Easier for clinicians, better for patients
by Dr. Jeanette MacLean
During my first decade of clinical practice, I thought sealant
“success” meant retention of the bulk of material. Retention
is a frequent metric mentioned in sealant studies, and
my formal dental education led me to believe resin was the
preferred sealant material because it does not wear.
Unfortunately, a lot of my misconceptions about glass ionomers
were the result of a lack of training and limited experience with the
material. I previously believed glass ionomer should be used only as a
liner or crown cement because it would “wash out.”
In my private pediatric dental practice, the patients often stay
from the time they are toddlers until they are in college—a perfect
opportunity to see which materials and techniques truly stand the
test of time. Over time, I noticed a recurring problem under my older
patients’ leaking or chipped resin sealants: Decalcification or frank
cavitation of the underlying enamel. This observation coincided with
my adoption of minimal interventions for caries management and
increased usage of glass ionomer restoratives.
I no longer judge a sealant based on retention of the sealant material,
but rather its ability to prevent caries. Glass ionomer cement
(GIC) fissure sealants are as effective as resin-based fissure sealants in
the prevention of dental caries in the permanent dentition of children.1 However, several key physical properties of GIC make it a
superior choice of material for sealants.
Key benefits
1. Hydrophilic. Glass ionomer sealants are hydrophilic and can be
placed on a moist surface. GIC works better in a wet field, making
it easier for clinicians to handle.2 GIC also has the unique ability to
adhere to moist enamel and dentin without necessitating an intermediate
agent.3 It frustrated me that sometimes I couldn’t achieve
the isolation necessary for resin sealants because of a patient’s poor
cooperation, dental anxiety, strong gag reflex or special needs—even more frustrating because these were often the patients whom sealants
would benefit the most!
GIC can even be placed on partially erupted molars—a big no-no
for resin. This is a huge advantage of GIC sealants, because partially
erupted molars present a serious clinical challenge when they
erupt into young mouths before the mandible has adequate arch
length to accommodate them. Instead of taking a few weeks to erupt,
the process may take months or even years, trapping food under the
operculum in the meantime, and sometimes decaying the permanent
molar before it has fully erupted. These isolation issues are no longer
a concern now that I’ve switched to hydrophilic GIC sealants.
2. Fluoride release. GIC sealants release and recharge with fluoride,
resulting in a caries prevention effect that is not retention-dependent.
Loss of resin sealant retention, however, is associated with
the risk of developing caries. Even when we think the bulk of a
low-viscosity glass ionomer cement (LVGIC), such as Fuji Triage
from GC America, has disappeared, small particles remain in the
bottoms of fissures, acting as fluoride reservoirs that enhance nearby
enamel remineralization. After 28 days, enamel adjacent to GIC contains
1,181.03 parts per million more fluoride than enamel adjacent
to fluoride-containing resin.4
Don’t want LVGIC washout? Use a more wear-resistant high-viscosity
glass ionomer cement (such as GC America’s Fuji IX) or a glass
hybrid restorative (such as GC America’s Equia Forte).
3. Chemical bond. GIC sealants chemically bond to enamel via
ionic crosslinking between the material and the tooth surface. Using
a 20% polyacrylic acid cavity conditioner before applying a GIC
sealant increases chelation between the enamel and the GI matrix,
establishing a more stable bonding surface.5 Upon closer examination
with scanning electron microscopy, you can see a chemical fusion
zone established between the enamel and GIC, but it is difficult or
impossible to see where one ends and the other begins.6
Chemical bonds are superior to resin tags because they are not
prone to detachment or marginal breakdown. Over time, resin sealant
can leak at the margins and develop caries underneath. This is
a reason parents have used to decline having their children’s teeth
sealed. I’ve heard stories like, “My dentist found a cavity under my
old sealant that was so deep, I needed a root canal.”
Ironically, my one and only cavity was found during my early
20s by a dental school classmate under an old resin sealant on the distal lingual groove of my maxillary left second permanent molar.
My sealant had leaked and chipped and was subsequently filled by
my professor. (Thank you, Dr. Gardner Beale.) When playing the
long game, glass ionomer is the sealant material of choice thanks to
its chemical bond.
4. Biocompatible and antimicrobial. Glass ionomer is the most
tooth-like dental material we have. Some parents have declined sealants
for their kids based on concerns about plastic and bisphenol A
(BPA). GIC sealant is BPA-free, contains zero resin monomers and
has been proven safe and effective after decades of clinical use. GIC
is antimicrobial, inhibits biofilm attachment and prevents damage
from acid and bacteria on the tooth surface by creating an inhibition
zone. Caries resistance from GIC at the cavosurface and adjacent
smooth surface has been shown in both in vitro and in vivo studies.
The minerals released from GIC facilitate remineralization of
enamel and prevention of lactobacilli and Streptococcus mutans bacterial
growth on treated tooth surfaces as well as adjacent surfaces,
reducing the risk of secondary caries.7 In essence, GIC sealants “share
the love” with the sealed tooth and its neighbors.
5. Better for community health and school settings. Thanks to
their lower technique sensitivity, good adherence, fluoride-releasing
properties, and additive effect of being a sealant and fluoride provider
for the prevention of occlusal caries, a 2018 systematic review and
meta-analysis from the Journal of the American Dental Association identified
GIC-based sealants as a good alternative to resin-based sealants,
“specifically in community procedures when there is limited equipment,
no chairside assistant for the dentist or dental hygienist, and
a considerable number of children at high risk of developing caries.”
A six-year study of a comprehensive, multicomponent, school-based
prevention program with 6,927 children in 33 U.S. public
elementary schools published in 2021 demonstrated a 50%
reduction of untreated caries. This program is an excellent example of the public health benefit of GIC sealants, which were used along
with dental examinations, twice-yearly prophylaxis, glass ionomer
interim therapeutic restorations, fluoride varnish, toothbrushes,
fluoride toothpaste, oral hygiene instruction, and referral to
community dentists as needed.8
Quick, effective, easy
I have seen dentists chat online about all the elaborate steps
they take to place resin sealants—air abrasion, rubber dam,
bonding agent, etc. This takes an insane amount of time, additional
equipment and higher overhead, and still will not be tolerated by
patients who are highly phobic, have a strong gag reflex or have
special needs. More importantly, it does nothing to help the masses
of children who lack access to dental care.
I think back to the ridiculous 45-minute separate appointments
with nitrous oxide we used to schedule for routine resin sealants.
On any given day, kids would come to their appointment only to
refuse the nitrous nose, not tolerate the bite block, gag for cotton
isolation or freak out at the sight of the etch syringe (mistaken for a
“shot”), forcing us to abandon the mission. Some parents never even
bothered to schedule the additional appointment for sealants—
after all, it was hard enough to get them in for their six-month
checkup. And then, of course, if I had a dollar for every patient
chart that used to read “waiting on sealants due to maturity,” I’d
have a whole lotta dollars. Talk about a waste of time and missed
opportunity!
It’s almost comical how we used to unnecessarily overcomplicate
things, simply because we just didn’t know any better. Maya
Angelou once said, “Do the best you can do until you know better.
Then when you know better, do better.” Now that I know the
benefits of glass ionomer sealants, I can help more patients in a
more efficient and effective manner, and I will never look back.
I can now seal all four first permanent molars in less than five
minutes, with one capsule of GIC, right at the patient’s recall
exam. The kids are happy because it’s quick, simple and painless;
the parents are grateful because they don’t need to schedule an
additional appointment; the teeth benefit from GIC’s superior
material properties; and our bottom line benefits from increased
production. Everyone wins!
12 Steps to Success:
Applying Glass Ionomer
Cement (GIC) Sealants
1. Clean the tooth with plain pumice and rinse.
2. Apply 20% polyacrylic acid cavity conditioner
(such as Cavity Conditioner, GC America)
for 10 seconds with a microbrush.
3. Rinse off the conditioner with water.
4. Gently dry—but do not desiccate—
the tooth to remove excess water.
5. Tap the GIC sealant capsule
(here, Fuji Triage from GC America)
on its side to loosen the glass particles.
6. Activate the capsule by firmly
depressing the colored plunger on
the bottom against the countertop.
7. Mix the capsule for 10 seconds
in a capsule mixer.
8. Place the capsule into the applicator
gun and click two or three times to
move the material up toward the tip.
9. Immediately apply the material to the
tooth’s pits and fissured grooves with
the capsule applicator.
10. Quickly adapt the GIC to the
tooth with a damp microbrush
or cotton-tip applicator.
11. Let the material auto-cure
for 2½ minutes.
12. Instruct the patient to eat
only soft foods for 48 hours.
To download a free copy of Dr. Jeanette MacLean’s
glass ionomer cement postoperative instructions form
for patients,
click here and
under the Silver Diamine Fluoride pulldown menu,
select “Resources for Dental Professionals.”
To watch a video tutorial for sealant application,
click here.
Reference
1. Seth, S. “Glass Ionomer Cement and Resin-Based Fissure Sealants Are Equally Effective in Caries
Prevention.” J Am Dent Assoc. 2011 May; 142(5): 551–552.
2. Oba. A.A., Dülgergil, T., Sönmez, I.S., and Dogan, S. “Comparison of Caries Prevention With
Glass Ionomer and Composite Resin Fissure Sealants.” J Formos Med Assoc. 2009 Nov; 108(11):
844–848.
3. Gurgan, S., Kutuk, Z.B., Yalcin, Cakir F., and Ergin, E. “A Randomized Controlled 10-Year
Follow-Up of a Glass Ionomer Restorative Material in Class I and Class II Cavities.” J Dent. 2020
Mar; 94: 103–175.
4. Mickenautsch, S., Mount, G., and Yengopal, V. “Therapeutic Effect of Glass Ionomers: An Overview
of Evidence.” Aust Dent J. 2011 Mar; 56(1): 10–15.
5. Alirezaei, M., Bagherian, A., and Sarraf Shirazi, A. “Glass Ionomer Cements As Fissure Sealing
Materials: Yes or No?: A Systematic Review and Meta-Analysis.” J Am Dent Assoc. 2018 Jul;
149(7): 640–649.
6. Milicich, G. Journal of Microscopy, Vol. 217, Part 1, January 2005, 44–48.
7. Hicks, J., Garcia-Godoy, F., Donly, K., and Flaitz, C. “Fluoride-Releasing Restorative Materials
and Secondary Caries.” Dent Clin North Am. 2002 Apr; 46(2): 247–276.
8. Starr, J.R., Ruff, R.R., Palmisano, J., Goodson, J.M., Bukhari, O.M., and Niederman, R.
“Longitudinal Caries Prevalence in a Comprehensive, Multicomponent, School-Based Prevention
Program.” J Am Dent Assoc. 2021 Mar; 152(3): 224–233.
Dr. Jeanette MacLean,
a member of Dentaltown’s
editorial advisory board,
is a private practice
pediatric dentist and
the owner of Affiliated Children’s Dental Specialists in Glendale,
Arizona. She is an internationally recognized
expert and advocate of minimally invasive
dentistry.