Impact of Laser-modified Abutment Topography on Peri-implant Mucosal Integration

Study Overview
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Brief Summary
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This study is a prospective randomized split mouth study intended to evaluate the healing and health of peri-implant mucosal tissue following placement of titanium abutments with or without laser-etching. Each subject will receive two implants. Following placement of the two 4.2mm diameter implants, one implant will receive (by randomization) a laser-etched abutment ('Laser-Lok'). The other implant will receive a standard, non-etched healing abutment. Subjects will be sequentially subdivided into four groups (n=5) and scheduled for a biopsy of the peri-implant tissues of both implants at either 8 weeks, 4 weeks, 2 weeks or 1 week after implant surgery. These biopsies, about the size of a grain of rice, will be analyzed using immunohistochemical and RNASeq techniques to identify molecular changes in response to laser etching. At approximately 8 weeks after implant surgery, subjects will have abutments removed from both implants and digital impressions taken for final crown fabrication. At approximately 11-12 weeks after implant surgery, final crowns will be placed. Subjects return to clinic at approximately 1 year post surgery for a final study visit to assess the peri-implant mucosa surrounding both implants as measured by bleeding upon probing, probing depth and peri-apical radiography.

Detailed Description
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A dental implant is an artificial root for a missing tooth made out of surgical grade metals, usually titanium, which is placed in the jaw. An implant is designed to provide a strong foundation for an artificial replacement tooth, also called a crown. An abutment is a medical grade connector, usually made of titanium, which is placed on top of the implant, and is designed to hold and connect the crown to the implant. A crown, also called a dental cap is an artificial tooth, generally made of porcelain or surgical grade metals. Osseointegration is defined as the fusion of a dental implant and abutment with the surrounding jaw bone and is a critical step during implant therapy. During this process, the titanium and bone need to become one solid structure (without any intervening inflammatory mucosal tissue in between) for optimum strength and viability. It is hypothesized that use of an abutment whose surface has been etched with a laser (laser-etched) will enhance the attachment of the abutment to the surrounding bone and mucosal tissue and optimize healing. The goal of this research is to compare, by split mouth design, the healing process of peri-implant mucosal tissue adjacent to a standard healing abutment (not laser-etched) versus mucosal tissue healing adjacent to a laser-etched abutment . Each subject will receive two implants. One implant will receive (by randomization) a standard titanium healing abutment that is not laser-etched. The other implant will receive a laser-etched (Laser-Lok) abutment. Subjects will be sequentially subdivided into 4 groups (n=5) and scheduled for a biopsy of peri-implant tissue at both implant sites at either 8 weeks, 4 weeks, 2 weeks or 1 week after implant surgery. The biopsies, about the size of a grain of rice, will be analyzed using histological and molecular techniques to identify cellular changes in response to laser-etching. Approximately 8 weeks after implant placement, subject will have abutments removed and digital impressions taken for final crown fabrication. At approximately 11-12 weeks post implant placement, final crowns will be placed. Subjects return to clinic at approximately 1 year post surgery for a final study visit to assess the peri-implant mucosa around both implants as measured by bleeding upon probing, probing depth and peri-apical radiography.

Official Title
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The Laser-Lok Trial: Impact of Laser-modified Abutment Topography on Peri-implant Mucosal Integration

Conditions
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Dental Implant Failure Nos

Intervention / Treatment
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* Device: Laser-Lok abutment
* Device: Standard healing abutment


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult, able to provide informed written consent and available for 1 year follow-up visit Have 2 edentulous sites requiring single tooth implants for restoration in two separate quadrants Implant sites must be restorable with 4.2mm diameter implants Have natural teeth adjacent (at least unilaterally) to proposed implant sites Able to pay for implant crowns at UIC College of Dentistry postgraduate fees to complete treatment Exclusion Criteria: Uncontrolled/rampant caries or periodontal disease Unable to demonstrate adequate home oral hygiene smoker within the past 6 months ASA Class 3+, immune-compromised Pregnant or planning to become pregnant within 6 months Severe bruxism History of bisphosphonate use Bone grafting required for implant placement Missing tooth is too small to be restored using a 4.2mm implant

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: Prospective randomized split mouth designed study intended to evaluate the healing and health of peri-implant mucosa following placement of titanium abutments with or without laser-etching. Each subject will receive two dental implants. One implant will receive (by randomization) a laser-etched (Laser-Lok) abutment. The other implant will receive a standard healing abutment (not laser-etched).
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Laser-Lok abutment<br>Laser-etched abutment | Device: Laser-Lok abutment<br>* Each subject will receive two dental implants. One implant will receive (by randomization) a laser-etched (Laser-Lok) abutment.<br>* Other names: laser-etched abutment;|
| Active Comparator: Standard Healing abutment<br>Standard abutment which is not laser-etched | Device: Standard healing abutment<br>* Each subject will receive two dental implants. One implant will receive (by randomization) receive a standard healing abutment (not laser-etched).<br>* Other names: non-laser etched abutment;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Molecular profiling of peri-implant mucosal tissues | Fold change (> 2 fold) expression of junctional epithelial gene expression (e.g. ODAM., FDSCP) | 1 week, 2 week, 4 week, and 8 week after implant surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Radiographic parameter | mm change (> 0.1 mm) in peri-implant bone levels at mesial and distal positions | 1 week and 1 year post implant surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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RNASeq, mucosal integration