Direct Versus Indirect Endocrowns on Endodontically Treated Molars (Endocrowns)

A Randomised Clinical Study on Indirect Lithium Disilicate Versus Direct Composite Restorations in Severely Compromised Endodontically Treated Molar Teeth

In this clinical trial the performance of monolithic restorations made of indirect lithium disilicate ceramic and direct resin composite materials on severe structurally compromised endodontically treated molar teeth is evaluated.

Rationale: It is presumed that indirect restoration of extensively restored endodontically treated molar teeth contributes to durability. However, there is a lack of evidence concerning the performance of both indirect ceramic and direct composite monolithic restorations. Such restorations are commonly named 'endocrowns'.

Objective: The objective of the study is to investigate which treatment modality, indirect ceramic or direct composite endocrowns, provide the best restoration of severe structurally compromised endodontically treated molar teeth in terms of clinical performance.

Study design: Randomised 5-year clinical trial with endodontically treated molar teeth restored with either indirect glass ceramic (experimental) or direct resin composite endocrowns (control).

Study population: A total of 102 severe structurally compromised endodontically treated molar teeth that need to be restored, with a maximum of two restorations per patiënt. Patients are healthy volunteers over 18 years.

Intervention: Each patiënt with a restorative indication for endodontically treated first and second molar teeth will be randomly assigned to one of two treatment groups: indirect glass ceramic endocrown or direct composite endocrown.

Study Overview

• Status: Active, not recruiting
• Conditions: Endodontically-Treated Teeth; Composite Resins; Restoration of Posterior Teeth; Endocrown Restoration
• Intervention / Treatment: Device: Composite resin; Device: lithium disilicate endocrown

Detailed Description

In this clinical trial the performance of monolithic restorations made of indirect lithium disilicate ceramic and direct resin composite materials on severe structurally compromised endodontically treated molar teeth is evaluated.

Rationale: It is presumed that indirect restoration of extensively restored endodontically treated molar teeth contributes to durability. However, there is a lack of evidence concerning the performance of both indirect ceramic and direct composite monolithic restorations. Such restorations are commonly named 'endocrowns'.

Objective: The objective of the study is to investigate which treatment modality, indirect ceramic or direct composite endocrowns, provide the best restoration of severe structurally compromised endodontically treated molar teeth in terms of clinical performance.

Study design: Randomised 5-year clinical trial with endodontically treated molar teeth restored with either indirect glass ceramic (experimental) or direct resin composite endocrowns (control).

Study population: A total of 102 severe structurally compromised endodontically treated molar teeth that need to be restored, with a maximum of two restorations per patiënt. Patients are healthy volunteers over 18 years.

Intervention: Each patiënt with a restorative indication for endodontically treated first and second molar teeth will be randomly assigned to one of two treatment groups: indirect glass ceramic endocrown or direct composite endocrown.

• Study Type: Interventional
• Enrollment (Actual): 102
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

ASA i or II [de Jong, 1994], This ASA score is already known before participation, due to regular check-ups.

• Asymptomatic endodontically treated and heavily restored upper and lower molar teeth with an indication for a (new) restoration.
• Pulp chamber height of at least 2 millimeters.
• Need of cuspal coverage;
• Pockets around the molar 3-5 mm.
• Moderate to low caries risk.

Exclusion Criteria:

• ASA III or higher.

  • Pockets around the molar >5mm.
  • Presence of an accessible furcation.
  • No biological width present (3mm).
  • Rubber dam placement not possible.
  • No antagonistic tooth.
  • History of severe parafunction.
  • High caries risk.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Direct composite resin endocrown; Direct restoration with a microhybrid composite resin	Device: Composite resin; Direct composite resin restoration after application of an adhesive system
Experimental: Lithium disilicate endocrown; Indirect restoration with a lithium disilicate endocrown in conjunction with Immediate Dentin Sealing	Device: lithium disilicate endocrown; Lithium disilicate endocrown in conjunction with Immediate Dentin Sealing

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Restoration survival	Failure is defined as restoration replacement or tooth extraction due to secondary decay or vertical root fracture (FDI scre 5). A FDI score of 4 or less indicates survival.	5 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Abutment tooth survival	Failure defined as tooth extraction, regardless of cause.	5 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Abutment tooth success	failure was defined as tooth extraction, the presence of endodontic pathology, or the necessity for (non-)surgical endodontic retreatment	5 years
Patient satisfaction	Patient satisfaction measured on VAS-scale (0-100)	1 and 5 years

Collaborators and Investigators

• Sponsor: University Medical Center Groningen
• Investigators: Study Director: Marco S. Cune, Prof.dr., Department of Restorative Dentistry and Biomaterials - Center for Dentistry and Oral Hygiene - University Medical Center Groningen

Study record dates

Study Major Dates

• Study Start (Actual): October 12, 2015
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): November 1, 2028

Study Registration Dates

• First Submitted: April 11, 2025
• First Submitted That Met QC Criteria: April 11, 2025
• First Posted (Actual): April 18, 2025

Study Record Updates

• Last Update Posted (Actual): April 18, 2025
• Last Update Submitted That Met QC Criteria: April 11, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: composite resin; endocrown; endocrown restoration; direct composite; endodontically-treated teeth
• Additional Relevant MeSH Terms: Stomatognathic Diseases; Dental Pulp Diseases; Tooth Diseases; Tooth, Nonvital; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Central Nervous System Depressants; Tranquilizing Agents; Psychotropic Drugs; Antidepressive Agents; Antimanic Agents; Lithium Carbonate
• Other Study ID Numbers: 201500425

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Start before 2019 with the inclusion and was not mentioned in informed consent forms specifically

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No