Resin composite restorations have a shorter lifespan than other restorative materials. We talk to experts to learn how clinicians can prolong the life of their restorations.
Resin composite materials are a popular restorative material, but when compared to other materials, their longevity leaves something to be desired. However, there are things you can do to make composite restorations last longer.
Composite materials have many advantages for restorative dentistry. Most importantly, you preserve as much healthy tooth as possible when you restore caries with composite. In addition, composite restorations are undetectable because the materials blend in with the tooth. Resin composites also bond to the patient’s tooth quickly.
That said, resin composite restorations have one main disadvantage. They don’t last as long as other fillings.
Most experts agree that composite restorations last from five to seven years. Some say 10 years. That sounds like a decent length of time until you compare to other restoration materials. For example, amalgam can last from 10-15 years, and the same goes for ceramics and gold.
Sure, these other restorative materials have disadvantages, too. For example, amalgam requires you to remove more healthy tissue from the patient’s natural tooth, and gold and ceramic fillings are expensive. However, when compared to the durability of composite resin, longevity is not one of their problems.
Part of the reason composite resin restorations have shorter life spans has to do with execution. Using composite is technique sensitive and product-specific. Tim Bizga, DDS, FAGD, a private practice general dentist in Cleveland has adopted a saying that he uses when he trains in seminars and when he runs his practice: “Complexity is the enemy of execution.”
Dr. Bizga says that however the product is formulated, the difference in the dentist’s experience often has to do with the clinical situation and the patient in the chair. Composite resin materials have many steps that are precise in their execution and that vary by manufacturer. While that isn’t a problem by itself, when you take into account that the patient in the chair could be a child or a patient with special needs, it complicates the situation.
“Now you have less than ideal circumstances, which is what most dentists encounter,” Dr. Bizga explains. “Everybody is trying to do the right thing. It just doesn’t always work out because that’s life.”
The popularity of composite resins for restorations shows that the advantages outweigh the disadvantages in most dentists’ minds. So, what can clinicians do to prolong the lifespan of our resin composite restorations? A few things, according to our experts. Here’s what they had to say.
Isolate, isolate, isolate
Sarah Jebreil, DDS, AAACD, has a private practice in Newport Beach, California, that specializes in cosmetic dentistry. She says for both anterior and posterior restorations with resin composite, one of the most significant factors in composite longevity is isolation because of the adhesion required.
“If you are not in a dry environment, and you have any moisture, that will definitely decrease the bond strength,” Dr. Jebreil says.
“All resin systems to my knowledge require good isolation. That’s the hallmark,” Dr. Bizga agrees. “If you look at the case and don’t know if you can get it, you have got to have alternatives in the office.”
Of course, isolation has many challenges in the oral environment. Dr. Jebreil says that some patients have more moisture than others in their mouths. Also, the type of isolation a dentist uses can affect how dry the area is. Rubber dams are ideal but also time-consuming. Dr. Jebreil says that can mean dentists in a hurry might choose a different way to isolate that isn’t as effective as the dam.
“There is a multitude of factors,” she explains.
Dr. Bizga likes the Dry Shield® Isolation System. He says that it helps him get the isolation he needs to facilitate the bond. However, he says while Dry Shield takes care of saliva, it doesn’t help with bleeding around the tooth itself.
One way to help with bleeding is using dental lasers to cauterize the area. Sometimes it means packing cord. However, you choose to control the bleeding, Dr. Bizga says it is essential.
Polish the margins properly
Sometimes restorations are compromised at the margins because of staining and bacteria accumulation there. One way to help prevent this situation per Dr. Jebreil is to polish the margins properly. Margins need a smooth finish to make the surface less hospitable to bacteria and other contaminants.
“When you are done with the restoration, you always want to check the margins and make sure they are adequately polished,” Dr. Jebreil says.
Design your prep for success
As a dentist who practices much cosmetic dentistry, Dr. Jebreil has many cases where esthetics are a priority in the treatment. She finds that in the anterior, having an adequate prep design is vital.
For example, when a patient has a chip in the front, Dr. Jebreil likes to design her anterior preps with a wide bevel and chamfer to facilitate retention of the material as well as protecting the enamel margins from leakage. Proper angling of the bevel is crucial depending on the type of material you are using and how you are using it.
“If you don’t have enough surface area, the restoration can just pop right off,” Dr. Jebreil says.
Never forget the fundamentals of occlusion
Dr. Jebreil is also a fan of maintaining the fundamentals of occlusion as well to extend the life of your restorations. The three determining factors of occlusion include the temporomandibular joint or TMJ (the posterior determinant), the teeth (the anterior determinant), and the overall neuro-masticatory system.i They work together in a patient’s mouth to determine the occlusal relationship. Each one must complement the other to keep things running smoothly when the patient chews.
Dentists can only change one part of these three, the teeth.ii Therefore, it is essential to understand and remember the basics of how these three factors work together when practicing restorative dentistry to increase the longevity of your restoration. If any part of the restored tooth is off from the natural shape, it could create interference or excessive force on one of the determinants, which could then lead to earlier restorative failure.
To avoid this outcome, experts agree that dentists should include an examination of the TMJ, the teeth and soft tissue, and the periodontium before you start treatment. Also, you should review all the factors involved that could influence the movements while chewing that could affect how the three parts work together.iii
Understand your materials
Dr. Jebreil says another reason that some restorations do not last as long as they could is that the clinician didn’t understand the materials they were using well enough. She emphasizes that when using composite, it is crucial to follow the manufacturer’s guidelines.
She also recommends finding the material that “works best in your hands.” When you follow the manufacturer’s guidelines that you know by heart, it makes a significant impact on the bond strength as well.
“I always use the BISCO ALL-BOND UNIVERSAL®. I love it. I use it because it works well in my hands and I know how to use it,” Dr. Jebreil says. “But if I were to switch to something else, I would have to read exactly how to use it and make sure my team knows how to use it.”
Every step counts
Dr. Bizga advises dentists to come up with a system that you have in place where you and your assistant are on the same page. Dr. Bizga says that sometimes patients comment on how well he and his assistant work together.
“They’ll sit up and go, ‘You guys are a great team. Like, you didn’t even say a word, and she knew exactly what you wanted next,’” Dr. Bizga says. “And it does happen. Sometimes when you are intensely focused, the conversation stops.”
Dr. Bizga says having that focus and routine allow you to rise to the occasion when you encounter difficulties. For example, if the isolation is beginning to get compromised, you can work through the procedure quickly, so you don’t suffer the consequences of that.
“If you are efficient in knowing what step is next, that every single one counts, and you do them to the best of your ability, you can get through it,” Dr. Bizga says.
One size does not fit all
Dr. Jebreil encourages dentists to consider the patient and the placement when choosing materials. The best chance of survival for the restoration might have more nuances than a one-size-fits-all approach.
For example, if you are working on a patient that has a high risk for caries and you are working on a subgingival restoration where you can’t get sound isolation, maybe you should reconsider a direct restoration in this case. Dr. Jebreil suggests switching to an indirect restoration to get a better seal in this case.
Another example might be a patient who bruxes and needs restoration on the second molar. Many materials might not be suited for this placement, so choose a material that can stand up to the wear the patient will likely apply to it.
“A lot of it is a case-by-case basis,” Dr. Jebreil says. “You should ask yourself, ‘Is this the right material for this tooth in this patient at this time?”
“We have to control moisture, fluid, and contaminants, and if we can’t do that, then you have to look to alternative materials to complete the restoration,” Dr. Bizga says.
Dr. Bizga says some alternative materials can be glass ionomer or amalgam. However, both might not have the esthetic results you and the patient desire. Also, in most situations, glass ionomer has a shorter life span than composite, so it may not be the best alternative if longevity is your goal.