Titanium Zirconium (TiZr) Mini Implants

Is the Stabilization of a Mandibular Overdenture Employing Four Novel One-piece Immediately Loaded TiZr Implants With Miniaturized Stud-type Attachments a Feasible Alternative to Two Two-piece Early Loaded Tissue-level Implants With Regular Stud-type Attachments?

H0: "Within the first year post-placement, four interforaminally placed, immediately loaded 2.4 mm narrow-diameter one-piece TiZr implants with miniaturized stud-type attachments show improved patient-reported outcome measures (PROMS) compared to two interforaminally placed, early loaded, TiZr two-piece implants with stud-type attachments to retain a mandibular overdenture."The specific aim is to compare both treatment alternatives to evaluate which one may be recommended for elderly edentulous patients.

Study Overview

• Status: Active, not recruiting
• Conditions: Dental Implants
• Intervention / Treatment: Procedure: early loading; Procedure: immediate loading

• Study Type: Interventional
• Enrollment (Actual): 72
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Bern, Switzerland, 3010
    • University of Bern
  • Canton of Bern
    • Langenthal, Canton of Bern, Switzerland, 4900
      • Private Practice Dr. B. Wallkamm

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• At patient level:

  • Written informed consent
  • Age ≥ 18 years
  • Sufficient complete dentures (Marxkors and Ferger, 1989) not older than 1 year
  • Patient is unsatisfied with mandibular denture to the degree that he/she seeks treatment

• At site level:

  • Healed edentulous mandible (minimum 8 weeks since last extraction)
  • Minimal ridge dimensions 5.5 mm (width) by 12 mm (height) in the anterior (interforaminal) area, allowing the placement of 3.3 (endosseous diameter) by 10 mm (length) implants
  • Opposing dentition: complete denture on a edentulous maxilla
  • Physical status (PS) 1 and 2 (American Society of Anesthesiologists)

Exclusion Criteria:

• At patient level

  • Any physical or mental disorder that would interfere with the ability to perform adequate oral hygiene or the capability of providing written informed consent and compliance to the protocol
  • Any disorder that would interfere with wound healing or represent a contraindication for oral surgery such as, but not limited to, uncontrolled diabetes or conditions resulting in or requiring immunosuppression, radiation, chemotherapy, frequent use of antibiotics or antiresorptive medication such as bisphosphonates
  • Pregnancy or lactation
  • Heavy smoking habit with > 20 cig/d
  • Severe bruxism or clenching habits, present oro-facial pain

• At site level:

  • Ridge defects requiring staged bone augmentation procedures (simultaneous Guided Bone Regeneration (GBR) within the ridge contour allowed)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Control-group; Two Tissue Level TiZr Sand blasted long grit acid-etched (SLA) implants placed in positions 33 and 43 (diameter 3.3mm, length ≥10mm), early loading	Procedure: early loading; two TiZr implants on SLA surface
Experimental: Experimental-group; Four narrow-diameter implants (NDI) TiZr SLA implants in positions 34, 32, 42, and 44 (diameter 2.4mm, length ≥10mm), immediate loading	Procedure: immediate loading; four TiZr implants on SLA surface

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Geriatric Oral Health Assessment Index (GOHAI)	Change from baseline questionnaires in Oral Health Related Quality of Life (OHRQoL). Scores 0-60: higher values represent lower OHRQoL	One-year follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Additional Oral Health Impact Profile for edentulism (OHIP-EDENT)	Change from baseline questionnaires	Follow-up (up to 365 days)
Additional PROM Denture Satisfaction Index (DSI)	Change in Denture Satisfaction higher values represent better satisfaction (0-1200mm)	Baseline, follow-up (up to 365 days)
Implant Survival	Survival (yes/no)	at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up
Implant Success	Success according to Misch (2007) Misch criteria scores 1-4: higher values represent better success	at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up
Prosthetic Survival	Prosthetic Survival (yes/no): is the denture still in place?	Baseline, follow-up (up to 365 days)
Chewing Efficiency	Color mixing test	Baseline, follow-up (up to 365 days)
Plaque Index	Plaque Index Scores 0-3 3= thick plaque is visible along gingival margin 2= plaque is visible along gingival margin, with or without air drying 1= following air drying, plaque is not visible but can be wiped off with an explorer 0= following air drying, plaque is not visible nor can be wiped off with an explorer	at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up
Bleeding Index	Bleeding Index Scores 0-3 0= Healthy gingival; Gingival look inflamed, but don't bleed when probed; Gingival look inflamed and bleed when probed; Ulceration and spontaneous bleeding	at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up
Pocket Probing depth	depth measured in mm	at implant loading (at 24 hours for arm B, at 6-8 weeks for arm A), at the one-year follow-up
Time-Cost-Analysis	Total treatment time will be collected and added. Total treatment cost will be evaluated and a ratio will be calculated. The groups will be compared on the base of this ration	After surgery, after implants loading, after follow-up (up to 365 days)
Cost Effectiveness and Willingness to Pay	Cost effectiveness wil be calculated as a ratio of treatment cost in relation to change of GOHAI sum score. This will allow to evaluate how much monetary item is needed to achieve a change in GOHAI	Total change and time at 1y follow-up
In-vivo evaluated loss of retentive force	Measurement with a hand-held digital force gauge	after implant loading (expected to be after 6 weeks on average) and at follow-up (up to 365 days)

Collaborators and Investigators

• Sponsor: University of Bern
• Investigators: Principal Investigator: Beat Wallkamm, Dr, Private Practice; Study Director: Martin Schimmel, Prof, University of Bern

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2019
• Primary Completion (Actual): September 10, 2024
• Study Completion (Estimated): August 1, 2033

Study Registration Dates

• First Submitted: January 30, 2019
• First Submitted That Met QC Criteria: February 6, 2019
• First Posted (Actual): February 12, 2019

Study Record Updates

• Last Update Posted (Actual): February 18, 2026
• Last Update Submitted That Met QC Criteria: February 16, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Surgical Procedures, Operative; Prosthesis Implantation; Dentistry; Oral Surgical Procedures; Prosthodontics; Dental Implantation, Endosseous; Dental Implantation; Oral Surgical Procedures, Preprosthetic; Immediate Dental Implant Loading
• Other Study ID Numbers: Mini 1286_2018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: It is not planned to use the data of this study for future research.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No