Long-term Clinical Outcome of Teeth Obturated with Resilon

1. Barborka et al, JOE 43:4 April 2017, 556-560

The primary objective of root canal treatment is to eliminate the etiology of pulpal and periapical disease and promote tissue healing.  Following cleaning and shaping of the root canal system, the hopefully pristine endodontic environment needs to be filled and sealed, both apically and coronally, to prevent bacteria and tissue fluids from re-contaminating the canals.

The root canal filling is a critical component of successful endodontic treatment.  The ideal filling material, as outlined by Grossman, needs to be biocompatible, dimensionally stable, bacteriostatic, easy to use and retrieve, and needs to effectively seal the canal.  Gutta percha (GP) has been the most widely used obturation material for over a century.  It fulfills most of Grossman’s criteria with the exception of sealability.  GP itself does not adhere well to the dentin walls and subsequently requires a cement interface to create a seal between the dentin and GP.  Various forms of zinc oxide/eugenol sealers have been used with GP over the decades resulting in long-term success rates over 85%.

The 1990’s, saw an explosion in endodontic technology and techniques enhancing our understanding of endodontic pathology and our abilities to reverse its effects.  New obturation materials and techniques flooded the market, each claiming to improve on tried and true gutta percha.  Many came to market with only limited in vitro research and testing – mostly to prove the material was non-toxic and obtain regulatory approval.  Most in vivo research unfortunately followed, not preceded, introduction to the marketplace.

Dentistry has continuously been in search of the ideal dental material that creates a bacterial impervious seal between our restorative material and the tooth structures.  We saw this first with enamel bonding and subsequently with dentinal bonding.  The monoblock concept of sealing the root canal system in three dimensions, from coronal access to the apical terminus, arose in the late ‘90s.

In 2004, Resilon emerged as a promising alternative to GP.  It was a polycaprolactone polymer containing bioactive glass and radiopaque fillers and was described as being a thermoplastic, polymer based, bonded root canal filling material.  The Resilon core material bonded to the resin sealer which in turn bonded to the dentinal wall, creating a monoblock and improved seal.  The early research showed equal or superior sealing ability when compared to GP as well as good biocompatibility.  There was even some evidence that there was improved fracture resistance with the Resilon monoblock.  Most of this evidence was in vitro and with time, in vivo research challenged the monoblock concept.  Ultimately, the best evidence to support the use of an obturation material must come from clinical studies which unfortunately were thin.  Early retrospective studies, from 6-25 months, showed Resilon obturation success rates in line with those of conventional GP/ZOE sealer obturation.

Barborka et al, JOE 43:4, in their retrospective, case-controlled study, looked at the long-term success of teeth obturated with Resilon.  They compared the success rate of Resilon and Real Seal SE sealer (RS) with that of GP and AH plus sealer (GP).  The 100 teeth included in the study (50 RS, 50 GP) were treated between 2007 and 2012, at the Texas A&M, graduate endodontic clinic.  Teeth included had no evidence of periapical lesions preoperatively, while postoperative endodontic results were satisfactory without any endodontic or restorative defects.  The GP and RS groups were matched as to patient age, gender, tooth type, and medical histories.  Success was defined as absence of clinical signs and symptoms and normal periapical tissues.  Failure was defined as clinical signs or symptoms and/or the presence of a periapical lesion.  The average recall times for the Resilon group was 5.8 years and the GP group was 6.6 years.

The authors found that 88% of the GP obturation group were successful while only 56% of the Resilon group were successful.  They also found that in the failure cases, the RS group was associated with more external resorption in the periapical areas.

While these results need to be confirmed with further studies, it points to one of the major problems we see in endodontics today, namely the pursuit commercial gain through the rushing of new materials into the marketplace without adequate research to confirm their efficacy.  New is not always better and as dental professionals, we need to demand long term evidentiary support before exposing our patients to new methods or materials.

Note:  Resilon was removed from the US market in 2014.

 

About the Author, Dr. Howard Bittner, DMD, CAGS

Dr. Bittner was born and raised in the Surrey / Langley area. Following his pre-dental training at Simon Fraser University, he received his Doctor of Dental Medicine from the University of British Columbia in 1982 and his Certificate in Advanced Graduate Studies in Endodontics from Boston University’s Goldman School of Dental Medicine in 1995.
Dr. Bittner was in private practice in general dentistry for 11 years in Langley before his Endodontic specialty training. He has been practicing Endodontics since 1995.
In his free time, Dr. Bittner loves to participate in a variety of sports including most recent, golfing! He also enjoys being a grandfather to 3, which if you ask him is just the best!

On July 12, 2017, posted in: News for Doctors by

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