3 ways mishandling adhesives contributes to restorative failure

Dr. Justin Chi, clinical research associate at Glidewell Laboratories, has firsthand experience with postoperative sensitivity with his restoration-as a patient. After his doctor placed his e.max crown on his #30 First Molar 10 years ago, he couldn’t eat on the right side of his mouth for over a year.

“Every time I bit on it, it was so painful I thought I needed a root canal,” he says. The crown eventually came off (via a Jolly Rancher). When his doctor fixed the crown, she used a desensitizing agent on the tooth, scrubbing it in and following with the same cement. Once the crown went back on, he hasn’t had sensitivity since.

It was an important lesson for Dr. Chi, who wasn’t a dentist at the time. His experience with misdiagnosing his crown adhesive postoperative sensitivity as a compromised tooth “stuck” with him.

“Lots of endodontic procedures are performed every day for post-op sensitivity when in reality it is because of dentists not following the right protocol in adhesive dentistry,” Dr. Chi says.

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Adhesive dentistry has revolutionized the dental practice. However, it requires a bond between the restorative material and the tooth underneath. Success and failure in adhesive dentistry has much to do with how you treat the tooth underneath. Here are three ways mishandling adhesives contributes to restorative failure. 

#1: Forgetting to follow the directions

Every adhesive has instructions, and they all have specific details to them. No matter which adhesive you use, following the directions is paramount to your success. Dr. Alex Kalmanovich, DDS, believes this is the most important aspect of any bonding technique. When dentists begin mixing in their ideas, they start experiencing failures. Dr. Kalmanovich thinks each adhesive’s instructions are essential to its success.

“The companies have done the research. The companies have tested their products. They know what works-but based on their recipe. If you follow that you will be successful and get the results they get. If you start doing other things or forgetting to do certain steps, that’s when you have problems,” Dr. Kalmanovich says.

“With adhesive dentistry, it is all about the technique,” Dr. Chi says. “In a busy practice, you are moving quickly and there are a lot of steps, so you have to be diligent about following them properly.”

Dr. Ford Gatgens, DDS, says several problems can occur for your restoration if you don’t follow the manufacturer’s steps precisely, such as:

• Too little or too much of the adhesive where you don’t want it

• Problems with uniformity from lack of air drying the adhesive adequately

• Materials that preset because the vial wasn’t closed all the way or was exposed to light before it should have been

Dr. Gatgens recognizes that there can be more potential for mistakes when there are more steps to follow. He looks for products with a decreased number of steps, even if that doesn’t result in less time spent on the bonding process.

“If you don’t have three or four individual bottles of something that you have to do things with, you are going to decrease the risk of contamination or another problem,” he explains. 

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#2: Not giving a dam

Isolation is crucial for a successful adhesive restoration. However, it is also one of the most difficult aspects for any dentist in adhesive dentistry.

“Isolation can be challenging,” says Dr. Leah Capozzi, DDS. “We work in a dark, wet environment with cheeks and tongues getting in the way.”

“We don’t want to contaminate the area. We have to make sure the adhesive we put on the tooth is nice and clean. Things like saliva and blood and even certain chemicals like the ones we use to control the bleeding have to be cleaned off properly because if there are remnants left behind it could interfere with the bonded tooth,” Dr. Chi says.

Isolation prevents those contaminants from getting into the working area. In dental school, students learn how to isolate with a dental dam for everything they do. However, once dentists begin their practice, time is money, and the dental dam can feel like an extra procedure that is going to slow them down.

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“When you get into adhesive dentistry, one of the main things that is going to cause it to fail is any moisture or contamination, whether it’s saliva or sulcular fluid or any hemorrhage,” explains Dr. Gatgens. “It’s important to have an isolation system that’s going to work for you. It’s not necessarily saying that it always has to be a rubber dam scenario, but the whole process is predicated on a dry field, and any type of moisture contamination will cause problems long-term.”

#3: Drying it out

Adhesive dentistry success is somewhat of a balancing act between controlling the moisture in the area without drying it out too much. If the area is too wet from water, moisture or saliva, it can interfere with the bond. However, if it’s too dry (especially for bonding to the dentin), the patient could experience postoperative sensitivity.

Dr. Chi says over-drying tends to occur when, during a total-etch process, the dentists check to see that they have a good etch on the tooth surface before bonding. Too much air can desiccate the dentin.

Dr. Chung says he used to have problems with over-drying in the priming step, which led to some problems with post-op sensitivity.

“It goes away,” Dr. Chung said, “but you’d rather it never happened.”

Dr. Kalmanovich sums it up: “So, you want to air dry, but you don’t want to make it bone dry.”

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How to avoid mishandling adhesives

So, how do you avoid these problems? Dr.Capozzi has the following advice for her dental colleagues regarding adhesives:

• Know your adhesive system. Every system has specific instructions that must be followed.

• Isolate. All adhesive dentistry requires a clean, dry surface.

• Review. Ask your assistants to review your systems at weekly or monthly meetings.  Products may change or you may be forgetting a step.

• Take your time. If something goes wrong, stop and start over. 

“We all want to be fast and efficient but not at the expense of the quality of work we provide,” Dr. Capozzi says.  

Dr. Chung adds that you should pick a system that has a broad application that you’re familiar with and you know how to use to avoid confusion between the details of the process.

“Sometimes the steps are a little different. One adhesive is cured for 15 seconds, the other is 20 seconds, or maybe longer. If it's a prime and bond, you must scrub it in and then air dry it and that sort of thing. It can be confusing,” he says.

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Dr. Kalmanovich has a tip for dentists who struggle with isolation. He admits he rarely uses a dental dam, but he does use DryShield, which retracts the tongue, suctions, serves as a bite block and isolates the area.

“It is one of the keys to success in adhesive dentistry,” Dr. Kalmanovich explains. “I use it for my CEREC imaging. I use it for my bonding. It is one of the tricks that is great if you are doing any kind of adhesive dentistry.”

Both Dr. Kalmanovich and Dr. Chi recommend adding a desensitizing agent between etching and bonding to dentin. Dr. Chi is in a unique position to replace restorations that have resulted in post-op sensitivity. He finds that rehydrating the tooth can often resolve the issue.

“Scrubbing it in well will not only rehydrate the tooth, but it also helps to seal off the dentin tubules. And it’s also an antibacterial agent,” Dr. Chi says.

Dr. Gatgens believes that partnering with an excellent materials company will help you achieve success.

“What I have chosen to do is to partner with an excellent company. When I am using their products, I know they are vetted and tested, and they have a high quality.”