As an endodontist, I have bonded all my obturations the last two years. Recently, I did so on my daughter, Bianca. To me, if it’s good enough for Bianca, all my patients will be treated this way.
Gutta percha has been the traditional standard for endodontic obturation, even though it does not chemically bond to any sealer, does not bond to canal walls, and does not prevent the migration of bacteria in a coronal to apical direction. Gutta percha is wholly dependent on a coronal seal (bonded composite build up, for example) to prevent the apical migration of bacteria coronally to apically.
The three primary functions of a root canal filling are:
① To entomb most surviving bacteria
② To stop the influx of periapical tissue-derived fluid from reaching surviving bacteria in the root canal system
③ To act as a barrier, thereby preventing reinfection of the root canal (i.e., provide a coronal and apical seal).
Bonded obturation has the potential to achieve these functions if performed properly. Gutta percha simply does not. Bonded obturation is reliant upon removal of the smear layer with a liquid EDTA solution such as SmearClear (SybronEndo, Orange, Calif.).
Resilon Research (Wallingford, Conn.) introduced Resilon in 2003. RealSeal was licensed by SybronEndo to use Resilon technology. I have extensive clinical experience with RealSeal.
RealSeal is:
◆ A thermoplastic synthetic polymer-based root canal filling material
◆ Polymers of polyester
◆ Bioactive glass, bismuth oxychloride, and barium sulfate
◆ Overall filler content ~ 65percent by weight
RealSeal Sealer is:
● Dual-cure dental resin composite sealer
● Mixture of BisGMA, ethoxylated BisGMA, UDMA, and hydrophilic difunctional methacrylates
● Fillers of calcium hydroxide, barium sulfate, barium glass, and silica
●Total filler content in sealer ~ 70 percent by weight
RealSeal self-etching primer is:
■ Water
■ HEMA
■ Sulfonic acid-terminated functional monomer
■ Polymerization initiator
In addition, RealSeal is:
▲FDA-approved in the United States
▲Noncytotoxic
▲Nonmutagenic
▲Well tolerated and biocompatible
▲Nonallergenic
The core material bonds to the sealer. This bonds to the hybrid layer that is formed, creating an obturation that is continuous from the center of the canal to the resin tags in the dentinal tubules. The hybrid layer is responsible for the leakage reduction. RealSeal points look, handle, and can be retreated just like gutta percha. One does not need to change obturation techniques to use them. The material can be condensed laterally, and used with any warm technique except for carrier-based obturation since there currently is no bonded warm carrier-based product.
The material has been tested extensively in vivo and in vitro. Positive results verify manufacturer’s claims. In my empirical opinion, there is no credible evidence that the material does not perform as well as its developers claim.
Interestingly, several papers are less than favorable toward the material. To my knowledge, these papers have two authors in common. One such paper is entitled “Ultrastructural evaluation of the apical seal in roots filled with a polycaprolactone-based root canal filling material” Tay FR, et al. JOE, 2005 Jul; 31(7): 514-519.
A research paper should:
❚ Carefully explain its methodology
❚ Be conducted to exclude variables
❚ Have experimental groups evaluated by a blinded investigator
❚ Statistically evaluate results to eliminate bias
In my opinion, the above-mentioned research paper does not achieve these objectives.
The important points are simple. Bonded obturation is here to stay. It represents a significant advance compared to gutta percha. I encourage you to disregard the background noise and sound bites in papers that may not have clinical relevance. I want to “do unto others.” So, if I will do unto my daughter, Bianca, I will do unto all my patients. I welcome your questions and feedback.
Dr. Richard Mounce is in private endodontic practice in Portland, Ore. Dr. Mounce is the author of a comprehensive DVD on cleansing, shaping, and packing the root canal system for the general practitioner. The material also is available as audio CDs and a Web cast pay-per-view. He lectures worldwide and is a widely published author. For more information, contact Dr. Mounce via e-mail at [email protected]. Visit his Web site at www.MounceEndo.com.
