Dental Restoration, Endodontically Treated Teeth, Tooth, Nonvital
Conditions
Brief summary
This randomized controlled trial (RCT) compares the 24-month clinical performance of endocrown restorations fabricated by two digital manufacturing pathways: additive manufacturing using 3D-printed ceramic-filled photopolymer resin (VarseoSmile TriniQ, BEGO) versus subtractive computer-aided design/computer-aided manufacturing (CAD/CAM) milling from hybrid nano-ceramic blocks (HC Hard Block, Shofu). Sixty endocrowns will be placed in endodontically treated posterior molars and evaluated using modified United States Public Health Service (USPHS) criteria at 6, 12, and 24 months. The trial is conducted at the Conservative Dentistry Department, Faculty of Dentistry, Cairo University.
Detailed description
Post-endodontic rehabilitation of extensively damaged posterior molars using endocrowns represents a minimally invasive alternative to conventional crown-plus-post-and-core approaches. Digital fabrication has advanced both the precision and reproducibility of endocrown manufacture. While computer-aided design/computer-aided manufacturing (CAD/CAM) milled hybrid ceramic endocrowns are well-validated clinically, prospective clinical data comparing 3D-printed definitive restorations to milled counterparts are absent. This trial employs a parallel-group, 1:1 randomized design with triple blinding of participants, outcome assessors, and statistician. All restorations are delivered using Beautilink SA self-adhesive dual-cure resin cement. The primary outcome is fracture resistance at 24 months; secondary outcomes include retention, marginal adaptation, marginal discoloration, surface texture, anatomic form, color match, secondary caries, fabrication time, and patient satisfaction assessed by Visual Analogue Scale (VAS).
Interventions
DEVICECAD/CAM Milled HC Hard Block Endocrown
Endocrown restoration milled from HC Hard Block hybrid nano-ceramic (Shofu Inc., Japan) using a five-axis wet-milling CAD/CAM unit. Restoration designed with ExoCAD software, finished and glazed per manufacturer protocol, and cemented with Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
DEVICE3D-Printed VarseoSmile TriniQ Endocrown
Endocrown restoration 3D-printed using VarseoSmile TriniQ ceramic-filled photopolymer resin (BEGO GmbH \& Co. KG, Germany) on a 4K LCD printer at 30-45 degree build angle. Post-cured under nitrogen atmosphere, surface glazed, and cemented with Beautilink SA self-adhesive dual-cure resin cement (Shofu Inc., Japan).
Sponsors
Cairo University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Masking description
The treating clinician cannot be blinded due to visible differences between manufacturing workflows. Participants and outcome assessors are blinded to group allocation. The trial statistician is blinded to group assignment throughout analysis.
Eligibility
Sex/Gender
ALL
Age
25 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
* Age 25-45 years, male or female * Endodontically treated molar tooth with radiographically confirmed treatment success and no clinical signs of failure * Sufficient remaining coronal structure for endocrown preparation: minimum three walls, wall thickness 1.5 mm or greater, pulp chamber depth 3 mm or greater, supragingival preparation margins * Completely erupted tooth with intact periodontal support * Minimum of 20 occluding teeth * Satisfactory oral hygiene status * Capable of providing written informed consent and committed to scheduled follow-up visits
Exclusion criteria
* Diagnosed parafunctional habit or nocturnal bruxism * Uncontrolled systemic illness or physical disability precluding safe participation * Heavy tobacco use * Current or suspected pregnancy * Periapical disease or radiographic signs of endodontic failure * Evidence of pathological tooth wear or occlusal erosion * Moderate-to-severe periodontitis or tooth with hopeless prognosis * Radiographic or clinical evidence of vertical root fracture * Impaired decision-making capacity or anticipated non-compliance
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Restoration Fracture Resistance | 24 months | Assessed using modified USPHS criteria: Alpha = absence of fracture; Bravo = minor chip amenable to repair; Charlie = catastrophic fracture, unrestorable |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Retention | 6, 12, and 24 months | Modified USPHS: Alpha = in situ; Bravo = partial displacement; Charlie = complete loss |
| Marginal Discoloration | 6, 12, and 24 months | Modified USPHS: Alpha = absent; Bravo = superficial; Charlie = penetrating |
| Surface Texture | 6, 12, and 24 months | Modified USPHS: Alpha = smooth; Bravo = minor irregularities; Charlie = extensive breakdown |
| Anatomic Form | 6, 12, and 24 months | Modified USPHS: Alpha = conforms to natural contour; Bravo = discrepancy present, dentin intact; Charlie = dentin or base exposed |
| Color Match | 6, 12, and 24 months | Modified USPHS: Alpha = indistinguishable from adjacent tooth; Bravo = minor deviation, clinically acceptable; Charlie = obvious mismatch; Delta = gross color failure |
| Secondary Caries | 6, 12, and 24 months | Modified USPHS: Alpha = absent; Charlie = present |
| Fabrication Time | Periprocedural | Time in minutes from CAD design completion to restoration readiness for cementation |
| Patient Satisfaction | 6, 12, and 24 months | Visual Analogue Scale 0-100 mm; 0 = entirely dissatisfied, 100 = entirely satisfied |
Contacts
CONTACTDina Ez Mohamed, BDS MSc PhD
CONTACTRawda H Abdelaziz, BDS MSc PhD
Outcome results
None listed