single cement offers superior retention, gum health, or marginal sealing compared to the others over a 3-year period.
Main Questions:
The study aims to answer the following:
Are conventional glass ionomer cement (GIC), bioactive resin-modified glass ionomer cement (BioCem™), and self-adhesive resin cement (SARC) equivalent in retaining prefabricated zirconia crowns on primary incisors over 36 months? Do these cements differ in their effect on gingival health, plaque accumulation, or marginal discoloration around the cemented crown?
Comparison:
Researchers will compare three parallel groups of children whose primary incisors are restored with identical prefabricated zirconia crowns but cemented with one of the three different luting cements.
Participants will: Receive a clinical and radiographic dental examination at screening. Undergo placement of one or more prefabricated zirconia crowns on primary anterior teeth using their randomly assigned cement. Return to the clinic for blinded follow-up evaluations at 12, 24, and 36 months for assessment of crown retention, gingival health, plaque, and marginal staining.
This prospective, parallel-group, three-arm, randomized controlled trial evaluates the long-term clinical performance of three commercially available luting cements when used to bond prefabricated zirconia crowns (PZCs) on primary anterior teeth in pediatric patients. Although PZCs are increasingly preferred over stainless steel crowns for anterior restorations due to their superior esthetics and biocompatibility, their retention relies entirely on the luting cement because of their passive fit and conservative preparation design. Comparative clinical evidence on cement performance in this specific anatomical and functional context remains limited.
Trial Design:
The trial is conducted at the Pediatric Dental Clinic of Qassim University, Riyadh, Saudi Arabia. Eligible children aged 2 to 7 years requiring full-coverage restoration of one or more primary incisors are randomized in a 1:1:1 ratio to one of three cement groups using a computer-generated randomization sequence. Allocation labels are reshuffled after each assignment to preserve equal group sizes. An independent outcome assessor is blinded to group allocation throughout the trial, and standardized cheek retractors are used to mask cement margins during evaluations. Operators cannot be blinded due to material-specific application protocols.
Intervention Protocols:
Tooth preparation follows standardized anterior-specific minimal reduction principles (1.0-1.5 mm incisal, 0.5-0.8 mm uniform labial, feather-edge proximal margins) under rubber dam isolation. NuSmile® prefabricated zirconia crowns are used for all participants. Cement application follows manufacturer instructions for each group:
Group 1 (GIC): Fuji IX GP Extra (GC America) - tooth conditioned with 20% polyacrylic acid for 20 seconds, rinsed, gently air-dried; cement hand-mixed, loaded into crown, seated under finger pressure for 3 minutes.
Group 2 (BioCem™): BioCem™ Universal BioActive Cement (NuSmile®) - tooth cleaned with pumice and water, rinsed, dried; cement auto-mixed into crown, seated, briefly light-cured (2-3 s) for excess removal, then fully light-cured 20 s per surface.
Group 3 (SARC): RelyX™ Universal Resin Cement (3M) - tooth cleaned with pumice and water, rinsed, dried; cement loaded, crown seated, tack-cured 2-3 s, excess removed, full light-curing 20 s per surface.
All crowns are placed by a single calibrated pediatric dentist. Post-cementation periapical radiographs verify marginal integrity. Parents receive standardized oral hygiene instructions and a 7-day course of 0.12% chlorhexidine mouthwash.
Follow-Up and Safety:
Clinical evaluations occur at baseline, 12, 24, and 36 months. Retention is assessed by visual/tactile examination with a sharp explorer and LED transillumination (DEXIS CariVu®). Failed crowns are recemented and excluded from subsequent analyses. Adverse events including soft-tissue irritation, crown fracture, debonding, and aspiration risk are continuously recorded.
Statistical Methodology:
Sample size was calculated using G*Power 3.1.9.7 assuming a medium effect size (f = 0.25) for ANOVA, 90% power, and α = 0.05, yielding 28 participants per group; this was inflated to 40 per group (total 120) to accommodate an anticipated 30% attrition over 36 months. The primary retention outcome will be analyzed by Kaplan-Meier survival analysis with between-group comparison using the log-rank test, supplemented by Fisher's exact test for proportional retention and Cox proportional hazards regression for hazard ratios. Gingival Index and Plaque Index will be compared between groups by one-way ANOVA and within groups by repeated-measures ANOVA. Margin discoloration distribution will be compared by chi-square (with Cramér's V as effect size) and within-group transitions by McNemar's test. Significance is set at p \< 0.05. Analyses will follow an intention-to-treat principle, with per-protocol sensitivity analyses.
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 →Murad Alrashidi is the lead sponsor of 4 studies on the registry; none are open to participants now.
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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.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
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.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Glass Ionomer Cement (GIC) Group: Participants receive a NuSmile® prefabricated zirconia crown cemented with conventional glass ionomer cement (Fuji IX GP Extra, GC America) following a standardized polyacrylic-acid-conditioning protocol.
Procedure: Cementation with Fuji IX GP Extra Glass Ionomer Cement
Bioactive Resin-Modified Glass Ionomer Cement (BioCem™) Group: Participants receive an identical NuSmile® prefabricated zirconia crown cemented with BioCem™ Universal BioActive Cement (NuSmile®, Houston, TX, USA).
Procedure: Cementation with BioCem™ Universal BioActive Cement
Self-Adhesive Resin Cement (SARC) Group: Participants receive an identical NuSmile® prefabricated zirconia crown cemented with RelyX™ Universal Resin Cement (3M).
Procedure: Cementation with RelyX™ Universal Resin Cement
Cementation with Fuji IX GP Extra Glass Ionomer Cement Hand-mixed conventional glass ionomer luting cement applied per manufacturer protocol; crown seated under finger pressure for 3 minutes; excess removed after initial set.
Cementation with BioCem™ Universal BioActive Cement Auto-mixed bioactive resin-modified luting cement applied per manufacturer protocol; brief tack-cure to facilitate excess removal followed by full light-curing for 20 seconds per surface.
Cementation with RelyX™ Universal Resin Cement Self-adhesive dual-cure resin luting cement applied per manufacturer protocol; tack-cured for 2-3 seconds for excess removal, followed by full light-curing for 20 seconds per surface.
Crown Retention (Survival)
The primary outcome is the cumulative retention of prefabricated zirconia crowns over a 36-month follow-up period. Retention is assessed by a single blinded examiner at each scheduled visit using two complementary methods: (a) visual/tactile inspection with a sharp dental explorer applied circumferentially along the crown margin to detect dislodgement, mobility, or marginal gap; and (b) LED transillumination using the DEXIS CariVu® system to detect cracks, debonding, or marginal microleakage. A crown is classified as "failed" (debonded) if any complete loss of cement seal, dislodgement, or detectable marginal gap is observed. Retention is reported as the proportion of crowns surviving at each time point and as the time-to-failure for survival analysis. Higher retention proportions and longer survival times indicate better clinical performance.
Time frame: Baseline, 12, 24, and 36 months post-cementation
Plaque Accumulation Measured by the Silness & Löe Plaque Index (1964)
Plaque accumulation at the gingival margin of each cemented crown is assessed using the Silness \& Löe Plaque Index. The same four sites per tooth (mesial, distal, buccal, lingual) are scored by a blinded examiner on a 4-point ordinal scale: 0 = no plaque; 1 = a film of plaque adhering to the free gingival margin, recognizable only by running a probe across the surface; 2 = moderate accumulation of soft deposits visible to the naked eye; 3 = abundance of soft matter. A mean PI score is calculated per tooth and per participant; the participant-level mean ranges from a minimum of 0 to a maximum of 3, with higher scores indicating greater plaque accumulation.
Time frame: Baseline, 12, 24, and 36 months post-cementation
Gingival Health Measured by the Löe Gingival Index (1967)
Gingival inflammation around each cemented crown is assessed at baseline and at every follow-up visit using the Löe Gingival Index (1967). A single blinded examiner scores four gingival sites per tooth (mesial, distal, buccal, and lingual) on a 4-point ordinal scale: 0 = no clinical inflammation (normal gingiva); 1 = mild inflammation (slight color change, 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). A mean GI score is calculated per tooth and per participant; the participant-level mean therefore ranges from a minimum of 0 to a maximum of 3, with higher scores indicating worse gingival health.
Time frame: Baseline, 12, 24, and 36 months post-cementation
Marginal Discoloration Measured by the Modified United States Public Health Service (USPHS) Criteria
Discoloration at the crown-tooth interface is evaluated under standardized LED operatory lighting (1,000-1,400 lux) without magnification using the modified USPHS criteria, supplemented by high-resolution intraoral photography with cross-polarized filters. Each crown is assigned one of four ordinal ratings: Alpha (A) = no visible discoloration (best outcome); Bravo (B) = slight discoloration confined to the margin, not penetrating internally; Charlie (C) = obvious discoloration penetrating along the margin; Delta (D) = severe discoloration with secondary caries or restoration failure (worst outcome). The outcome is reported as the proportion of crowns in each category at each time point, with a higher proportion of Alpha ratings indicating better marginal integrity.
Time frame: Baseline (immediately post-cementation), 12, 24, and 36 months
Incidence and Severity of Adverse Events
The frequency, type, and severity of all adverse events occurring during the 36-month follow-up will be recorded for each arm. Events of interest include crown debonding, crown fracture, soft-tissue irritation or ulceration adjacent to the crown margin, allergic reaction to cement components, secondary caries, and pulpal complications. Severity will be classified using a three-tier framework adapted from the Common Terminology Criteria for Adverse Events (CTCAE) approach: Mild (Grade 1) - no intervention required; Moderate (Grade 2) - non-urgent intervention required (e.g., recementation at a scheduled visit); Severe (Grade 3) - urgent intervention, crown replacement, or treatment of secondary pathology required. The primary safety endpoint is the incidence rate (events per participant per year of follow-up) in each arm.
Time frame: Continuously, from cementation through 36 months
Plan to share: Yes — The investigators will share de-identified individual participant data underlying the results reported in the final publication. Shared data may include retention status at each time point, time-to-failure, Gingival Index and Plaque Index scores, USPHS marginal discoloration ratings, and adverse event records. The study protocol and statistical analysis plan will also be made available.
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Data will be available beginning 6 months and ending 36 months following article publication.
Access criteria: Data will be shared with researchers who provide a methodologically sound proposal and whose intended use has been approved by an independent review committee. Proposals should be directed to the primary investigator. To gain access, requestors must sign a data access agreement.
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Murad Alrashidi