Security of 3D-printed polylactide acid piece sterilization in the operating room: a sterility test

Evaluating Osteogenic Cell Differentiation Efficacy in the Presence of Polylactide Samples With Varied Compositions for Bone Grafting: In Vitro Study

In oral implantology, surgeons often confront the need to improve alveolar bone quality and volume before implantation in patients with bone defects. Whereas guided bone regeneration with titanium meshes is a clinical gold standard for bone augmentation, mesh removal pre-implantation presents a drawback. This study explores biodegradable scaffolds as an alternative. The research investigates the impact of various compositions of customized bone-grafting scaffolds on proliferation and osteogenic differentiation processes in vitro. Plates (10 × 10 × 0.5 mm) were fabricated from polylactide (PLA), PLA with 15% hydroxyapatite nanoparticles (PLA/HA), and polylactide with glycolic acid copolymers (PLGA 60:40 and 85:15). Gingival fibroblasts assessed the influence of experimental samples on proliferation and osteogenic differentiation in a low-glucose medium. Osteogenic differentiation was induced, and alizarin red staining measured extracellular matrix calcification via spectrophotometry. Active proliferation of gingival fibroblasts occurred along scaffold edges during cultivation. Although cells proliferated with experimental samples, rates were lower than control cells. PLA/HA showed higher alizarin red staining intensity, indicating enhanced matrix calcification. Experimental samples (PLA, PLA/HA, PLGA 85:15, PLGA 60:40) supported cell proliferation at lower rates than control. PLA/HA demonstrated increased matrix calcification. Biodegradable membranes were nontoxic, suggesting potential for bone augmentation.

Approaching 3D printing in oral and maxillofacial surgery - suggestions for structured clinical standards

PURPOSE

With respect to the European Union 2017 amendment of the Medical Device Regulations (MDR), this overview article presents recommendations concerning medical 3D printing in oral and maxillofacial surgery (OMFS).

METHODS

The MDR were screened for applicability of the rules to medical in-house 3D printing. Applicable regulations were summarized and compared to the status of medical use of 3D printing in OMFS in Germany. Recommendations were made for MDR concerning medical 3D printing.

RESULTS

In-house printed models, surgical guides, and implants fall under the category of Class I-III, depending on their invasive and active properties. In-house medical 3D printing for custom-made medical devices is possible under certain prerogatives: (1) the product is not being used in another facility, (2) appropriate quality systems are applied, (3) the reason for omitting commercial products is documented, (4) information about its use is supplied to the responsible authority, (5) there is a publicly accessible declaration of origin, identification, and conformity to the MDR, (6) there are records of manufacturing site, process and performance data, (7) all products are produced according to the requirements proclaimed before, and (8) there is an evaluation of clinical use and correction of possible issues.

CONCLUSION

Several aspects must be addressed for in house medical 3D printing, according to the MDR. Devising MDR related to medical 3D printing is a growing challenge. The implementation of recommendations in OMFS could help practitioners to overcome the challenges and become aware of the in-house production and application of 3D printed devices.

High-Temperature Polylactic Acid Proves Reliable and Safe for Manufacturing 3D-Printed Patient-Specific Instruments in Pediatric Orthopedics-Results from over 80 Personalized Devices Employed in 47 Surgeries

(1) Background: Orthopedic surgery has been transformed by 3D-printed personalized instruments (3DP-PSIs), which enhance precision and reduce complications. Hospitals are adopting in-house 3D printing facilities, using cost-effective methods like Fused Deposition Modeling (FDM) with materials like Polylactic acid (PLA) to create 3DP-PSI. PLA's temperature limitations can be overcome by annealing High-Temperature PLA (ann-HTPLA), enabling steam sterilization without compromising properties. Our study examines the in vivo efficacy of ann-HTPLA 3DP-PSI in pediatric orthopedic surgery. (2) Methods: we investigated safety and efficacy using ann-HTPLA 3DP-PSI produced at an "in-office" 3D-printing Point-of-Care (3DP-PoC) aimed at correcting limb deformities in pediatric patients. Data on 3DP-PSI dimensions and printing parameters were collected, along with usability and complications. (3) Results: Eighty-three ann-HTPLA 3DP-PSIs were utilized in 33 patients (47 bone segments). The smallest guide used measured 3.8 cm3, and the largest measured 58.8 cm3. Seventy-nine PSIs (95.2%; 95% C.I.: 88.1-98.7%) demonstrated effective use without issues. Out of 47 procedures, 11 had complications, including 2 infections (4.3%; 95% CI: 0.5-14.5%). Intraoperative use of 3DP-PSIs did not significantly increase infection rates or other complications. (4) Conclusions: ann-HTPLA has proven satisfactory usability and safety as a suitable material for producing 3DP-PSI in an "in-office" 3DP-PoC.

A survey regarding the organizational aspects and quality systems of in-house 3D printing in oral and maxillofacial surgery in Germany

PURPOSE

The aim of the study was to get a cross-sectional overview of the current status of specific organizational procedures, quality control systems, and standard operating procedures for the use of three-dimensional (3D) printing to assist in-house workflow using additive manufacturing in oral and maxillofacial surgery (OMFS) in Germany.

METHODS

An online questionnaire including dynamic components containing 16-29 questions regarding specific organizational aspects, process workflows, quality controls, documentation, and the respective backgrounds in 3D printing was sent to OMF surgeons in university and non-university hospitals as well as private practices with and without inpatient treatment facilities. Participants were recruited from a former study population regarding 3D printing; all participants owned a 3D printer and were registered with the German Association of Oral and Maxillofacial Surgery.

RESULTS

Sixty-seven participants answered the questionnaires. Of those, 20 participants ran a 3D printer in-unit. Quality assurance measures were performed by 13 participants and underlying processes by 8 participants, respectively. Standard operating procedures regarding computer-aided design and manufacturing, post-processing, use, or storage of printed goods were non-existent in most printing units. Data segmentation as well as computer-aided design and manufacturing were conducted by a medical doctor in most cases (n = 19, n = 18, n = 8, respectively). Most participants (n = 8) stated that "medical device regulations did not have any influence yet, but an adaptation of the processes is planned for the future."

CONCLUSION

The findings demonstrated significant differences in 3D printing management in OMFS, especially concerning process workflows, quality control, and documentation. Considering the ever-increasing regulations for medical devices, there might be a necessity for standardized 3D printing recommendations and regulations in OMFS.

A Review of Polylactic Acid as a Replacement Material for Single-Use Laboratory Components

Every year, the EU emits 13.4 Mt of CO₂ solely from plastic production, with 99% of all plastics being produced from fossil fuel sources, while those that are produced from renewable sources use food products as feedstocks. In 2019, 29 Mt of plastic waste was collected in Europe. It is estimated that 32% was recycled, 43% was incinerated and 25% was sent to landfill. It has been estimated that life-sciences (biology, medicine, etc.) alone create plastic waste of approximately 5.5 Mt/yr, the majority being disposed of by incineration. The vast majority of this plastic waste is made from fossil fuel sources, though there is a growing interest in the possible use of bioplastics as a viable alternative for single-use lab consumables, such as petri dishes, pipette tips, etc. However, to-date only limited bioplastic replacement examples exist. In this review, common polymers used for labware are discussed, along with examining the possibility of replacing these materials with bioplastics, specifically polylactic acid (PLA). The material properties of PLA are described, along with possible functional improvements dure to additives. Finally, the standards and benchmarks needed for assessing bioplastics produced for labware components are reviewed.

How to Sterilize Polylactic Acid Based Medical Devices?

How sterilization techniques accurately affect the properties of biopolymers continues to be an issue of discussion in the field of biomedical engineering, particularly now with the development of 3D-printed devices. One of the most widely used biopolymers in the manufacture of biomedical devices is the polylactic acid (PLA). Despite the large number of studies found in the literature on PLA devices, relatively few papers focus on the effects of sterilization treatments on its properties. It is well documented in the literature that conventional sterilization techniques, such as heat, gamma irradiation and ethylene oxide, can induced damages, alterations or toxic products release, due to the thermal and hydrolytical sensitivity of PLA. The purposes of this paper are, therefore, to review the published data on the most common techniques used to sterilize PLA medical devices and to analyse how they are affecting their physicochemical and biocompatible properties. Emerging and alternative sterilization methods for sensitive biomaterials are also presented.

In-House, Fast FDM Prototyping of a Custom Cutting Guide for a Lower-Risk Pediatric Femoral Osteotomy

Three-dimensional printed custom cutting guides (CCGs) are becoming more and more investigated in medical literature, as a patient-specific approach is often desired and very much needed in today’s surgical practice. Three-dimensional printing applications and computer-aided surgical simulations (CASS) allow for meticulous preoperatory planning and substantial reductions of operating time and risk of human error. However, several limitations seem to slow the large-scale adoption of 3D printed CCGs. CAD designing and 3D printing skills are inevitably needed to develop workflow and address the study; therefore, hospitals are pushed to include third-party collaboration, from highly specialized medical centers to industrial engineering companies, thus increasing the time and cost of labor. The aim of this study was to move towards the feasibility of an in-house, low-cost CCG 3D printing methodology for pediatric orthopedic (PO) surgery. The prototype of a femoral cutting guide was developed for its application at the IOR—Rizzoli Orthopedic Institute of Bologna. The element was printed with an entry-level 3D printer with a high-temperature PLA fiber, whose thermomechanical properties can withstand common steam heat sterilization without bending or losing the original geometry. This methodology allowed for extensive preoperatory planning that would likewise reduce the overall surgery time, whilst reducing the risks related to the intervention.