Cementation Techniques for Single-tooth Implant Crowns

Study Overview
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Brief Summary
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Cement retention has been widely used for implant-supported fixed partial dentures in daily dental practice. The cementation approach indeed offers straightforward clinical application protocol which is basically conceptualized for tooth/teeth supported fixed restorations. However, removal of excess cement around implant restorations presents specific difficulties. More importantly, there are certain biological consequences due to residual cement leftover in peri-implant sulcus. There is no evidence based guidance with regards to cementation techniques applied for implant supported fixed restorations due to limited clinical studies. Therefore the aim of this clinical trial is to compare three different cementation technique with regards to removal of excess cement and other clinical subsidiaries (abutment margin, crown surface and contour) involving indirectly as well.

Detailed Description
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Single-tooth implant crowns to replace missing molar tooth were addressed to qualify and quantify residual cement on implant-abutment complex and peri-implant soft tissue following cementation. Thirty bone-level dental implants of one kind enrolled in the study. Prior to delivery of screw-retained crowns completed for usual treatment, implants were allocated randomly to a trial comparison group. Three different cement loading approach, ten in each group, was applied using cement-retained trial crowns on prefabricated metal abutments. Following completion of the assigned cementation technique, the trial crown was removed with its abutment accessing from the occlusal hole prepared after removal of excess cement. Then, the presence of residual cement on implant-abutment complex and implant soft tissue in accordance with axial and proximal surfaces was qualified. To quantify the amount of residual cement in accordance with location and distribution, the crown-abutment complex was digitized three-dimensionally using an intra-oral scanner. The output of surface data was evaluated in virtual 3-D image for cement excess, when detected location in the abutment-crown complex is recorded, area and distribution was calculated using a software. The frequency of occurrence and quantity of residual cement of 3-different cementation techniques was statistically evaluated using logistic and linear regression model separately considering abutment margin, crown surface and contour.

Official Title
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Effect of Cementation Technique Applied for Single-tooth Implant Crowns on Residual Cement: A Three-arm Parallel-group Randomized Clinical Trial

Conditions
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Cementation (MeSH Unique ID: D002484), Dental Implant-Abutment Design (MeSH Unique ID: D059605), Crown (MeSH Unique ID: D003442) Surfaces, Contour: Crown (MeSH Unique ID: D003442) - Dental Implant (MeSH Unique ID: D015921) Abutment

Intervention / Treatment
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* Other: zinc polycarboxylate (with the requirements of ISO 9917)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: completed growth and development periodontally and dentally healthy conditions missing single molar tooth without free-end edentulism bone-level standard diameter of a specific implant from one manufacturer complication free healing period for osseointegration following straightforward surgical implant placement natural dentition or fixed restoration in dental arch signing of informed consent form Exclusion Criteria: absolute systemic contraindications for implant surgery (e.g. bone cancer, radiation therapy) relative systemic contraindications for implant surgery (e.g. diabetes, steroid therapy) risk factors (e.g. smoking, limited mouth opening)

Ages Eligible for Study
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Minimum Age: 18 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Technique I<br>Loading of a zinc polycarboxylate (with the requirements of ISO 9917) cement to fulfill the crown Cement: Poly-F, DentsplySirona, York, Pennsylvania, United States Mixing Ratio: 1 scoop powder: 2 drops liquid Mixing Time (extraoral): 30 seconds Working Time (extraoral): 45 seconds Application (extraoral): placement of mixture into crown using a heidemann Spatula Setting Time (intraoral): 2-8 minutes | Other: zinc polycarboxylate (with the requirements of ISO 9917)<br>* intraoral cementation of single-tooth implant crowns with three different technique, intraoral removal of cement excess upon setting<br>|
| Active Comparator: Technique II<br>Loading of a zinc polycarboxylate (with the requirements of ISO 9917) to fill the coronal half of the crown Cement: Poly-F, DentsplySirona, York, Pennsylvania, United States Mixing Ratio: 1 scoop powder: 2 drops liquid Mixing Time (extraoral): 30 seconds Working Time (extraoral): 45 seconds Application (extraoral): placement of mixture into crown using a heidemann Spatula Setting Time (intraoral): 2-8 minutes | Other: zinc polycarboxylate (with the requirements of ISO 9917)<br>* intraoral cementation of single-tooth implant crowns with three different technique, intraoral removal of cement excess upon setting<br>|
| Active Comparator: Technique III<br>Application of a zinc polycarboxylate (with the requirements of ISO 9917) to the axial walls of internal surface of crown Cement: Poly-F, DentsplySirona, York, Pennsylvania, United States Mixing Ratio: 1 scoop powder: 2 drops liquid Mixing Time (extraoral): 30 seconds Working Time (extraoral): 45 seconds Application (extraoral): application of mixture into crown using a bonding applicator tip Setting Time (intraoral): 2-8 minutes | Other: zinc polycarboxylate (with the requirements of ISO 9917)<br>* intraoral cementation of single-tooth implant crowns with three different technique, intraoral removal of cement excess upon setting<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| visual assessment of residual cement on crown-abutment complex | removal of cemented crown-abutment complex to detect excess cement on the mesial, distal, buccal and lingual surfaces of crown and abutment separately scoring: presence or absence | 15 minutes | 
| measurement of residual cement area and distribution | digitalization of the removed crown-abutment complexes those scored with cement presence, then using a software, virtual selection of existing cement to calculate the area in millimeter square and to define the direction and the extension in millimeters on the mesial, distal, buccal and lingual surfaces of crown and abutment separately | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| visual assessment of residual cement around the peri-implant soft tissue | removal of cemented crown-abutment complex to detect excess cement on the peri-implant soft tissue contacting the mesial, distal, buccal and lingual surfaces of crown-implant complex scoring: presence or absence | 15 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cementation, dental implant, crown, periimplantitis