Since its creation in the 18th century, dental posts have evolved to benefit both clinicians and patients.
The computer, believe it or not, was conceived by English mathematician Charles Babbage in 1823.1 It looked nothing like today’s computers, of course, but it was the first, even though his project was never completed. Italian inventor Antonio Meucci is credited with developing a design for a talking telegraph or telephone in 1849.2 That telephone, of course, bears little resemblance to today’s communication devices.
But predating both of those technologies was the dental post. French physician Pierre Fauchard, widely considered the father of modern dentistry, published LeChirurgien Dentiste in 1728, which was the first publication to describe the use of dental prostheses, including dental posts.3 Like computers and telephones, posts are vastly different today.
History
Since its creation in the 18th century, posts have evolved. Bernard Weissman is a name synonymous with dental posts. Weissman, a Holocaust survivor, was born in Poland and came to the United States after World War II.4 He got his start in dentistry as a technician in Brooklyn, New York, during the 1950s. He founded the company Whaledent International in 1971 and was its president for the better part of 2 decades.4 In 1988, he acquired Dentatus, a Swedish firm known for its Classic Posts, and soon established the company’s global headquarters in Hawthorne, New York.4 His daughter, Nita Weissman, president of Dentatus Implant Division, reflects on her father’s inventions.
“He invented the first standardized post in 1962,” Nita Weissman says. “It was considered the first chairside endodontic post that didn’t require taking an impression and going through a laboratory.”
Weissman saw a need for something easier and more convenient for dentists.
“Before, you needed a laboratory, and it was a lengthy procedure,” Nita Weissman says. “The dentist couldn’t do it themselves in office, and he saw an opportunity and a way to make the prefabricated post and use it in the office, and it took off like wildfire.”
Dentatus had always piqued Weissman’s interest because it featured a tapered, anatomical apex. That feature allowed extra length and support without compromising additional tooth structure. When Weissman acquired Dentatus, one of the first things he did was change the reamer system, making the post passive. He also added surface texturization to make the post-and-crown procedure more efficient and aid esthetic masking. He rebranded this as the Dentatus Surtex Post.
“The idea of a cast post/core that goes inside of a nonvital tooth goes back to the 1700s,” dental industry consultant Norman Hicks adds. “Fast-forward to the prefabricated metal posts. There are several kinds of these. There are active and passive; parallel and tapered; and even threaded posts.”
Need
“In the early 1980s, a couple of dentists (Reynaud and Duret) in France were losing way too many endodontically treated teeth to root fracture,” Hicks says. “That was the problem. If you ask any dentist, ‘When you think about the endodontically treated tooth, what’s the worst-case scenario?’ Root fracture.… After that, you got nowhere you can go other than an implant. So, wouldn’t it make sense then, to find a post that does everything a post is supposed to do without increasing the risk of root fracture?
“These two, working through Recherches Techniques Dentaires (RTD), a French manufacturer of Burn-Out Posts,” he continues, “looked at the materials that were available and being used in other industrial applications. Carbon fiber–reinforced composite had the best combination of high strength and a low elastic modulus, which was mechanically well tolerated by the compromised tooth.”
Beyond merely fulfilling the basic function of a post—providing support for void-filling material and crown—the advancement of post technology continues.
Evolution
Like computers and telephones, dental posts’ evolution has made them better, stronger, and less expensive.
“A lot of the companies started adding titanium posts to their portfolio, because nickel was a material that people had allergies to,” Nita Weissman says. “A lot of advances came through the use of composite in the ’80s. That was a big deal with using posts with composites as opposed to cements.
“Then the next big move was in the late ’80s,” she continues. “Fiber resin posts were the big change. Some of the first posts were made of black carbon, and then they made them white because carbon was a very unesthetic black in the anterior region. That was also a trend, to move away from metal posts to fiber posts. And because composites are so good, the breakage point on a metal post is different from a fiber resin post. The fiber resin post will tend not to break in the canal.”
“The scientific literature also shows that a failed fiber post reconstruction is far more likely to be retreatable, whereas metal post failures tend to be catastrophic,” Hicks adds. “The first generation was carbon fiber, patented in 1989, and introduced in the [United States] in 1995, [was] strong, and…did everything a post was supposed to do without predisposing the tooth to root fracture, and…everybody accepts that now. The difference is that they are not threatening to the tooth because of the difference in the elastic modus of the fiber post (18-75 GPa [gigapascals]) compared to metal posts (100-200 GPa). The drawback to the carbon fiber was that it’s certainly not any more esthetic than metal. At that time, when 95% of crowns were porcelain fused to metal, you really didn’t care what color the post is, as long as it holds the crown and core in place. But now we see a lot more all-ceramic crowns, and when used in the anterior region, there’s such a thing with a metal post show-through,” Hicks continues.
“The other drawback to the original carbon fiber post is that it was not radiopaque. However, RTD figured out a way to make a carbon fiber post radiopaque.
Then the floodgates opened in the late ’90s, with glass fiber posts and quartz fiber posts, which were esthetic and radiopaque with adequate strength and an elastic modulus even closer to that of dentin (18 GPa). So, it’s…a generational thing, and just about every manufacturer of posts and core build-up materials has introduced their own design of aesthetic post,” Hicks says.
Nita Weissman highlights the next noteworthy feature of Dentatus’s posts: sterility and traceability. The posts used on a given patient are easy to track in case their history needs to be examined.
“Rather than having a box with 15 posts, hanging out loosely in there, Surtex Sterile [posts] are offered in single-dose packs,” she explains. “And on the back of the package is the catalog number, the reference number, the lot number, the manufacturer, the material, the length, the diameter, and the expiration date. And it’s all repeated on top, so the doctor can keep this one in his file and use it as a reference.”
Like computers and telephones, dental posts have a long history, punctuated by innovation and advancement. And, like computers and telephones, dental posts will continue to evolve, to the benefit of endodontists and patients.
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