The Stabident System of intraosseous anesthesia

The November 1996 issue of Dental Economics carried a couple of articles that reminded me of a splendid talk I heard some years ago at the Hinman Dental Meeting. First, Dr. Barry Polansky`s article, "Are We Violating Patient Trust Through Poor Time Management?" emphasized that time management is life management. He detailed 12 of his ideas to help us apportion our time more intelligently and prudently.

May 1st, 1997

Most of us never stop to thoughtfully and truly discover how long we take to do routine procedures.

Dr. Myer Leonard

The November 1996 issue of Dental Economics carried a couple of articles that reminded me of a splendid talk I heard some years ago at the Hinman Dental Meeting. First, Dr. Barry Polansky`s article, "Are We Violating Patient Trust Through Poor Time Management?" emphasized that time management is life management. He detailed 12 of his ideas to help us apportion our time more intelligently and prudently.

The late philosopher, Bertrand Russell, once said, "I don`t know what intelligence is, but certainly one component of it must be the ability to allot to each endeavor the appropriate time for that endeavor."

The other article that provoked my memory was one by Linda Miles. She emphasized the need not to keep patients waiting more than 10 minutes and, if you do, then it is the duty of a staff member to apologize and offer an explanation.

These two articles reminded me of the talk Ms. Miles gave some years ago at the Hinman. She asked her audience (several hundred dental assistants and office personnel) how long their doctor thought he took to prepare a crown. She invited members of the audience to raise their hands, as she called out various times estimated by the doctor to do a crown prep. At 25 minutes, a few hands went up; at 30 to 35 minutes, the majority of hands shot up; and at 45 minutes, nearly everyone had raised their hand. Then she asked staff members to raise their hands as she called out the number of minutes they knew the doctor actually took.

At 25 minutes, there wasn`t a hand up; at 30 minutes, possibly two or three hands were raised; and then they all began to laugh. They realized that Ms. Miles had demonstrated, in a very simple manner, the difference between perception and reality - the doctor`s perception and the staff`s reality! At 45 minutes, a lot more hands went up and nearly everyone had raised their hands by the time she got to 50 to 55 minutes for a crown prep.

Soon after that talk, I decided to ask a number of colleagues how long they took to achieve effective anesthesia prior to the extraction of a mandibular molar (since extractions are all I do, I didn`t want to cloud the issue by asking about cavity preps, etc.). I was struck by the nearly uniform answer of three to five minutes. Together, with some of my colleagues (three residents), we timed the period from the injection of the solution until the patient was ready for the extraction. We found were taking a lot longer than three to five minutes. A perusal of the dental literature also shows reported ranges to be from seven to 17 minutes. That obviously is a lot longer than three to five minutes.

Most of us are in dentistry to make a living and, as it is with most occupations, whether it be general dentistry, fixing garages or plumbing, the way in which we make a living is to match our intention with our performance. If you think it takes 10 minutes to place an occlusal amalgam restoration from beginning to end and, in fact, it takes 15 minutes or longer, then this improper assessment will negatively impact on the smooth running of your schedule.

Most of us never stop to thoughtfully and truly discover how long we take to do routine procedures - we just assume we know. It is a salutary and humbling exercise.

Dr. Gordon Christensen, I`m told, estimates it costs about $4 per minute to run a practice. That would seem to make it pretty imperative that you have a good knowledge of how long it takes to do each procedure, because the more things get out of kilter, the more frazzled everyone`s nerves be-come, the more frequent the mistakes, the more irate the patients become, and, ultimately, the higher the turnover of staff - i.e., "the hassle ain`t worth the candle."

I have indicated one area of fairly common misinformation, and that is the local anesthetic time. A relatively new system of intraosseous anesthesia - the Stabident System - is fairly easy to learn, has high patient acceptability, low morbidity, with a high (90+ %) success rate, and, most assuredly, reduces the "down time" from injection to anesthesia.

The armamentarium consists of a 27-gauge needle, 9 mm long, which is used to deliver the anesthetic solution. If, for example, you wanted to prepare a restoration or crown or even extract a maxillary first molar or maxillary bicuspid, you apply topical anesthetic to the gingival tissue, distal to the tooth in question. Place the material about 5 or 6 mm from the gingival margin, still on the attached gingival tissue. After about 20 to 30 seconds, that area should be sufficiently numb to allow you to puncture the site with the short needle and deposit about 0.2 cc of solution subperiosteally. Again, the site chosen is 5 mm from the gingival margin, which previously has been anesthetized.

After a further 20 to 30 seconds, you can use the 9 mm length, 0.43 mm wide sharp-ended, but solid, perforator. This is attached to a handpiece and applied to the site anesthetized. It rapidly perforates the buccal bone between the roots and, because of its short length, will not perforate the palatal bone (see drawing above).

The hole now is identified by a small blob of blood and the syringe can be manipulated, so that the short needle easily enters the perforated site and slowly - over 40 or more seconds - the remainder of the cartridge can be injected into the bone. About 10 seconds after the withdrawal of the needle, the tooth is anesthetized and ready for dental treatment. Even if you were doing an extraction, no palatal injection would be necessary. Dr. Dillon, the inventor, has told me that he places the solution distal to the cuspid and that he can prepare restorations or crown preps on either the cuspid, the lateral, or the central. This obviates the need for an infra-nasal injection. It is not sufficient anesthesia for extraction of those teeth, but may well be effective enough for cavity and crown preparation.

The speed of anesthesia is, of course, due to the deposition of the solution virtually on the superior alveolar nerve. In the usual practice, the solution is deposited in the buccal sulcus, and then must diffuse through the periosteum of the maxilla, then through the very thin and permeable wall of the maxillary bone, before encountering the branches of the superior alveolar nerve. In this technique, the solution is placed directly on the nerve and the time spent in waiting for diffusion is saved. In addition, there appears to be little or no labial anesthesia.

In the case of the mandible, the same procedure is adopted. If, for example, one had to prepare a cervical cavity in the first molar and both bicuspids, that would frequently mean anesthetizing the tongue and lip. It could take up to 10 minutes or more before adequate anesthesia would permit you to begin preparation of the cavities, which would take only a few minutes.

If you had a patient who needed both the right and left sides treated, it`s unlikely that the patient would be excited about having a bilateral lingual block and total labial anesthesia. So the procedure would be done at separate appointments - a total of about 45 to 60 minutes of chairtime to cover about 10 minutes of cavity preparation. Using this technique, there is no lingual anesthesia and, because the inferior alveolar nerve lies in the bony canal, the solution only gets the segments of the nerve that have left the canal and entered the pulps. This probably is the reason why the amount of labial anesthesia is pretty low.

If extractions are to be undertaken, then additional anesthetic solution is needed for the cuff of tissue on the lingual aspect of the tooth.

It`s not easy to gain access to a point distal to the first molar, but I have found that it is possible to bend the injection needle. If it breaks, you should have a pair of fine mosquito clamps in hand to extract the broken segment.

The period of anesthetic using this technique was determined by Coggins to be about 60 minutes. For the vast majority of patients, the procedure is very acceptable, although some people do experience discomfort as the solution is injected. My experience, then, has been to inject very slowly if any discomfort is felt.

Of course, it is essential that no periodontal pocket be present, because injecting into a pocket does not meet the objective of depositing the solution in the bone.

Some patients in Coggins` study had post-injection discomfort for a couple of days. In my study, since all the patients were having teeth extracted and were given about 12 to 15 Tylenol 3 tablets to cover post-extraction pain, this may have masked the post-injection pain, as we didn`t receive any such complaints.

I have been told of a patient who had a segment of bone removed from the site a few weeks later and I`ve also heard of a post-site injection. I have not experienced either of these two problems.

On the other hand, some endodontists have extolled the technique as giving excellent anesthesia for a OhotO tooth.

In short, like most practices, it?s not a 100-percent panacea, but it is another arrow in your quiver. Used with discrimination, it can markedly reduce the Odown timeO waiting for effective anesthesia, as well as obviate frequently uncomfortable and occasionally painful injections and their attendant nuisance effects of lingual and labial anesthesia.

For those interested in learning more about this technique, the company supplies a video, which I strongly recommend viewing prior to starting the technique.

The author is a professor in the Division of Oral and Maxillofacial Surgery at the University of Minnesota and head of Oral and Maxillofacial Surgery at Hennepin County Medical Center. Neither Dr. Leonard nor the clinic in which he is employed receive any discounts, favors, or inducements to use any particular material or techniques, including the Stabident System of Intraosseous Anesthesia.

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