Osteoblastic Cell Responses of Copper Nanoparticle Coatings on Ti-6Al-7Nb Alloy Using Electrophoretic Deposition Method.

Aim: To investigate and compare the cell cytotoxicity, proliferation, cell attachment, and morphology of human fetal osteoblasts (hFOB) cells of coated samples (titanium nanocopper (Ti Cu), titanium nanohydroxyapatite (Ti HA) and titanium nanocopper ion doped hydroxyapatite (Ti Cu/HA) and uncoated samples (Ti) in order to assess the suitability of these surface modifications on Ti-6Al-7Nb for dental implant application. Materials and Methods: The cytotoxicity was studied by examining the hFOB cell response by MTT assessment. The cell morphology was evaluated by inverted microscopy and observed under scanning electronic microscopy (SEM). Results: MTT assay results displayed that the Cu content on the surface of Ti-6Al-7Nb alloys did not produce any cytotoxic effect on cell viability. The cell viability rate in all samples ranges from 97% to 126%, indicating that hFOB cells grew at a high proliferation rate. However, no significant differences in cell viability were observed between Ti and Ti Cu and between Ti HA and Ti Cu/HA groups. Microscopic examination demonstrated no difference in the cell morphology of hFOB among all samples. In addition, SEM observation indicated favorable adhesion and spreading of the cells on the coated and uncoated samples. Conclusions: The surface modification of Ti-6Al-7Nb alloy with Cu, HA, and Cu/HA exhibits good cell biocompatibility, and the Cu has no influence on the cell proliferation and differentiation of hFOB.

Evaluation of Corrosion Behavior by Measuring Passivation Current Density of Dental Implant Coated with Bioceramic Materials.

BACKGROUND: This paper reports the corrosion behavior of uncoated commercially pure titanium and Ti-6Al-4V samples and these coated with hydroxyapatite, partial stabilized zirconia (PSZ), and the mixture of partial stabilized zirconia and hydroxyl-apatite by measuring passivation current density and see if there are any differences between them using electrochemical polarization tests in 37°C Hank's solution. MATERIALS AND METHODS: The electrophoretic deposition method (EPD) was elected to keep the coating materials which are HA, PSZ, and the mixture of 50% HA and 50% PSZ on Cp Ti and Ti-6Al-4V alloy samples. The electrochemical corrosion test was achieved by exposing the coated and uncoated samples to Hank's solution which prepared in the laboratory and measuring the polarization potential, passivation current density, and the open circuit potential for all samples. RESULTS: The results indicated that the passivation current density for all Cp Ti and Ti-6Al-4V alloy groups that coated with HA, PSZ, and with mixture of 50/50 HA and PSZ was less than uncoated groups. There are no significant differences between all Cp Ti groups when compared with all Ti-6Al-4 V alloy groups. The open circuit potential (OCP) for both Cp Ti and Ti -6Al -4V samples was in the following sequence PSZ > HA > mixture of HA and PSZ > uncoated. CONCLUSIONS: Coating significantly decreased the passivation current density of Cp Ti and Ti-6Al-4V alloy.

Clinical Evaluation of Pit and Fissure Sealants Placed by Undergraduate Dental Students in 5-15 Years-old Children in Iraq

Abstract Objective: To clinically evaluate the retention and marginal discoloration of pit and fissure sealants applied to primary and permanent teeth. Material and Methods: The study population encompassed of 5-15 years-old children. After consenting, a light-curing sealant was applied to etched pits and fissures of occlusal surfaces of selected sound teeth. The retention rate and marginal discoloration were assessed, 3 months after application of the sealants based on the criteria proposed by Simonsen's criteria (total retention: score 0, partial loss: score 1, and total loss: score 2). Each tooth was considered as an independent sample during analysis. Results: The achieved sample size was 43 children aged 5-15 years (mean age=10.0 years). Therefore, data of 100 teeth from 43 children were used for the final analysis. The percentage of completely retained sealants (59%) was higher than the percentage of partially retained sealants (23%) and completely missing sealants (18%) after 3 months follow up. Out of 100 sealed teeth, 60% were either had marginal discoloration or completely missing. Using the Mann-Whitney test, there was a statistically significant difference (p<0.05) between primary and permanent teeth in terms of retention. However, there was no statistical difference (p>0.05) between upper and lower teeth in terms of retention. Conclusion: The success rate of fissure sealants after 3 months follow-up was satisfactory.