Abstract
BackgroundAfter root canal treatment, most tooth defects need to be restored. Onlay restoration is widely used to restore dental defects. Endocrown is a new type of onlay; however, dentists have yet to obtain a full understanding of the clinical effects of marginal forms of endocrowns. Here, we present a multicenter protocol to compare the clinical efficacy of two marginal forms (flat and 90-degree shoulder) for tooth restoration. The efficacy will be evaluated by marginal fit, marginal discoloration, and integrity of restoration.MethodsThe proposed flat and 90-degree shoulder marginal endocrown assessment trial is an open-label, parallel-group, multicenter randomized controlled trial involving two hospitals. A total of 200 patients will be included in this trial, and the following patient inclusion criteria will be applied: good oral hygiene habits, no periodontal diseases, receipt of standard root canal treatment, and need for endocrown restoration. Patients will be enrolled after providing signed informed consent and will be divided into two groups (flat and 90-degree shoulder endocrown) in accordance with a random number table. Treatment allocation will be balanced (1:1). Endocrowns will be cemented by dual-cured luting composite. Clinical evaluations will be performed at baseline and at 24 months after treatment in accordance with modified US Public Health Service criteria by two independent evaluators. The primary outcome will be marginal fit; secondary outcome measures will include debonding, marginal discoloration, and integrity of restoration. All acquired data will be analyzed by an independent statistician. Wilcoxon one-sample tests will be used for intra-group comparisons, and Wilcoxon two-sample tests will be used for inter-group comparisons. The Bonferroni method will be used to correct for multiple comparisons, and hierarchical logistic regression will be applied to determine central effects.DiscussionThe results of this trial will provide a clinical basis for clinicians to restore teeth by endocrowns and to improve long-term restoration for patients.Trial registrationClinicalTrials.gov identifier: NCT03398395. Registered on 12 January 2018.
Highlights
After root canal treatment, most tooth defects need to be restored
The enamel layer distribution of the teeth bases, which determines the composition of the bonding surface as well as the residual amount of dental tissue, varies according to the preparation of the different marginal forms of endocrowns
This trial will help clinicians provide their clients with evidence-based options regarding marginal forms of endocrowns
Summary
This is a multicenter, randomized, open-label superiority trial with two balanced parallel arms. 1. The patient is healthy and is 18–60 years old and has molar teeth and tooth root apex without evident damage and no root fracture, as determined by x-ray. 2. The patient has three or four walls of intact tooth tissue after complete root canal therapy. 3. The patient has good oral hygiene. 4. The patient has signed an informed consent form. 5. The patient is not participating in any other clinical trial. 6. The patient has received a class A assessment according to the modified US Public Health Service (USPHS) criteria for marginal adaptation after restoration
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
