I Thought Root Canals Are Forever?

One of the most common statements I hear from patients experiencing dental pain related to teeth that have already had root canal therapy is “but I thought there’s no nerve and I won’t ever have a problem?“…

courtesy of "http://www.deardoctor.com/"

Unfortunately this is far from reality.  Typically, a root canal is done when the tooth’s nerve is so badly inflamed that it cannot heal itself.  This can happen from a bad cavity, chronic decay underneath an existing filling or crown, or from a tooth fracture. Since the nerve is beyond the point of repair, there is pain or infection, and it must be removed. The space that the nerve used to occupy is filled and sealed with a material called “gutta percha”, aka root canal.

The sealant, however, may not last forever. New decay can form and the bacteria causing the decay can travel the entire length of the root all the way to the tip and into the jawbone.  What happens next is cyst formation in the bone as your immune system attempts to cope with the bacterial infiltration.  When the cyst reaches a certain size, there is pain when you bite down.  Not tooth nerve pain, but jawbone pain!

Sometimes another attempt at root canal can be done to remedy this. It really depends on the circumstances and whether the adjacent teeth are impacted or whether the new decay is beyond repair. Other times the jawbone is so badly infected that the tooth cannot be saved and must be removed.  The general industry consensus is that the average lifespan of a root-canaled tooth is about 7 years before it needs attention.  That’s only an average, however.  I’ve seen root canals fail after 1 week, and I’ve seen decades of success.

Another unfortunate consequence of a root canal is the tooth is generally rendered more brittle and prone to fracture. If there is a post as part of the restoration, that also represents a weakness in the tooth structure.  Natural, intact teeth rarely fracture, but when we do see a fractured tooth it’s almost always one with a history of root canal therapy.

It would be nice if clinicians were a little bit more forthcoming about the longevity and realistic expectations of doing a root canal.  It’s still one of the best way to preserve an infected tooth.  Unfortunately like just about anything else, it’s not without real risks, and there’s a good chance it won’t last forever.

Deceptive Dentists

Raise your hands if you’ve seen any of these descriptions before: implantologist, dental implant specialist or cosmetic dentist…Guess what?  There is no such thing.  No such specialty as dental implants or implantology is recognized by the American Dental Association.  There are residency programs that teach dental implants, some of which take years to complete. Then there are weekend courses that offer a limited educational experience.  The levels of training for dental implants vary significantly from excellent to useless, leaving the consumer further unsure.  As for cosmetic dentists, all dentists are cosmetic – is there a non-cosmetic dentist?  Some may be better than others but sometimes it sounds as if it is a special title with special training involved, which is not accurate.

Another way that dentists confuse consumers is by making claims such as “we offer a full range of x services” when they are not.  These statements may put dentists in danger of offering a standard of care that is not justifiable.  Offering free exams is another gray area, as it unfairly puts pressure on a competing practice.  The FTC is the regulatory body involved but many of the guidelines are vague.

Grade 5 Titanium for Dental Implants???

For years Grade 4 commercially pure titanium has been the material of choice for dental implants.  There is plenty of long term data demonstrating safety and success.

More recently some manufacturers have been switching over to Grade 5 titanium.  Titanium Grade 5 is alloyed with 6% Aluminum and 4% Vanadium and is commonly known as Ti 6Al-4V.  For dentistry, there is another version called “ELI”, extra low interstitials, which further reduces surface impurities.  Grade 5 titanium is said to be stronger than Grade 4.  However there is evidence that Vanadium is released into the host tissues and can be cytotoxic.

A recent literature review concluded that there is not enough evidence indicating superiority of one vs the other, noting specifically that good clinical comparison studies do not exist.

I have made inquiries to implant manufacturers asking for long term safety data in humans, and so far I have received nothing decisive.  Hmmm…

The Case for Erbium in Periodontics

There are many different wavelengths to choose from, depending on the clinical needs.  I want to begin by explaining why Erbium lasers seems to be ideally suited for comprehensive periodontal treatment.

We have all seen the chart showing the absorption coefficient of different wavelengths in water.


This is important for us to understand since water is a main component of dental tissues.  The CO2 laser is absorbed very well in water, but there is a tendency to see charring and thermal effects in soft tissue, as well as melting of hard tissues.  This does not make it very friendly for periodontal therapy where cementum and roots are involved, although a newer pulsed CO2 laser does improve on this problem.

Diode and Nd:YAG penetrate deep into tissue and may cause unseen thermal effects.  Currently, they seem to be positive as adjuncts in periodontal therapy, as long as laser energy applied to the roots is kept minimal and controlled.

Erbium lasers have an excellent ablative potential in soft tissues, do not penetrate deep, and do not show the same thermal damage as the other wavelengths.  They seem to be ideally suited for comprehensive soft tissue periodontal treatment, as well as calculus removal and root treatment.

There are 2 different Erbium lasers: Er:YAG and Er, Cr:YSGG.  Both have a very similar absorption spectrum.  There are few studies that compare their physical properties.  As one study shows, it is difficult to analyze different systems because of the different manufacturer parameters.

For all intents and purposes, and to facilitate a meaningful discussion, going forward we will assume that all Erbium laser studies are reasonably interchangeable.  Literature reviews will follow very soon.


LIT REVIEW: Yukna's Nd:YAG LANAP Article

Let’s take a closer look at this often cited article, and see how effective the LANAP procedure really is: Yukna, Carr and Evans.  Histologic Evaluation of an Nd:YAG Laser-Assisted New Attachment Procedure in Humans.  Int J Periodontics Restorative Dent 2007 27: 576-587.

Materials and Methods

First and foremost, only 6 pairs of teeth were analyzed in this study – hardly a big sample size.

While not necessarily a major issue, it is worth noting that all experimental teeth received “occlusal adjustment and were splinted to neighboring teeth with an extracoronal bond”.  Why do I bring this up?  This is part of the LANAP protocol, but I highly doubt it is even being done in private practice.

Additionally, all teeth received an unspecified  “triple antibiotic ointment” and a “light cured dressing”.  Again, definitely not routine measures taken in private practice, and undoubtedly they play some role in the treatment outcome.  However, since all teeth received this treatment, a comparison of control vs. experiment is fair.


Cementum mediated new attachment was evident on 4 lased teeth, but Yukna himself states that “similar periodontal healing in humans has been shown with other surgical techniques”.

How much new cementum was actually seen?  An average of 1.2mm.  Repeat, just 1.2mm.

By no means would I consider this a good result.  As Yukna clearly states in the beginning, “regeneration of the supporting tissues of the teeth is a primary goal of periodontal therapy”.  Numerous studies demonstrate superior results when regenerative materials, such as grafts, membranes, Emdogain or rhBMP are used.

How can any clinician justify lowering the bar for periodontal therapy?  How is this an advancement in patient care?

This study does clearly demonstrate “new attachment” and new cementum.  The fibrin clot in the lased pocket apparently acts as an effective barrier to epithelium advancement, thereby allowing periodontal healing to proceed favorably.  But it does not empower dentists to offer superior treatment to patients.

Closing Comments

One may ask, why not use regenerative products with a proven record, in combination with Nd:YAG therapy? Nd:YAG, being so efficient in hemorrhagic tissues, promotes a fibrin clot that prohibits the use of regenerative material simply because there is no space to place the materials.  The patient is robbed of the ability for an even better regenerative outcome.

The Case for Erbium Lasers in Periodontal Therapy

Erbium lasers (Er:YAG or YSGG) offer the same apparent periodontal benefits as the Nd:YAG: bactericidal effect and ablation of inflamed and diseased pocket epithelium.  Additionally, a space is maintained in the pocket, allowing the concomitant use of regenerative products to further enhance the healing.  De-epithelialization can then be performed with an Erbium or CO2 laser to inhibit epithelium downgrowth and prevent the formation of a long junctional epithelium.  De-epithelialization can be done at post-op visits for as long as needed to help achieve the desired results.

Doesn’t that make more sense, fellow Laser Dentists?

The Nd:YAG and LANAP seem great in mild or moderate cases, but where intrabony defects are involved or where a higher level of regenerative predictability is desired, comprehensive laser periodontal therapy with an Erbium laser is the way to go.  More Lit Reviews to follow.

Comments?  Thoughts?

My Journey

I initially investigated incorporating a laser into my practice early in 2008.  I am a periodontist, and as you may or may not know, there is a general lack of laser awareness in the periodontal community.  It is a complex issue that will be addressed separately.

I decided to research lasers independently.  I read countless studies, spoke to laser Continue reading “My Journey”

Biolase – YSGG: FDA Clearance Calculus Removal

Dec 9, 2009: http://www.marketwire.com/press-release/BIOLASE-Announces-FDA-510k-Clearance-Its-Waterlase-MD-Laser-Removing-Calculus-Patients-NASDAQ-BLTI-1087883.htm

I’m still waiting to see the studies that clearly demonstrate this, because I have tried removing calculus with the YSGG on freshly extracted teeth and it doesn’t come off easily.  Granted, intra-orally with the presence of saliva it might work, but????

EXCERPT: BIOLASE Announces FDA 510(k) Clearance of Its Waterlase MDTM Laser for Removing Calculus in Patients With Periodontal Disease Minimally-Invasive Treatment for Condition Impacting Over Half of Americans Over 55

IRVINE, CA–(Marketwire – December 9, 2009) – BIOLASE Technology, Inc. (NASDAQ: BLTI), the world’s leading dental laser company, today announced that it has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market its Waterlase MD™ laser system for removal of subgingival calculi to prevent and treat periodontitis, the greatest cause of tooth loss for adults over 35 and a condition impacting more than half of Americans over the age of 55, as reported by the American Academy of Periodontology (AAP).

AAP News Comment

I just received the Oct-Dec 2009 American Academy of Periodontology’s News Bulletin.  In Dr. Samuel B. Low’s President’s message he states the following about lasers and periodontists:

“…As an example, we should have determined the feasability, yes or no, of using lasers.  We should have been involved as a profession.  We looked the other way, and now we’re down on the food chain.”

No kidding, doc.  So what are you going to do about it?  Is it just me or does it seem that the AAP is all talk, no action.