Replacement of a tooth with a fiber-reinforced direct bonded restoration Fixed Prosthodontics Ian E. Shuman, DDS Abstract Today's methods and materials for tooth replacement are multiple and varied. Modern materials now allow for highly conservative abutment preparations that can retain bonded single tooth replacement fixed prostheses. A case report is presented in which fiber reinforced with composite resin was used for placement of a three-unit fixed long-term provisional restoration, providing fracture resistance while achieving an esthetically pleasing, durable restoration.

Received: September 27, 1999 Accepted: December 20, 1999 GENERAL DENTISTRY MAY-JUNE 2000

In the past, tooth replacement has been accomplished with traditional fixed and removable appliance therapy. More recent approaches have used composite alone or in combination with other reinforce- ment materials. Strassler et al reported that treatment combining composite with wire, metal, and nylon grids and pins had the potential of creating shear planes and stress concentrations that would lead to premature failure. However, use of fiber set in composite resins resulted in an increase in the strength of the restoration. Recently, this new type of restorative material, fiber- reinforced composite, has been used successfully to treat a variety of restorative situations, including tooth replacement.28 Fiber-reinforced composite (FRC) can be described as composite materials formed from laminae, which are layers containing both fiber and matrix that are placed one on top of the other.11 It can be created from a variety of both composite and fiber materials. Alone, composite resin is a brittle material, incapable of withstanding prolonged occlusal forces, especially as an unsupported pontic. The addition of fiber to the composite matrix decreases the chance for failure and increases the overall strength and toughness of the composite. Ideally, fibers that reinforce dental resins should have the characteristics listed in the table.9 Many relatively new fiber reinforcement materials satisfy some or all of these desirable characteristics. They can be classified as glass fiber (Splint-It®, Jeneric/Pentron, Wallingford, CT;

800/243-3969; Vectris, Ivoclar, Amherst, NY; 800/533-6825; and GlasSpan, GlasSpan Inc., Exton, PA; 800/280- 7726) , polyethylene fiber (Connect, Kerr Dental, Orange, CA; 800/537-7123 and Ribbond®, Ribbond, Inc., Seattle, WA; 800/624-4554), and fiberglass (Kevlar®, DuPont, Wilmington, DE; 800/441-7515). Fibers can be further classified by their direction and weave, which can be unidirectional and braided (for example, GlasSpan) or multidirectional and woven (for example, Ribbond®. In an evaluation of fiber reinforcement materials, Christensen concluded that all fibers improved the fIexural strength and fIexural modulus of composite resin.10 Of the fibers tested, Ribbond® had the best ease Of use, did not splay when cut, and maintained its width after cutting.11

Ramos et al tested the physical (fracture) strength of Ribbond® embedded in a polymethyl-methacrylate bar. The results indicated an increase of 28% in the mean fracture strength of the bar. In addition, the bar never exhibited catastrophic failure due to crack propagation resistance because the Ribbond® stopped crack propagation, leaving the bar intact. Based on these findings, Ramos et al concluded that when provisional fixed acrylic resin restorations were reinforced with Ribbond®, a reduction in fracturing would result, increasing clinical success. Samazadeh et al reported that when a bisacryl composite restorative material (Provipont DC, Ivoclar) was reinforced with Ribbond®, the fracture strength was

Table. Characteristics of dental resin reinforcing fibers.

Strength The fibers should be able to support a significant load with minimal elastic distortion. Toughness A great amount of energy should be required to break the fiber. Water absorption The fiber should absorb a minimal amount of water. Optical properties With esthetic materials, the fiber should become camouflaged within the composite resin. Biocompatibility The fiber must be biocompatible to avoid toxic injury and of such a physical state to avoid a biologic response to physical irritation. Bondability The fiber should chemically bond to the resins so as to minimize the effect of interfacial shear- induced sliding or debonding between the fiber and the brittle resin material. Conformability The fiber should conform to and remain conformed to the underlying geometry or configuration of the teeth and the dental arch. Configuration of the fibers The configuration of the fibers should be such that the resulting fabric form is easy to use and should perform well in function. Manageability Manageability determines the ease of use that the dentist encounters in placing the material. Mode of failure The mode of failure should be such that if and when the fiber fails, there should be little if any chance of injury to the patient. increased significantly.12 When a crack did occur, it did not propagate beyond the polyethylene fiber. Miller and Barrick reported using Ribbond® in combination with composite to immediately replace traumatically avulsed primary and adult teeth.2 In this case, Ribbond® was selected because it had more desirable characteristics than other fiber reinforcement materials. In some cases, it is no longer required to replace a tooth using earlier, traditional therapies. With current adhesive restorative materials allowing for increasingly conservative tooth preparation, FRC has become an acceptable alternative. For the case being presented, a tooth is extracted and replaced in a simple, conservative, inexpensive method using fiber-reinforced composite. Case report The patient, a 70-year-old man, Le complained of a loose maxillary right central incisor (Fig. 1). The tooth had received multiple restorations including direct composite and a retention pin. Clinical and radiographic examinations revealed a supererupted maxillary right central incisor with external resorption of the root and a periradicular radiolucency extending further apically (Fig. 2). Heavy generalized deposits of calculus were present (Fig. 3). There also appeared to be periodontal destruction with associated gingival edema and purulence from the periodontal sulcus. The tooth in question exhibited Grade 3 mobility and was

Fig. 1. Supererupted maxillary right central incisor (tooth No.8). Note the purulent exudate from the crevicular gingiva and the associated periodontal destruction.

Fig. 2. Radiograph of tooth No.8 exhibiting external root resorption and virtually complete periradicular radiolucency.

the subsequent

rative

Fig. 3. Heavy generalized calculusdeposits demonstrating poor oralhygiene and lack of dental care. painful to palpation. The patient was told that the tooth would require extraction, periodontal defect would require correction, and the tooth would be replaced at that visit as well. Then, after sufficient healing of the surgical site, a more long-term restoration would be created. More traditional restotreatment options were ruled

Fig. 4. Tooth No.8 as a natural tooth pontic, bonded to the mesial of tooth No.7 with composite resin alone.

Fig. 5. At two weeks postextraction, a 3.0 mm section of Ribbond® Reinforcement Ribbon was bonded from tooth No.7 to tooth No.90

Fig. 6. The Ribbond® bonded to place in the Class III mesiolingual preparations of teeth No.7 and 9.

Fig. 7. Ribbond® "beam wrap" fiber wound around the horizontal layer and light cured.

Fig. 8. The restored lingual aspect of the pontic.

Fig.9. The restored facial aspect of the pontic with composite resin extended to the mesiofacial areas of the adjacent abutment teeth. Note the fiber material visible at the midline.

out because of a history of poor oral hygiene, the lack of adequate periodontal support, and the desire for minimal abutment tooth preparation. To replace the tooth, it was decided that fiber-reinforced composite would be the treatment of choice.

Clinical procedure

The maxillary right central incisor was anesthetized for extraction. Following extraction, the socket was debrided and irrigated with chlorhexidine 0.12% and the heavy calculus deposits were removed from tooth No.8 and the adjacent teeth in this area. A full thickness, buccal gingival flap was elevated and hydroxylapatite bone graft material (Osteograf®./N, CeraMed Dental, Lakewood, CO; 800/426-7836) was syringed into the socket. An absorbable gelatin sponge

(Gelfoam, Pharmacia & Upjohn Co., Peapack, NJ; 888/768-5501) was placed over the filled socket site and the flap was sutured closed. The root of the extracted tooth was sectioned and the crown portion was saved. The coronal pulp chamber was cleaned and filled with a dual cure composite resin, trimmed, and polished. The crown pontic was bonded to tooth No.7 with composite resin alone. A visible light cured periodontal surgical dressing (Barricaid®., Caulk/Dentsply, Mil- ford, DE; 800/532-2855) was placed and cured at the surgical site [Fig. 4) and the patient was released. At a follow-up appointment two weeks later, the socket appeared to be healing well and the crown pontic was sectioned from tooth No.7 and discarded. The maxillary right lateral and left central incisors were anesthetized and

er was used.

Class III preparations were made in the linguomesial surfaces of these teeth. Separate labial preparations were created on the faciomesial aspects of the abutment teeth. These preparations were necessary in order to increase the mesiodistal width of these teeth with composite and decrease the excessively wide pontic space. Retraction cord was placed in the gingival sulci of the abutment teeth and a premeasured 3.0 mm n piece of Ribbond®. was saturated with resin, blotted dry, and bonded into the Class III preparations with Herculite®. XRV (Kerr Dental), a hybrid composite resin (Fig. 5 and 6). Ideally, fiber reinforcement should consist of multiple layers in the horizontal span; however, due to severely limited occlusal clearance, only one horizontal layAdditionally, Ribbond®. "Beam

Fig. 10. Immediate esthetic correction of the visible fiber at the midline by the additioncomposite resin.

of Fig. 11.

ridge.

Fig. 12. Fig. 11 and 12. Six month postoperative examination of the fiber-reinforced composite b

Wrap“ fiber was saturated with resin, blotted dry, and coated with FloRestore®. (Den-Mat, Santa Maria, CA; 800/433-6628), a flow- able hybrid composite. It then was wrapped around the horizontal layer, compressed flat in the buccal-lingual, and light cured,

l facial layer and light

rity and esthetics (Fig. 11 and 12)

Discussion

t

utment d

ultiple appointments. thanson

ich relied solely on

st history with

upon

creating a rigid beam (Fig. 7). Renamel Hybrid composite (Cosmedent Inc., Chicago, IL; 800/621-6729), shade A-4, was placed on the lingual aspect of the Ribbond@-composite beam and light cured (Fig. 8). Renamel Microfill composite (Cosmedent Inc.), shade A-3.5, was placed on the facial, shaped, and light cured. Renamel Microfill in the incisal medium shade was placed as a finacured (Fig. 9) In order to create optimal esthetics, the fibers which were visible between teeth N 0. 8 and 9 were covered with additional composite resin, recontoured, and polished (Fig. 10). The entire prosthesis was taken out of occlusion in both centric and protrusive movements in order toreduce stress on the restoration. The patient was placed on a three month periodontal prophylaxis re care regimen. At a recare appointment six months later, the FRC bridge was examined and ap- peared to be functioning properly, maintaining its structural integ

The idea of using fiber as a rein- forcement material is an ancient one. One of the earliest recorded references to this technique is of biblical origin, describing how the Egyptians, building their cities and monuments, reinforced bricks of clay with straw, a fiber material.13 The conservative replacement of missing teeth using reinforcement is also not a recent innovation. Archeological discoveries of natural and artificial pontics bound to existing teeth with gold wire and gold straps have been reported in the literature.14 While these ideas remain unchanged, today's materials allow for permanentooth replacement with minimal to no tooth preparation. In the past few decades, conservative, fixed partial denture tooth replacement has been accomplished using a combination of various materials. Initially, pontics of acrylic resin denture teeth were bonded directly to adjacent teeth without additional reinforcement.15,17 Howe and Denehy bonded a cast metal framework of perforated plates with a porcelain pontic to the lingual aspect of abteeth; however, this require

18mIn a similar fashion, Na

and Moin fabricated an electroplate framework of perforated metal rectangular pads (commonly used in orthodontics) with a composite pontic and bonded the assembly to the lingual aspects of the abutment teeth.19 This prosthesis was easier to fabricate and could be completed in a single visit. Later, Livaditis and Thompson developed the etched cast resin bonded retainer, known as the Maryland Bridge.20 This prosthe- sis provided an actual resin to metal bond, an improvement over the perforated metal retainer whmechanical retention. In all of these cases, the acrylic or metal-composite bond was not sufficiently strong for long-term use and, due to these bond failures these techniques met with limited long-term success. In general, bonding a pontic fabricated of acrylic, composite, or the natural extracted tooth itself should be considered a short-term replacement. However, when an appropriate fiber reinforcement material is used, long-term success is more likely. The choice of material to reinforce composite resin should be based upon paclinical success. The use of Ribbond®, a polyethylene fiber, is based the clinical reports of tooth

replacement by Bredenstein and Sperber, Marcus, Miller, and Portilla, among others.21-24 Ribbond®. also has been described as being used for perio- dontal splints, strengthening removable prostheses, post and core fabrication, provisional and permanent bridges, denture repairs, and as a framework for composite onlays and crowns.2,21-

35

E.

Conclusion

This case report presents the successful replacement of an extracted tooth using fiber-reinforced composite therapy. Further investigation is needed to provide more long-term data on the use of these techniques.

Acknowledgements My appreciation to Dr. David Rudo for his research assistance. My thanks to the clinicians, researchers, inventors, and chemists who bravely explore the bounds and limits of the human capacity. Their creativity and genius have made the stuff of science fiction a joyul, dependable reality.

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Shuman, DDS, 442 Pamela 1.

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Author information Dr. Shuman is in privatein Glen Burnie, MD, and isclinical instructor in the department of restorative dentistry at the University of Maryland School of Dentistry. Address correspondence to: Ian

Road, Glen Burnie, MD 2106

Dr. Shuman will present his lecture, "Salvaging the Near Hopeless Periodontal Case Using Direct Composite and

Toronto 2000

References 1. Strassler HE, Haeri A, Gultz JP. New-generation bonded reinforcing materials for anteriperiodontal toosplinting. Dent Clin North Am 1999;43:123. 2. Miller TE, Barrick JA. Pediatric trauma and polyethylene reinforced composite fixed partial denturmethod. Can Dent J 1993;59:252-256. 3. Nixon RL, Weinstock A. An immediate-extraction anterior single-tooth replacement utilizing a fiber-renforced dubridge. Pract Perio Aesthet Dent 1998; 10: 1 7 -26. 4. Trushkowsky RD. Polyethylenefiber reinforcement for interrestorations and porehabilitation. Dent Today 1997;Dec.:66-71. 5. Shannon A. Fiber-reincomposite bridge ite

6. Meiers JC, DFreilich MA, Goldberg AJ.Preimpregnated fiber-reinforced prostheses. Part II. Direct applications: Splfixed partial dentures. Quinte768. 7. Freilich MA, Duncan JPMeiers JC, Goldberg AJ. Preimpregnated, fiber-reinprostheses. Part I. Basic rationale and complete-coveraand intracoronal fixed partial denture designs. QuinteInt 1998;29: 689-696. 8. Altieri JV, Burstone CJGoldberg AJ, Patel AP. Longitudinal clinical eval- uatioof fiber-reinforced composite fixed partial dentures: Astudy. J Prosthet1994;71:16-22. 9. Rudo DN, Karbhari cal behaviors of fiber reinforcement as applied to tooth stabilization. De1999;43:7-36. 10. Christensen G. Reinforcement fibers for splinting teeth. CRA newsletter 1997;2111. Ramos V Jr., Runyan DA, Chris- tensen lC. The effect of plasma-treated polyethylenfiber on the fracture strengthpolymethyl methacrylate. J Prosthet Dent 1996;76:94. 12. Samazadeh A, KugelHurley E, et al. Fracture strengths of provisional restorations reinforced wplasma- treated woven polyethylene fiber. JDent 1997;78:44. 13. The Jerusalem Bible. Jerusalem: Koren PublishJerusalem ltd.;1969:67. 14. Ring M. Dentistry. An illustrated history. New Harry N. Abrams1985:29,36,45. 15. Ibsen Rl, Neville Krestorative dentistry. PhiladeCo.; 1974. 16. Stolpa JB. An adhesive technique for small anterior fixed partial dentures.1

17. Jordan RE, Suzuki M, SGratton DR, Gwinnett JA. Temporary fixed partial denturesfabricated by means of the acid-etch resin technique. A report ocases followed for up to thre

ills PS,

f 86 e

r e

ork. J Prosthet Dent

. Metal-

.

J Prosthet Dent

lass-

t

Dent

er

d Educ Dent 1996;17:182-

t a

Soc Ped

ion site

sthet Rest

, . CRA newsletter

rosthet Dent 999;82:233- 236.

s

st and

th:

Esthet

n

-59.

l

lab

t:3. S, Riis DN,

ce

et Dent 1999;81 :262-

,

:14-28.

in:

z

etic -22.

int

od Rep 995;July:46.

years. JADA 1978;96:994. 18. Howe DF, Denehy EG. Anteriofixed partial dentures utilizing thacid-etch technique and a cast metal framew1977;37:26. 19. Nathanson D, Moin Kreinforced anterior tooth replacement using acid-etch- composite resin technique. J Prosthet Dent 1980;43:408- 412. 20. Livaditis GJ, Thompson VPEtched castings: An improved retentive mechanism for resin- bonded retainers.1982;47:52-58. 21. Bredenstein J, Sperber G. Ribbond® reinforced Artgbridge. Dental Spectrum (Germany) 1998;111 :11-18. 1 22. Marcus SJ. An indirect/direccombined approach for a reinforced fixed bridge. J N JAssoc 1994; Winter:13-16. 23. Miller TE, Margalit S, CreamTJ. Emergency direct/indirect polyethylene-ribbon-reinforcedcomposite resin, fixed partial denture: A case report. CompenContin190. 24. Portilla MP. How to construcnew type of anterior deciduous bridge. J SoutheasternDent 1994;2: 14-16. 25. Kois jC. Esthetic extractdevelopment: The biologic variables. Contemp EDent 1998;2:10-18. 26. Christensen G. Post and corestate-of-the-art1998; 22:2,3. 27. Marcus SJ. Interim estheticrestoration in conjunction with anterior implants. J P1

28. Hornbrook DS, HastingJH. Use of bondable fiber reinforcement for pocore build-up in an endodontically treated tooMaximizing strength and esthetics. Pract PerioDent 1995;7:33-44. 29. Iniguez I, Strassler H. Polyethylene Ribbond and fixed orthodontic retentioand porcelain veneers: Solving an esthetic dilemma JEsthet Dent 1998;10:5230. Kau K. Provisionasplinting on tapered abutment implants using Kerr Mfg. Co.'s Herculite XRVcomposite and Ribbond reinforcement ribbon. Dent Lab Prod 1993;Sept/Oc31. Srimai Morgano SM. An in vitro study of the fracture resistance and the resistance and the incidenof vertical root fracture of pulpless teeth restored with six post- and-core systems. JProsth269. 32. Miller TE, Connelly ME. Guidelines for the salvagerepair, and conversion of existing prostheses. Contin Educ J Dent 1993;4533. Nash R, Kau K. Reinforcing composite resA restorative alternative. Compend Contin Educ Dent 1994;15:554-560. 34. RadG. Beyond the Maryland bridge. Amer Acad CosmDent J 1996;12:1835. Ribbond, Inc. Constructing a reinforced composite periodontal splusing Ribbond bondableribbon. Dent Pr1