Modified Hybrid Hydroxyapatite-Silver Nanoparticles Activated via a Blue Light Source in Various Concentrations in Two-Step Self-Etch Adhesive to Caries-Affected Primary Dentin.

Aims: To evaluate hydroxyapatite-silver (HA-Ag) hybrid nanoparticles (NPs), as an antibacterial agent when integrated in self-etch (SE) adhesive. Blue light activated HA-Ag hybrid NP incorporation on mechanical properties, degree of conversion (DC), and microtensile bond strength (µTBS). Method: Eighty primary molar teeth have carious lesions reaching the dentin but not involving the pulp. The infected dentin was removed and carious-affected dentin (CAD) was preserved. Forty samples were inoculated with Streptococcus mutans. All primary teeth (n = 80) were allocated into four groups based on the incorporation of HA-Ag hybrid NPs in different concentrations (0%, 1%, 5%, and 10%). Group 1: 0% HA-Ag hybrid NPs + Clearfil SE bond primer, group 2: 1% HA-Ag hybrid NPs + Clearfil SE bond primer, group 3: 5 wt% HA-Ag NPs + Clearfil SE bond primer, and group 4: 10 wt% HA-Ag NPs + Clearfil SE bond primer. The survival rate assessment of S. mutans was conducted on 40 inoculated samples. On the remaining primary teeth (n = 40), Clearfil SE bonding agent was applied uniformly via a blue light source. The composite buildup was performed on the samples and µTBS and failure analysis assessed. Fourier transform infrared spectroscopy was performed to assess DC. Survival rates of S. mutans and µTBS among the tested groups were compared using ANOVA and Tukey post hoc analysis. Results: 10 wt % HA-Ag NPs + Clearfil SE bond primer exhibited the highest level of antibacterial efficacy (0.14 ± 0.02 CFU/mL) against S. mutans. The highest µTBS (18.38 ± 0.78 MPa) at the composite/CAD interface was in group 2 (1 wt % HA-Ag NPs + Clearfil SE bond primer + Clearfil SE bonding agent + activation with a blue light source). The highest DC was observed in the control group with Clearfil SE bond primer + Clearfil SE bonding agent + activation with a blue light source. Conclusion: 1 wt% HA-Ag hybrid NPs showed enhanced antibacterial effectiveness, DC, and bond strength of the SE adhesive to the primary CAD.

Dental Students' Perception, Awareness and Knowledge About HPV Infection, Vaccine, and Its Association with Oral Cancer: A Multinational Study.

Background: Human papilloma virus (HPV) infection forms a major etiological factor for oropharyngeal cancer (OPC), which has exhibited increased global incidence. Aim: To compare the knowledge regarding HPV, its association with OPC, and HPV vaccine among students from different countries, years of the undergraduate program, and gender. Methods: The current multinational cross-sectional study was conducted in 886 undergraduate dental students from Egypt, India, Pakistan, Saudi Arabia, UAE, and Sudan through Google survey forms from July 2021 to September 2021. The survey form comprised 27 items divided into four sections. The answers to the questionnaire were compared among students from different countries, different years of the undergraduate program, and males and females. Chi-square test was used to evaluate the correlation between the demographic characteristics of students and their knowledge regarding HPV and OPC. Results: Females exhibited a better knowledge regarding knowledge and perception on HPV vaccine, whereas males exhibited a better knowledge regarding HPV and its correlation with OPC, and these differences were statistically significant (P < 0.05). The third- and fourth-year undergraduate students displayed a higher awareness of OPC and its connection with HPV than other year students, and this variance was found to be statistically significant (P < 0.001). Third-year and internship students exhibited a more positive attitude and comfort regarding the vaccine and discussing the same with patients than the other educational-level students. Students from India exhibited better knowledge about HPV and its association with OPC than the students from other countries, and this difference was statistically significant (P < 0.001). Conclusion: Disparities in knowledge regarding HPV-related oral cancer have been detected among the female and male participants among different nations. From the entire study population, Indian students exhibited better knowledge regarding HPV. Females from all the nations exhibited a more positive attitude and comfort regarding the vaccine and discussing the same with patients than males. The results of this necessitate intervention measures including training workshops and awareness campaigns. Improving their knowledge regarding the same may increase their awareness, resulting in better patient care.