The Dentist's Network #91

Chris J. Lampert, DMD
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Small Hand Files

Endodontics has seen many technological advances in the last fifteen years, such as rotary instrumentation, ultrasonics, MTA root repair material, apex locators, and the surgical operating microscope, to name a few. However, small hand files are still an important part of successful endodontic treatment. The ability to negotiate and clean the canal to its terminus is the most important objective in endodontic treatment. Selecting the proper small hand file is critical to achieving this objective.

Before nickel titanium rotary files are used to shape the canal, small hand files are first used to negotiate the canal to patency, determine working length with an apex locator, and create a glide path for rotary files to follow. Hand files are divided into two groups, small sizes and large sizes. Small sizes include .06, .08, .10 and .15, and large sizes include size .20 and above. The desired properties of small hand files are very different than larger hand files. Small hand files should be stiff, twisted (not ground), and made of stainless steel. Larger hand files (sizes .20 and above) should be flexible, ground, and made of nickel titanium. The use of stainless steel files greater than size .15 in the apical region will lead to canal transportation and ledge formation and therefore should be avoided.

Stiffness
Stiffness is the most important property for small hand files and because of this fact, manufacturers now offer “extra stiff” small hand files usually referred to as C-files. Stiffness allows the file to withstand a longitudinal loading force as the file is worked towards the canal terminus. Highly flexible small files buckle and bend when worked in the apical direction. Stiffness of small hand files is dictated by three main factors: manufacturing process, cross-sectional shape, and material.

Manufacturing Process
Endodontic files are manufactured by either twisting a pyramidal shaped wire to create the helical spiraled fluting or by grinding the spiraled flute pattern into the files working length. Twisted files produce a much stiffer end product than that of grinding. This is why small hand files should be manufactured by the twisting process and larger files are manufactured by the grinding process.

Cross Sectional Shape
Stiffness is also affected by the cross-sectional shape of the file. A square cross-sectional shape has a larger core mass and produces a stiffer file than a triangular shape. This is the reason file sizes .06, .08, .10, and .15 have a square cross section and sizes .20 and above have a triangular cross section.

Stainless Steel vs. Nickel-Titanium
The third factor influencing stiffness is the material used to manufacture the file. Stainless steel is preferred over nickel titanium for small files because of its increased stiffness and its ability to retain a deliberately placed curve.

Method of Use
For most canals, I begin with a size 8 file connected to an apex locator. A size 8 file has a tip diameter of .08mm and a 2% taper (.02 taper). Starting with a larger file, especially in vital cases, has a greater chance of compacting pulp in the apex and preventing patency. It is also very important that the initial files taken to the apex are coated with a canal lubricant such as RC Prep. Lubricants also prevent pulp compaction in the apex, which is the leading cause of canal blockage. After obtaining the canal length with an 8 file connected to an apex locator and achieving patency (you must get a patency reading on the display), I go to a 10 file. Similar to the 8 file, the 10 file is coated with lubricant and used with an apex locator to achieve a patency reading. Using a second file with an apex locator confirms the working length established with the 8 file. Then a size 15 file is negotiated to full working length, followed by a size 10 file taken .5 mm long. Yes, long, meaning through the apical foramen. This is the “Patency File” and it is used throughout the remainder of the procedure to keep the foramen patent and clear of debris. Now that working length, patency, and a glide path have been established, rotary instrumentation can take place in a safe and efficient manner.

On the Horizon
Currently, there are manufacturers developing small negotiation files with improved apex locator connection assemblies for easier apex locator use. These files will provide more options for connecting an apex locator and improve tactile feedback when negotiating a canal with the aid of an apex locator. It is expected that these instruments will be available within the next year.

In summary, all small hand files are not the same. Using the proper file greatly enhances a clinician’s ability to negotiate the apex and achieve patency. As an endodontist, I treat many calcified canals, most of which could not be negotiated without a stiff, stainless steel small hand file. In a time when microscopes, rotary files, apex locators, and digital radiography are getting all of the attention, don’t forget the importance of using the correct small hand files.

Chris J. Lampert, DMD maintains a fulltime Endodontic practice in Portland, Oregon, and is involved with research, testing, and development of new endodontic products. Dr. Lampert received his DMD from Oregon Health and Sciences University and his Endodontic post-graduate degree from Boston University.

Dr. Lampert can be reached at drlampert@thedentistsnetwork.net

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Dr. Ryan Swain
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Two Kinds of Cosmetic Dentists

I was eating lunch with some dentists a few years ago and a very interesting conversation took place. I've spent a lot of time thinking about that conversation because it raised some important concepts that I believe all dentists should consider. The conversation began when one of the dentists said: "When a patient asks me if they need cosmetic dentistry, I just tell them that it is totally up to them." Another dentist at the table jumped in and responded by saying: "It's your job to tell your patients about their cosmetic options and whether or not you think they could benefit from cosmetic dentistry."

The conversation continued and turned into a fiery exchange between these two colleagues. They had very different opinions about what a dentist's duty is in regard to cosmetic dentistry and cosmetic recommendations. I've thought about that conversation many times over the last few years and some important ideas have crystallized for me during that time. I've realized that there are essentially two types of dentists when it comes to cosmetic treatment recommendations:

Dentist #1 believes that his/her duty as a dental professional is to diagnose and treat disease and structural issues but does not believe that he/she can or should diagnose cosmetic discrepancies unless the patient inquires about them. Dentist #2 believes that his/her duty as a dental professional is to diagnose and treat disease, structural and cosmetic discrepancies because these are all important aspects of complete dental health. If you fall into the category of Dentist #1, this article is an attempt to shake you up a bit and perhaps even persuade you to become a Dentist #2. In other words, get with the program!

As dentists, we are teeth people. We know how much a person's smile affects their overall appearance. In fact, we spend most of our time during conversations staring at teeth and diagnosing all of the cosmetic discrepancies that we see. When we look through a magazine, we stare at the smiles on the page, when we walk through the mall, we consciously think about the models’ smiles on the banners - especially if there are cosmetic problems! We are the experts. We can identify the aspects of a smile that can and should be changed in order to drastically improve the symmetry and esthetic appeal. There is a tremendous amount of value in this expertise we have all developed during our years as clinicians. I believe that if we hide this expert ability away, only drawing from it when patients ask us for our opinion, we do a tremendous disservice to our patients and our practices. Health and beauty go hand in hand and we owe it to our patients to educate them about both aspects of their smiles.

This idea was conveyed to me in a very poignant way when I was fresh out of dental school. I was a new associate and had just started working in a dental practice. I was performing a hygiene exam on a man in his late forties and noticed that he had a stainless steel crown on #8. I had never seen an anterior stainless steel crown on an adult before. The crown was contoured properly, the margins were good but boy was it ugly! I asked the patient how long he had had the crown and he told me that it had been placed when he was about eight years old. I asked him "Do you have any interest in replacing that steel crown with a porcelain crown?" He asked a simple and concise question that I can still hear in my head to this day..."WHY?" I was dumbfounded. I didn't know what to say. I had all kinds of thoughts racing through my head but I was a good boy and resisted the urge to say something like "Because silver teeth are ugly!" or "Because you look like a cyborg!"

After further discussion with the patient, I realized that he honestly had never thought about the cosmetic appearance of the steel crown on #8. It had been in his mouth since he was eight years old and was fundamentally a part of him. He didn't question it. He simply didn't have the dental IQ or cosmetic awareness needed to recognize the impact that the crown had on his overall appearance. But, even as a new dentist with little experience, it wasn't hard for me to clearly see the cosmetic gravity of the situation (in other words, he had "metal mouth!”). I knew that the steel crown was a serious detriment to his appearance and was a social hindrance for him. I knew that the steel crown negatively affected the manner in which others perceived this gentleman. Since I cared about the well being of this man, I felt responsible for educating him. I spent some time with him over the next few months and explained to him the characteristics of a nice smile. I asked him to pay attention to other people's teeth during conversations and while watching TV.

After a few weeks, he called the office and set up an appointment. We removed the steel crown and replaced it with a nice porcelain restoration. The difference was amazing. When he returned to the office for his next hygiene appointment, I asked him how the crown was working for him. He shared some amazing stories about the great comments he had received. The patient thanked me profusely and then said something that has stuck with me. He said "If you hadn't told me that I should have that crown replaced, I probably would have lived with that darn silver tooth for the rest of my life!" This extreme case made me realize firmly that I had a duty to my patients to inform them about cosmetic discrepancies and corresponding treatment options. Their social health and well being could depend on it!

Since that time, I started a practice that focuses almost exclusively on Short Term Ortho (www.6MonthSmiles.com) and other cosmetic dental procedures. I realize now more than ever the dramatic improvement that cosmetic dentistry can provide for our patients. Improving the overall symmetry of a smile is paramount in creating a pleasing look. The stories of improved self esteem, self confidence and social status that my patients report continue to bolster my belief in the importance of the services I provide. So, if you're a dentist who feels that cosmetic dentistry should only be discussed when a patient brings up the topic, please consider a paradigm shift. Our patients depend on us for our expertise - ALL of our expertise. They want us to have their best interest in mind. If we turn a blind eye to the appearance of their smiles, we are doing a disservice. We can and should tactfully and respectfully educate our patients about their cosmetic discrepancies. I believe that a cosmetic exam should be a regular part of our comprehensive examinations and all offices should have a chief cosmetic complaint form as part of their new patient/recall paperwork.

People desire to look and feel their best and we can do a lot to help them achieve this. I encourage you to utilize all of the abilities you've acquired throughout the years to the benefit of your patients. We're not just tooth mechanics; we are highly trained clinicians and oral esthetic experts. Everyone benefits when we understand these roles and play them appropriately. If you’re not a Dentist #2, please join the club. It’s a good one!

Dr. Ryan Swain is a graduate of the University of Florida College of Dentistry. He practices in Rochester, NY and focuses on Short Term Ortho and other conservative cosmetic dental procedures. He is president and chief clinical instructor for Six Month Smiles. Dr. Swain is a pioneer in the field of Short Term Ortho and constantly on the forefront of GP orthodontics. He has trained dentists internationally and prides himself on de-mystifying orthodontics for GPs.

Dr. Swain can be reached at Drswain@thedentistsnetwork.net

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Louis Malcmacher
DDS MAGD
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Don't Cross-Contaminate Me

Since I began practicing dentistry, now almost 30 years ago, probably the area that has changed the most is the area of infection control in dentistry. Yes we have had many technological advances such as CADCAM and lasers but on a day-to-day, in the office nuts and bolts part of the practice, infection control has changed the way that we practice dentistry and may continue to do so.

I remember in dental school we never wore gloves, except for particularly bloody extractions and even that was unusual. I remember some instructors calling people who wanted to wear gloves during those kinds of extractions “sissies.” We would certainly wash our hands very well before each patient and in between patients and that was considered adequate infection control. Before I sound like I am from the dark ages, we did have autoclaves even back then but most everything in the operatory was wiped down with somewhat damp alcohol gauze. That was considered good enough.

Certainly, in this day and age, infection control has become much more serious and much more effective. Everything that goes into the patients’ mouth is autoclaved. Countertops and other areas that cannot be sterilized are disinfected with excellent products. We know that we cannot make the dental operatory a complete sterile environment, but we have certainly done a much better job controlling this as ever before.

With all of our infection control procedures, what is incredible is that sometimes we miss the very obvious. I would like to direct you to a study done at the University of North Carolina Chapel Hill School of Dentistry about bib clip chains. Yes, that is right, the little chains that you clip on the patients bibs can be a real source of cross-contamination and most dental offices have not even thought about or addressed this issue. Think about this scenario – a patient walks in, sits down in the dental chair, the assistant is bare-handed then takes the bib that is put on the end of the dental chair which has been used on the last six patients, she picks up this bib chain, fiddles with it to straighten it out because sometimes it gets knotted up, and then puts this around the patient’s neck. The dental assistant’s hand has now been cross-contaminated with saliva, pathogens, hair, blood, and lots of aerosol sprays that have been clinging to this bib chain. The patient is then laid back into the chair and as is very normal, the bib starts to slide off of one side so we fix it for the patient and many times the bib chain brushes against the patient’s face or even their lips or sometimes even into their mouths. You and I both know that bib chains are rarely disinfected and certainly never sterilized.

The bib chain culture studies carried out at the UNC School of Dentistry demonstrated that 1-in-5 bib chains harbored pseudomonas, E.Coli, and staphylococcus aureus. These colony-forming units were of sufficient quantity to be considered an actual source of cross contamination. Further, considering that the disease-causing bacteria found on bib chains have also been implicated in respiratory infections within the general public, patients with compromised immune systems and breathing disorders may be even at greater risk.

Certainly, we all know that blood borne viruses can live in operatory surfaces for up to one week, especially when these surfaces are not disinfected either the right way or certainly when they are not cleaned or sterilized at all. The Center for Disease Control and Prevention defines cross-contamination as the act of spreading bacteria and viruses from one surface to another. In short, the bib chain fits every definition of cross contamination, so it must be addressed in the dental office.

The reason it sounds like I am making a big deal of this is because it is. I have been around too long in dentistry to know that if we don’t start taking care of some of these major or minor concerns ourselves, then they become big expose articles in Reader’s Digest or on CNN Health Watch and the media can make it sound as if dentists are infecting millions of patients every single day with something that is actually very simple to take care of.

Here are your choices to avoid the risk of bib chain contamination. With each patient bib change you can:

Ultrasonically clean them, place in a pouch, and autoclave to completely sterilize the bib chain.
Rinse off any gross debris, immerse the bib chain in an EPA Registered disinfectant (for the time needed to properly disinfect), then remove, dry and store in a clean area.
Use a disposable bib holder such as Bib-Eze by DUX Dental www.duxdental.com . These are single use disposable bib holders made of soft elasticized fiber which will eliminate the cross-contamination and you will never have to clean a bib holder again. They are also priced very economically and come out to less than a disinfectant wipe.

These are simple solutions to ensure that we never have to worry about such a small item that could turn into the next “scandal” in dentistry.

Louis Malcmacher DDS MAGD is a practicing general dentist and an internationally known lecturer, author, and dental consultant known for his comprehensive and entertaining style. An evaluator for Clinicians Reports, Dr. Malcmacher is a consultant to the Council on Dental Practice of the ADA.

Interested in having Dr. Malcmacher speak to your dental society or study club? Click here. To reach Dr. Malcmacher, email him at DrMalcmacher@thedentistsnetwork.net or call 1.800.952.0521.

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