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Journal of Polymer & Composites Review Article Special issue

Comparative Analysis of the Structural Integrity and Dimensional Stability of Additively Manufactured Biopolymers vs. Thermoformed PETG: A 1-Year Retrospective Study on Polymer Performance in Orthodontic Applications

  1. Sujitha Suresh Saveetha Dental College and Hospitals, Saveetha Institute of medical and technical Sciences, Saveetha University, Chennai
  2. Remmiya Mary Varghese Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha university, Chennai
  3. Parthiban Saketharaman Department of periodontics, Sri Venkateswaraa dental College Ariyur
  4. Mounica Dommeti Department of Orthodontics and dentofacial Orthopedics, Ragas Dental College & Hospital, Uthandi, Chennai
  5. V.S. Kumar Bhagavathula Department of Oral and Maxillofacial Surgery, Konaseema institute of Dental sciences
  6. Gadde Harika Department of Orthodontics and Dentofacial Orthopedics, SIBAR Institute of dental sciences, Guntur

Abstract

Objective: This study aimed to evaluate the long-term dimensional accuracy and structural performance of direct 3D-printed biopolymers compared to conventional vacuum-formed Polyethylene Terephthalate Glycol (PETG) composites. The investigation focused on how different polymer processing methods (additive manufacturing vs. thermoforming) influence material thinning and resistance to occlusal stress.

Methods: A retrospective analysis was conducted on 60 cases (n = 60) of post-orthodontic maintenance. The sample was divided into two cohorts: Group A (n = 30), utilizing additively manufactured (3D-printed) biopolymer retainers (0.75 mm); and Group B (n = 30), utilizing vacuum-formed PETG (0.75 mm). Polymer stability was quantified at two time points (T_0 and T_1) using digital surface mapping to measure changes in arch dimensions (inter-canine and inter-molar width). Material degradation and internal stress manifestations (thinning and micro-fractures) were assessed via high-resolution intraoral imaging and clinical structural audits.

Results: Preliminary data indicate that while both polymer systems provided sufficient arch stability, Group A demonstrated superior dimensional consistency in the posterior segment (P 0.05), confirming equal functional efficacy despite differing physical properties.

Conclusions: Both 3D-printed biopolymers and PETG composites are effective for 1-year orthodontic retention. However, additive manufacturing provides enhanced structural integrity by bypassing the thermal degradation and mechanical thinning inherent in traditional thermoforming. This study verifies that designer polymer architectures created via 3D printing offer superior performance in high-wear biomedical applications

Keywords

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