Aims. The aim of this study was to determine prevalence of oral manifestations related to COVID-19 infection among a sample of recovered patients in the Basrah province of Iraq. Methodology. This cross-sectional study included a total of 574 individuals from Basrah city, Iraq (196 males and 378 females), who had been previously infected with COVID-19. A questionnaire was developed and used to record the demographic data, medical history, severity of respiratory infection followed by hospitalization along with oral signs and symptoms that occurred during the COVID-19 infection and their persistence after recovery. Results. Oral manifestations were reported in 88.3% of the studied sample. The most common oral manifestation was ageusia (66.8%), followed by dry mouth (59%), gustatory changes (46%), dysphagia (40.5%), burning sensation (20.8%), oral ulceration (14.5%), and gingival bleeding (3.3%). The findings suggested that ageusia was the only symptom that persisted following recovery from the COVID-19 infection. The results showed a significant statistical correlation between the incidence of oral manifestations and the severity of COVID-19 infection followed by hospitalization. A significant correlation was also found between the age groups and COVID-19 oral manifestations, whereas no significant statistical relationship was observed between gender, smoking, and systemic diseases. Conclusions. COVID-19 infection has considerable impacts on the oral cavity and salivary glands and after recovery from the infection, some patients continue to complain of ageusia for several months. There is a positive correlation between the incidence of oral signs and symptoms associated with COVID-19 infection and the severity of the infection.

Problem: The commonly used acrylic resins for fabricating denture base suffer from poor mechanical properties. Aim: This study aimed to assess the effect of incorporating Titanium Dioxide (TiO2) nanoparticles (NPs) as a reinforcement agent on the compressive strength of different acrylic denture base materials. Materials and methods: Thirty-two cylindrical specimens (22 mm in height and 12 mm in diameter) were prepared from PMMA resins with and without TiO2 NPs. They were allocated into two main groups according to the materials used such as cold cure and heat cure denture base resins and then divided into two subgroups each containing eight specimens: control (without nanoparticles) and experimental (with 2 wt.% TiO2 NPs). TiO2 NPs were synthesized via a chemical processing route. Particle morphology and size distribution were assessed using SEM and AFM while XRD technique was employed to determine the crystalline structure of the NPs. Compression test was performed on the specimens using a universal Instron testing machine to compare the compressive strength. Results: Size of crystalline TiO2 NPs varied between 40-80 nm. The mean compressive strength for the cold cure acrylic resin (control group) and its nanocomposite (experimental group) were found to be 15.37 MPa and 17.42 MPa while for the heat cure acrylic resin and its nanocomposite were 23.04 MPa and 24.30 MPa. A statistically significant difference was recorded between the compressive strengths of cold cure acrylic resin and its nanocomposite. However, the difference was non-significant in the case of heat cure acrylic resin. Conclusion: The compressive strengths of both cold cure and heat cure acrylic resins increased after the incorporation TiO2 NPs.

Peracetic acid (PAA) is widely used as a sterilizing/disinfecting agent, and, in endodontics, it has been introduced as a promising irrigant in root canal treatment. It has been used at different concentrations to achieve various functions. However, endodontic instruments in contact with PAA of a certain concentration may affect their fatigue resistance. Therefore, the aim of this study was to investigate the impact of PAA on the cyclic fatigue resistance of three commercial heat-treated nickel-titanium (NiTi) rotary files. Three types of heat-treated NiTi rotary files were selected: One Curve (OC), ProTaper Gold (PTG), and Wave One Gold (WOG). Each type was divided into three subgroups (n = 6 for each file type): (1) untreated instruments; (2) files immersed in 0.002% PAA; and (3) files immersed in 0.35% PAA. The performance of each file type was tested in a simulated canal. The number of cycles to fracture (NCF) was determined to assess cyclic fatigue resistance of the files. Independent sample t-test was applied to compare each treated file within a subgroup with its respective control group, and one-way ANOVA was used for comparison among the main groups. All types of tested files revealed a significant decline in the cyclic fatigue resistance after exposure to 0.002% PAA except the PTG ( P = 0.209 ). After exposure of the files to a higher concentration (0.35% PAA), a dramatic reduction was demonstrated by all the groups. Before and after exposure of the files to PAA, PTG displayed the highest cyclic fatigue resistance, followed by the WOG, while the OC showed the lowest resistance. Exposure of heated-treated NiTi files to PAA in a relatively high or low concentration adversely affects the cyclic fatigue resistance. The PTG files demonstrated the best performance among the tested types and can be disinfected with 0.002% PAA for clinical purpose.

In this in vitro study, we assessed the antibacterial efficacy of four endodontic sealers-resin AH26, EndoRez, calcium hydroxide (Apexit), and pure zinc oxide-against Enterococcus faecalis. The agar diffusion test was employed to evaluate the antibacterial efficacy of the sealers in vitro, with distilled water serving as a control. The sealers were prepared following the manufacturer's instructions and placed in wells of 50 agar plates, each inoculated with 15 samples of Kocuria rhizophila and Staphylococcus aureus. Inhibition zones were assessed after 72, 120, and 168 hours of anaerobic incubation at 37°C for 196 hours. Kruskal-Wallis and Friedman tests were used for data analysis. Positive control plates exhibited bacterial growth in all specified periods. AH26 demonstrated significantly higher antibacterial effectiveness against both bacterium types compared to the other sealers (P<0.01). Pure zinc oxide exhibited moderate antibacterial activity, while Apexit and EndoRez showed the lowest activity against S. aureus and no activity against K. rhizophila. AH26 had the highest antibacterial effect, and EndoRez had the lowest (P<0.05). In terms of inhibiting bacterial growth, the effectiveness of root canal sealers was ranked as follows: AH26 > Pure Zinc Oxide > Apexit/EndoRez.