Health of Peri-implant Tissues Adjacent to Zirconia

Study Overview
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Brief Summary
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Background: The control and maintenance of implants, bone tissue and soft tissue are fundamental for the clinical success of implant prostheses (PSIs). The type of ceramic surface finish can modify the biological response of peri-implant tissues adjacent to PSIs over time. Objective: To prospectively assess whether the peri-implant health of soft and hard tissues adjacent to monolithic zirconia PSIs varies with the type of surface finish (glazed or polished). It will also be evaluated if the patient perceives any clinical, comfort or satisfaction difference. Methodology: The study design is a randomized, prospective, paired clinical trial, with intra-subject comparison. The sample will consist of consecutive patients in need and indication for treatment with monolithic zirconia PSIs, attended at the Military Policlinic of Porto Alegre and in a private practice by a single specialist researcher. For each PSI, the allocation of a glazed or polished surface in contact with the soft gingival tissue will be randomized on the mesial and distal sides of the crown. Data will be collected by routine clinical and radiographic examination with a focus on peri-implant health (hygiene index, gingival bleeding index, crestal bone level), satisfaction questionnaire and intraoral images (thermography and photographs), after one week of installation of the PSI and in six months, one year and two years. The data will be analyzed by descriptive and inferential statistics, at the significance level of 0.05.

Detailed Description
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The control and maintenance of implant, bone and soft tissue are fundamental for the clinical success of prostheses over implants (PSIs). The type of ceramic surface finish can modify the biological response of peri-implant tissues adjacent to PSIs over time. AIM To prospectively assess whether the peri-implant health of soft and hard tissue adjacent to monolithic PSIs varies with the type of surface finish (glazed or polished). METHODS The study design is a randomized, prospective, paired, clinical trial with intra-subject comparison, and the research protocol will follow the Resolution 466/12 of the Brazilian National Health Council and the Declaration of Helsinki. Sample A non-probabilistic sample will consist of consecutive patients in need of treatment with unitary PSIs made of monolithic zirconia, being attended at the Military Polyclinic of Porto Alegre and in a private practice by the same specialist researcher (DBS). Patients will be selected according to the eligibility criteria. Sample size calculation: In the systematic review of Linkevicius and Vaitelis (2015) on the effect of zirconia or titanium abutments on peri-implant tissues, the 11 clinical studies included for biological outcomes had samples from 11 to 81 patients, with 11 to 45 abutments. In a total of 145 zirconia abutments, 12 (8.2%) had biological complications. There is no current clinical studies on glaze and PSI polishing in monolithic zirconia and outcomes of peri-implant health. So, a priori, the initial sample will consist of 30 PSIs (30 pairs to be compared: Glaze vs. Polishing). The definitive sample size will be calculated after preliminary data analysis from the initial six months of data collection. PSIs crowns will be made on metallic abutments (Variobase or Anatomic Abutment, Straumann) and milled in monolithic zirconia (Amann Girrbach, Austria), using a CAD/CAM technique with molding or intra-oral scanning and in-lab milling. For each PSI, the mesial and distal faces will receive one experimental treatment (surface finishing) at random, to be defined by drawing lots: glazed surface treatment (Ceramill Stain & Glaze Kit), or polished surface treatment (polishing rubbers kit in the sequence indicated by the manufacturer - EVE DIACERA Finishing and Polishing Kit, EVE Ernst Vetter GmbH - Germany). All PSIs will be installed according to standardized clinical protocol in the routine of dental clinics where the patients will be seen. After installing the PSI, the clinical data will be collected by clinical-radiographic exam and photographs at the following times: after one week of installation of the PSI (T0 - baseline) and in six months (T1), one year (T2) and two years (T3) of follow-up. Clinical-radiographic Examination A single trained examiner (D.B.S.) will carry out the collection of clinical and radiographic data for each PSI installed through non-invasive procedures already used in dentistry. In the clinical exam the following aspects will be evaluated on each face (glazed or polished) of the PSI: Hygiene Index: will be visually evaluated the presence of bacterial plaque (biofilm) and the presence of visible inflammation. Index of Gingival Bleeding: Gingival probe around the zirconia crown, as per the last consensus of Periodontics (Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions). Patient Satisfaction: a 100-mm visual analogue scale will be used Infrared thermography Radiographic evaluation for peri-implant levels analysis (potential bone loss) Statistical analysis The data will be analyzed by descriptive and inferential statistics (alpha = 0.05).

Official Title
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Health of Peri-implant Tissues Adjacent to Glazed or Polished Zirconia Surface: a Randomized, Intra-subject, Clinical Trial

Conditions
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Peri-Implantitis

Intervention / Treatment
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* Device: Glazing
* Device: Polishing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healing time of at least two months for patients who underwent extraction in areas to be rehabilitated with implants Adequate bone volume at the implant site (ie, sufficient for placement of an implant of at least 3.3 mm in diameter and 6 mm in length) assessed by preoperative CT and clinical evaluation. Use of Straumann bone level or conical bone level implants, with NC or RC platforms. Exclusion Criteria: Patients with systemic diseases (e.g., heart disease, leukocyte and coagulation disorders, metabolic disorders, immunosuppression) History of radiotherapy in the head and neck region Current treatment with steroids and/or bisphosphonates Neurological or psychiatric impairment that can interfere with good oral hygiene Smoking (more than 10 cigarettes a day) History of illicit drug or alcohol abuse

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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: The study design is a randomized, prospective, paired, clinical trial with intra-subject comparison. Each zirconia crown to be placed over the dental implant has two sides (mesial and distal), which will receive a randomised surface finishing treatment in the laboratory fabrication procedure.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Glazed surface<br>One side of the zirconia crown will receive glazed surface treatment according to standard laboratory procedure and manufacturer's recommendations (Ceramill Stain & Glaze Kit). | Device: Glazing<br>* The zirconia surface will be submitted to a vitrification procedure (glazing) in a specific ceramic oven using the Ceramill Stain & Glaze Kit, following the manufacturer's instructions.<br>|
| Experimental: Polished surface<br>The contralateral side of the zirconia crown will receive polished surface treatment (polishing rubbers kit in the sequence indicated by the manufacturer - EVE DIACERA Finishing and Polishing Kit, EVE Ernst Vetter GmbH - Germany). | Device: Polishing<br>* The zirconia surface will be submitted to a polishing procedure using a polishing rubbers kit in the sequence indicated by the manufacturer (EVE DIACERA Finishing and Polishing Kit, EVE Ernst Vetter GmbH - Germany).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from baseline Hygiene Index at six months | Hygiene Index: will be visually evaluated the presence of bacterial plaque (biofilm) and the presence of visible inflammation | from one week of installation of the PSI (T0 - baseline) to six months (T1) of follow-up | 
| Change from six-month Hygiene Index at one year | Hygiene Index: will be visually evaluated the presence of bacterial plaque (biofilm) and the presence of visible inflammation | from six months (T1) to one year (T2) of follow-up | 
| Change from one-year Hygiene Index at two years | Hygiene Index: will be visually evaluated the presence of bacterial plaque (biofilm) and the presence of visible inflammation | from one year (T2) to two years (T3) of follow-up | 
| Change from baseline Index of Gingival Bleeding at six months | Index of Gingival Bleeding: Gingival probe around the zirconia crown, as per the last consensus of Periodontics (Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions) | from one week of installation of the PSI (T0 - baseline) to in six months (T1) of follow-up | 
| Change from six-month Index of Gingival Bleeding at one year | Index of Gingival Bleeding: Gingival probe around the zirconia crown, as per the last consensus of Periodontics (Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions) | from six months (T1) and one year (T2) of follow-up | 
| Change from one-year Index of Gingival Bleeding at two years | Index of Gingival Bleeding: Gingival probe around the zirconia crown, as per the last consensus of Periodontics (Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions) | from one year (T2) to two years (T3) of follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in baseline Overal Satisfaction at six months | Patient Satisfaction: a 100-mm visual analogue scale will be used | from one week of installation of the PSI (T0 - baseline) to in six months (T1) of follow-up | 
| Change in six-month Overal satisfaction at one year | Patient Satisfaction: a 100-mm visual analogue scale will be used | from six months (T1) to one year (T2) of follow-up | 
| Change in one-year Overal satisfaction at two years | Patient Satisfaction: a 100-mm visual analogue scale will be used | from one year (T2) to two years (T3) of follow-up | 
| Change in baseline Infrared thermography score at six months | Infrared termograms obtained from a portable infrared camera will be assessed with the dedicated software to obtain a score measure of each region of interest after calibration procedures | from one week of installation of the PSI (T0 - baseline) to six months (T1) of follow-up | 
| Change in six-month Infrared thermography score at one year | Infrared termograms obtained from a portable infrared camera will be assessed with the dedicated software to obtain a score measure of each region of interest after calibration procedures | from six months (T1) to one year (T2) of follow-up | 
| Change in one-year Infrared thermography score at two years | Infrared termograms obtained from a portable infrared camera will be assessed with the dedicated software to obtain a score measure of each region of interest after calibration procedures | from one year (T2) to two years (T3) of follow-up | 
| Change in baseline Bone loss at six months | Radiographic images will be analysed with a specific software for peri-implant level measurements at the vertical implant axis, at the mesial and distal sides | from one week of installation of the PSI (T0 - baseline) to six months (T1) of follow-up | 
| Change in six-month Bone loss at one year | Radiographic images will be analysed with a specific software for peri-implant level measurements at the vertical implant axis, at the mesial and distal sides | from six months (T1) to one year (T2) of follow-up | 
| Change in one-year Bone loss at two years | Radiographic images will be analysed with a specific software for peri-implant level measurements at the vertical implant axis, at the mesial and distal sides | from one year (T2) to two years (T3) of follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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monolithic zirconia, dental implants, peri-implant tissues, surface finishing