Bioceramics Offer Functionality, Efficiency, and Promise for the Future

Dental materials are thousands of years old. Research suggests that beeswax is among the oldest dental material used.¹ Evidence of beeswax fillings were found on a 6500-year-old human mandible.¹ There is evidence of Etruscan dentists using gold dental bridges from approximately 700 to 600 BC, and they were also the first culture to test the use of dentures and false teeth.² During China’s Tang dynasty from AD 618 to 907, Chinese dentists were using silver paste, a precursor to the 19th century’s adoption of early amalgam.³

Materials and technology have only continued to improve. Today, dentists regularly use materials such as composite, zirconia, and other bioactive bioceramics. Bioceramics are somewhat new and deserving of a place in the endodontist’s armamentarium.

Terminology

Before getting too deep into the practicalities of bioceramics, it’s important to understand some definitions. First, what exactly are bioceramics?

“Bioceramics are inorganic, ceramic materials (refractory polycrystalline compounds) used in orthopedic medicine and dentistry,”Alex Fleury, DDS, MS, explains in his e-book Bioceramics: Redefining Endodontics. Dr Fleury is a faculty member at Real World Endodontics, which partners with Brasseler to provide continuing education services.“There are various categories of bioceramics used for various applications. They are highly biocompatible materials that (by design or selection) should have similar physical characteristics to the tissue that they are replacing or repairing. They are chemically stable, noncorrosive, and…able to withstand interfacial interactions with surrounding organic tissue.”

“Ceramics are typically made from inorganic, nonmetallic materials that have properties that make them suitable for use in dental applications,” Marco Canonico, North America manager at Angelus, adds. “The term ‘bioceramic’ refers to a type of ceramic material that has been designed and developed for use in biological applications. One of the main similarities between bioceramics and other restorative materials is that they are all used to repair or replace damaged or missing tooth structures. However, bioceramics have several unique properties that make them particularly suitable for use in dental applications, such as calcium silicate–based dental materials, which exhibit bioactivity [because] they have the ability to interact with natural mechanisms to heal a lesion and enhance regrowth of damaged dental-related tissues.”

Bioceramics refer to more than 1 endodontic material. “Bioceramics is a very broad category of materials,” Ryan M. Walsh, DDS, MS, says. Walsh is a diplomate of the American Board of Endodontics and the and owner of Advanced Endodontics of Texas in Keller. “In general, bioceramics are anything that’s a ceramic material that’s put into the body. So that can range anywhere from things [such as] artificial hips and joints to porcelain crowns to porcelain orthodontic brackets to endodontic sealer. In the endodontic sense, it often refers to a bioactive type of sealer or canal obturation material. They’re very unique, and they have some interesting properties that are different [from] other materials in dentistry and are incredibly well suited for life as an endodontic product.”

Bioceramics are also well suited for use in damp environments, such as someone’s mouth. “They’re hydrophilic, so they’re very moisture tolerant, and as a matter of fact, they need moisture to set,” Dr Walsh says. “So that’s highly advantageous, because in dentistry we’re working in a moisture-rich environment, and many of our materials are hydrophobic. These materials are very technique sensitive. Bioceramics are also dimensionally stable. So unlike many things in dentistry that shrink with time, bioceramic materials do not. Some sealers and putties have shown slight expansion over time, being a very advantageous property to have as a dental material.”

It’s also necessary to understand the difference between bioactive and bioceramic. Bioceramic simply means that materials can be used with living human tissue. Bioactive implies the stimulation of healing properties. “They stimulate the body to heal,” Dr Walsh observes. “We’re no longer just plugging holes or filling cavities. We’re stimulating the body to heal.”

But what does it mean for the body to heal with bioactives? Is it a barely noticeable trace or a full-on, evident regrowth? “Somewhere in between,” Dr Walsh explains. “We’re not regenerating teeth per se, but what we’re doing is more than just trying to fill a hole or fill a void. We can place the material into these environments or into these holes that will stimulate the body to heal the native tissues at that site. So if there was an area of bone loss at the root tip, these sealers or putty-like materials have been shown to stimulate the body to heal bone and ligament at that site.”

Ultimately, these materials are especially useful for endodontists’ needs. “They have been used in dentistry [for] root repair material, apical filling material, perforation, filling bone defects, [and] as endodontic sealers and treatments on vital pulp, [such as] pulpotomies and direct pulp capping,” Canonico says.

Usage

In endodontics, bioceramics are essential. “There are several categories of bioceramic material: for root canal obturation, for endodontic repair in specific cases of lesions and vital pulp therapies, and for intracanal medication,” Canonico says.

“Bioceramics have a broad application,” Dr Walsh adds. “As an endodontist, I think of them as root canal filling materials or repair materials for perforations or resorption, things of that nature. But there [are] also bioactive composites that can be used for areas of deep decay to help prevent recurrent decay. If you’re just talking general bioceramics, they’re used in porcelain and zirconia crowns on a daily basis.”

Bioceramics can be used in several different endodontic applications. “Bioceramics have become…necessary in most major endodontic procedures by using the different bioceramic materials to address those needs,” Dr Fleury says. “They can function as cements, root repair materials, root canal sealers, and liners. This all has the advantage of enhanced biocompatibility, the potential to increase root strength following obturation, and…antibacterial properties, which aid in postoperative healing and bone regeneration.”

Misconceptions about bioceramic use exist and necessitate explanation. “One misconception about many new dental materials is that because [we’re] using the latest, greatest material, the body will naturally heal to it,” Dr Walsh says. “That’s not necessarily the case, because although they give us a higher likelihood of stimulating true healing, we still have to do our jobs as dentists and remove the decay or remove the bacteria at those sites to allow the bioactive materials to do their job.”

Some misconceptions are related to how bioceramics are named, causing confusion for users. “[In] literature, we can find bioceramic material with other nomenclatures, and it causes some misconceptions [in the] market. Calcium silicate, mineral trioxide aggregate (MTA), biomaterials, hydraulic cement, and other names refer [to] this class of material,” Canonico says.

Additionally, in its informational booklet Restorative Endodontics, Brasseler notes that usage misconceptions pervade. “We have often heard that bioceramic sealers were difficult to retreat,” it reads. “This is easily solved when using a hydraulic bonded obturation, which uses a single gutta-percha cone and does not require condensing and creates a bond between the sealer, canal, and the gutta-percha. Gutta-percha can easily be removed if a retreatment is necessary. You could not use it during warm vertical condensation techniques. This has been overcome with a BC Sealer material like EndoSequence HiFlow because the formulation was made to be more flowable due to its smaller particle size and has a lower viscosity when headed.”

The Future

Bioceramics continue to evolve and improve, to everyone’s benefit. “This is probably one of the more rapidly growing areas of dentistry,” Dr Walsh says. “With ProRoot MTA back in the early 1990s, we had a stagnation until about 2009 when Brasseler’s BC Sealer came out. And since 2009, things have really taken off. Now there are many different bioceramic materials available on the market. Now we even have bioactive composite resins. The field of bioactivity is really growing at an astounding rate, and we’re continuing to improve and refine our products to make them even more user-friendly and even more bioactive.”

“Since 1993, when we had the first notice about this kind of material, the development was in great evolution, and this material is the most studied [in the] dentistry field since then,” Canonico adds. “Angelus, for example, has a patent for at least 3 new materials based on bioceramics under development.”

Dr Fleury looks forward to advances in bioceramics’ functionality. “Advances in obturation efficiency and clinical success are now possible as a result of the improvements in sealer technology,” he says. “In this era of minimally invasive dentistry, minimal hard tissue loss should be a fundamental goal of endodontic treatment. The properties of bioceramic sealers allow a more conservative approach to endodontic shaping, preserving more natural tooth structure. Bioceramics are ideal in that they exhibit advanced physical and chemical properties essential to endodontic success. In addition, these materials are now the material of choice for direct and indirect pulp capping and root-end filling. Restorative endodontics is setting a new standard of care as root canal therapy becomes an integral part of the restoration of a tooth.”

Where will that evolution and improvement be seen? “I think cost is going to be a big driver,” Dr Walsh says. “If we can continue to increase the bioactivity and decrease the cost, allowing for improved esthetics and handling long term, I think that’s the ideal pathway to move forward. And we’re progressing down that pathway, but we haven’t hit the peak yet.”

Dental materials continue to advance and improve. Bioceramics are relatively new, and their evolution is an exciting world for endodontists. “We know that bioceramics is a new category of material, and in the near future, not just endodontics will benefit from it,” Canonico says. “Moreover, there is a demand for materials that have the ability to be bioactive rather than inert materials.”

References

1. Bernardini F, Tuniz C, Coppa A, et al. Beeswax as dental filling on a neolithic human tooth. PLoS One. 2012;7(9):e44904. doi:10.1371/journal.pone.0044904
2. The whos and whys. University of Maryland School of Dentistry. Accessed March 25, 2023. https://www.dental.umaryland.edu/museum/exhibits/online-exhibits/gold-gems--glory/the-whos-and-whys/
3. Bjørklund G. Fra tannamalgamets historie [The history of dental amalgam]. Tidsskr Nor Laegeforen. 1989;109(34-36):3582-3585