igh-Speed Drilling...
Iatrogenic Damage Due to High Speed Drilling
merican Academy of Biological Dentistry; Carmel Valley, May 6-9 1987 Iatrogenic Damage Due to High speed Drilling by Dr. Ralph Turk, DDS Germany
Reports by the WHO on the increase in chronic diseases are alarming!
According to them, these diseases have increased threefold over recent years alone. Environmental and civilization damage, such as stress, faulty diet, narcotics, alcohol, etc., also play a part in the figures given by these statistics. Even if stress, stimulants and habit-forming luxuries have increased, this still is not sufficient explanation for the immense rise in the number of persons affected. Especially as cited both by the cheap press and more serious publications, many people are trying to keep fit through physical training and reasonable nourishment.
These efforts on the one hand and the increasing consumption in stimulants plus the accompanying stress on the other should, viewed statistically, balance each other out. If, in spite of this, such a horrendous increase in chronic diseases can be observed then WE, as physicians and dental specialists, are called to check whether our professional operations do not also contribute to the fact that the number of chronically affected persons is increasing to such a devastating extent through the provocation of focal conditions. Every medical discipline has its inherent capacity to cause iatrogenic damage.
The dental field covers such a wide range that I am not able to report on all forms of iatrogenic damage. I would like you to think merely of the sequels of erroneous articulations, reflected, or incorrectly performed, maxillary regulation, as well as badly fitted dentures or prostheses, fillings which are too high causing premature contact, fillings or pulp protection resulting in slow modification of the pulp, or mouth voltages produced by using different metals or alloys etc.. All these forms of istrogenic damage can result in severe negative effects on the general health of the patient.
I would like to encourage thought about forms of damage which have not been taken in sufficient consideration up tonow, or those that might have been noticed, but have been deliberately ignored.
In the context of dental surgery, the primary and, indeed, princ ipal consideration is the dental turbine or roor. In my opinion and also, that of several university clinics, this should be considered as a sort of time bomb! It's devastating effects, have been completely underestimated by most of our colleagues.
AThe industry has propagated the ergonomic advantages of this high-speed drills, constantly developing and more functions; and without long-term clinical, histological or pathological monitoring of the effects of turbines in general, the entire dental profession, including universities, has adopted these diabolical machines.
How do turbines cause damage?
1. In the effects of grinding and drilling burs on the tooth enamel. The turbine does not grind down in the manner of slower machines, but rather breaks up the enamel prisims by impact, not only on the edes of cavities and preparations but also far down into the enamel supposed to remain intact: this has been proved by samples recorded through electron microscope. The cracks thus caused not only allow bacterial toxins but also the bacteria themselves and macromolecules to pass and penetrate in the dentine. This encourages caries.
2. But the major damage is caused in and on the dentine itself. Many colleagues are of the opinion that the pulp receives too much heat due to friction when turbines are used in treatment. Additional abundant cooling would avoid such a burden. As, due to the high rotation speed, both a congestion and
negative pressure occurs on the dentine, a dry (or water-less) zone is formed at the very point of drilling or grinding/milling.3. In an edition of a German-language journal (the ZWR), SCHOLER, a Swiss colleague described trials with air and water-cooler turbines: to culminate, he discovered that already after 5-20 seconds of milling or grinding with turbines, an increase in pulp temperature by 12 degrees C (aboaut 22 degrees F0 caused irreversible damage in 60%d of the pulps examined. These findings have found their confirmation in an almost identical study by HENNING and PRZTAK, who are also mentioned in the same article. This article, however, did not mention one kind of damage which is not produced thermally, but equally spell doom to the pulp, (i.e., damage from negative pressure).
As a result of the high rotation speed, turbulence are produced around the burs which produces a very high negative pressure over the dentinal tubules (according to my own most recent tests this amounts to as much as a 10 mm water column per 100,000 revolutions). This negative pressure does not increase in linear, but in exponential fashion: as a result of this state, the peritubular dentine linings, and the cylindrical odontoblastic processes are damaged or sometimes torn out, even odontoblast cores may be partially sucked into the tubules.
(See right: Dentinal tubules under high power magnification).
Professor RAVNIK of Ljubljana in Yugoslavia was already able to prove this many years ago. This means that the metabolic processes in the enamel and dentine regions are disrupted decisively.
By way of reminder:
Approximately 5 million dentinal tubules per square centimeter (equivalent to 12 million per square inch) are located in the crown area of the pulp. This number decreases down towards the root apex, although it still amounts to approximately 1.4 million at the cement limit. One single dentinal tubule has a diameter of 1.3 to 4.5 microns.
When the drilling or grinding bur is withdrawn, so that the negative pressure ceases, the empty and now open tubules can be filled in a retrograde manner by bacteria and grinding debris, as reported in English Language electron microscope studies. The denatured protein of the destroyed odontoblastic processes and cores can be broken down porteolytically by these bacteria.
Dr. D. L. Cook • 10971 Clinic Road • Suring, Wisconsin 54174 USA
Tel: (920) 842-2083 • Fax: (920) 842-4203