RESUMO
Background: Polyetheretherketone (PEEK) has favorable properties that make it able to be used as a denture base material, but it is also susceptible to the adhesion of microorganisms. In this study, we applied Octafluoropentyl (meth) acrylate (OFPA) coating on the PEEK polymer surface by using plasma spray and investigated the functional groups present on the surface, changes in the surface energy and Candida albicans adhesion. Materials and Methods: In this experimental study, the samples were placed in a control group without surface preparation and three experimental groups that were subjected to plasma spray for 10, 30, and 60 s and then impregnated with degassed Octa fluoropentyl (meth) acrylate (Sigma-Aldrich, USA) monomer. Fourier transform infrared spectroscopy (FTIR) was used to identify the functional groups and new chemical bonds between PEEK and OFPA, and Sessile Drop Method was used to evaluate the surface's wettability. The surface morphology was checked using a LEXT OLS4000 (Olympus®-Japan) microscope, and the inhibition of C. albicans adhesion was also checked by counting the colonies in terms of colony forming unit/mL (CFU/mL). Kurskal-Wallis analysis was conducted to assess Candida adhesion, while wettability was evaluated using analysis of variance and post hoc analyses. The level of statistical significance was set at P < 0.05. Results: FTIR analysis confirmed that a chemical between OFPA and PEEK was established. The samples showed a significant increase in the contact angle after 30 s of plasma application (CA = 88.2 ± 7.3). The contact angle decreased again by increasing the surface modification to 60 s (CA = 64.33 ± 5.5). Examining the surface morphology of the samples shows an increase in surface roughness with increasing plasma time up to 60 s. The number of adherent colonies was the lowest in 30 s group, but it was not statistically significant (P = 0.658). Conclusion: No statistically significant difference in C. albicans CFU/mL count was found between groups. The contact angle of the 30 s group was significantly higher than the control group.
RESUMO
Background: Cleaning and shaping of root canals are essential steps for the success of endodontic therapy. This study compared two types of rotary files in oval-shaped root canals: XP-endo shaper (FKG, La Chaux-de- Fonds, Switzerland) and Mtwo (VDW, Germany, Munich) with regard to cleaning ability and canal preparation. Mtwo is a system of nickel-titanium files with S-shaped cross-sectional design and XP-endo shaper can change its shape according to the temperature. Materials and Methods: This in vitro study was performed on 16 pairs of freshly extracted contralateral mandibular premolars with a single oval-shaped canal that were selected and divided into two groups according to the root canal instrumentation technique: XP-endo shaper and Mtwo. Then, each root cut into three coronal, middle and apical sections and processed for histologic evaluation of canal wall planning and the presence of debris. Sections were evaluated by using AutoCAD 2017 software. Statistical analysis was used to compare between both the groups using repeated measures multivariate analysis of variance with Bonferroni correction for post hoc comparison and independent sample t-tests. The level of statistical significance was set at P < 0.05. Results: With a statistically significant difference in the middle third, untouched area and area with debris in XP-endo shaper group were smaller (respectively P = 0.013 and P = 0.011). Despite the percentage difference between groups, there was not a statistically significant difference in other sections. Conclusion: Statistically in the middle section of the oval-shaped canals, the XP-endo shaper performs better than the Mtwo rotary files.
