Clinical Performance and Fit of 3D-Printed Versus Milled Endocrowns: An 18-Month Trial

NCT07708077 | Not Yet Recruiting DMC

• 1 other identifier: RECO6U/14-2026
• Study Type: interventional
• Target: 52
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn whether 3D-printed resin composite endocrowns perform as well as milled resin composite endocrowns in restoring endodontically treated teeth. It will also learn how well the restorations fit over time. The main questions it aims to answer are: Do 3D-printed endocrowns and milled endocrowns show different clinical performance? Do 3D-printed endocrowns and milled endocrowns differ in restoration fit over 18 months? Researchers will compare two fabrication methods: Additive manufacturing: 3D-printed resin composite endocrowns. Subtractive manufacturing: milled resin composite endocrowns. Participants will: Be recruited from the Conservative Dentistry Department, Faculty of Dentistry, October 6 University. Receive tooth preparation after confirmation of satisfactory root canal treatment. Have their teeth prepared using standardized endocrown guidelines by one calibrated operator. Have digital scans taken of the prepared tooth, opposing arch, and bite registration. Have restorations designed digitally and then assigned randomly to one of the two groups. Receive a temporary restoration until the final endocrown is ready. Have the final restoration tried in for fit, contacts, and occlusion before cementation. Have a baseline post-cementation scan taken for fit assessment. Return for follow-up visits at baseline, 6 months, 12 months, and 18 months. Be evaluated at each visit using Modified FDI criteria and 3D digital superimposition for fit analysis.

Conditions

Clinical Performance of Endodontically Treated Teeth Restored With Endocrowns; Restoration Fit of Endodontically Treated Teeth With Endocrowns

Keywords

3D-printed endocrown, Milled endocrown, Biomimetic resin composite, Endodontically treated molar, Clinical performance, Restoration fit and 18-month follow-up.

Outcome Measures

Primary Outcomes (1)

• Clinical performance

  World Dental Federation (FDI) criteria set to evaluate direct and indirect dental restorations: Hickel et al. (2023). Aesthetic properties of Endocrown restorations (Domain A): 1. Surface Luster 2. Staining (surface, margin) 3. color match and translucency 4. Esthetic anatomical form Functional performance of Endocrown restorations (Domain F): 5. Fracture of material and retention 6. Marginal adaptation 7. Approximal anatomical form Biological Properties of Endocrown restorations (Domain B): 8. Recurrence of caries (CAR) 9. Tooth integrity (enamel cracks, tooth fracture) 10. Periodontal response

  T0=baseline (1st week), T1=6 months, T2=12 months and T3=18 months follow-up.

Secondary Outcomes (1)

• Restoration Fit

  T0=baseline (1st week), T1=6 months, T2=12 months and T3=18 months follow-up.

Study Arms (2)

Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.

OTHER

Subtractive Manufacturing, the control group will utilize restorations fabricated via subtractive manufacturing, specifically by milling from industrially fabricated blocks of nanohybrid composite. This method is the established gold standard for producing CAD/CAM resin composite restorations. It is known for creating restorations with excellent mechanical properties, high density, and predictable clinical performance due to the optimized, industrial-grade polymerization of the blocks. These materials, which include polymer-infiltrated ceramic networks (PICNs) and resin nanoceramics, were developed to combine the favorable properties of both ceramics and resin composites, offering a biomimetic alternative to traditional glass-ceramics.

Other: Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.; Other: Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturing

Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturi

OTHER

Additive Manufacturing, the intervention group will feature restorations fabricated via 3D printing. This technology is more time and cost-efficient, more accurate, and could provide a considerable alternative to the currently applied CNC milling, reduced material waste, and the ability to create complex geometries with high precision. Recent studies have shown that 3D-printed restorations can achieve promising results in terms of marginal and internal fit, which are critical for clinical longevity. This has spurred the development of novel, ceramic-filled hybrid materials specifically engineered for permanent 3D-printed restorations. Manufacturers of these materials claim high dimensional stability, flexural strength, and a modulus suitable for definitive restorations (e.g., Bego; VarseoSmile Triniq technical product data sheet). However, there is a lack of clinical data to support these claims.

Other: Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.; Other: Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturing

Interventions

Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks. OTHER

Subtractive Manufacturing, the control group will utilize restorations fabricated via subtractive manufacturing, specifically by milling from industrially fabricated blocks of nanohybrid composite. This method is the established gold standard for producing CAD/CAM resin composite restorations. It is known for creating restorations with excellent mechanical properties, high density, and predictable clinical performance due to the optimized, industrial-grade polymerization of the blocks. These materials, which include polymer-infiltrated ceramic networks (PICNs) and resin nanoceramics, were developed to combine the favorable properties of both ceramics and resin composites, offering a biomimetic alternative to traditional glass-ceramics.

Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.; Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturi

Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturing OTHER

Additive Manufacturing, the intervention group will feature restorations fabricated via 3D printing. This technology is more time and cost-efficient, more accurate, and could provide a considerable alternative to the currently applied CNC milling, reduced material waste, and the ability to create complex geometries with high precision. Recent studies have shown that 3D-printed restorations can achieve promising results in terms of marginal and internal fit, which are critical for clinical longevity. This has spurred the development of novel, ceramic-filled hybrid materials specifically engineered for permanent 3D-printed restorations. Manufacturers of these materials claim high dimensional stability, flexural strength, and a modulus suitable for definitive restorations (e.g., Bego; VarseoSmile Triniq technical product data sheet). However, there is a lack of clinical data to support these claims.

Milled resin composite restorations fabricated using subtractive manufacturing from CAD/CAM blocks.; Three dimensionally (3D) printed resin composite restorations fabricated using additive manufacturi

Eligibility Criteria

• Age: 20 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• \- Patient-Related Criteria
• Age: Between 20 and 40 years.
• Oral Hygiene: Good oral hygiene, evidenced by low plaque and gingival index scores.
• Willingness to attend regular follow-up visits during the study period
• \- Tooth-Related Criteria
• Endodontic Quality: High-quality root canal treatment with no clinical or radiographic signs of pathology.
• Tooth Type: A permanent molar tooth requiring an endocrown after successful root canal treatment.
• Located in functional occlusion and opposing natural teeth in stable occlusal contact with the restored tooth.
• Teeth free from cracks, fractures, or internal resorption; supporting tissues without structural defects that may compromise restoration success

You may not qualify if:

• \- Patient-Related Criteria
• Parafunctional Habits: Severe bruxism, clenching, or other parafunctional habits.
• Allergies: to any study materials (e.g., resin composites, bonding agents).
• Patients with systemic diseases contraindicate elective dental treatment (e.g., uncontrolled diabetes)
• \- Tooth-Related Criteria
• Insufficient Tooth Structure: Less than 2mm of circumferential sound denting height or deep, unrestorable.
• Tooth opposes prosthetic restoration.
• Teeth with a history of fixed prosthetic restorations (previous crowns, inlays/onlays, or bridge restorations)
• Periodontal Issues: Active periodontal disease, excessive mobility (\> Grade 1, or a hopeless long-term prognosis.

Sponsors & Collaborators

• October 6 University: lead

Study Sites (1)

October city, October 6 university

Giza, 12556, Egypt

Location

Related Publications (2)

• 7. Cal, I. K., Ozturk, F., Aydin, N., & Karaoglanoglu, S. (2024). 3D Printed Restorations Produced From Permanent Resin: Case Report. International Dental Journal, 74, S298. 10.1016/j.identj.2024.07.282 8. Doumit, M., Beuer, F., Böse, M. W. H., Unkovskiy, A., Hey, J., & Prause, E. (2025). Wear behavior of 3D printed, minimally invasive restorations: Clinical data after 24 months in function. The Journal of Prosthetic Dentistry, 134(3), 662-669. 10.1016/j.prosdent.2025.03.014 9. Güntekin, N., & Tunçdemir, A. R. (2024). Comparison of volumetric loss and surface roughness of composite dental restorations obtained by additive and subtractive manufacturing methods. Heliyon, 10(4). 10.1016/j.heliyon.2024.e26269 10. Hickel, R., Mesinger, S., Opdam, N., Loomans, B., Frankenberger, R., Cadenaro, M., . & Kühnisch, J. (2023). Revised FDI criteria for evaluating direct and indirect dental restorations-recommendations for its clinical use, interpretation, and reporting. Clinical oral investigations, 27(6), 2573-2592. 10.1007/s00784-022- 04814-1 11. Kader, İ. T., Özer, S., & Arıcan, B. (2025). The effect of different fit-indicating materials and preparation designs on the marginal and internal fit of 3D-printed permanent endocrowns. Meandros Medical And Dental Journal, 26(1), 108-116. 10.69601/meandrosmdj.1596545 12. Koyuturk, A. E., Ozmen, B., Tokay, U., Tuloglu, N., Sari, M. E., & Sonmez, T. T. (2013). Two-year follow-up of indirect posterior composite restorations of permanent teeth with excessive material loss in pediatric patients: a clinical study. Journal of Adhesive Dentistry, 15(6). 10.3290/j.jad.a30897 13. Mahran, G. A., El-Banna, A., & El-Korashy, D. I. (2025). Evaluation of a 3Dprinted nanohybrid resin composite versus a milled resin composite for flexural strength, wear and color stability. BMC Oral Health, 25(1), 572. https://doi.org/10.1186/s12903-025-05861-2

  RESULT

• 1.Abad-Coronel, C., Durán Urdiales, D., Benalcázar Arias, M. V., Córdova, A. K., Medina, M. S., & Bravo Torres, W. (2025). Flexural strength, fatigue behavior, and microhardness of three-dimensional (3D)-printed resin material for indirect restorations: A systematic review. Materials, 18(3), 556. https://doi.org/10.3390/ma18030556 2. Abou-steit, S. S., Salem, M. A., Omar, S., & Mahmoud, N. (2024). Clinical evaluation of the biomimetic aspect in the restoration of endodontically treated teeth (Randomized clinical trial). Egyptian Dental Journal, 70(3), 2683-2693. 10.21608/EDJ.2024.291267.3045 3. Abuabboud, O., Marinescu, A. G., Paven, M., Kovacs, I. M., Nica, L. M., Faur, A. B., & Jivănescu, A. (2025). Influence of Cement Thickness, Dentine Thickness, and Intracoronal Depth on the Fracture Resistance of 3D-Printed Endocrowns: A Pilot In Vitro Study. Dentistry Journal, 13(6), 263. 10.3390/dj13060263 23 4. Albrecht, M., Schmidt, F., Menzel, F., Yassine, J., Beuer, F., & Unkovskiy, A. (2024). Comparative Analysis of Modern 3D-Printed Hybrid Resin-Ceramic Materials for Indirect Restorations: An In Vitro Study. Polymers,16(22), 3161. https://doi.org/10.3390/polym16223161 5. Alghauli, M. A., & Alqutaibi, A. Y. (2024). 3D-printed intracoronal restorations, occlusal and laminate veneers: Clinical relevance, properties, and behavior compared to milled restorations; a systematic review and meta-analysis. Journal of Esthetic and Restorative Dentistry, 36(8), 1153-1170. 10.1111/jerd.13228 6. Arslan, S., Karagön, M., Balkaya, H., & Köse, B. (2024). A randomized clinical study evaluating the 30-month clinical performance of class II indirect restorations in endodontically treated teeth using ceramic, hybrid, and composite computer-aided design/computer-aided production blocks. Journal of Conservative Dentistry and Endodontics, 27(1), 68-75. 10.4103/JCDE.JCDE_213_23

  RESULT

Study Officials

• Mohsen Hussein Abielhassan, • Professor, Conservative Dent

  October 6 University

  STUDY DIRECTOR

Central Study Contacts

Yara Ahmed Elgammal, Assistant Lecturer

CONTACT

+201157564592; yara.elgammal.dent@o6u.edu.eg

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant lecturer, Conservative Dentistry Department, Faculty of Dentistry, October 6 University, Egypt.

Study Record Dates

• First Submitted: July 12, 2026
• First Posted: July 16, 2026
• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): November 1, 2028
• Study Completion (Estimated): December 1, 2028
• Last Updated: July 21, 2026

Record last verified: 2026-07

Locations

EG (1)