Terri Lively

Supporting a Crown: Building Up Your Patient's Core. Photo courtesy of sujit/stock.adobe.com. 

Your patient’s core buildup replaces tooth structure under the crown where no one will see it. However, even though it’s underneath the crown, the composition of the core buildup material could influence the restoration outcome.

Core buildups used to be made of amalgam. Today, dental composite resins and resin-modified glass ionomers tend to occupy the space under the crown. However, there are any number of types of composite resin that you could use, and even some that are specifically designed to support a crown. So, how do you know what to choose? We look at the materials available and what features you should look for to support a crown.

Research Suggests the Stronger the Better

Studies suggest that core buildup materials should mimic tooth structure regarding hardness and resistance to fracture. Other properties essential in core buildup materials are that they are strong enough to withstand multi-directional chewing forces exerted upon them under the crown and should be able to handle the crown preparation process with a rotary cutting instrument. Per 

, the best resin materials for use with posts are those with high filler content because they help “enhance fracture thresholds of teeth.”

, strength is one of the most important criteria to consider when choosing a direct core buildup material; the stronger, the better. Since few studies had compared the strength of core materials, the journal’s study compared the mean compressive strength, diametral tensile strength, flexural strength, and elastic modulus. The researchers compared a few composites for strength, including visible light-cured composite, polyacid modified composite, resin-modified glass ionomer, and high copper amalgam and silver cement. They observed significant differences in compressive, diametral tensile, and flexural strength, with visible light-cured composite coming out on top in the study. The researchers determined that when dentists use more substantial materials for core buildups, they resist deformation and fracture, provide more excellent stability, and distribute stress more equitably. They concluded that more substantial core buildup materials increased the probability of clinical success.

 performed an in-vitro comparative study of core buildup resin composites for flexural properties. They chose core buildup resin composites that were dual-, light-, or self-cured to compare against conventional light-cure composites (from 3M ESPE, Dentsply, DMG, GC, Ivoclar-Vivadent, Kuraray, Septodont, Ultradent, and VOCO). The researchers discovered that the light-curing on a dual-cure core buildup material significantly influenced flexural modulus but not flexural strength. Their results also indicated significant differences between the types of core buildup materials regarding flexural modulus and flexural strength. The highest flexural modulus was seen in light-cure resin composites but identified no clear winner for flexural strength. They also saw a linear correlation between inorganic fillers content for flexural modulus but not flexural strength. The researchers concluded that highly filled, light-cured materials were the “most appropriate” for core buildups. They also determined that self-and dual-cure core buildup materials with lower inorganic filler content were inappropriate for replacing dentin in significant tissue loss cases. They also recommend using inorganic filler content as an easier way to decide which materials to use for core buildups.

Practical Dentistry Takes a Different View on Material Choices

Jason Goodchild, DMD, Vice President of Clinical Affairs for Premier Dental Products Company, describes a core buildup as a direct restoration designed to be part of the crown preparation. When it comes to materials for core buildups, Dr Goodchild chooses based on the appropriate characteristic for the case. Like the studies suggest, strength might be the most important characteristic for the core buildup material in some cases, but handling might be the most critical for others.

For example, many core buildups occur after a root canal treatment. So, if the core buildup follows a root canal and goes down into the root with a post, Dr Goodchild might use a dual-cure composite material. That way, he explains, if the light cannot get down deep enough to cure the material, the chemical cure component of the dual-cure composite can handle it for him. However, if he gets an endodontically treated tooth with concerted access that leaves a small hole, Dr Goodchild might use regular light-cured composite as he does for direct restorations.

“What core build-up material am I going to use?There are a lot of unknowns until you see the situation clinically,” Dr Goodchild says.

Dr Goodchild says that dentists can often use any material they want depending on what they are looking at size- and depth-wise. For small to moderate preparations, he likes SureFil

 (Dentsply Sirona) because it adapts easily to the cavity and is highly radiopaque.

However, Dr Goodchild thinks there are many other core buildup materials that are good, too, especially when the hole is more extensive. For example, he says Premier’s CompCore

 AF Dual-Cure performs well for compressive and tensile strength, and also has good radiopacity. Plus, it cuts like a natural tooth. However, he also recently used a flowable for a core buildup because the replacement area wasn’t that extensive, and the material was already handy in the operatory.

Other manufacturers have materials that are specifically for core build ups, too. BISCO’s Core buildup materials include Light-Core

, a light cured core build up composite, Core-Flo

 DC, a dual-cured, radiopaque composite with an auto-mix syringe, and Core-Flo

 DC Lite, which is designed to cement posts and buildup the core in one application. VOCO has Rebilda

 DC Core Buildup Composite, a flowable adhesive composite with Fluoride release, and Grandio

 Core Dual Cure, which is a dual-cure buildup material marketed as a luting agent for root posts in addition to buildup material. Denstply Caulk has Fluorocore 2+ Dual Cure Core Build-up Material, which also is fluoride releasing and dual cure.

When it comes to the ideal characteristics of the materials, Dr Goodchild values more than only strength. In addition, he likes ease of placement so he can get the material into the areas to bond with the remaining tooth structure, radiopacity so he can see where the buildup material is on x-rays, and fluoride-releasing to help prevent future caries in the restoration. The most significant factor in Dr Goodchild’s material choice, however, is the ability to place the material.

“We can’t forget that the basic crown & bridge principles will still apply, and you must have crown margins on teeth. So, it’s great to have buildup materials that are strong, absolutely, all day, every day. But I think we can have strong at the expense of handling, and the buildup material still needs to handle well,” Dr Goodchild explains. “So, to me, strength is one of the components, but not the whole thing.”

What To Remember about Supporting a Crown with a Core Buildup

Whatever you choose for materials, Dr Goodchild says it is essential to know how to use them quickly and effectively. Since crowns are a standard procedure and a significant source of revenue for the practice, the materials you choose should also increase efficiency. That’s why Dr Goodchild says that dual-cure materials are excellent for core buildups because you can fill up the whole cavity and prep with it or do the entire core in 1 step.

“I always say that in dentistry, we get good at doing things the same way and not by doing them differently every single time,” Dr Goodchild says. “I do the same kind of crown preps because I know how to do them very well.”

However, Dr Goodchild isn’t saying that there is only 1 way to replace the missing tooth structure to support a crown. Instead, he feels that every dentist probably has a few different ways of doing things because they have delivered consistent positive results and clinicians generally use the same materials and techniques in the various approaches.

Dr Goodchild also likes to “match up the rights.” Matching up the rights refers to using the right materials for the right clinical indication on the right patient. For example, maybe you want fluoride for this patient. On the other hand, perhaps you need to go deep into the tooth, so you want dual-cure, or you need to ensure that the build-up shows up on radiograph, so you emphasize radiopacity.

“Matching up all the rights lets you use those materials to their fullest potential,” Dr Goodchild says. “

Dr Goodchild thinks that it is critical to take a back-to-basics approach on technique. Every dentist has removed a crown and seen work where compromises were made.In some cases, the crown prep might not be what you consider acceptable, or it was not reduced enough. Maybe the finish lines are hard to read, or they’re ending on restorative material instead of the tooth.

“In 2021, we have unbelievable materials that do a lot of things for us. We have materials that are very forgiving that we can place in all different environments,” Dr Goodchild says. “But it doesn’t mean we can shortcut basic principles.”

Panitiwat P, Salimee P. Effect of different composite core materials on fracture resistance of endodontically treated teeth restored with FRC posts. J Appl O

ral Sci. 2017;25(2):203-210. doi:10.1590/1678-77572016-0306

Kumar G, Shivrayan A. Comparative study of mechanical properties of direct core buildup materials. 

. 2015;6(1):16-20. doi:10.4103/0976-237X.149285

L. Spinhayer, A.T.B. Bui, J.G. Leprince & C.M.F. Hardy (2020) Core buildup resin composites: an in-vitro comparative study, Biomaterial Investigations in Dentistry, 7:1, 159-166, DOI: 10.1080/26415275.2020.1838283

Articles

We look at what matters most when selecting materials to replace lost tooth structure and support a crown. 

Supporting a Crown: Building Up Your Patient’s Core

Polish: Making Your Restorations Shine. Photo courtesy of zlikovec/stock.adobe.com. 

Polishing a restoration creates a smooth surface that simulates the glossy look of the patient's enamel. As the final step, polishing serves as your last chance to optimize the success of the restoration. Therefore, we look at the advantages of polishing and the different materials suitable for various restorative goals.

There are quite a few advantages to finishing and polishing in addition to looking good. Polishing requires clinicians to smooth the cavosurface margins and reconstruct the functional anatomy of the restored tooth, providing an imperceptible restorative margin free from voids. The glossy surface of a polished restoration also creates a plaque-resistant environment for the patient, making it easier for them to clean and contributes to the excellent health of the patients' gingival tissues. These factors lead to increased longevity of the restoration.

In other words, polishing is the last step but a no less crucial one than all that came before it. If you skimp here, you could end up with poor implications for oral health, restorative function, and esthetics, which range from biomaterial accumulation, irritated gums, and surface staining.

Clinicians polish right after contouring and finishing. It usually starts with pre-polish, where the dentist removes the scratches that might have occurred during finishing. Dentists then establish a smooth surface. Then, the clinician goes back to "super-polish" the restoration. This third step is where clinicians achieve the enamel-like luster that everyone wants.

However, all resin composites do not produce the same surface roughness. Different variables affect this factor, some of which come from the materials themselves and some from external agents. Internal factors include the type of material and fillers and the fillers' shape, size, and distribution. Also, the polymerization, resin makeup, and bond durability between the filler and the matrix affect the success. The external factors originate in the clinician's finishing and polishing technique. These include the flexibility and shape of the polishing tools, which abrasive they use and its related hardness, and the clinician's polishing skill.

Unlike the finishing phase, which establishes the restoration's form and texture, polishing is about getting the luster right, to the point that the patient doesn't notice the repair in their mouth. Practical Procedures in Aesthetic Dentistry suggests facilitating some "dark polymerization” by waiting 10-15 minutes after light curing to polish. In addition to general observation of the patient's other teeth and those related esthetics, they recommend tungsten carbide burs to develop the macro-texture and proximal burs for gingival and proximal finishing.

Polishing Material Types Have Different Strengths and Uses

What you use to polish composite restorations has a lot to do with restoring the tooth. Jeff Lineberry, DDS, FAGD, AAACD uses different systems and pastes depending on what function the tooth surface will serve the patient best.

"It's a whole different ball game in the facial anterior surface than an occlusal area," Dr Lineberry agrees. "The wear and tear that you get on a facial surface are different than the occlusal surface, so it's not subject to the same conditions."

One of the most popular abrasive materials for direct and indirect restorative dentistry is diamond polishing paste. Studies suggest that these pastes are successful in decreasing biofilm accumulation and providing excellent surface properties for the restoration.

In her private practice in Newport Beach, CA, Sarah Jebreil, DDS, AAACD, likes to use diamond paste on the anterior restorations. Dr Lineberry uses it there but will sometimes use the diamond-impregnated paste on the posterior too. However, Dr Lineberry says that using diamond paste with a felt polisher in posterior restorations has more to do with feel than looks.

"It will take it to a level of polish that patients will say it feels like their tooth," Dr Lineberry explains.

Dr Jebreil says her posterior work is rarely a direct composite filling and is more likely to be an onlay or an inlay, which she polishes with regular polishing compound. 

"I like to use the points and cups. In the posterior, I finish it primarily with the finishing burs, my interproximal burs, and then working to the fine point balls bur polishers, and then go over it to polish it," Dr Jebreil explains. "When you do that, you see if the rubber cup is getting stuck in a void. Then, you can remove it and refinish it."

For a Class IV or a MIFL composite restoration, Dr Lineberry likes to use discs, from coarse to fine. Then, he will use a polish and buffer with a diamond enhanced paste.

However, in some cases, dentists can use a liquid polish. Some studies suggest liquid polish could help dentists achieve a perfect marginal seal. Applying a thick layer of a flowable resin with no filler to the cavosurface margins of the finished restoration can penetrate the micro defects and marginal gaps. The capillary action seals them and improves the marginal seal. One study suggests that the resin could also repair the pores and structural defects that occur during finishing and polishing.

In Dr Jebreil's experience, she doesn't like to use lacquer unless it's on a provisional. While she likes how liquid polish can seal porous acrylic materials, it wears away and stains over time. Liquid varnish also doesn't allow clinicians to fix voids when they should. Furthermore, if you put lacquer on a gap rather than repairing it, the lacquer will wear away, and the rough patches underneath will still be there. Then, the restoration gets bacteria in it, which can lead to recurrent caries. Also, restorations can have pits that look black as they age, which she wants to avoid.

"It's like the filling has a cavity in it, and it's because the restoration wasn't finished and polished properly," Dr Jebreil says. "For the long-term, you are better off polishing the restoration."

"As much as we would love to have a clear coat polish in the mouth like they put on cars, we don't have anything like that. Ultimately, that clear coating wears away. If you have a polished surface, then you have it, and it's not going to change," Dr Lineberry agrees. "I love clear sealers for provisionals. It works great for the final finish on provisionals."

What Dentists Should Remember about Polishing

Dr Jebreil thinks that clinicians should try many different polishing systems to find the one that works best in their hands. She likes the white cups and the pink and white cups. She also likes the goat hair polishing brushes because they make less of a mess and work well in her hands. 

"But maybe someone else likes something different. So, there are so many different products out there. Try a couple of different things and see what works, and you can mix and match, too, like 1 coarse from 1 company and 1 fine from another company," Dr Jebreil says. "You have to make your own formula." 

Dr Lineberry thinks clinicians should remember that polishing sets the stage for a longer-lasting restoration. When dentists polish away that flash, they reduce surface stains and discoloration. They also reduce plaque accumulation around those rough areas.

"It's worth the steps. Take the time and polish," Dr Lineberry says. "Your composite resin restorations will survive longer and look better if you do your proper finishing or polishing upfront."

Walls AT. Composite finishing and polishing. Pocket Dentistry. Published February 11, 2020. Accessed November 5, 2021. https://pocketdentistry.com/composite-finishing-and-polishing/

Koirala, Sushil. (2020). Direct Composite Resin Finishing & Polishing Technique. 1. 18-22. Published August 2020. Accessed October 25, 2021. https://www.researchgate.net/publication/343629191_Direct_Composite_Resin_Finishing_Polishing_Technique 

Silva JP, Coelho A, Paula A, et al. The Influence of Irrigation during the Finishing and Polishing of Composite Resin Restorations—A Systematic Review of In Vitro Studies. mdpi.com. Published March 29, 2021. Accessed October 25, 2021. Materials-14-01675.pdf. 

Banerji, S. and Mehta, S.B. (2017). The Finishing and Polishing of Resin Composite Restorations. In Practical Procedures in Aesthetic Dentistry (eds S. Banerji, S.B. Mehta and C.C. Ho). https://doi.org/10.1002/9781119324911.ch5.6

Kurt A, Cilingir A, Bilmenoglu C, Topcuoglu N, Kulekci G. Effect of different polishing techniques for composite resin materials on surface properties and bacterial biofilm formation. J Dent. 2019;90:103199. doi:10.1016/j.jdent.2019.103199

Chour RG, Moda A, Arora A, Arafath MY, Shetty VK, Rishal Y. Comparative evaluation of effect of different polishing systems on surface roughness of composite resin: An in vitro study. J Int Soc Prev Community Dent. 2016;6(Suppl 2):S166-S170. doi:10.4103/2231-0762.189761

URQUÍA, M. C.; BRASCA, N.; GIRARDI, M.; BONNIN, C.; RÍOS, A.; GIRARDI, I.; CHÁVEZ, L. J. & DELGADO, A. Influence of surface sealants on microleakage in composite restorations. Int. J. Odontostomat., 11(4)

Polishing is the last chance you have to optimize the success of your restoration. Therefore, we look at the advantages of polishing and the different materials suitable for various goals.  

Polish: Making Your Restorations Shine 

What is MDP and Why is it an MVP for Bonding? Photo courtesy of The Cheroke/stock.adobe.com. 

When it comes to adhesive systems, many universal adhesives have incorporated methacryloyloxydecyl dihydrogen phosphate (MDP) into their primer formulation. Many clinicians know that MDP in the primer enables bonding to metal and zirconia, but might not know that MDP also forms a chemical bond with calcium phosphate, the mineral phase in tooth structure. Let’s take a closer look at what MDP is and why it does such an excellent job in bonding primers for restorative dentistry.

In 1981, Kuraray introduced the first MDP monomer. From the start, MDP demonstrated effective bonding to enamel, dentin, and metal alloys.

MDP can also establish an intense and stable chemical interaction with teeth. As a functional monomer, MDP also has acidic molecules that can do a few different things, like:

Provide opportunity for adhesives to have chemical interactions with the tooth

Functional monomers have 2 functional groups, 1 that demineralizes the tooth and another that can polymerize. Nathaniel Lawson, DMD, PhD, Associate Professor and Director, Division of Biomaterials UAB School of Dentistry, says MDP is a molecule that has a phosphate-based functional group on one end and a methacrylate-based functional group on the other.

Dr Lawson says MDP can be used for bonding to tooth structure or zirconia. When bonding to the tooth, Dr Lawson says the MDP has the 2 functions of partially demineralizing the tooth and also bonding with calcium in the tooth. MDP is an acidic monomer, similar to other acidic monomers used in self-etch adhesives. Dr Lawson says that acidic monomers partially solubilize the smear layer and remove some of the mineral content of enamel or dentin.

Forming a chemical bond with hydroxyapatite is not business as usual for bonding agents. Many bonding agents infiltrate small surface irregularities in the patient’s enamel or dentin creating a micro-mechanical bond, but can’t react chemically with the tooth surface. Using a universal bonding agent with MDP, clinicians can achieve both a micromechanical and chemical bond.

“The unique aspect of MDP is that it can also bond to the calcium in mineral content of tooth, similar to the bond between calcium and the polyacrylic acid in MDP,” Dr Lawson says.

MDP also has the potential to improve the long-term seal and durability of the bond. In adhesive systems, how the bonding agent interacts with the collagen is critical. The deterioration that can occur with the collagen fibrils in the hybrid layer is what causes the problems with dentin bonding over the long term. The functional monomers like MDP have chemical properties that create the high-strength bond with dentin.

The same cannot be said of components of other adhesive materials. A common ingredient in dentin bonding agents is 2-hydroxyethyl methyl methacrylate (HEMA) because it is hydrophilic. In other words, HEMA allows the bonding agent to bond and polymerize in the presence of moisture found in enamel and dentin. However, HEMA's high hydrophilicity also makes it prone to water sorption, which can degrade the collagen fibers bond over time, which decreases bond strength and an increase the risk of marginal staining and recurrent caries.

By contrast, MDP improves shear bond strength and the stability of the margin for restorations, which increases the durability. First, the prevention of water sorption avoids a gradual breakdown of the bonding layer over time. Also, the absence of HEMA helps to preclude moisture from adhering to collagen fibers in the hybrid layer. Moreover, with MDP there is no degradation of those fibers in the hybrid layer either.

suggests that MDP can produce and acid-base resistant zone on the adhesive surface, increasing the response to acid-base challenges. This interface response creates a stable adhesion over time. However, the authors also recommend using a scrubbing technique on dental substrates to promote solvent evaporation and improve the monomers infiltration into the smear layer to create a stable bond between the adhesive and the substrate. Also, they say that giving MDP time to hybridize and form the chemical bond with tooth structure improves bond stability.

However, in addition to tooth structure, MDP also bonds to zirconia. Having a universal adhesive system with MDP eliminates the need for practices to have a stand-alone or zirconia primer in their inventory. What makes it possible is MDP’s 2 functional molecular groups: the phosphate containing group that bonds with zirconia and the methacrylate end that crosslinks with methacrylate in resin cements, Dr Lawson explains.

“When bonding to zirconia, the phosphate-based functional group bonds to zirconia and the methacrylate end bonds to resin cements. So, MDP are used in primers or universal adhesives that are applied to zirconia crowns before bonding,” Dr Lawson explains.

MDP-based products produce a high bond strength and chemical affinity. Per research in 

, using MDP primers increased bond strength over those that didn’t use primers. Moreover, when combined with air abrasion techniques, the researchers had the best bond strengths, which they attribute to enhanced surface wettability from the air abrasion technique and the increased bond strength created by primers containing MDP.

 Research in Operative Dentistry reached similar conclusions in 2020, suggesting that MDP-containing silane coupling agent used alone or with universal adhesive solution created durable bonding to zirconia.

MDP has been around now for 4 decades. Over this time, it has found its way into most of the universal adhesive primers available on the market today, mostly because it creates a strong and reliable bond with tooth structure, metal alloys, and zirconia. Not only does it stop the deterioration of collagen fibrils in the hybrid layer of natural dentition which degrades bond strength over time, but it also forms the same chemical bonds with the chemical makeup of zirconia. These bond strengths are more intense and longer lasting that any of the other materials or techniques used in adhesive systems. For these reasons, you might find that your universal adhesive system containing MDP in the primer is the MVP for your practice, and your restorative outcomes.


MDP Monomer - Kuraray Dental. Kuraray Dental. Accessed October 8, 2021. https://kuraraydental.com/clearfil/key-technologies/mdp-monomer/. 

Carrilho E, Cardoso M, Marqes Ferreria M, Miguel Marto C, Paula A, Sofia Coelho A. 

10-MDP Based Dental Adhesives: Adhesive Interface Characterization And Adhesive Stability—A Systematic Review

. Accessed October 8, 2021 .mdpi.com; 2019:1-2. https://www.mdpi.com/1996-1944/12/5/790/pdf. 

.Accessed October 8, 2021 mdpi.com; 2019:1-2. https://www.mdpi.com/1996-1944/12/5/790/pdf. 

. Accessed October 8, 2021 mdpi.com; 2019:1-2. https://www.mdpi.com/1996-1944/12/5/790/pdf.

. Accessed October 8, 2021. mdpi.com; 2019:1-2. https://www.mdpi.com/1996-1944/12/5/790/pdf.

Yue, X., Hou, X., Gao, J., Bao, P., & Shen, J. 

Effects of MDP‑based primers on shear bond strength between resin cement and zirconia.

 Experimental and Therapeutic Medicine, Spandidos-publications.com 2019 October 8, 2021.; 3564-3572. https://doi.org/10.3892/etm.2019.7382

MF Gutierrez, J Perdigão, P Malaquias, AM Cardenas, F Siqueira, V Hass, A Reis, AD Loguercio; Effect of Methacryloyloxydecyl Dihydrogen Phosphate–Containing Silane and Adhesive Used Alone or in Combination on the Bond Strength and Chemical Interaction With Zirconia Ceramics Under Thermal Aging. Accessed October 8, 2021. 

 1 September 2020; 45 (5): 516–527. doi: https://doi.org/10.2341/18-093-L 

Many of today’s universal adhesives have moved to MDP in their material makeup. We find out why and what you need to know about it for your restorative technique and outcomes.

What Is MDP and Why is it an MVP for Bonding?

Different Ways to Protect Dental Pulp. Photo by Alexandr Mitiuc/stock.adobe.com. 

Protecting the pulp is essential when it is exposed in preparations to prevent pain, infection, and the eventual loss of the tooth. Pulp capping can help, which involves sealing materials over the exposure to protect the pulp. There are many options for pulp capping in restorations. We take a closer look at some of them and the newer players in the field that can serve this essential function in your restorations.

There are a few ideal qualities for pulp capping materials. No matter which material you choose for protecting the pulp, the 

Journal of Pharmaceutical Sciences and Research

 (JPSR) suggests it should be bactericidal or bacteriostatic, sterile, and radiopaque. Also, it should also:

Release fluoride to prevent secondary decay

 says some common materials pulp capping materials include:

 in 2009 has the following advice for successful pulp capping:

Start by avoiding pulp exposure in your preparation, even if it means residual caries remain behind, to increase the chances of tooth survival.

Control bleeding with water, saline, or sodium hypochlorite as they will be gentle with exposed pulp, and sodium hypochlorite can disinfect the area.

Avoid Glass Ionomers and Resin-Modified Glass Ionomers, and adhesives for pulp capping because of their poor performance.*

Consider using MTA as it produces comparative results to Calcium Hydroxide.

Use Calcium Hydroxide for direct pulp capping because of its long track record of success.

Seal the restoration well right after pulp capping to protect against leakage and bacterial contamination.

*An in vitro study in 2018 demonstrated that light curing pulp capping materials caused deformation of pulpal dentin and increased pulpal temperature in large mesio-occlusal-distal (MOD) bur preparations with 1mm of dentin remaining at the pulp floor. There was no difference between the 3 materials for preventing the pulpal temperature increases.

The Latest and Greatest in Pulp Protection

However, much has changed in the materials for pulp capping over the last decade or so. While Calcium Hydroxide remains effective, other materials might challenge its gold-standard status and last longer. Tim Bizga, DDS, FAGD, a private practice dentist outside of Cleveland and lecturer for the dental industry likes using different materials in his liners for pulp protection. He is a big fan of BISCO’s Thera line products that use calcium silicates in their formulation.

 is a dual-cured product that releases calcium and fluoride after placement. The self-adhesive base or liner creates an alkaline PH, which is designed to promote pulp vitality. In the Bisdent Globe newsletter, one doctor describes it as forming “a protective barrier that insulates the pulp.”

One of the other products in BISCO’s line is the TheraCal LC

, a light cured flowable resin-modified calcium silicate liner. It contains MTA and is designed to be a pulp cap for direct and indirect restorations.

MTA is made up of tricalcic silicate, tricalcic aluminate, and bismuth oxide and is a biocompatible material. MTA is made up of fine-sized particles that are hydrophilic and harden in the presence of dampness or blood. MTA is also radiopaque and harder to infiltrate than other materials used for the same purpose. In addition, MTA hardens slower than other materials (in a range of about 2 hours and 45 minutes to 4 hours), which reduces the tension internally on the restoration. Moreover, MTA has a reputation for superior sealing properties, which makes it excellent for many purposes, including protecting exposed pulp in preparations.

Dr Bizga likes how the BISCO materials with MTA are light-curable, which means you can set the material immediately. Most MTA materials require a couple of hours to set, which doesn’t work for clinicians in a busy practice setting.

“What is really great about BISCO’s MTA materials is they release a ton of calcium, and they tend to skew toward the pH Alkaline scale. So, when you put them in deep dentin or an area where you’re concerned that the pulp will be irritated, this has unique chemistry that helps,” Dr Bizga says.

 suggests that MTA and TheraCal support the formation of tertiary Dentin, which is reparative dentin. However, the authors also suggest that because TheraCal has an easier application, improved sealing ability, and allows for permanent restoration placement in the same appointment, TheraCal is recommended as an alternative to MTA.

 Dr Bizga likes how it counteracts decay and creates a pH alkaline environment inhospitable to bacteria.

“You’re killing the bacteria with an alkaline environment, which allows the body to self-repair and heal,” Dr Bizga explains, adding that these products begin to cross over into biodynamic materials.

Some clinicians would rather use a glass ionomer, and Dr Bizga thinks that is great for many cases. However, in deep preparations, the way glass ionomers set can be an irritant to pulp. This situation pushes restorative dentists toward alkaline pulpal protectants.

“If they are alkaline, the pH scales differences are more calming to the tooth than irritating. It’s the thought process about where you are and how it changes the materials you use,” Dr Bizga says.

One of the other things Dr Bizga likes about these liners is that it replaces the 2-step process required when using calcium hydroxide covered by glass ionomer. Depending on the patient or the productivity targets, many clinicians may not want a 2-step liner process. He thinks that all of the calcium silicates liners are quicker to place and have the same properties as the historical liners that came before. What you choose depends on the case and what you are trying to do, and even whether to line it at all.

“It’s clinician’s choice,” Dr Bizga says. “I have been in rooms with KOLs who say your restoration is only as strong as your weakest link. With that thinking, clinicians might think, ‘Why am I putting on a weakly-bonded material at the bottom of the restoration that could potentially undermine it?’”

Dr Bizga says there are 2 schools of thought on lining. Some clinicians describe it as a coverup for poor bonding technique; others see it as a way to add a material that can help the tooth as much as possible with ion release in the area, even if it requires another step. Dr Bizga uses a case-by-case basis for his liner placement, seeing them as a tool for specific restorations rather than a typical step in all his restorative treatments.

“I make a judgment call based on what I see and what I think is going to be best to help the tooth and its life cycle,” Dr Bizga says. “It’s a great thing to have in your repertoire and the new lines available make placing them more convenient. And the science supports that they work.”

Getting the Most Protection with Your Liners

When it comes to placing liners, in addition to choosing the cases that require them, Dr Bizga has a few tips. Liners are best used sparingly, half-millimeter increments, as specified in the directions. The exception are bases because they are intended to go in thicker. Also, Dr. Bizga likes to disinfect the Dentin before placing any liner material down. Sometimes he uses a four percent chlorohexidine solution first; others he uses FiteBac® Antimicrobial Cavity Cleanser, which is a quaternary ammonium linked to polymerizable silane.

“It makes sense to me,” Dr Bizga says about disinfecting the tooth before placing a liner. “Any time you are applying some sort of paint, adhesive, or primer, the directions always say to get the substrate as clean as possible. While the bur does part of it, there is a microscopic level. This category helps make those protections better because if you are cleaning up the surface and then sealing that clean surface up, it gives the liner an even better chance of doing its job.”

Chandrasekhar H, Sharma S. Efficient Agents for Pulp Protection: A Review. Jpsr.pharmainfo.in. Published 2016. Accessed October 12, 2021.https://www.jpsr.pharmainfo.in/Documents/Volumes/vol8Issue11/jpsr081116014.pdf.

Hilton TJ. Keys to clinical success with pulp capping: a review of the literature. 

. 2009;34(5):615-625. doi:10.2341/09-132-0

CJ Soares, MS Ferreira, AA Bicalho, M de Paula Rodrigues, SSL Braga, A Versluis; 

Effect of Light Activation of Pulp-Capping Materials and Resin Composite on Dentin Deformation and the Pulp Temperature Change.

 2018; 43 (1): 71–80. doi: https://doi.org/10.2341/16-325-L Accessed October 12, 2021.

Theracal LC—Over 5 Million Restoration Later: Are You Getting The Most Of It?

. 1st ed. Chicago: BISCO; 2015:3. Accessed October 12, 2021. https://www.bisco.com/assets/1/7/MC-51160BD.pdf.

Casella G, Ferlito S. The use of mineral trioxide aggregate in endodontics. 

Menon NP, Varma BR, Janardhanan S, Kumaran P, Xavier AM, Govinda BS. Clinical and radiographic comparison of indirect pulp treatment using light-cured calcium silicate and mineral trioxide aggregate in primary molars: A randomized clinical trial. 

. 2016;7(4):475-480. doi:10.4103/0976-237X.194109

We explain the options for lining cavity preps to protect the tooth structure and the advantages and disadvantages of each. 

Different Ways to Protect Dental Pulp

Hitting the Hygiene Gas Pedal. Photo courtesy of WavebreakMediaMicro/stock.adobe.com.

The hygiene department provides preventative oral care for their patients. However, they also do a lot more than that, too. All these tasks take time, and take time away from working with patients. We share products, practical tips and best practices that can help them manage their critical role in the dental practice with more efficiency and effectiveness, so hygienists can spend more time with their patients.

Tim Quirt, DDS, Vice President of Clinical Operations at Heartland Dental thinks technology is the foot on the gas pedal for the hygiene department to keep teams feeling engaged and happy with their work. Quirt says hygienists are doing more procedures than before, but often with the same time allotted for patient appointments.

“It’s time that we as an industry help hygienists by understanding that they have so much to do and finding ways to make that easier for them,” Dr Quirt says.

Mike Massotto, Founder and CEO of Staff Driven Dental and Dental Coaching on Demand, agrees the perception of hygiene as teeth scraping should change. While the prophy is part of hygiene, and what patients remember most, the total care hygienists provide is much more. He also advocates creating an optimum working environment where everyone feels accomplishment.

“When hygienists feel that they're winning, successful and happy, you're getting the most efficiency and effectiveness out of your hygiene team,” Massotto says.

Katrina Sanders, RDH, a practicing dental hygienist, dental hygiene educator, and an international speaker, says that changing patient perceptions about how hygienists serve them is also an important priority to increasing efficiency and effectiveness of the hygiene department. While hygienists understand the disease process, prevalence, and problems of periodontal disease, decay, and oral cancer, patients don’t. Patients sit in the chair thinking they are in good health and ask about whitening, but the hygienist knows they need more, Sanders says.

“Patients don't understand if your gums are bleeding, if you have a pimple on the side of your gum tissues or early decay where bacteria has literally eaten away at your enamel, the hardest substance in your body, if you smoke or have an elevated risk for human papillomavirus 16 or 18, you have an elevated risk for these diseases, and we're screening for them,” Sanders says. “Patient value in their oral health has been a big barrier in us feeling comfortable, even telling the patient they have a disease process.”

Ways to Hit the Gas on Efficiency and Effectiveness

So, how do we change these perceptions and create the optimum working environment for efficiency and effectiveness? It starts with planning.

Tina Clarke, RDH, instructor at Lane Community College, practicing clinician, continuing education speaker and industry speaker thinks planning ahead for the next day, or even a few days out, can help hygienists’ efficiency in the operatory. From getting organized with what treatments are lined up to ensuring that all the tools are sharp and ready for treatment, planning helps things run more smoothly for the hygienists’ schedule. Clarke compares it to using meal planning to reach nutrition goals.

“When we are trying to have a strong healthy diet, we do prep cooking and plan head for the store, right? Planning for our treatment for the week is similar. We see what patients are coming in and plan for them,” Clarke explains. “If you see in the chart that a patient has a high caries risk, the hygienist can ensure that the supplies are on hand to treat them for that.”

Clarke says having backup instruments on hand organized by type can also help.

“If you individually wrap them and organize them where the Gracey 13/14s are in one place and the extra universal scalers are in another, you can easily grab and go,” Clarke says.

For sharpening, Clarke does her instruments by hand, which she says isn’t for everyone. She says other hygienists like the PDT Gleason Guide™ or Hu-Friedy’s Sidekick®. She also likes the Hu-Friedy Diamond Sharpening Instrument Card because it’s thin, about the size of credit card so it’s easy to hold, and sharpens instruments in a few strokes. She also suggests hanging onto the old instruments even when replacements arrive.

“Brand new instruments are beautifully sharp, but they’re pretty wide and don’t always work well for all of our patients. Make sure you hold on to some of those thinner instruments that you can use for your patients who have really tight gum tissues. Don’t just automatically replace and have all brand-new instruments in there,” Clarke says.

In addition, Clarke likes ultrasonics and all the appropriate aerosol guides. She also says having a variety of ultrasonic insert tips makes a huge difference in operatory ergonomics. Moreover, dental loupes with a head light also support better ergonomics while delivering patient care.

“It makes such a difference,” Clarke says about her Q-Optics loupes. “I don’t know if I could ever live without them.”

Another helpful product are color-coded probes. Hu-Friedy has color-coded single-end Colorvue® Probes that have yellow tips to add contrast in the oral cavity.

“The yellow markings instead of silver and black markings are nice when you are working in a dark environment,” Clarke says.

Clarke says hygienists should also use that planning to control and manage their schedule, arranging for complexity and preparation. For example, if a patient is coming in who needs x-rays and appropriate assessment along with their usual treatment, hygienists can schedule them for an appropriate amount of time. However, she realizes this approach can present challenges.

“If you are also an employee that has other individuals looking to see if you are being productive financially, it can be a big challenge,” Clarke says about managing the schedule. “Hygienists should advocate for themselves in those situations that this scheduling is how production is going to go up. Really, you’re advocating for your patients and the health care your patients deserve.”

Alyssa Aberle, RDH, Executive Administrator for the Colorado Dental Hygienist Association,and hygienist for a community health center, says hygienists need assistants. Hygienists have efficiency challenges because they work alone. Forgetting or dropping equipment or needing something that isn’t in the room requires changes in personal protective equipment (PPE) and inhibits efficiency.

“It’s a lot of taking off gloves or switching barriers to get something from another room. Most of the problems could be alleviated if there were other people available,” Aberle says.

Another way to increase efficiency is to alleviate some tasks, like scheduling or room turnover, to free up hygienists for patient care.

“Having effective system in your office where each person has their role and knows where it fits in the timeline of an appointment can help things be more efficient,” Aberle explains.

Tools that free-up hygienists’ hands while working with patients are also valuable to efficiency, Aberle says. Trying to hold everything during the appointment contributes to poor ergonomic positioning, which leads to injury. Moreover, the high-volume evacuation (HVE) units hygienists have incorporated since the COVID-19 pandemic have exacerbated the problem. Aberle likes how the Purevac HVE (Dentsply Sirona) has a mirror on the end, alleviating the need to hold suction and a mirror. Aberle also likes DryShield® or IsoDry® (Zyris), which have a bite block with an isolation system that frees up hygienists’ hands. Aberle also started using Aerosol Assist, an HVE for aerosols that also has a saliva injector in the same device.

“It rests on the patient’s cheek. So, you’re getting fluids out of their mouth but also mitigating the aerosols and, again, not having to hold it with a hand that you need for something else,” Aberle says.

Hands-free charting options help efficiency, too, Aberle says. Whether using foot pedals or a headset with voice recognition, or the Florida Probe System that perio charts while probing, having instant charting makes a significant difference in clinician efficiency.

“Then you are not, seeing 3 numbers in your head and trying to remember them as you turn around and type them in, and then turning back around to reposition. It’s amazing how much extra time that takes,” Aberle says.

Dr Quirt also thinks investing in technology and digital processes that increase patient convenience has benefits for the hygienist. For example, if a patient is late and then has to fill out paper forms, the schedule is off already. Sending digital forms in advance can help.

Ensuring that the technology the hygienist wants to incorporate is compatible with practice management software is essential, Dr Quirt says, otherwise you are only creating more work for hygienists. For example, Heartland Dental supported offices use Dentrix (Henry Schein One), which has a Dentrix Periodontal Chart to capture periodontal measurements, but Dr Quirt says there are many products out there that can help with the hygiene team.

“Over the years, we have given them so much to do over the years, and all of it is extremely important. So, we need to continue to find ways to make it easier for them,” Dr Quirt says. “They have been a jack-of-all-trades for years and we have the technology out there to make it much easier so they can spend their time coaching their patients and getting the care they need, want, and desire.”

Sanders says that imagery can make a significant difference to build patient trust. However, hygienists need training on the camera to take clear photos and how to explain what they are seeing there. Sanders likes to ask patients what they see when she shows them an image of their oral cavity. Moreover, she wants hygienists not to make assumptions when patients say, “does my insurance cover this?” it doesn’t mean that finances are their only motivator. Patients might just want to know if its covered, she explains. As patient advocates, Sanders says hygienists should help motivate patients to change based upon their value system.

“So, when we use tools like an intra or extra oral camera, we have to onboard the patient in that process. When we use tools for perio, like the Florida Probe, we are giving patients the opportunity to ask, ‘what are those numbers? What does it mean?’ We have to bring patients into the equation,” Sanders says.

In addition, Sanders thinks that remembering how the pandemic changed things is essential. People are more aware that there are people with higher risk factors for certain conditions, and that being asymptomatic doesn’t mean you are not infected. Sanders thinks this experience presents an opportunity for the necessary change in hygiene perception. 


“Patients learned on the news to cover their mouth with a mask to protect themselves against this virus. So, they learned that the mouth is a portal to the rest of the body,” Sanders says. “A huge layer to this effort is that hygienists have to understand that society and our community as a whole are different.”

In addition to technology and tools, Massotto thinks practices should establish a collaborative, step-by-step hygiene system that creates consistent delivery of patient care and brands the practice.

“With a system, they get everything in, nothing is missed, and expectations are met,” Massotto says. “The doctor's happy; they're happy and less stressed. The day flows better.”

So, How Can Hygienists Get Their Feet on the Gas Pedal?

Aberle recognizes that these products and staff resources are not always available already. She recommends breaking down the numbers for the practice stakeholders to demonstrate how the investment will provide a return. Show how the efficiencies lead to comprehensive patient care in a shorter time, minimize downtime between appointments, and make it possible to provide more services in an appointment.

Ergonomics is another significant consideration for practice stakeholders. When hygienists have chronic pain, they need more time off and see fewer patients. Poor ergonomic conditions also lead to hygienists going part-time or developing long-term health issues that require surgery. It could also mean worker’s compensation claims.

“You are going to be able to increase your production and, if you look long term, a lot of these things help ergonomically, too,” Aberle says.

Joe Fogg, CEO of onDiem, an online temporary staffing agency, thinks additional staff can help increase production in the hygiene department. Fogg recommends bringing in supplemental professionals to help the practice maximize revenue.

“Most of our customers usually have an empty operatory,” said Fogg. “Consider hiring a temporary hygienist for the day to see routine prophy cases, and free up your regular staff hygienist to perform the higher-value more complex cases. Not only will this result in increased production, but you’ll also see the payoff in increased revenue both from the higher-value procedures and the additional referred procedures for future care.”

We share products, practical tips, and best practices that help hygienists manage their critical role in the dental practice with more efficiency and effectiveness, so they can spend more time with patients.   