A Comparative Study of the Structure-Property Relationships in CAD/CAM Milled vs. 3D-Printed High-Performance Polymers: Impact of Molecular Orientation on Abrasive Wear

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Year : 2026 | Volume : 14 | 04 | Page :
By

Aardra B S,

Vikas Singh,

Iknoor Kaur,

Remmiya Mary Varghese,

Parthiban Saketharaman,

Shubhangi Srivastava,

  1. Resident Intern, Department of Orthodontics , Saveetha Dental College and HospitalSaveetha Institute of Medical and Technical Sciences (SIMATS)Saveetha University, Chennai, Tamil Nadu, India
  2. Professor, Department of public health Dentistry, Teerthanker Mahaveer Dental College & Research Centre, Teerthanker Mahaveer University, Moradabad, Uttar Pradesh, India
  3. BDS/Certified Dental Assistant, Department of Dentistry , Brookside Dental Office 292 university Ave, Fredericton, NB E3A 1R9, Canada
  4. Associate Professor, Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS)Saveetha University, Chennai, Tamil Nadu, India
  5. Professor and HOD, Department of Periodontics, Tagore Dental College and Hospital, Rathinamangalam, Chennai, Tamil Nadu, India
  6. Senior Lecturer, Department of Prosthodontics, ITS Dental College, Ghaziabad, Uttar Pradesh, India

Abstract

Background: The transition from subtractive to additive manufacturing in prosthetic dentistry has introduced significant variations in the macromolecular architecture of high-performance polymers. While CAD/CAM milling utilizes high-density, industrially polymerized blocks, 3D printing (Additive Manufacturing) relies on layer-by-layer deposition, which may induce anisotropic molecular orientation. This retrospective study investigates how these distinct manufacturing “thermal histories” influence the long-term abrasive wear resistance of PEEK and PEKK restorations.

​Materials and Methods: Data were retrospectively analyzed from a cohort of 120 clinical cases (2021–2025) involving posterior crowns fabricated via either CAD/CAM milling (n=60) or Digital Light Processing (DLP) 3D printing (n=60). Archival material characterization data, including X-ray Diffraction (XRD) for crystallinity index and Differential Scanning Calorimetry (DSC) for glass transition temperature (T_g), were correlated with retrospective clinical wear measurements. Surface degradation was quantified using digitized occlusal wear maps generated from sequential intraoral scans at 12, 24, and 36-month intervals.

​Results: Retrospective XRD analysis revealed a significantly higher degree of crystallinity in milled specimens (35% pm 2%) compared to 3D-printed counterparts (22% pm 4%). The 3D-printed polymers exhibited anisotropic wear patterns, with maximum material loss occurring at the inter-layer interfaces. Milled polymers demonstrated a superior structure-property relationship, maintaining a stable Surface Free Energy and lower volumetric wear rates (Linear regression analysis confirmed a strong correlation (r^2 = 0.84) between the degree of molecular orientation and clinical abrasive resistance.

​Conclusion: The manufacturing process fundamentally dictates the mechanical performance of high-performance polymers. Subtractive milling preserves a more uniform macromolecular structure, leading to superior abrasive wear resistance. Conversely, the additive process introduces structural heterogeneity that accelerates surface degradation. These findings provide a framework for “Performance Verification” in the selection of digital workflows for load-bearing polymer composites.

Keywords: Abrasive Wear, Additive manufacturing, polyetheretherketone, high-performance polymers, X-ray Diffraction (XRD)

How to cite this article: Aardra B S, Vikas Singh, Iknoor Kaur, Remmiya Mary Varghese, Parthiban Saketharaman, Shubhangi Srivastava. A Comparative Study of the Structure-Property Relationships in CAD/CAM Milled vs. 3D-Printed High-Performance Polymers: Impact of Molecular Orientation on Abrasive Wear. Journal of Polymer & Composites. 2026; 14(04):-.
How to cite this URL: Aardra B S, Vikas Singh, Iknoor Kaur, Remmiya Mary Varghese, Parthiban Saketharaman, Shubhangi Srivastava. A Comparative Study of the Structure-Property Relationships in CAD/CAM Milled vs. 3D-Printed High-Performance Polymers: Impact of Molecular Orientation on Abrasive Wear. Journal of Polymer & Composites. 2026; 14(04):-. Available from: https://journals.stmjournals.com/jopc/article=2026/view=251850

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Ahead of Print Subscription Review Article
Volume 14
04
Received 20/07/2026
Accepted 05/08/2026
Published 06/08/2026
Publication Time 17 Days

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