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Two-unit Cantilever Implant Prostheses Made of Monolithic Zirconia or PFM

Randomized Controlled Clinical Trial of Two-unit Cantilever Implant Prostheses Made of Monolithic Zirconia on Titanium Base Abutments or Porcelain-fused to Metal on Gold Abutments

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04713800
Acronym
Cantilever
Enrollment
38
Registered
2021-01-19
Start date
2021-07-28
Completion date
2027-07-31
Last updated
2022-11-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Jaw, Edentulous, Partially, Missing Teeth

Keywords

Dental Implants, Cantilever, Titanium base, Dental abutment, Fixed dental prosthesis, Monolithic zirconia, Porcelain fused to metal

Brief summary

The aim of is to compare the survival rate and technical outcomes of cantilever implant-supported fixed denture prosthetics (cFDPs) made either out of monolithic zirconia bonded to a titanium base in a digital workflow, or porcelain fused-to metal using a gold abutment in a conventional workflow. In addition, biological outcomes, wear patterns, PROMs and time efficiency will be recorded. The null hypothesis is: the reconstruction type does not influence the survival rate and technical outcomes of 2-unit implant-supported cFDP.

Interventions

DEVICEMonolithic zirconia screw retained implant-supported cantilever reconstruction supported by titanium base abutments, in a full digital workflow (ZR-TiB)

In group ZR-TiB the implant impressions will be taken using an intra-oral scanner and the respective scanbody. The restorations will be manufactured by means of CAD/CAM procedures using monolithic zirconia. For sufficient aesthetics, the zirconia restorations can be manually veneered with veneering ceramic only at the buccal surface, while the occlusal surface will remain monolithic and will be high-gloss polished. The zirconia restorations will be extra-orally cemented onto titanium base abutments (Straumann® Variobase® for crown, Straumann AG), correctly polished and delivered to the patient, by screw-retention onto the implant.

DEVICEporcelain fused-to metal screw retained implant-supported cantilever reconstruction supported by a gold-abutment, in a conventional workflow (PFM-GA)

In group PFM-GA implant impression will be taken using a polyvinyl siloxane or polyether impression material in a conventional manner with the use of stock trays and corresponding impression copings. The framework will be manufactured by the lost wax-technique using a gold-abutment (Straumann® Gold abutment for crown, Straumann AG) and a gold-alloy. All metal frameworks will be manually veneered with veneering ceramic, polished and glazed, and delivered to the patient, by screw-retention onto the implant.

Sponsors

ITI Foundation
CollaboratorINDUSTRY
University of Geneva, Switzerland
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
22 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Minimal age of 22 years old. * No general medical condition which represents a contraindication to implant treatment * Good oral hygiene (PII ≤ 20%), and healthy periodontal tissues (BOP≤ 20%) * Two adjacent-teeth gap in posterior maxilla or mandible arch (first premolar, second premolar, first molar, second molar) with an osseointegrated regular or wide-diameter bone-level implant in a prosthetically correct position to allow occlusal screw-retention. Free-end edentulous gaps can also be included * Presence of antagonist occlusal units

Exclusion criteria

* Severe bruxism or clenching habits * Patients with inadequate oral hygiene or persistent intraoral infection * Women who are pregnant or breast feeding at the day of inclusion * Smokers exceeding 15 cigarettes / day, or equivalent; patients chewing tobacco * Unable or unwilling to cooperate for the trial period * Estimated cantilever crown mesial-distal length \> 10 mm * Estimated implant crown height (from implant platform to occlusal contact points) \> 15 mm

Design outcomes

Primary

MeasureTime frameDescription
Technical complication rate5 yearsassessed by USPHS-criteria

Secondary

MeasureTime frameDescription
Biological parameters1, 3, 5 yearsassessed by clinical examination by measuring with a periodontal probe: bleeding on probing (yes/no per site), pocket probing depth (mm), width of keratinized mucosa (mm), assessed by evaluation of standardized x-rays: marginal bone level changes (mm)
Wear rate of restoration and antagonist1, 3, 5 yearsassessed by a volumetric analysis software
Patient Reported Outcomes Measures (PROMs)1, 3, 5 yearsassessed through questionnaires: Oral Health Impact Profile (OHIP-14) to evaluate oral health-related quality of life \[0-4 for each of the 14 questions, where 4 represents the worst outcome\]; Visual Analogue Scales (VAS) to evaluate patient experience with the impression procedure \[0-10, where 10 represents the best outcome\]
Survival rate1, 3, 5 years
Accuracy of fabricationsingle-point measure at baselinemeasured in terms of occlusal adjustment needed between the two fabrication procedures (digital vs. analogue workflow)
Operator Reported Outcomes Measuressingle-point measure at baselineassessed through Visual Analogue Scales (VAS) to evaluate operator experience with the impression procedure and with the adjustment of the restoration \[0-10, where 10 represents the best outcome\]
Cost-efficiencysingle-point measure at baselineassessed by measuring time and counting costs of materials between the two workflows procedures (digital vs. analogue)

Countries

Switzerland

Contacts

Primary ContactJoão Pitta, Dr
joao.pitta@unige.ch+41223794088

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026