Direct Versus Indirect Endocrowns on Endodontically Treated Molars

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.

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.