Comparison of Two Dental Implant Types and Placement Depths on Bone Around the Implant in Adults Missing Back Teeth

NCT07886762 | Completed

• 1 other identifier: CEImPA 264/19
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial was to compare two ways of placing and restoring dental implants in adults missing one or more back teeth. The main question it aimed to answer was: does a bone-level implant placed 2 mm below the bone crest, with a final abutment that is never removed, preserve more of the bone around the implant than a tissue-level implant placed at the level of the bone crest? Each implant was randomly assigned by coin toss to one of the two treatments. Researchers measured the bone level around the implants on dental X-rays at crown placement, 6 months after loading, and at a final visit 12 to 24 months after loading. They also measured two markers of inflammation (IL-1β and MMP-8) in the fluid around the implants 6 months after loading.

Conditions

Partial Edentulism; Dental Implants; Alveolar Bone Loss

Keywords

bone-level implant; tissue-level implant; subcrestal placement; marginal bone loss; one-abutment one-time; platform switching; peri-implant crevicular fluid; IL-1 beta; MMP-8

Outcome Measures

Primary Outcomes (1)

• Change From Baseline in Peri-Implant Marginal Bone Level at Final Follow-up

  Vertical distance (mm) from the bone crest to the first implant thread, measured at the mesial and distal sites on standardized periapical radiographs (long-cone paralleling technique) with calibrated ImageJ software by two blinded examiners. Change is calculated as the baseline value minus the follow-up value; positive values indicate bone loss.

  Baseline (prosthesis delivery), 6 months after loading, and final follow-up (12 to 24 months after loading)

Secondary Outcomes (2)

• Interleukin-1β Concentration in Peri-Implant Crevicular Fluid

  12 months after loading

• Matrix Metalloproteinase-8 Concentration in Peri-Implant Crevicular Fluid

  12 months after loading

Study Arms (2)

Tissue-level implant, crestal placement

ACTIVE COMPARATOR

Klockner Essential Cone tissue-level implants (1.5 mm machined transmucosal collar, conical connection) placed with the treated surface at the crestal level and restored with monolithic zirconia single crowns.

Device: issue-level implant placed at crestal level (Klockner Essential Cone)

Bone-level implant, 2 mm subcrestal placement

EXPERIMENTAL

Klockner Vega bone-level implants (internal hexagon with 10° conical interface and platform switching) placed 2 mm subcrestally. A definitive 2 mm transepithelial abutment was connected 2 months after surgery and was never removed (one-abutment-one-time protocol). Restored with monolithic zirconia single crowns.

Device: Bone-level implant placed 2 mm subcrestally with one-abutment-one-time protocol (Klockner Vega)

Interventions

issue-level implant placed at crestal level (Klockner Essential Cone) DEVICE

Tissue-level dental implant with a 1.5 mm machined transmucosal collar and conical connection, placed with the treated surface at the level of the bone crest after flap elevation.

Tissue-level implant, crestal placement

Bone-level implant placed 2 mm subcrestally with one-abutment-one-time protocol (Klockner Vega) DEVICE

Bone-level dental implant with an internal hexagonal connection, 10° conical interface and platform switching, placed 2 mm below the bone crest. A definitive 2 mm transepithelial abutment was connected 2 months after surgery and never removed.

Bone-level implant, 2 mm subcrestal placement

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults in good general health
• Missing one or more back teeth that can be replaced with a dental implant
• Healthy gums, with no active gum disease
• Good oral hygiene (plaque and gum bleeding scores below 20%)
• Enough jawbone to place an implant at least 4 mm wide and 8 mm long, with at least 1.5 mm of bone around the implant, as confirmed by a 3D dental scan (CBCT)

You may not qualify if:

• Smoking
• Uncontrolled diabetes
• Treatment with intravenous bisphosphonates (bone-strengthening drugs given by injection)
• Weakened immune system or treatment with immunosuppressive drugs
• Active cancer
• Previous radiotherapy to the head or neck
• Pregnancy
• Untreated gum disease (periodontitis)
• Insufficient jawbone quality or quantity

Sponsors & Collaborators

• Markel Diéguez-Pereira: lead
• Sociedad Española de Prótesis Estomatológica (SEPES): collaborator

Study Sites (1)

Clinica Dental MD

Bilbao, Bizkaia, 48012, Spain

Location

MeSH Terms

Conditions

Alveolar Bone Loss

Condition Hierarchy (Ancestors)

Bone Resorption; Bone Diseases; Musculoskeletal Diseases; Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The two radiographic outcome assessors and the laboratory staff who performed the ELISA analyses were blinded to group allocation. The surgeon was aware of the allocation, as the implant type was assigned at the surgical planning stage, and blinding of the care provider was not possible because the implants differ visibly in design and placement depth.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: DDS, PhD; Collaborating Professor, Master's Degree in Prostodhontics, Oral Implantology and Periodontology, Universidad Europea Miguel de Cervantes

Model Details: Parallel-group design with randomization at the implant level (coin toss). Patients receiving more than one implant could receive implants of both configurations.

Study Record Dates

• First Submitted: October 14, 2026
• First Posted: October 21, 2026
• Study Start: May 2, 2022
• Primary Completion: November 6, 2024
• Study Completion: November 6, 2024
• Last Updated: October 21, 2026

Record last verified: 2026-10

Locations

ES (1)