Subcrestal vs Juxtacrestal PRAMA Implants With Variable Necks

NCT07107464 | Active Not Recruiting

• 1 other identifier: 2024/02
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to understand how different implant neck designs and placement depths affect the surrounding bone and peri-implant tissue (the tissue around a dental implant) in adults who need implants in the back areas of the mouth (molars and premolars). The main questions it aims to answer are: Does placing implants deeper under the bone crest (subcrestally) help preserve more bone and peri-implant tissue over time? Do implants with longer, conical necks and micro-threaded surfaces result in more stable peri-implant tissue than implants with shorter necks? Researchers will compare three types of one-piece dental implants with different neck heights (short, standard, and long), placed at different depths in the jawbone, to determine which combination better maintains bone and peri-implant tissue levels. Participants will: Receive two dental implants in the posterior upper or lower jaw Be randomly assigned to one of three groups depending on implant neck design and placement depth Undergo implant surgery using a digital workflow, with healing over three months Be rehabilitated with custom zirconia bridges Return for regular clinical and imaging checkups over a period of at least 3 years This study aims to generate evidence that helps clinicians choose implant designs and techniques that promote long-term peri-implant tissue health.

Conditions

Edentulism; Dental Implantation, Endosseous; Marginal Bone Loss; Periimplant Bone Loss

Keywords

edentulism; dental implants; Peri-Implant Bone Loss; Subcrestal Implant Placement; One-Piece Implants; Implant Neck Design; Convergent Implant Neck

Outcome Measures

Primary Outcomes (1)

• Change in Peri-Implant Bone Height Over Time

  Vertical changes in marginal bone level from the implant-abutment junction to the first bone-to-implant contact (BIC) at mesial and distal aspects, measured on standardized periapical radiographs, CBCT, and digital scans. Unit of Measure: Millimeters (mm)

  Baseline (prosthesis delivery), 6 months, and annually up to 3 years post-loading

Secondary Outcomes (5)

• Volumetric Change in Peri-Implant Tissues

  Baseline (prosthesis delivery), 6 months, and annually up to 3 years post-loading

• Tissue Volume Difference by Crown Emergence Profile

  6 months and annually up to 3 years post-loading

• Probing Pocket Depth at Implant Sites

  6 months and annually up to 3 years post-loading

• Plaque Index at Implant Sites (0-3 scale)

  6 months and annually up to 3 years

• Bleeding on Probing at Implant Sites (percentage of sites)

  6 months and annually up to 3 years

Study Arms (3)

Short Neck Implant - Crestal Placement

EXPERIMENTAL

Participants in this arm receive one-piece dental implants with a short transmucosal neck (1.8 mm total height, hyperbolic convergent shape) placed at the level of the bone crest (crestal placement). The implant features a ZirTi surface and Ultrathin Threaded Microsurface across the entire neck.

Device: Short Neck Implant - Crestal Placement

Standard Neck Implant (1 mm Subcrestal Placement)

EXPERIMENTAL

Participants in this arm receive one-piece dental implants with a standard transmucosal neck (0.8 mm cylindrical plus 2.0 mm convergent portion) placed 1 mm below the bone crest. The implant surface includes micro-threads throughout the neck to promote tissue stability.

Device: Standard Neck Implant - 1 mm Subcrestal Placement

Long Neck Implant (2 mm Subcrestal Placement)

EXPERIMENTAL

Participants in this arm receive one-piece dental implants with a long transmucosal neck (0.8 mm cylindrical plus 3.0 mm convergent portion) placed 2 mm below the bone crest. This arm tests the effect of deeper placement combined with extended neck geometry.

Device: Long Neck Implant - 2 mm Subcrestal Placement

Interventions

Short Neck Implant - Crestal Placement DEVICE

A one-piece endosseous dental implant with a 1.8 mm short convergent neck, placed at the bone crest. Implant used: PRAMA implant (Sweden \& Martina, Italy) with UTM surface treatment.

Short Neck Implant - Crestal Placement

Standard Neck Implant - 1 mm Subcrestal Placement DEVICE

A one-piece endosseous dental implant with a standard-length neck (2.8 mm total; 0.8 mm cylindrical + 2 mm convergent), placed 1 mm subcrestally. Implant used: PRAMA implant (Sweden \& Martina, Italy) with UTM surface.

Standard Neck Implant (1 mm Subcrestal Placement)

Long Neck Implant - 2 mm Subcrestal Placement DEVICE

A one-piece endosseous dental implant with a long transmucosal neck (3.8 mm total; 0.8 mm cylindrical + 3 mm convergent), placed 2 mm subcrestally. Implant used: PRAMA implant (Sweden \& Martina, Italy) with UTM surface.

Long Neck Implant (2 mm Subcrestal Placement)

Eligibility Criteria

• Age: 21 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 21 years or older.
• Presence of an edentulous area in the posterior maxilla or mandible (premolar or molar region) that allows the placement of two dental implants.
• Alveolar bone height sufficient to permit implant insertion with a minimum depth of 6 mm, and total implant length of at least 10 mm.
• Indication for implant-supported prosthetic restoration (2- or 3-unit fixed dental bridge).
• Good general health with no contraindications for oral surgical procedures.
• Not pregnant at the time of screening.
• Willingness and ability to sign written informed consent and comply with study procedures.

You may not qualify if:

• Presence of uncontrolled systemic disease (e.g., diabetes, cardiovascular disorders, immunosuppression).
• History of chemotherapy or radiotherapy to the head or neck region.
• Heavy smokers (defined as \>10 cigarettes per day)
• Previous bone regeneration or grafting procedures at the target implant site.
• Use of medications known to interfere with bone metabolism (e.g., bisphosphonates, corticosteroids).
• Poor oral hygiene or active periodontal disease that may compromise implant success.
• Known allergy or hypersensitivity to implant materials used in the study-

Sponsors & Collaborators

• ARDEC Academy: lead

Study Sites (1)

University of Medical Sciences of Havana

Havana, 10400, Cuba

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Allocation concealment is ensured via sealed opaque envelopes opened at the time of surgery. The surgeon is blinded to group assignment until after flap elevation, and the prosthetic team is unaware of crown design assignment until delivery. The outcomes assessor responsible for radiographic, CBCT, and 3D volumetric evaluations remains blinded to treatment allocation throughout the study.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: NETWORK
• Responsible Party: SPONSOR

Model Details: Split-mouth randomized controlled trial

Study Record Dates

• First Submitted: July 19, 2025
• First Posted: August 6, 2025
• Study Start: June 3, 2024
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: August 6, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will not share

Locations

CU (1)