scholarly journals The Next Big Thing is Really Big!! Magnification in Dentistry

2021 ◽  
Vol 10 (15) ◽  
pp. 1083-1087
Author(s):  
Shweta Kishor Sedani ◽  
Anuja Dhananjay Ikhar ◽  
Akshay Pramod Thote
Keyword(s):  
Focal Length ◽  
Treatment Plan ◽  
Surgical Techniques ◽  
Caries Detection ◽  
Objective Lens ◽  
Operating Microscope ◽  
Video Monitor ◽  
Minimally Invasive Surgical ◽  
Dental Procedures ◽  
Adhesive Dentistry

BACKGROUND The advances in the magnification sector have revolutionised the endodontic treatment from tactile and radiograph based to the vision driven. Using magnification tools like loupes, microscopes, rod lens endoscopes and oroscopes in the endodontic practice enables the clinician to magnify the field of treatment further than that by naked eyes. Suitable illumination along with magnification adds to the success of any dental procedure. Dating back to 1870, surgical loupes have been used. Apotheker and Jako introduced microscope in dentistry for the first time in 1978. Carr, in 1992 highlighted the role of the surgical operating microscope in endodontics. Various applications of surgical operating microscopes include minimally invasive surgical techniques like in periodontal regenerative procedures, adhesive dentistry and various procedures in endodontics like caries detection, for hidden canals, pulp stone removal, instrument removal, surgical endodontics, retreatment, perforation seal etc. Parts of operating microscope include optical components, objective lens, binocular tubes, eyepieces, lighting unit and mounting system. Accessories include motorised / foot-controlled adjustment of focal length, mechanical optical rotating assembly (MORA) interface and beam splitter. Magnification aids assist in producing higher quality procedures due to better precision and accuracy. Using the microscope aids improved ergonomics for the operator. Using loupes or microscopes improves the clarity in treatment plan as well as its execution. The magnification aids with camera and video monitor attached, enhance the patient education and better documentation. A strong consideration should be given to adopt using the concept of magnification. This review intended to explain the use of these tools in dental procedures for better accuracy, handling and thoroughness, which will lead to fewer procedural errors. KEY WORDS Magnification, Illumination, Loupes

The Reduction of Chromatic Aberrations Due to Instrumental Instabilities

1971 ◽  
Vol 29 ◽  
pp. 14-15
Author(s):  
J. S. Lally ◽  
R. Evans
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Usual Practice ◽  
Voltage Electron ◽  
Short Focal Length ◽  
Chromatic Aberrations ◽  
Electron Microscopes

One of the instrumental factors often limiting the resolution of the electron microscope is image defocussing due to changes in accelerating voltage or objective lens current. This factor is particularly important in high voltage electron microscopes both because of the higher voltages and lens currents required but also because of the inherently longer focal lengths, i.e. 6 mm in contrast to 1.5-2.2 mm for modern short focal length objectives.The usual practice in commercial electron microscopes is to design separately stabilized accelerating voltage and lens supplies. In this case chromatic aberration in the image is caused by the random and independent fluctuations of both the high voltage and objective lens current.

A Superconducting Microscope

1971 ◽  
Vol 29 ◽  
pp. 10-11 ◽  
Author(s):  
R. E. Worsham ◽  
J. E. Mann ◽  
E. G. Richardson
Keyword(s):  
Liquid Helium ◽  
Focal Length ◽  
Vacuum System ◽  
Objective Lens ◽  
Electrical Instability ◽  
Radiation Shields ◽  
And Control ◽  
Thermal Oscillations ◽  
Flux Pump

This superconducting microscope, Figure 1, was first operated in May, 1970. The column, which started life as a Siemens Elmiskop I, was modified by removing the objective and intermediate lenses, the specimen chamber, and the complete vacuum system. The large cryostat contains the objective lens and stage. They are attached to the bottom of the 7-liter helium vessel and are surrounded by two vapor-cooled radiation shields.In the initial operational period 5-mm and 2-mm focal length objective lens pole pieces were used giving magnification up to 45000X. Without a stigmator and precision ground pole pieces, a resolution of about 50-100Å was achieved. The boil-off rate of the liquid helium was reduced to 0.2-0.3ℓ/hour after elimination of thermal oscillations in the cryostat. The calculated boil-off was 0.2ℓ/hour. No effect caused by mechanical or electrical instability was found. Both 4.2°K and 1.7-1.9°K operation were routine. Flux pump excitation and control of the lens were quite smooth, simple, and, apparently highly stable. Alignment of the objective lens proved quite awkward, however, with the long-thin epoxy glass posts used for supporting the lens.

Improvements in the electron probe forming capabilities and x-ray hole counts in the Philips TEM

1983 ◽  
Vol 41 ◽  
pp. 376-377
Author(s):  
Richard L. McConville
Keyword(s):  
Field Strength ◽  
Electron Probe ◽  
Spherical Aberration ◽  
Focal Length ◽  
Objective Lens ◽  
Parallel Beam ◽  
Tilt Axis ◽  
X Ray ◽  
Small Probe ◽  
Specimen Height

A second generation twin lens has been developed. This symmetrical lens with a wider bore, yet superior values of chromatic and spherical aberration for a given focal length, retains both eucentric ± 60° tilt movement and 20°x ray detector take-off angle at 90° to the tilt axis. Adjust able tilt axis height, as well as specimen height, now ensures almost invariant objective lens strengths for both TEM (parallel beam conditions) and STEM or nano probe (focused small probe) modes.These modes are selected through use of an auxiliary lens situ ated above the objective. When this lens is on the specimen is illuminated with a parallel beam of electrons, and when it is off the specimen is illuminated with a focused probe of dimensions governed by the excitation of the condenser 1 lens. Thus TEM/STEM operation is controlled by a lens which is independent of the objective lens field strength.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

1995 ◽  
Vol 53 ◽  
pp. 584-585
Author(s):  
Uwe Lücken ◽  
Michael Felsmann ◽  
Wim M. Busing ◽  
Frank de Jong
Keyword(s):  
Life Science ◽  
Focal Length ◽  
Objective Lens ◽  
High Contrast ◽  
Contrast Imaging ◽  
X Ray ◽  
Forming Mechanism ◽  
Similar Image ◽  
High Contrast Imaging ◽  
Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

Minimally Invasive Surgical Techniques to Treat Spine Infection S

1996 ◽  
Vol 27 (1) ◽  
pp. 183-199 ◽  
Author(s):  
Larry M. Parker ◽  
Paul C. McAfee ◽  
Ira L. Fedder ◽  
James C. Weis ◽  
W. Peter Geis
Keyword(s):  
Minimally Invasive ◽  
Surgical Techniques ◽  
Spine Infection ◽  
Minimally Invasive Surgical

FUNCTIONAL OUTCOME OF DISTAL FEMORAL FRACTURES AND THEIR MANAGEMENT

2021 ◽  
Vol 5 (6) ◽  
Author(s):  
Raman Shrivastava ◽  
Namita Shrivastava
Keyword(s):  
Functional Outcome ◽  
Surgical Techniques ◽  
Femoral Fractures ◽  
Railway Track ◽  
Distal Femoral Fractures ◽  
Minimally Invasive Surgical ◽  
Fall From Height ◽  
Classification Management ◽  
A Prospective Study ◽  
Jawaharlal Nehru

Background: Fractures of distal end of femur are complex injuries which are difficult to manage. These fractures often are unstable and comminuted. Despite advances in surgical techniques and improvement in implants, treatment of distal femoral fractures remains a challenge in many situations. This study was done to analyse the functional outcome and this management of distal femoral fractures. Material & Methods: This study has been done between August 2008 to March 2010 on patients coming to Orthopaedics Department at Jawaharlal Nehru Hospital and Research Center, Bhilai. It is a prospective study which includes 25 patients with 10 Type A, 7 Type B and 8 Type C fractures of distal femur after fulfilling the inclusion and exclusion criteria. Results: Mean age of 47.08 years with sex incidence of 3.17:1(M:F). Mode of injury was RTA in 16, simple fall in 6, fall from height in 2 and railway track accident in 1 patient. There were 5-A1, 1-A2, 4-A3, 3-B1, 1-B2, 3-B3, 1-C1, 4-C2 and 3-C3 fractures. Results were found to be excellent in 17, good in 1, moderate in 3 and poor in 4 patients. Conclusion: We conclude that minimally invasive surgical techniques and with the availability of locking type of plates distal femoral fractures can now be dealt with more precessions and more satisfactory results can be produced. Keywords: Distal fractures, Muller Classification, Management, Femoral fractures

scholarly journals Surgical techniques: past, present and future

2012 ◽  
Vol 2 (1) ◽  
pp. 9 ◽  
Author(s):  
Karim Qayumi
Keyword(s):  
Middle Ages ◽  
Technological Progress ◽  
Surgical Techniques ◽  
Neolithic Period ◽  
Minimally Invasive Surgical ◽  
Surgical Methods ◽  
Modern Hospital ◽  
The 19Th Century ◽  
Further Development ◽  
Shed Light

The aim of this paper is to provide an analytical survey of the information available on the development of past and present surgical techniques, and to make projections for the future. For the purposes of this paper, the <em>Past</em> starts in the Neolithic period and ends in the 1800s. In this context, I have divided the <em>Past</em> into <em>Prehistoric</em>, <em>Ancient</em> and <em>Middle Ages</em>, and this period ends in the second half of the 19th century when the major obstacles to the further development of surgery, such as overcoming pain and infection, were removed. We will discuss the development of surgical techniques, and the obstacles and opportunities prevalent in these periods. In the context of this paper, the <em>Present</em> begins in 1867, when Louis Pasteur discovered microorganisms, and ends in the present day. There have been many important changes in the development of surgical techniques during this period, such as the transfer of surgery from the unsterile operating room to the modern hospital operating theater, the development of advanced and specialized surgical practices, such as transplants and laparoscopy, and minimally invasive surgical methods, robotic and Natural Orifice Transluminal Endoscopic Surgery. It is very difficult to foresee how surgical techniques will develop in the <em>Future</em> because of the unpredictable nature of technological progress. Therefore, in this paper, the forecast for the <em>Future</em> is limited to the next 50- 100 years and is a realistic calculation based on already existing technologies. In this context, the <em>Future</em> is divided into the development of surgical techniques that will develop in the <em>near</em> and <em>distant</em> future. It is anticipated that this overview will shed light on the historical perspective of surgical techniques and stimulate interest in their further development.

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