Predictable Method for Restoring Endodontically Treated Teeth, Comparing Indirect and Direct Methods and Materials in Aesthetic Dentistry.

NCT07778563 | Not Yet Recruiting

• 1 other identifier: No. 2-PĒK-4/88/2025
• Study Type: interventional
• Target: 30
• Locations: 0 countries
• Sites: N/A

Brief Summary

The goal of this clinical study is to evaluate the long-term clinical performance and cost-effectiveness of different restorative approaches for endodontically treated teeth, with a particular focus on zirconia and glass-ceramic onlays cemented using different resin cementation protocols, as well as direct composite restorations produced using the injection moulding technique. The main questions it aims to answer are: Do zirconia onlays cemented with self-adhesive resin cement show comparable long-term clinical performance to those cemented with conventional adhesive resin cement? Does the choice of cement influence restoration survival, marginal integrity, discoloration, retention, and the occurrence of biological or technical complications? How do zirconia and glass-ceramic onlays compare with direct composite restorations produced using the injection moulding technique? Which treatment approach provides the best balance between clinical performance, cost-effectiveness, and patient satisfaction? The clinical study will include 30 patients requiring restoration of two endodontically treated teeth. A split-mouth design will be used for the indirect restorations, allowing direct comparison of two cementation protocols within the same patient and minimizing the influence of individual patient-related factors. Zirconia and glass-ceramic onlays will be cemented using either a conventional adhesive resin cement or a self-adhesive resin cement. A third group will receive direct composite restorations using the injection moulding technique. Patients will be followed clinically at baseline, 1 year, and 3 years. The evaluations will assess restoration survival and condition, including fractures, cracks, loss of retention, marginal integrity, and discoloration. The condition of the abutment teeth and periodontal tissues will also be assessed, including secondary caries, endodontic complications, probing depth, bleeding on probing, and gingival recession. Patient-reported outcomes, including satisfaction and well-being, will be evaluated using questionnaires. An initial in vitro phase will assess the influence of tooth surface pretreatment on the bond strength of self-adhesive resin cement after artificial aging. The results of this phase will be used to establish the most effective surface pretreatment protocol for the clinical study. This study is expected to provide clinically relevant data on the long-term performance of zirconia, glass-ceramic, and direct composite restorations, as well as the influence of different cementation protocols. By combining clinical outcomes with complication rates, treatment costs, cost-effectiveness, and patient-reported outcomes, the study may help identify predictable, simplified, and economically sustainable restorative approaches for endodontically treated teeth.

Conditions

Endodontically Treated Teeth Requiring Indirect Restorative Treatment

Keywords

Zirconia Onlays, Self-Adhesive Resin Cement, Endodontically Treated Teeth, Bond Strength, Surface Pretreatment, Clinical Performance

Outcome Measures

Primary Outcomes (1)

• Number of participants with restoration-related complications, including fracture, loss of retention, marginal defects, and discoloration

  At baseline, 1 year, and 3 years after restoration placement

Study Arms (3)

Zirconia onlay

OTHER

Procedure: Cementation with Panavia V5; Procedure: Cementation with Panavia SA

Glass-ceramic onlay

OTHER

Procedure: Cementation with Panavia V5; Procedure: Cementation with Panavia SA

Direct composite onlay

OTHER

Procedure: Injection moulding

Interventions

Cementation with Panavia V5 PROCEDURE

Dentist places an onlay on a root canal-treated molar using a multi-step conventional adhesive cement, following a standardized clinical protocol.

Glass-ceramic onlay; Zirconia onlay

Cementation with Panavia SA PROCEDURE

Dentist places an onlay on a root canal-treated molar using a self adhesive cement, following a standardized clinical protocol.

Glass-ceramic onlay; Zirconia onlay

Injection moulding PROCEDURE

Dentist do an injecting moulding composite direct restoration on a root canal-treated molar, following a standardized clinical protocol.

Direct composite onlay

Eligibility Criteria

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

You may qualify if:

• Have two endodontically treated molars suitable for restoration, allowing a split-mouth design for the indirect restorations (zirconia and glass-ceramic onlays).
• Have sufficient tooth structure circumferentially above the gingival margin to allow adequate isolation during restoration cementation.
• Have controlled periodontal disease and adequate periodontal health for participation.
• Have maxillary or mandibular molars that are in functional occlusion. Both smokers and non-smokers are eligible to participate. For the direct composite injection moulding group, one suitable endodontically treated molar per participant will be restored.

Sponsors & Collaborators

• Riga Stradins University: lead
• Kuraray Noritake Dental Inc.: collaborator
• Malmö University: collaborator

Related Publications (5)

• Blatz MB, Vonderheide M, Conejo J. The Effect of Resin Bonding on Long-Term Success of High-Strength Ceramics. J Dent Res. 2018 Feb;97(2):132-139. doi: 10.1177/0022034517729134. Epub 2017 Sep 6.

  PMID: 28876966 BACKGROUND

• Spitznagel FA, Prott LS, Hoppe JS, Manitckaia T, Blatz MB, Zhang Y, Langner R, Gierthmuehlen PC. Minimally invasive CAD/CAM lithium disilicate partial-coverage restorations show superior in-vitro fatigue performance than single crowns. J Esthet Restor Dent. 2024 Jan;36(1):94-106. doi: 10.1111/jerd.13169. Epub 2023 Nov 27.

  PMID: 38009505 BACKGROUND

• European Society of Endodontology developed by:; Mannocci F, Bhuva B, Roig M, Zarow M, Bitter K. European Society of Endodontology position statement: The restoration of root filled teeth. Int Endod J. 2021 Nov;54(11):1974-1981. doi: 10.1111/iej.13607. Epub 2021 Sep 3.

  PMID: 34378217 BACKGROUND

• Govare N, Contrepois M. Endocrowns: A systematic review. J Prosthet Dent. 2020 Mar;123(3):411-418.e9. doi: 10.1016/j.prosdent.2019.04.009. Epub 2019 Jul 26.

  PMID: 31353111 BACKGROUND

• Ghodsi S, Shekarian M, Aghamohseni MM, Rasaeipour S, Arzani S. Resin cement selection for different types of fixed partial coverage restorations: A narrative systematic review. Clin Exp Dent Res. 2023 Dec;9(6):1096-1111. doi: 10.1002/cre2.761. Epub 2023 Jul 10.

  PMID: 37427500 BACKGROUND

MeSH Terms

Conditions

Tooth, Nonvital

Interventions

Cementation

Condition Hierarchy (Ancestors)

Dental Pulp Diseases; Tooth Diseases; Stomatognathic Diseases

Intervention Hierarchy (Ancestors)

Investigative Techniques; Dental Bonding; Dentistry

Central Study Contacts

Sanita Grīnberga, DDS

CONTACT

+37127096767; sanita.griinberga@gmail.com

Una Soboļeva, Dr. med. prof.

CONTACT

una.soboleva@rsu.lv

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Masking Details: Patients: They may be unaware of which cement type is used on which tooth, if both teeth are treated similarly in appearance. Outcome Assessors / Evaluators: Ideally, the clinicians or researchers assessing restoration retention, complications, and satisfaction should be blinded to the cement type to reduce bias. Data Analysts / Statisticians: If possible, those analyzing the results should also be blinded to which group corresponds to which cement type until the analysis is complete.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: DSD

Study Record Dates

• First Submitted: August 18, 2026
• First Posted: August 21, 2026
• Study Start: August 18, 2026
• Primary Completion (Estimated): April 15, 2027
• Study Completion (Estimated): July 1, 2031
• Last Updated: August 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: 4 years
• Access Criteria: Access is partially restricted, individual request is needed upon request to protect copyrights.