Local anesthetic news

  While dentistry continues to shed its old image and like the beautiful peony flower of spring which faithfully reminds us that like the tiny chicken pecks an exit through its shell to freedom, we too shall soon be shedding our cashmere coats and boots to behold endless fields of sheer beauty as spring transitions into summer.

Oral sciences, historically strut their new technologies at their largest shows in the spring each year in Cologne, Germany and
Chicago, Illinois. Dentistry is benefiting tremendously from world wide research and innovative minds.

When was the last time while walking the corridors of a dental/medical building have you heard that shrilling or the blasting burr from a dental drill? Most such procedures are now taken care by laser. It took a little while, but for the records it was Einstein’s law of Relativity and his work on the speed of light showed that gravity had the ability to bend light. That was the beginning of the laser beam.

It is probably more likely to hear waterfalls and to sense the aroma of Asian or Tropical fragrances seeping from dental offices as more and more dentists offer through third parties a “day” of indulging oneself in the spa or a total therapeutic massage work out. 

However there are time when it is necessary to administer pharmaceutical agents (drugs) during dental treatment. The first that comes to mind is the placement of a local anesthetic solution to disguise or numb the presence of pain. It is not unusual for patients to have a low threshold and may manifest a mild allergic hypersensitivity to this solution. At other times such reactions can be as a result of too rapid [ injection should take 45 – 60 seconds ] an injection and finally, a tiny bit of the solution may enter into the vascular system during administration which may cause a faint or light headed feeling.

Most anesthetic solutions do contain epinephrine, the main purpose of which, is to reduce bleeding and to constrict or retain the anesthetic solution in place for a longer period. It is more preferable to have a little numbness persisting after the procedure, than to have the patient regain sensitivity before the work is finished. At times during a lengthy procedure the patient may require a second injection.

The purpose of this article is to draw your attention to an the following article published and referenced under JADA (Journal of American Dental Association) which deals with epinephrine-impregnated retraction cords. 

Epinephrine acts as a vasoconstrictor when used in dental procedures; however it can act as a vasodilator if it is introduced intravascularly or systemically absorbed. Caution is advised when relative high concentration of epinephrine is impregnated into retraction cords. Please consult your dentist. 

DENTAL PRODUCT SPOTLIGHT

Gingival retraction Controlling blood, crevicular fluid, water and saliva while taking impressions is critical. Water and saliva can be controlled by air spray. Blood and crevicular fluid can be controlled by retraction cords, hemostatic agents, electrosurgery or rotary gingival curettage.¹ Retraction cords displace gingival tissue mechanically; they also can have a chemical action when impregnated with astringents and vasoconstrictors that cause tissue contraction and hemostasis. Electrosurgery creates a trough around the tooth by removing superficial cell layers from the gingival sulcus’ inner lining through application of an electric current. Rotary gingival curettage removes the sulcular epithelium with a high-speed diamond bur. Azzi and colleagues² studied the effect of retraction cords, electrosurgery and rotary gingival curettage on gingival recession and loss of attachment in dogs. They found that cords had the smallest effect on the gingiva and rotary curettage had the largest effect. Astringents impregnated in retraction cords include aluminum chloride, ferric sulfate, alum (potassium aluminum sulfate) and zinc chloride. Alum and ferric sulfate may be irritating and even corrosive at high concentrations, while increased concentrations of zinc chloride may damage bone and tissue permanently.³ The least irritating cords contain buffered aluminum chloride, which may be left in the sulcus for up to 15 minutes without permanent damage.⁴ Weir and Williams⁵ reported that soaking retraction cords in aluminum chloride solution enhances hemostasis. This led Runyan and colleagues¹ to study whether soaking cords in aluminum chloride solution has any effect on the ability of the cord to absorb moisture. They found that presoaking had no effect on fluid absorption and, therefore, may be a worthwhile adjunct. Gingival retraction cords containing epinephrine effectively control bleeding; however, from 24 to 92 percent of the epinephrine may be absorbed systemically.⁶ Epinephrine-impregnated retraction cord contains 8 percent racemic epinephrine. One study estimated the concentration of epinephrine absorbed systemically to be equivalent to approximately 3.9 cartridges of local anesthetic containing 1:100,000 l-epinephrine.⁷ This estimate is considerably lower than previous estimates because the authors calculated the actual amount of releasable epinephrine in the cord before retraction, which was found to be approximately one-half that of the labeled amount; based their final estimate on the more biologically active l-epinephrine; and found that presoaking in aluminum chloride removed approximately 25 percent of the racemic epinephrine in the cord. There are conflicting reports on whether epinephrine absorbed from retraction cords has any adverse physiological effects.^7–11 The potential epinephrine reactions that can occur following systemic absorption include increased anxiety after cord placement, limb tremor, diaphoresis, headache, florid appearance, tachycardia and elevated blood pressure.⁶ However, there are many variables that make it difficult to predict the physiological effect. These variables include the concentration of epinephrine absorbed from the cord; the length of time the cord is in the sulcus; the condition of the gingival tissue; the presence of crevicular fluid or saliva; individual patient response; and drug interactions with tricyclic antidepressants, nonselective ß-adrenergic antagonists, certain general anesthetics and cocaine.^10,11 Therefore, recommendations have been made to either limit or avoid use of such epinephrine-impregnated retraction cords.^7,10,11comments to author.  mailto:localanesthetics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.Anestheticnews.com

Summer was once again approaching and while unlike the anticipation and eagerness I usually enjoyed each November, as I journeyed to my
Caribbean retreat for my fix of ultra violet rays, yet there was something almost homeopathic and  calming about the aging hammock with a good book and the almost deathly silence of summer by the lake.

On my usual November trip south, the captain would put us through  the “g force” as he challenged the physics of gravity prior to lift-off. I often thought how Albert Einstein could have ever imagined what it would have been like to travel along side the speed of light when my main concern was focused on whether this de-iced 700,000 lbs monster would continue to gain altitude. However as true to form the falling leaves of red and gold faded into white fluffy cumulus which seemed to be void of density as the shining machine sliced through them as effortless as a knife through butter. There you go.  

Life above the 49^th parallel had lasting memories for me. I lived the best of both worlds. Snow shoveling was replaced by an early walk where I summonsed my younger balancing skills at playing hopscotch through the sharp edged seashells being caressed by each gentle wave. In contrast, summer was spent mostly reclining in a hammock which over the years had formed itself like a large latex glove around my girth with each increasing year.  This posture allowed me together with my book of the day to blend in with the sparsely placed pine furniture in the large and opened verandah which surrounded the cottage on three sides. open and almost oblivious to the distant hum of a power boat on the lake.

Winter, albeit relaxing and therapeutic, was in deep contrast to the silence one experienced on most lakes north of the 49^th parallel. The mere experience for most northern tourists to afford a
Caribbean vacation was seen as a right of passage to gave way to any Freudian inhibition which may have not been completely resolved. In addition, there was the cooling and refreshing rum punch mixtures added to the rhythmic sound of the “steel band” made it a powerful prescription of feeling entitled to shed not only one’s pent-up stress, but at times parts of their already skimpy apparel. This resulting atmosphere is what most scholars of psychology refer to as the emerging passive-aggressive behavior. There you go.

In preparation for my summer retreat during the month of June, I was like the proverbial bull in the china store as I maneuvered my mini shopping cart from aisle to aisle through my favorite book store. This store offered an atmosphere not unlike a trade show with rows and rows of draped individual small tables throughout the aisles which seemed to add that much more square footage to advertise and promote authors and new releases. These arcades and display tables were managed independently by their own sales associates, a title by which they preferred to be addressed. There you go. 

It was noticeably busy for a mid week morning in June. I carefully rechecked my BlackBerry organizer which for the most part tagged along with me like a faithful poodle with its unconditional love. From to time it would vibrate or other times it would emit a childlike whine to inform me of some event I had previously entered and may have completely forgotten about it. I lovingly referred to it as my dementia levee which faithfully protected any memory cells from overflowing my aging brain’s levee. A tap or two on  the sensitive touch screen revealed  nothing exceptional or urgent other than a memo to remind me to make a date to see the movie “Sex and the City” With Sarah Jessica Parker, Kim Cattrall. There you go. 

Why then was this excessive marketing atmosphere so evident throughout the store? Did the book industry secretly generate a Tiger Woods’ moment of mass marketing?  This certainly would have been the best kept secret, yet the solution was facing me right between the eyes. Historically, increased activity at book stores and movie houses has proven to be an accurate and reliable early leading indicator of impending recession as people at large have more free time. Ironically some business benefit from recession in the same way as the demand for steel increases during periods of war. 

Suspense novels are my passion and among others there were two on my short  list – namely “A prisoner of birth” by Jeffrey Archer and “The Pillars of the Earth” by Ken Follet. I also keep in touch and have a burning desire to be current with professional journals and especially editorials which, with some basic writing skills and strategetly placed references can be confused as scientific material. 

Over the many years of reading, I have developed an almost Sherlock Holmes analytical personality for articles. No more so than dentists are impulsively attracted to “the work” on one’s teeth or an architect inspecting the symmetry of a well placed keystone. These editorials/articles can often be detected by the format of their presentation, which is usually in the form of a question rather than the more accepted form of peer reviewed scientific study complete with investigating phenomena or purpose, an accepted methodology protocol and a conclusion. The pure sciences are becoming more and more diluted as such editorials begin their long “hear-say” or gossip walk through the hallowed corridors of famed teaching institutions.  Such articles presented under the guise of scientific material are for the most part self serving and do little to advance clinical efficacy with less unforeseen mishaps.  

However, there are the pundits of an evolving world where analytic jurisprudence is popular and where asking questions like, “What is law?” “What are the criteria for legal validity?” or “What is the relationship between law and morality?” and other such questions that legal philosophers may engage. (Wiki). 

An article this summer caught my attention under the heading of ethics and jurisprudence.  Here goes that question format - “Informed consent for Local Anesthesia - is it necessary?” There is implied dictum which takes the blame away from the operator and places it on a compound (amides) which dentists have been using successfully since 1947 to induce local anesthesia. If ever there was a case for longitudinal and sample size data, our stats people would have a heyday.   

Life styles through all aspects has changed and dental offices were no exception. I was as attentive to my oral health as I was to my physical health and over the  years I had noticed gradual subtle changes such as more pre clinical involvement with hygienists but perception is reality. I also noticed the office in greater detail. The Italian leather couches, slate tile floors and backlit etched glass in the patient lounge, exuded a definite warmth and elegant atmosphere. My dentist was considered to be one of the best, hence the ambience to go with her status. 

From the patient lounge I  was taken into a room with soft music and current magazines like Ophra, Vogue, Sports Illustrated, which all appeared to have been delivered that very morning. The dentist greeted me and after some small talk, asked me to place a tiny pill under my tongue which she explained would dissolve in a few minutes. Her assistant returned in about half an hour and led me into the operatory. By this time I was feeling very relaxed and comfortable.The local anesthetic solution was delivered through a computer-like electric tooth brush (minus the brush tip) and I felt absolutely nothing…no stick, not anything. I felt very relaxed throughout the procedure.  

This is where, in my humble opinion, and together with my graduate degree in pharmacy, may leave room for a clinical study to determine the use of oral or even intravenous sedation in general dentistry. The question is whether to circumvent the pain associated with what some dentists refer to as “pumping”. Is there need for added pharmacological interventions ( use of muscle relaxants) when a slower delivery ( 60 seconds) would have proven just as effective and with reduced cost to the office?  The term “ Infants practicing on mom’s high heels’ is probably not inappropriate here.  

To suggest a case for advocating informed consent for the use of local anesthetics after 60 years of successful clinical use in dentistry appears less substantive phenomena to identify such rare sequellae such as temporary amaurosis, paresthesia and even death which would seem to be classified as operator error rather than of a biochemical origin.  All clinical evidence would seem to beg the question. “Does this track record reasonably qualify to put local anesthetics (amides) under curfew or to “throw them under the bus?”

There is without doubt in general dentistry, a need to address the needle phobic patient, however a sudden move to give patients a “high” may increase patient traffic  prone to chemical addictiveness as the word get around, but with consequences not every dentist is willing to spend time, effort, legal and peer review in their selective associations. 

Anesthetics and aesthetics — they even sound as though they work together. Informed consent seems rather like infants practicing on mom’s high heels.  However for general dentistry with limited experience of these  powerful opioid analgesic with a potency approximately 81 times that of morphine (wiki) may increase the traffic you may live to regret.

Comments to author.  mailto:localanesthetics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.Anestheticnews.com

Steven lost his taste for The Big Mac after a visit to his dentist. Dentist unable to explain: Could this be Dr. Watson’s first case of unexplained paresthesia? I was entering my sophomore year of engineering. This transition year would be taking me from broad-based general education to a more highly-focused mechanical engineering course through advanced studies in mathematics, science and systems. By all measurements, I was well positioned with my peers and my grades were above average. My freshman year was now over and I was literally pacing myself for the complexity of projects which eventually would see my skills put into practice. At this stage in my studies, I was like a sponge in the ocean soaking up all and every lecture I attended. Being pulled and pushed with every movement of the tide around me. No clear route was calculated on my internal GPS; however there was a steady wind which seemed to be pushing me on a definite course. Or so it appeared to me.

It was difficult to conceal my identity; I was from a small Midwestern town and attended a private high school with my siblings where we enjoyed a comfortable life as children of parents who were both professionals. My mother was a restorative hygienist and my dad, Dr. Watson, owned a well established dental practice.

I was now off campus and was fortunate to share a modest third story attic-like apartment with Steven, a student who was also in engineering, one year ahead of me. Our apartment was no more than 500 sq.ft. but comfortable and spotlessly clean, with a clear view across town where one could see the familiar Golden arches and where many a university student caught up on notes, while enjoying the special burger of the day. Steven was no exception. He loved to eat at the MacDonald’s; He was hooked on their Big Mac and ate there at least four or five tines a week. Our apartment consisted of a sitting area, a kitchen, a washroom and one bedroom with two single beds. I was beginning to feel more in charge of my life and free to come and go as I pleased. My room mate was friendly but somewhat quiet and deep within his thoughts, or so it appeared to me.

Our schedules were quite different, and we did not have a lot of time together other than the occasional small talk while having a coffee. We were not big on booze but enjoyed the odd beer. He had a part time job at a small computer repair store and would be home usually by midnight. The tempo and the anonymity of the North East were very fascinating and everyday I could feel maturity seeping into every move I made. I was at ease with myself and happy, especially when I heard from my folks.

Although it was never overtly pushed on me, the atmosphere at home during high school was subtlety an expectation of going on to undergraduate school in the East. I was the oldest of my siblings and now that I can reflect, both my parents were lovingly using me as their flagship.  “If Jim sets the pace, the others will follow”. I was fortunate in that I did not have to work during my semesters away from home. My mother saw to that. There were to be no excuses for failing grades. I lacked for nothing. However in no way was I pretentious. In fact I was often seen and not heard. Deep within me I knew I was popular albeit, shy. I was no “Brad Pitt”, but confident was I, or so it appeared to me.

It was during our second semester of my sophomore year that I started to have some concern about my room mate. He suffered from bruxism, commonly known as grinding of the teeth, typically accompanied by the clenching of the jaw. It is an oral para functional activity which is common in many humans. Bruxism  (Wiki) is caused by the activation of reflex chewing activity; it is not a learned habit. Through osmosis, I had picked up many dental terminologies over the years from both of my parents. This condition (grinding) was not unknown to me; however the situation was causing me restless nights. I talked to my dad during one of our weekly “how are you” conversations and he suggested that Steven should see a local dentist, because of possibly damage to his teeth. It was not difficult to share my concern with Steven, because his girlfriend also thought he should see a dentist.

We (Steven, his girlfriend Veronica and I) had now become much closer. Steven opened up a bit more and at times could be quite comical. I was seeing the other side of him. We started to hang out on a more regular basis. Steven had appreciated my father’s professional advice and did in fact go to see a dentist associated to our engineering faculty. The diagnosis was confirmed. There was some small initial damage which had started to erode the enamel of his molars. The dentist was able to have a guard fitted in Steven’s mouth with which he could sleep comfortably at night. A follow-up appointment was scheduled in a couple of weeks to make sure the protective appliance was fitting comfortably. However the dentist noticed there was an old amalgam filling on his LR bi-cuspid which was overhung and was a floss shredder. The dentist advised Steven it should be replaced with a more modern white filling. Amalgams are for the most part now dated. The trend is to natural color composite fillings. This was good news for Steven because the silver amalgam was a nuisance and unsightly for a youngster. The date was set for the replacement filling and all would be well, or so it appeared to me.

Steven showed up for his 9:00 AM dental appointment which would have given him ample time to get back to class and by noon the anesthetic would have worn off giving him sufficient time to enjoy his big Mac. However things did not go as was planned. Steven still had a numb jaw and although he tried to disregard this persistent strange feeling, it was apparent that he had indeed lost all taste for his favorite Big Mac and fries.  On the third day Steven called his dentist to explain jokingly that he had lost all taste for any food and in particular, his craving for a Big Mac fix. The dentist reassured him that some people react that way to local anesthetics but the numbness and tingling sensation would soon disappear and normal full sensitivity would be back. Steven apprehensively took his word, but after day five, the condition had not improved and Steven was in a panic and wanted another opinion.

Without knowledge of the total situation, my father was privileged only to “hear-say” and cautioned me that it could be a case of paresthesia, which is a potentially serious pitfall for which dentists hope never to encounter during the life of their practice. My dad did not want to be involved for obvious reasons. I was now on the horns of a dilemma. After-all Steven was my trusted friend and room mate.

Unexplained paresthesia:

Steven was now withdrawn and depressed. He had lost weight and his essays were suffering. Veronica accompanied him to the guidance counselor and a decision was made that he should see a neurologist. Paresthesia was in fact the diagnosis. This condition was explained to Steven and the prognosis was good because he had a simply and uncomplicated infiltration of the anesthetic and was not exposed to a full nerve block. There were still unanswered questions. Why would this occur? There was no truma to any neres.

Steven did his research and discovered that around this time a new local anesthetic called Septocaine had been approved by FDA for dental use in the U.S. Unlike most other anesthetic solutions which have a concentration of 2%, this new one was a 4% concentration. In other words, theoretically and pharmacologically speaking, all things being equal, or as the scientists would say, in vitro, one could use half the volume of the 4% solution to achieve what the 2% was capable of. Each one of us can have slight anatomical variations in the oral cavity, hence different responces.

For some unknown reason, dentists are in the habit of referring to volume (cartridges) used rather than by mg/ml. (actual mg given).As it turned out, Steven awoke now in its tenth day, to discover the paresthesia had been miraculously reversed and full sensitivity had returned to his tongue and soft tissue around his lip. No point of mentioning where he headed after he discovered there were no more pins and needles. All therapeutic compounds are accompanied with an index. The lesson to be learnt is that the product monographs included in any medication by FDA and are intended to be read. The term Minimal Effective Dose is alive and well. Following these instructions may avoid expensive and time consuming litigation.

Comments to author.  mailto:localanesthtics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.AnestheticsNews.com

 http://tinyurl.com/2bsqsz

References: Haas DA, Lennon D   J Can Dent Assoc. 1995  

Do you consider yourself as having fear for the dental needle? Or that you do not feel completely frozen? Most situations with which dentists are confronted today are a test of their artistic skills. The frequency with which they use all or some of these, especially  injectable approaches makes a big difference in the comfort level of the patient during and after a dental procedure. There are approximately twelve basic techniques to administer local anesthesia to the upper (maxilla) and about half that for the lower (mandible).  The more frequently each is used, the more proficient one becomes at them all. If one fails it is suggested not to modify it, but rather to move on to one of the other techniques.  

The important explanation is applicable to both patient and dentist.  There are two techniques…the Gow gates and the Akinosi which work with people like you. You should ask for one of them, since they almost never fail. If the dentist is not willing, you maybe advised to seek another opinion. Remember we are living in a world of “moi”. You should not have to undergo unnecessary pain.  Clinical situations in dentistry are to some extent, moving more in line with medical treatment, whereby the clinician is expecting some input and cooperation from the patient so that it becomes a team effort. Gone are the days where clinicians were looked upon as mystical healers. Medical doctors and dentists need that important input from patients because healing is hastened and painless when the patient understands and is actively involved.  

I encourage you to read on. It will be presented in a pleasing manner which gives you a better insight into one’s oral anatomy. The holistic approach today is that patients do better when they are involved with the whole body. This trend has been growing for many years on the medical side; however, that desire to know, has been slow on the oral health side. 

New diagnostic equipment capable of detecting certain forms of oral cancer at specific developments is starting to make a difference with the public at large.    Again it has been women who have picket up the gauntlet and are the ones most likely to ask questions. This may be more out of absolute clinical necessity, rather than by the nature of the beast. As an example women are more prone to develop grinding of the teeth and TMJ problems. 

Bruxism or grinding can be a serious problem.  When we chew our food, we can deliver a force of over 150 pounds per square inch (psi) to our teeth. But when we grind our teeth at night, there’s no food to absorb the impact, so the force on our teeth can be over 300 psi or more. That’s enough to cause permanent damage to your teeth, including cracked and chipped enamel, hairline fractures, and even wearing down of the teeth to the gum line. The enamel may become so worn that dentin inside of the tooth is exposed. If bruxism isn’t treated, it can lead to gum damage, loss of both natural teeth and restorations, and other more complicated jaw-related disorders such as the one I mentioned previously temporo-mandibular joint disorders). Over time, your teeth may become sensitive due to exposed dentin, and your jaws may even move out of proper balance. Grinding your teeth can also cause a wide variety of other symptoms including soreness and fatigue in your jaw and facial muscles, including ear and head aches. The corrective measures for bruxism involves fitted mouth guards and specific training on how to relax those muscles involved. Students attending high school and post secondary schools are very prone due to stress of meeting time lines etc.  Fortunately, these stretching exercising together with the hardware do work. As youngsters develop and life styles change, bruxism does decrease and hopefully disappears.

Whether it is true to say TMJ is seen more frequently in females than males is often questioned. The National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH) indicate that over 10 million people in the
United States suffer from TMJ problems at any given time. Both men and women experience TMJ problems; however, 90 percent of those seeking treatment are women in their childbearing years. Recent research indicates that more women seek medical care for a TMJ problem than men, and women are more likely than men to report ongoing pain. Physiological differences in pain signal processing may explain why more women suffer from TMJ conditions than men.

 In baboon studies, estrogen receptors were found in the temporomandibular joints of the female baboons, none were found in the males.Recent research has focused attention on the relationship between sex hormones and pain. A study conducted by Dr. Linda LeResche,
University of
Washington in
Seattle, demonstrated that women on hormone replacement therapy were 77% more likely to seek treatment for jaw pain than those not undergoing such treatment. Also, women on oral contraceptive therapy were 19% more likely to seek treatment. Evidence is emerging in support of a biological explanation for why there are more women suffering from TMJ pain.

It maybe that the diseases which affect the TM Joints are no different, really, than the diseases which affect other joints in the human anatomy. Rheumatoid, and Osteoarthritis; Inflammation of the Joint capsule; inflammation of the Synovial fluid, torn Ligaments, perforation, or tears in the rotator cuff. Internal derangement of the Condyle Head which is the knob-like projection that can be felt when one’s bottom jaw is extended to the fullest. Incidentally that is the approximate area that your dentist may direct the needle for those patients who complain that they are difficult to freeze.

 As a pharmacist I want to focus on the mode of action of drugs. Local anesthetics are drugs and therefore we need to be as equally informed as a dentist about these solutions. We frequently get calls from dentists requesting information on possible incompatibilities and any number of possible problematic patients. While we can not diagnose or treat, we frequently may offer suggestions if called when dealing with pharmacology and especially pharmacodynamics of other combination of drugs being used concurrently. Our training has to be current especially with new drugs (either legal or illicit) entering our communities.  

Dentists have in treat all types of patients with medical disabilities and the tremendous task to accommodate these patients. Think of any normal dental visit. It is not on the same par as an appointment with our masseur therapist.             They see patients with tourettee syndrome, (Tics), grand mal seizures, spastic episodes and Down’s syndrome, just to name a few.  

To precisely place the anesthetic injection for a block requires the skill to avoid depositing the solution in a vessel, artery or a muscle. Any sudden movement could accidentally enter these areas. In my opening comments I mentioned there were well over a dozen techniques available and the more frequently they are used, gives that dentist an added advantage. 

I will reiterate, if one approach fails, then the alternative is not to modify it but rather change to one of the other techniques. There are a number of physiological and pharmacological reasons to change to another approach. The number one consideration is the sensitive pH with which one has to deal. Healthy tissue is at pH 7.4 and the anesthetic is at around 3.5. To deposit more solution will not only cause the tissue to expand and cause swelling, but will further increase acidity. It is not uncommon for some patents to have more branches of nerves than others. They all originate from one large valley. The trick is to get the main one before it branches off into many smaller ones. When you are going after a bee’s nest, you want to smoke out the “queen” then the colony of workers is disabled. 

There are other times when a kid is un-cooperative or has a disability and will not open their mouth wide enough. There is a very cool technique where the dentist can get a block even with clinched teeth.  Yet another technique resulted from the researchers of a European pharmaceutical company. I am especially proud of this drug since I was on a team which was successful in gaining acceptance for this anesthetic to get approval in Canada and the FDA in the
U.S. I have no financial or personal interest in this drug as is generically manufactured anyway. However because of its biochemical structure it can pass through bone, especially with children from the outer vestibule on to the lingual side. The beauty of such an anesthetic is that your dentist can completely freeze a kid without freezing the tongue. Recovery to sensitivity is rapid depending on the volume deposited. The more you give the longer it lasts. However as little as half a cartridge can fully freeze a patient. The article was published in JCDA under the title of Mandibular infiltration by Drs. Dudkiewicz, Schwartz and Laliberte. (Dept. of pedodontics,

McGill
University). 

The techniques of such administration are part of my webinar meetings or full live lecturers.  

Comments are welcomed to author. mailto:localanesthetics@yahoo.ca   M.Sc. PharmD. CCPE  WWW.AnestheticsNews.com

I was advised not to go into law because members of that profession were 3.6 times more likely to be depressed, than members of other professions and it’s not just because their jobs were more stressful. Job stress has little effect on happiness unless it is accompanied by a lack of control. For most professionals, such as dentistry, stress is rated at the high end of the scale. Apparently stress is evident only when results are difficult to reproduce. Dentists have to work with variables which are of an anatomical nature, hence the predictable or lack of it, puts them already at a disadvantage. This article may explain why dentists are stressed. They are caught between a rock and a hard place. On the one hand they are dealing with patients who hate the shrillness of the piercing sound of a drill or burr and on the other, the lack of scientific longitudinal studies dealing with biology vs technology. Ironically, replacing the drill, poses other biology problems which are yet to be evaluated over time. 

Lasers in some ways resemble the compound Vitamin E. In spite of the almost mystical image it has with the public, it remains one of these agents that some medical gurus have unanswered questions. The population at large says Vitamin E is good for everything but removing the grease from the kitchen sink. While the doctors are saying, “show me the clinical evidence”. When lasers were introduced for use in dental procedures it brought with it many attributes which dentists were screaming to have and were willing to pay the substantial price tag. Dentist felt if they could reduce or replace the use of drills, burs and maybe the shot, then dentistry would be perceived as less painful and improve traffic over and above acute procedures or emergency drop-ins.

This is a good time to revisit laser analgesia and anesthesia. Women love to tell the joke about men being lost, yet failing to stop and ask for directions. They would sooner drive around in circles. Dentists also have the perception that they are doing well at being pain free. For us lay people, according to dental text books on anesthesia, there has always been those files marked “difficult to freeze”. If your dentist is within that 15% range, then to him/her that is considered zero or perfection. However would you purchase a parachute or fire extinguisher with a label that says 15 % failure rate?  Let me make it perfectly clear, it is not a bad batch of anesthetic. If it were, then almost the entire continent would have the same problem.

Dentists are trained to diagnose and treat. If the diagnosis is accurate and the treatment completed then the job is done - fait accompli. Right? Let’s be honest, if you had company over for dinner and you knew the roast was overdone or something was just not quite right, would anyone be that discourteous to say, “by the way the roast was lousy”. Patients are mostly kind and will never tell you the truth. However unless you have not been in touch with the clinical side, most people hurt at the very thought of a visit to the dentist. For me, there is a disconnect here somewhere. Your own blogs admit it. This is not a gang up.  

The reality is that above and beyond that accepted 15% failure, we are aware of the times when there is a need to reinject or reach for that painful PDL. Yet other times when the patient is “numb” except on distal lingual line of a molar. How can someone be numb and still have residual sensation? The question is rhetorical, of course, but as dentists you are aware of accessory innervations and are supposed to know how to capture all nerves. If you translated that into English, a person could be half pregnant. I am serious. One is either frozen or not. If 15 % is being accepted, when do we see the benefits of higher post graduate education, more modern university facilities and yes, the tremendous work that researchers and pharmaceutical companies have been doing since 1947 when Astra introduced the first dental cartridge with Xylocaine? We are at the same 15 % failure rate as we were then. I am wiling to be proven wrong.

Yes, you have moved on to lasers, apex locators monitors and a myriad of new composites, but is the pain and discomfort still there? Yes, implants, Invisalign and TMJ’s are all up. Lab work has taken on new dimensions, but is the pain and discomfort still there? Forgive me for rhetorical questions. One dentist said to me about laser, I am all for this technology. I have 5 years clinically behind me with the laser and I have successfully removed large alloys, composites and done crown preps, however in a low whisper confessed that he wonders whether laser anesthesia/analgesia really worked. Here is a balanced one from the other side. The patient had a fracture (N0. 11) which was an abutment to a bridge. The nerve was exposed and vital she had a note from her medic to avoid amides. The procedure involved removing the nerve which would not have been possible before laser technology and the RCT was completed successfully.

It is essential for any laser used in dentistry as an alternative to a drill be concerned about biology. What about thermal damage which a laser can cause due to the heat that is generated by the ablation of these materials. The ablation efficiency of the Er:YAG laser (?=2.94) on dental materials and one must allow for timely removal of amalgam and composite dental restorations. While it would appear that I am not cutting much slack to dentists who are working through the difficult transition, I am really on your side and wish to present to the public a better image than what exists today. From a distance what I see is a ‘first on the block mentality’. This attitude is directed at fellow dentists down the hall as well as to patients in general. Unfortunately the soldiers are not all instep. There is a disconnect. When expectations are set and results of the climax turn into a whopping anti climax, you have one hell of a task to regain that spot.

Here you are all decked out with the bells whistles and flashing colored lights in each operatory and you are wearing the amber eye protectors and the atmosphere looks impeccable, yet when the local is delivered and the expectation is that the procedure will start now, there is the wait while the dentist is off to another patient or to the hygienist. When they eventually return, that is the anti climax. After 15 minutes and I am jumping each time a gloved finger or probe enters my mouth. This never happened in dental school. You gave the local and right away your colleague was frozen. Now it is reasonable for the dentist to have to move from room to room, but the reason given is bogus. When given correctly, anesthetics work within 30 seconds at the first time. Show me in any text book where 25 seconds is the recommended delivery time. They all say 1ml/min. There is the problem.   

The term to “marinate” is not usually used by dentists, but we in pharmacy are familiar with the terminology. It basically means that the dentist may start injecting at multiple locations, with a hope that luck may be on his/her side and the patient will be frozen. My advice, speaking as a pharmacist and having the knowledge of how most drugs work, is that these multiple shots are warnings of trouble ahead. The flashing yellow is on and it may be telling you that the first injection did not do the job. The second and third (all the same drug, just by a different manufacturer’s name) will magically perform a trick from the turtle to the rabbit. (Sorry folk! this is an inside joke) your dentist may want to explain.

The dentist could sit with for an hour and explain in a similar way the salesman gave a demo at the trade show. However, you the patient are not interested with precision or smear layers. All you want is to feel nothing. To put it bluntly, you want to be fully frozen throughout the procedure. As a comparison, think of a knee implant under conscious sedation. The patient hears the saw and is aware, but there is no pain.

The biology of laser usage is still not known. It is an attempt to spare the patient the thought of a burr, drill and vibration. However, when we are dealing with living body parts, biology of structure, function, growth, origin, evolution and distribution must be factored in with longitudinal specific clinical studies. There are some prominent opinion leaders in perio who have refused to continue to lecture on closed flap crown lengthening. An area of concern is laser plume virus survival and thermal damage. Dental laser technology is here to stay because there are times when the alternative would have been general anesthesia because of severe anaphylactic shock if a local were used. However I fore see a revisit to closed technique because of the risk of bone necrosis.

A recent published article in the Journal of Periodontology, conducted at the University of Missouri, Kansas. Mullins, S.L., et al. - The purpose of this pilot study was to evaluate, by scanning electron microscopy (SEM), the surface effects of 3-CO2 laser treatment on the root surfaces and soft tissues and to investigate the effects of 3-CO2 laser on periodontal pathogenic bacteria compared to negative controls…A one-time use of the 3-CO2 laser in periodontal pockets did not sterilize or substantially reduce subgingival bacterial populations compared to negative controls.

In this age of better skills, more accurate and definitive diagnostic equipment and excellent patient compliance, there is obvious something missing when we hear the comment . . . “hang on there, we are just about finished.” Life styles have changed. That is one of my lecture topics. I hope you are not too deep in the forest to see the trees.

Comments to author. mailto:localanesthetics@yahoo.ca    M.Sc. PharmD. CCPE  

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Dentistry in transition! At face value this is a rather positive impact statement, given the general opinion held by the populace at large. However one must admit there are certain phrases, which our thought processes will not allow our brains to compute. It is like the parent being ambivalent about their kid’s promotion to a higher grade, yet being well aware Johnny’s skills are realistically one or two grades behind. There is the standard form letter, which accompanies this report card. ”It would be psychologically damaging to the kid if we had a ten year old sitting with eight year olds.” That is a fact of life, of which there is little we can do outside of cry victim.  

I accept that. However the term profound anesthesia is a dental term, referred to in any edition of Dr. Malamed’s handbook on local anesthesia or any other similar textbook. It is as explicit as the term pregnant. One is either pregnant or not.  My question obviously then is, why do we hear the explanation, “were it not for the dream team, O.J. would not be playing golf today”. There is an assumption that being completely numb, is like picking a lotto ticket or a good lawyer. To put it bluntly, a hypothesis consists either of a suggested explanation for a phenomenon or of a reasoned proposal suggesting a possible correlation between multiple phenomena (Wiki). 

For a dentist to truly eliminate residual sensation or even the slightest evidence of pain to the patient requires a pharmacological intervention which is achieved by reversing the polarity charges across the nerve sheath and by so doing, will block sodium transport. In a nutshell that is how the dentist freezes you. There is no magic; smoke, mirrors or even cartridge warmers. In fact, nothing other than the skill and the years of training and understanding certain biochemical interactions and of course the anatomy of one’s mouth. Some dentists can also arrive at the end result, (namely your comfort), by using other techniques to block sodium transport in either one specific area or to one or all quadrants of the mouth. This can be achieved at one sitting.  

For those patients who still suffer through a dental appointment, you should seek out one of the many thousand of dentists who have mastered that technique. Remember you are either pregnant or not. The same rule applies for being frozen. Now to be fare, the patient can be confused and equate pain with pressure. Pain is felt along the nerve, it is persistent and very recognizable. On the other hand pressure is transient. Its can quickly disappear as it appeared. Pressure will not follow you home and the slight soreness will disappear even without medication in most cases. However, one must accept that we are dealing with variables. Anatomical variables compounded by the ever presence of Murphy’s Law can and does throw a spanner in the works. There will be those challenging days in any dental operatory. 

Ah! Think of the beauty and the protection for our teeth. Never has our world been so versatile as it is today. Times were when people conversed, it was common practice to place their fingers to cover their teeth or an attempt to conceal mal odor. Dentists have collectively deleted that era with their skills of art knowledge of gum disease. Especially at this time of the year where folks get together to celebrate, it is the confident radiance of wide smiles across the room as though they were saying, “look at the work my dentist did”. These smiles are as fashionable today as it is to tote around a 450 ml of Evian water. Let us not change that trend. The patient must be frozen. Not only soft tissue. 

However what continues to be unexplainable is the ever-increasing incidences of trauma resulting from achieving profound anesthesia. This is the conflict that one has to deal with when they hear the term “Dentistry in transition”. As one popular dentist explained this scenario to me, “It is this expanding team based reconstructive approach which mandates the use of convergence technologies in order to ensure timely and accurate continuing education. His final tip was to concentrate on moving records, not patients.”   

If this terminology is aimed at a trend towards cosmetic dentistry and away from the traditional drill and fill, it does not negate the increasing failure to achieve profound anesthesia and the accompanying problems of physical trauma. It should never be a question of how much pain is the patient willing to endure to finally toss the bed-side glass with their dentures to have a permanent set of implants. Pain should never be a bargaining factor. Of course there is a price to be paid, but the patient has already made that decision, whether it be Whitening, Bonding, Porcelain veneers or crowns. The objective should be the same as it was in dental school when you delivered your first ever injection to a fellow student and he/she reciprocated. You made sure you did not cause pain to your buddy and that you did indeed freeze your fellow student. If this situation has changed and failures seem to be on the increase, what has changed?  Is it the converging technologies and the accompanying stress of entering un-chartered waters? Why is this? The ability to achieve anesthesia should not be relevant. 

At any addictive or compulsive behavior center, your first bit of advice one receives is that you are on your way to recovery simply by admitting there is a problem. If this problem is on the rise it may be completely out of your hands, however it still has an impact on your daily activity and unfortunately in dentistry, the denial to communicate will continue to fray that weak spot on the line and one day it will snap. 

Andy Warhol is credited with the following: “An artist is somebody who produces things that people don’t need to have”. Dentists are frequently referred as being artist. Earlier I referred to the beautiful smiles by which we are surrounded today. However there is no need to have to go through hell to acquire this. The action potential of local anesthetics and other agents are the domain of bio-chemistry and pharmacodynamics. While respecting the inevitable convergence of technologies in dental offices in this dynamic profession and life styles, Be kind, take your time. “It sure was good while it lasted”. Now it’s time to pay the piper. It’s all over but the crying. Too late to do anything but moan about it now.” (Chris Kristofferson.)

Contact us at localanesthetics@yahoo.ca  M.Sc. PharmD. CCPE   Please visit WWW.AnestheticsNews.com  Tel. 905-597-5688   

Steven lost his taste for The Big Mac after a visit to his dentist. Dentist unable to explain: Could this be Dr. Watson’s first case of unexplained paresthesia?

 I was entering my sophomore year of engineering. This transition year would be taking me from broad-based general education to a more highly-focused mechanical engineering course through advanced studies in mathematics, science and systems. By all measurements, I was well positioned with my peers and my grades were above average. My freshman year was now over and I was literally pacing myself for the complexity of projects which eventually would see my skills put into practice. At this stage in my studies, I was like a sponge in the ocean soaking up all and every lecture I attended. Being pulled and pushed with every movement of the tide around me. No clear route was calculated on my internal GPS; however there was a steady wind which seemed to be pushing me on a definite course. Or so it appeared to me.

It was difficult to conceal my identity; I was from a small Midwestern town and attended a private high school with my siblings where we enjoyed a comfortable life as children of parents who were both professionals. My mother was a restorative hygienist and my dad, Dr. Watson, owned a well established dental practice.

I was now off campus and was fortunate to share a modest third story attic-like apartment with Steven, a student who was also in engineering, one year ahead of me. Our apartment was no more than 500 sq.ft. but comfortable and spotlessly clean, with a clear view across town where one could see the familiar Golden arches and where many a university student caught up on notes, while enjoying the special burger of the day. Steven was no exception. He loved to eat at the MacDonald’s; He was hooked on their Big Mac and ate there at least four or five tines a week. Our apartment consisted of a sitting area, a kitchen, a washroom and one bedroom with two single beds. I was beginning to feel more in charge of my life and free to come and go as I pleased. My room mate was friendly but somewhat quiet and deep within his thoughts, or so it appeared to me.

Our schedules were quite different, and we did not have a lot of time together other than the occasional small talk while having a coffee. We were not big on booze but enjoyed the odd beer. He had a part time job at a small computer repair store and would be home usually by midnight. The tempo and the anonymity of the North East were very fascinating and everyday I could feel maturity seeping into every move I made. I was at ease with myself and happy, especially when I heard from my folks.

Although it was never overtly pushed on me, the atmosphere at home during high school was subtlety an expectation of going on to undergraduate school in the East. I was the oldest of my siblings and now that I can reflect, both my parents were lovingly using me as their flagship.  “If Jim sets the pace, the others will follow”. I was fortunate in that I did not have to work during my semesters away from home. My mother saw to that. There were to be no excuses for failing grades. I lacked for nothing. However in no way was I pretentious. In fact I was often seen and not heard. Deep within me I knew I was popular albeit, shy. I was no “Brad Pitt”, but confident was I, or so it appeared to me.

It was during our second semester of my sophomore year that I started to have some concern about my room mate. He suffered from bruxism, commonly known as grinding of the teeth, typically accompanied by the clenching of the jaw. It is an oral para functional activity which is common in many humans. Bruxism  (Wiki) is caused by the activation of reflex chewing activity; it is not a learned habit. Through osmosis, I had picked up many dental terminologies over the years from both of my parents. This condition (grinding) was not unknown to me; however the situation was causing me restless nights. I talked to my dad during one of our weekly “how are you” conversations and he suggested that Steven should see a local dentist, because of possibly damage to his teeth. It was not difficult to share my concern with Steven, because his girlfriend also thought he should see a dentist.

We (Steven, his girlfriend Veronica and I) had now become much closer. Steven opened up a bit more and at times could be quite comical. I was seeing the other side of him. We started to hang out on a more regular basis. Steven had appreciated my father’s professional advice and did in fact go to see a dentist associated to our engineering faculty. The diagnosis was confirmed. There was some small initial damage which had started to erode the enamel of his molars. The dentist was able to have a guard fitted in Steven’s mouth with which he could sleep comfortably at night. A follow-up appointment was scheduled in a couple of weeks to make sure the protective appliance was fitting comfortably. However the dentist noticed there was an old amalgam filling on his LR bi-cuspid which was overhung and was a floss shredder. The dentist advised Steven it should be replaced with a more modern white filling. Amalgams are for the most part now dated. The trend is to natural color composite fillings. This was good news for Steven because the silver amalgam was a nuisance and unsightly for a youngster. The date was set for the replacement filling and all would be well, or so it appeared to me.

Steven showed up for his 9:00 AM dental appointment which would have given him ample time to get back to class and by noon the anesthetic would have worn off giving him sufficient time to enjoy his big Mac. However things did not go as was planned. Steven still had a numb jaw and although he tried to disregard this persistent strange feeling, it was apparent that he had indeed lost all taste for his favorite Big Mac and fries.  On the third day Steven called his dentist to explain jokingly that he had lost all taste for any food and in particular, his craving for a Big Mac fix. The dentist reassured him that some people react that way to local anesthetics but the numbness and tingling sensation would soon disappear and normal full sensitivity would be back. Steven apprehensively took his word, but after day five, the condition had not improved and Steven was in a panic and wanted another opinion.

Without knowledge of the total situation, my father was privileged only to “hear-say” and cautioned me that it could be a case of paresthesia, which is a potentially serious pitfall for which dentists hope never to encounter during the life of their practice. My dad did not want to be involved for obvious reasons. I was now on the horns of a dilemma. After-all Steven was my trusted friend and room mate.

Unexplained paresthesia:

Steven was now withdrawn and depressed. He had lost weight and his essays were suffering. Veronica accompanied him to the guidance counselor and a decision was made that he should see a neurologist. Paresthesia was in fact the diagnosis. This condition was explained to Steven and the prognosis was good because he had a simply and uncomplicated infiltration of the anesthetic and was not exposed to a full nerve block. There were still unanswered questions. Why would this occur? There was no truma to any neres.

Steven did his research and discovered that around this time a new local anesthetic called Septocaine had been approved by FDA for dental use in the U.S. Unlike most other anesthetic solutions which have a concentration of 2%, this new one was a 4% concentration. In other words, theoretically and pharmacologically speaking, all things being equal, or as the scientists would say, in vitro, one could use half the volume of the 4% solution to achieve what the 2% was capable of. Each one of us can have slight anatomical variations in the oral cavity, hence different responces.

For some unknown reason, dentists are in the habit of referring to volume (cartridges) used rather than by mg/ml. (actual mg given).As it turned out, Steven awoke now in its tenth day, to discover the paresthesia had been miraculously reversed and full sensitivity had returned to his tongue and soft tissue around his lip. No point of mentioning where he headed after he discovered there were no more pins and needles. All therapeutic compounds are accompanied with an index. The lesson to be learnt is that the product monographs included in any medication by FDA and are intended to be read. The term Minimal Effective Dose is alive and well. Following these instructions may avoid expensive and time consuming litigation.

Comments to author.  mailto:localanesthtics@yahoo.ca    M.Sc. PharmD. CCPE   WWW.AnestheticsNews.com

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References: Haas DA, Lennon D   J Can Dent Assoc. 1995  

Questions re dosage of local anesthetics is in our top 10 list. We therefore think it is appropriate to clear up what is meant by this important subject…relative and absolute maximum dose.  For lighter weight individuals, the relative maximum dose can be calculated by mg/kg. This can be less than the “absolute” maximum dose.  However for heavier weight individuals, the volume, i.e. mg/kg of the local anesthetic cannot exceed the absolute maximum for that particular local anesthetic. We at www.anestheticsnews.com  go into great detail in our lecturers especially when articaine is used in children . As usual your comments are valued. You may respond directly or mail us at localanesthetics@yahoo.ca  (M.Sc. Phm. CCPE) 

May be we need to get back to basics. In Pharmacology 101, we’ve heard the terms, bioavailability, antagonistic, synergistic, protein binding half life etc, etc on a daily basis. The response of any drug to produce its desired effects is directly related the manufacturer’s product monograph, having been cleared by regulatory agencies such as FDA.  Two common examples to which we can relate are the administration of nitroglycerin for angina and lorazepam (Ativan) as a mild sedative. When administered sublingually, the desired response is met. In fact, if swallowed, the affect may be compromised at best or at worst, not efficacious.Should local anesthetics be exempt from the manufacturer’s product monograph? They clearly state that administration should be at the rate of 1ml/min. Ref.  Dr. S. Malamed Fourth Edition of Local Anesthesia. Further more, to refer to “cartridges administered” rather than mg/kg, adds insult to injury, since there is a proximally 35mg in one cartridge of lidocaine and 70 mg in one cartridge of articaine Hcl. Thoughts to ponder. 

We  at   www.anestheticsnews.com    Welcome any direct input or you   may   e-mail us at localanesthetics@yahoo.ca  

The Oraqix® Patient Portal introduces dental patients to the first FDA approved subgingival anesthetic, Oraqix® and provides an overview of oral care and gum disease. Oraqix® (lidocaine and prilocaine periodontal gel) 2.5%/2.5% is a novel liquid oil non-injectable anesthetic that allows patients to experience needle-free scaling and/or root planing procedures. Oraqix® does not prevent gum disease or periodontitis.

Zingo is a ready-to-use, single-use topical. This is the latest FDA  approved needle-free system that delivers sterile lidocaine powder into the sulcus or epidermis of the skin and provide topical, analgesia in one to three minutes after administration. This potent rapid onset action, may be especially useful in pediatric procedures, which means the product can be incorporated into a procedure allowing uninterrupted care.

Traditional ester type gels (Benzocaine), which are well known to be allergenic, may be following a similar demise as did the ester type locals injectables. Please add your comments directly or e-mail at localanesthetics@yahoo.ca