Bacterial Adhesion on Dental Polymers as a Function of Manufacturing Techniques

Abstract

The microbiological behavior of dental polymer materials is crucial to secure the clinical success of dental restorations. Here, the manufacturing process and the machining can play a decisive role. This study investigated the bacterial adhesion on dental polymers as a function of manufacturing techniques (additive/subtractive) and different polishing protocols. Specimens were made from polyaryletherketone (PEEK, PEKK, and AKP), resin-based CAD/CAM materials (composite and PMMA), and printed methacrylate (MA)-based materials. Surface roughness (Rz; Ra) was determined using a laser scanning microscope, and SFE/contact angles were measured using the sessile drop method. After salivary pellicle formation, in vitro biofilm formation was initiated by exposing the specimens to suspensions of Streptococcus mutans (S. mutans) and Streptococcus sanguinis (S. sanguinis). Adherent bacteria were quantified using a fluorometric assay. One-way ANOVA analysis found significant influences (p < 0.001) for the individual parameters (treatment and material) and their combinations for both types of bacteria. Stronger polishing led to significantly (p < 0.001) less adhesion of S. sanguinis (Pearson correlation PC = −0.240) and S. mutans (PC = −0.206). A highly significant (p = 0.010, PC = 0.135) correlation between S. sanguinis adhesion and Rz was identified. Post hoc analysis revealed significant higher bacterial adhesion for vertically printed MA specimens compared to horizontally printed specimens. Furthermore, significant higher adhesion of S. sanguinis on pressed PEEK was revealed comparing to the other manufacturing methods (milling, injection molding, and 3D printing). The milled PAEK samples showed similar bacterial adhesion. In general, the resin-based materials, composites, and PAEKs showed different bacterial adhesion. Fabrication methods were shown to play a critical role; the pressed PEEK showed the highest initial accumulations. Horizontal DLP fabrication reduced bacterial adhesion. Roughness < 10 µm or polishing appear to be essential for reducing bacterial adhesion.

Methods to improve antibacterial properties of PEEK: A review

“…Among commercial PEEK dental products, there were no significant differences between injected molded samples and printed samples of PEEK in adhesion of S. sanguinis. In contrast, pressed PEEK samples showed significantly higher adhesion [33]. On the other hand, another bacteria, S. mutans, had no differences in adhesion based on the manufacturing technique [33].…”

“…In contrast, pressed PEEK samples showed significantly higher adhesion [33]. On the other hand, another bacteria, S. mutans, had no differences in adhesion based on the manufacturing technique [33].…”

Green Method for the Preparation of Durable Superhydrophobic Antimicrobial Polyester Fabrics with Micro-Pleated Structures

“…A biofilm is a community of microorganisms characterized by bacterial cells that are irreversibly attached to a substratum or interface, or to each other, embedded in a matrix of extracellular polymeric substances that they have produced [ 10 , 11 ]. Researchers have observed that biofilm formation follows a sequential colonization, from early colonizers such as streptococci, to bacterial proliferation, and to the final formation of biofilm [ 12 ], in which surface properties, such as morphology, chemistry, and surface energy, are the main factors affecting interfacial interactions [ 13 , 14 ]. According to the Cassie–Baxter wettability model, superhydrophobic surfaces (characterized by a water contact angle (WCA) of ≥ 150° and sliding angle SA of ≤ 10°) exhibit non-wetting, anti-fouling, and self-cleaning properties, resulting from the combination of low surface energy and surface roughness [ 15 , 16 ].…”

Denture Stomatitis and Candida albicans in the Indian Population: A Systematic Review and Meta-Analysis

“…Ill-fitting dentures can exert pressure on the soft tissues of the mouth, leading to friction and sore spots [7]. This continuous irritation creates an environment where fungal infections, notably C. albicans, can thrive, contributing to the development of DS [8][9][10][11]. Conversely, properly fitting and wellmaintained dentures can help prevent denture stomatitis.…”