Over the years, one of the most challenging restorations to place has been on a tooth presenting with a Class IV fracture. Dentists have universally experienced difficulty in providing a long-lasting restoration that exhibits all of the color properties necessary for a successful shade match, as well as harmonious texture and polish. Due to their past experiences, many clinicians have regarded a direct-bonded Class IV restoration as a temporary solution. They will often advise their patients that the affected tooth will require a porcelain restoration as the definitive treatment.
However, there has been a flurry of progress in the research and development of composite resins during the first decade of this millennium. New techniques have been introduced, and an improved protocol has been developed in the clinical environment to maximize these advances. Because of this, there should no longer be a reason to regard composite resin restorations as temporary or substandard. It is, however, important to update your knowledge on the properties of the composite resin material that you are utilizing in order to consistently create beautiful restorations. In order to realize long-lasting results, adhering to protocol is even more important. The following case study represents a typical emergency appointment dealing with a fractured central incisor in an adolescent patient.
Diagnosis and Treatment Planning
|Figure 1. Facial view of fractured upper central incisors.||Figure 2. Lingual view of fractured upper central |
|Figure 3. Note the band of incisal translucency.||Figure 4. Vit-l-escence (Ultradent Products) enamel-enhancing shades.|
|Figure 5. Vit-l-escence basic enamel shades.||Figure 6. An undulating (scalloped) margin was prepared to create an invisible margin once the microhybrid composite resin was placed.|
|Figure 7. Opaque Snow was used for the lingual layer.||Figure 8. Dentin shade A1 was used to replace the missing dentin.|
A 15-year-old male was seen in response to an athletic trauma inflicted upon teeth Nos. 8 and 9 (Figure 1). Incidentally, a majority of Class IV fractures occur in this age group.1,2 The mesial-incisal angle of tooth No. 8 was fractured at the incisal one third, and only involved the enamel. Tooth No. 9 was fractured in the middle one third at the mesial-incisal as well as the distal-incisal angle and involved both dentin and enamel (Figure 2). A standard periapical radiograph was taken to verify that there was no pulpal involvement or fracture of the root or surrounding structures.
There was enough sensitivity to temperature changes to necessitate performing the procedure under local anesthetic. Prior to beginning the procedure, the resin shades were chosen while the teeth were still hydrated. In this case, a narrow translucent incisal zone was evident, accompanied by the incisal halo (Figure 3). To deem this restoration an aesthetic success, these subtle nuances would need to be duplicated, and thus we chose Vit-l-escence (Ultradent Products) for this case. In most situations, this requires only 2 shades: one dentin and one enamel shade, in conjunction with a universal lingual opaque shade that prevents intraoral show-through. The dentin shade required for this restoration, as determined by utilizing the specific resin shade tab, was A1. This composite resin system, as well as other "super systems" offer numerous enamel shades. However, most of the enamel shades are in fact enamel enhancing shades, which are generally not used on a daily basis. In the Vit-l-escence system, the enamel enhancing shades are designated as "Trans" shades; the true enamel shades are designated as "Pearl" shades—of which there are only 4 (Figures 4 and 5).
Of the 4 Pearl shades, the authors use only 2 of them based on whether the patient has bleached his or her teeth or not. If the patient has bleached, Pearl Frost is used. If the patient has not bleached, Pearl Neutral is used. Since our patient had not bleached his teeth, Pearl Neutral was used for the facial enamel layer, while Opaque Snow was used as the universal lingual opaque layer.
Preparation and Composite Resin Placement Protocol
Local anesthetic (3% Isocaine plain [Septodont]) was administered and the fractured teeth were prepared with a long star-burst shaped bevel (48L bur [Brasseler USA]) (Figure 6).3-5 Teflon tape would have been necessary to cover the enamel of the adjacent tooth if an interproximal contact had been present. In this case, the adolescent had diastemas present, which were left open in anticipation that future orthodontic treatment would be able to properly position the teeth.
Beginning with the right central incisor, the teeth were restored. Tooth No. 8 was etched (UltraEtch [Ultradent Products]) and bonding agent applied (PQ-1 [Ultradent Products]). To ensure an invisible margin, both the etchant and the bonding agent were applied well beyond the fracture line in a gingival direction. Longevity of the restoration depends upon utilizing a maximum amount of the remaining facial enamel. The increase in surface area improves the bonding anchorage value of the restoration to such an extent that this restoration should rival the cosmetic life of any all-ceramic counterpart. Since the fracture in tooth No. 8 only involved the enamel, and occurred at the line of translucency, no dentin shade or lingual opaque shade was needed. Therefore, only Pearl Neutral was used, thus preserving the translucent zone as well as continuing the incisal halo of the natural tooth.
|Figures 9 and 10. After placing Pearl Neutral as the facial layer, adjusting and polishing. The completed aesthetic and strong composite resin restorations.|
After preliminary shaping of No. 8, the enamel and dentin surfaces of No. 9 were prepared with UltraEtch and PQ1 bonding agent, again extending in a gingival direction well beyond the fracture line. The lingual enamel layer was placed using a universal lingual opaque shade (Opaque Snow). It is important to note that it was left short of the final distal and incisal edges of the tooth, allowing for the creation of a thin band of translucency that was required for optimal aesthetics in this case (Figure 7). Following the simplified layering technique protocol, the dentin-enamel junction (DEJ) was used as a guide for the placement of the dentin layer. Dentin shade A1 was placed to restore the portion that was missing from the fracture. This was placed directly over the lingual enamel layer (Figure 8). The final facial enamel layer was then placed using Pearl Neutral.
|Sorry! It's Part of the Restoration|
Tom M. Limoli, Jr
Finishing and Polishing
Finishing and defining of the facial anatomy were completed using a 48L bur (Brasseler USA). An egg-shaped finishing bur (H379 [Brasseler USA]) was used for lingual anatomy reproduction and for the occlusal adjustments. Polishing was carried out using Jiffy cups (yellow and white) (Ultradent Products), ending with a Jiffy brush (Ultradent Products). Interproximal polishing was done using Epitex (GC America) polishing strips.
The final clinical result (Figures 9 and 10) showcases the remarkable manner in which modern resin chemistry has allowed dentists to duplicate color and light-handling capabilities of natural teeth, while be confident of restorative longevity.
The resin utilized in this case (Vit-l-escence) is a microhybrid resin. It is indicated for use in both anterior and posterior teeth. The authors chose this resin because of the ease in shade matching to the natural tooth, the manner in which the material handles, and the finishing and polishing results that it produces. The shade tabs are fabricated out of the actual Vit-l-escence resin (other systems use dissimilar materials) and are divided into the individual enamel and dentin shades. This unique feature allows the clinician to directly match a resin shade tab to exposed dentin—and the same with the enamel.
Most of the information on shade matching is based on determining an average hue by placing a shade tab on the facial of the tooth to be restored or on the adjacent intact tooth. The problem with this method is that it does not take into account the individual contributions of the dentin and the enamel. On most fractures, the DEJ can be seen, which clearly separates the dentin and enamel components as well as indicates the thickness of each layer. The interplay between the thickness of each layer and how they change from gingival to incisal provides the polychromatic effect visually perceived by the human eye. The authors based their simplified layering technique on this unique anatomical characteristic of the tooth: thinner enamel at the gingival third and thicker enamel at the incisal third.
The case example presented here, involving the successful repair of a tooth with a Class IV fracture, demonstrates how the utilization of a proper protocol and suitable composite resin materials can ensure both beauty and longevity.
- Gutz DP. Fractured permanent incisors in a clinic population. ASDC J Dent Child. 1971;38:94-95.
- Summitt JB, Robbins JW, Schwartz RS. Fundamentals of Operative Dentistry: A Contemporary Approach. 2nd ed. Chicago, IL: Quintessence Publishing; 2001:243.
- Morgan J. Successful management of class IV fractures: Direct bonding and finishing procedures. In: The New Face of Aesthetics; The AACD Monograph. 2004; 1:81–86.
- Vargas M. Conservative aesthetic enhancement of the anterior dentition using a predictable direct resin protocol. Pract Proced Aesthet Dent. 2006;18:501-507.
- Morgan J, Presley S. Conservative treatment of dental trauma in adolescents with malocclusion. J Am Orthodont Soc. 2008;8:34-37.
Disclosure: Dr. Morgan is a consultant for Ultradent Products and other dental companies.
Dr. Presley received his dental degree from Baylor College of Dentistry in 1977. He currently practices orthodontics and cosmetic and restorative dentistry with his wife Dr. Jaimeé Morgan in Salt Lake City, Utah. His training at the L.D. Pankey Institute and Dr. Bob Gerety's straight wire continuum has provided him with a sound cosmetic treatment philosophy. Dr. Presley was one of the founding members of the South Texas Chapter of the American Academy of Cosmetic Dentistry where he served as secretary and vice-president. He is co-developer of the Simplified Layering Technique for composites along with Dr. Morgan. Dr. Presley lectures internationally and has contributed numerous articles demonstrating realistic and learnable procedures for general practitioners. He can be reached at (801) 561-9999 or by visiting the Web site presleyorthodontics.net.
Disclosure: Dr. Presley is a consultant for Ultradent Products and other dental companies.