April 1, 2012
by Douglas L. Lambert, DDS, FACD, FASDA, ABAD
Our desire to satisfy a patient’s esthetic and restorative goals may pose a multitude of challenges for us as practitioners. Today’s dental consumer is well-educated based on a variety of sources, and their dental IQ has never been higher. Access to information via the media — print, television, and the Internet — has lead to a virtual “esthetic tsunami.” This newfound knowledge base obtained by our patients should be viewed as a positive, not as a negative, and offers us the ability to continue the education process in helping them to reach their goal.1 The myriad of esthetic and cosmetic procedures available to patients continues to grow as a result of rising demand for these services by a health-conscious society seeking to maintain or recapture their youthful appearance. From the profession’s standpoint, the numerous treatment modalities available to us have never been greater. This can translate into a multitude of options such as whitening, tooth repositioning, metal-free alternatives, composite bonding, ceramic veneers and crowns, and lesser or non-invasive procedures.
However, one of the biggest challenges we face has nothing to do with restorative options, but involves the impact that our ever-changing economy has placed on our patients and practices. Our ability to be nimble and creative in our treatment planning has never been more paramount. The skill to look “outside the box” can help us create an environment where we can meet the esthetic and restorative goals for the patient, while balancing the economic impact. One such method available is to meld the use of direct fiber reinforcement and composite resins into a conservative, non-metallic esthetic solution to a restorative dilemma.
Fiber reinforcement is not a new phenomenon. It’s origins spring from various sources such as aerospace, sporting goods manufacturing, bullet proof vests and the automotive industry to name a few. In dentistry, it has a history of both direct and indirect applications by enhancing the physical properties of other materials including the reinforcement of denture bases and orthodontic retainers, splinting of periodontally diseased and traumatized teeth, endodontic posts, large span temporary bridges, bonding of cracked teeth, and replacement of a missing tooth as a fixed prosthesis.2-14
Direct composites have also had a long and storied history in dentistry, but not without their share of concerns. It has been nearly sixty years since Buonocore conceived of bonding to enamel with the introduction of acid etching,15 and though the resin-based materials of that period were quite inferior to those currently available, issues related to the enamel/dentin interface and handling characteristics, as well as the clinician’s skill, are still keys to the success or failure of a composite restoration. Many times composites offer dentists the most simple and cost-effective manner in which to create an esthetic restoration because they are conservative by nature, have the flexibility to restore only what is missing, and may be used as a transitional or long-term restoration. As a result, the combination of direct fiber reinforcement coupled with composite resins can offer the practitioner conservative, esthetic, metal-free alternatives to add to their restorative armamentarium. This marriage can be especially beneficial to the patient when the topic of replacing a missing tooth is addressed. With over 20 years of placement, the author has found that the use of a direct composite, fiber-reinforced fixed prosthesis can offer an economically-sensitive solution to restorative and esthetic challenges in both the anterior and posterior.
The fundamentals of the direct fiber-reinforced composite bridge are as follows:
— Pontic is created using direct composite resin
— Fiber reinforcement added for improved physical properties and longevity
— Conservative preparation design
— Excellent esthetics
— Expands treatment planning options
— Easily repairable (if necessary)
A healthy, 53 year old female presented for the replacement of a missing maxillary right first premolar (#5). We discussed her esthetic and restorative goals and evaluated all her fixed and removable options including a dental implant. She chose a direct fiber-reinforced composite bridge due to the conservative nature of the restoration and economics.
1.8 cc of 2% Carbocaine with 1:20,000 Levonordefrin was administered and the amalgam restoration on the mesiocclusal of the adjacent second premolar (#4) was removed. Removal of the existing MO amalgam yielded an ideal slot prep for the placement of fibers on the distal abutment (Fig. 1). The occlusal and mesial proximal aspects were also beveled on # 4 using a 40 u diamond. The abutment preparation on #6 was made on the lingual with a 100 u round nosed diamond, creating a cup-shaped prep and the distal proximal of # 6 beveled as well. The preparations and gingival tissues were cleansed with 5% sodium hypochlorite on a disposable brush to remove residue from the site (Fig. 2).
The tissue-contacting half of the pontic (pontic button) was created with a gingival-shaded body composite of choice by rolling the material in a gloved hand and pressing it onto the gingival ridge (Fig. 3). It was manipulated using brushes and composite instruments to form lingual, facial and proximal contours prior to curing with an LED light source (Demi Plus — Kerr Dental) for 40 seconds. The pontic button was removed from the ridge and only the tissue-contacting side polished with abrasive cups and points (Astropol — Ivoclar/Vivadent). Take care to create proper gingival embrasures to allow for a floss threader to pass through the mesial and distal once it is bonded into place. Set aside the pontic button for now (Figs. 4 & 5).
A total-etch technique was employed on the preparations using a 30+% orthophosphoric acid for 15 seconds — the first five seconds on enamel only, then onto dentin for the remaining 10 seconds. Rinsed with a water spray and dried with light air pressure being careful not to desiccate the dentin. A fifth generation bonding agent (Prime & Bond NT — DENTSPLY/Caulk) was applied over all prepared and etched surfaces according to manufacturer’s directions, and then cured for ten seconds (Figs. 6 & 7). A slot was cut into the occlusal surface of the pontic button using an inverted cone diamond to create room for the fibers, and spot-tacked to the abutment teeth using a highly filled flowable resin (Grandio SO Heavy Flow — VOCO), then cured thoroughly for 40 seconds. A second layer of the enamel/dentin adhesive was also applied to the slot portion of the pontic for 15 seconds, air thinned and cured for 20 seconds (Fig. 8).
A piece of dental floss was used to help determine the length and pathway for the fibers. It is important that the fiber bundle remain within the preparation margins (Fig. 9). The fibers, which are pre-impregnated with resin, were removed from the sealed package and cut to length with a #15 blade (GrandTEC — VOCO) (Fig. 10). A bead of the flowable composite was syringed into the prep on #4, across the slot in the composite pontic button, and onto the lingual prep on #6. he fiber bundle was placed into the prep areas and adapted to the slot preparations using a composite instrument lubricated with an unfilled bond resin (Heliobond — Ivoclar/Vivadent). Additional body composite was injected over the uncured flowable and fibers, and “ironed” into the preps until a smooth surface is created. It was then cured with a visible light source for 40 seconds from the buccal, lingual and occlusal aspects (Figs. 11 & 12).
The occlusal half of the pontic was fashioned by first re-etching the composite pontic button for 15 seconds, then rinsing and drying. This was followed by the application of the dentin bonding agent, air th
inned and cured for 20 seconds. A small increment of the flowable composite was syringed over the pontic and spread over all surfaces using a brush, air thinned, then cured for 20 seconds. The incisal shade of composite was applied, building up the cusp tip and overlapping onto the occlusal and lingual surfaces (Figs. 13-16). Refinement the pontic shape, including a non-functioning lingual cusp, was completed using instruments and brushes, then cured thoroughly for 40 seconds from the buccal, lingual and occlusal. Final shaping, occlusal refinement, and polishing was accomplished using 12-bladed, spiral shaped carbide burs (Axis Dental) and abrasive cups and points (Figs. 17-20). Final views of the completed direct fiber-reinforced composite bridge from the occlusal and buccal aspects (Figs. 21 & 22).
When considering the multitude of options available to us for esthetic restorative cases, the use of conservative measures in our treatment planning is always a prudent measure. Creating a solution that is conservative, functional, esthetic, and economically-sensitive should be paramount in order for us to assist our patients in meeting their goals. The use of direct composite resin, coupled with fiber reinforcement, offers an excellent tool to help solve these esthetic dilemmas in our ever-changing economy.OH
Douglas L. Lambert, DDS, FACD, FASDA, FASD, ABAD graduated from the University of Minnesota Carlson School of Management in 1980 and the University of Minnesota School of Dentistry in 1984. He is a lecturer, author, and independent dental consultant for various manufacturers, and is partner in an esthetic-based practice in Edina, MN, emphasizing cosmetic, comprehensive, and sports dentistry. Reach Dr. Lambert at email@example.com or view his lecture schedule at www.dentalteamconcepts.com
Oral Health welcomes this original article.
1. Lambert DL. Esthetic motivation with vital tooth bleaching. Signature. Winter 2001.
2. Ayad MF, Maghrabi AA, Garcia-Godoy F. Resin composite polyethylene fiber reinforcement: effect on fracture resistance of weakened marginal ridges. Am J Dent 2010; 23(3):133-6.
3. Belvedere, PC, Turner WE. Direct fiber-reinforced composite bridges. Dent Today 2002; 21(6):88-94.
4. Freilich MA, Meiers JC, Duncan JP, Eckrote KA, Goldberg AJ. Clinical evaluation of fiber-reinforced fixed bridges. J Am Dent Assoc 2002; 133(11):1524-34
5. Chen Y, Li H, Fok A. In-vitro validation of a shape-optimized fiber-reinforced dental bridge. Dent Mater 2011; 27(12):1229-37.
6. Sekhar LC, Koganti VP, Shankar BR, Gopinath A. A comparative study of temporary splints: bonded polyethylene fiber reinforcement ribbon and stainless steel wire + composite resin splint in the treatment of chronic periodontitis. J Contemp Dent Pract 2011; 12(5):343-9.
7. Guler A, Kurt M, Duran I, Uludamar A, Inan O. Effects of different acids and etching times on the bond strength of glass fiber-reinforced composite root canal posts to composite core material. Quintessence Int 2012; 43(1):1-8.
8. Kathuria A, Kavitha M, Khetarpal S. Ex vivo fracture resistance of endodontially treated maxillary central incisors restored with fiber-reinforced composite posts and experimental dentin posts. J Conserve Dent 2011; 14(4):401-5. 11.
9. van Heumen C, van Dijken J, Tanner J. Five-year survival of 3-unit fiber-reinforced composite fixed partial dentures in the anterior area. Dent Mater 2009; 25(6):820-7.
10. van Heumen C, Tanner J, van Dijken, et al. Five year survival of 3-unit fiber-reinforced composite fixed partial dentures in the posterior area. Dent Mater 2010; 26(10):954-60.
11. Uribe F, Meiers J, Nanda R. Fixed retention of congenitally missing maxillary lateral incisors using a chairside, prefabricated fiber-reinforced composite bridge. World J Orthod 2008; 9(4):349-54.
12. Cagidiaco M, Goracci C, Garcia-Godoy F, Ferrari M. Clinical studies of fiber posts: a literature review. Int J Prosthodont 2008; 21(4):328-36.
13. Schmitter M, Rammelsberg P, Lenz J et al. Teeth restored using fiber-reinforced posts: in vitro fracture tests and finite element analysis. Acta Biomater 2010; 6(9):3747-54.
14. Karaarslan ES, Ertas E, Ozsevik S, Usumez A. Conservative approach for restoring posterior missing tooth with fiber reinforcement materials: four clinical reports. Eur J Dent. 2011; 5(4): 465-471.
15. Buonocore MG. A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. J Dent Res 1955; 34: 849-853.