Clinical and Patient Outcomes of 4 mm Ultra-Short vs. 8 mm Implants With Bone Augmentation in the Back Upper Jaw

February 10, 2026 updated by: Universitat Internacional de Catalunya

Clinical- and Patient-related Outcomes of 4 mm Ultra-short Implants Compared to 8 Mm-long Implants With Bone Augmentation for the Rehabilitation of Posterior Atrophic Maxilla: a Randomized Controlled Clinical Trial.

This study aims to compare 2 different groups of patients with both a healed site in the upper posterior sector after extractions, one treated with ultra-short implants, and another with long implants with bone regeneration. The objective is to evaluate if short-implants are superior in terms of better clinical outcomes, survival rates and safety, reduced surgical time, postoperative discomfort, and complication risk compared to conventional implants and bone regeneration.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
35

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

inclusion criteria:

  • Inform consent signed.
  • Adult patients (≥18 years old).
  • No pregnant women or without the desire to stay.
  • Periodontal and peri-implant health in a pristine or reduced periodontium.
  • Full mouth plaque score < 20% (O'Leary, 1972)
  • Maxillary multiple posterior maxillary healed sites at least 4 months after extraction (with antagonist teeth with a good prognosis (Lindhe et al. 2008)) presenting ≥ 6.5 mm of bone width and 5-6 mm in height from the bone crest to the floor of the sinus.
  • Need for a multiple splinted implant supported restoration with distal adjacent teeth or distal free-end in the posterior maxilla

exclusion criteria

  • Patients with uncontrolled systemic diseases.
  • Smoker patients (≥10 cig/day).
  • Patients taking medications that affect bone metabolism or immunologic disorders.
  • Patients allergic to penicillin.
  • Patients presenting acute or chronic maxillary sinus lesions.
  • Advanced vertical crestal bone atrophy in the posterior maxilla (Type V and IV, Cawood-Howell Classification)
  • Vertical space of < 6 mm for a screw-retained implant restoration.
  • Patients referring allergy to titanium or to any component of the implant/restoration.
  • No previous attempts of implant installation in the same surgical site.
  • Pregnant or lactating women.
  • Patients willing to start or in course of an orthodontic therapy.

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: ultra-short implants
4mm long implants
Device: Ultra short implants
Placement of an ultra short implant of 4mm in the posterior atrophic maxilla without any bone regeneration procedure
Other: long implants with bone augmentation
8mm long implants after transcrestal sinus floor elevation with bone augmentation
Device: Long implants with bone augmentation
Placement of long implants of 8mm in the posterior atrophic maxilla alongside bone augmentation

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Satisfaction of the surgical procedure
Time Frame: The day of the intervention after the surgery is finalized
The patient is gonna make a subjective assessment of satisfaction of the surgery once it is finished. For that, we are going to use a 10 centimeter visual analog scale. The extremes of the scale are the extreme expressions of satisfaction, where the extreme left represents a 0 (not satisfied) and 10 (very satisfied). The patient won't have numbers between 0-10 so he will not be influenced by them. Wherever he marks, we will measure it and it will represent in centimeters how was his satisfaction
The day of the intervention after the surgery is finalized

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Surgical time
Time Frame: at the day of the intervention, since the administration of the anesthesia until the placement of the last suture knot
elapsed time since the administration of local anesthesia until the placement of the last suture knot, with a scale of the exact minutes
at the day of the intervention, since the administration of the anesthesia until the placement of the last suture knot
Pain Intensity
Time Frame: Since the day of the intervention once the surgery is finalized , until the 7th day after the surgery, each day of the following 7 days
Subjective assessment of pain intensity using a 10-cm visual analog scale. The extremes of the scale are the extreme expressions of pain
Since the day of the intervention once the surgery is finalized , until the 7th day after the surgery, each day of the following 7 days
Rescue medication
Time Frame: After the surgery during the next 7 days
The need to intake rescue medication of Ibuprofen 600mg, Paracetamol 650mg or Amoxicilin 500mg with a nominal response of Yes or No
After the surgery during the next 7 days
Intra-surgical complications
Time Frame: The day of the surgery
Any undesired event that happens during the surgical procedure, for example, profuse bleeding, Schneider membrane perforation, by a categorical nominal answer Yes or No
The day of the surgery
Post-surgical complications
Time Frame: 7 days after the surgery
Any undesired event that happens during the first week of healing
7 days after the surgery
Implant survival
Time Frame: From 10 weeks after surgery to 36 months, after restoration delivery
If the implant is present in the mouth regardless of the biological or technical complications. An implant will be considered as failed if explantation is needed for the following reasons: (i) lateral, vertical mobility or rotation; (ii) drastic decrease in the ISQ values over time; (iii) discomfort or pain; and (iv) peri-implant radiolucency compatible with fibrointegration. It will be evaluated in a categorical nominal answer Yes or No
From 10 weeks after surgery to 36 months, after restoration delivery
Marginal bone level changes
Time Frame: The day of the surgery, 12 months after and 36 months after
distance from the mucosal margin to the base of the peri-implant pocket as measured with a PCP UNC 15 periodontal probe. By a mm scale
The day of the surgery, 12 months after and 36 months after
Probing pocket depth
Time Frame: 12 months after surgery and 36 months after surgery
distance from the mucosal margin to the base of the peri-implant pocket as measured with a PCP UNC 15 periodontal probe. Scale in mm.
12 months after surgery and 36 months after surgery
Bleeding on probing
Time Frame: 12 months and 36 months after surgery
: presence or absence of bleeding when performing the peri-implant probing. By a categorical nominal answer Yes or No
12 months and 36 months after surgery
Suppuration on probing
Time Frame: 12 months and 36 months after surgery
Presence or absence of suppuration when performing the peri- implant probing. By a categorical nominal answer Yes or No
12 months and 36 months after surgery
Keratinized mucosa width
Time Frame: 12 months and 36 months after surgery
distance from the mucogingival line to the peri-implant mucosal margin in the buccal site as measured with a PCP UNC 15 periodontal probe. In a mm scale
12 months and 36 months after surgery
Soft tissue dehiscence
Time Frame: 12 months and 36 months after surgery
exposure of any of the abutment or implant components, by a categorical nominal answer Yes or No
12 months and 36 months after surgery
Prosthetic complications
Time Frame: 12 months and 36 months after surgery
Any undesired event in the prosthetic component (abutment or crown), for example, screw loosening, ceramic chipping
12 months and 36 months after surgery

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Age
Time Frame: The day of the inform consent and selection period and 7 days after the surgery
Elapsed time from the birthdate until the date of intervention assignment. Expressed in exact years.
The day of the inform consent and selection period and 7 days after the surgery
Gender
Time Frame: The day of the inform consent and selection period
male/female. Expressed as absolute and relative frequency.
The day of the inform consent and selection period
Smoking habit
Time Frame: The day of inform consent and selection period
Non-smoker, Smoker ≤ 10 cig per day or Former smoker. Expressed as absolute and relative frequencies.
The day of inform consent and selection period
Bone density
Time Frame: The day of the surgery
Subjective evaluation during drilling. Type I, II, III, IV (Lekhom and Zarb, 1986). Expressed as absolute and relative frequencies.
The day of the surgery
Full mouth plaque score
Time Frame: 12 months and 36 months after surgery
Proposed by O'Leary in 1972. Expressed as relative frequency.
12 months and 36 months after surgery
Full mouth bleeding score
Time Frame: 12 months and 36 months after surgery
Proposed by Ainamo and Bay in 1975. Expressed as relative frequency.
12 months and 36 months after surgery
Crown to implant ratio
Time Frame: 6 months after surgery
Relationship between the crown and the implant length. Measured in periapical radiographs. Expressed as mean and SD/median or IQR.
6 months after surgery
Implant position
Time Frame: The day of Informed consent
1st or 2nd molar. Expressed as absolute and relative frequency.
The day of Informed consent
Primary & secondary implant stability
Time Frame: The day of the surgery and 10 weeks after surgery
Based on a resonance frequency analysis (with ISQ values). Expressed as means and SD /median and IQR.
The day of the surgery and 10 weeks after surgery
Vertical soft tissue height
Time Frame: The day of the surgery
Measured with a PCP UNC 15 periodontal probe as the distance from the bone crest to the most coronal portion of keratinized tissue once the buccal flap is raised. Expressed as means and SD /median and IQR.
The day of the surgery

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Universitat Internacional de Catalunya

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 (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 20, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 14, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PER-ECL-2024-07

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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