Evaluating the Performance and Efficiency of Zirconia Crowns in Treating Primary Teeth

Study Overview
=================
Brief Summary
-----------------
This randomized clinical trial aims to compare the clinical outcomes of two full-coronal-coverage restorations (locally-made preformed Zirconia crowns [LMP] and NuSmile Zirconia crowns [Nu/ZR]) in treating carious primary teeth. Amongst the children attending the clinics of the Dental School at Damascus University, the ones having an indication for crowns restorations will be screened and if they are conformant to the inclusion criteria then they will be recruited until 60 teeth are reached (30 teeth for LMP/ZR restorations and 30 for Nu/ZR restorations).

Detailed Description
-----------------
This randomized clinical trial compares the clinical outcomes of using two full-coronal zirconia restorations (locally-made preformed zirconia crowns, and NuSmile zirconia crowns) in treating carious primary teeth. Children attending to the clinics of the Faculty of Dentistry - Damascus University and who happen to be in need for dental restorations will be screened for the study's inclusion criteria till 60 teeth are recruited (30 teeth for locally made preformed zirconia crowns restorations and 30 for NuSmile zirconia crowns restorations). One crown only will be used for each patient (totally 60 patients) to ensure equalizing the variables for both groups. The randomization will be done using SPSS software version 20.0 (Armonk, NY; IBM Corp., USA). The study is going to be a double-blinded study (Patients blinding and Outcomes-assessor blinding). Simple descriptive statistics will be used for the analysis, also using Wilcoxon Signed-Rank test. The level of significance will be set at (α = 0.05) and the level of confidence at (95%). The intervention is preparing primary molars which have one or more indications for crowning, and according to manufacturer instructions. Then following up the treated primary molars for 1 month, 3 months, and 6 months intervals. The main goals are measuring and comparing the status of the gingiva and any improvements in the gingival health relative to the intervention, the plaque retention in regard to the gingival response to the material of restoration, and also the crowns resistance to changes, despite its high cost.

Official Title
-----------------
Evaluating the Performance and Efficiency of Zirconia Crowns in Treating Primary Teeth

Conditions
-----------------
Primary Teeth

Intervention / Treatment
-----------------
* Device: Locally Made Zirconia Crowns
* Device: ZR Zirconia Crwons NuSmile ® Crowns


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients within the age group of 4 to 8 years of age. Patients with good oral hygiene. Healthy children, i.e. free of any systematic diseases or any developmental disturbances of the teeth and jaws A minimal of two surfaces of caries in the targeted tooth Corresponding treated teeth has not got any crown earlier Patients with ECC as defined by the American Academy for Pediatric Dentistry. Cooperative patients who have a dental behavioral assessment of definitely positive according to Frankl behavior classification scale. Exclusion Criteria: No patient is excluded by gender, race, or due to socio-economic backgrounds.

Ages Eligible for Study
-----------------
Minimum Age: 5 Years
Maximum Age: 5 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Locally Made Zirconia Crowns<br>One operator completes all the teeth preparing and restoring procedures. Local anesthesia is achieved using Lidocaine Hydrochloride 2% with Epinephrine 1:100,000. The teeth are then isolated using a rubber dam. After caries excavation, the teeth are prepared according to manufacturer instructions. | Device: Locally Made Zirconia Crowns<br>* Occlusal reduction by decreasing the occlusal surface to less than the natural occlusal profile by about 1-1.5 mm roughly. Proximal reduction by unfastening the interproximal contacts. The tooth should be trimmed down circumferentially by around 0.5-1.25 mm as needed. Subgingival reduction, leaving no undercuts or subgingival ridges, about 1-2 mm subgingivally on every area should be prepared. Completion of the preparation by eliminating sharp lines and pointed angles to allow all prepared areas to be marginally rounded and smoothed. Locally Made Zirconia Crowns are fixed using Glass Ionomer cement (Fuji- Jaban).<br>|
| Experimental: ZR Zirconia Crwons NuSmile ® Crowns<br>One operator completes all the teeth preparing and restoring procedures. Local anesthesia is achieved using Lidocaine Hydrochloride 2% with Epinephrine 1:100,000. The teeth are then isolated using a rubber dam. After caries excavation, the teeth are prepared according to manufacturer instructions. (Same as Arm 1 Description) | Device: ZR Zirconia Crwons NuSmile ® Crowns<br>* Occlusal reduction by decreasing the occlusal surface to less than the natural occlusal profile by about 1-1.5 mm roughly. Proximal reduction by unfastening the interproximal contacts. The tooth should be trimmed down circumferentially by around 0.5-1.25 mm as needed. Subgingival reduction, leaving no undercuts or subgingival ridges, about 1-2 mm subgingivally on every area should be prepared. Completion of the preparation by eliminating sharp lines and pointed angles to allow all prepared areas to be marginally rounded and smoothed. ZR Zirconia Crwons NuSmile ® Crowns are fixed using Glass Ionomer cement (Fuji- Jaban).<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of crowns integrity | Crowns integrity changes will be measured with the naked eye and the light cure device. The scores are as follows: (0 = No crack, No fracture, No chip) (1 = Chip) (2 = Crack) (3 = Fracture). (Cvar and Rygp 2005) | Evaluating after 1 month, 3 months, 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of gingival index | is measured by passing the periodontal probe tip gently within the sulcus around each crowned tooth. The scores are as follows: (0 = normal gingiva) (1= mild inflammation) (2 = Moderate inflammation) (3 = severe inflammation). (Loe and Silness 1963) | Evaluating after 1 month, 3 months, 6 months | 
| Changes of crown marginal adaptation | Crown marginal adaptation will be measured at the buccal and lingual walls and will be referred to as either good for crowns with sealed margins or poor when the explorer detects an open margin. (Farsi and Sharaf 2004) | Evaluating after 1 month, 3 months, 6 months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Primary posterior teeth, zirconia crown