Dentistry, Public Health, Environmental and Occupational Health, Rehabilitation
15
Scopus Publications
Scopus Publications
Does Aging Affect PolyJet™ 3D-Printed Teeth for Endodontics? A Micro-CT Evaluation Cláudia Barbosa, Tiago Reis, José B. Reis, Margarida Franco, Catarina Batista, et al. Journal of Functional Biomaterials, 2026 This study aimed to evaluate the aging effect (6 and 12 months), relative to baseline (0 months), on the dimensional accuracy, morphological stability, and shaping behavior of PolyJet™ 3D-printed teeth (3DPT) produced in two printing orientations (X and Y axes). Specimens (XA0, XA6, XA12, YA0, YA6, YA12) were analyzed using microcomputed tomography before and after root canal preparation with the ProTaper Gold® system. Preoperative analysis included canal volume, centroid, total tooth volume, and total tooth area. Aging-related changes were observed, with significant differences between XA0 and XA12 (p 0.05). These findings indicate that X-axis specimens are not comparable over time, while Y-axis specimens maintain baseline consistency. Postoperative evaluation revealed significant differences across aging conditions for most endodontic preparation parameters. Within the limitations of this study, aging had a limited effect on dimensional accuracy but influenced the shaping behavior of 3DPT. Based on these findings, future studies using PolyJet™ 3DPT should report the printing batch and the storage time between fabrication and experimental use, as these factors may influence the comparability and reliability of the results.
Does experience matter? Evaluating canal preparation time in straight and curved canals Tiago Reis, Hiba El Haj Sassi, Fadi Al Kafri, M. Conceição Manso, Sandra Gavinha, et al. Endodontology, 2026 Aim: Evaluate the influence of operator experience on glide path and root canal preparation times using three nickel-titanium systems across different preparation philosophies, in both straight and curved canals: A rotary system with variable taper, ProTaper Gold ® , a rotary system with constant taper, EndoGal ® , and a single-file reciprocating system, WaveOne Gold ® . Methods: Sixty straight and 60 curved canals were prepared by one experienced and one non-experienced operator following manufacturers’ protocols. Each operator prepared one group ( n = 10) of straight canals and one group ( n = 10) of curved canals, with each system, in a total of six groups by each operator. Instrumentation time was recorded using a digital stopwatch, which measured only the active time of file rotation inside the canal. Results: Glide path preparation times differed significantly among systems and between operators ( P 0.05). ProTaper Gold ® required the longest preparation times (39.1–87.3 s) and showed the greatest operator-related variability, while EndoGal® demonstrated intermediate performance (24.1–54.9 s). Conclusion: These findings, consistent with the existing literature, suggest that reciprocating single-file systems may improve procedural efficiency and reduce technique sensitivity, making them particularly suitable for novice operators in controlled clinical settings such as undergraduate dental clinics, supporting the inclusion of rotary and reciprocating instruments in undergraduate endodontic curricula.
Does Printing Orientation Matter in PolyJet 3D Printed Teeth for Endodontics? A Micro-CT Analysis Cláudia Barbosa, Tiago Reis, José B. Reis, Margarida Franco, Catarina Batista, et al. Journal of Functional Biomaterials, 2025 This study aimed to identify the optimal printing orientation (X, Y, or Z axis) and positioning of a mandibular molar presenting an isthmus using PolyJet™ technology. The influence of these parameters on dimensional accuracy and on the behavior of 3D-printed teeth (3DPT) during endodontic preparation with ProTaper Gold® system was evaluated. Six groups (XA, XB, YA, YB, ZA, ZB; n = 10) were printed with different axis orientations and distinct isthmus positions relative to the build platform. All samples underwent micro-computed tomography scanning before and after endodontic preparation. Regarding preoperative analyses—canal volume, centroids, and total tooth volume and area—no significant differences were found between groups XA–YA or XB–YB (p > 0.05), supporting their comparability. In contrast, groups ZA and ZB differed significantly from all others (p < 0.05), failing to meet equivalence required for further comparison, and were therefore excluded. Postoperative evaluation—volume change, centroid displacement, transportation, and unprepared areas—revealed no significant differences between XA–YA and XB–YB. Within the limitations of this study, both printing orientation and position affected the accuracy and repeatability of 3DPT, with positioning exerting the greatest influence, while their behavior towards endodontic preparation remained consistent across orientations.
Is Generalized Joint Hypermobility Associated with Chronic Painful Temporomandibular Disorders in Young Adults? A Cross-Sectional Study Cláudia Barbosa, Sandra Gavinha, Tânia Soares, Tiago Reis, Conceição Manso Journal of Clinical Medicine, 2025 Background/Objectives: Generalized joint hypermobility (GJH) is a common condition characterized by an increased range of motion across multiple joints. Previous studies have suggested a possible association between GJH and temporomandibular disorders (TMDs). This study aimed to assess the prevalence of GJH in a Portuguese population of young university adults and to explore the relationship between GJH, temporomandibular joint (TMJ) symptoms/clinical findings, chronic painful TMDs, and chronic painful TMDs subtypes (myalgia, arthralgia, or combined myalgia and arthralgia). Methods: A cross-sectional study was carried out in Oporto university institutions, involving 1249 students (18–25 years). GJH was assessed using the Beighton score cut-off ≥ 4. TMJ symptoms and clinical findings were collected using the Research Diagnostic Criteria for TMD protocol, as well as TMD diagnoses. Univariate and multivariate analyses were carried out to examine the associations between GJH and the variables of interest. Results: The overall prevalence of GJH was 41.9%, with females exhibiting a significantly higher likelihood of GJH (p < 0.001). A statistically significant association was found between GJH and TMJ clicking (p < 0.05). Although no overall association was found between GJH and chronic painful TMDs, GJH was significantly associated with the combined diagnosis of myalgia and arthralgia (p < 0.05). Conclusions: The results suggest that GJH may be associated with the more complex subtypes of chronic painful TMDs. However, due to the small size effect of this association, future longitudinal studies with large samples using GJH broader diagnostic criteria are essential to elucidate the relationship between GJH and painful TMDs in asymptomatic nonsyndromic joint hypermobility populations.
Surface Roughness of Polyetheretherketone Printed by Fused Deposition Modeling: A Pilot Study Investigating the Impact of Print Layer Thickness and Polishing Method Tânia Soares, Carlos Fernandes, Cláudia Barbosa, Mário A. P. Vaz, Tiago Reis, et al. Applied Sciences Switzerland, 2024 Polyetheretherketone is a high-performance thermoplastic polymer that can be used in 3D printing by fused deposition modeling, and is a promising material for dental applications. Some printing parameters are sensitive and can influence the properties of the printed object. Thus, this work aims to evaluate the influence of the print layer thickness on the surface roughness of polyetheretherketone before and after polishing and to verify the effectiveness of the polishing method used, as well as to compare it with the results obtained using polymethyl methacrylate as the control group. Specimens with different impression layer thicknesses were printed with polyetheretherketone (Group A—0.1 mm and Group B—0.3 mm). Additionally, a control group with polymethyl methacrylate specimens was milled. Roughness evaluation was conducted using a contact profilometer after the specimens had been printed (before polishing). Then, silicon carbide sandpaper was used to polish the surface, and the roughness was reassessed. Differences were observed between specimens regarding the print layer thickness and the roughness, with the 0.3 mm layer thickness showing the lowest roughness values. The results of this pilot study suggest that the surface roughness of fused deposition modeling printed polyetheretherketone is influenced by print layer thickness, with the lowest roughness seen at a thickness of 0.3 mm.
Three-Dimensional Printed Teeth in Endodontics: A New Protocol for Microcomputed Tomography Studies Tiago Reis, Cláudia Barbosa, Margarida Franco, Ruben Silva, Nuno Alves, et al. Materials, 2024 This study aimed to describe a support material removal protocol (SMRP) from inside the root canals of three-dimensional printed teeth (3DPT) obtained by the microcomputed tomography (microCT) of a natural tooth (NT), evaluate its effectiveness by comparing the 3DPT to NT in terms of internal anatomy and behaviour toward endodontic preparation, and evaluate if 3DPT are adequate to assess the differences between two preparation systems. After the SMRP, twenty 3DPT printed by PolyJet™ were microCT scanned before preparation and thereafter randomly assigned into two groups (n = 10). One group and NT were prepared using ProTaper Gold® (PTG), and the other group with Endogal® (ENDG). MicroCT scans were carried out after preparation, and the volume increase, volume of dentin removed, centroids, transportation, and unprepared areas were compared. For the parameters evaluated, no significant differences were found between the 3DPT and NT before and after preparation (p > 0.05), and no significant differences were found between the 3DPT PTG group and the 3DPT ENDG group (p > 0.05). It can be concluded that the SMRP described is effective in removing the support material SUP706B™. PolyJet™ is adequate for printing 3DPT. Furthermore, 3DPT printed with high-temperature RGD525™ have similar behaviour during endodontic preparation with PTG as the NT, and 3DPT can be used to compare two preparation systems.
Root Canal Preparation of a Commercial Artificial Tooth versus Natural Tooth—A MicroCT Study Tiago Reis, Cláudia Barbosa, Margarida Franco, Catarina Batista, Nuno Alves, et al. Applied Sciences Switzerland, 2023 This study aimed to evaluate by microCT the preparation of the artificial teeth (ATs), TrueTooth®, versus natural teeth (NTs): (1) the time and number of pecking movements needed for preparation; (2) the root canal volume increase; (3) if the pulp-colored medium has any effect on the 3D analysis. Material and Methods: Artificial and natural maxillary molars were used. Fourteen AT distobuccal canals and fourteen NT buccal canals were used for the first and second aim and fourteen AT mesiobuccal canals for the third aim. Results: No statistically significant differences were observed regarding the time and number of pecking movements (p > 0.05); for the root canal volume increase, a statistically significant difference was observed (p < 0.05) with a higher mean value for NTs; however, in the group of ATs, there was a volume decrease in three cases. The AT mesiobuccal root canal mean volume increase was also negative. Conclusions: There are no differences between the time and number of pecking movements between NTs and ATs, so TrueTooth® can potentially be used in endodontic training. The volume increase between ATs and NTs was higher in NTs. However, some samples showed negative values, also seen in the AT mesiobuccal canal, confirming that the pulp-colored medium has an effect on the 3D analysis.
3D Resin-coated pressure sensor response for bite force assessment: A pilot study Tânia Soares, Marco Marques, Cláudia Barbosa, Mário Vaz, Maria Helena Figueiral Journal of Dental Research Dental Clinics Dental Prospects, 2023 Background. Occlusal splints with sensors help in the bruxism diagnosis and monitoring, by recording the patient’s bite force. The aim of this study was to evaluate the accuracy of a pressure sensor when it is covered with different thicknesses of a 3D printing resin (Anycubic 405nm Translucent Green UV Resin, Anycubic, UK). Methods. In this preliminary study, the evaluated sensor (FlexiForce A201 Sensor, Tekscan) was firstly calibrated without any type of cover material, and later tested with 3D printing resin with different thicknesses (1 mm, 1.15 mm, 1.4 mm and 1.6 mm). The load tests were performed by a force tester (MultiTest 2.5 dV, Mecmesin). Results. When the pressure sensor was covered with resin of 1mm and 1.6 mm thick specimens, a higher difference was found between the applied load and the corresponding sensor reading. Conclusion. It was concluded that it is possible to use this type of pressure sensor and that it showed better accuracy with the 1.15 mm and 1.4 mm 3D printing resin covering.
3D-Printed Teeth in Endodontics: Why, How, Problems and Future—A Narrative Review Tiago Reis, Cláudia Barbosa, Margarida Franco, Catarina Baptista, Nuno Alves, et al. International Journal of Environmental Research and Public Health, 2022 Three-dimensional printing offers possibilities for the development of new models in endodontics. Numerous studies have used 3D-printed teeth; however, protocols for the standardization of studies still need to be developed. Another problem with 3D-printed teeth is the different areas of literature requested to understand the processes. This review aims to gather evidence about 3D-printed teeth on the following aspects: (1) why they are advantageous; (2) how they are manufactured; (3) problems they present; and (4) future research topics. Natural teeth are still the standard practice in ex vivo studies and pre-clinical courses, but they have several drawbacks. Printed teeth may overcome all limitations of natural teeth. Printing technology relies on 3D data and post-processing tools to form a 3D model, ultimately generating a prototype using 3D printers. The major concerns with 3D-printed teeth are the resin hardness and printing accuracy of the canal anatomy. Guidance is presented for future studies to solve the problems of 3D-printed teeth and develop well-established protocols, for the standardization of methods to be achieved. In the future, 3D-printed teeth have the possibility to become the gold standard in ex vivo studies and endodontic training.
