Trial Outcomes & Findings for Mandibular Overdenture Clinical Trial Comparing Parallel Sided and Tapered Dental Implants (NCT NCT03272828)

NCT ID: NCT03272828

Last Updated: 2024-01-09

Results Overview

Implant failure defined as an implant that has lost osseointegration and no longer is stable and supported by the surrounding bone (no bone to implant contact).

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

48 participants

Primary outcome timeframe

From implant placement (baseline) to 5 years

Results posted on

2024-01-09

Participant Flow

Participants were recruited via flyers posted in the School of Dentistry. A total of 63 people were screened for eligibility and 48 met the inclusion criteria.

Of 48 eligible participants who signed the consent form and were enrolled in the study, one declined study participation due to lack of willingness to pay for the required cone beam computed tomography (CBCT) pre-surgical procedure. Participants were randomized to implant group the day of surgery.

Participant milestones

Participant milestones
Measure
Parallel Sided Implant Group
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Overall Study
STARTED
24
23
Overall Study
COMPLETED
13
13
Overall Study
NOT COMPLETED
11
10

Reasons for withdrawal

Reasons for withdrawal
Measure
Parallel Sided Implant Group
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Overall Study
Lost to Follow-up
7
7
Overall Study
Withdrawal by Subject
2
0
Overall Study
Deceased
1
1
Overall Study
Failed implant
1
2

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Parallel Sided Implant Group
n=24 Participants
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
n=23 Participants
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Total
n=47 Participants
Total of all reporting groups
Age, Continuous
61.17 years
n=24 Participants
61.74 years
n=23 Participants
61.45 years
n=47 Participants
Sex: Female, Male
Female
15 Participants
n=24 Participants
11 Participants
n=23 Participants
26 Participants
n=47 Participants
Sex: Female, Male
Male
9 Participants
n=24 Participants
12 Participants
n=23 Participants
21 Participants
n=47 Participants
Race and Ethnicity Not Collected
0 Participants
Race and Ethnicity were not collected from any participant.
Region of Enrollment
United States
24 Participants
n=24 Participants
23 Participants
n=23 Participants
47 Participants
n=47 Participants
Implant stability quotient (ISQ)
82.75 units on a scale
STANDARD_DEVIATION 2.75 • n=24 Participants
81.30 units on a scale
STANDARD_DEVIATION 3.65 • n=23 Participants
82.04 units on a scale
STANDARD_DEVIATION 3.27 • n=47 Participants

PRIMARY outcome

Timeframe: From implant placement (baseline) to 5 years

Population: All participants who had an implant placed at the midline of the mandibular arch and their mandibular denture fitted for immediate wearing.

Implant failure defined as an implant that has lost osseointegration and no longer is stable and supported by the surrounding bone (no bone to implant contact).

Outcome measures

Outcome measures
Measure
Parallel Sided Implant Group
n=24 Participants
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
n=23 Participants
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Difference in Implant Failure Rate Between Parallel Sided and Tapered Dental Implants at 5 Years
1 Participants
2 Participants

SECONDARY outcome

Timeframe: 5 years

Population: Participants continuing in the study at 5 years

The implant stability quotient (ISQ) value is a measurement of the mechanical implant stability in the bone and is measured directly after surgical implant placement and then at follow-ups. It is obtained by resonance frequency with a device that sends out a signal to a metal rod placed in the implant and then reads the value of the signal when it bounces back. The value ranges from 0 to 100 with higher values indicating better bone-to-implant contact and greater stability.

Outcome measures

Outcome measures
Measure
Parallel Sided Implant Group
n=13 Participants
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
n=13 Participants
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Implant Stability Quotient (ISQ) Measured at 5 Years
80.77 units on a scale
Standard Deviation 5.82
85.54 units on a scale
Standard Deviation 6.50

SECONDARY outcome

Timeframe: From implant placement (baseline) to 5 years

Population: Participants continuing in the study at 5 years

The measure of bone loss in millimeters (mm) around the implant at 5 years compared to bone height at baseline. Changes in bone level are measured on intraoral radiographs and compared with the bone level measure immediately after surgical implant placement (baseline). The implant platform was used as the reference point and measurements of the bone were made to the nearest thread. The bone level is measured on both sides (mesial \& distal) of the implant using the thread on the implant as reference. The distance between the threads is 0.6 mm.

Outcome measures

Outcome measures
Measure
Parallel Sided Implant Group
n=13 Participants
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
n=13 Participants
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Bone Loss Measurement at 5 Years
1.02 millimeters
Standard Deviation 1.37
0.65 millimeters
Standard Deviation 1.08

Adverse Events

Parallel Sided Implant Group

Serious events: 0 serious events
Other events: 2 other events
Deaths: 1 deaths

Tapered Shaped Implant Group

Serious events: 0 serious events
Other events: 2 other events
Deaths: 1 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Parallel Sided Implant Group
n=24 participants at risk
A Parallel sided titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Tapered Shaped Implant Group
n=23 participants at risk
A tapered shaped titanium dental implant will be placed in the edentulous mandible. Nobel Biocare titanium dental implants
Gastrointestinal disorders
Implant failure
4.2%
1/24 • 5 years
8.7%
2/23 • 5 years
Psychiatric disorders
Participant wanted implant removed
4.2%
1/24 • 5 years
0.00%
0/23 • 5 years

Additional Information

Dr. Mats Kronstrom

University of Washington

Phone: 425-877-7345

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place