Clinical Evaluation of Subgingival Open Sandwich Restorations

Study Overview
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Brief Summary
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This study was designed to evaluate and compare the 3-year periodontal responses and clinical performance of proximal subgingival open sandwich restorations using three different glass ionomer-based restorative materials and flowable composite.

Detailed Description
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The description of the experimental design followed the Consolidated Standards of Reporting Trials (CONSORT) statement. The present study was a double-blinded (patients and examiner) randomized clinical trial anticipating the parallel design. Ninety-five adult patients seeking dental treatment in the Operative Department clinic at the Faculty of Dentistry, University of Mansoura were enrolled in the current study with a total of 120 Class II restorations. No advertisement was made for participant recruitment, forming a sample of convenience. Each patient must signs a consent form before participating in the current study. The study was conducted from January 2020 to January 2023 as a part of the Doctoral dissertation. Mansoura University institution's ethics committee approved the form and protocol before conducting the study. The sample size was calculated based on the clinical success rate (100% success rate at 2 years) of posterior class II restorations restored with open sandwich and deep margin elevation techniques observed in previous studies. According to several parameters including a significance level of 5%, the power of the test was calculated to be 80%, and equivalent limit of 15%. Upon these data, a sample size of 120 subjects was appropriate to allow for a 20% drop-out.

Official Title
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Clinical Evaluation of Subgingival Open Sandwich Restorations: 3-year Results of a Randomized Double-blind Trial

Conditions
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Dental Restoration Failure of Marginal Integrity

Intervention / Treatment
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* Other: Proximal box elevation using one of the tested materials


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with one proximal sub gingival carious lesion ICDAS 4, or 5 in posterior teeth Patients must have a good oral hygiene; Patients with tooth gives positive response to testing with an electric pulp tester Patients with normal and full occlusion, Patients with opposing teeth should be natural with no restorations. Exclusion Criteria: High caries risk patients with extremely poor oral hygiene, Patients involved in orthodontic treatment or periodontal surgery, Patients with periodontally involved teeth (chronic periodontitis) Patients with abutments should be excluded. Patients with heavy bruxism habits and clenching

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Each patient received one or two restorations in a posterior tooth on any side randomly selected from the 4 tested restorative materials, all materials were used according to manufacturers' instructions
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Resin modified glass ionomer<br>Group received proximal box elevation using resin modified glass ionomer | Other: Proximal box elevation using one of the tested materials<br>* Each patient randomly received deep proximal margin elevation with one of the tested restorative materials, while the overlying restorations were all the same regular bulk fill resin composite<br>|
| Placebo Comparator: Glass hybrid<br>Group received proximal box elevation using glass hybrid | Other: Proximal box elevation using one of the tested materials<br>* Each patient randomly received deep proximal margin elevation with one of the tested restorative materials, while the overlying restorations were all the same regular bulk fill resin composite<br>|
| Active Comparator: Bulk fill flowable resin composite<br>Group received proximal box elevation using bulk fill flowable resin composite | Other: Proximal box elevation using one of the tested materials<br>* Each patient randomly received deep proximal margin elevation with one of the tested restorative materials, while the overlying restorations were all the same regular bulk fill resin composite<br>|
| Placebo Comparator: Ion-releasing material<br>Group received proximal box elevation using ion-releasing material | Other: Proximal box elevation using one of the tested materials<br>* Each patient randomly received deep proximal margin elevation with one of the tested restorative materials, while the overlying restorations were all the same regular bulk fill resin composite<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of patients with periodontal problems | The periodontal situation of patients were examined based on bleeding on probing, plaque index and probing depth scores | 3 years after restoration | 
| Percentage of aesthetic, functional and biological properties for each base material restorations | Percentage of aesthetic, functional and biological properties were clinically assessed using World Dental Federation parameters for each base material group | 3 years after restoration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radiographic examination | Each base material/gingival dentin interface was examined radiographically each 6 months period. | 3 years after restoration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Deep margin elevation, Proximal box elevation, Open sandwich technique, Bi-layered restorations, Subgingival cervical margin