Implant Placement Depth and Peri-Implant Tissue Outcomes

NCT07535528 | Not Yet Recruiting

• 1 other identifier: UV-INV-ETICA-3792383
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

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.

Conditions

Dental Implant Placement; Soft Tissue Management in Subcrestal Dental Implants; Marginal Bone Loss

Keywords

Dental implant; Subcrestal placement; Marginal bone loss; Insertion depth

Outcome Measures

Primary Outcomes (1)

• 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)

  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.

Secondary Outcomes (3)

• 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.

• 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.

• Implant success

  From the time of surgery through the end of the 12-month follow-up period after definitive prosthesis placement.

Other Outcomes (1)

• Baseline characteristics

  At enrollment time.

Study Arms (4)

-2 mm subcrestal implant placement with 2-mm slim transmucosal abutments

EXPERIMENTAL

Participants in this group will receive implants placed 2 mm below the level of the alveolar bone crest. Implants will share the same design, surface characteristics, and prosthetic connection, including platform switching. Slim transmucosal abutments with a height of 2-mm will be placed according to the subcrestal depth to ensure an adequate transmucosal profile and a stable relationship between the implant, peri-implant soft tissues, and the prosthetic restoration

Procedure: Subcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol

-2 mm subcrestal implant placement with 3-mm slim transmucosal abutments

EXPERIMENTAL

Participants in this group will receive implants placed 2 mm below the level of the alveolar bone crest. Implants will share the same design, surface characteristics, and prosthetic connection, including platform switching. Slim transmucosal abutments with a height of 3-mm will be placed according to the subcrestal depth to ensure an adequate transmucosal profile and a stable relationship between the implant, peri-implant soft tissues, and the prosthetic restoration.

Procedure: Subcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol

-4 mm subcrestal implant placement with 4-mm slim transmucosal abutments

EXPERIMENTAL

Participants in this group will receive implants placed 4 mm below the level of the alveolar bone crest. Implants will share the same design, surface characteristics, and prosthetic connection, including platform switching. Slim transmucosal abutments with a height of 4-mm will be placed according to the subcrestal depth to ensure an adequate transmucosal profile and a stable relationship between the implant, peri-implant soft tissues, and the prosthetic restoration.

Procedure: Subcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol

-4 mm subcrestal implant placement with 5-mm slim transmucosal abutments

EXPERIMENTAL

Participants in this group will receive implants placed 4 mm below the level of the alveolar bone crest. Implants will share the same design, surface characteristics, and prosthetic connection, including platform switching. Slim transmucosal abutments with a height of 5-mm will be placed according to the subcrestal depth to ensure an adequate transmucosal profile and a stable relationship between the implant, peri-implant soft tissues, and the prosthetic restoration.

Procedure: Subcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol

Interventions

Subcrestal Implant Placement with Transmucosal Abutment and One Abutment-One Time Protocol PROCEDURE

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.

-2 mm subcrestal implant placement with 2-mm slim transmucosal abutments; -2 mm subcrestal implant placement with 3-mm slim transmucosal abutments; -4 mm subcrestal implant placement with 4-mm slim transmucosal abutments; -4 mm subcrestal implant placement with 5-mm slim transmucosal abutments

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of Valencia: lead

Study Sites (1)

University of Valencia

Valencia, Valencia, 46003, Spain

Location

Study Officials

• Ana Verónica Blanco Besteiro, DDS, MSc and PhD candidate

  University of Valencia

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Juan Carlos Bernabeu Mira, DDS, MSc, PhD

CONTACT

+34 697348312; juan.c.bernabeu@uv.es

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, PhD

Study Record Dates

• First Submitted: April 7, 2026
• First Posted: April 17, 2026
• Study Start (Estimated): May 15, 2026
• Primary Completion (Estimated): November 20, 2026
• Study Completion (Estimated): July 20, 2027
• Last Updated: April 17, 2026

Record last verified: 2026-04

Locations

ES (1)