Effects of Implant Placement Depth (4 mm Versus 6 mm) on Crestal Bone Stability in Immediate Implant Placement: A Clinical Study With 1-Year Post-Restorative Results

May 1, 2026 updated by: Tomas Linkevicius
The aim of a study was to analyze the effect of implant placement depth (4 mm versus 6 mm below the mid-facial gingival margin) on marginal bone loss (MBL) around implant and implant stability during immediate implant placement after tooth extraction. Clinical trial was conducted involving 35 patients requiring immediate implant placement after tooth extraction. Implants were placed either 4 mm (control group) or 6 mm (test group) below the mid-facial gingival margin. Primary outcome was deemed to be radiographic assessment of marginal bone level from periapical radiographs. Secondary outcome was implant stability quotient registration using resonance freaquency analyzer. The null hypothesis is that there is no significant difference in peri-implant marginal bone loss between implants placed at 4 mm depth versus 6 mm depth relative to the buccal gingival margin during immediate implant placement.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

35

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Lithuania
      • Kaunas, Lithuania
        • Lithuanian University of Health Sciences

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

1) age ≥ 18 years; (2) generally healthy individuals with no medical contraindications for implant surgery; (3) healthy soft tissue, indicated by bleeding on probing (BOP) < 20% and Plaque Index (PI) < 25%; (4) keratinized gingiva ≥ 2 mm, both buccally and lingually; (5) presence of molar or premolar in the upper or lower jaw; (6) implant primary stability ≥ 35 Ncm; (7) intact alveolar bone walls post-extraction; (8) one study implant per patient; and (9) signed informed consent with permission to utilize data for research purposes.

Exclusion Criteria:

(1) smoking (≥ 10 cigarettes/day); (2) history of uncontrolled periodontitis; (3) uncontrolled diabetes or alcoholism; (4) medications known to impair healing; and (5) implant primary stability < 35 Ncm.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 4 mm
Procedure: Implants were positioned 4 mm below the mid-facial gingival margin
Tooth was carefully extracted and implant was placed 4 mm below free gingival margin of the extracted tooth.
Experimental: 6 mm
Procedure: Implant was placed 6 mm below free gingival margin
Tooth was extracted and dental implant placed 6 mm below free gingival margin of the extracted tooth.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Marginal bone loss around dental implant
Time Frame: From implant restoration delivery till 1 year follow-up
From implant restoration delivery till 1 year follow-up

Secondary Outcome Measures

Outcome Measure
Time Frame
Implant stability quotient
Time Frame: After implant placement and after 4 months
After implant placement and after 4 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tomas Linkevicius

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 8, 2021

Primary Completion (Actual)

September 16, 2024

Study Completion (Actual)

September 16, 2024

Study Registration Dates

First Submitted

May 1, 2026

First Submitted That Met QC Criteria

May 1, 2026

First Posted (Actual)

May 8, 2026

Study Record Updates

Last Update Posted (Actual)

May 8, 2026

Last Update Submitted That Met QC Criteria

May 1, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • BEC-LSMU(R)-41

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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