Evaluation of Resin Composite Posterior Restorations Using Modeling Resin Insertion Technique in Class I Lesions

Study Overview
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Brief Summary
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Evaluation of Resin Composite Posterior Restorations Using Modeling Resin Insertion Technique versus Conventional Composite Placement Technique in Class I Lesions: Randomized Clinical Trial

Detailed Description
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Statement of the problem In a restorative procedure, an important objective is to obtain restorations with smooth surfaces. Surface roughness has a major influence on plaque accumulation, secondary caries, and gingival irritation. Further, it may directly influence wear behavior and the marginal integrity of composite restorations. A roughened surface of a resin composite restoration is also likely to be stained by exogenous sources, such as coffee, tea, or red wine, leading to the discoloration of the material. One of the main drawbacks of sculpting composite restorations is that some materials are sticky, reducing the ease of handling and insertion of the material into the tooth cavity. Some materials readily adhere to the composite instruments; thus, limiting reestablishment of the shape and anatomical contour of the tooth. As a result, the application of lubricants on the composite instrument such as modeling liquids/resins between the layers of composite have been proposed. Rationale Modeling resins can be directly applied between the layers using a brush or can be used as a lubricant on manual instruments. In both the aforementioned techniques, the ease of instrumentation during the placement of esthetic restorations is superior, compared to the traditional restorative techniques. Moreover, any pores or gaps on the surface of the composite placed by means of the layering technique can be easily resolved. Hence, the modeling resin facilitates the reduction of defects in the body of the restoration and aids in improving the mechanical properties. Although these methods are widely used, a potential shortcoming is that these techniques may adversely affect the physical and surface properties of the resin composite. However, it is unknown whether different compositions of adhesives or modeling agents may affect the surface microhardness, surface roughness, and color stability of composites over time.

Official Title
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Evaluation of Resin Composite Posterior Restorations Using Modeling Resin Insertion Technique Versus Conventional Composite Placement Technique in Class I Lesions: Randomized Clinical Trial

Conditions
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Class I Composite Restorations

Intervention / Treatment
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* Procedure: Modeling Resin Insertion Technique
* Procedure: Conventional resin composite Incremental Placement Technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants: Adult Patients (25-45). Good oral hygiene (plaque index score 0 or 1). Absence of damaging habits (e.g. bruxism, nail biting, tooth clenching and mouth breathing). Teeth: Vital teeth with a normal appearance and morphology. Primary carious lesions in molar teeth. Exclusion Criteria: Participants: Patients with bad oral hygiene. Patients with known allergic or adverse reaction to the tested materials. Any uncontrolled systemic disease, pregnant or lactating women and any patient incapable to be present at recall follow up visits. Teeth: Non-vital, fractured, or cracked teeth. Teeth with secondary caries or in need of replacement of existing restorations. Defective restorations adjacent to or opposite the tooth restored in the study. Rampant caries, atypical extrinsic staining of teeth.

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 45 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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Modeling Resin Insertion Technique<br>Resin Composite (Tetric® N-Ceram Nano-hybrid incremental composite) / Wetting Agent (Modeling Resin, Bisco) | Procedure: Modeling Resin Insertion Technique<br>* One drop of modeling resin will be dispensed into a clean mixing well. Following the placement of the resin composite into the prepared site, a composite instrument (round-ended plugger with a diameter of 2 mm) will be dipped into the modeling resin. With modeling resin on the instrument, the resin composite is sculpted and manipulated to the desired shape. This will be repeated with each increment. Each increment will be polymerized for 20 sec with a LED light-curing unit.<br>|
| Placebo Comparator: Conventional Resin Composite Incremental Placement Technique<br>Conventional resin composite incremental placement technique (Tetric® N-Ceram Nano-hybrid incremental composite) | Procedure: Conventional resin composite Incremental Placement Technique<br>* A three-step etch-and-rinse adhesive system will be used according to the manufacturer's instructions. 37.5% phosphoric acid (Kerr Co, Orange, CA, USA) will be applied to the enamel and dentin for a period of 30 s and 15 s, respectively. Subsequently the cavities will then be rinsed with an air/water spray for 15 s. A layer of primer will be applied to the dentin for 30 sec, afterward gentle air-drying for 5 sec. Then, the bond (AdheSE adhesive) will be applied on the enamel and dentin and light cured with a LED curing unit for about 30 sec. Tetric N-Ceram will then be applied using an incremental filling technique, each increment will not exceed 2mm in thickness. Each increment will be polymerized for 20 sec with a LED light-curing unit.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Marginal Discoloration at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to delta (Immediate replacement necessary). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline in Marginal Integrity at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to delta (Immediate replacement necessary). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Color Match at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to charlie (outside the acceptable range). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Surface Roughness at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to delta (Immediate replacement necessary). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Anatomic form (wear) at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to delta (Immediate replacement necessary). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Retention of Restoration at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to charlie (complete loss of restoration). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Secondary Caries at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to bravo (Caries contiguous with the restoration margin). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months | 
| Change from baseline in Postoperative Sensitivity at 3,6,12 & 18 months | Modified US Public Health Service criteria. Possible scores range from alpha (Excellent) to delta (Immediate replacement necessary). | T1: 3 months • T2: 6 months • T3: 12 months • T4: 18 months |