Laura Dorr is the former executive editor of DPR's Modern Dental Network and a regular contributing author.

Laura Dorr

Image Credit: © nobeastsofierce / stock.adobe.com

The longevity of dental restorations has long been a concern for dentists and patients alike. And it should be: research shows that more than half of US restorations each year are performed to replace those that have failed

 primarily due to the bacteria that causes secondary caries.

 thrive in acidic environments and can quickly result in infection and restoration failure. Fortunately, antimicrobial substances have been incorporated into smart biomaterials to reduce the formation of the biofilm where bacteria flourish.

“Antimicrobial restorative materials can be…put on tooth preparations to address any remaining bacteria or [on] filling materials that prevent the attachment of bacterial plaque,” says Nathaniel Lawson, DMD, PhD, director of the Division of Biomaterials at the University of Alabama at Birmingham School of Dentistry. “The second application, an antibacterial filling material, is the newer concept.”

Triggered by internal and external stimuli, these substances deliver on-demand care and have surpassed antibiotics in popularity because their toxicity is lower, their shelf life longer, they cause less environmental harm, and offer superior control, location selection, and dosing options, thus reducing the risk of antibiotic resistance.

Although their goal is the same, these agents come in different varieties. According to Dr Lawson, “there are antimicrobial preventative materials, like those used in mouth rinses,” including “0.12% chlorhexidine, essential oils, and CPC [Cetylpyridinium chloride],” and others that “can be applied on tooth preparations…such as 2% chlorhexidine, silver diamine fluoride, GLUMA, or liners [calcium hydroxide and calcium silicate]…[and] a new antimicrobial composite [that] contains a quaternary ammonium compound.”

Antimicrobial agents can be classified into 3 categories: polymeric biocides, biocidal polymers, and biocide-releasing polymers. Polymeric biocides consist of amino, hydroxyl, or carboxyl units that are bound to a polymer backbone. They repel microbes and thus prevent their adhesion. Biocidal polymers contain cationic moieties (like quaternary ammonium compounds [QACs], phosphonium, guanidinium, and tertiary sulfonium) that kill microbes. Biocide-releasing polymers, as their name implies, discharge molecules into the oral microbiome that kill bacteria over time.

As Dr Lawson observes, many of these agents are added to preventative materials like chitosan, triclosan, polyquaternary ammonium salts, quaternary ammonium dimethacrylate, and furanone. More frequently, however, silver nanoparticle (NAg), 12-methacryloyloxydo-decylpyridinium bromide (MDPB), chlorhexidine digluconate (CHX), and QACs are used in them.

The efficacy of NAg, researchers say, stems from its ability to deactivate bacterial enzymes and alter the replication mechanism of bacterial DNA,

 whereas MDPB damages the cytoplasmic membrane of bacteria. MDPB was first used in CLEARFIL™ SE Protect (Kuraray Dental) and is now ubiquitous.

CHX kills cells by obstructing their membrane transport systems and causing their intracellular material to leak, thus preventing bacterial formation and reducing plaque accumulation around restorations. Commonly used in such mouthwash as 3M™ Peridex™ (chlorhexidine gluconate 0.12%) and in antibacterial solutions like Consepsis™ (2% chlorhexidine) from Ultradent, CHX is likewise found in numerous products outside the operatory.

QACs are said to be one of the most effective disinfectants in resin nanocomposites. Used as monomers or micro/nanofillers, they have 1 or more methacrylate functional groups. Those with longer chain links have higher antimicrobial activity. QACs have low cytotoxicity and offer strong long-term antimicrobial benefits without leaching.

One product making waves is Infinix™ from Nobio, the first FDA-cleared restorative material to contain nonreleasing, nonleaching QACs. These particles attract bacteria electrostatically and reduce enamel demineralization and secondary caries by 68%.

The Infinix product line includes both a universal and a flowable composite and a universal bonding system with primer and bond, all of which incorporate nonleaching, nonsoluble QACs.

There are 2 ways to deliver antimicrobials. The first is contact-killing and takes place at the treatment stage via disinfectants or etchants. The second is antimicrobial agent release, which involves inserting a leachable, polymerizable, or filler particle into a dental adhesive or resin and works over time.

Contact-killing agents are immobilized within the polymer structure and able to deliver long-lasting benefits without leaching. They prevent the growth of numerous pathogens known to cause caries, periodontal disease, and endodontic infection. These nonleaching materials reduce biofilm and microbial adhesion through physisorption and/or covalent conjugation.

 However, they are ineffective against planktonic bacteria and subject to biofouling, whereby they absorb dead bacterial cells and lose potency.

This approach allows not only for delivery of antimicrobial agents to a specific site, reducing the potential for antimicrobial resistance caused by less targeted approaches, but also for continued release of embedded compounds that kill bacteria over time. However, the rate and longevity of release are difficult to establish. Because the concentration of antimicrobial agents is low, their efficacy is reduced. NAg particles are the most commonly released antimicrobials, owing to their high biocompatibility and low toxicity.

These strategies are being developed to address the drawbacks of the other approaches. Antimicrobials that can be activated and function in different ways are more efficacious. Silver, for instance, has antibacterial, antiviral, and antifungal properties, its release is easy to control, and its long-term effect easy to sustain.

 NAg has also been combined with Quaternary ammonium methacrylates [QAMs] to kill bacteria on the material’s surface and away from it.

Contact-killing and chemical-releasing approaches employ bioactive, bioresponsive antimicrobials. Bioactives with metallic and nonmetallic fillers, CHX, other cationic monomers, including MDPB, and other QACs are incorporated into a carrier like a resin, filler, or coating, to deliver antimicrobials that work on contact and sometimes also have time-release capabilities.

Bioresponsive therapies offer long-term benefits. Once activated—by light, electrical or magnetic stimuli, pH changes, and bacterial or salivary enzymes—the biomaterial in the carrier (be it a resin, an adhesive, sealant, or nanocarrier) releases antimicrobials.

A third option, still under development, is an autonomous biomaterial that can respond to different stimulus and adapt itself to address them—essentially, the compound is completely integrated into the natural biological system.

Dental resins (composites, adhesives, and primers) are common vehicles for bioactive monomers,

 which can be linked inside the polymer chain or act as a leachable compound, both unpolymerized and polymerized.

 Antimicrobials in resins are effective against a wide range of gram-positive and gram-negative pathogens.

Biofilm-related infections have risen in tandem with the proliferation of resin-based materials.

 The rate of secondary infections with these materials have reached around 60%, making the integration of antimicrobial agents into resins a priority.

One study evaluating the efficacy against 

 of quaternary ammonium polyethyleneimine (PEI) nanoparticles in resins discovered that these nanoparticles had contact-killing effects that also lasted for at least 1 month. Using a scanning electron microscope, the researchers also determined that no streptococcal chains remained within 24 hours of contact.

Because bioactive fillers are generally inorganic—most commonly made using zinc oxide, silver, titanium, diamond, glass, or polymeric compounds like quaternary ammonium PEI—they don’t contribute to antibiotic resistance and can be designed to target specific pathogens.

Antimicrobial coatings have been found to reduce peri-implant mucositis, implantitis, and implant failure by preventing biofilm formation and bacterial growth on the surfaces of implants.

 Coatings kill on contact with agents like QACs and enzymes. Although coating placement helps reduce the amount of antibacterial needed, in some instances the coating’s antimicrobial properties can compromise implant biocompatibility and osseointegration.

Given the threat of antimicrobial resistance, the long-term release of antimicrobials could be disadvantageous. Because release begins immediately upon placement, treatment duration is often limited, and little is known about long-term effects. One study found that on average, the effects of a leachable agent lasted less than 1 year and, once depleted, could not be recharged.

In addition to agent longevity, concerns have been raised about appropriate doses. Because their release is uncontrolled, antimicrobials may deploy too quickly and become depleted before therapy is complete. Finally, the inability to target specific microbes can have repercussions on the oral biome, causing an imbalance between good and bad bacteria, like S mutans.

Despite the challenges, antimicrobials have improved dramatically over the past few decades, and researchers continue to make strides in terms of dose deployment, duration, and control. In the future, clinicians can expect to see strategies that address the drawbacks of agent-release and contact-killing methodologies and more effective ways to reduce biofilm and bacteria.

Rupf S, Balkenhol M, Sahrhage TO, et al. Biofilm inhibition by an experimental dental resin composite containing octenidine dihydrochloride. 

. 2012;28:974-984. doi:10.1016/j.dental.2012.04.034

Takahashi N, Nyvad B. Caries ecology revisited: microbial dynamics and the caries process. 

. 2008;42(6):409-418. doi:10.1159/000159604

Sakaguchi RL. Review of the current status and challenges for dental posterior restorative composites: clinical, chemistry, and physical behavior considerations. 

. 2005;21(1):3-6. doi:10.1016/j.dental.2004.10.008

Chen L, Suh BI, Yang J. Antibacterial dental restorative materials: a review. 

Ramburrun P, Pringle NA, Dube A, Adam RZ, D’Souza S, Aucamp M. Recent advances in the development of antimicrobial and antifouling biocompatible materials for dental applications. 

. 2021;14(12):3167. doi:10.3390/ma14123167

do Amaral GS, Negrini T, Maltz M, Arthur AR. Restorative materials containing antimicrobial agents: is there evidence for their antimicrobial and anticaries effects? A systematic review. 

. 2015;61(1):6-15. doi:10.1111/adj.s12338

Morones JR, Elechiguerra JL, Camacho A, et al. The bactericidal effect of silver nanoparticles. 

. 2005;16(10):2346-2353. doi:10.1088/0957-4484/16/10/059

Makvandi P, Jamaledin R, Jabbari M, Nikfarjam N, Borzacchiello A. Antibacterial quaternary ammonium compounds in dental materials: a systematic review. 

. 2018;34(6):851-867. doi:10.1016/j.dental.2018.03.014

Jiao Y, Tay FR, Niu L, Chen J. Advancing antimicrobial strategies for managing oral biofilm infections. 

. 2019;11(28).doi.org/10.1038/s41368-019-0062-1

Mitwalli H, Alsahafi R, Balhaddad AA, Weir MD, Xu HHK, Melo MAS. Emerging contact-killing antibacterial strategies for developing anti-biofilm dental polymeric restorative materials. 

. 2020;7(3):83. doi:10.3390/bioengineering7030083

Tiller JC, Liao CJ, Lewis K, Klibanov AM. Designing surfaces that kill bacteria on contact. 

. 2001;98(11):5981-5985. doi:10.1073/pnas.111143098

Montoya C, Roldan L,Yu M, Valliani S, Ta C, Yang M, Orrego, S. Smart dental materials for antimicrobial applications.

 2022;24:1-19. doi:10.1016/j.bioactmat.2022.12.002

Imazato S, Chen J, Ma S, Izutani N, Li F. Antibacterial resin monomers based on quaternary ammonium and their benefits in restorative dentistry. 

. 2012;48(2):115-125. doi.org/10.1016/j.jdsr.2012.02.003

Beyth N, Yudovin-Farber I, Bahir R, Domb AJ, Weiss EI. Antibacterial activity of dental composites containing quaternary ammonium polyethylenimine nanoparticles against Streptococcus mutans. 

. 2006;27(21):3995-4002. doi:10.1016/j.biomaterials.2006.03.003

Raszewski Z, Nowakowska D, Więckiewicz W, Nowakowska-Toporowska A. The effect of chlorhexidine disinfectant gels with anti-discoloration systems on color and mechanical properties of PMMA resin for dental applications. 

. 2021;13(11):1800. doi:10.3390/ polym13111800

Articles

As dental materials with antimicrobial properties become more common it’s important to be educated about how they work and the benefits and risks they can provide patients.

Understanding Antimicrobial Dental Materials

Understanding Color: How Materials Get Their Looks. Image: © belahoche - stock.adobe.com


Esthetics is key in restorative dentistry. Although mechanical function is paramount in successful restorations, the primary concern for many patients is esthetics. As important as texture and contour are, color is perhaps the most critical aspect in achieving impeccable esthetics.

“In the past, esthetics of dental restoration were not as achievable as they are today,” says Amelia Triplett, junior research scientist at products and materials manufacturer BISCO. “Esthetics took a back seat to the important mechanical properties required of a dental restoration. Now, science and technology have advanced enough to ensure the strength [required] of a restorative material using chemistry, and we are able to have greater focus on the esthetics.”

With the strength issues handled, esthetics can take center stage. There are strong materials easily customizable for color and opacity, allowing for more natural-looking restorations. In addition to these chemical advancements, Triplett says, clinicians now have the tools of color science and technology, such as spectrophotometry and light control, to aid in the shading process.

“We’ve got the physical strength requirements taken care of,” Triplett says. “Now the artistry of restorative dentistry can shine through.”

A big component of this artistry is color. Although we were all introduced to the color wheel in kindergarten, color theory in dentistry is a little more complex than the old childhood mnemonic ROYGBIV.

At its most basic level, light is the key to color. To make a color, light is reflected from a surface or filtered through something translucent. For example, according to subtractive color theory, blue only appears that way because it absorbs the colors that are not blue (red and green) but reflects blue light.

According to the Munsell color system, color is described by hue, value, and chroma. Developed in the early 1900s by Albert H. Munsell, the system was the first to separate color into the 3 dimensions and apply a numeric value to colors.

In this context, hue is defined as “the dominant range of wavelengths in the visible spectrum that yields the perceived color, even though the exact wavelength of the perceived color may not be present.”1 In plain language, the hue is the color. Value is the quantity of light that is returned from a material; essentially, the lightness of the color, or how dark the color falls on a black-to-white scale. Chroma refers to the saturation or intensity of the hue and is inversely linked to value.

Although hue, value, and chroma play a large role in coloration, the opacity of a material also affects the appearance of color. Materials that are transparent allow light to pass through with minimal interference, simplifying color matching. In comparison, opaque materials reflect and absorb light.

However, things get complicated when it comes to translucency. Translucent or semitranslucent materials (such as a tooth’s surface) scatter, absorb, and transmit light, affecting how the material interacts with light. This makes it much more difficult to determine shade. For example, in crowns, higher translucency means less light is reflected, lowering the crown’s value.

“Depending on the thickness of the material, translucency allows the underlying color to show through in varying degrees,” says Shotaro Matsubara, CEO of Tokuyama Dental America. “It will affect the value and chroma of the final shade.”

In short, the more translucent the material, the less light is scattered within it, and the more its color will be affected by the surrounding colors.

“Translucent materials will take on the color of the background, as the light reflected from more colorful/opaque background objects will be able to pass right though a translucent object easily,” Triplett says. “The thickness in which the material is used also has a more pronounced effect on the perceived color of translucent materials than it does on the perceived color of opaque materials.”

Fluorescence also plays a role in restoration color. Fluorescence is the emission of light from a material that has absorbed light, most often emitted in a longer wavelength. In natural teeth, fluorescence usually occurs in dentin, as it is highly organic. To mimic this, fluorescent powders are often added to restorations to bolster the amount of light returned, masking discolorations and decreasing the chroma—particularly beneficial in high-value shades where it can increase value without hurting translucency.

Triplett notes that dental materials are also affected by molecules within that interact with visible light wavelengths. The color of a material can be affected by the light in which it is viewed, because if the light does not have a specific wavelength band, the material cannot reflect it.

Regarding dentistry, Triplett says, one of the molecules involved in light-curable materials is camphorquinone. This material absorbs the near-UV visible light from curing lights and initiates free radical polymerization.

“Because camphorquinone absorbs near-UV visible light, which to us appears bluish in color, camphorquinone reflects the other wavelengths of light, resulting in this chemical appearing yellow to us,” Triplett explains. “If camphorquinone is not optimized in a dental restorative material, it can possibly cause an unesthetic yellow color.”

When it comes to color in dental materials, colorants (pigments or dyes responsible for the chromatic reflection of light with the material) are employed to create certain shades. The chemical composition of a particular colorant absorbs certain sections of the visible spectrum.

“Most dental materials get their color from adding chemical color—pigments and dyes to achieve the various shades and opacity needed to blend with natural dentition,” Matsubara says.

These pigments and dyes, Triplett clarifies, are used in small amounts labeled Generally Recognized as Safe or approved under the Federal Food, Drug, & Cosmetic Act (FD&C) or by the United States Food and Drug Administration. They include titanium dioxide and FD&C Red No. 40. However, in recent years, alternatives to colorants have emerged.

“The assumption that we have to use chemical color, pigments, and dyes to achieve shade matching in resin composites has really had a paradigm shift in the [past] few years,” Matsubara says. “In 2019, an alternative option launched with the release of OMNICHROMA. The resin composite relies on structural color—the interaction between structure and light to create color—to shade match to surrounding tooth structure.”

This concept of structural color was a novel development for resin composites. A 1-shade universal composite, OMNICHROMA employs supranano spherical fillers that can shade match any color from A1 to D4. In one study, conventional A2-shade resin composites (composed of 5-50–nm fused silica fillers and 100-nm spherical fillers) were compared with structural color composites. Researchers determined that the structural color composite (comprised of 260-nm spherical fillers) exhibited lower color differences between natural tooth and restored areas and a higher color adjustment potential.

“When OMNICHROMA was first launched, there was a bit of hesitation since the concept of structural color was never considered viable for resin composites,” Matsubara says. “Structural color is a natural way to see color and has been studied for practical application in many industries due to its long-term stability and environmentally friendly properties.”

Another unique benefit of OMNICHROMA is its ability to shade match post bleaching, or as teeth change color over time. “This is a big benefit for esthetic dentistry, because patients who need anterior restorative work no longer have to decide immediately [whether] they plan to whiten their teeth,” Matsubara explains. “OMNICHROMA gives them the freedom to decide when and how much they want to brighten their smiles in the future.”

When it comes to choosing a material, there are several things to keep in mind that can affect color, particularly in the long run. “A hydrophilic material will take on water over time, which can affect the perceived color of the restoration. Additionally, a high monomer percentage in a material’s composition can lead to higher water sorption. It is important to ensure these materials are properly cured, which can increase a material’s hydrophobicity,” Triplett says.

This is of particular importance with materials that have lower depths of cure, such as highly opaque materials. To lower the chances of marginal discoloration, clinicians should choose materials with minimal shrinkage during curing. Additionally, Triplett says, materials should be polishable to help prevent plaque accumulation and bacterial adhesion.

“In addition to water sorption, exposure to UV light causes degradation of dental materials over time and this degradation can cause color change,” she states. “Proper curing can help decrease water sorption, as well as choosing less hydrophilic materials for restoration. When it comes to slowing UV degradation of the material, a chemical called a UV stabilizer can be included in formulation.”

Whichever material clinicians choose, they cannot forget one important thing: Color is all about light. Light quality is one of the most important factors when identifying shades. Everything can affect the quality of light, including season, weather conditions, time of day, or whether the light is natural or artificial.

“Dentists should keep in mind under which kind of light they perform shade matching,” Triplett says. “Restorative dental materials have the potential to look slightly different under different light sources. It is recommended to perform shade selection using natural light or by employing a D65 daylight lamp, if possible.”

Light comes into play before the material ever makes it to the dentist’s chair.

“Materials get their esthetics through careful and meticulous optimization of each component of the material’s formulation,” Triplett says. “This includes the photoinitiators, monomers, inorganic fillers, and tints. We make sure to study how light interacts with each of our products with spectrophotometry, intense light irradiation, and measurement of refractive indices.”

Once a material has made it out of development and into the chair (and the patient’s mouth), the challenges do not end. Over time, dental materials are subjected to all the stresses faced by natural teeth, including the patient’s lifestyle, eating and drinking habits, and oral hygiene.

“The best way a clinician can protect his patient from these factors is to have a strong, reliable bonding, finishing, and polishing protocol,” Matsubara says. “This will limit any lifestyle factors that may impact the restorative in the future. Here, a single-shade composite that adapts to the changing tooth color will be handy.”

The bottom line when selecting esthetic materials is that clinicians find something that meets their clinical needs and satisfies the patient. “Oftentimes we are swept away by the possibilities when we look at esthetic material and how many options we have to achieve these amazing restorations if we buy a complex composite system that has every shade under the sun,” Matsubara says. “If you have patients that necessitate a huge system, then yes, it makes sense. If you don’t use a wide range of shades in your general restorations, you probably don’t need to spend the money for a complex kit. We have the single-shade system option, and a reduced shade system—a very user-friendly esthetic composite kit, Estelite Omega, in collaboration with Newton Fahl Jr, DDS, MS. He helped us design a system that would achieve high esthetics with only 11 well-crafted shades.”

The options are out there, the science is advancing, and the color of restorative materials is constantly improving, ensuring that restorative dentistry becomes more esthetic by the day.

“We love the science,” Triplett says. “[Although] we employ traditional dental material chemicals in our products, we are also always aiming to improve our technology and studying new chemistries to apply to future products...The dentists we connect with are an integral part of our product development in R&D. It is always a pleasure to discuss the science behind dental materials.”

1. Sikri VK. Color: implications in dentistry. 

. 2010;13(4):249-255. doi:10.4103/0972-0707.73381

2. Brewer JD, Wee A, Seghi R. Advances in color matching.

. 2004;48(2):v, 341-358. doi:10.1016/j.cden.2004.01.004

3. Kobayashi S, Nakajima M, Furusawa K, Tichy A, Hosaka K, Tagami J. Color adjustment potential of single-shade resin composite to various-shade human teeth: effect of structural color phenomenon. 

. 2021;40(4):1033-1040. doi:10.4012/dmj.2020-364

We take a deep dive into the science behind the colors of restorative materials, expanding on why they perform as they do and how to optimize them for esthetics that patients desire. 

Understanding Color: How Materials Get Their Looks

Money, money, money. It’s always in the back of our minds, but sometimes it should really be front of mind. You may have pursued dentistry in order to help patients, but along the way you’ve accrued a sizeable debt, and that’s why a long-term plan is essential to your financial success. The profession can be very lucrative, but only for those who know how to navigate it. Besides allowing you to repay loans, making a little extra money never hurts. But that’s only half the battle: if you want to maximize your income, you must constantly evolve.

According to Bruce Bryen, CPA, CVA, a valuation expert at Baratz & Associates, there are 2 ways to achieve that goal: by “making the most money and…keeping the most money.”

The road to success starts with your first step out of dental school. What types of dentistry do you want to practice, and where? Where should you invest time and money? What equipment and technology might benefit you the most? What is going to have the biggest impact on your bottom line in 20 years? Should you invest time and money on a subspeciality?

Until recently, most students envisioned starting as an associate and someday becoming their own boss. However, with the rise of dental service organizations (DSOs), there are other opportunities available to new DMDs. Data from the Health Policy Institute of the American Dental Association says that, in 2019, 10% of dentists over 50 and 20% of those under 35 worked at DSOs—an increase from 2015 of 5% and 16%, respectively. With this trend comes a decline in private practices: in 2005, 49% of dentists under 35 were in private practice, but in 2019, only 31% were.

DSOs pay good starting salaries, which can be tempting for those with student-loan obligations in the neighborhood of half a million dollars. Besides, working for a DSO removes nonclinical responsibilities, freeing up more of your time.

“A DSO is a great opportunity for someone who wants to earn a significant amount of money now but…not worry about [it] down the road,” Bryen says. “It’s a great thing, particularly if you’re younger or…at the end of your career. If a person wants to make a lot of money immediately, without the responsibility of building for an acquisition or a partnership…[a] DSO is the best way to go.”

Although clinicians at DSOs are likely to receive annual pay increases, they may never earn as much as a practice owner. They can benefit, of course, from the paid vacations, health insurance coverage, and retirement plans that a private practice may not be able to match, but they can also expect to eventually hit a ceiling in terms of salary and external opportunities. For instance, they may find it difficult to leave the DSO system and become a partner elsewhere because they lack administrative skills.

“The DSO is…not for everybody,” Bryen points out. “If you’re just interested in the clinical skills, you’re going to be doing what you’re doing forever. That’s not necessarily bad; you may make $200,000 a year to start. But after 10 years go by and you’re…making [only] $225,000, you may start thinking it’s not for you,” he explains. “That’s where the person working at a DSO needs to be careful.”

Dentists at DSOs can expect to hit peak income within 5 to 14 years of starting, but after that, their salaries decrease in comparison with those of private clinicians, who see continuous growth over the course of their careers, according to Bryen. To avoid stagnation, dentists working at DSOs should “learn about other aspects of the business,” Bryen advises. Then “you’ve got a better chance to progress; that’s when you’re really going to make some money.” 

Joining a DSO upon graduation may be tempting, but private practice is the most lucrative option in the long run. As associates, dentists can develop business as well as clinical skills. They will make less than at a DSO (probably around 30% of collections), but they will get an idea of how a practice is run and thus will be able to make informed decisions about ownership. If they decide to buy or start a practice, they’ve got a leg up on the financial side of things over a dentist at a DSO.

“If you want to build for the future, you should go work for somebody,” Bryen asserts. “You may not make as much money as the person going to work for the DSO, and you’re going to take on more responsibility…. But, if you want to build, if you want to buy a practice someday, then you’ve got to take on the responsibility of learning [about] accounting, insurance, etc.”

Although the long-term benefits may be impressive, your first few years probably won’t be easy, as purchasing or setting up a practice comes with costs of its own. “You’re definitely looking at some investments to get off the ground,” Bryen admits. “But you’ll make it if you stick to it and embrace the responsibility. There’s no question that over time the dentist will build the equity to allow them to do other things, like purchase a vacation home or whatever they dream of.”

You’ll get that mountain cabin or beach house because you’ll be able to leverage the practice to borrow money. After all, once dentists become owners, they’re building equity year over year as they pay down loans. Once debts are discharged, a successful practice will be extremely valuable.

“Dentists that buy a practice have something they are building, whereas with the DSO, they’ve got a good salary, but when they owe $300,000…, they’re using a big portion of that salary to pay down the debt,” Bryen says. “It’s good they’re paying down the debt, but unlike the dentist…buying the practice, they don’t have…[an] asset.”

In addition, owners may be taking home half the collections, and when it’s time to sell, they may be able to ask for up to 100% of collections, not a bad nest egg at the end of a career.

Irrespective of the path a dentist takes, staying abreast of the latest in technology and techniques is also critical to ensuring business success. Investing in education keeps you at the forefront of the profession and sets you apart from the competition. It may require investments of money and time, but it’s worth it in the long run.

“The continuing education and study clubs are critical—and not just for what you’re going to learn, but for who you’re going to meet, and what you’ll learn from them. Maybe somebody’s doing something that you’re not doing; well, then you’re going to learn.”

Continuing education isn’t limited to clinical skills, however. Understanding business is equally important for an owner. Although there are seminars that can teach you how to run a business, Bryen recommends retaining a good dental CPA. If you do, “you’re going to learn from that person about how to conduct your business. If you don’t have a good dental CPA, you’re missing something, and it’s going to cost you a lot of money.”

Dental CPAs are attuned to the needs of the industry and understand that many dentists, although clinically adept, are a bit lost when it comes to business, largely because they were not taught business in school and don’t have someone to show them how it’s done. A good dental CPA can be that guide, especially one who has worked with other practices.

“They [dental CPAs] can take what they’ve seen in other practices and apply it to yours,” he says. “And that will make the practice grow, while also teaching…dentists the skills to run their business. If you’ve got somebody that’s good, it’s important to take advantage of what that person knows. That’s what is going to make you a lot of money.”

Partnering with a dental CPA can also ensure that dentists get the appropriate guidance early on. There are always risks attendant to borrowing large amounts of money (like the capital to buy a practice), but a team of experts can mitigate those risks. 

“A dental CPA, a lawyer—these professionals can look at the agreements and tell you what to look out for. The financials can tell you an awful lot, and you’ll need people to point out the different facets of the business deal. When you buy a house, you hire someone to tell you what’s wrong with it. It’s the same thing; the dental practice evaluator can tell you what they see, and sometimes they aren’t obvious things.”

Whether you decide to work for a DSO or hang out your own shingle, the capstone of success is patient satisfaction, more so than business acumen and clinical excellence. Although it may not seem like it at first, building—and maintaining—a happy, loyal patient base is the best way to keep your chair (and thus your savings account) full.

“The reputation of the dentist is really an important thing,” Bryen notes. “Being respectful and having your staff understand how to treat patients is key.… This means running on time and ensuring you…speak with each patient. If you don’t give the patients the respect they deserve, it’s going to backfire.”

This is particularly important because often patients will simply go elsewhere instead of raising a complaint. If you’re always 30 minutes late, you’re wasting the patient’s time, and they are less likely to return. Don’t wait for a patient to complain before making improvements: they may not be comfortable telling you about their frustration. You are responsible for recognizing—and rectifying—any problems.

“From a noneconomic standpoint, this is the kind of thing that can hurt…relationships and stop referrals,” Bryen warns. “The dentist or the hygienist may be terrific…, but waiting a long time…is…upsetting, and it’s going to hurt the dentist because word of mouth is the best referral source.” In the end, it is your reputation that guarantees your financial well-being.

References
1. HPI: shifting practice patterns. American Dental Association. December 3, 2021. Accessed April 12, 2023. https://www.ada.org/publications/new-dentist-news/2021/december/hpi-shifting-practice-patterns

What strategies help dentists earn the most over the course of a career?


Long-term Thinking Key for Clinicians

Easier is not always best, but it is often a whole lot better. When it comes to endodontics, why make it more complicated than it needs to be? Thanks to a constantly growing suite of products, materials, technology, and accessories, these days endodontics is easier than ever—especially if you have the right tools in your arsenal.

“Perhaps the most common question [asked] during my courses is which equipment to buy for a more effective endodontic technique upgrade,” says educator Carlos Spironelli Ramos, DDS, PhD, MS. “My background as a teacher and researcher tells me that the most critical thing when adopting a new material or technique is to offer an endodontic treatment that results in greater success rates.”

But what does that mean for individual practitioners? It depends. For some tasks, there are many equipment options that will get the job done, and personal preference plays a large role. But what are the tools that every clinician should have to get the job done more easily?

When it comes to tools that will get the job done effectively—with proven success—Dr Ramos immediately recommends an apex locator.

“I would start with those [tools] endorsed by evidence-based endodontic research,” he says. “The apex locator stands as my first choice. This equipment has vast scientific experimentation behind it, exponentially increasing the degree of successful results, at a reasonable cost.”

The apex locator is an important tool in determining the length of a root canal, and apical constriction positioning. Study findings have shown that all 4 generations of apex locators are accurate in measuring working length, and that they may perform better than radiographs in determining working length.

 With this research behind them, apex locators are a no-brainer addition to any endodontic treatment approach.

And there are plenty to choose from, all with their own benefits. Lightweight and compact, the EndoSync A.I. from Brasseler USA can accurately identify the location of the file in the canal despite the presence of blood, saline, irrigants, or other materials. A large LCD screen, audible warnings, and automatic calibration all combine to increase ease of use.

If you are looking to go even smaller than the compact EndoSync A.I., Polaroid Healthcare has introduced NEO, an apex locator roughly the size of a smartwatch. Measuring just 46 × 43 × 16 mm, the NEO can clip onto a watchband, bib, ruler—wherever is most convenient for the clinician. Even better, the touch screen display responds to gloved fingers, so you won’t be left swiping futilely.

For clinicians who want a more prominent display, the Root ZX II (J. Morita) features an easy-to-read color LCD screen, and its ratio technique is said to deliver an accuracy of 97.5%. Other options such as the ProMark (Dentsply Sirona), CanalPro (Coltene), and EndoPilot (Komet USA) all streamline the process of determining how far instruments should go into the canal and when the preparation should end, reducing the risk of root perforation and other complications.

“Some critical devices have experienced significant technological development in simplifying usage, which in turn creates a smoother learning curve for the operator,” Dr Ramos says. “This should be the essential principle, and apparently, it is what is being taken into account [in development].”

It is easy to jump to the exciting technological tools that assist in treatment, but there are also products that help before the procedure ever begins. Pulp vitality testing is critical in determining the health of dental pulp. Different testing types, including temperature/thermal, electric, percussion, and pulse oximeter, are all effective approaches to varying degrees.

When it comes to speedy, on-the-spot testing, thermal testing can be a quick and easy approach. Endodontic sprays such as Cold As Ice (Dental Creations) induce rapid pulpal response thanks to a low liquid temperature of –15.2 °F. Easy to use (and environmentally friendly) Cold As Ice produces a rapid response for instant results.

 Pulp Vitality Spray is another option for stimulation of nerve endings. Significantly colder than ice or ethyl chloride, PacEndo Vital-Ice tests the vitality of the tooth before a procedure ever begins.

Although thermal testing is a simple way to get results, pain-relief drugs, for example, may cause false readings as they may mask vitality issues. To avoid this, some practitioners are exploring electric testers such as the Digitest

 3 Pulp Vitality Tester (Parkell). The Digitest 3 uses electricity to stimulate teeth and compare responses between healthy and unhealthy teeth to identify issues.

Another option in pulp vitality testing is a pulse oximeter. Recent study results have shown that pulse oximeters provide the most accurate diagnostic results when compared with thermal testing and electric pulp testers.

 By comparing oxygen saturation values from a patient’s finger with pulp oxygen saturation values in these studies, researchers were able to establish pulp vitality.

As every clinician knows, irrigation is critical in endodontic procedures to disinfect and prevent reinfection—so critical, in fact, that it is a particular focus of Dr Ramos and the endodontic team at Pac-Dent.

“Many projects are under development, but the endodontic division’s primary focus is irrigation/disinfection,” Dr Ramos says. “Pac-Dent’s vocation is the development of the elements that make up irrigation in endodontics. We are working together to improve the quality of the chemicals involved in irrigation and the mechanical irrigation delivery system.”

Although there are many nonbactericidal and bactericidal irrigants available, including saline, chlorhexidine (CHX), sodium hypochlorite (NaOCl), and more, there are also some sidekicks that can make irrigation more effective. The CanalClean

 Irrigation Kit from Vista Apex includes 2 solutions that eliminate the need for ethylenediaminetetraacetic acid (EDTA), CHX, and a rinsing agent. The kit’s Chlor-XTRA

 6% NaOCl formula penetrates into lateral canals, thanks to lowered surface tension. This is coupled with Smear-OFF

 2-in-1, an EDTA/CHX mix that optimizes smear layer removal. Chlor-XTRA and Smear-OFF 2-in-1 will not form a precipitate when used together, negating the need for an extra rinsing step and making irrigation simpler.

 2in1 Irrigating Solution is another option for final rinse smear removal. Premixed and ready to use after NaOCl, it saves time because you do not have to use EDTA and CHX sequentially. With a demonstrated bacterial kill rate of 99.99%, it is an effective solution for irrigation protocols.

Irrigants are important, but the irrigation approach is just as critical. The tools used to enlarge the root canal space are limited and cannot always conform to the intricacies of the patient’s anatomy. One method of ensuring that all of the canal is properly irrigated is through the use of ultrasonics, which can enhance the ability of irrigants to reach all portions of the canal. Ultrasonic activators such as the EndoUltra

 Cordless Ultrasonic Activator provide enhanced acoustic streaming through cavitation and better penetration into the canal (and, in the case of the EndoUltra, have the convenience of being cordless).

Dr Ramos agrees that mechanical irrigation can be of huge benefit, and believes that the iVac

 LED Piezo Ultrasonic Scaler (Pac-Dent) represents an effective way to achieve effective irrigation.

“I have to highlight the iVac, a system that unites the 3 fundamental principles of mechanical irrigation: ultrasonic activation, negative apical pressure, and concomitant irrigation,” he says. “The next step will be to offer a complete system, with an ultrasonic unit designed and dedicated to the iVac. In this way, Pac-Dent aims to offer the best in chemical and physical irrigation approaches, and still provide a technique that, in addition to being efficient, is safe regarding apical extrusion.”

Perhaps as important as irrigation is isolation. Isolation prevents the potential contamination of endodontic preparations, protecting both the working field and the oral cavity. The rubber dam has long been a staple of endodontic isolation and for good reason: It may be an oldie, but it’s a goodie.

For rubber dam skeptics, products such as the True

 Dental Dam (Clinician’s Choice Dental Products Inc) may turn them into converts. True glides smoothly through contacts, easily tucking into the sulcus for confident placement. Tear resistant and extremely durable, the material can be easily stretched to create a clean, clear field. Clinicians looking for hardy tensile strength can also turn to Smart Dam dental dams (Cranberry). Powder free and with 98% less latex protein, Smart Dams come in unscented and nonlatex and latex spearmint-scented varieties.

When concerns about dental dam placement or leaks arise, products such as OraSeal

 (Ultradent) can provide additional protection. OraSeal caulking material can be used to repair rubber dam leaks, effectively adhering to even wet rubber dams, sealing the rubber dam to protect the gingiva. Another product from Ultradent, J-Temp

 Temporary Resin, helps support structure for isolation clamping and helps block endodontic irritants.

“J-Temp is a temporary resin to be applied to seal the interappointment cavity, creating a structure to isolate complex cases and working as a barrier so that irrigants do not leak into a patient’s mouth,” says Renato Miotto Palo, DDS, PhD, MS. “This is a multifunctional material designed to be easy to apply, resistant between sessions, and easy to remove, exactly what every professional needs when dealing with endodontic treatment.”

There are so many other excellent tools and accessories available on the market to simplify endodontic procedures, from lasers to file systems, to burs and sponges, to obturation systems and motors, that it is hard to limit a list of accessories to just a few. Advances in endodontic handpieces, bioceramics, cone-beam computed tomography, and loupes are also pushing endodontics forward in an exciting manner. And then of course, there is the noninvasive multisonic ultracleaning technology of the GentleWave

 System, which combines irrigants with waves of broad-spectrum acoustic energy. Now it is becoming harder than ever to identify the top tools and accessories for endodontic care.

“For example, we have the new generation of endodontic motors and instruments,” Dr Ramos says. “Open motors, with the possibility of adjusting rotation and torque and angles in reciprocation, are added to intelligent preset programs with rotational and alternating movements working in synchrony with heat-treated engine-driven NiTi [nickel-titanium] instruments of better performance.”

These advances become even more thrilling when you consider how many more products and innovations there are on the horizon.

“Some non- to minimally invasive intervention proposals are on the table and will require long-term scientific proof,” Dr Ramos continues. “Innovations that present an additional improvement to what already is consolidated by research tend to succeed better among colleagues than disruptive innovations.”

Regardless of what comes down the road, clinicians can find comfort in the treasure trove of products already on the market, while ruminating positively on the innovations of the future.

“The future of endodontics appears to be well delineated today, but it needs the corroboration of clinical tests,” Dr Ramos concludes. “Once again, time reigns supreme in designing a future that perhaps we can premeditate now.”

Nasiri K, Wrbas KT. Accuracy of different generations of apex locators in determining working length: a systematic review and meta-analysis. 

 2022;34(1):11-20. doi:10.1016/j.sdentj.2021.09.020

Martins JNR, Marques D, Mata A, Caramês J. Clinical efficacy of electronic apex locators: systematic review. 

. 2014;40(6):759-777. doi:10.1016/j.joen.2014.03.011

Patro S, Meto A, Mohanty A, et al. Diagnostic accuracy of pulp vitality tests and pulp sensibility tests for assessing pulpal health in permanent teeth: a systematic review and meta-analysis. 

. 2022;19(15):9599. doi:10.3390/ijerph19159599

Sadique M, Ravi SV, Thomas K, Dhanapal P, Simon EP, Shaheen M. Evaluation of efficacy of a pulse oximeter to assess pulp vitality. 

With the advent of new technologies, endodontic procedures become easier and more effective with a variety of tools and techniques. Here are a few of the key accessories behind cutting-edge endodontics.

Making Things Easier With Endodontic Accessories

Understand the Differences Among Clear Aligner Materials


Long gone are the days of wire-and-bracket braces being the only option for managing malocclusion, crowding, and other issues requiring orthodontic intervention. The development of clear aligner therapy offers patients a more esthetic alternative to traditional braces.

Clear aligners are booming in the market, but what are they 
made of and how do these materials differ from one another? 