The goal of this randomized clinical trial is to investigate the influence of supracrestal soft tissue on abutments of different heights (2-mm vs. 3-mm) and shapes (cylindrical abutment vs. concave abutment) on changes in the marginal bone level (bone loss and bone remodeling) in healthy, partially edentulous volunteer patients undergoing implant-supported rehabilitation.
The main questions it aims to answer are:
* Is there any difference in marginal bone loss for different abutment shapes and heights? * Do the shape and height of the abutment affect implant success?
All participants will receive bone-level dental implants placed approximately 2-mm below the bone crest, each receiving a different type of abutment and researchers will see whether the shape and height of the abutment influence the success of the implant, periodontal probing depth (PPD), and bleeding on probing (BoP) comparing four groups of patients:
1. 2-mm high abutments with cylindrical shape. 2. 2-mm high abutments with concave shape. 3. 3-mm high abutments with cylindrical shape. 4. 3-mm high abutments with concave shape.
Clinical and radiographic assessments will be performed at abutment placement, at definitive prosthesis placement, and at 1, 3, 6, and 12 months after loading to measure marginal bone loss and peri-implant parameters.
Adults aged 18 years or older.
Posterior edentulism (premolars/molars).
Good general and oral health, with controlled plaque and bleeding indices.
Sufficient bone height and width for implant placement without the need for bone regeneration procedures. Patients who require indirect sinus lift procedure simultaneously with implant placement may be included in the study.
Presence of medical conditions that contraindicate implant surgery, such as heavy smoking (>10 cigarettes per day), severe bruxism, pregnancy or breastfeeding, bisphosphonate therapy, and patients undergoing chemotherapy or radiotherapy in the head and/or neck area.
Active periodontal disease or peri-implant infection.
Uncooperative patients or patients unable to complete follow- up.
Implant failures.
Parallel
Bone-Level Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol
Procedure/SurgeryParticipants will receive bone-level dental implants placed approximately 2 mm below the bone crest in a healed posterior site of the maxilla or mandible. The implants will be placed using biological drilling protocol and inserted with a final torque of at least 35 Ncm following the manufacturer's instructions . A transmucosal abutment according to the applicable randomization will be connected at the time of surgery with a final torque of at least 30 Ncm, following the "one abutment-one time" philosophy in order to avoid any changes in hard and soft peri-implant tissues.
Changes in peri-implant marginal bone level (mm)
Parallelized periapical radiographs will be obtained and a calibrated digital tool will be used to determine the vertical distance from the implant-abutment junction to the most coronal bone-to-implant contact on the mesial and distal sides. Unit of measure: Milimeters (mm)
Peri-implant probing depth (mm)
Peri-implant soft tissue condition will be assessed by recording PPD using a periodontal probe at six surfaces per implant (mesiobuccal, midbuccal, distobuccal, and the corresponding lingual/palatal sites) to calculate the mean of every implant. Unit of measure: Milimeters (mm)
Bleeding on probing (presence/absence)
Bleeding on probing will be measured by gently passing a periodontal probe (using \~20-25g of force) to the base of the sulcus/pocket of the prosthesis at six surfaces per implant (mesiobuccal, midbuccal, distobuccal, and the corresponding lingual/palatal sites), then waiting 30 seconds to observe bleeding. It will be recorded as a dichotomous score (yes/no). Unit of measure: Percentage of sites showing bleeding per implant.
Implant success
Assessment of the implants will follow the criteria outlined by Misch et al. (2008) categorizing them into success (optimal health), satisfactory survival, compromised survival, or failure.
General variables
Patient age and sex, smoking habit (no smoking or ≤10 cigarettes/day), brushing habit (0, 1-2 or 3 times/day), edentulism (interdental or free end), phenotype (thin or thick), antagonist (natural teeth, bridge on teeth, implant rehabilitation or removable rehabilitation), cause of dental loss (caries, periodontitis or fracture), arch, quadrant, and soft tissue thickness (in mm) will be collected.
Click on the lead sponsor to view all of their trials.
