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Laura Dorr is the executive editor of DPR's Modern Dental Network.
Simplifying the cement removal process to reduce headaches for both doctors and patients.
Excess cement is a given in restorative procedures, and often one that clinicians may not think about until it becomes a problem. Cement cleanup can quickly go from a mundane occurrence to a major problem in a matter of seconds, particularly when it comes to fast-curing resin cements.
Because the best defense is a good offense, it’s critical to know how to handle the situation if it does arise. Consistency, product awareness, careful execution, and proper curing can make cement cleanup easier—making life easier for you and your patient.
Timing is everything
Navigating curing times with resin cements can be a headache: Cure too long, and the cement hardens too much to remove. Undercure, and the restoration could displace or shift. Finding the balance is key to the success of the restoration—and for cleanup.
“When it comes to excess cement cleanup, the cleanup of glass ionomer is super easy,” says Jason Goodchild, DMD, director of clinical affairs at Premier Dental, in Plymouth Meeting, Pennsylvania. “But when using resin cement, it is vital to understand the tack curing times (and the impact of different curing lights and outputs), self-curing times, final set times, etc. If you mess up the times, excess resin cement can be very challenging to remove. We choose resin because of its strength, so if you don’t clean it up before it becomes sets and becomes strong, you have a problem.”
It’s worth emphasizing that even within a category of cements, different products have different directions, so it’s important to read—and understand—the guidelines for each. Clinicians should be aware of all the factors that impact how it handles and sets. Some resins are designed to be more flexible, while others have a limited window for curing time.
“When we designed our new ZR-Cem Self-Adhesive Resin Cement at Premier Dental, we wanted the cleanup to be easy,” says Dr Goodchild. “This meant some flexibility in tack curing times (one to three seconds) and a defined gel phase at 90 seconds. Other cements don’t offer that kind of advantage, specifically around tack curing times, and if you don’t get it right, cleanup will be frustrating and messy.”
It’s also important to take into consideration other factors that may affect how an adhesive handles or sets. Other products that are involved in the cementation procedure—such as hemostatics, cleaners, bonding agents, and primers—can affect curing times, so clinicians must be aware of how they may affect the cement. For example, Dr Goodchild says, in some cases the use of a bonding agent with a resin cement can accelerate setting time. In that situation, a clinician has to make sure they remove excess cement quicker than if no bonding agent is used.
Make things routine
Having a routine for addressing—or avoiding—excess cement can make the entire process much simpler. This starts with knowing the procedure and having a set plan for successful cement removal.
“Whether it is a porcelain veneer, posterior e.Max porcelain onlay or a zirconia crown being cemented, it is important for the clinician have a routine for proper resin cement clean up,” says Wynn Okuda, DMD, president of the Pan Pacific Dental Academy, and private practitioner in Honolulu and Oahu, Hawaii.
There are several tried-and-true routines to choose from. Clinicians can decide to clean any excess cement prior to curing, or tack cure and then clean up the excess. If a clinician decides to clean up before curing the resin, care should be taken to ensure the restoration is not moved or displaced during the cleaning process. Alternatively, the restoration can be seated and tack cured to a gel phase, but it’s a timing game: Attack the cement too soon when it’s only partially cured and you risk pulling it out and exposing the margins. Wait too long and the resin will overcure and leave the gel phase, making cleanup a much longer process.
Dr Okuda prefers the second approach, and likes to begin cleanup before final cure. His routine starts with placing luting resin, and then placing the restoration on the tooth so that the margin is full adapted. He then tack cures the facial and lingual sides for 2 seconds each. Subsequently, he flosses the contacts, and gently removes most, but not all, of the resin cement from the margin. After final curing, he seals the margin with glycerin and light cures it again, before finally removing any remaining excess with a composite scaler and carbide finishing burs from Komet USA. A final floss of the contacts finishes the procedure.
“Because I take steps to remove most of the resin prior to full cure, it makes cleaning up much faster,” he says.
Sarah Jebreil, DDS, a cosmetic dentist practicing in Newport Beach, California, also prefers this approach. “It’s nice to get the majority of the cement off before doing the final cure,” she says. “I always like to floss and clean up before going for the full cure.”
Choosing a cement that has a long gel phase or wider tack cure window can also help practitioners avoid difficult cleanup. For example, Calibra Universal (Dentsply Sirona), allows for either self-curing or light curing, and offers a wide tack cure window of up to 10 seconds. The cement also has a 45-second extended gel phase when light cured to remove excess cement, allowing dentists to remove that excess material before it hardens. This time ensures that the resin can be removed easily, lowering the risk of postoperative sensitivity that can occur from bur usage to remove excess cement after it has hardened.
Another popular option, TheraCem from BISCO, has been cited as ideal for implant crowns due to its simple delivery system and easy cleanup. Results from a survey by Catapult Education found that 82% of evaluators gave the self-adhesive, dual-cure resin cement, a top score for ease in cleanup.1
Regardless of which cement you choose, make sure you know how it functions and reacts.
“You shouldn’t need special tools for excess cement cleanup with indirect restorations,” Dr Goodchild says. “An explorer and floss are all I usually ever use. However, if you don’t know how a cement works, and you don’t clean it up before it sets and becomes strong, well then it will be a big problem.”
The most basic way to simplify cement cleanup? Avoid excess cement cleanup as much as possible. Many cement problems aren’t caused by the material, but rather by user error, so preparation becomes a critical factor. By planning ahead, clinicians can ensure they won’t get stymied by curing or set times. Matching the cement to the right type of substrate for a specific clinical situation can also mitigate cementation challenges.
“I try to plan ahead,” Dr Goodchild says. “I don’t subscribe to an if/then approach to cementation. For example, if I’m cementing a zirconia crown then I don’t always reach for glass ionomer. If I know I’ll be making a crown in a hard-to-reach area where isolation is tricky, I may alter the prep to create more retention so the strength of resin isn’t necessary. But you have to be prepared for this before going in.”
Dr Goodchild says that treatment planning is the best way to ensure there are fewer mistakes with cementation.
“The point is, one of the ways we can set ourselves up for success with cementation is to think about what materials we want to use up-front,” Dr Goodchild says. “I’m always thinking about how I should prep the case so I can get the impression, make a good provisional and then easily and successfully definitively cement it. Sometimes I call an audible and change my mind, but the concept of planning is essential and this process begins when we treatment plan the case.”
1. Griffin, J. Achieving consistency and easy cleanup with TheraCem. Dental Products ReportⓇ. 2019;2(13): 26-27. https://www.bisco.com/assets/1/7/TheraCem_Catapult_Review.pdf