Objectives: To assess the capability of different orthodontic arch-wires to retain oral biofilm and to correlate the adhesion to surface roughness of the wires. Methods: Four types of orthodontic arch-wires were used for the study, Nickel-titanium (NiTi), Copper nickel-titanium (Cu-NiTi) , Beta Titanium (TMA) & Beta III Titanium (CNA) new arch wires and 4 weeks after intraoral usage, were examined for Surface roughness (SR) using an atomic force microscope (AFM). Adhesion of Streptococcus mutans (MS), Staphylococcus aureus (SA), and Candida albicans (CA) were performed using colony count method. Statistically, the following tests were done: analysis of variance, Pearson correlation coefficient test, post hoc Tukey test. Results: The four wire types showed significant increases in SR (P< 0.05) after 4 weeks of intra-oral usage, TMA wires recorded the highest roughness values while the lowest ones were for NiTi wires. Bacterial adhesion was detected on all wires, ANOVA showed significant differences between the wires concerning MS, SA and CA adhesion. A significant positive correlation (P=.001) was observed between bacterial adhesion and surface roughness after intra-oral exposure. Conclusions: SR of the wires increased after intra-oral use and there was a positive correlation with the biofilm adhesion.

To evaluate a fixed-space maintainer made of light-cure acrylic resin (LCAR) for its flexural and shear bond strength using different bonding systems to the enamel. 45 extracted primary teeth were selected. They were randomly divided into three equal groups (n = 15) along with the type of adhesive system (Tetric Flow, Transbond XT, and Fuji Ortho LC) used for bonding (LCAR) to the tooth surface. Surfaces were treated; LCAR was attached to the treated surfaces using a split Teflon mold. For flexural strength testing, ten bars of LCAR were made using another Teflon-split mold. Shear bond strength and mean flexural strength values were evaluated by a universal testing machine. The highest values of bond strength were recorded for Transbond XT, followed by Tetric Flow, while the lowest values were for Fuji Ortho LC. Various groups had a significant difference as investigated by ANOVA. ARI scores showed no significant difference in debond sites. Mean value and standard deviation of flexural strength for LCAR were 82.83  ± 5.2. LCAR has superior mechanical properties and could be an alternative to currently-in-use space maintainer though in vivo and in vitro trials are needed to progress the ultimate design of LCAR.

Purpose: This study was conducted to evaluate the effect of different staining solutions on color stability and surface roughness (SR) of Nano hybrid composite and acrylic denture teeth. Materials and Methods: Fifty specimens divided into two main groups. Each group divided into 5 subgroups each of 5 specimens of acrylic and composite teeth were used in this test. Teeth were immersed in four coloring solutions in addition to distilled water. Color measurements were performed using spectrophotometer. Color change values were determined before and after immersion in the coloring solutions. The CIE L*a*b* color space was used to evaluate color differences. SR values were evaluated before and following the immersion in coloring solutions using a digital microscope. Results: Showed significant color changes of both types of artificial teeth materials upon immersion in tea, coffee, cola, licorice or distilled water. This color change was greater in case of tea and coffee solutions. The least color change values were obtained from specimens immersed in distilled water. SR values were increased for acrylic teeth compared with composite teeth and there were significant statistical differences in surface roughness of all tested materials after immersion in any of the tested solutions. Conclusions: The acrylic denture teeth material is much more subjected to discoloration than the composite denture teeth material. Surface roughness of all tested teeth of both types recorded statistically significant decrease by immersion in staining solutions.

Objectives: To evaluate the in vivo effect of Titanium dioxide (TiO2) nanoparticles and methacryloyloxyethyl phosphoryl choline (MPC) polymer modifications of glass-ionomer cement, to inhibit demineralization around orthodontic bands. Materials and Methods: 60 orthodontic patients with non-carious molars scheduled for banding were randomly divided into three groups. Grouping was based on (3% MPC, 3% nano-Titanium, and 3%+3% of both by weight) added to the luting glass-ionomer cement (GIC) Medicem, which was used for cementation of prefabricated micro-etched orthodontic bands. Demineralization was recorded by using DiagnoDent pen (KaVo, Biberach, Germany) device. Statistical evaluation was performed with one way ANOA test. Results: Bands cemented with conventional GIC showed the highest bacterial scores in comparison to those cemented with MPC polymer and nano-titanium modified GICs. There was significant difference between teeth banded with 3% MPC, 3% nano-titanium, and 3% MPC + 3% nano-titanium modified GICs. Conclusions: Modification of the banding GIC with MPC polymer and nano-titanium revealed a positive effect on reducing white spots around orthodontic bands.

Objectives: To perform a comparison between ACTIVA BioACTIVE restorative, Nano-filled dental composite and RMGIC for compressive and flexural strength. Materials and methods: A total of 60 specimens were made of (ACTIVA Bioactive-, Filtek Z350XT and Ketac Nano-100 RMGI), thirty specimens were prepared for compressive strength testing and the other 30 specimens were prepared for flexural strength testing using two split Teflon molds with different dimensions. All specimens were kept in distilled water for 24 h, then they were tested by universal testing machine. Results: The Filtek Z350XT recorded the highest values for compressive and flexural strength, while the lowest values were for Ketac Nano-100. There was no statistically significant difference between compressive strength values of Filtek Z350XT and ACTIVA. While there were significant difference among flexural strength values for all the materials. Conclusion: ACTIVA demonstrates mechanical properties comparable to dental composite and superior to traditional RMGIC.