scholarly journals Quantification of Titanium Release From Titanium Dioxide Impregnated Composites in Orthodontic Bonding—An In Vitro Study

2022 ◽  
pp. 030157422110562
Author(s):  
Santosh Rahul Tavva ◽  
Suresh Gorantla ◽  
Vizia Muddada ◽  
Tivanani V D Mahendra ◽  
Ramoji Rao Lenka ◽  
...  

Objective To evaluate the quantity of titanium dioxide nanoparticles released into the artificial salivary medium from orthodontic composite impregnated with 1% weight/weight (w/w) and 5% w/w titanium dioxide nanoparticles (TiO2 NPs) used for bonding metal brackets, thereby eventually comprehending the permissible levels. Materials and Method Eighty freshly extracted teeth for orthodontic treatment were divided into 2 groups of 40 teeth each and were bonded with brackets containing 1% w/w and 5% w/w composite containing titanium dioxide nanoparticles and placed in an artificial salivary medium. Quantification of 1% w/w and 5% w/w composite containing titanium nanoparticles was done using inductively coupled plasma mass spectroscopy for 4 timely periods 24 h, 2 months, 4 months, and 6 months. Results In the teeth that received 1% TiO2, the amount of titanium released was greatest in 2 months with no significant release at later intervals. In the second group that received 5%, there was a significant release of titanium at all intervals, with highest release at second month. On comparing the 2 concentrations at 4 different time intervals, the quantities were significantly greater in the 5% group at all time frames, thus implying a significant increase in titanium released with an increase in concentration from 1% to 5%. Conclusion Titanium release was higher in 5% w/w composite containing nanoparticles than 1% w/w composite containing nanoparticles, and 1% and 5% concentrations can be used safely and are within the permissible limits.

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 724-730 ◽  
Author(s):  
Qing Ge ◽  
Paul A. Cobine ◽  
Leonardo De La Fuente

Xylella fastidiosa is a xylem-limited plant pathogenic bacterium that causes disease in many crops worldwide. Copper (Cu) is an antimicrobial agent widely used on X. fastidiosa hosts to control other diseases. Although the effects of Cu for control of foliar pathogens are well known, it is less studied on xylem-colonizing pathogens. Previous results from our group showed that low concentrations of CuSO4 increased biofilm formation, whereas high concentrations inhibited biofilm formation and growth in vitro. In this study, we conducted in planta experiments to determine the influence of Cu in X. fastidiosa infection using tobacco as a model. X. fastidiosa-infected and noninfected plants were watered with tap water or with water supplemented with 4 mM or 8 mM of CuSO4. Symptom progression was assessed, and sap and leaf ionome analysis was performed by inductively coupled plasma with optical emission spectroscopy. Cu uptake was confirmed by increased concentrations of Cu in the sap of plants treated with CuSO4-amended water. Leaf scorch symptoms in Cu-supplemented plants showed a trend toward more severe at later time points. Quantification of total and viable X. fastidiosa in planta indicated that CuSO4-amended treatments did not inhibit but slightly increased the growth of X. fastidiosa. Cu in sap was in the range of concentrations that promote X. fastidiosa biofilm formation according to our previous in vitro study. Based on these results, we proposed that the plant Cu homeostasis machinery controls the level of Cu in the xylem, preventing it from becoming elevated to a level that would lead to bacterial inhibition.


Talanta ◽  
2022 ◽  
Vol 236 ◽  
pp. 122856
Author(s):  
Juan José López-Mayán ◽  
Sergio del-Ángel-Monroy ◽  
Elena Peña-Vázquez ◽  
María Carmen Barciela-Alonso ◽  
Pilar Bermejo-Barrera ◽  
...  

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Fadi N. Barrak ◽  
Siwei Li ◽  
Albert M. Muntane ◽  
Julian R. Jones

Abstract Background With increasing numbers of dental implants placed annually, complications such as peri-implantitis and the subsequent periprosthetic osteolysis are becoming a major concern. Implantoplasty, a commonly used treatment of peri-implantitis, aims to remove plaque from exposed implants and reduce future microbial adhesion and colonisation by mechanically modifying the implant surface topography, delaying re-infection/colonisation of the site. This in vitro study aims to investigate the release of particles from dental implants and their effects on human gingival fibroblasts (HGFs), following an in vitro mock implantoplasty procedure with a diamond burr. Materials and methods Commercially available implants made from grade 4 (commercially pure, CP) titanium (G4) and grade 5 Ti-6Al-4 V titanium (G5) alloy implants were investigated. Implant particle compositions were quantified by inductively coupled plasma optical emission spectrometer (ICP-OES) following acid digestion. HGFs were cultured in presence of implant particles, and viability was determined using a metabolic activity assay. Results Microparticles and nanoparticles were released from both G4 and G5 implants following the mock implantoplasty procedure. A small amount of vanadium ions were released from G5 particles following immersion in both simulated body fluid and cell culture medium, resulting in significantly reduced viability of HGFs after 10 days of culture. Conclusion There is a need for careful evaluation of the materials used in dental implants and the potential risks of the individual constituents of any alloy. The potential cytotoxicity of G5 titanium alloy particles should be considered when choosing a device for dental implants. Additionally, regardless of implant material, the implantoplasty procedure can release nanometre-sized particles, the full systemic effect of which is not fully understood. As such, authors do not recommend implantoplasty for the treatment of peri-implantitis.


2021 ◽  
pp. 232020682110157
Author(s):  
Abdolrasoul Rangrazi ◽  
Amirtaher Mirmortazavi ◽  
Reyhaneh Imani ◽  
Davood Nodehi

Aim: The aim of this study was to evaluate the effect of the ozonated water on corrosion of a cobalt–chromium (Co-Cr)-based alloy, which is applied for the fabrication of metal frameworks of removable partial dentures. Materials and Methods: In this in vitro study, a total of 30 disk-shaped samples of a Co-Cr alloy were papered and randomly divided into two groups of 15 specimens. In group 1 (control), the specimens were stored in distilled water (DW), and in group 2, the specimens were stored in ozonated water. Around 90 immersions were performed, and the weight change of each specimen was determined. The ion release was analyzed using an inductively coupled plasma-optical emission spectrophotometer. The potentiodynamic polarization test was performed for each group to assess the corrosion resistance of the Co-Cr alloy. The statistical analysis was performed using SPSS version 22. Data were analyzed by independent samples’ t-test. Results: The results showed no significant difference between the weight changes of the two groups. The test using an inductively coupled plasma-optical emission spectrophotometer demonstrated no significant difference between the groups in Co and Cr ions release. In the potentiodynamic polarization test, both groups present similar corrosion behavior, and ozonated water has no deleterious effect on the corrosion resistance and passive range of the Co-Cr alloy compared to DW. Conclusion: As compared to DW, ozonated water has no significant deleterious effect on the corrosion resistance of the Co-Cr frameworks and can be used for cleaning the removable partial dentures.


Author(s):  
S. Adibnia ◽  
Ali Nemati ◽  
Mohammad Hosseien Fathi ◽  
S. Baghshahi

The main purpose of this study is to prepare and characterize hydroxyapatite (HA)–10%wt bioglass (BG) composite nanopowders and its bioactivity. Composites of hydroxyapatite with synthesized bioglass are prepared at various temperatures. Suitable calcination temperature is chosen by evaluating of the phase composition. X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) techniques are utilized to characterize the prepared nanopowders. The bioactivity of the prepared composite samples is evaluated in an in vitro study by immersion of samples in simulated body fluid (SBF) for predicted time. Fourier transformed infrared (FTIR) spectroscopy and inductively coupled plasma (ICP) are used for evaluation of apatite formation and the bioactivity properties. Results show that HA-BG composite nanopowders are successfully prepared without any decomposition of hydroxyapatite. The suitable temperature for calcination is 600°C and the particle size of hydroxyapatite is about 40-70 nm. The apatite phase forms after 14 days immersing of the samples in SBF. It could be concluded that this process can be used to synthesize HA-BG composite nanopowders with improved bioactivity which is much needed for hard tissue repair and biomedical applications.


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