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

Jaw, Edentulous, Partially Clinical Trial

— Cantilever  

Official 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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04713800
• Other study ID #: Cantilver study
• Status: Recruiting
• Phase: N/A
• Start date: July 28, 2021
• Est. completion date: July 2027

Study information

• Verified date: November 2022
• Source: University of Geneva, Switzerland
• Contact: João Pitta, Dr
• Phone: +41223794088
• Email: joao.pitta[@]unige.ch
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 38
• Est. completion date: July 2027
• Est. primary completion date: July 2027
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 22 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Anodontia
• Jaw, Edentulous
• Jaw, Edentulous, Partially
• Missing Teeth
• Tooth Loss

Intervention

Device:
• Monolithic 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.
• porcelain 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.

Locations

Country	Name	City	State
Switzerland	University of Geneva	Geneva

Sponsors (2)

Lead Sponsor	Collaborator
University of Geneva, Switzerland	ITI Foundation

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Technical complication rate	assessed by USPHS-criteria	5 years
Secondary	Survival rate		1, 3, 5 years
Secondary	Biological parameters	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)	1, 3, 5 years
Secondary	Wear rate of restoration and antagonist	assessed by a volumetric analysis software	1, 3, 5 years
Secondary	Patient Reported Outcomes Measures (PROMs)	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]	1, 3, 5 years
Secondary	Cost-efficiency	assessed by measuring time and counting costs of materials between the two workflows procedures (digital vs. analogue)	single-point measure at baseline
Secondary	Accuracy of fabrication	measured in terms of occlusal adjustment needed between the two fabrication procedures (digital vs. analogue workflow)	single-point measure at baseline
Secondary	Operator Reported Outcomes Measures	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]	single-point measure at baseline