Dental Implant Placement, Marginal Bone Loss, Soft Tissue Management in Subcrestal Dental Implants
Conditions
Keywords
Dental implant, Subcrestal placement, Marginal bone loss, Insertion depth
Brief summary
The primary aim of this randomized clinical trial is to evaluate the influence of subcrestal implant placement depth (-2 mm vs -4 mm) on peri-implant marginal bone level changes, including marginal bone loss and bone remodeling. Secondary outcomes include implant success, peri-implant probing depth (PPD), and bleeding on probing (BoP). Partially edentulous patients requiring fixed implant-supported prosthetic rehabilitation with two implants in posterior maxillary or mandibular regions will be included. Implants will be placed subcrestally at either -2 mm or -4 mm from the bone crest, following a submerged healing protocol. Allocation to insertion depth will be randomized. Marginal bone level changes will be assessed using standardized periapical radiographs at second-stage surgery, prosthesis placement, and at 1, 3, 6, and 12 months after functional loading. PPD and BoP will be recorded at the same time points.
Interventions
PROCEDURESubcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol
Participants will receive bone-level dental implants placed subcrestally at either -2 mm or -4 mm below the bone crest in healed posterior sites of the maxilla or mandible, according to randomization. Implant placement will follow the manufacturer's drilling protocol, achieving a final insertion torque of at least 35 Ncm. A transmucosal abutment will be connected at the time of surgery, with height selected based on implant placement depth (2-3 mm for -2 mm placement and 4-5 mm for -4 mm placement). The abutment will be tightened to a final torque of at least 30 Ncm following a one abutment-one time protocol.
Sponsors
University of Valencia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Patients ≥18 years old with partial edentulism. * Need for rehabilitation with fixed implant-supported prostheses in posterior regions. * Availability of minimum bone height for implants ≥6 mm in length. * Minimum bone width without the need for guided bone regeneration. * Supracrestal soft tissue thickness ≥2 mm. * Non-smokers or smokers of ≤10 cigarettes/day. * Plaque index and bleeding on probing \<20%. * Probing depth ≤3 mm. * Signed informed consent.
Exclusion criteria
* Systemic diseases contraindicating implant surgery. * Treatment with intravenous bisphosphonates. * Head and neck radiotherapy. * Uncontrolled diabetes. * Pregnancy or breastfeeding. * Alcohol or drug use. * Psychiatric disorders. * Need for bone regeneration procedures. * Inability to complete follow-up. * Implant failure during the study period.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in peri-implant marginal bone level (mm) | From abutment placement (baseline time [TB]), 1 month post (T1), and at 3 (T3) (prosthetic loading) , 6 (T6), and 12 (T12) months after definitive prosthesis placement. | 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) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Peri-implant probing depth (mm) | 1 month post-op (T1), and at months 3 (T3) (prosthetic loading) , 6 (T6), and 12 (T12) after definitive prosthesis placement. | 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) | 1 month post-op (T1), and at months 3 (T3) (prosthetic loading) , 6 (T6), and 12 (T12) after definitive prosthesis placement. | 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 | From the time of surgery through the end of the 12-month follow-up period after definitive prosthesis placement. | Assessment of the implants will be performed by categorizing them into: success (optimal health), satisfactory survival, compromised survival, or failure. |
Countries
Spain
Contacts
PRINCIPAL_INVESTIGATORAna Verónica Blanco Besteiro, DDS, MSc and PhD candidate
University of Valencia
Outcome results
None listed