In 1978, Drs. Harvey Apotheker and Geza Jako developed the first
dental operating microscope. This microscope, known as a
Dentistcope, had a single magnification of about 7X.1 Dental
microscopy has seen its greatest expansion into the field of endodontics
when the use of microscopes became the standard of care in graduate
teaching programs in 1998.2 The use of the dental operating microscope
in anatomic discovery of the pulp chamber, retreatment, instrument
removal and perforation repair has been well documented.3,4,5,6
With micro-surgical and minimally invasive procedures already
common in many medical specialties, the natural progression of
microsurgery into the field of periodontics and implant dentistry,
which require greater precision, is understandable. Drs. Rino Burkhardt
and Niklaus Lang’s split mouth clinical comparison study
between micro and macro surgery showed that micro-surgically
treated sites had a lower incidence of post-operative edema and a
higher percentage of vascularization at the surgical site.7 A greater
amount of root coverage was also seen with the microsurgical site.
Later studies by Dr. Luca Franchetti. showed similar results.8
Microscope-enhanced dentistry has been used in cracked tooth
diagnosis, finishing of direct restorations, and preparation and evaluation
of indirect restorations.9,10,11
With the popularity of in-office digital laboratories such as
CEREC and digital work flow techniques, the dental operating
microscope can play a significant role in “precision prosthodontics.”
Using the dental operating microscope, repositioning and completing
the finish lines have been performed with ultrasonic instruments.
12 Whether the final impression is taken with the PVS and
evaluated under magnification, or a digital impression is magnified
eight to 12 times in the digital laboratory software, quality marginal
preparation is key to the fabrication of the final prosthesis.
In our practice, the dental operating microscope is used for
quality control evaluation of all laboratory procedures required for
prosthesis fabrication. These include evaluation of the final impression,
die trimming, wax-up (Fig. 1), crown margin evaluation of all
ceramic crowns before final firing (Fig. 2), final prosthesis evaluation
on the model, and in the patient’s mouth.
In implant dentistry, the microscope can be used to aid in the
fabrication of properly shaped provisional restorations and final custom abutments. Dr. Todd Schoenbaum demonstrated a
method for immediate implant provisional restoration fabrication.
13 In our practice, a dental operating microscope is used to
modify a provisional restoration in a similar fashion (Fig. 3). The
cervical third of the provisional restoration is changed from a convex
profile (Fig. 4) to a concave profile to allow for greater tissue
growth in this critical area (Fig. 5). When the papilla area is viewed
under magnification, it should be pink in color, not red. The red
areas of papilla (Fig. 6) are noted and the provisional restoration is
re-contoured to allow for papilla growth (Fig. 7).
Case Presentation: Single implant crown case in
the posterior region performed with the aid of
a dental operating microscope.
The patient is a 55-year-old woman with a
history of heavy smoking (one pack per day) for
10 years. All other medical history is non-contributory.
She presented with a failing fixed dental
prosthesis on the lower right quadrant (Fig. 8).
Pocket probing revealed a 9mm pocket in the
mid-buccal area of the lower right second molar.
The patient was told that the second molar has a
hopeless prognosis. The patient opted for sectioning
of the existing fixed dental prosthesis, removal
of the hopeless tooth and implant placement in
the first molar region. Preliminary impressions
were taken in alginate using stock rimlock trays
and poured in Type 4 stone (Jade Stone, Whip
Mix). The models were mounted on a semiadjustable
articulator and the missing first molar
tooth was waxed up.
Once satisfied with the occlusion and emergence profile of the
wax-up, the model was duplicated and a radiographic guide was
fabricated using a cold-cured, clear orthodontic resin (Fig. 9). The
radiographic guide was polished and a single 2mm diameter hole
was placed using a tabletop drill through the central fossa of the
radiographic guide. The hole was filled with gutta-percha. The
patient subsequently wore the radiographic guide and a CT scan of
the lower jaw was obtained (Fig. 10).
The location of the dental implant was determined using the
GP point and the distance to the nerve was measured. Before the
implant placement date, the gutta-percha was removed and the
radiographic guide was used as a surgical guide. Normal Nobel
Biocare protocols were followed to place an 11.5mm regular platform
Nobel Replace conical connection implant in the area indicated
by the surgical guide. The implant was torqued to 35Ncm
on placement. A 3mm x 5mm flared healing abutment was placed
and torqued to 15Ncm.
After three months of osseointegration, the healing abutment
was removed and the site was irrigated with chlorhexidine gluconate
0.12%. The dental implant and surrounding tissues were examined
using the dental microscope at 8X magnification to insure there was
no debris inside the implant or around the internal threads (Fig. 11).
Due to the flat tissue profile, it was decided that tissue contouring
with a provisional restoration was not necessary.
A closed tray impression coping was screwed onto the implant.
The microscope was used again and the tissues were gently moved
with the probe to confirm seating of the impression coping (Fig. 12).
A bitewing radiograph was also taken to ensure seating of the impression
coping. An impression was taken with light and heavy body
PVS (Reprosil, Dentsply, York, Pennsylvania). The impression quality
and the seating of the impression coping
within the impression was confirmed with the
use of the microscope at 8X magnification
(Fig. 13). The models were poured and
scanned using a NobelProcera 2G Scanner.
The titanium abutment was designed to
provide the proper emergence profile
expected of a natural molar tooth and support
the final crown (Fig. 14). When the titanium
abutment was received from the
milling center, it was examined for defects
under magnification (Fig. 15). The intaglio
surface of the abutment was highly polished
using titanium polishing cups. The abutment
was steam cleaned and inserted. The abutment
was torqued by hand. The tissue was
checked for blanching using the microscope.
Any areas of blanching were marked and the
abutment was removed and the intaglio surface
adjusted again to insure a concave surface
in the area to allow for tissue health. The
abutment was polished again and steamcleaned.
Once the abutment was placed passively
on the tissues, the abutment screw was
dipped in 2% chlorhexidine gel and was
torqued to 35Ncm. The excess gel was
removed, Teflon tape was placed in the access
hole and the crown was placed on top of the abutment. The crown
was checked for marginal fit and interproximal contact.
The metal ceramic crown (Fig. 16) was designed to hold
Shim Stock in centric occlusion only along with other teeth
in the arch. In eccentric movements, the Shim Stock would disengage.
The polish of the crown was examined under magnification
and any rough areas were smoothened using dialyte
polishing stones. The crown was cemented with RelyX Unicem
Self-Adhesive Universal Resin Cement made by 3M ESPE.
Excess cement was removed under 12X magnification.
The patient was initially given the option of having implant
crowns placed in the first and second molar area. However, the
CT scan revealed a danger to the inferior alveolar nerve if an
implant was placed in the second molar region, and given the
studies suggesting a shortened dental arch is a viable clinical
option, she was advised to receive one implant only.14
The complete seating of impression copings in radiographs
are at times difficult to verify and if an implant is not too submerged,
the microscope is a valuable secondary tool in confirming
There has been great concern regarding the deleterious
effects of remaining cement on the peri-implant tissues.15 One of
the most important uses of the dental operating microscope
comes in cement removal and quality control of marginal
integrity under 12X magnification. While cement-retained
restorations have been questioned lately in literature, a metaanalysis
by Dr. Marcus Brandão et al. shows that peri-implant
bone loss is equivalent between cement retained and screw
retained restorations.16 The choice of cement- versus screwretained
restorations should therefore be based on prosthetic
space available and clinician preference.
The dental operating microscope is an extremely important
tool in every step of the prosthesis design, fabrication and
delivery. The microscope can be used effectively in checking
the seating of the impression coping, confirming the quality of
the final impression, quality control of the fabrication of the
prosthesis, and confirmation of the final delivery of the prosthesis.
With significant concern being raised with excess
cement below the finish lines and the resultant peri-implantitis,
the microscope is a powerful tool in minimizing this troublesome
- Seldon HS. 2002. The dental-operating microscope and its slow acceptance. J. Endod. 28 (3): 206-207.
- Ruddle CJ. 2002. New directions in endodontics. Interview. Dent. Today 21 (2):74-81.
- Selden HS. 1989. The role of a dental operating in endodontics. Pa Dentl. J. (Harrisb.) 53 (3): 36-37.
- Haas R, mensdorff-Pouilly N, Riegler-Thornton B, Watzek G, and Mailath-Pokorny G. 1995. Advantages of microsurgical apicoectomy and retro-preparation with ultrasound compared with current apicoectomy. Fortsch.
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- Reuben HL, and Apotheker H. 1984. Apical surgery with the dental microscope. Oral Surg. Oral Med. Orl Pathol. 57 (4): 433-435.
- Ruddle C. 1997. Endodontic perforation repair: utilizing the operating microscope. Oral Health 87 (12): 21-25.
- 7. Burkhardt R, Lang N. coverage of localized gingival recessions: Comparison of micro- and macrosurgical techniques. J Clin Periodontol 2003; 30:496-504.
- Francetti L, Del Fabbro M, Testori S, Weinstein RL. Microsurgical treatment of gingival recession: A controlled clinical study. Inj J Periodontics Restorative Dent 2005; 25: 181-188.
- Clark DJ, Sheets CG, and Paquette JM. 2003. Definitive diagnosis of early enamel and dentin cracks based on microscopic evaluation. J. Esthet. Restor. Dent. 15 (7): 391-401.
- Piontkowski PK. 1998. The renaissance of dentistry: an introduction to the surgical microscope. Dent. Today 17 (6): 82-87.
- Farr C. 1998. Restoring faith in restorative dentistry: advanced techniques and technology. Dent. Todauy 17 (8): 56-1.
- Massironi D, Pascetta R. Romeo G. 2007. Precision in Dental Esthetics-Clinical and laboratory procedures. Quintessence. Italy. Page 126-127.
- Schoenbaum TR, Chang YY, Klokkevold PR, Snowden JS. 2013. Abutment emergence modification for immediate implant provisional restorations. J Esthet. Restor. Dent. 25 (2): 103-107.
- Armellini D, Von Fraunhofer J.A. 2004. The shortened dental arch: a review of the literature. J Prosthet Dent 92 (6): 531-535
- Wilson TG. 2009. The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. J Periodontol 80(9):1388-92
- de Brandao, ML, Vettore MV, Vidigal GM. 2013. Peri-implant bone loss in cement and screw retained prostheses: Systematic review and meta-analysis. J Clinical Perio 40 (3): 287-295