The primary success metric of dental implants is achieving osseointegration, which is influenced by many factors including implant design, surface treatments, as well as treatment method. Implant drilling is also a major influential factor.
3. Introduction
Albrektsson et al. (1981) suggested that there are 6 factors that determine
the success of osseointegration, that is biocompatibility, design, surface,
state of the host bed, surgical technique and loading conditions.
Especially the effect of surgical procedures such as the drilling protocol has
been sparsely explored, and clinicians basically follow the given
instructions from the manufacturers.
3
6. 6
Hupp JR, Ellis E, Tucker MR. Contemporary Oral and Maxillofacial Surgery. 7th ed.
Philadelphia: Elsevier; 2020.
7. Flap Design
Type of tissue
▣ Full thickness
▣ Partial thickness and
▣ Flapless
The number and type of
incisions
▣ Envelope
▣ Papilla sparing
▣ Triangular
▣ Trapezoidal
▣ Vestibular, etc
7
12. ▣ Template-guided drilling procedure leads to significantly enhanced accuracy.
Significant results compared to free-handed drilling actions were achieved,
irrespective of the clinical experience level of the operator.
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20. Irrigation vs No irrigation
▣ Yacker and colleagues - without irrigation, drill temperatures
greater than 100°C are reached within seconds of the osteotomy.
▣ Benington et al., reported that the osteotomy temperature may
rise up to 130.1°C without irrigation after monitoring changes in
bone temperature during the sequence of drilling for implant site
preparation
▣ 50 mL/min of cooled irrigation of sterile saline (0.9% NaCl)
▣ Distilled water should not be used because rapid cell death may
occur in this medium.
▣ Barrak and colleagues reported that cooling the irrigation fluid
to 10°C, no mean temperature change >1°C will occur.
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21. Graduated versus One-Step Drilling
▣ The amount of heat produced in the bone is directly related to the amount of
bone removed by each drill.
▣ 2mm ˃ 1.5mm
▣ The smaller incremental drill size allows the clinician to prepare the site faster,
with less pressure and less heat generation.
▣ Reduces the drill shatter at the crestal opening, which can inadvertently
fragment the bony crest in which complete bony contact is especially desired.
▣ Maintains the sharpness of each drill for a longer period, which also reduces the
heat generation.
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22. Drilling Speed
▣ Yeniyol et al., showed that excessively low drilling speeds (less than 250 rpm)
increased the degree of fragmentation of the osteotomy edge. It has been
shown that low speed drills will “wobble,” which leads to overpreparation of
the osteotomy site.
▣ The clinician should allow the cutting surface of the drill to contact D1 and D2
bone fewer than 5 of every 10 seconds. Ideally, a pumping up-and down
motion (i.e., bone dancing) is used to prepare the osteotomy and provide
constant irrigation to the drill cutting surface.
D1 and D2 = 1500 - 2000 rpm
D3 and D4 = 1000 rpm
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24. Drilling Time
▣ The slower the rotations per minute (1225), the longer the bone
temperature remained above the baseline.
▣ Because two to three drills are used to prepare an implant site, at 1225 rpm
the
first drill may increase the temperature to 41°C,
the second drill to 45°C, and
the third drill to 49°C, when the time between each sequence is not
extended more than 1 minute.
▣ Therefore to reduce the preparation time within the bone to a minimum in
D1 bone, the clinician should not apply constant pressure to the drill, but
“bone dance” with intermittent pressure for 1 second in the D1 bone and 1
to 2 seconds out of the bone while the cooled irrigation is allowed to
perfuse the site
24
25. Drilling Pressure
▣ The pressure exerted when preparing the osteotomy should not result in
heat generation.
▣ Hobkirk and Rusiniak found that the average force placed on a
handpiece during preparation of an osteotomy is 1.2 kg.
▣ Matthews and Hirsch found that increasing both speed and pressure
allowed the drill to cut more efficiently and generated less heat.
▣ Sufficient pressure should be used on the drill to proceed at least 2 mm
every 5 seconds. If this is not achieved, then new (sharper) or smaller
diameter drills are indicated for each site preparation.
▣ The pressure on the drills should not reduce the rotations per minute,
which makes the drill less efficient and increases heat.
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26. Continuous Drilling
▣ When constant pressure is
applied, irrigation cannot enter the
osteotomy site; therefore this may
result in heat-related damage.
▣ Bone debris is maintained within
the flutes of the surgical burs,
resulting in potential heat
generation. This also leads to less
efficient drilling.
Intermittent Drilling
▣ Less heat generation is seen.
▣ Debris is removed, thus making
the cutting process more efficient.
▣ Disadvantage of the bone dancing
technique is the possibility of
changing angulation or inadvertent
widening of the osteotomy site.
▣ Care should be exercised in
withdrawing and inserting the
implant drill at the same trajectory
or angulation.
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Intermittent versus Continuous Drilling
27. Insertion Torque
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▣ The force used to insert a dental implant into a prepared osteotomy.
▣ Expressed in units of N/cm, which ultimately determines the loading
protocol.
▣ IT is the primary most important factor in determining primary
stability.
▣ Ideal for implant integration = 35 - 45 N/cm
▣ To standardize the amount of torque, calibrated torque wrenches,
physiodispenser instruments with integrated electronic torque control
settings, and preset torque settings on the implant electric motor
systems should be used.
49. 49
Misch’s Contemporary Implant dentistry – 4th edition
Block & Kent’s Endosseous Implants For Maxillofacial
Reconstruction
ADA council on scientific affairs Dental endosseous implants. An
update. JADA, Vol. 135, January 2004.
Shadid, R.M., Sadaqah, N.R. and Othman, S.A., 2014. Does the
implant surgical technique affect the primary and/or secondary stability of
dental implants? A systematic review. International journal of
dentistry, 2014.
Sharawy, M., Misch, C.E., Weller, N. and Tehemar, S., 2002. Heat
generation during implant drilling: the significance of motor
speed. Journal of Oral and Maxillofacial Surgery, 60(10), pp.1160-1169.
References
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Tehemar, S.H., 1999. Factors affecting heat generation during
implant site preparation: a review of biologic observations and future
considerations. Int J Oral Maxillofac Implants, 14(1), pp.127-136.
Cavallaro Jr, J., Greenstein, B. and Greenstein, G., 2009. Clinical
methodologies for achieving primary dental implant stability: the
effects of alveolar bone density. The Journal of the American Dental
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Padhye, N.M., Padhye, A.M. and Bhatavadekar, N.B., 2020.
Osseodensification––A systematic review and qualitative analysis of
published literature. Journal of oral biology and craniofacial
research, 10(1), pp.375-380.
Scherer, U., Stoetzer, M., Ruecker, M., Gellrich, N.C. and von See,
C., 2015. Template-guided vs. non-guided drilling in site preparation of
dental implants. Clinical oral investigations, 19(6), pp.1339-1346.