scholarly journals Bracket base remnants after orthodontic debonding

2013 ◽  
Vol 83 (5) ◽  
pp. 885-891 ◽  
Author(s):  
Matteo Zanarini ◽  
Antonio Gracco ◽  
Monica Lattuca ◽  
Silvia Marchionni ◽  
Maria Rosaria Gatto ◽  
...  

ABSTRACT Objective: To evaluate whether the debonding procedure leads to restitutio ad integrum of the enamel surface by investigating the presence of enamel within the bracket base remnants after debonding. Materials and Methods: Sixty patients who completed orthodontic treatment with fixed appliances were included. A total of 1068 brackets were microphotographed; the brackets presenting some remnants on the base (n  =  818) were selected and analyzed with ImageJ software to measure the remnant area. From this population a statistically significant sample (n  =  100) was observed under a scanning electron microscope to check for the presence of enamel within the remnants. Energy dispersive x-ray spectrometry was also performed to obtain quantitative data. Results: Statistically significant differences in the remnant percentage between arches were observed for incisor and canine brackets (P < .0001 and P  =  .022, respectively). From a morphologic analysis of the scanning electron micrographs the bracket bases were categorized in 3 groups: group A, bases presenting a thin enamel coat (83%); group B, bases showing sizable enamel fragments (7%); group C, bases with no morphologic evidence of enamel presence (10%). Calcium presence was noted on all evaluated brackets under energy dispersive x-ray spectrometry. No significant difference was observed in the Ca/Si ratio between group A (16.21%) and group B (18.77%), whereas the Ca/Si ratio in group C (5.40%) was significantly lower than that of the other groups (P < .323 and P  =  .0001, respectively). Conclusion: The objective of an atraumatic debonding is not achieved yet; in some cases the damage could be clinically relevant.

2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.


2019 ◽  
Vol 9 ◽  
pp. 184798041985255 ◽  
Author(s):  
J Adnan ◽  
M Arfan ◽  
T Shahid ◽  
MZ Khan ◽  
R Masab ◽  
...  

Polycrystalline cadmium hydroxide nanomaterials have successfully been synthesized by composite-hydroxide-mediated approach with growth time variation. The influence of growth time on structural, morphological, elemental, and optical properties was explored using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, and ultraviolet–visible spectroscopy. X-ray diffraction results revealed the hexagonal and monoclinic phases of cadmium hydroxide along with rhombohedral impurity phase of cadmium carbonate. Fourier transform infrared spectroscopy further endorsed the X-ray diffraction results and confirmed the Cd–O bonding vibrations. Time-dependent uniform distribution of spherical morphology was observed in the scanning electron micrographs of the product. The presence of cadmium and oxygen in the energy dispersive X-ray spectroscopy results fingerprinted the purity and formation of the desired nanomaterials. Crystallite size was decreased with the increase of growth time as estimated by the Debye–Scherrer method. Furthermore, the optical bandgap was measured by Tauc’s relation using ultraviolet–visible absorption spectra and found to be in the range of 3.2–3.5 eV.


2011 ◽  
Vol 51 (2) ◽  
pp. 73
Author(s):  
Elisa Elisa ◽  
S. H. Purwanto ◽  
A. T. Aman ◽  
Y. Pranoto ◽  
Kusmono Kusmono

Background Reusing endotracheal tubes (EITs) has been performed in Indonesia with no evidence of its safety. Objective To evaluate sterility, as well as the mechanical, surface, and matrix properties of reused EITs following 2 different reprocessing procedures.Methods Reused EITs were cleaned and disinfected, then sterilized by ethylene oxide gas sterilization (group A) or dry heat sterilization (group B). New EITs were used as the standard for comparison. Microbes were identified and microbial counts were determined as colony forming units (CFUs). Evaluation of mechanical properties was perfonned by a Universal Testing machine. All samples underwent tensile and compression tests.Load defonnation curves were recorded from F max and strain at F max. Microstructure analysis was done using X􀁅ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX).Results Positive cultures of commensal bacteria were found in 2/12 samples in group A, and 5/17 samples in group B. T here was no statistically significant difference between them (P =0.07). Pseudomonas aeruginosa or other common pathogens were not found. Samples from both groups showed equal flaccidity, compared to the standard. Surface microstructure analysis of reused EITs 'With XPS and EDX showed degradation of the matrixcomponent. SEM analysis detected some large particles and fissures. EDX analysis on the large particles detected sodium and calcium signals. Altogether, signs of contamination and material damage were very strong.Conclusion Both reprocessing methods of reused EITs gave comparable results on sterility and mechanical behavior, but reprocessing may cause decreased surface and matrix quality. 


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 602
Author(s):  
Xixi Wu ◽  
Changjie Cai ◽  
Javier Gil ◽  
Elizabeth Jantz ◽  
Yacoub Al Sakka ◽  
...  

Titanium particles embedded on peri-implant tissues are associated with a variety of detrimental effects. Given that the characteristics of these detached fragments (size, concentration, etc.) dictate the potential cytotoxicity and biological repercussions exerted, it is of paramount importance to investigate the properties of these debris. This study compares the characteristics of particles released among different implant systems (Group A: Straumann, Group B: BioHorizons and Group C: Zimmer) during implantoplasty. A novel experimental system was utilized for measuring and collecting particles generated from implantoplasty. A scanning mobility particle sizer, aerodynamic particle sizer, nano micro-orifice uniform deposit impactor, and scanning electron microscope were used to collect and analyze the particles by size. The chemical composition of the particles was analyzed by highly sensitive microanalysis, microstructures by scanning electron microscope and the mechanical properties by nanoindentation equipment. Particles released by implantoplasty showed bimodal size distributions, with the majority of particles in the ultrafine size range (<100 nm) for all groups. Statistical analysis indicated a significant difference among all implant systems in terms of the particle number size distribution (p < 0.0001), with the highest concentration in Group B and lowest in Group C, in both fine and ultrafine modes. Significant differences among all groups (p < 0.0001) were also observed for the other two metrics, with the highest concentration of particle mass and surface area in Group B and lowest in Group C, in both fine and ultrafine modes. For coarse particles (>1 µm), no significant difference was detected among groups in terms of particle number or mass, but a significantly smaller surface area was found in Group A as compared to Group B (p = 0.02) and Group C (p = 0.005). The 1 first minute of procedures had a higher number concentration compared to the second and third minutes. SEM-EDS analysis showed different morphologies for various implant systems. These results can be explained by the differences in the chemical composition and microstructures of the different dental implants. Group B is softer than Groups A and C due to the laser treatment in the neck producing an increase of the grain size. The hardest implants were those of Group C due to the cold-strained titanium alloy, and consequently they displayed lower release than Groups A and B. Implantoplasty was associated with debris particle release, with the majority of particles at nanometric dimensions. BioHorizons implants released more particles compared to Straumann and Zimmer. Due to the widespread use of implantoplasty, it is of key importance to understand the characteristics of the generated debris. This is the first study to detect, quantify and analyze the debris/particles released from dental implants during implantoplasty including the full range of particle sizes, including both micro- and nano-scales.


2015 ◽  
Vol 6 (1) ◽  
pp. 20-25
Author(s):  
K Shashikala ◽  
BS Keshava Prasad ◽  
Anukriti Tyagi

ABSTRACT The aim of this in vitro study was to compare the debris and smear layer removal following root canal preparation using two different rotary systems with scanning electron microscope (SEM). The rotary systems used were Protaper and K3. Forty single rooted permanent mandibular premolars were chosen for the study. They were assigned two groups on the basis of instrumentation used. The teeth were sectioned at the level of cementoenamel junction and instrumented with Protaper in group A and with K3 in group B. The root canals were thoroughly irrigated with 5 ml of 2.5 % NaOCl during instrumentation. After instrumentation, 5 ml of normal saline was used as a final rinse. The teeth were split longitudinally and the specimens were prepared for SEM evaluation. Scanning electron microscope photomicrographs showed presence of debris and smear layer. The SEM photomicrographs were scored, based on the standard score rating system, and the scores were tabulated accordingly. The scores obtained from the specimens were subjected to statistical analysis. Results showed opening of dentinal tubules and effective removal of smear layer in group A (Protaper) and no significant difference between both the groups (groups A and B) regarding debris. How to cite this article Tyagi A, Prasad BSK, Shashikala K. Evaluation of Effectiveness of Cleaning of Root Canals using Protaper and K3 Rotary Systems: A Sem Study. World J Dent 2015;6(1):20-25.


Author(s):  
Marcelo Campagnolo ◽  
Ricardo Reis ◽  
Marcele Santos ◽  
Lúcia Kliemann ◽  
Ricardo Savaris

Objective To determine which mode and potency of electrocoagulation, using a modern electrosurgical generator, yields the smallest unobstructed area of the Fallopian tubes. Methods In an experimental study, tubes from 48 hysterectomies or tubal ligation were evaluated. Tubes were randomly allocated to one of the following groups: group A) 25 W x 5 seconds (n = 17); group B) 30 W x 5 seconds (n = 17); group C) 35 W x 5 seconds (n = 18), group D) 40 W x 5 seconds (n = 20); group E) 40 W x 5 seconds with visual inspection (blanch, swells, collapse) (n = 16); group F) 50 W x 5 seconds (n = 8). Bipolar electrocoagulation was performed in groups A to E, and monopolar electrocoagulation was performed in group F. Coagulation mode was used in all groups. Digital photomicrography of the transversal histological sections of the isthmic segment of the Fallopian tube were taken, and the median percentage of unobstructed luminal area (mm2) was measured with ImageJ software (ImageJ, National Institutes of Health, Bethesda, MD, USA). The Kruskal-Wallis test or analysis of variance (ANOVA) was used for statistical analysis. Results Ninety-six Fallopian tube sections were analyzed. The smallest median occluded area (%; range) of the Fallopian tube was obtained in the group with 40 W with visual inspection (8.3%; 0.9–40%), followed by the groups 25 W (9.1%; 0–35.9%), 40 W (14.2; 0.9–43.2%), 30 W (14.2; 0.9–49.7%), 35 W (15.1; 3–46.4%) and 50 W (38.2; 3.1–51%). No statistically significant difference was found among groups (p = 0.09, Kruskal-Wallis test). Conclusion The smallest unobstructed area was obtained with power setting at 40 W with visual inspection using a modern electrosurgical generator. However, no statistically significant difference in the unobstructed area was observed among the groups using these different modes and potencies.


2019 ◽  
Vol 4 (2) ◽  
pp. 102
Author(s):  
Raudhatul Jannah ◽  
Bergman Thahar ◽  
Endah Mardiati ◽  
Ida Ayu Evangelina

Slot bracket base is one important element to enable sliding movement of the archwire. Bracket reconditioning by means of burning changes the surface roughness of slot bracket base. The heat above 450 °C shows microstructure changes of the slot surface. On this basis, the present study aims to evaluate surface roughness changes of the slot bracket base before and after reconditioning by means of burning. Sixteen premolar brackets standard edgewise were divided into two groups each consisting of eight brackets. These two groups were tested at three different points using Scanning Electron Microscopy (SEM), with 3000 times of magnification. Subsequentl,group A was burned for 5 seconds (approximately 450 °C) and group B was burned for 10 seconds(approximately 643 °C). After treatment,these two groups were tested for the second time using Scanning Electron Microscopy (SEM), with 3000 times magnification and the images were analyzed using a discrete scale quantitative classification. Afterwards, the data were analyzed using ANOVA (p≤0.05) and post hoc analysis. The result showed that surface roughness of the slot bracket base burned for 10 seconds experienced more significant change than that of bracket burned for 5 seconds and that of the control bracket(p≤0.05).Bracket reconditioning using burning either for 5 to 10 seconds change the surface roughness of the slot bracket base.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


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