# 3D Printed Antibacterial Prostheses
## 4 Discussion  
The main findings of the current investigation were that the antibacterial 3D printed filament, PLACTIVETM, can be effectively used for the development of functional 3D printed finger prostheses. Furthermore, the antibacterial properties of the 3D printing filament after extrusion were not affected (Table 1). The thermoforming properties of polylactic acid were not affected by the addition of copper nanoparticles and allowed for necessary post-processing modifications for the final fitting of the 3D printed antibacterial finger prosthesis. Previous investigations have described the use of silver compounds to develop antibacterial lower limbs [24] and dental prostheses [25]. A recent review [24] identified silver as being the main compound used to reduce sweat and odor build-up at the socket interface. Similarly, [PERSON] et al. [25] described the use of silver compounds for dental prostheses with the objective of reducing bacterial adhesion to dental materials and thus, reducing the incidence of caries and periodontitis [25]. However, there is some evidence that the use of silver compounds may result in local skin irritation and discoloration [13]. Furthermore, copper compounds have been described as a low-cost alternative to silver, with high potential for the development of medical devices with powerful antibacterial properties [11; 12]. The addition of nanoparticles of copper to polymers and the resulting antimicrobial properties have promising applications in the development of transitional prostheses [12]. The term \"post-operative or preparatory prosthesis\" has been widely used in the field of prosthetics [10; 26]. More recently, these types of devices have been referred as \"temporary prostheses,\" \"initial prostheses,\" or \"transitional prostheses\" [9]. Previous investigations have used transitional prosthetic devices with \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Laboratory** & **Inoculum (Initial Load, *CFU/mL)** & **Log10 Reduction at 24 h** & **Reduction (\%)** \\ \hline \multirow{3}{*}{**1**} & Methicillin-resistant _Staphylococcus aureus_ & & \\  & (7.10E+9) & & \\ \cline{2-4}  & _Escherichia coli_ (3.33E+9) & 1.32 & 95.03 \\ \hline \multirow{3}{*}{**2**} & _Staphylococcus aureus_ (6.3E+5) & 5.7 & 99.99 \\ \cline{2-4}  & _Escherichia coli_ (9.3E+5) & 4.6 & 99.99 \\ \hline \hline \end{tabular}  
* CFU: colony forming unit.  
\end{table} 
Table 1: Bacterial analysis summary. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Items** & **Subject 1** & **Subject 2** \\ \cline{2-3}
**How Satisfied Are You with *:** & & \\ \hline Dimensions (size, height, length, width) & 5.0 & 4.2 \\ Weight & 4.7 & 4.7 \\ Adjustments (fixing, fastening) & 4.3 & 4.3 \\ Safety (secure) & 5.0 & 5.0 \\ Durability (endurance, resistance to wear) & 4.5 & 4.5 \\  & Ease of use & 5.0 & 4.5 \\  & Comfort & 5.0 & 5.0 \\ Effectiveness (the degree to which your device meets your needs) & 4.6 & 4.5 \\  & Device satisfaction & 4.76 \(\pm\) 0.28 & 4.59 \(\pm\) 0.29 \\ \hline
**Box and Block Test (Blocks per Minute)** & & \\ Without prosthesis (3 trials) & 17.7 \(\pm\) 0.6 & 21.0 \(\pm\) 1.0 \\ With prosthesis (3 trials) & 22.3 \(\pm\) 1.5 & 32.3 \(\pm\) 2.5 \\ \hline \hline \end{tabular}  
* 1 = not satisfied at all, 2 = not very satisfied, 3 = more or less satisfied, 4 = quite satisfied, 5 = very satisfied.  
\end{table} 
Table 2: Quebec User Evaluation of Satisfaction with assistive Technology (QUEST) Ratings and Box and Block Test. the objective of restoring and preserving strength and range of motion in children with upper-limb reduction deficiencies [8; 27]. A transitional prosthesis can be used while the patient's residual limb is still healing to decrease edema and allow the patient to improve wear tolerance. A recently amputated limb, however, is particularly susceptible to infections and skin disorders [10]. The current findings suggest that the 3D printing antibacterial filament may also be used to manufacture more effective and sanitary transitional prostheses.