A Prospective Clinical Trial Evaluating Outcomes of Surveyed Zirconia Crowns

NCT06564337 | Not Yet Recruiting

• 1 other identifier: 00042791
• Study Type: interventional
• Target: 50
• Locations: 0 countries
• Sites: N/A

Brief Summary

Zirconia has shown to be a suitable substitute for metal ceramic crowns when comparing survival, biological and technical complications. Evidence demonstrating the outcomes of surveyed zirconia crowns on removable partial denture abutments is unavailable. Zirconia as a substitute for metal ceramic is being currently used for fabricating surveyed crowns although quantitative data evaluating its efficacy is sparse. The purpose of this prospective clinical trial is to evaluate clinical outcomes when zirconia is used as a full coverage restoration on removable partial denture abutments. The study will be designed as a 3-5 year prospective observational trial in the University of Toronto undergraduate clinic in a controlled environment. Outcomes measures will include survival, biological and technical complications. Descriptive statistics will be used to summarize patient characteristics and outcomes and for categorical variables frequency and percentages will be reported. A level of significance 0.05 will be used for inferential analysis, with p-values \< 0.05 reported as statistically significant. It is expected that zirconia will demonstrate similar outcomes to traditional metal ceramic surveyed crowns.

Conditions

Removable Partial Denture; Dental Crown

Keywords

removable partial denture abutment; monolithic zirconia crown survival; surveyed zirconia crown

Outcome Measures

Primary Outcomes (5)

• Survival

  A. Survival will be recorded as the tooth with the crown still in function with or without 'clinical complications' during and up to the end of follow up. These will include but are not limited to * occlusal adjustments, * follow up sensitivity, * open margins, * recurrent decay, * infection, * endodontic treatment or retreatment, * chipping of ceramic, * recementation, * non healing endodontic lesion, * bone loss and associated periodontal problems.

  study follow up- every year for 3-5 years

• Biological Complications

  Biological failures will be recorded when the tooth is no longer present in the mouth either because of * tooth or core fracture rendering the tooth non restorable, * or the tooth extracted because of caries, infection or periodontal disease.

  study follow up- every year for 3-5 years

• Technical Complications

  Technical failures will be recorded when * the zirconia crown fractures or * needs to be replaced because of inadequate fit.

  study follow up- every year for 3-5 years

• Success

  Success will be recorded as all surviving crowns with no clinical complications.

  study follow up- every year for 3-5 years

• Other complications

  Not listed above

  study follow up- every year for 3-5 years

Study Arms (1)

Patients recruited for intervention

EXPERIMENTAL

A combination of 3Y-TZP and 5Y-TZP (IPS e.max ZirCAD Prime, Ivoclar AG) with a flexural strength of 1200MPa will be utilized for the crowns. Tooth preparation will include occlusal reduction of 1.0 to 1.2mm and rounded line angles for the rest seats within the zirconia crown and buccal and lingual reduction of 1 to 1.5mm to allow for adequate buccal and lingual contour to accommodate retentive clasp arms and minor connectors. Impressions for zirconia crowns will be made with polyvinyl siloxane on a full arch custom tray. After clinical verification crowns will be cemented with resin or resin modified glass ionomer cement

Device: Surveyed zirconia crown

Interventions

Surveyed zirconia crown DEVICE

Patient recruitment will be from the patient population that presents to the undergraduate dental clinic requiring removable dental prosthesis (RPD) to replace missing teeth. Selection of abutment teeth for zirconia surveyed crowns will be similar to that currently utilized when selecting RPD abutments to be restored with either porcelain fused to metal or full metal surveyed crowns for tissue and tooth supported RPD's.

Patients recruited for intervention

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• In Kennedy Class 1 and 2 tisuue supported RPD's-Terminal abutments 3,4,5,6
• In Kennedy Class 3 and 4 tooth supported RPD's- any abutment teeth selected will need to be documented if selected as abutments for a surveyed crown.
• Selection of abutment teeth for zirconia surveyed crowns will be similar to that currently utilized when selecting cast RPD abutments to be restored with either porcelain fused to metal or full metal surveyed crowns for tissue and tooth supported cast RPD's. Identifiable data will include:
• RPD abutment teeth which may benefit from full coverage due to large restorations.
• Posterior endodontically treated teeth with inadequate marginal ridge support and
• Abutment teeth which require axial modification for RPD retentive and or stability elements.
• In situations where esthetic improvement is desirable
• Reasons for selection wil be documented.

You may not qualify if:

• Crowns that need to be splinted; patients that decline a surveyed crown; patients under the age of 18 years; patients that decline to participate in the study.

Sponsors & Collaborators

• Neena DSouza: lead
• University of Toronto: collaborator

Related Publications (9)

• Kois DE, Isvilanonda V, Chaiyabutr Y, Kois JC. Evaluation of fracture resistance and failure risks of posterior partial coverage restorations. J Esthet Restor Dent. 2013 Apr;25(2):110-22. doi: 10.1111/jerd.12018. Epub 2013 Mar 19.

  PMID: 23617385 BACKGROUND

• Goto M, Oki K, Koyano K, Ayukawa Y. The 3-year cumulative survival rates of posterior monolithic zirconia crowns and their antagonist teeth, and their influencing factors. J Oral Sci. 2022 Oct 1;64(4):286-289. doi: 10.2334/josnusd.22-0221. Epub 2022 Sep 14.

  PMID: 36104182 BACKGROUND

• Burns DR, Unger JW. The construction of crowns for removable partial denture abutment teeth. Quintessence Int. 1994 Jul;25(7):471-5.

  PMID: 7991768 BACKGROUND

• Turner CH, Smith BJ. The use of crowns to modify abutment teeth of removable partial dentures. 2. Clinical and laboratory procedures. J Dent. 1979 Jun;7(2):98-104. doi: 10.1016/0300-5712(79)90002-2. No abstract available.

  PMID: 379070 BACKGROUND

• Behr M, Kolbeck C, Lang R, Hahnel S, Dirschl L, Handel G. Clinical performance of cements as luting agents for telescopic double crown-retained removable partial and complete overdentures. Int J Prosthodont. 2009 Sep-Oct;22(5):479-87.

  PMID: 20095198 BACKGROUND

• Kopzon V, Raedel M. Outcomes of abutment teeth with double crowns over an observation period of 27 years. J Prosthodont Res. 2023 Oct 13;67(4):518-523. doi: 10.2186/jpr.JPR_D_22_00165. Epub 2022 Dec 17.

  PMID: 36529501 BACKGROUND

• Igarashi Y, Goto T. Ten-year follow-up study of conical crown-retained dentures. Int J Prosthodont. 1997 Mar-Apr;10(2):149-55.

  PMID: 9206455 BACKGROUND

• Sorensen JA, Martinoff JT. Endodontically treated teeth as abutments. J Prosthet Dent. 1985 May;53(5):631-6. doi: 10.1016/0022-3913(85)90008-3. No abstract available.

  PMID: 3889302 BACKGROUND

• D'Souza NL, Jutlah EM, Deshpande RA, Somogyi-Ganss E. Comparison of clinical outcomes between single metal-ceramic and zirconia crowns. J Prosthet Dent. 2025 Feb;133(2):464-471. doi: 10.1016/j.prosdent.2024.02.028. Epub 2024 Apr 4.

  PMID: 38580582 BACKGROUND

Study Officials

• Eszter S Ganss, DDS

  Faculty of Dentistry, University of Toronto

  STUDY CHAIR

Central Study Contacts

Neena L D'SOUZA, DDS

CONTACT

4163996121; neena.dsouza@dentistry.utoronto.ca

Greg S Anderson, DDS

CONTACT

4168648189; greg.anderson@dentistry.utoronto.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Co-Investigator

Model Details: Research data on the survival of zirconia crowns as RPD abutments is limited although anecdotally these are being used regularly by dentists in clinical practice. To our knowledge a clinical trial evaluating the outcomes of surveyed monolithic zirconia crowns as RPD abutments has not been investigated previously. We propose to evaluate the outcomes of surveyed zirconia crowns as RPD abutments in a prospective trial and compare the survival, biological and technical complications with alternative materials historically used for surveyed crowns.

Study Record Dates

• First Submitted: August 18, 2024
• First Posted: August 21, 2024
• Study Start: January 6, 2025
• Primary Completion (Estimated): December 18, 2026
• Study Completion (Estimated): December 31, 2031
• Last Updated: August 23, 2024

Record last verified: 2024-08

Data Sharing

• IPD Sharing: Will not share