The value of high magnification in clinical medicine (via a surgical microscope) has been well known for more than 50 years.1 The value of high magnification in dentistry (via a dental operating microscope) has been well known for 20 years in endodontics,2 for 14 years in periodontics3 and for over 10 years in restorative dentistry.4 The benefits of the dental operating microscope with regards to improved ergonomics and enhanced clinical abilities and efficiency have been well established5,6 (Figs. 5 & 6). As well, the value of the dental operating microscope as a diagnostic, documentation and patient education instrument are well established.7,8
Using the dental operating microscope, endodontic procedures are typically performed at magnifications ranging from 2.5X (access) to 20X (exploration, surgery, etc.), periodontal microsurgeries from 10X to 20X, dental technology from 10X to 20X and restorative dentistry from 2.5X to 19X. The actual steps and range in magnification depends on the type of microscope used and the components used and so may vary.
Let’s consider some information about dental magnification.9
| Magnification | Resolution |
| Unaided human eye | 200u (microns) |
| 2.5X loupes | 100u |
| 4X loupes | 50u |
| Sharp explorer | ~40u |
| 8X microscope | 25u |
| 10X microscope | 20u |
| 14X microscope | 14.3u |
| 20X microscope | 10u |
The value of high magnification in clinical applications has been well established and should be axiomatic based on the previous information. Yet at this moment there is still a fair amount of resistance among restorative dentists with regards to the value of high magnification and incorporating the dental operating microscope into their practices. Why aren’t restorative dentists routinely using the dental operating microscope? Given the preponderance of information to the contrary — why do most restorative dentists believe that naked eye vision or low magnification vision is good enough for restorative clinical dentistry?
Many of these same dentists who are resistant to the use of high magnification in restorative dentistry regularly use low level magnification (loupes). But they consider it irrational or unreasonable to use a microscope for restorative dentistry and have proffered many well worn justifiers as to why they can’t or won’t use high magnification. The list that follows (from a personal communication with Dr. Glenn van As) is by no means complete but does give a glimpse into the most common reasons why the dental operating microscope has not enjoyed greater acceptance among restorative dentists. Similarly it also describes why most restorative dentists continue to believe that naked eye vision or low magnification are sufficient to successfully handle clinical work. This list may be used as well to describe the resistance typical to any type of advancement:
* I’m too old to change
* I am just starting out
* I don’t want to see my work up close
* I already do great work
* My patients will feel claustrophobic
* My lab doesn’t do use a microscope
* I can’t charge enough to make it worth while
* I am too fast
* It will slow me down
* It will cost me time
* My back doesn’t bother me
* It costs too much
* There is too big a learning curve
* It won’t work in my town
* It will make my eyes tired
* My 2.5X loupes are all I need
* It just gets in my way
* My staff wont like it
* My assistants can barely keep up with what I am doing now
* I don’t have time to teach more to my assistants
* The insurance companies won’t pay for it
and…..
* my spouse wants a BMW.
While this list of justifiers may appear absurd it is a collection of real statements gathered from dentists attending introductory microscope training courses, participating in dental internet forum discussions on high magnification or evaluating dental operating microscopes while attending dental meetings. These justifiers represent perceived truth in the minds of the dentists interviewed but in reality they are indicators of an unwillingness to confront some of the realities of microscope usage. (Fig. 7. Courtesy Dr. Glenn van As).
Many dentists including the author have had some or all of these same considerations about using a microscope for restorative dentistry. Yet because of the apparent and axiomatic benefits of high magnification these same dentists have chosen to persevere and go through the growth, training and learning process required for the successful integration of the dental operating microscope into a restorative dentistry practice.
The benefits of the dental operating microscope in restorative dentistry have been well chronicled. One of the most recent applications of high magnification to restorative dentistry has resulted in the first systemic classification of tooth cracks and fractures. Unlike previous attempts to classify tooth cracks and fracture this work by Dr. David Clark10 also considered the significance and potential consequences of cracks caused by intracoronal restorations. Most of these types of cracks are not visible without high magnification (16X) and would therefore go undetected even with loupes. This is a classic example of how the information collected by the use high magnification is essential to everyday restorative dentistry (Figs. 1 & 2).
Restorative dentists spend most of their practice time replacing existing, failing restorations. Many times we are converting failing intracoronal alloy restorations into new composite or porcelain restorations or even full coverage porcelain restorations.11 The keys to a successful succedaneous bonded porcelain or composite restoration is healthy tooth structure to bond to and good bonding technique. Good, healthy tooth structure seems fundamental to bonded restorations but without the high magnification and excellent visualization provided by the dental operating microscope there can often be errors of omission (Figs. 3 & 4). Naked eye dentistry (no magnification) or typical loupes (low magnification) do not provide the excellent visualization that the dental operating microscope does. It is axiomatic that dentists working without any magnification are more likely to leave decay than if they did use magnification. The use of the dental operating microscope also allows the dentist to identify, classify and successfully handle any cracks in the dentin and enamel. This has tremendous bearing on the diagnosis, selection of the restoration to be used as well as the outcome of the treatment.
Over the last three years the use of the dental operating microscope in dentistry has doubled.12 This strong growth in usage has been driven by dentist’s desire to improve their dentistry. The use of magnification has also been identified as one of the best ways to improve the quality of dentistry virtually overnight.13 It is the author’s opinion that the use of the dental operating microscope has already started a revolution in with regards to diagnosis, treatment and quality control in restorative dentistry. While this revolution will not be as encompassing as the one created in endodontics by the use of the dental operating microscope it will nonetheless change the face of restorative dentistry with tremendous benefits for clinicians and patients alike.
Like any technology there is a learning curve and training and application are essential. Getting a
dental operating microscope and actually using it is an investment and a commitment. Obviously there is a financial investment, but there is also an investment and commitment to be the best you can be, provide the best dentistry you can provide for you and your patients. Dr. Gary Carr’s often quoted line “You cannot treat what you cannot see” refers to errors of omission. In restorative dentistry, as well as all aspects of dentistry, no magnification or low magnification can easily lead to errors of omission due to lack of complete information. The dental operating microscope goes a long way towards handling this insufficiency of information and the potential sequelae.
The dental operating microscope-its truth is self evident.
Dr. Arturo R. Garcia maintains a private practice in Wayne, PA, with a focus on microscope assisted aesthetic and neuromuscular dentistry.
Oral Health welcomes this original article.
REFERENCES
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3.Shanelec, DA, Tibbetts LS. Periodontal microsurgery, CE couse, 78th AAPO annual meeting, Orlando, FL., Novemeber 19, 1992.
4.Leknius C, Geissberger M. The effect of magnification on the performance of fixed prosthodontic procedures. J Calif Dent Assoc. 1995 Dec; 23 (12): 66-70.
5.Rucker, LM. Surgical magnification: posture maker or posture breaker? Ergonomics and the dental care worker. Washington, DC: American Public Health Association, 1998:192-206.
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9.Carr, GB. Magnification and Illumination in Endodontics. Clarks Clinical Dentistry 4:1-14, 1998.
10.Clark DJ, Sheets CG, Paquette JM. Definitive diagnosis of early enamel and dentin cracks based on microscopic evaluation. J Esthet Restor Dent 15:391 -401, 2003.
11.Garcia, AR. Dental magnification: a clear view of the present and a close up view of the future. Compend Contin Educ Dent. June 26(6A Suppl): 459-463, 2005.
12.Technology: The buzz in the dental office. Dental Product Report Survey. Dec: 42-45, 2005.
13.Miller, MB. Reality 2006 Annual Edition. Vol. 19, 2005. P. 720.
