Why I think Calcium Hydroxide
Should be used in Root canal
Be sure to read my other articles on this site [ See "Topics/Info" ] on
Root Canal Treatment to get the full story about my views regarding
root canal treatment.
Since you are reading this there's a
good chance you are thinking [or are sure] that you need a root canal.
Also, you have probably been reading lots of conflicting ideas about
whether root canals are "good" or "bad". If you are
holistically or "alternative medicine" oriented, you have probably read
information suggesting that all root canals will make you sick and
cause all sorts of problems in your body - both near and far away from
that tooth. You may be familiar with the writings of Dr. Weston
Price or Dr. George Meinig, both of which will scare the heck out of you
when it comes to root canal treatment!
I am a general
dentist that tries to be holistically oriented in my treatment, and I try to find reasonable
approaches rather than black-or white dogmatic ones. I try to
consider and balance what we can learn from scientific research with what
has been suggested by the alternative healing community.
Many times, even if absolute scientific proof does not yet exist, the
ideas coming from the alternative community seem to make sense and urge us
to at least attempt to honor them by modifying our techniques as long as
they don't totally conflict with what has been shown scientifically
to be valid.
If you are not already familiar with
the basics about just what root canal treatment "is", the following
is a brief description:
The anatomy of a tooth is like this:
There is a hollow space running down the center of each root.
That is the nerve canal. It can have curves and small offshoots or branches to make it
more complex than a straight "tube", but in all, that total space is the nerve-
or root-canal space. In a healthy tooth the nerve and small blood vessels occupy
that space. When root-canal treatment is done, that canal is cleaned out to render it
empty. Medications are usually used to "sterilize" that space...to kill any
bacteria that might be remaining after physically cleaning it out. Then it is filled up
with various techniques and materials to obliterate the space.
What we know is that it is
actually more complex than
that. Not only is there this large central nerve-canal space to worry about, but, rather,
that there are millions of little tunnels coming off the central nerve-canal space
radiating through the body of the tooth root to the exterior surface of the tooth root.
The tooth root surface is in contact with the blood stream and then bone. The "little
tunnels" or dentinal tubules, as they are correctly called comprise literally
of tunnels into which bacteria from the nerve-canal space can go and hide, well away from
the physical and chemical efforts of the dentist. This has been shown and
by the electron-microscope!
What does all this mean? What are the implications? Well it seems to me
there are several. First, it seems ever more important to do the root-canal treatment as
early as possible. In addition to making the treatment easier for you, it minimizes the opportunity for infection to develop inside the tooth which
might be able to subsequently hide in the tubules and from there spread havoc around your
There are basically three steps
to doing root canal treatment. First,
the nerve tissue inside the hollow nerve canal(s) is removed with
tiny steel instruments, starting with very narrow ones and gradually using
larger and larger ones to clean it out as completely as possible.
The larger sized ones are still only about 1/32 of an inch thick.
That removes the bulk of the remaining tissue inside the tooth root.
Since there is still some tissue
remaining that can't be removed with metal instruments, and since there
will likely be bacteria, bits of tissue, and products of infection [pus etc.] in
there, chemicals are used in the Second Step
to remove them in an attempt to "sterilize" the canal space.
Recently lasers have been sometimes used for this. I have written
another article just on the topic of laser-assisted root canal treatment
on this site, so I won't go into detail here except to say that
while it "sounds" like it may be a good idea, the jury is not yet in
on it and there are possible reasons why it might NOT be a good
idea. Time will tell....
when to tooth has become comfortable and efforts have been used to
get the canals as sterile as possible, then the hollow space in the nerve
canal is totally filled up so fluid and bacteria cannot collect again in
there. Several different materials and techniques are available to
do this. It is technically a tricky and difficult job, so
often the dentist will use the materials and technique that he/she is most
comfortable and skilled with. It would be very difficult to prove
that one material or one technique is better than the others, but only
that a particular dentist might do a better job with a technique
he/she is "good at". While we "can" learn new techniques, it takes
time and practice to get good at any one of them... so we each tend
to use what works for us.
What about the Calcium Hydroxide?
Having established the basic
groundwork above I will now focus on the second step
of the root canal treatment: Chemical Cleaning and
Disinfection. The information was reiterated in an
article published in dentalCEtoday.com
in the February 2010 edition.
The author states that "it has
been shown that the number of bacteria can be significantly reduced, but
not [eliminated]" by mechanical instrumentation used in the first
step of treatment.
Therefore, he says, the
mechanical instrumentation must be augmented with antimicrobial
irrigant. Sodium hypochlorite - similar to Clorox Bleach - is almost
universally the irrigant of choice in root canal treatment, and has been
for many, many years. Various strengths of it are used but the
research shows a wide range of helpful dilutions with not much
difference in effect. It is very helpful for a couple of reasons.
First it is highly antimicrobial for the vast majority of bacteria,
viruses, spores, fungi and protozoa found in root canals. Secondly it
chemically helps to actually "dissolve" remaining bits of tissue
that could not be removed with the metal instruments. It
is the only irrigant that can disrupt and remove microbial
biofilm from the infected root canal system. Research,
however, has shown that Sodium hypochlorite, while almost universally
depended on, will not completely kill all the bacteria in the tooth in up
to at least 50% of cases studied. Research over many,
many years has shown that the addition of Calcium hydroxide as a
medication inside the canal significantly further reduced bacteria.
Many different medications inside
the root canal have been used over the years and all require much
more than a few minutes of use in the canal to be effective. Root canal treatment
done in only a single office visit limits medication use to minutes
- rather than hours or days or weeks as in the case of multiple visit
treatment. According to Bystrom, a well respected researcher in
endodontics [root canal treatment], leaving Calcium Hydroxide inside
the canal for 4 weeks [which is what I do routinely] renders
the canals bacteria free in 97% of cases studied.
Other medications commonly used
like CMCP or phenol only succeeded in about 66% of cases. Other
research using Calcium Hydroxide, but for SHORTER
periods of time, like one or two weeks, showed no
significant improved effectiveness over the CMCP or Phenol. It seems
very important to me to leave the Calcium Hydroxide in the canals for at
least 4 weeks for maximum effectiveness.
Calcium Hydroxide work? It is a very alkaline [ high pH
of up to pH of 14 or so ]. Being so alkaline it does several good
things. It dissolves little bits of remaining tissue that the metal
files missed. It dissolves the cell membranes of bacteria, which
can cause toxicity even when the bacteria are dead, but by
dissolving this cell wall, it eliminates the toxicity effect.
Also the Calcium Hydroxide gradually dissolves into the moisture in the
miles of tiny tubules that make up the dentin from the nerve canal out
almost to the outside surface of the tooth root. We know that
bacteria can and do get stuck in these tiny tube-like tubules and
can effectively "hide" away from our cleaning efforts in the main nerve
canal space. As the Calcium Hydroxide dissolves deeper and deeper
into the tubules it can kill bacteria hiding there.
Research has demonstrated that a
change in pH up to 14 can be measured out at the outside surface of tooth roots
treated with Calcium Hydroxide,
indicating that it has penetrated from the nerve canal out to the surface.
Does it penetrate every single tubule that way? We can't say
that we know it does but it would seem reasonable to assume it probably
does come close to that. If we drop some salt into a bucket of
water, it dissolves out the same way and does not miss some of the
For peer-reviewed research
Journal of endodontics, volume 22, Number 8, August 1996
Changes in ph at dentin surface in roots obturated with
calcium hydroxide paste
Effect of 2% chlorhexidine gel mixed with calcium
hydroxide as an intracanal medication on sealing ability of
permanent root canal filling: a 6-month follow-up
Department of Endodontics, University of Athens,
Efficacy of calcium hydroxide: chlorhexidine
paste as an intracanal medication in bovine dentin
Some of the
Calcium Hydroxide dissolves out into the bone around
the end of the root where the bone normally gets damaged by
the root canal infection and the changes in chemistry that
result from it. The Calcium Hydroxide helps to change this altered
chemistry back to normal and calms the bone [ which is where a lot
of the pain comes from ] and helps to initiate bone repair
processes to speed healing.
All of these helpful effects of
Calcium Hydroxide are gentle and slow.
That's why leaving it in the tooth for one or two weeks is not so
very effective. But given enough time it gently helps in all
those ways described above. It should not be left for more
than 6 weeks, however, because it gradually begins to dissolve out and that
would just create space for fluid and bacteria to collect again.
So, I try for 4 weeks. In special cases I will go 6 weeks, remove it
and place a fresh dose of it for another 4 to 6 weeks.
Here's an example of a badly
infected root canal with lots of bone loss -"cavitation" - and the result
of my treatment using calcium hydroxide. Would the result have been
the same using conventional treatment? Perhaps. We can't
know for sure. But this is the kind of result I have seen over the
years.... if not every time, certainly by far most of the time. Keep in
mind that NO treatment can boast 100% success - mine or anybody else's,
conventional or "holistic", with laser, ozone, supplements, antibiotics,
Are there any problems with
Calcium Hydroxide does many wonderful things, it has
been found to lack in one area. There are two microbes important in
root canal treatment that it does not kill: Candida
and E- faecalis. When root canal treatment fails as it
sometimes does, very often E faecalis is found in the re-infected
canals and it is often thought to be responsible for the failure.
Fortunately, chlorhexidine has been found to be very effective
Calcium Hydroxide have been shown to have additive
Candida and E- faecalis. That is, the
mixture is more effective than either one alone. I have
been using such a mixture now [Feb. 2010] for a few years and have
found it to be very effective in reducing discomfort and promoting good
healing. with absolutely zero negative side effects that I
have seen. In the article mentioned above, the author
states that the mixture, when used for 4weeks [ which is
exactly what I have been doing ] reduces the inflammation in the
periodontium [ the supporting bone and soft tissue around the
tooth root ] and results in less root resorbtion [damage to the root].
Chlorhexidine, which you may have
seen or used in the form of "Peridex", a prescription mouth rinse for
periodontal problems, can be used along with Sodium hypochlorite as a
canal irrigant. It is safe and innocuous except to the germs
that reside in the mouth and root canals!
Calcium hydroxide, in my opinion,
while a very "old" root canal medication, is
still recognized to be more effective than other more "modern"
medications, but is only infrequently used and usually only for special
situations. From my point of view, there is no
reason why it should not be routinely used and for a long enough time
period to do the job (about a month). The norm today among
most general dentists as well as
most root canal specialists is to either finish
the treatment in one appointment or perhaps in two
appointments about a week apart.
It takes extra time and effort to treat root
canals with calcium hydroxide, so it is often seen as "inefficient" or a
waste of time, since the single visit techniques seem to work well enough
for most patients.
Most root canal specialists -
endodontists - were trained in the calcium hydroxide technique, so
most of them do know how to do it properly, but at the same time most of
them don't seem to think the extra time and effort is worth it, except in
special problem cases.
research articles regarding calcium hydroxide + chlorhexidine used
together, for those of you that like to read such things:
Source: Department of Restorative
Dentistry, São Paulo State University-UNESP, São José dos
Campos, São Paulo, Brazil.
AIM: The aim of this paper was to evaluate the
antimicrobial activity of 2% chlorhexidine
gel (CLX) associated with various
intracanal medicaments against Candida
albicans and Enterococcus faecalis inoculated in root canals.
METHODS: It was verified that the instrumentation with CLX reduced
the number of CFU/ml significantly when compared with the confirmation
collection (control). However, the use of the ICM was only capable to
eliminate completely the microorganisms in the root canals without
difference statistics between them.
CONCLUSION: Although the use of 2% chlorherixidine
gel reduces the number of
microorganisms significantly, only the ICM [intracanal
medication] calcium hydroxide and
calcium hydroxide associated with
chlorhexidine are able to eliminate
these microorganisms completely.
CHX and Ca(OH)2
[Chlorhexidine and Calcium Hydroxide]
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Oct;102(4):544-50. Epub 2006 Aug 4.
In vitro evaluation of the antimicrobial activity of calcium hydroxide combined with chlorhexidine gel
used as intracanal medicament.
Gomes BP, Vianna ME, Sena NT, Zaia AA, Ferraz CC, de Souza Filho FJ.
The aim of this study was to investigate the antimicrobial activity of calcium hydroxide (Ca(OH)2) combined with 2%
chlorhexidine gluconate (CHX) gel against endodontic pathogens and to compare the results with the ones achieved by
Ca(OH)2 mixed with sterile water and by CHX gel alone. Two methods were used: the agar diffusion test and the direct
contact test. Ca(OH)2 + 2% CHX gel produced inhibitory zones ranging from 2.84 to 6.5 mm, and required from 30 seconds
to 6 hours to eliminate all tested microorganisms. However, 2% CHX gel showed the largest microbial growth zones from
4.33 to 21.67 mm, and required 1 minute or less to inhibit all tested microorganisms. A paste of Ca(OH)2 plus sterile
water inhibited only the microorganisms with which it was in direct contact and required from 30 seconds to 24 hours
to kill all tested microorganisms.
In conclusion, 2% CHX gel + Ca(OH)2 showed better antimicrobial activity
than Ca(OH)2 manipulated with sterile water.
Antibacterial efficacy of calcium hydroxide and chlorhexidine gluconate
irrigants at 37 degrees C and 46 degrees C.
Evanov C, Liewehr F, Buxton TB, Joyce AP.
This study investigated the ability of two endodontic irrigants to eliminate Enterococcus faecalis from
dentinal tubules, and whether their antimicrobial action was enhanced by heat. The lumens of disks
prepared from extracted bovine roots were infected with E. faecalis and incubated for 72 h. Specimens
were then filled with saline, 10% calcium hydroxide (Ca(OH)2), or 0.12% chlorhexidine gluconate (CHX) at
24 degrees C or 46 degrees C and incubated at 37 degrees C or 46 degrees C. The samples were then
pulverized and plated to quantify residual bacteria. No statistical difference (p > 0.05) in bacterial
growth was seen between the two saline groups, or between the two medication groups at a given temperature.
CHX and Ca(OH)2 at either temperature produced significantly less growth than either saline group, and
CHX or Ca(OH)2 at 46 degrees C produced significantly less growth than either group at 37 degrees C.
Heat enhanced the antibacterial action of both experimental irrigants against E. faecalis, but heating
saline produced no increase in bactericidal effect.
Eur J Oral Sci. 2004 Aug;112(4):326-31.
In vitro antibacterial effect of calcium hydroxide combined with chlorhexidine or iodine potassium
iodide on Enterococcus faecalis.
Siren EK, Haapasalo MP, Waltimo TM, Orstavik D.
Several studies have shown a higher success rate of root canal therapy when the canal is free from bacteria
at the time of obturation. Treatment strategies that are designed to eliminate this microflora should
include agents that can effectively disinfect the root canal. Enterococcus faecalis is often associated with
persistent endodontic infections. While in vivo studies have indicated calcium hydroxide to be the most
effective all-purpose intracanal medicament, iodine potassium iodide (IKI) and chlorhexidine (CHX) may be
able to kill calcium hydroxide-resistant bacteria. Supplementing the antibacterial activity of calcium hydroxide
with IPI or CHX preparations was studied in bovine dentine blocks. While calcium hydroxide was unable to kill
E. faecalis in the dentine, calcium hydroxide combined with IKI or CHX effectively disinfected the dentine.
The addition of CHX or IKI did not affect the alkalinity of the calcium hydroxide suspensions. It may be
assumed that combinations also have the potential to be used as long-term medication. Cytotoxicity tests
using the neutral red method indicated that the combinations were no more toxic than their pure components.
J Endod. 2003 May;29(5):338-9.
Efficacy of calcium hydroxide: chlorhexidine paste as an intracanal medication in bovine dentin.
Evans MD, Baumgartner JC, Khemaleelakul SU, Xia T.
The purpose of this study was to evaluate the antibacterial efficacy of an intracanal medication composed
of calcium hydroxide with 2% chlorhexidine. Dentin from 24 bovine incisors was used. The incisors were made
into standardized cylindrical segments of dentin and infected with Enterococcus faecalis. They were then
treated with an intracanal paste composed of calcium hydroxide and sterile water or an intracanal paste
composed of calcium hydroxide and 2% chlorhexidine for 1 week. Dentin shavings were collected, suspended
in solution, and spread on brain-heart infusion agar. After incubation, colony-forming units were enumerated.
The amount of bacteria per mg of dentin was determined. The calcium hydroxide paste with 2% chlorhexidine was
significantly more effective at killing E. faecalis in the dentinal tubules than calcium hydroxide with water.
Int Endod J. 2003 Apr;36(4):267-75.
Effectiveness of 2% chlorhexidine gel and calcium hydroxide against Enterococcus faecalis
in bovine root dentine in vitro.
Gomes BP, Souza SF, Ferraz CC, Teixeira FB, Zaia AA, Valdrighi L, Souza-Filho FJ.
AIM: To evaluate the effectiveness of 2% chlorhexidine gluconate gel and calcium hydroxide (Ca(OH)2)
as intracanal medicaments against Enterococcus faecalis.
METHODOLOGY: One hundred and eighty dentine tubes prepared from intact freshly extracted bovine maxillary
central incisors were infected in vitro for 7 days with E. faecalis. The specimens were divided into four
groups, according to the intracanal medicament used, as follows: Group 1: 2% chlorhexidine gluconate gel;
Group 2: calcium hydroxide in a viscous vehicle (polyethyleneglycol 400); Group 3: 2% chlorhexidine
gluconate gel + calcium hydroxide and Group 4: Brain Heart Infusion (BHI) broth (control group).
The medicaments were placed into the canal lumen and left there for experimental times of 1, 2, 7, 15
and 30 days. After each period, irrigation with sterile saline to remove the medicament was performed
and the canals were dried with sterile paper points. Dentine chips were removed from the canals with
sequential sterile round burs at low speed. The samples obtained with each bur were immediately collected
in separate test tubes containing BHI broth. The tubes were incubated at 37 degrees C and daily observed
for microbial growth, visualized by the medium turbidity.
RESULTS: Chlorhexidine gel alone completely inhibited the growth of E. faecalis after 1, 2, 7 and 15 days.
Calcium hydroxide allowed microbial growth at all experimental times. The combination of chlorhexidine and
Ca(OH)2 was effective after 1 and 2 days demonstrating 100% antibacterial action; however, its antibacterial
activity reduced between 7 and 15 days.
Update 2014: I have been using a
mixture of calcium hydroxide mixed with 2% chlorheidine up to the present
time with very good results. Up until a few years ago I used it but
with much lower concentration chlorhexidine and before that, only mixed
with distilled water.
I hope this information has been
helpful to understand root canal treatment options. There is a lot
of confusing and contradictory information floating around on the
internet. Read it all if you can and see what makes the most sense
to you. Good luck!
Michael C. Goldman, DDS
General and Cosmetic Dentistry
3815 East-West Highway
Chevy Chase, Maryland 20815 Phone (301) 656-6171
Michael Goldman DDS
3815 East-West Highway
Chevy Chase, Maryland 20815
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to dental treatment, primarily caring for patients' health and safety from
both a conventional as well as "alternative healthcare" point of view.
It is sometimes called "biological" dentistry or
"biocompatible" dentistry. In it's fullest sense, I believe it
acknowledges and deals with the mind, body and spirit of the patient, not just his
or her "teeth". See Topics / Info.....
Cosmetic dentistry is about doing
quality , esthetic dentistry in a way that looks natural to begin with, and
furthermore, can even improve one's attractiveness through
techniques such as bonding, bleaching, veneers, caps, implants and more. It can
be like "instant orthodontics" in correcting crooked, twisted or
misplaced teeth in many instances. Dark or misshapen teeth can be restored.
Smiles that lack youthful vigor or beauty can be revitalized! See Topics / Info..
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