When it comes to bonding a restoration, failure isn't an option.
In the 1995 movie “Apollo 13,” NASA flight director Gene Kranz delivers the inspirational missive “Failure is not an option!” While that was great in an Academy Award-winning movie, the fact of the matter is that the real Kranz never said it. But don’t let that nugget of Hollywood hyperbole distract from the fact that there are times in any endeavor – for dentists, especially when bonding a restoration - when failure is, truly, not an option.
So, how do doctors avoid failure and ensure that they create a strong bond?
“To me, the most important thing is isolation,” says Dr. Sarah Jebriel, DDS, a cosmetic dentist in Newport Beach, California. “You can do everything right, but if you get moisture in there, you’re not going to get a good bond.”
“It doesn’t matter what kind of bonding agent you use - whether you use a first-generation or an eighth-generation one - you’ve got to have good, proper isolation,” says Jeffrey Lineberry, DDS, a general dentist in Mooresville, North Carolina. “Rubber dam isolation is still key for that. The rubber dam has good isolation where you’re minimizing any kind of moisture contamination of the field.”
Rubber dams are simple, uncomplicated devices, yet they remain an effective way to ensure isolation.
“It’s fairly straightforward to use rubber dams,” Dr. Lineberry says. “What you have to do is punch holes in the material to place the rubber dam over the teeth. If that’s not done properly, sometimes you don’t get adequate isolation. You’ll still get a better isolation than not having one at all, but proper placement of it is key.”
Rubber dams aren’t the only way to ensure isolation from moisture.
“If you’re doing a posterior molar, where it’s hard to do rubber dam isolation, there are other options out there, like Isolite, or other products that you could use,” Dr. Jebriel says.
Knowing when to pick your battles is also advised when considering isolation.
"On a patient who has a really big tongue, really big cheeks, or a lot of saliva, maybe doing a bonded restoration in the posterior isn’t the best option. Maybe doing something with a zirconia crown would be better with that kind of patient than relying on a bond because you know you’re not going to get very good isolation back there. It’s also case selection.”
Largely, it’s going to come down to whether or not the doctor thinks he or she can achieve the necessary isolation.
“I have a friend who can do rubber dam on the posterior and cement on a posterior crown,” Dr. Jebriel says. “And if you can do that, then you can do any restoration. But it just depends on yourself and how well you can isolate the area.”
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Follow the instructions
The old adage “When all else fails, read the directions” may seem trite, especially for something as serious as dentistry, but that doesn’t make it any less true. Rather than learn a hard lesson from a failure, the best place to start is by following the manufacturer’s directions in the first place.
Even though the end result is the same, different bonding agents require different steps.
“Sometimes people will grab a bonding agent and treat it like any other bonding agent they have,” Dr. Lineberry says. “Some of them may have specific steps.”
“They are very different,” Dr. Jebriel adds. “It was astounding to me because coming out of school they taught us how to use OptiBond™ Solo, but we never got the instructions. When I got into private practice and started using something else, I used it like I used OptiBond Solo, and that’s how I thought it was. I was getting a lot of failures and I didn’t know why. Then I was reading the guidelines and I came to find out I wasn’t doing it right. Each product is different. The manufacturer does all the testing and knows what works.”
Following manufacturer’s directions is especially important because there are specific indications and conditions for which products have been tested.
“For instance, some dual-curing composite resins that we have out there that we use for bonding indirect restorations in place or using core buildup materials, it’s important to make sure that a particular agent is compatible with those particular uses, especially when you’re crossing brands,” Dr. Lineberry says. “Following manufacturer recommendations is key. For instance, you must have adequate application time. Some manufacturers will recommend 15 seconds of adequate application and scrubbing of the preparation. If you’re doing it for five seconds, if you’re not spending enough time for that, then, obviously, that can impact overall bond strength.”
It isn’t always about the bonding agent one uses. How the case is prepared is also critically important.
“Whatever you’re bonding, whether it’s a composite or a restoration, it’s also about your preparation and the occlusion that you have,” Dr. Jebriel says. “Make sure that your contacts aren’t too high and that you have adequate reduction, if it’s a crown.”
Be sure to also consider how much enamel is available on which to bond.
“For onlays and inlays and things like that, you definitely want to be bonding to enamel,” Dr. Jebriel explains. “That’s where you get your strongest bond, so you definitely want to keep as much enamel as you can, even if you have a great bond. If you don’t have enough reduction, you can still break the restoration. It’s not necessarily the bond that broke, it’s the restoration. You want to have as much enamel as you can to bond to.”
Light-cured bonding agents rely on the proper curing equipment and technique to ensure an optimal bond. Factors involved toward achieving that optimal light cure include:
“A lot of them nowadays are light-cured and, of course, make sure that you have adequate light output. I think that’s kind of key,” Dr. Lineberry says. “Proper positioning for the light is important because that’s been a topic of discussion when it comes to curing restorations in general. It’s easy to set the light on there, but you may have it angled in a funny direction, so you lose some of the intensity of the curing light when you have it at an odd angle.”
“Apollo 13’s” screenwriters, along with actor Ed Harris, are responsible for giving us one of 1990s-cinema’s most inspirational rally cries. But while “Failure is not an option” was never uttered in the NASA control room in the spring of 1970, doctors can still be motivated by its spirit, especially when bonding is concerned.