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NCT Number: NCT04713800

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

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.

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Key information

Conditions

Jaw, Edentulous, Partially Anodontia Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Jaw Diseases Jaw, Edentulous Missing Teeth Mouth Diseases Mouth, Edentulous Musculoskeletal Diseases Stomatognathic Diseases Stomatognathic System Abnormalities Tooth Abnormalities Tooth Diseases

Age range

22 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Geneva

Geneva, 1211, Switzerland

Location status: Recruiting

Location contact

João Pitta, Dr

CONTACT

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

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

Device

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.

Other names: Straumann® Variobase® for crown

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

Device

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.

Other names: Straumann® Gold abutment for crown

Primary outcomes

  1. Technical complication rate

    Time frame: 5 years

    assessed by USPHS-criteria

Secondary outcomes

  1. Survival rate

    Time frame: 1, 3, 5 years

  2. Biological parameters

    Time frame: 1, 3, 5 years

    assessed 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)

  3. Wear rate of restoration and antagonist

    Time frame: 1, 3, 5 years

    assessed by a volumetric analysis software

  4. Patient Reported Outcomes Measures (PROMs)

    Time frame: 1, 3, 5 years

    assessed 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]

  5. Cost-efficiency

    Time frame: single-point measure at baseline

    assessed by measuring time and counting costs of materials between the two workflows procedures (digital vs. analogue)

  6. Accuracy of fabrication

    Time frame: single-point measure at baseline

    measured in terms of occlusal adjustment needed between the two fabrication procedures (digital vs. analogue workflow)

  7. Operator Reported Outcomes Measures

    Time frame: single-point measure at baseline

    assessed 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]

Study contacts

Contact information is provided by the study sponsor or research team.

João Pitta, Dr

CONTACT

[email protected]

+41223794088

Sponsors and collaborators

Lead sponsor

University of Geneva, Switzerland

Other

Collaborators

  • ITI Foundation

Registry information

Official study title

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

Acronym: Cantilever

Important dates

Study start
2021
Primary completion
2027
Study completion
2027
First posted
Jan 19, 2021
Registry last updated
Nov 23, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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