Neusa Silva

This study investigated fibroblast and bacteria proliferation on polyetheretherketone (PEEK)‐implant material 3D‐printed by fused deposition modeling (FDM) in comparison to titanium (cp‐Ti) and zirconia (ZrO ₂ ). Four groups were tested, including horizontally FDM‐printed PEEK (PH), vertically printed FDM‐PEEK (printed vertically [PV]), cp‐Ti and ZrO ₂ . Human gingival fibroblasts were cultured on discs (15/group), with viability evaluated at 1‐, 3‐, and 7‐d and cytokine production (IL‐6 and IL‐8) measured at 3‐d. Discs (9/group) were exposed to Streptococcus oralis with bacteria counted at 1‐ and 2‐d. Discs underwent scanning electron microscopy and surface roughness testing. Although fibroblast proliferation was similar for all groups at 24 h, values were significantly higher for PV than ZrO ₂ at 3‐d. At 7‐d, fibroblast proliferation was significantly lower on PH than cp‐Ti. Bacterial adhesion for ZrO ₂ was lower than other groups at 24 h and lower than PV and PH at 48 h. IL‐8 production was similar between groups, whereas IL‐6 was higher on cp‐Ti compared to ZrO ₂ . PV was significantly rougher than other groups. FDM‐PEEK induces early fibroblast adhesion and viability and bacterial colonization comparable to reference implant materials. The positive outcomes of this study underscore FDM‐PEEK as a promising biomaterial comparable to established implant and prosthetic materials in terms of favorable biological responses and potential soft‐tissue seal.

This study aimed to evaluate zirconia dental implant surfaces patterned using Nd:YAG laser or conventional milling techniques against Streptococcus oralis adhesion and biofilm formation. Zirconia dental implant discs were subjected to surface patterning treatments and categorized into four groups: groove texturing by conventional milling (GM), pore texturing by conventional milling (PM), groove texturing by Nd:YAG laser (GL), and pore texturing by Nd: YAG laser (PL). Streptococcus oralis CECT 907T was cultivated on enriched blood agar plates and then transferred to a brain–heart infusion modified medium and incubated at 37 °C under anaerobic conditions until reaching the exponential growth phase. The bacterial suspension was then seeded on 24-well plates containing the treated discs. The viability of bacteria within the biofilm was determined based on colony-forming unit (CFU) counts, while the total biofilm was quantified by measuring its biomass. A qualitative analysis was conducted using scanning electron microscopy (SEM) images to evaluate the bacterial morphology. The statistical analysis of multigroup comparisons was performed using Kruskal–Wallis test with post hoc pairwise comparison, as well as Mann Whiney U test, with significance set at p < 0.05. After both 1 h and 24 h of incubation of Streptococcus oralis on the discs, all groups showed similar results, with no statistically significant differences (p > 0.05). A comparison of the Nd: YAG laser-treated surfaces with conventionally milled surfaces, as well as grooves versus pores for CFU counts, also revealed no statistically significant differences (p > 0.05) for both 1 h and 24 h of culture. Biomass quantification at both the 1 h and 24-h time points showed similar results across the groups, without statistical differences. When comparing the conventionally machined surfaces to Nd: YAG laser-treated surfaces in terms of biomass, no significant differences were observed (p > 0.05). Similarly, the comparison between groove-patterned surfaces and pore-patterned surfaces showed no statistically significant difference. The groove and pore patterns on zirconia surfaces with Nd: YAG laser or conventional milling did not change the Streptococcus oralis adhesion and biofilm formation behavior. Additional studies are recommended to expand our knowledge in this area.

Soft tissue regeneration plays a crucial role after oral surgery, as the successful healing of the soft tissue is a primary indicator of an efficacious intervention. Cold atmospheric plasma (CAP) has recently emerged as a promising therapeutic modality, exhibiting notable effects on cell migration and proliferation. Despite its potential, the dental application of CAP remains underexplored. This in vitro study aims to elucidate the impact of CAP activated medium on human gingival fibroblast responses, for future wound healing strategies. The study was divided into four parts: initial characterization of the plasma Jet, assessment of cell concentration, exploration of treatment distance effects, and treatment time dynamics. Human gingival fibroblasts were exposed to complete DMEM medium (without sodium pyruvate) activated with CAP at treatment distances of 2, 5, 7, and 9 mm, and treatment times of 15, 60, 120, 180, and 300 s for 1, 2 and 3 d of culture. The cell viability was evaluated using resazurin-based method, while wound healing dynamics was assessed via the scratch assay technique using phase-contrast microscopy. The cell morphology was characterised through fluorescence microscopy using propidium iodide and phalloidin staining, complemented by scanning electron microscopy. The results revealed that treatment distances and exposure times can influence the cell behaviour depending on the cell concentration. For the selected concentration of 1 × 10⁴ cells ml⁻¹, a treatment distance of 9 mm appeared to enhance human gingival fibroblast viability compared to a treatment distance of 2 mm and the control group. The images revealed adherent cells with a pattern typical of fibroblasts. However, no differences were observed for exposure times of 15 s and 180 s. The observed results further evidence that the exposure of the medium to the CAP device promoted an increase in cell viability, proliferation, and attachment in human gingival fibroblasts.

Peri-implantitis continues to be one of the major reasons for implant failure. We propose a new approach to the incorporation of MTA into zirconia implant surfaces with Nd:YAG laser and investigate the biological and the microbiological responses of peri-implant cells. Discs of zirconia stabilized with yttria and titanium were produced according to the following four study groups: Nd:YAG laser-textured zirconia coated with MTA (Zr MTA), Nd:YAG laser-textured zirconia (Zr textured), polished zirconia discs, and polished titanium discs (Zr and Ti). Surface roughness was evaluated by contact profilometry. Human osteoblasts (hFOB), gingival fibroblasts (HGF hTERT) and S. oralis were cultured on discs. Cell adhesion and morphology, cell differentiation markers and bacterial growth were evaluated. Zr textured roughness was significantly higher than all other groups. SEM images reveal cellular adhesion at 1 day in all samples in both cell lines. Osteoblasts viability was lower in the Zr MTA group, unlike fibroblasts viability, which was shown to be higher in the Zr MTA group compared with the Zr textured group at 3 and 7 days. Osteocalcin and IL-8 secretion by osteoblasts were higher in Zr MTA. The Zr textured group showed higher IL-8 values released by fibroblasts. No differences in S. oralis CFUs were observed between groups. The present study suggests that zirconia implant surfaces coated with MTA induced fibroblast proliferation and osteoblast differentiation; however, they did not present antibacterial properties.

Peri-implantitis continues to be one of the major reasons for implant failures. We propose a new approach for incorporating MTA into Zirconia implant surfaces with Nd:YAG laser and investigate the biological response of peri-implant cells as well as the microbiological response. Discs of Zirconia stabilized with Yttria and Titanium were produced according 4 tested groups: Nd:YAG laser textured Zirconia coated with MTA (Zr MTA); Nd:YAG laser textured Zirconia (Zr Textured); Zirconia and Titanium discs (Zr and Ti ). Contact profilometry was used to evaluate surface roughness. Human osteoblasts, gingival fibroblasts and S. oralis were cultured on samples. Cell adhesion and morphology, cell viability, cell differentiation markers and bacterial growth were assessed. Zr Textured roughness was significantly higher compared to all other groups. Cellular adhesion was observed at 1 day in all samples in both cell lines. Osteoblasts viability was lower in Zr MTA group, unlike fibroblasts viability was shown to be higher in Zr MTA group compared to Zr Textured group at 3 and 7 days. Osteocalcin and IL-8 release by osteoblasts were higher in Zr MTA. Zr Textured showed higher IL-8 values released by fibroblasts. No differences in S. oralis CFUs were observed between groups. The results suggest that Zirconia implant surfaces coated with MTA seems to promote fibroblasts proliferation and osteoblasts differentiation, however does not appear to have antibacterial properties.

Hyaluronic acid’s water absorption and expansion capacities define a filler’s ability to lift the tissues. Therefore, studying these properties is essential to better understand filler’s clinical performance. The aim of this study was to evaluate and compare water absorption and expansion (bidimensional and three-dimensional) of five Fillmed fillers (Universal, Fine Lines, Volume, Lips and Lips Soft). Water absorption was measured through swelling ratio 24 hours post-hydration. For two-dimensional expansion, samples were analysed quantitatively and qualitatively, using calibrated photographs, before and two hours after hydration. Three-dimensional volume was evaluated before and immediately after injecting the fillers, and 30 minutes, 2 hours and 24 hours post-injection in ex vivo pig skin. The tissue was scanned with the 3Shape TRIOS scanner and resulting STL files were compared. Group comparisons were analyzed with the one-way ANOVA test, and a p-value ≤ 0,05 was established. Lips showed a statistically higher swelling ratio than other fillers (p < 0,05). Fine Lines had the lowest swelling ratio, even if only statistically significant when compared to Universal (p = 0,021). Fine Lines had a significantly higher initial bidimensional width than all fillers (p < 0,05) except Lips Soft. 24 hours post-injection, Fine Lines had the highest three-dimensional volume, which was statistically higher than Volume’s (p = 0,049). All fillers absorbed water and expanded, with Fine Lines tending to have the highest three-dimensional expansion, despite its lowest viscosity and water absorption. Further studies with larger sample sizes are needed to investigate the influence of other properties over water absorption and expansion.

Barium titanate (BaTiO₃) piezoelectric ceramic may be a potential alternative for promoting osseointegration due to its piezoelectric properties similar to bone electric potentials generated in loading function. In this sense, the aim of this in vitro study was to evaluate the cellular response of human osteoblasts and gingival fibroblasts as well as the impact on S. oralis when in contact with BaTiO₃ functionalized zirconia implant surfaces with piezoelectric properties. Zirconia discs with BaTiO₃ were produced and contact poling (piezo activation) was performed. Osteoblasts (hFOB 1.19), fibroblasts (HGF hTERT) and S. oralis were culture on discs. Cell viability and morphology, cell differentiation markers, bacterial adhesion and growth were evaluated. The present study suggests that zirconia composite surfaces with the addition of piezoelectric BaTiO₃ are not cytotoxic to peri-implant cells. Also, they seem to promote a faster initial osteoblast differentiation. Moreover, these surfaces may inhibit the growth of S. oralis by acting as a bacteriostatic agent over time. Although the piezoelectric properties do not affect the cellular inflammatory profile, they appear to enable the initial adhesion of bacteria, however this is not significant over the entire testing period. Furthermore, the addition of non-poled BaTiO₃ to zirconia may have a potential reduction effect on IL-6 mediated-inflammatory activity in fibroblasts.

Cold atmospheric plasma (CAP), as a noninvasive technology, has shown promise in dentistry as it might successfully treat various oral conditions. The antimicrobial capacity of CAP has been proven and it is effective in reducing the main microorganisms responsible for oral infections. Furthermore, CAP has also been explored in the field of tissue regeneration with a great response from both soft and hard tissue. The surface modification ability of CAP is another area of interest, revealing a potential improvement in the osseointegration of dental implants. Additionally, there are other areas within dentistry that have studied the use of CAP, such as surface disinfection, bleaching, and cavity preparation.