Terri Lively

	Dental composites have been a restorative material since the middle part of the 20th century. In the early ’60s, Dr. Rafael Bowen was the first to discover that chemically treating silica particles would prepare their surfaces to bond with a polymer base (Bisphenol A-glycidyl methacrylate, bis-GMA) when cured to create a strong restorative material. 

	However, the early composites, which were called “white fillings” in the vernacular of the day, did not have the depth and breadth of application that today’s dental composite restorative materials do. Nor were they as popular or durable as amalgam fillings at the time. It would be at least another 10 years before dental composites enjoyed widespread use by dental practices. 

	However, times have changed, and the dental composite materials have also. Improvements in filler technology and translucency mean that dental composites today have improved mechanical properties and the esthetics of which early developers of white fillings could only dream. Also, the resin component has changed some, too, reducing polymerization shrinkage and the problems it can cause. In addition, bonding systems improved, too, which has extended the lifetime of composite restorations considerably. 

	When Peter Auster, DMD, FACD, started in dentistry in 1980, there were two composites he remembers on the market, Adaptic (Johnson and Johnson) and Concise (3M). Dr. Auster was attending the University of Pennsylvania School of Dental Medicine at the time, and he said that the composite you used had a lot to do with where you studied.  

	“Different schools use different composite. I went to Penn at the time, and they were exclusively using Concise,” Dr. Auster says. “Concise was an interesting composite. It filled spaces, held very nicely, and was pretty strong, but it was extremely rough and virtually unpolishable.”

	These early composites were macrofills, meaning the particle sizes inside the coupling agent are plentiful and were known for their strength and durability. Dr. Auster says it was not until the late 1980s or ’90s that composite materials polished well. These composites had smaller particles and were called microfills and they were popular for work on anterior teeth. 

	“Many of those microfills are still on the market because they are beautiful, and you can polish them nicely,” Dr. Auster says. “They can mimic teeth far better than any previous material. That was something that the Adaptics of the market could not do.”

	However, a problem with those microfills is that they were weak. Their lack of mechanical properties made them inadequate for the posterior teeth. Moreover, Dr. Auster says their strength on the incisal edge of a tooth is questionable and many dentists would use a macrofill underneath a layer of microfill for increased strength.

	Composites moved to microhybrids in the ’90s, which provided the esthetics of microfills and the strength and durability of macrofills. Microhybrids addressed concerns that dental composite restoratives were not appropriate for the posterior. The first hybrids had some problems, per Dr. Auster, but the materials improved as the decade wore on, becoming stronger and easier to polish. 

	Then, with the turn of the millennium, the nanohybrids emerged. These were improved versions of the hybrids with tiny particles that would band together to mimic large particles, making them stronger than microhybrids.

 Furthermore, the resins began using silorane bases to reduce polymerization shrinkage, which led to many challenges for restorative outcomes and longevity. Dr. Auster says you could at last comfortably use dental composites for virtually anything. 

	“It was an era of specialization. Our armamentarium began including low viscosity flowables and cements; high viscosity core materials, and many textures of general composites,” Dr. Auster says. 

To read more about the History of Composites, please 

	Starting in 2010, manufacturers introduced some exciting material

 improvements. Dr. Auster says every product was leapfrogging over the other. While the changes were small for the most part, manufacturers were making significant improvements in areas like improved performance in ambient light and better handling than before, as well as creating less sticky materials. 

	“One product wasn't a whole lot different than the product that came before it, but there were some cool changes that came out during that period,” Dr. Auster says. 

	He says the number one change in his mind was the introduction of bioactive products by Pulpdent with ACTIVA BioActive Restorative. Per 

, this generation of composites not only replace the missing tooth volume but also work to remineralize and serve as antibacterial agents in restorations.

 These characteristics help the materials replace lost mineral, fight off recurrent decay, neutralize acid and repel proteins, as well as suppressing biofilm growth and acid production. Moreover, these materials are often showing low toxicity to other cells, much like the resins in use in many dental composites, and also protect the dental pulp, as well as encouraging a third layer of dentin formation.

To read more about Bioactive Dental Composites in the 

	“I am sure probably in the next five years that every single company will have something that's either called bioactive or bioceramic,” Dr. Auster says. 

	Another area that he sees improving today and for the future is that every company is working on handling. He says if you look at their ads, it’s the first feature they mention. 

	“Companies now speak with pride about product ‘ease of use’ and they mean it!” Dr. Auster says.

	One contributing significant improvement over the years per Dr. Auster is the fact that there are less ambient light problems. Dr. Auster remembered about seven or eight years ago, the light in his office would set the material on the tooth before he had a chance to cure it with the curing light. 

	“It was mind-boggling,” Dr. Auster says of the ambient light issues. “But they've suddenly discovered how to deal with ambient light a whole lot better than they used to. I can put the material in a tooth, and ten minutes later, it is not set, which is great.” 

	Also, Dr. Auster sees that products are not sticking to instruments like they once were. 

	“We used to need to dip an instrument into an unfilled resin or constantly dry off the tip. But I find that with the better composites, you don't need an unfilled resin because they don't stick to the instruments anyway,” Dr. Auster says, adding “composite instruments have improved as well. This is a ‘golden age of composite dentistry’.”

	Also, heating the material improves the properties of this generation of composite, per Dr. Auster, which is something he did not like to do in the past. However, heating composite materials makes them softer and smoother. They behave like a flowable when you first put them on the tooth. Then, as the material begins to set, they harden somewhat so you can mold them. 

	“Theoretically, they flow better into the nooks and crannies,” Dr. Auster says. 

	However, if you ask Dr. Auster, the most incredible innovation to enter the marketplace in dental composites from the last 30 years is in the area of shade matching. 

	“The initial products had one color years ago. Then, they went to five and then up to ten. Then, some companies were forcing us to buy 36 shades. Of course, by the time the product cycle was over, half of those shades were hardened in our closets, and we had to throw them out when we finally needed them,” Dr. Auster says. 

	Today’s products are moving in a new direction, getting away from adding colors to create shades and working with the chemistry to have shade matching built-in to the composite. Dr. Auster thinks that all the manufacturers are already moving in the direction of fewer colors and products that are more compatible with the body. In other words, fewer shades and healthier products that will allow fluoride, phosphates, and calcium to diffuse back and forth between the product and the tooth itself. 

	“There are other companies that are following Pulpdent’s lead and coming out with products that are ‘dynamic’ for the lifetime of the material as opposed to passive products,” Dr. Auster says, “and I think that's going to be a theme as time goes on." 

 Lavigne, Courtney. “Dental Composites: Types and Recommendations.” Speareducation.com. Web. 13 December 2018. Web. < 

http://www.speareducation.com/spear-review/2017/01/dental-composites-in-2017-what-to-look-for-and-what-to-get

 Zhang, Ke et al. “Bioactive Dental Composites and Bonding Agents Having Remineralizing and Antibacterial Characteristics.” 

 vol. 61,4 (2017): 669-687. doi:10.1016/j.cden.2017.05.002

Articles

How dental composites have changed over time

	Digital clear aligner technology has been available as an orthodontic treatment for more than two decades, since Align Technology first introduced the Invisalign® system. Much has changed with the technology over time, including better materials, improved treatment planning, and more predictable outcomes. Moreover, the competitive landscape is changing, with new ways of marketing and delivering clear aligner therapy that have disrupted traditional doctor-led care.

	While some form of clear aligner technology has been available as an orthodontic treatment for more than 20 years, quite a bit has changed with this technology over time, including superior materials, improved treatment planning, and more predictable outcomes. The changes in the industry’s competitive landscape have been just as impactful.
	Despite all this, persistent misunderstandings remain in some dental professionals’ minds about who can do what when with clear aligner therapy. One expert described these ideas as having “staying power.”
	
	With the developments and changes in suppliers for clear aligners, let’s take a closer look at the field of clear aligner technology today. From what you should know about clear aligners and choosing a partner, to technological innovations, to how competition is changing business as usual, here’s what some of the players in the industry had to say.

	What you should know about clear aligners today

	When Tera Poole, DDS, was going through dental school and residency, someone asked her, “If you could be a utensil, what kind of utensil would you be?” At that time, she thought it was a far-fetched question.
	However, the clear aligner industry today reminds her of a utensil. Dr. Poole thinks of it as a three-pronged fork: One prong is the direct-to-consumer (DTC) players, another is the business-to-business (B2B), doctor-led clear aligner companies, and the third is the hybrid of both.
	
	“It’s kind of like the Wild, Wild West right now,” Dr. Poole says. “Everybody is innovating in different avenues, and there’s so much going on, which makes it really exciting.”
	
	Jerry Zilles, Vice President of Sales for Propel Orthodontics, has 20 years of experience in clear aligners, having been in the industry almost from the start. Zilles says if you haven’t had training on clear aligners in the recent past, you might be surprised to learn it is a different ball game than it was in the beginning.
	
	Zilles sees many applications for general dentists regarding clear aligner therapy. From minor lower crowding to restorative cases to pre-implant cases, he says the possibilities with clear aligners are exciting.
	
	“With the proper training you can do just about any case you wanted to with clear aligner therapy, no matter which company it is,” Zilles says. “They all have their different benefits, but in the right hands they can do just about anything traditional orthodontics could do.”
	
	Christophe Carsault, vice president of sales for orthodontics and preventive for the Straumann Group, which owns ClearCorrect, says clinicians should know that clear aligners have almost become a plug-and-play for any practice. Having the right partner is crucial because the market potential is enormous.

	“Seventy to eighty percent of the population is suffering from malocclusion. It is a great service to offer to a patient,” Carsault says. “And there is no need to work to try to develop a very sophisticated marketing campaign for your practice because you already have the patients in-house.”
	
	According to Align Technology, clear aligner technology offers millions of people around the world the opportunity for a beautiful, healthy smile. However, many do not realize that moving teeth through bone is a difficult process, requiring close doctor involvement, extensive knowledge, training, and experience.
	
	Clear aligners are class II medical devices regulated by the FDA, and are an appliance prescribed by doctors.
	“Invisalign clear aligner technology, pioneered by Align more than two decades ago, is helping to expand market growth by getting into the offices of general practitioner dentists to reach millions more people through technology rather than the manual process of bending wires and gluing brackets to teeth,” noted Frank Quinn, vice president, and general manager, U.S. of Align Technology.
	
	Jeff Rohde, MS, DDS, who practices in Santa Barbara, Calif., has been working with Invisalign clear aligner treatment since 2004 and considers clear aligners a staple at his practice. Recently, Dr. Rohde started some new cases with SureSmile

 from Dentsply Sirona, as well as some from OrthoFX™, and is excited about what he has discovered from the new companies.
	
	OrthoFX is a hybrid of consumer-directed and doctor-led treatment. While the company is using DTC marketing to build the brand, the treatment has a doctor who handles the digital scan, the attachment placements, and monitors movement.
	
	“They’re trying to find that sweet spot between the expensive Invisalign treatment and the haphazard nature of SmileDirect,” Dr. Rohde says.
	
	

Dentsply Sirona’s SureSmile provides technology that enables clinicians to provide treatments they might not otherwise. 

	
	Dr. Rohde says the most significant factor in whether a treatment works or not is patient compliance. If the patient wears the tray, then he thinks most treatments will probably work.
	
	“If the patient only wears aligners at night and doesn’t have all the daytime pressure on his teeth, no system is going to work,” Dr. Rohde says. “Success is still based on patient compliance across the board.”
	
	According to Align Technology, the Invisalign product portfolio can treat even the most complex orthodontic cases providing doctors with a range of products and price points available to treat their patients. The doctor determines which product to use and the price for the patient is based on treatment scope and complexity.

	While compliance plays an important role in the success of clear aligner treatment, many other considerations impact end results, according to Quinn. A significant factor in predictable, effective treatment is the efficacy of the product. This includes the digital treatment plan, the physical aligner, its features, and the materials it is made of, as well as the ability to manufacture a physical aligner that can express the desired movements prescribed by the doctor based on a diagnosis and treatment plan.
	
	Zilles thinks more general dentists should consider offering clear aligner therapy in their practices. He says not offering it is doing a disservice to patients from a health standpoint. He sees benefits for patients ages 30 to 80, many of whom have lived with lower anterior crowding most of their lives.
	
	“We need to realize that 50 is the new 30, and the patients are going to have these teeth for their entire lives,” Zilles says. “We can fix this today, and you can have straight teeth for the next 50 or 60 years.”
	
	Through Align Technology, dentists have access to Invisalign Go, a system designed to help dentists incorporate Invisalign clear aligner treatment into their practices. Quinn explains that Invisalign Go provides support for case selection through treatment planning to help dentists treat mild to moderate cases as part of a comprehensive treatment plan.
	
	“With tools on the iTero digital scanner such as the Invisalign Outcome Simulator and TimeLapse, patients, many of which are in the everyday dental hygiene chair, can easily visualize their future smile,” Quinn says.
	
	Dr. Rohde says it is worth the effort to get educated and trained for doctors who haven’t been using clear aligners or who haven’t kept up on the changes with the treatment. Training is a crucial factor for success for general practitioners because dental school barely touches on the subject. “We learned enough to know that there is something called orthodontics, and that’s about it,” Dr. Rohde says.
	
	However, many patients are looking to fix their smiles. Dr. Rohde says the success of SmileDirectClub shows that to be true. Moreover, many doctors have an excellent rapport with their patients, and patients would prefer to stay in the general practitioner’s practice rather than leave to see an orthodontist.
	
	That said, Dr. Rohde still refers many adult cases to his orthodontist. Usually, it’s because he feels they are on the complicated side and need an expert overseeing the case.

	“Not that you can’t do complex things with clear aligners. But some cases are best treated with traditional ortho,” he says.

	Quinn notes that Align was first-to-market with Invisalign clear aligner technology 23 years ago and continues to be an innovator for the market. They have 952 active patents, per their website, and their technology has treated more than 7.5 million patients and they have provided hundreds of continuing education courses, including clinical support in every market speaking local languages. Align was the pioneer in clear aligner education and developing the biomechanics of tooth movement with clear aligners.
	
	“Now, with such heightened awareness from the consumer perspective, it is driving additional opportunity for the practices,” Quinn says.
	
	From a practical standpoint, Quinn says the most important thing to understand is not all clear aligners are created equal. In 2013, Align Technology introduced SmartTrack® material, designed specifically for tooth movement, which Quinn says was a significant change for the business and efficacy of Align Technology’s product.
	
	“The massive innovations that went into not only the material itself, but also the system and the architecture to support it were game-changers for our business. But they were also a game-changer for the clinicians and the outcomes for their patients,” Quinn says.
	
	Another critical change was when Align Technology made a significant investment in digitizing the front end of the process. Through the acquisition of the iTero product line in 2011, Align Technology fully digitized its clear aligner treatment process from start to finish.
	
	“That meant no longer having to use the goo to start analog and then convert to a digitized process. It’s digital through and through,” Quinn says.

	What to know about clear aligners and restorative work

	Zilles says with big suppliers such as Dentsply Sirona, Henry Schein, and Straumann in the mix with clear aligners, the potential exists to use clear aligners and Propel for movements prior to restorative work and pre-implant cases done in-house, or, for more advanced cases, referred out to a specialist. In the past, orthodontic treatment before restorative work wasn’t happening because treatment took up to two years with metal braces, and most dentists don’t want that long of lead time before placing a crown or implant.
	
	Zilles works with the clear aligner companies to accelerate timelines for treatment with Propel’s product line. With the help of Propel’s in-office product for micro osteoperforations, and their take-home vibration unit, VPro, clear aligner treatment is accomplished faster, and a general dentist can rotate teeth or create space needed for the restoration in weeks rather than years.
	
	“To be the best dentist you can be, you need not only clear aligners but also you need treatment to be five visits or less versus two years of orthodontic treatment,” Zilles says.
	
	According to Quinn, when doctors start with an iTero scan, they have new opportunities to provide their patients with a better understanding and view of their current and future smile.
	
	“We are working on digital communications tools, from visualization of treatment through in-depth treatment planning including restorative smile design to patient interaction and building the digital workflows to support however a doctor may want to practice,” Quinn says. 
	
	Moving teeth results in many benefits to the patient. Hygiene improves because it’s easier for them to clean their teeth. Occlusion improves to create better contact with the restoration, so their teeth last longer. Also, no matter how skilled the dentist is, veneers need replacing after 20 or 25 years. Patients who had their teeth straightened instead of veneers might get away with only wearing a retainer, Dr. Rohde says.
	
	“We often start an esthetic case by moving the teeth back to where they should be,” Dr. Rohde says. “When the orthodontic treatment is done, do a full esthetic evaluation of where the patient is, then. You might do a mix of bonding and veneers and whitening, too, but you’ve kind of idealized the situation first.”
	
	Dr. Rohde says everyone has patients looking for this kind of care. Clear aligners represent a clinical opportunity to care of your patients. They also broaden your treatment options. Many times Dr. Rohde idealizes the position of the teeth with clear aligners before restoring with porcelain. It not only restores function and occlusion to help the restorations last longer, but the restorations can also be more conservative.
	
	“In other words, maybe we’re doing conservative veneers rather than full wrap-around crowns,” Dr. Rohde explains. “Or, for lower anterior crowding, rather than chopping those tiny teeth down, we move them to a better position, and then that related restoration lasts longer.”
	
	Dr. Rohde says clear aligners used in combination with his laser and CEREC technology help him keep more of the cases in-house. He thinks other practices could, too.
	
	“With good training, everyone can do this,” Dr. Rohde says. “What we’re doing isn’t that hard. We just have the tools to do it.”

	The clear aligner innovations you should know about

	Zilles says some general dentists don’t want to get into orthodontics. Moreover, their patients don’t want to get treatment because they mistakenly believe it will take two years to complete. However, all the companies have unique ways to make clear aligner treatment more efficient and cost-effective for the practice, and more predictable and quicker for the patient. Some companies are expanding their sales force to train doctors on how to be more profitable using clear aligners to correct smiles. Some offer a low-cost tier for more straightforward cases, while others have options to make trays in their practice.
	
	“The biggest innovation, I believe, has been the different product offerings based on case difficulty,” Zilles says.
	In addition to their product features, Carsault says ClearCorrect is introducing innovative new technology to make it easy for GPs to use their product.
	
	“ClearCorrect was created by GPs for GPs in the first place. Our roots are here,” Carsault says.
	
	

Carsault says artificial intelligence (AI) will play a significant role in innovation for clear aligners as well as dentistry as a whole. He sees its impacts for clear aligners in the form of accurate treatment planning and connecting patients to the dentist. AI will help GPs treat orthodontic cases like a pro, as well as raise the patient consciousness with initial assessments about what can be addressed with the treatment.
	
	“AI is already everywhere in our daily life as a consumer. It is what is going to support the market moving forward,” Carsault says. “It will not replace the dentist; it will elevate the game of the dentist.”
	
	Align Technology has the most data available from past cases and uses AI and machine learning to predict how teeth will move using the Invisalign system. With more than 7.5 million cases to pull from, Align Technology has a lot of data to drive the accuracy of their treatment plans, help improve outcomes, and fuel further innovation. Quinn says recent new product launches for Invisalign First and Invisalign treatment with mandibular advancement were driven from decades of experience and data.
	
	“The extensive data generated by AI and machine learning gives that clinician confidence that the treatment plan and the Invisalign system is going to produce that outcome in the end,” Quinn says. “That advantage helps us drive the future innovations of our products to have more applications for different types of malocclusion that are showing up in the practices every day.”
	
	Invisalign First treats young and growing children with mixed dentition. AI technology recognizes erupting teeth and dentition and is used to build clear aligners to manage tooth movement through those growing stages. In Q3 of 2019, the Invisalign system was used to treat more than 130,000 teenagers and children as young as seven with their system through the doctor. They have treated almost two million teens and young patients in their history.
	
	“The innovation is there. There is an available appliance for those growing children and teenagers,” Quinn says of Invisalign First.
	
	With mandibular advancement, Invisalign aligners have wings included to address Class II malocclusion. Now, Quinn says 70 to 80 percent of all malocclusions can be treated with the Invisalign system.
	
	“AI helps drive those innovations and broadens our capability and efficacy to treat more complex types of malocclusion,” Quinn says.

  With good training, everyone can do this. What we’re doing isn’t that hard. We just have the tools to do it.” 

MS, DDS, who
	practices in Santa Barbara, Calif.

	
	SureSmile is also using AI to automate the routine tasks in treatment planning and preparation. For example, the SureSmile software is seamlessly connected to the Primescan intraoral scanner. They are bringing more tasks chairside from the central software, hosted on the cloud to allow dentists to show treatment simulations chairside. The goal is to produce seamless integration, which leads to faster turnaround times, enhances patient communication, and produces more efficient treatment timelines. Mondou says most of the time, it will be invisible to the practitioner.

	“Invisible, yes, except that they will do things faster,” says Dominique Mondou, who manages orthodontic platforms and marketing for Dentsply Sirona. “And there is a point where tasks that we’re doing in the lab will be done chairside because we’ve also made use of these technologies.”
	
	Plans for innovations at SureSmile include treatment monitoring with the auto-track software module as a way to engage more with the patient. For example, when patients come in, the team would rescan with Primescan in a few seconds and then compare the treatment plan with the actual position of the teeth to ensure the treatment is on track.

	“This helps the practitioner to track the treatment, so we get that GPS mindset of making sure we’re on the right track. And, on the other side, it’s also engaging with the patient and showing whether their treatment is right on target, or maybe that something is not happening,” Mondou says. “It’s a great communication tool.”
	
	Another significant innovation SureSmile is working on is to facilitate collaboration in Dental Service Organizations (DSOs) and group practices. With digital technology, the team can share cases to split between treatment plan and treatment execution. For example, if a DSO has an orthodontist and multiple general practitioners, the GP can have the specialist validate their treatment plan and handle the execution themselves.
	
	“You can increase collaboration and leverage your resources in a large, multi-practice group,” Mondou explains. “This is an area where we’re working heavily, as we believe there will be more collaboration like this moving forward.”
	
	“Align works with a number of DSOs throughout the U.S. and Canada,” Quinn says. “We collaborate with our DSO partners and provide them with education and training on Align’s digital platform along with co-marketing activities and more to support their doctors and help them drive interested consumers to their dental practices for treatment.”
	
	Carsault also sees that innovation in the clear aligner space will center around patients. It will help dentists, but it will also educate patients in a simple way about what can be done to improve the form and function of their smile.
	“The patient needs to be in the center of what we are doing because, again, we are doing that for them,” Carsault says.
	
	Dr. Poole is working with Uniform Teeth, a clear aligner company based in San Francisco. The biggest differentiator with Uniform Teeth is its balance of technology solutions to provide doctor-led care.
	
	“We have a team of engineers that are working on proprietary trading and planning software. We have this whole vertical integration where you don’t have to put the pieces together,” Dr. Poole says. “We can focus as clinicians on providing that standard of care that we want to provide, and Uniform brings the ecosystem to us.”
	
	Uniform Teeth uses telehealth, and the platform centers around dedicated orthodontists from top universities overseeing in-office care. Patients use an app-enabled remote check-in every week.
	
	“We have the app and the monitoring so we can have fewer appointments. But, at the same time, our clinicians see four to five times more patients than a typical orthodontist, although still only seeing 16 patients a day. That is possible due to the incorporation of our technology in the integration we have, along with our team planning software,” Dr. Poole says.
	
	Another innovation Uniform Teeth is introducing in their national roll-out next year is the patient app. Their app integrates into the electronic health system, which is in-house and proprietary. They can capitalize on this by reducing the number of in-person visits. They switch the tray and send in a picture. Then the doctor replies about whether the case is tracking, and, if it isn’t, what to do about it.
	
	“There have been instances where patients lose the tray, or we need to adjust something, and these are tasks you can’t facilitate on all these other platforms, which is interesting,” Dr. Poole says. “We have our team of customer support and care teams that are there to engage with patients directly, monitor their care, and ensure they get quality dentistry.”
	
	Clinicians using the Invisalign system also have access to cutting edge software tools designed to make the process easier. The ClinCheck software provides a 3D digital plan from start to finish to provide seamless digital treatment planning.
	
	“Doctors using the Invisalign clear aligner system have access to Align’s ClinCheck software, a powerful and sophisticated tool that supports treatment planning and monitoring,” Quinn says.

	The clear aligner marketplace changes you should know about

	Dr. Poole thinks there are two primary challengers to the established brands. Some, for example, bypass clinicians. However, she does not think those challengers will succeed in the long run.
	


	“Moving teeth is very serious, and not having that health care oversight eventually is going to show the hazards involved with that,” Dr. Poole says. “To maintain their value, established brands will have to continue to educate patients about the value of having that in-person care and what that means.”
	
	The second type of challenger embraces clinicians. Some target the entrepreneurial dentist and help them manufacture the aligners and providing treatment planning software. The battle there is that clinicians want to control and prefer to switch it, so they control the treatment plan, Dr. Poole says.
	
	“They’re going to have to shift and give more control to the clinicians,” she says.
	
	Dr. Poole says understanding the risks and downsides of both, as well as the benefits of the systems, is essential to the next movement in clear aligner therapy. Clear aligner companies need a treatment plan, to manufacture the aligners, and give control to clinicians for individualized care. Uniform Teeth is capitalizing on all of these.

	“Everything’s centered around the orthodontist and that patient care. So I think our type of interest is going to be more challenging to the brands that exist, and it’s going to bring something different. That is not already out there,” Dr. Poole says.
	
	Another influence of the many competitors is that the way clear aligner patients communicate with their dentist might change. In the direct-to-consumer (DTC) model, many providers are integrating the dentist early on, which can lead to a new type of treatment. Carsault sees that some form of this relationship has a place in the market and he is not going to fight it, but instead find ways to make it work for consumers and dentists.

	We need to realize that 50 is the new 30, and the patients are going to have these teeth for their entire lives. We can fix this today, and you can have straight teeth for the next 50 or 60 years.”

, vice president sales,
	Propel Orthodontics

	“In the future, you will see that the DTC model is going to stick around. That’s the model that patients want. So, this is also on us to be creative and bring some solutions to our dentists for them to provide the right services,” Carsault says.

	Mondou believes there is a significant market for the DTC organizations to treat uncomplicated cases for an expected price for a patient that maybe would never go to a dental office because they think it’s too expensive. While he recognizes that orthodontic associations are challenging that clinical approach, the market is there. Mondou says as a manufacturer, Dentsply Sirona has a responsibility to offer a solution to clinicians.
	
	“We see ourselves as empowering professionals and giving them the tools to be efficient and to deliver good care,” he says. “If there is a market that needs to be addressed this way, we need to look at it and provide tools, solutions, software, and devices to enable professionals to address that market.”
	
	Mondou sees that DSOs are best equipped to address this market because of their efficiency and operation model. Digital technology allows them to leverage expertise in a much more efficient, even disruptive way across the country and multiple disciplines.
	
	“I think they have a strong value to offer to the market,” Mondou says of DSOs.
	
	Also, Mondou says that because the medical and health care business is becoming fully digital, it will transform how it is done and how people behave. He compares it to how banking has changed from brick-and-mortar into coffee shops where you can do everything online. Likewise, the health care business is becoming more consumer-driven, and digital technology is transforming how they handle it.
	
	“So, as a manufacturer, we need to be the one partnering with these organizations, partnering with the professionals and helping them adjust to that and deliver the right solution to the patient,” Mondou says. “We look at it as a win-win partnership with the professionals.”
	
	Quinn thinks one of the benefits of having more competition is the heightened awareness it creates around clear aligner therapy. He sees a tremendous amount of untapped potential for doctors, their patients, and Align Technology, the most massive 3D printing operation in the world, with more than 454,000 Invisalign clear aligner trays produced per day.

	Quinn says a clear differentiator for Align Technology is the Invisalign brand.

	In the end, the doctor has to choose. He advises clinicians to understand the differentiators from one plastic to the other. Also, the platform drives the system and how well it’s integrated to deliver patient outcomes, as well as the support needed.
	
	“The thing that matters most is that the patient outcome is exactly the way it should be,” Quinn says. “This happens through a combination of our advanced treatment planning, doctor education, SmartTrack technology, and consumer marketing to build awareness and drive demand to the doctor’s office. We strive to be the best possible partner to our doctors and provide them with the right resources to help their patients and grow their practices.”
	
	Carsault is excited about the new competition entering the clear aligner space because it creates more discussion around clear aligners and treatment plans. He says it will create more market for everybody.
	
	“We have to acknowledge that we didn’t even scratch the surface off the addressable market in North America,” he says. “So, we are super excited to see that all together. We are going to bring more discussion, innovation, and more value proposition for patients.”

	What you should know about choosing a clear aligner partner

	Dentsply Sirona, the largest manufacturer of professional dental products and technologies, acquired OraMetrix and its SureSmile technology in March 2018. Dominique Mondou, vice president traditional orthodontics and OraMetrix, manages platforms and marketing of orthodontic products for Dentsply Sirona. Mondou says there are three things about clear aligners clinicians should be asking themselves:
	
	1.  How does treatment planning work?
	2.  Do you have control over how the teeth move, and will it achieve what you want?
	3.   Who’s the partner that’s going to help me implement that into my practice?
	
	Mondou says the ability to predict the before and after workflow, and the outcome are essential considerations for any clinician choosing a clear aligner partner. Also, it is vital to understand how you deliver the movement of each tooth.
	
	“I like to compare it to driving in a place you’ve never been. You might have a fantastic car, but if you get a bad GPS, you end up lost or losing time and maybe not getting where you wanted to go,” Mondou says.
	
	Mondou says treatment planning relies on the concept of “garbage in, garbage out.” In other words, the better the treatment plan, the better the treatment execution will be. Excellent treatment planning can result in a faster treatment or one where there is less refinement necessary at the end. In practical details, he says patients often ask how we approach the treatment planning, “So, do you have fewer attachments than we do now?
	
	“SureSmile is known for that. A lot of our heavy users comment about it,” Mondou says. “Because we know quite well the biomechanics and the treatment, we can reduce the number of attachments, and the attachment is the less esthetic part of the treatment.”
	
	Align Technology’s SmartForce attachments are small, tooth-colored shapes that are bonded to the patient’s teeth before or during their Invisalign treatment.
	
	Attachments engage with the Invisalign aligners to deliver forces to the teeth to provide the optimal orthodontic tooth movement.
	
	Align explains that in order to move teeth with clear aligners predictably and effectively, especially roots, you need attachments to achieve the desired movements. Invisalign clear aligners fit smoothly around the SmartForce attachments, so they’re barely noticeable.
	
	The second thing Mondou recommends is looking at how much control you have over the treatment, so you can deliver the quality of care that you want. However, being in control means different things to different dentists.
	“A specialist might want to be in control of the degree of rotation of that tooth, the exact details. For somebody else, being in control might mean, ‘If I have a question, I need support to back me up,’” Mondou says.
	
	Having a dependable partner is the third vital consideration per Mondou. He says at SureSmile, their philosophy is to provide you technology that enables you to do things you might not do otherwise. So while the most advanced specialists can use their products, they also can help educate and guide a general practitioner to provide quality care they might have referred out before.
	
	“And it goes from training the doctor on the software and the treatment planning tools to the clinical builds to helping the assistant treatment coordinator, and even how well they integrate that process into the regular process of the practice,” Mondou explains of the partner support Dentsply Sirona offers for GPs.
	
	

Mondou says training and maximizing the use of technology is in the DNA of the company. He says it is an essential thing to have superior technology backed by expertise, but training users to maximize the system is also vital.
	
	“We are using more and more solutions to share knowledgeÂ­Â­-from one-on-one eLearnings to large events that are focusing on maximizing the utilization of the system. So, we have a very broad range,” Mondou says.
	
	Align Technology agrees that training is crucial. They would also say what type of treatment planning and educational support your clear aligner partner provides to support you and your practice is key.
	
	There are four areas general practitioner Dr. Jeff Rohde suggests you consider when selecting a clear aligner supplier or partner, which include price, technology compatibility, educational opportunities for you and your team, and support.
	
	When it comes to price, Dr. Rohde says it is essential to understand how your partner will charge you and what is-and what is not-included in that fee for each case. It is also essential to understand if your technology is compatible with the clear aligner’s system or if you will need to invest in new equipment to submit cases.
	
	Additionally, it is crucial to understand what kind of training you will get, not only on the company’s technology but also evaluating occlusion and what to move when correcting smiles, too. Dr. Rohde suggests you find out if there is an opportunity for the staff to receive training, too, because they will be hands-on with much of the process.
	
	“The fourth thing would be support. Do you have someone there when something goes wrong, you have questions, you need to expedite something, or something’s not working?” Dr. Rohde says.

Our experts share what they know about the current state of clear aligners, what innovations have changed the game, and what is happening in a competitive landscape that is host to big names in dental and disruptive new technologies. With new approaches and new players for clear aligners, what is the clear path ahead?

Clear Aligners: The clear path ahead

	You did it. You registered and invested to attend a trade show for the benefit of your career, practice, and patients. Well done, you. But, what now?
	
	As it turns out, a lot of things. Preparing for a trade show can help you make the most of your investment. We spoke to experts about what you should be doing in the time leading up to your show and during it, as well as common mistakes to avoid.

	Clinicians should remember why they chose to attend the show and then, focus on attaining those goals, according to Jason Goodchild, DMD, Vice President of Clinical Affairs for Premier Dental Products Company.
	“Ask yourself, ‘Why do I go to these shows?’” Dr. Goodchild says.
	
	Clinicians should ask themselves this question because the need to travel to shows is not the same in 2020 as it was in 1999, Dr. Goodchild says. In the past, attendees needed to go to the shows to buy a lot of stuff and get a lot of continuing education (CE) credits. Now, it’s possible to do that without attending a trade show.
	
	To get the most out of the show, it’s important to identify why you wanted to go in the first place. The social networking that occurs at tradeshows is one way of doing business that is hard to replicate in other arenas. There are tremendous social networking opportunities at a show, Dr. Goodchild says.
	
	“There are fantastic opportunities to bring large groups of people together,” he says. “And the booths and the exhibit hall, they’re just awesome.”
	
	Some dentists like to use products that “feel good in their hands.” However, this mindset can lead to getting stuck in a rut and missing out on new material and equipment improvements. Seeing how other people do things and the latest products that you haven’t tried before can help dentists expand their horizons. A trade show shines in this area, Dr. Goodchild says. Moreover, the samples you collect there allow you to find out what else feels good in your hands.
	
	“There are so many opportunities to try new things and have your eyes opened about what else is out there, that maybe the shows can help us break out of that mold a little bit,” Dr. Goodchild says.

	Kim Miller, RDH, BSDH, finds balancing the different types of programs, such as education, exhibit hall time, and social events a challenge. There is always so much to do and see and so many courses she would like to attend, she says. Miller’s overall strategy is to divide her time between sessions and the exhibit hall. She takes morning or early afternoon classes and then hits the exhibit floor in the afternoon.

	“Plan ahead; otherwise, you wander around and waste time,” Steve Jones, Co-Chair of Roots Summit, a global endodontic meeting, agrees. “Decide what you want to accomplish before you get there so you can make the most of your time while you are there.”
	
	Janis Moriarty, DMD, is President of the Massachusetts Dental Society and past General Chair of Yankee Dental Congress held annually in Boston at the end of January. Dr. Moriarty recommends people go through the program book as soon as it is available, either in print or online.
	
	“It’s much more of an exciting and fulfilling experience if you have a plan of attack before you get there,” Dr. Moriarty says. “For someone that’s never been before, the size of the building and the number of courses and events available can be intimidating.  Doing a little homework ahead of time will help once you get onsite.”
	
	Miller agrees one of the most important things to do before the trade show is to review the catalog. She looks for intriguing course topics and ads for new equipment or services she is interested in, which she earmarks so she can visit that booth.
	
	“My advice is to be selective with the courses you choose and, as I mentioned, divide your time between courses and exhibit hall. Go to a two or three-hour course, then hit the exhibit floor for a couple of hours or vice versa,” Miller says.

	Look for CE opportunities and educational programs

	One of the most significant committees for the meeting is Programming, which begins planning the CE component two years before the meeting, says Dr. Moriarty, who is a private-practice dentist in Winchester, Mass., just outside of Boston and has worked at Yankee Dental  in various roles as a volunteer for more than  20 years.
	
	“There are many reasons to attend the meeting, but a necessity for sound practice is to get CE. We have a vast number of courses, and we look at trying to balance all the different specialties and general dentistry, as well as courses specific for auxiliaries,” Dr. Moriarty says.
	
	Another approach is to review what educational opportunities you haven’t taken recently, says Tina Clarke, RDH and instructor at Lane Community College in Eugene, Ore. She also suggests researching new ideas emerging within the profession, such as diagnostics or techniques.
	
	“The other thing, too, is the basic items that you have to have for state licensure within Oregon. If I can get those while I’m there, that makes it nice,” Clarke says.

	Miller recommends signing up early for the courses that are of the most considerable interest. Seats typically go fast for sessions in high demand, plus, she adds, you won’t pay late registration fees for the courses. Miller also advises dental professionals to make their hotel reservations early, as soon as the blocks open.
	
	“Hotels fill up fast, and you can always cancel your reservation, within limits, if your plans change,” Miller says. “To avoid disappointment, early sign up is the best.”
	
	“I look online and pick all the classes I want to go to and the big-name speakers or the topics I’m interested in learning. That’s going to be my background,” Dr. Goodchild says regarding the sign-ups. “I am going to get the CE I want to get."

	Map Out Your Exhibit Floor Time Beforehand

	Identifying any upcoming needs is always a good idea, Clarke says. If there are any big-ticket items that are needed, research them before the show.

	“For example, if I need to update my intraoral camera, I start looking to see what different features the companies have on their cameras. Then, I can develop questions for when I go to their booth for a demo,” Clarke says.

	Dr. Goodchild follows a similar approach, considering capital purchases he has coming up for the practice. He says for the significant technology purchases, such as digital scanners, trade shows offer a rare opportunity to comparison shop in-person.
	
	“It does allow you to see all of them at one time, put your hands on them, and find out which one feels the best,” Dr. Goodchild says. “And then when you zero in on it, you can contact the company, and the manufacturer can bring it to your office so you can give it a try.”
	
	Attendees should have an inventory of what they want to look at ahead of time, Clarke suggests. The trade show organizers often publish a map of the exhibitor floor and where the anchor booths will be. Having an idea of what the company’s booth number is can be helpful, especially if you don’t have a ton of time on the floor at the show, she adds.
	
	Miller locates the booths she wants to visit on the map and makes a note of the booth number. She then works her way through the exhibit hall systematically, starting with lower booth numbers and moving up.
	
	“This way, when I make an unplanned stop, I don’t lose sight of my goals, and I can get right back to the planned stops,” Miller says.
	
	Dr. Moriarty notes that the Yankee Dental Congress has an exhibit guide at the back of the program book. Also, a custom app is available two weeks before the meeting that has the “meeting at your fingertips.”
	
	“You can certainly take a peek at companies you might want to see. Also, you can take advantage of some of our marketing programs where you spend a certain amount of money and get a certain amount back and other incentives to do some shopping,” Dr. Moriarty explains.
	
	“I don’t think you should want to walk around the exhibit floor blindly,” Dr. Goodchild says. “If I’m interested in seeing some things, I’d like to know that they’re there and then make a bit of a plan.”

	As the seasoned attendee could probably tell you, there are definitely things to avoid while perusing a trade show. Our experts added their own advice on common mistakes and how to avoid them.

	Not Having a Plan for the Exhibit Floor and Booth Time

	Just as having a plan is a definite ‘do’, not having a plan is a certain ‘don’t’.

	Trade shows are the place to see the equipment in-person that you are interested in or want to know more about, Jones says. Find out where those are and make sure that you target those booths during those times.
	
	“Too many doctors come without a plan, end up wandering around and buying something that they stick in the accessory drawer and never pick up again,” he says. 

	When visiting exhibitors, it’s good to have specific questions to ask people and to take advantage of your time with them, Jones says. Don’t assume there’s nothing to be learned from someone who isn’t a dentist; there are a lot of experts who have a lot to offer in the booth, he adds.

	At busy booths, Clarke says to be sure to have questions ahead of time because the exhibitors are trying to serve as many people as possible. You want to get the information you need while respecting the exhibitors’ and other patrons’ time.
	
	“If you are prepared to pay at that moment as well, that will expedite everything, too. You can leave the show, and the vendor can ship what you want off to your office,” Clarke says.
	
	Dr. Goodchild admits that there is some fun to strolling around and window shopping. However, if something is needed for the office, you need to know what is available for you to see in-person to determine which ones you want to consider.
	
	“And then potentially making an appointment for a rep to come to my office to try it out,” Dr. Goodchild says. “Or, if they do have a crazy show special, is there a way to ‘buy it and try it’?”

	Wardrobe Malfunctions, Going Hungry, Getting Cold

	Almost anyone can tell you trade shows involve lots of walking, so choosing the right shoe is imperative. Clarke admits she has made a mistake choosing something cute over something practical, and her feet paid the price for it.

	“Sometimes we want to get super dressed up, and we have on our high heels. Then, you’re trying to scooch and hurry, and that may not necessarily be great for your feet if you’re on them for a long time,” Clarke says. “I’ve made those mistakes before. By the end, I was like, ‘Oh, I can’t look at any more stuff!’”
	
	Miller agrees that comfortable shoes are essential. She also says to bring a sweater or jacket, even if you are in a warm climate.
	
	“Dress in layers. The rooms are always cold,” she advises.
	
	Another important consideration is whether there is food offered on the show floor. Clarke says if there is, sometimes you can pull double duty and eat lunch while you look at things. Also, take advantage of sponsored lunch events, too.
	
	“If you know that you aren’t going to have that [lunch], make sure you have snacks in your bag that you can munch on,” Clarke says. “It’s important because it’s hard to make purchasing decisions when your feet hurt and you’re hungry.”
	
	Dr. Goodchild attended the Star of the North in Minneapolis in 2019 and appreciated a tactic they had for combining socializing and shopping on the exhibitor floor at the end of the day when everyone was ready to go home. They gave attendees a reason to stick around for a while, do some networking, and walk the exhibit floor, he says.
	
	“They did a happy hour from 5 p.m. to 6 p.m. with free beer and wine,” Dr. Goodchild said. “The exhibition floor was packed.”

	As important as it is to search out and try new products, trade shows are about networking with other professionals as much as anything else. It’s a good idea to use the buddy system, meaning meet up with a buddy or travel with one, Miller says.
	
	“These events are always more fun in pairs or groups,” she says. “Split up, go your own way, and then meet back up later to share what you learned, who you talked to, etc. Sometimes the exchange between colleagues is the best part of the event.”
	
	When Clarke goes to shows that are in different areas, she also arranges to meet with friends and walk the floor with them. This is a great time to network and talk with colleagues she doesn’t see often, she says. She also arranges to meet them at the social events or dinners sponsored by the show.
	
	“That’s some of the fun,” Clarke says. “Getting to experience those professional perks with your colleagues makes it possible to develop those friendships.”

	Skipping the social events at a trade show is a mistake, according to Jones. The social aspect of a trade show is an area that many attendees appreciate the most.  He highly recommends going to social events because meeting other doctors and specialists broadens your network and your knowledge base.
	
	“Social events are some of the most important parts of a trade show. You meet other doctors and exchange ideas in ways you wouldn’t get through any other forum,” Jones says.
	
	Social events are a vital part of the meeting, Dr. Moriarty agrees. She recommends using social media to determine if your friends and colleagues are going.
	
	“Nowadays, with all of those outlets, it’s really easy to both encourage people to go and be encouraged to go,” Dr. Moriarty says.

	Clarke, who is launching a new online platform called “Teacher Tina, RDH,” says education is vital to her. However, too much of a good thing can be a bad thing. Clarke follows a basic plan to do courses in the morning, the trade show floor at lunch, and then have the afternoon and evening for social events or sight-seeing.
	
	“The research I’ve done suggests that there’s not a lot of retention that happens after several hours of sitting and learning, you’ve already been getting a lot of brain work accomplished. For me, I’ll do my learning in the morning and have my fun in the afternoon,” Clarke explains.
	
	Breaking up the day with walks through the exhibits can help, Miller suggests. “I don’t want to sit all day, so, at a minimum after each course, I hit the exhibit hall floor for an hour or two between courses whenever possible,” she says of her schedule balancing strategy.
	
	One of the things organizers of Roots Summit want to provide attendees are clinical tips they can use in the operatory, Jones explains. However, they also build in lunch and breaks, with time to get to the floor and explore, as well. The idea is to balance between clinical learning and technology exploration.
	
	“The keynotes and breakouts are for clinical education. The exhibit floor is to talk to vendors and see the equipment that you want to see. However, you could get great advice from the reps on the floor, so don’t count that out,” Jones says.

	Attending smaller regional trade shows periodically can offer some variety from the bigger shows, Clarke says.
	“The product reps might have something a little bit different to offer, and some of the courses might be different, too,” Clarke explains. 

There are many things to consider before deciding to attend a trade show. Our experts offer advice on how to get the most out of the experience.

Show Do's and Don'ts: A guide to navigating the trade show floor

	Dental composite is a material that’s likely used every day in the practice. But what makes a composite the material used for dental restorations?

	Here, we define the chemistry of dental composites and how that chemistry affects your material’s characteristics. 

	Composite is a general term that means a material made of at least two other substances that, when combined, are stronger than they would be by themselves.

 The materials involved are usually hard fillers surrounded by a different material that binds them together in a solid-state. However, the elements that are combined do not lose their individual qualities, but instead, contribute their best characteristics for a particular use.

	Composites are found in a variety of items, such as sidewalks, furniture, and kitchen countertops. They can help restore teeth, as well.

	Dental composites use the same principles as the general term composite does. When thinking of the clinical or scientific definition of the compounds, it’s easier to think of resin composites as being comprised of three separate parts, says Nathaniel Lawson, DMD, Ph.D., division director of the Division of Biomaterials at the University of Alabama at Birmingham School of Dentistry. The essential components are dimethacrylate monomers, fillers (which are different types of glass or ceramics). The third component is composed of lesser additives, such as a coupling agent, pigments and initiators.  

	Each of these three parts has a job, Dr. Lawson says. The resin binds everything together and gives the composite flexibility while the filler’s job is to impart strength to the material. Meanwhile, the coupling agent’s job is to bind the filler and the resin together. 

	“The linker between the two is a coupling agent, usually a silane. Pigments make up the color of a composite. And photoinitiator are added to catalyze the polymerization of the resin. When blue light hits an uncured light-curing composite, the photoinitiators release free radicals, which cause the polymers to crosslink with each other,” Dr. Lawson explains. 

	However, the polymerization process needed to take resins from an uncured to cured state causes the polymer chains to get closer together. As they get closer together, the composite undergoes shrinkage, which can pull on the walls of a restoration, Dr. Lawson says. If a composite experiences too much shrinkage stress, it can lead to sensitivity and other complications in composite restorations for some patients. 

	Some composite materials are self-cured or dual-cured, Dr. Lawson says. The self-cure mechanism is one which initiates resin polymerization when two chemicals are mixed. 

	Dr. Rafael Bowen formulated the original dental composite in the early 1960s that was composited of silane-coated silica particles embedded into a bis-GMA (bisphenol A glycidyl methacrylate) resin. This bis-GMA resin was known as a dimethacrylate resin, as it had two methacrylate groups on either end that are capable of bonding with other methacrylate groups, which can be thought of as the “sticky ends of the composite.” A larger, stiff phenol group was present between the methacrylates which helps to prevent the materials from shrinking too much once it crosslinks. 

	Bis-GMA is still in use in dental composites today. There have been different dimethacrylates used in composites to impart different handling or mechanical properties to composites, Dr Lawson says. The most common are UDMA (urethane dimethacrylate) and TEGMA (triethylene glycol dimethacrylate). However, the essential parts of the composite remain relatively the same.

	“Nothing has changed that much as far as resins in the last 50 years, and that’s what makes all the resins similar to one another. It’s also why many materials from different companies are compatible,” Dr. Lawson explains. “You can use one company’s adhesive with another company’s composite because they are all methacrylate-based.”

	The compatibility of the dental composite to other restorative materials appears to be a valuable feature to clinicians. Companies tried to introduce dental composites that were not methacrylate-based, Dr. Lawson says. As a result, the non-methacrylate composite was not compatible with anything else.

	“Nobody wanted to use them,” Dr. Lawson says.  

	While there haven’t been many significant changes to what parts make up a dental composite, the ingredients of those parts have changed significantly over the years. One of those differences is the size of the fillers or the glass or ceramic particles inside the resin polymers. 

Traditionally, the size of the particles is how composites were categorized for many years. For example, the original composites were called macrofills after a few years because the particles were much larger than the newer composites, which were called microfills. 

	However, Dr. Lawson cautions clinicians not to define the size of the particle they are using based on what it says on the box. The reality is there is no standardization for what size a particle needs to be to have the label “microfill” or anything else. 

	“You don’t have to pass a test for particle size before writing microfill on your box,” Dr. Lawson says. “We can’t rely on a marketing definition that this composite is a hybrid or a micro-hybrid.”

	However, the size of the particle does matter. In dental composites, when the filler particles are smaller, they polish better. The challenge with small filler particles, however, is loading them into a composite in a high concentration without the filler particles agglomerating.   

	“The basic idea is,” Dr. Lawson explains, “if you have smaller filler particles, then when you polish it, the smaller filler particles that come off will leave surface irregularities that are smaller than what the eye can detect. If you have bigger filler particles and then you polish those, the larger particles pluck out, and then you have a surface roughness that is visible to the eye, and that's why they appear more rough or dull.”

	The hybrid dental composites, first introduced in the 1990s and mixed both large and small fillers, addressed these disparities in an attempt to get the best of both worlds. The particle sizes are still a significant factor in the development of dental composites. 

	Today, most dental composites are considered nanofills or nanohybrids, meaning the particles are so small, they are measured on the nanoscale. These dental composites capitalize on the principles of nanotechnology for mechanical properties and esthetics. 

	“Now most filler particles, even the ‘big’ filler particles, are only 1 or 2 microns, and most filler particles have sub-micron particles. So, it's not as critical of an issue,” Dr. Lawson says. 

	When talking to patients about composite, however, Dr. Lawson would emphasize that composites are tooth-colored materials that will wear and last the same way amalgam fillings do. There is no reason to say that composite material is inferior in mechanical properties to any other type of restorative, he says.

	However, dental composites are very technique sensitive, which is why Dr. Lawson believes amalgam fillings still have some perceived advantages over composite fillings. A perfect technique or rubber dam aren’t used to place an amalgam restoration. On the other hand, a composite needs excellent isolation and superior bonding technique to stand up to amalgam’s clinical success.

	“A composite done well, can hold up any day to an amalgam, in my opinion,” Dr. Lawson says. “The difference is that an amalgam done poorly is going to do better than the composite that was done poorly.”

 “What are composites?” compositeslab.com. Web. 12 January 2020. < 

http://compositeslab.com/composites-101/what-are-composites/

We take a look at dental composites from a chemistry perspective and how those chemicals work together to create restorative material.

What makes a material a dental composite?

	You have a lot of choices when it comes to dental composites. However, as many marketing companies will tell you and clinicians will agree, all composites are not created equal. Choosing the best material requires assessing the particulars of the case and the details of your composite.

	There are a few different ways to distinguish one composite from another. Some are more pertinent to performance than others. Let’s take a closer look at the types of dental composites and how they affect the potential outcomes for your restorations. 

	The two physical properties of dental composites that most clinicians evaluate are mechanical and esthetic:

 refer to the strength of the composite, how it wears in the patient’s mouth, as well as its bond strength and adhesion. In other words, how it performs physically. 

 refer to the finish and polish of the material, or, to put it simply, how it looks. 

	Dental composites have since been working to improve both of these areas in different ways since they were first introduced as a restorative material. Composites are made up of a few elements that, when combined, work together to make a flexible and durable dental material. One of the components of any composite is the fillers, which are typically pieces of glass or ceramic that are included in the resin matrix to give composite its strength. 

	At first, materials developers used the filler size to improve mechanical properties and esthetics. In the middle part of the 20

 century, the filler sizes in the first dental composites were much larger than they are today, coming in at 10-50 micrometers.

 These are macrofills. When it came to the first resin composites’ mechanical properties, bigger was better; these composites with large fillers were strong and durable. 

	However, macrofills did not finish and polish well. Moreover, the large particles were sometimes big enough to see with the naked eye and would sometimes chip off the resin holding them together.

 So began the push to develop composite resins with smaller particle sizes. 

	After the macrofills came the microfills with particle sizes that were smaller than 100 nanometers (nm). However, these composites introduced a new challenge. Microfills polished well and looked beautiful but were not strong enough to hold up to the bite forces in the posterior.

	Hybrids came next, which used a mixture of filler sizes to take advantage of macrofills’ strength and microfills’ esthetics. This mixture proved beneficial, and, as a result, many of the composites used today are a form of hybrid.

	However, the filler sizes today have decreased further on the nanoscale, with particles smaller than 20nm. Most composites today are nanocomposites. The most significant benefit of working with filler sizes measured on the nanoscale is that they capitalize on the principles of nanotechnology and its quantum effects. 

	The filler size of nanocomposites mimics the physical, chemical, mechanical, and optical properties that occur in nature.

 Their size means they can have different properties than if they were larger. The tiny fillers work together to create larger groups of materials, allowing the group to have different properties then they would as individual particles. This process improves nanocomposites’ esthetics and mechanical properties over their larger filler-sized composite predecessors.  

	Once reaching a satisfactory level of mechanical properties and esthetics, other characteristics influence what composite dentists choose. Some prefer a high radiopacity so that they can detect it on an X-ray in the future. The propensity for shrinkage is another consideration, although many materials today have stress blockers that help prevent sensitivity-causing material shrinkage of the material during polymerization. 

	Perhaps one of the most significant considerations when selecting composite is handling. 

	Dental composites are technique-sensitive restorative materials, especially compared to one of their popular antecedents, amalgam. A multitude of little steps make up composite placement technique, and perfecting the details of each is crucial. With method driving much of the success for a composite restoration, many clinicians prefer to use a composite that “feels good in their hands.” 

	There are three basic categories for handling properties in dental composites today, each with benefits to how they can be used for dental restorations:

: As the name implies, bulk fills require fewer layers to fill a preparation. Per the 

, their most significant distinguishing difference from the other types of dental composite is their increased depth of cure.

 Improvements in translucency for composite materials make it possible to cure a layer as thick as 4 mm. The translucency allows the curing light to penetrate deeper into the material. Furthermore, improvements in the bulk fill materials have also produced similar results to multi-layer composites for marginal gap widths and dentin adaptability.

: Flowables are also aptly named as their viscosity allows for increased fluidity for these dental composites. They are often packaged in a syringe with a small gauge needle to facilitate use in tight or small preparations.

 While the first flowable dental composites had reduced filler content to facilitate their physical properties, the flowable composites after 2010 have filler content similar to their more viscous composite counterparts. 

These composites are not defined by their layers or their viscosity, but instead for their intended use.Universal composites are designed to be the most versatile.  

	When to use the different composite types has a lot to do with the restoration you are treating. For example, you might use one type of composite for anterior restorations and a different one for posterior restorations.

	Many clinicians prefer to use bulk-fills in the posterior because they have a reputation for strength and durability, which makes them an excellent match for the bite forces there. Moreover, using fewer layers means fewer chances for technique problems, like air pockets and voids. Also, clinicians put bulk fills in the back because the translucency that increases the depth of cure produces esthetics better suited to areas less likely to be seen than prominent positions in the front.

	Flowable composites also have many uses in dental restorations. Their unique handling properties allow these composites to get into the small recesses of a preparation that their thicker counterparts cannot penetrate. Many clinicians use flowable to line the bases of their restorations, particularly deep preps in the posterior, because their self-leveling properties make them an optimal base. It also helps prevent voids when you pack a bulk-fill composite on top of it in a Class II restoration. Other uses for flowable composites, per the 

 include occlusal caries preparations, sealants for pits and fissures, minimally invasive Class II Restorations, as well as other noncarious lesions.

	Universal composites have the broadest applications. Formulated for use in anterior and posterior restorations, universals aspire to produce consistent results no matter where you place them or what adhesive system you use with them. They are also designed for indirect and direct restorations meaning they can bond to dentin or be used as adhesive primers for indirect restorative materials. In other words, you are meant to use universal composites for whatever you want, wherever you want. 

	There are many variables to consider when choosing which composite to use where for your restorations. In reality, however, the most influential variable is a personal preference.  Per the 

European Journal of Esthetic Dentistry, 

most clinicians are concerned with chair time and the difficulty of achieving proper esthetic results.

 Moreover, the researchers suggest that success is more in the manual skills of the clinician and mastering the techniques that will simplify placement.

	“In this profession,” the authors write in the article, “success should not be measured solely by exceptional results, but rather by a good everyday standard with regard to time management and limiting long-term risk.”

	[1] Lavigne, Courtney. “Dental Composites: Types and Recommendations.” Speareducation.com. 18 January 2017. Updated in January 2018. Web. 15 January 2020. < 

		[5] “What’s So Special about the Nanoscale?” nano.gov. Web. 14 December 2018. < 

https://www.nano.gov/nanotech-101/special

			[6] Van Ende, Annelies & De Munck, Jan & Lise, Diogo & Meerbeek, Bart. (2017). Bulk-Fill Composites: A Review of the Current Literature. 

https://www.researchgate.net/publication/316524305_Bulk-Fill_Composites_A_Review_of_the_Current_Literature

			[7] Agarwal, Rolly Shrivastav et al. “Evaluation of cervical marginal and internal adaptation using newer bulk fill composites: An in vitro study” Journal

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4313481/

			[8] Baroudi, Kusai and Jean C Rodrigues. “Flowable Resin Composites: A Systematic Review and Clinical Considerations” 

Journal of clinical and diagnostic research : JCDR

	[9] Shaalan, Omar Osama et al. “Clinical evaluation of flowable resin composite versus conventional resin composite in carious and noncarious lesions: Systematic review and meta-analysis” 

		[10] Devoto, Walter & Saracinelli, Monaldo & Manauta, Jordi. (2010). Composite in everyday practice: How to choose the right material and simplify application techniques in the anterior teeth. The European journal of esthetic dentistry : official journal of the European Academy of Esthetic Dentistry. 5. 102-24.

A Guide to Selecting Dental Composites

	There are many options for luting indirect restorations, two of which are used by many dentists-glass ionomers and resin cement. 

	Let’s review the differences between the two materials. 

: Glass ionomers are a mixture of glass and natural acid, usually fluoroaluminosilicate glass and polyacrylic acid. The material sets as part of an acid-base reaction that occurs when you mix the powder and liquid.[i] They are known for their ability to bond to the hard tissue of the teeth and the fluoride they release for a long time after placement.[ii]
		
		Per 

, clinical applications are varied for these materials. They can be a liner or base for a direct restoration or even as a full restoration for primary dentition. They can also be used as a fissure sealant. For luting and bonding, glass ionomer cement uses include cementation of bridges, crowns, bridges, inlays, onlays, and orthodontic brackets.[iii]
		 

: Resin cement is a mixture of glass and polymer resin material. The materials are usually self or dual-cured resins after phosphoric acid etch and rinse step. However, there are also self-adhesive versions that eliminate etching by adding phosphoric acid into the material. They are known for their excellent bond strength and durability. Some resin cements release fluoride, but not as much as glass ionomers.[iv]
		
		Per the 

Journal of the Canadian Dental Association

, resin cement in indirect restorations are the best for non-metallic restoratives, like ceramic and resin composite materials. They are also used for cementing resin-bonded fixed partial dentures and can also save dislodged crowns when necessary. [v]

	Each of these materials have advantages and disadvantages in specific situations. Two general dentists explain the pros and cons of each material and the cases where each performs well. 

	Glass ionomers have a proven track record over a long time, says Jeff Lineberry, DDS, FAGD, is a general and cosmetic dentist who practices in Mooresville, NC. He also likes how they release fluoride. 

Fluoride release is one of the more beneficial features of glass ionomers, agrees Alex Kalmanovich, DDS, a private practice dentist in Laguna Beach, Calif.

	Another significant advantage of glass ionomers is that they are much more moisture tolerant than resin cement, Dr. Lineberry adds.

	“Typically, resin cement is a lot less moisture tolerant,” Dr. Lineberry says. 

	Additionally, cleanup is easy, and it doesn't require many steps to cement the crown, Dr. Kalmanovich says.

	However, its dependence on mechanical retention rather than chemically bonded adhesive cement could be a pro or a con, he says.

	“It's a con because it's not universally used for every preparation. If you have a very short or tapered preparation, it probably won't be a great cement for that restoration,” Dr. Kalmanovich explains.

	Some glass ionomers are soluble in water, especially during the initial setting of the matieral, which is another downside, says Dr. Lineberry. He also pointed out that it’s a weaker cement than its resin counterpart.

	“Another disadvantage is that some of them are acid-base reactions, and sometimes they have a lower PH when they are setting,” Dr. Lineberry says. “Some people have post-operative sensitivity, at least initially.”

	One of the biggest advantages of using resin cement is the way it interacts with the tooth thanks to its improved bond strength, Dr. Lineberry says. This characteristic of resin cement is particularly helpful when you are cementing a crown that does not have as much retention form. 

	“If there is not as much tooth there to hold on to, we can use resin cement to help the restoration hold onto the tooth,” Dr. Lineberry says. “In other words, resin cement provides a better bond between the restoration and the tooth.”

However, resin cement is also less moisture tolerant than glass ionomer cement. When using resin cement, the procedure is much more technique sensitive because the area needs to be kept dry, Dr. Lineberry advises.  

We compare the differences between these two materials and which ones work best for specific applications