A rationale for the use of high-powered magnification or microscopes in general dentistry
By John S. Mamoun, DMD
Featured in General Dentistry, January/February 2009
Pg. 18-26
Posted on Wednesday, January 07, 2009
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This article argues that high-powered magnification (4x–6x or more) provides substantially more visual information for diagnosing and treating dental pathology compared to the use of unaided vision or entry-level 2.5x magnification. In all phases of general dentistry, the increased visual detail provided by high magnification reduces ambiguity in diagnosis and treatment decision-making, increases control in treatment implementation, allows a dentist to produce more ergonomic restorations that are less prone to recurrent decay, and arguably improves clinical outcomes compared to work performed with unaided vision. High magnification enhances a dentist’s ability to diagnose caries and cracks in teeth, distinguish between different colors intraorally, detect the interfaces between different surfaces and materials, detect microscopic interferences in fixed and removable metal frameworks, adjust occlusal prematurities, and polish restorations. This article explains specific general dental applications for high-powered magnification in restorative dentistry, fixed and removable prosthodontics, endodontics, pediatric dentistry, periodontics, and oral surgery.
Received: June 10, 2008
Accepted: August 11, 2008
Most dentists use the naked eye to acquire visual information when treating patients. It can be argued, however, that in many clinical situations, unaided vision and even low-powered magnification (such as 2.5x) will not provide a dentist with all of the clinically relevant visual information needed to diagnose and treat dental pathology rationally. Tiny visual details cannot be resolved via unaided vision due to the naked eye’s inherent limits of resolution; in addition, dentists must maintain a minimum physical distance of several inches from most of their patients’ teeth, which makes it difficult to resolve minute details.
This article argues that the ability to perceive microscopic details provided by high-powered magnification (4x–6x or greater) may improve a dentist’s ability to deliver optimal dental therapy, which also may quantifiably improve treatment outcomes such as tooth lifespan and patient satisfaction.1-3 This article seeks to provide a comprehensive overview of the applications for high magnification in general dentistry so as to convince dentists that high magnification is a standard of care when performing dental procedures. Finally, this article suggests that all dentists master the use of high magnification as a tool for performing clinical work, even though many may find the learning curve to acquire such mastery to be tedious and time-consuming.
There are several general reasons why high-powered magnification provides more clinically relevant visual information to general dentists than unaided vision. Dental caries is a disease that originates at the microscopic level. It is associated with microscopic risk factors such as tiny plaque or food traps and features microscopic manifestations of disease, including thin demineralized grooves, tiny discolorations on a tooth surface, and pinpoint breaks in tooth structure that may lead to extensive decay. High magnification reveals these aspects of dental caries. Intraoral prosthetic devices have minimal tolerance of fit and microscopic interferences may prevent crowns, bridges, and removable partial denture frameworks from seating fully. These interferences may be located on the metal understructures of fixed or removable prostheses; they also may result from subtle convexities or undercuts on the teeth where these prostheses are to be seated.
High magnification improves a dentist’s ability to differentiate between subtle shades of color intraorally, which is important when diagnosing and treating dental pathology. Magnification also allows dentists to differentiate between the interfaces of two different materials seen intraorally (for example, between wedges, matrix bands, and the margins of preparations; teeth and alveolar bone during extractions; composite and natural tooth structure; core buildup material and the margins of crown preparations; or excess acrylic resin flash and tooth structure).
The touch receptors on the tongue are capable of sensing microscopic textures on intraoral surfaces, while proprioceptive nerves in the periodontal ligament are capable of sensing occlusal discrepancies and high spots on a microscopic scale. To remove microscopic restoration discrepancies, high-powered magnification should be utilized when adjusting occlusion or polishing a restoration. High-powered magnification also may reveal clinically relevant microscopic details in tooth anatomy, particularly concerning root canal anatomy or tiny tooth cracks.
Magnification, like rubber dam isolation, helps to isolate the operating field visually, making a tooth occupy most of the dentist’s field of vision and excluding other distracting or irrelevant visual details. Finally, loupes or microscopes with a long working distance allow dentists to maintain a longer distance from the patient during dental work, improving the dentist’s posture and reducing the risk of exposure to aerosols and spatter.4
Examination, diagnosis, and treatment planning
High magnification can aid in examining, diagnosing, and treatment planning; in addition, high magnification in combination with a microscope or loupes attached to a digital camera makes it possible to document a patient’s dental condition.5 It allows a dentist to locate tiny, clinically relevant discolored areas on a tooth (for example, within transilluminated Class III interproximal surfaces) and to detect tiny gaps in restorations or crowns when using an explorer.
Magnification can reveal tiny plaque traps, such as those found on the distal grooves of maxillary second molars. Upon seeing this risk factor for decay, the dentist will know to remove the overlying plaque to look underneath it for signs of decay or demineralization. Magnification makes it easier to read periodontal probe measurements, see subtle areas of gingival inflammation or subgingival calculus, and locate deep periodontal pockets (including isolated deep pockets around teeth that may indicate abscess drainage pathways).
High magnification is essential for diagnosing dental caries. Sometimes a microscopic blemish, color alteration, or trace of demineralization on the tooth surface is the only sign of caries. High magnification makes it possible to detect these microscopic signs of decay on a tooth surface and diagnose the carious lesions that sometimes are referred to as hidden caries.
Carious lesions that feature microscopic demineralization along microscopically thin fissures or pits would not be visible radiographically, because these lesions are contained within a matrix of mostly healthy, mineralized tooth structure, which appears radiopaque on radiographic film. These lesions often cannot be detected with the traditional explorer stick; however, high-powered magnification allows dentists to identify tiny amounts of plaque collecting within the grooves, microscopic amounts of chalky white demineralization around the grooves, and tiny amounts of flaking of darkened carious tooth structure within the crevices of these grooves.
Other carious lesions may be identifiable with an explorer stick but sometimes only a tiny pinpoint spot within the larger lesion will show such a stick. Magnification enables dentists to detect the tiny color or texture difference between this pinpoint spot and the rest of the (intact) tooth surface overlying the carious lesion and determine where precisely to point the explorer to locate the explorer stick.
Some carious lesions cannot be seen radiographically or diagnosed with an explorer stick. These lesions can be diagnosed only by the color difference between the carious lesion and the surrounding healthy tooth structure. Carious lesions that develop under what appear to be intact tooth surfaces can demineralize the underlying tooth structure, causing subtle color changes that are visible at the part of the tooth surface overlying the carious tooth structure. Often, these color differences are too subtle to see using the naked eye (and can be further obscured by the overhead operatory light casting a shadow along the tooth surface) and become more obvious when high magnification is utilized.
Some examples of discoloration of carious tooth structure in the author’s experience include marginal ridges that feature a shimmering, rainbow-colored opalescence (which may indicate marginal ridge caries), an intact tooth surface where the underlying dentin seems to be a chalky white or chalky beige color (suggesting extensive sub-surface demineralization), a hardened (remineralized) pinpoint on a tooth surface with dark sub-surface caries (giving the enamel around the pinpoint a diffuse, greyish-blue color), and hardened brown pit lesions with several different white or beige color shades within the lesion (suggesting that there are different microscopic degrees of carious activity and carious demineralization within the same lesion). Since the topic of diagnosing carious lesions based on color is not well-developed scientifically, dentists using a microscope will need to rely on experience to detect carious lesions based on color.
Operative dentistry
When performing operative dentistry, dentists can use high magnification to see the subtle color contrasts between carious and healthy tooth structure on a microscopic scale. Class III or Class II proximal box preparation margins (Fig. 1) show minimal color contrast between carious and non-carious tooth structure; high magnification allows dentists to see tiny slivers of caries along the margins of preparations. Magnification facilitates caries detection when tooth walls are viewed from a perspective that causes the walls to appear foreshortened (for example, when viewing the proximal box walls in Class II preparations). When a slow-speed round bur is used to excavate decay, magnification enables dentists to better see the tiny flakes of carious tooth structure churned up by the bur along the undercuts and overhangs of the inner walls of tooth preparations. Magnification makes it possible to see the dimensions of carious lesions systematically, which in turn allows dentists to create a more ergonomic restoration design, one in which the margins of the restoration do not end on plaque traps or on demineralized or carious tooth structure.
High magnification is helpful in assuring dentists that caries has been entirely removed from the margins of the future restoration; this information is useful when premolars or primary teeth have deep caries that are close to the pulp and the dentist wishes to leave and seal in a tiny amount of the caries overlying the pulp to avoid the risk of pulpal exposure. High magnification also makes it easier to distinguish between the color of a composite and natural tooth structure when removing old composite restorations.
When restoring tooth preparations with filling material, dentists can use higher magnification to determine if the restoration material is condensed into all of the preparation’s tiny line angles, undercuts, and proximal box surfaces. Dentists can better detect which aspects of a preparation are too narrow or pointed to allow for adequate condensation of restorative material and widen or otherwise reshape these aspects to facilitate adequate condensation. Among other things, this reshaping can prevent a pinpoint plaque trap from developing at the margin of the mid-buccal groove aspect of an amalgam on a mandibular molar.
Higher magnification enables dentists to design preparations so that all aspects of the subsequently placed restoration (especially the marginal aspects) are under compressive forces rather than shear forces. In addition, the higher magnification enhances dentists’ ability to see gaps between restorative material and preparation margins and allows them to see subtle amounts of moisture contamination on preparation walls (or within the body of the restorative material), blood or gingival tissue seeping under proximal box matrix bands, and excess pooling of bonding agents when making composite restorations.
High magnification allows for precise detection and adjustment of the interproximal curvatures of Class II restorations, and for detecting and removing unsupported interproximal Class II restorative material under excess shear forces. Dentists also can verify that matrix bands are burnished properly and that the proximal box aspect of the matrix band touches the interproximal surface of the neighboring tooth.
Higher magnification allows dentists using the total-etch technique to see if acid-etching produces a frosty white texture on all aspects of a tooth surface that is due to receive a sealant or a composite restoration. When preparing teeth for composite restorations, dentists can better see the boundary between the cervical aspect of the preparation margins and the gingival margin, which would reduce gingival bleeding, the risk of blood contamination, and the possibility of gingival injury during tooth preparation (Fig. 2). Higher magnification also makes it easier to determine visually if adequate undercuts exist within a preparation to allow for the mechanical retention of restorative material.
Increased magnification makes it easy to identify overhangs and rough areas when polishing composite or amalgam restorations. It also allows dentists to identify precisely which of the irregularities on a composite restoration surface (for example, shadowing or morphological or color asymmetries) may affect the overall appearance of the restoration when it is viewed with the naked eye. High magnification allows dentists to be more precise when moving a polishing bur along the contours of teeth. It also can assist dentists in locating tiny crumbs of amalgam or other restorative materials so that they can be suctioned out of the mouth and tiny chunks of bonding agent or composite that may have polymerized on other intraoral surfaces.
Fixed prosthodontics
High magnification is useful when preparing crown and bridge abutments and seating restorations.6 Microscopic undercuts in crown and bridge preparations can greatly compromise the seating of the restorations, even when an excellent final impression is taken. A laboratory may attempt to block out such undercuts with excess die spacer but doing so may lead to excess cement space or space between the crown and the preparation. Under high magnification, undercuts in crown preparations are more obvious, as are rough and pitted areas on preparation walls that may be difficult to see with unaided vision. The author prepares teeth using 4x loupes magnification and switches to 6x loupes magnification to detect and remove microscopic undercuts from the preparations.
When evaluating the undercut of a crown preparation, dentists must examine the preparation by looking at it downward and parallel to the axis of the path of insertion of the future crown. As a result, the preparation walls may appear foreshortened. High-powered magnification improves a dentist’s ability to comprehend the dimensions of surfaces that appear foreshortened in the viewing perspective. Therefore, dentists can more easily determine if the margin of the preparation is completely visible in a viewing perspective that is parallel to the path of draw of the future crown (Fig. 2 and 3).
When assessing bridge preparation undercuts, dentists often may choose which aspects or line angles of the bridge preparation should be reduced to eliminate undercuts. Magnification offers greater control to dentists who choose to eliminate undercuts in the bridge’s path of draw by drilling more into core build-up restorative materials within bridge preparations, rather than into tooth structure.
High magnification (particularly when used in combination with head-mounted illumination) makes it easier for dentists to see the interproximal aspects of tooth preparations while reducing them. As a result, dentists are better able to avoid injuring the interproximal gingiva when preparing the teeth, thus reducing the potential for gingival bleeding, which would compromise the integrity of the final impression. Dentists also are more likely to see carious lesions within teeth while preparing them for crowns, making it possible to eliminate these lesions and to prevent caries from developing underneath the future crown.
High magnification also aids in detecting and removing flash at the margins of preparations with feather-edge margins, “ski slopes” (that is, subtle upward curving at the edges of shoulder margins, caused by the dentist failing to move the flat surface of a cylinder diamond all the way to the edge of the margin) at the edges of shoulder margins, and roughness along the surface of shoulder margins. When dentists desire to pack cord, magnification makes it possible to direct the force vectors that push the cord into the sulcus with greater precision. In addition, dentists can better examine final impressions for defects or undercuts and estimate whether triple tray bites are inaccurate and therefore require a separate bite registration.
Magnification also is useful for adjusting the occlusion of crowns and bridges. When a patient occludes into a bridge during a try-in session, magnification allows the dentist to see any subtle dislodging leverage forces on the abutments during intercuspation. This sort of leverage imbalance is suggested when subtle microscopic movement or flow of saliva is noted at the bridge margin of one abutment but not at another. The dentist can adjust the bridge to alleviate the imbalance. He or she also can detect tiny, obstructive metal spheres on the internal surfaces of crowns, uneven textures suggesting a miscast, tiny undercuts or inward “curling” of metal at the inner surfaces of crowns at the cementoenamel junction (CEJ) aspect, or excess porcelain or glaze at the CEJ aspect of crowns, each of which can be adjusted to reduce the hindrance in seating the crowns.
Magnification allows dentists to sense if a large gap exists between the crown and the preparation when attempting to pass an explorer tip between them. When adjusting porcelain on the crown, dentists can more easily determine if the opaquing layer is becoming exposed due to adjustments. Once the crown is seated, it is easier to detect and remove excess cement. In addition, when using a scaler to flick off excess cement, it is easier to avoid poking or lacerating the gingiva.
The combination of high magnification and head-mounted illumination is particularly useful when cutting off old crowns or bridges. Dentists can better distinguish between the porcelain and the underlying metal coping of the crown, between the metal coping of the crown and the (metallic) amalgam core buildup material, and between the porcelain and the cement of the crown. A magnified view of the contours of the segmented (but still attached) pieces of the crown indicates whether the pieces are held in place with undercuts (and therefore require more sectioning) or if they can be separated with an instrument used as a wedge. The magnified view also makes it easier to determine if the metal crown coping has been cut completely in two at the gingival aspect.
Removable prosthodontics
When adjusting fixed or removable dentures, magnification allows dentists to see undercuts on the acrylic intaglio surface that could irritate the edentulous ridge, making it possible to assess the complete and even seating of a metal partial denture framework to within fractions of a millimeter. Magnification also can be used to detect subtle border overextensions in custom trays and sense where the borders of custom trays or finished dentures interfere with the range of movement of intraoral muscles (particularly the mentalis muscle) or frena. With magnification, subtle redness or hyperkeratosis in edentulous ridges that indicate sore spots can be detected more efficiently and marked (using an indelible marker) more precisely so that the marker does not bleed dye onto non-traumatized aspects of the edentulous ridge surface.
Pediatric dentistry
Primary teeth are best viewed under high magnification, particularly when accessing tiny primary canals during pulpotomy procedures. Given that primary teeth have an intrinsically small volume of tooth structure, magnification also facilitates the conservation of primary tooth structure when performing restorative or pulpotomy procedures. Magnification improves the dentist’s ability to distinguish between the subtle color contrasts of carious and healthy primary tooth structure. In addition, if a child refuses needle anesthesia prior to drilling, magnification makes it possible to determine—within a fraction of a millimeter—which aspects of the tooth elicit pain and to avoid these aspects as much as is practical.
Periodontics
High magnification aids in detecting supra- and subgingival plaque and calculus biofilms. Dentists can see tiny spicules of calculus more easily and distinguish between the color of calculus and the color of the tooth surface. Dentists also can move the tips of cavitron or scaler instruments more precisely along the contour of the tooth surface to remove calculus and can verify the location of thin brown stains on teeth to a microscopic degree. High magnification also makes it easier to detect subtle areas of gingival inflammation (for example, at the interproximals of maxillary molars or at the mesial margins of mesially inclined teeth).
A magnified view of the supragingival root surface or the supragingival emergence profile of a tooth also enables a dentist to visualize the contour of the unseen, subgingival root surface more precisely, improving the dentist’s ability to determine if the entire subgingival root surface has been cleaned and to orient the cutting surfaces of scalers or cavitron tips more precisely to clean all aspects of the subgingival root surface. Dentists using unaided vision may not be able to visualize the subgingival root contour adequately; by contrast, dentists who use magnification may be able to clean an aspect of a root surface that has never been cleaned before. Magnification also improves a dentist’s ability to perceive fine details in periodontal surgery and allows for more precise suturing of periodontal flaps.7-9
Oral surgery
When extracting a tooth, dentists can use high magnification to sense and fully exploit all of the potential purchase points of the straight elevator. Dentists can sense subtle or microscopic differences in the angles and directions of tooth movement while luxating. These differences could indicate the existence of multiple different purchase points, some of which may be only fractions of a millimeter apart. Knowing these differences allows dentists to exploit each purchase point and make the eventual forceps extraction as systematic as possible.
For surgical extractions, magnification enables dentists to distinguish more efficiently between tooth structure and the surrounding bone, to locate the junctions between roots with greater precision, and to determine (to a fraction of a millimeter) which aspects of alveolar bone prevent extraction of a tooth or root, even when blood may hinder visibility of the extraction site. Magnification allows for more accurate and conservative sectioning of tooth or bone and for more accurate placement of elevator instruments at the interface between bone and tooth. After extracting a tooth, dentists can use magnification to detect tiny amounts of granulation tissue, bleeding, loose particles of bone, sharp bony protrusions, contaminants within a socket, or subtle bleeding due to sinus perforations.
High magnification improves a dentist’s ability to see the different colors or surface textures of an intraoral lesion. Oral surgeons using high magnification can see the borders between an intraoral lesion and normal tissue more precisely, which facilitates complete removal of the lesion when performing an excisional biopsy.
Endodontics
The use of high magnification or microscopes is established among endodontic specialists and a full exploration of this topic is beyond the scope of this article.10-15 Briefly, general dentists can use 4x or 6x loupes (and even microscope magnification) to improve visibility and efficiency when performing endodontic treatment, particularly during molar and premolar root canals (Fig. 4).
Magnification also allows dentists to better identify anatomical landmarks within the pulp chamber—including the sides, overhanging walls that are remnants of the pulp chamber roof, and initial perforations into the pulp—and to differentiate between the pulp horns and the main body of pulp within the chamber. Magnification aids in locating the mesiobuccal-2 canal and other accessory canals of maxillary molars.
Dentists also can identify (to within a fraction of a millimeter) which aspects of the pulp chamber walls prevent endodontic files from making straight line access to specific canals and which ones block files from maneuvering into specific canals. This ability allows for more conservative removal of tooth structure to improve endodontic access. Magnification also allows dentists to better see and remove decay within the tooth that is receiving endodontic treatment, including decay existing in undercut areas within the tooth structure.
During instrumentation, the improved ability to see specific canals allows dentists to maneuver files into canal openings with greater efficiency, to distinguish between vital and necrotic canals, and to detect tiny amounts of purulence or blood draining through specific canals. Dentists sometimes can directly see tiny amounts of necrotic pulp material that were not removed during canal instrumentation. When dentists cannot directly see where a file enters into a canal, magnification makes it possible to determine the canal into which a file is placed, based on the angle of the file as it emerges from the access opening and the point where the file touches the rim of the access opening. As a result, it is possible for a dentist to determine if all canals are accessed and instrumented when a direct view might be difficult or when the dentist would have to remove excessive amounts of coronal tooth structure to acquire such direct vision.
Magnification allows dentists to maneuver paper points and gutta-percha cones more efficiently into canal openings and to see if all canals have been obturated. Using magnification to view the angles of gutta-percha cones as they emerge from their respective root canals makes it possible to determine which canals contain gutta-percha cones. This determination is useful if a root canal sealer floods the chamber and prevents direct visualization. When lateral condensation is used to obturate the canals, magnification allows dentists a better view of the tiny access opening produced by a finger spreader; in addition, it is easier to see and clean away excess gutta-percha and root canal cement along pulp chamber walls or the margins of future core build-up materials.
Occlusal adjustment
The proprioceptive nerves of the periodontal ligament around tooth roots are sensitive to microscopic occlusal prematurities in newly placed restorations or crowns. Imperfect adjustment of these prematurities can prevent complete intercuspation and lead to short- or long-term symptoms of hot and cold sensitivity. High magnification assists dentists in identifying an intraoral occlusal contact point, which can be used as a reference when adjusting newly placed restorations, even if patients have tight lip muscles that hinder visibility of such points.
High magnification also helps dentists to detect excess separation at a reference point where two tooth surfaces normally are separated slightly, even in maximum intercuspation. High magnification facilitates detection of restoration high spots that make very subtle marks on articulating paper or consist of a subtle shiny area in a newly placed amalgam. When the articulating paper gives false positive or false negative results, magnification allows dentists to see prematurities directly, even on a hard-to-see lingual cusp surface.
Diagnosis of cracked teeth
When a patient reports that a tooth is sensitive to chewing but the tooth does not have a high restoration with an occlusal prematurity and there is no obvious endodontic problem, the dentist should consider that the sensitivity may be due to misdirected occlusal forces that may be causing cracks or craze lines on a tooth (Fig. 5 and 6). High magnification is essential for seeing cracks or craze lines that are too subtle to see with unaided vision and for helping dentists to determine the cause of general sensitivity (pulpal pathology, high restoration, or a crack) while chewing.16,17 Magnification allows dentists to see more precisely which aspect of a tooth is occluding into a point on an opposing tooth where there are signs of occlusal damage. These signs could include cracks in teeth or restorations, craze lines (cracks in enamel but not necessarily dentin), wear facets, cracks at slightly elevated marginal ridges, or areas where the enamel has been worn by opposing porcelain, exposing dentin and thus causing sensitivity.
Tiny, subtle movements of tooth pieces that have become separated due to a crack are easily visible under magnification. Magnification facilitates treatment of such teeth by allowing the precise elimination of opposing occlusal prematurities and reshaping of the cracked tooth, which in turn allows dentists to redirect or eliminate the harmful sheer or compressive occlusal force vectors that are causing the crack.
Technical considerations when using magnification
When using loupes, the fully adjustable kind are recommended. Adjustable loupes allow dentists to change the interpupillary distance between the magnifying lenses, the vertical height of the loupes, and the angle of the loupes with the nose (that is, the declension angle).18 The working distance and declension angle parameters on the loupes influence the dentist’s posture when working, so the dentist should adjust these two parameters so that they allow him or her to work with good posture.
The loupes should allow the dentist to focus so that there is minimal difference in the contraction of eye muscles, regardless or whether the dentist is using loupes or unaided vision. This focus will prevent eye fatigue due to frequent switching between magnified and unaided vision, as sometimes happens when switching to unaided vision to guide an anesthetic needle toward the point of injection.
Dentists should use head-mounted illumination that allows bright light to always illuminate teeth along the same visual axis of the loupes. This co-axial lighting is useful for endodontic and extraction procedures, for working on the proximal boxes of Class II preparations or the interproximal areas of crown preparations, or for any procedure where an overhead light source may be blocked by instruments, hands, or the dentist’s head. An adjunct to microscopes or loupes is an intraoral mirror with a magnifying mirror surface, which can be attached to a standard intraoral mirror handle and provides additional magnification (Fig. 7). There also are head-mounted microscopes that feature 10x magnification, built-in co-axial illumination, and a built-in digital camera to record procedures while they are being performed.
Dentists using magnification must possess a concept of measurement when viewing objects at the magnified level. Dentists who normally use unaided vision may have developed an intuition for judging the dimensions of intraoral forms such as cavity preparations; however, this intuition may not be useful when dentists are working with the different image sizes and proportions of high magnification. Dentists can overcome this difference by using the dimensions of burs as a measurement reference while working through magnification.
Dentists should remember some measurement values when working under magnification. For example, the cutting end of a 330 bur has a length of 1.5 mm and a width of 0.5 mm, while a 557 bur has a length of 3 mm and a width of 0.75 mm. Dentists also may use a periodontal probe during a procedure as a measuring device.19
Dentists should be aware of clinically relevant measurement facts when working; for example, an amalgam restoration should ideally have a thickness of at least 1.5 mm to withstand biting forces. Dentists may note that the taper of a torpedo diamond represents an ideal taper for a crown preparation, provided the diamond tip is placed at the CEJ of the preparation and the tip is parallel to the long axis of the tooth that is being prepared. This allows dentists to look at the tooth through magnifiers and determine objectively if the crown taper is appropriate.
Summary
High levels of magnification increase the aggregate amount of visual information available to dentists for diagnosing and treating dental pathology, which may allow dentists to develop ways of solving a given dental problem that differ from those used by dentists who use unaided vision. Dentists who use high magnification may be able to develop expertise at an accelerated rate. Dentists who use high magnification may diagnose and treat dental pathology with greater complexity and are more likely to be certain about the causes of a patient’s symptoms, compared to dentists who use unaided vision.
Acknowledgements
The author would like to thank Dr. Donato Napoletano and Dr. Glenn van As for providing some of the photographs used in this article.
Author information
Dr. Mamoun is in private practice in
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