Magnification in endodontics by dr jagadeesh kodityala
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Magnification in endodontics by dr jagadeesh kodityala
- 1. Dr. Jagadeesh K Second yr p.g Dept of Conservative Dentistry & Endodontics MAGNIFICATION IN ENDODONTICS
- 2. Contents • Introduction • History • Optical definitions • Loupes • Dental operating microscope • Rod lens endoscope • Ora scope • conclusion
- 3. INTRODUCTION • Significant advances in the use of magnification and illumination and supportive armamentarium in recent years have benefited treatment protocols in non surgical and surgical endodontics. • Such that teeth, which might otherwise have been extracted, now have a predictable chance for retention.
- 4. HISTORY • Otologists - Introduced operating microscope • In 1922 Carl Nylen - Monocular microscope • In 1953 Carl Zeiss - Binocular operating microscope • In 1960 - 1st surgical operating microscope
- 5. • In 1978 Apothekar & Jako - DOM • In 1981 - DOM (Dentiscope) • In 1993 - Symposium on microscopic Endodontic surgery • In 1995 - DOM by Endodontists • In 1997 - Microscopy training
- 6. DENTISCOPE
- 7. Optical Definitions • Working Distance: The distance measured from the dentist’s eye to the treatment field being viewed.
- 8. • Depth of Field: Refers to the ability of the lens system to focus on objects that are both near and far without having to change the loupe position.
- 9. • Field of view : The area that is visible through Optical magnification. • Viewing angle: The angular position of the optics allowing for a comfortable viewing position for the operator.
- 10. Loupes • Dental loupes are the most common magnification system used in dentistry. MULTI LENS OPTIC SYSTEM • Galilean optical system. (ideal magnification 2.5X) • Keplarian optical system. (ideal magnification 6X)
- 11. An example of a Galilean system Prism loupes. These loupes have sophisticated optics, which rely on internal prisms to bend the light.
- 12. • The disadvantage of this arrangement is that the eyes must converge to view an image. • This convergence over time will create eyestrain and fatigue.
- 13. • Prism loupes produce better magnification, larger fields of view, wider depths of field, and longer working distances than other types of loupes. • Only the Dental Operating Microscope (DOM) provides better magnification and optical characteristics than prism loupes.
- 17. Dental Operating Microscope (DOM) • Most microscopes can be configured to magnifications up to × 40 and beyond but limitations in depth of field and field of view make it impractical.
- 18. Classification Based on use : • Surgical microscope • Examination microscope
- 19. Based on magnification: • Lower magnification (2.5x to 8x) • Midrange magnification (8x to 14x) • Higher range magnifications (14x to 30x) Grossman’s Endodontic Practice 12th ed
- 20. Based on installation Ceiling mounted Floor mounted Wall mounted
- 21. THE ANATOMY OF THE OPERATING MICROSCOPE • 3 primary components: • Supporting structure • Body of the microscope • Light source
- 22. Supporting structure Distance between the fixation point and the body of the microscope is stability
- 23. Body of the microscope • Eyepieces • Binoculars • Magnification changer • Objective lens
- 24. Eyepieces Eyepieces - Rubber cups - Diopter settings from -5 to +5 Eyepieces (6.3x, 10x, 12.5x, 16x, and 20x)
- 25. Binoculars Adjustment of the inter pupillary distance Straight Inclined Inclinable tubes
- 26. Straight Inclined Inclinable tubes Binoculars
- 27. • 3-, 5-, or 6-step manual changers • Manual & Power-zoom changer. • located within the head of the microscope Magnification changer
- 29. Power zoom changer microscopes have foot controls, which allow the surgical field to be focused and magnified hands-free.
- 30. Objective lens Determines operating distance Focal length ranges from 100 – 400 mm Many endodontic surgeons use a 200mm lens, which focuses at about 8 in.
- 31. How surgical operating microscope works ??? Magnification Illumination Instrumentation Documentation
- 32. Magnification • Power of the eyepiece • Focal length of the binoculars • Magnification changer factor • Focal length of the objective lens
- 33. • Total magnification of a microscope: TM = (FLT/FLOL) × EP × MV FLT: Focal length of binocular tube FLOL: Focal length of objective lens EP: Eyepiece Power MV: Magnification Value
- 34. Power of the eyepieces Focal length of the binoculars Magnification factor Magnification Field of view
- 35. Focal length of the objective lens Magnification Illumination Magnification Depth of field Illumination
- 36. • It is important to keep in mind that maximum magnification is used to check, and most of the procedures are made at minimum-medium magnification.
- 37. Illumination Xenon bulb (100watt) Width of light field 45 mm Separation of the light beams Stereoscope effect COAXIAL ILLUMINATION
- 38. Galilean optics. Parallel optics enables the observer to focus at infinity, relieving eyestrain.
- 39. Accessories Beam splitter Separation of light beam Function of beam splitter
- 40. • Assistant scope. • Condenser • Documentation tools: video camera • Strobe on objective lens • Eye piece with reticule
- 41. Documentation Quality slides and video proportional to quality of magnification & illumination Advantages: • Communicate with referring dentist • To educate patients and students • To maintain required legal documentation
- 42. • Postural: posture should be perfect. avoids tiring of eyes. no need of wearing prescription eye wear. • Procedural: improves manual abilities. collateral vision decreases. Procedure recording can be done. procedural errors can be assessed.
- 43. • Psychological: Decreases psychological, physical, Postural stress. Increases personal and professional satisfaction. • Educational: Easy for us to gather images to file. Procedures can be recorded and can be presented in symposia and conferences.
- 44. • Shanelec and Tibbets[1998] – Working without magnification, can make movements that were 1–2 mm at a time. – At 20× magnification, the refinement in movement s can be as little as 10–20 microns (10–20/1000 of a mm) at a time. Tibbets LS, Shanelec DA. Periodontal Microsurgery. Dent Clin North Am. 1998; 42:339–359.
- 45. • Leknius and Geissberger, [1995] and Zaugg et al. (2004): – As magnification is incorporated, procedural errors decrease significantly. – The inclusion of a microscope resulted in fewer errors than when a set of loupes was used. Zaugg B, Stassinakis A, Hotz P. Influence of Magnification Tools on the Recognition of Simulated Preparation and Filling Errors. Schweiz Mo natsschr Zahnmed. 2004; 114(9):890–896.
- 46. Improved & Ideal treatment Ergonomics • All stooping and bending is eliminated • Constant bending collapses the diaphragm
- 47. THE LAWS OF ERGONOMICS • Class I motion: moving only the fingers
- 48. • Class II motion: moving only the fingers and wrists
- 49. • Class III motion: movement originating from the elbow
- 50. Class IV motion: movement originating from the shoulder
- 51. Positioning the DOM • Operator positioning • Rough positioning of the patient • Positioning of the OM and focusing • Adjustment of the interpupillary distance • Fine positioning of the patient • Parfocal adjustment • Fine focus adjustment • Assistant scope adjustment.
- 52. Operator Positioning • At the 11- or 12-o’clock position • 9-o’clock position comfortable when first learning to use an DOM • The hips are 90˚ to the floor, the knees are 90˚ to the hips, and the forearms are 90˚ to the upper arms • The patient is moved to accommodate this position.
- 53. Once the ideal position is established lower magnifications to locate the working area The image is focused and stepped up to higher magnifications if desired.
- 54. Rough positioning of the patient The patient is placed in the trendelenberg position and the chair raised until the patient in focus
- 55. Positioning of the OM and focusing • Knowing the focal length of the objective lens, the operator moves the microscope up and down until the working area comes into focus.
- 56. Fine positioning of the patient • Little movements can be done for the definitive position of the patient. • Maxillary teeth - horizontal • Mandibular teeth - trendelenberg position
- 57. Parfocal adjustment • The focused view of the working area will stay sharp as the magnification is changed. • It is mandatory that working area in focus to the operator, it is also in same focus to the assistant, for the video camera.
- 58. Operatory Design Principles for using DOM • The organizing design principle using the OM - circle of influence.
- 59. Disadvantages • Need for specific training: as a DOM has a restricted working field, 11mm -55mm • An operator using a DOM can see only the tip of the instruments, and they are used in delicate movements of small amplitude • High initial cost of the equipment and instruments
- 60. Use of Dental Operating Microscope • Conventional endodontics: • Preserving tooth substance • Localization & visualization • Locating Calcified Canals • Final examination • Removal of fractured instruments • Obturation with warm gutta-percha • Recognition & location of fractures
- 61. • Surgical Endodontics: • Soft tissue management • Root end procedures (apicoectomy with retrograde filling) • Intentional Replantation
- 62. • Preserving tooth substance: • Trephination opening eg. MB2 canal • Localization & visualization: • Ultra sonic • Appropriate magnification
- 63. • Locating calcified canals • Specially….. • Root Dilacerations • Mid root bifurcations / trifurcations / sharp demarcations of curvature
- 64. Removing fractured instrument: • Traditional methods – perforations - Gross destruction • Operating microscope / ultrasonic tips/ High magnification Recognition & location of fractures: • High magnification • Fracture identified - Methylene Blue
- 65. Perforation repair: • Pro root MTA • Micro instruments & ultrasonic attachments Other Applications • Removal of posts • Cleaning of canals • Handling vital tissue
- 66. Rod–Lens Endoscope Made up of rods of glass working in junction with a camera, light source, and monitor Greater magnification than that achieved with loupes or a microscope, with optical resolution comparable with that of microscopes and/or loupes. The use of the endoscope is therefore recommended for visualization of surgical endodontic treatment.
- 67. • 2.7 mm lens diameter, 70 deg angulation, 3 cm length rod–lens, are recommended for surgical endodontic visualization • 4 mm lens diameter , 30 deg angulation, and 4 cm length rod–le ns for non-surgical visualization through an occlusal access opening. • Hemostasis of the surgical field must be obtained • Eliminate the fogging effect
- 68. Orascope 0.8 mm tip diameter and 0 deg lens and the working portion is 15 mm in length A canal must be prepared to a minimum size of a 90 file in the coronal 15 mm of the canal. If the canal is under-instrumented, a wedging of the orascope may damage some of the fiber optic bundles within the scope. allows the orascope to provide imaging of the apical third
- 71. CONCLUSION • Endodontic procedures can be done in less time because of the greater visibility of the root canal anatomy and procedural errors can be reduced ‘You can only treat what you can see’
- 72. REFERENCES • Richard Rubinstein. Magnification and illumination in apical s urgery. Endodontic Topics; 11 (1), pages 56–77, July 2005. • Detsch S , Cunningham W , Langloss J. Endoscopy as an aid t o endodontic diagnosis. J Endod 1979: 5: 60–62. • Held S , Kao Y , Well D. Endoscope – an endodontic applicati on. J Endod 1996: 22: 327–329 • Bahcall JK , Di Fiore PM , Poulakidas TK. An endoscopic tech nique for endodontic surgery. J Endod 1999: 25: 132–135.
- 73. • Gary B. Carr, Carlos A.F. Murgel. The Use of the Operating M icroscope in Endodontics. Dent Clin N Am 54 (2010) 191–214 • Grossman’s endodontic practice 12th ed • Ingle text book of endodontics 6th ed • Pathways of Pulp- cohen 10th ed
Editor's Notes
- Traditional endodontics has been based on feel not sight. Together with radiographs and electronic apex locators this blind approach has produced surprising success. There is, however, a significant failure rate, especially in long-term. Magnification helps the user not only to see more, but to see well.
- Loupes are essentially two mono-ocular microscopes with lenses mounted side by side and angled inward (convergent optics) to focus on an object. Most dental loupes used today are compound in design and contain multiple lenses with intervening air spaces. This is a significant improvement over simple magnification eyeglasses but falls short of the more expensive prism loupe design. Prism loupes: are actually low-power telescopes that use refractive prisms.
- Low range Magnification: (×2.5 - ×8). Orientation of surgical field & allows wide inspection of the field of view. Mid range Magnification: (×8 - ×14). Surgical procedure including curettage of the granulation tissue, resection of root tip, root –end preparation, & root –end filling. High range Magnification: (×14 - ×30). Observing the finer details & documentation purposes.
- The end of each eyepiece has a rubber cup that can be turned down for clinicians who wear eyeglasses. Eyepieces also have adjustable diopter settings. Diopter settings range from -5 to +5 and are used to adjust for accommodation, which is the ability to focus the lens of the eyes. Diopter setting is particularly important when an assistant scope and documentation equipment are used, so that everything is uniformly in focus (par focalled). It is suggested to check the diopter settings frequently. If documentation accessories are used, the eyepiece which is on the same side of the accessory should be provided with a “reticule” that will help to keep the images well centered in the field.
- The binoculars contain the eyepieces and allow the adjustment of the interpupillary distance. Their focal length is 125 or 160 mm. They are aligned manually or with a small knob until the two divergent circles of light combine to effect a single focus. Once the diopter setting and interpupillary distance adjustments have been made, they should not have to be changed until the microscope is used by a surgeon with different optical requirements. Binoculars are available with straight, inclined, or inclinable tubes. Straight tube binoculars are orientated so that the tubes are parallel to the head of the microscope. They are generally used in otology and are not well suited for dentistry. Inclined tubes are fixed at a 45° angle to the line of sight of the microscope .The inclinable tubes are adjustable through a range of angles and allow the clinician to always establish a very comfortable working position. It is therefore obvious that, even if more expensive, the inclinable binocular is always to be preferred.
- Manual step changers consist of lenses that are mounted on a turret that is connected to a dial located on the side of the microscope.The magnification is altered by rotating the dial. A power zoom changer is a series of lenses that move back and forth on a focusing ring to give a wide range of magnification factors. Focusing with a power zoom microscope is performed by a foot control or by a manual override control knob located on the head of the microscope. The advantage of the power zoom changers is that they avoid the momentary visual disruption or jump that occurs with manual step changers as the clinician rotates the turret and progresses up or down in magnification. The disadvantages are the following: the excursion from the minimum to the maximum magnification is quite slow, while it is must faster with the manual step changers; the number of lenses is much higher compared to the manual step changers, and this means a greater absorption of light; power zoom changer are much more expensive.
- Illumination with the DOM is coaxial with the line of sight. This means that light is focused between the eyes in such a fashion that you can look into the surgical site without seeing any shadows Two light source systems are commonly available: halogen light and xenon light. The halogen light frequently does not provide enough illumination for quality documentation especially at higher powers. The xenon light is much more powerful and provides a brighter light at about 5,000° Kelvin approximating day light. In both cases the light intensity is controlled by a rheostat and cooled by a fan. After the light reaches the surgical field, it is reflected back through the objective lens, through the magnification changer lenses, and through the binoculars and then exits to the eyes as two separate beams of light. The separation of the light beams is what produces the stereoscopic effect that allows the clinician to see depth of field.
- To supply the light to documentation tools Global Surgical Corporation makes a “Virtual Beam splitter”, which splits the light in a ratio of 95% to 5% instead of the traditional 50/50 . The split is done by having a totally reflective coating across a small area of the beam splitter, while the remaining area of the beam splitter is completely transmissive. This implies that the primary surgeon receives 100% of the light across the large area of the beam splitter, and the camera receives 100% of the light across the small area of the beam splitter. In practice, the amount of light received by the virtual beam splitter is enough for the assistant scope or for the video camera, but it is not enough for the 35 mm camera.
- Condenser reduces the illumination field size.
- The principle posits that all instruments and equipment needed for a procedure are within reach of either the clinician or the assistant, requiring no more than a class IV motion, and that most endodontic procedures are performed with class I or class II motions only . The principle assumes that the most ergonomic way to work is to perform all procedures under the OM, including the diagnostic examination, oral cancer screening,anesthesia, and rubber dam placement. Therefore, the circle of influence design principle places the OM at the center of the operatory design, and all the ergonomic movements necessary to work with this technology are centered within those circles.
- Differentiation is defined as making something distinct or specialized.