Patient Perception and Clinical Efficacy of a Collagen Matrix for the Treatment of Peri-implantitis

Study Overview
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Brief Summary
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This is a multi-centre, randomized clinical trial which evaluates the efficiency of the collagen xenograft (Muco-Graft®) in comparison to the autologous connective tissue graft for the augmentation of keratinized mucosa and gaining hygienic access to the implants diagnosed with peri-implantitis.

Detailed Description
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Nowadays, there is not enough evidence that evaluates the patient's perception of utilizing the soft tissue substitutes in comparison to the autologous connective tissue graft for the augmentation of the keratinized mucosa and gain of hygienic access to the implants with infectious pathology and with minimum or absent keratinized mucosa. Therefore, the aim of the study is to evaluate the change of clinical parameters of peri-implant health and the patient perception of the procedure for augmentation of the keratinized tissues around dental implants with peri-implantitis. The hypothesis is that collagen matrix of porcine origin is associated with lower patient morbidity, in comparison with autologous connective-tissue graft, when used for the augmentation of the keratinized tissues around endosseous dental implants with infectious pathology and with minimum or absent KT mucosa. A sample 48 patients will be recruited basing upon the diagnosis of peri-implantitis and absent or insufficient peri- implant mucosa. 1 month after the non-surgical treatment, surgical procedure will be performed. Peri-implant clinical and radiographic parameters, as well as patient perception of the therapy provided, will be evaluated before and at various stages (up to 52 weeks) after the surgical intervention. Also, change of vestibulum depth will be analyzed, as well as the time spent for the procedure measured.

Official Title
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Patient Perception and Clinical Efficacy of Geistlich Mucograft® vs. Autologous Connective Tissue Graft for the Treatment of Peri-implantitis: Multi-centre Randomized Clinical Trial

Conditions
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Peri-Implantitis

Intervention / Treatment
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* Other: Acellular collagen matrix
* Other: Autogenous free gingival graft


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent after the detailed information on the study. Adults aged at least 18 years old. Candidates for receiving augmentation of the peri-implant keratinized mucosa. Presence of the implant diagnosed with peri-implantitis (radiographic bone loss > 2 mm, with a probing depth > 5 mm, bleeding and/or suppuration (Lang et al., 2011)). Absent or insufficient keratinized peri-implant mucosa (<2 mm). Exclusion Criteria: General contraindications for the dental/surgical treatment; Inflammatory or autoimmune disease of the oral cavity; Implant with radiographic intraosseous defects more than 3 mm; Smokers > 10 cig/day; Allergy to collagen or analgesics/anti-inflammatory non-steroid drugs; History of cancer in various parts of the body which required radiotherapy or chemotherapy during the last 5 years; Radiotherapy of the head or neck in the last 5 years; Actual medication with immunosuppressors, bisphosphonates or high doses of corticosteroids; Pregnant or lactating women; Women in fertile age, who do not use effective methods of contraception; Participants of other studies of biomedical investigation during the last 24 weeks before initiation of the study.

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Multi-centre randomized clinical trial (2 centres) with the duration of 102 weeks for the evaluation of efficiency on the new collagen xenograft (Muco-Graft®) in comparison to the autologous connective tissue graft for the augmentation of keratinized mucosa and gaining hygienic access to the implants diagnosed with peri-implantitis
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Acellular collagen matrix<br>In a test group, partial thickness-flap will be elevation will be performed, in order to create the vascular recipient bed for the randomized graft. Implant surface will be treated with ultrasound device, glycine powder and implantoplasty in case of the exposure of the rough surface. Acellular collagen matrix will be adapted and suture to the vascular bed. | Other: Acellular collagen matrix<br>* 3D collagen matrix consists of the collagen porcine type I and III<br>|
| Active Comparator: Autogenous free gingival graft<br>In a control group, partial thickness-flap will be elevation will be performed, in order to create the vascular recipient bed for the randomized graft. Implant surface will be treated with ultrasound device, glycine powder and implantoplasty in case of the exposure of the rough surface. Free gingival graft will be harvested from the zone of the posterior palate, and then adapted and sutured to the vascular bed. | Other: Autogenous free gingival graft<br>* Autogenous graft harvested from the posterior palate<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in width of keratinized peri-implant mucosa | Measured by periodontal probe (UNC-15), as mm of keratinized mucosa in the midbuccal portion of the implant of interest | Baseline, 0, 1, 2, 4, 12, 26 and 52 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Bleeding on probing | Measured as presence or absence (binary value) of bleeding 10 seconds after probing with the periodontal probe in 6 point around each implant | Baseline, 0, 1, 2, 4, 12, 26 and 52 weeks | 
| Probing depth | Measured by periodontal probe (UNC-15) in millimeters in 6 points around each implant, and defined as a distance from the mucosal margin to the bottom of the peri-implant pocket | Baseline, 0, 1, 2, 4, 12, 26 and 52 weeks | 
| Recession | Measured by periodontal probe (UNC-15) in millimeters in 6 points around each implant, and defined as a distance from the implant platform to the mucosal margin | Baseline, 0, 1, 2, 4, 12, 26 and 52 weeks | 
| General satisfaction by the treatment | Measured by a questionnaire, using the visual analogue scale, in values from 0 to 100 | 0, 1, 2, 4, 12, 26 and 52 weeks | 
| Duration of surgery | Measured by the electronic timer in minutes, starting from the moment of first incision and ending with a last suture | after completion of surgical intervention | 
| Vestibulum depth | Measured in mm by a periodontal probe, as a distance from the mucosal margin to the point of greatest concavity of the mucobuccal fold | Baseline, 0, 1, 2, 4, 12, 26 and 52 weeks |