An In Situ Evaluation of the Protective Effect of Nano Eggshell/Titanium Dioxide against Erosive Acids

Evaluation of Nano TiO2 Modified Orthodontic Composite Effects on S. mutans Population and Enamel Demineralization in Fixed Orthodontic Patients; a Split Mouth Randomized Controlled Clinical Trial

The high incidence of demineralization around orthodontic brackets has led to the development of preventive measures. Incorporation of antibacterial or remineralizing agents into orthodontic adhesives is an attractive method. This single-center, split-mouth, randomized controlled clinical trial was conducted to assess the effect of a modified composite containing TiO2 nanoparticles on the Streptococcus mutans population and to prevent demineralization around orthodontic brackets. Each participant was assigned a random sequence (AB or BA). During the bonding session, the control lateral incisor was bonded with a conventional composite and the contralateral incisor was bonded with a composite containing nano TiO2 particles (1%weight). The eligibility criteria included the presence of S. mutans in the dental plaque and absence of active caries, fractures or cracks. The S. mutans count in the dental plaque immediately around the brackets was evaluated at baseline and 1, 3, and 6 months after bonding. The specificity of the colonies was determined by PCR. The DIAGNOdent score was assessed at baseline and re-assessed every month up to the sixth month. Salivary samples were collected at T0, T1, and T3 to assess the amount of Ti released from the composite. The cytotoxicity of the modified composites was evaluated using an MTT assay. Participants, examiners, and data analyzers were blinded to the test and intervention groups. Forty-two patients ranging from 12 to 25 years were enrolled in this study. The amount of Ti released into saliva was insignificant and far below the toxic level. There was no significant difference between the S. mutans counts of the studied tooth S. mutans counts at any time point evaluated. DIAGNOdent scores on both sides increased significantly after the first month. However, this increase was higher on the test side (p < 0.001), and a significant difference of 2.6 scores remained throughout the study period. No severe adverse events were observed. Orthodontic composites containing TiO2 nanoparticles may prevent demineralization induced around brackets during orthodontic treatment. However, the antibacterial effects were not statistically significant.Registration: The protocol was registered with the IRCT.ir (IRCT20140215016582N6).

Eggshell as a biomaterial can have a sorption capability on its surface: A spectroscopic research

In this study, eggshell as a biomaterial was used as an adsorbent. This natural waste material is easy to access and cost-free. The surface of the eggshell with its porous structure showed affinity to adsorb damaging chemicals. In particular insecticides cause serious environmental pollution in agriculture, and this is a general problem all over the world. The aim was to remove insecticides from the environment and monitor the pesticides on the surface of eggshells by atomic force microscopy (AFM) images, Fourier transform infrared (FTIR) and UV/Vis spectroscopic techniques. Five types of eggshells, Denizli Hen, Coturnix Coturnix Japonica, Light Brahma Chicken, Alectoris Chukar and ISA Tinted -White, were used. Since they are commonly used, Cypermethrin, Deltamethrin and Indoxacarb were chosen as insecticide samples. The interaction effect of insecticides on the surface of eggshells was determined by AFM images; it was seen that the semispherical surface structures of the eggshells were flattened after adsorption. FTIR spectroscopy was used both to detect structural analysis and to determine the adsorption influence. In addition, UV-Vis spectroscopy was performed to evaluate the adsorption and desorption process. Porous media of different types of eggshells with an aqueous solution of insecticides had an electronegativity attractive surface which makes it an ideal adsorbent via hydroxyl groups.

Evaluating the Abrasivity of a Nanosized Eggshell-Titanium Dioxide on Tooth Enamel Using Atomic Force Microscopy

Objectives  This study aimed to evaluate nanosized eggshell–titanium dioxide (EB@TiO ² ) abrasiveness in comparison with calcium carbonate and hydrated silica-containing toothpaste.

Material and Methods  Thirty-five bovine tooth enamels were prepared, and specimens randomly assigned to a sample group of five ( n = 7), namely, Colgate regular, Colgate pro-relief, Sensodyne rapid relief, Sensodyne repair, and EB@TiO ₂ . Half of the enamel surface was brushed with each respective sample group, while the other half was covered with a tap.

Statistical Analysis  The mean roughness value (Ra) of the brushed and covered halves were measured using an atomic force microscope (AFM). To assess the surface morphology and changes, a scanning electron microscope (SEM) was performed. Using pair sample test and ANOVA, the Ra for the entire specimens were analyzed. A Bonferroni correction was used to identify the mean differences among the five groups (α=.05).

Results  The findings from this analysis show that all the tested toothpaste abraded the enamel significantly ( p < 0.05). The abrasive value contained in toothpaste comprising calcium carbonate was lower than the silica toothpaste hydrated.

Conclusion  Overall, Colgate regular had the lowest toothpaste abrasivity, followed by EB@TiO2, while Sensodyne rapid relief had the most enamel wear. The prominent feature of this study suggests that EB@TiO2 is suitable for oral use, as its abrasivity is comparable with calcium carbonate-containing toothpaste.

Evaluation of the Occluding Characteristics of Nanosized Eggshell/Titanium Dioxide with or without Saliva

OBJECTIVES

 The study reports on the effectiveness of a ball-milled nanosized titanium dioxide composite (EB@TiO₂) for DH management in comparison with commercial desensitizing paste with and without saliva.

MATERIALS AND METHODS

  Forty-nine dentine specimens were prepared from extracted bovine anterior teeth. Twenty-one of the specimens were brushed with three desensitizing toothpaste for 7 days, namely: Group 1; EB@TiO₂, Group 2; Colgate Pro-relief; and Group 3; Sensodyne repair (n = 7). Twenty-four specimens were brushed with the toothpaste for 7 days and stored in artificial saliva (control) after brushing. Each specimen was subsequently posttreated in citric acid solution to test its stability in acidic condition. Field scanning electron microscope was used to evaluate the effectiveness of the dentine tubules occlusion. The biocompatibility of the composite was tested using BHK21 cell line.

STATISTICAL ANALYSIS

 One-way analysis of variance was used to analyze the percentage occluded area ratio values for all specimens (α = 0.05). Independent t-test was further used to evaluate the occlusion differences with saliva and without saliva.

RESULTS AND CONCLUSIONS

 The number of dentine tubules decreased significantly after 7 days of brushing. Overall, the occlusion observe for EB@TiO₂ were significantly better than for Colgate Pro-relief and Sensodyne repair (p < 0.05). BHK21 assay suggested that composite had no significant effect on the BHK21 cell line. This study demonstrated that the composite effectively occluded open dentine tubules within 7 days of brushing.

Corrigendum to "An In Situ Evaluation of the Protective Effect of Nano Eggshell/Titanium Dioxide against Erosive Acids"

[This corrects the article DOI: 10.1155/2018/4216415.].