Composite Layering Class IV Fracture Repair Using Nature as a Guide
Introduction
Maxillary central incisors are the most commonly fractured teeth in the mouth, mainly caused by dental trauma during childhood. Depending on the extent of the fracture, a composite restoration can be a predictable, affordable, and fast option to treat these emergencies.
Maxillary central incisors have the most variable incisal characterizations, which can be challenging to blend seamlessly into a composite restoration. It usually takes more than one appointment to achieve an esthetic result. Understanding the optical properties of composite and layering techniques is essential for seamlessly restoring a fractured central incisor as conservatively as possible. This article discusses utilization of a practical layering technique to provide a predictable and quick solution for the patient.
“Understanding the optical FIG. 3 properties of composite and layering techniques is essential for seamlessly restoring a fractured central incisoras conservatively as possible.”
The patient presented to the office due to a previously restored restoration that had fallen off (Figs 1 & 2). Since the fractured part of tooth #21 was small and the occlusal relationship of the patient was fine, the best restorative option proposed to the patient was a new composite filling.
Treatment Planning
Incisal characterizations, dental anatomy, and treatment planning are fundamental to achieving lifelike restorations. Both maxillary central incisors should be “mirror images” of each other; this is critical to achieve an esthetic and natural result.
The first step to attaining matching central incisors is to analyze the incisal characterizations and dental anatomy of the contralateral tooth. The incisal characterization showed 1 to 1.5 mm of incisal translucency and a light halo at the incisal edge. There were also some hypocalcifications in the middle of the tooth, increasing in quantity at the incisal edge (Fig 3). When comparing the dental anatomy of the intact tooth #11 to the fractured tooth #21, the distal line angle of tooth #11 had an "S" curve starting at the end of the gingival third of the central (Fig 4) and low to no surface texture.
FIG. 3 Incisal characterizations of tooth #11.
FIG. 4 Dental anatomy from a right lateral retracted view.
“Both maxillary central incisors should be 'mirror images' of each other; this is critical to achieve an esthetic and natural result."
Surface Preparation & Shade Match
A shade match was taken at the beginning of the appointment before any dehydration could affect the shade selection1. Two proposed shades of the composite material were placed onto the incisal edge and light cured to verify the proper shade.
There is no need to aggressively grind the tooth to a stump when a conservative solution can be applied in a single appointment. It is important to let the patient know at the beginning of the appointment that the shade match may not be correct by the end of the appointment, but will be correct several hours later when the tooth is fully rehydrated.
No local anesthesia was given to the patient. Any residual composite left on the tooth was removed to achieve a better bond to the enamel surface. The tooth was then beveled at the junction of the fracture with two planes. The first plane consisted of a deep bevel that was approximately 1.5 mm in depth and a small bevel at the cavosurface margin to make this line disappear. The second was a shallower and longer bevel, with multiple bevels that varied in quantity and depth, utilizing the starburst bevel technique2 with a feather-edge diamond preparation bur 8862.FG.010 bur (Komet USA), in order to blend with the composite on the buccal surface of the tooth (Fig 5). This is called an infinite margin, which means that it does not appear to have an end.3
FIG. 5 Cross-section showing long and deep bevels.
Composite Application
A cutback technique was used for this patient.4 Acid etching with Ultra-Etch 35% phosphoric acid (Ultradent Products) was performed for the entire facial surface of the restoration, as well as slightly beyond the lingual margin. Acid etching is an indispensable step, as unetched facial enamel will lead to bond failure and staining. The facial surface was then checked for composite tags that could be seen as non-frosty enamel. These tags were removed and re-etched. OptiBond FL (Kerr), a gold standard bonding agent5 was applied to the entire facial surface and fracture area. Tooth #21 was then light cured. A body-shade composite A1 Renamel Microhybrid (Cosmedent) was applied to the facial aspect to establish the general primary anatomical shape of the final restoration as reference. A cutback was performed inside the facial, leaving a thin wall of the proximal line angles and the incisal edge intact to create room for layering. This cutback increased in depth toward the incisal edge, where more characterizations were needed. Sandblasting of the composite with 27-um aluminum oxide was performed, and the bonding protocol was performed again.
Colour Map Side View
FIG. 6 Colour map showing a side view of the composite layers.
"This is called an infinite margin, which means that it does not appear to have an end."
Colour Map Frontal View
FIG. 7 Colour map showing a frontal view of the composite layers.
The light halo at the incisal edge was created with an AI-B1-LO Creative Color Opaquer (Cosmedent). A Creative Color Grey Tint (Cosmedent) was applied inside the cutback slightly under the incisal edge to create the incisal translucency. Hypocalcifications were created with a light-cured dental composite White Creative Color Opaquer (Cosmedent) using tooth #11 as a guide (Figs 6-8).
FIG. 8 Frontal 1:1 view demonstrating the tints and opaquers used to replicate the characterizations of tooth #11
A translucent composite shade OA1 Estelite Sigma Quick (Tokuyama Dental) was used to mitigate the effects of the tint and opaquers. The final layer was a clear composite to cover the hypocalcifications and incisal translucency Occlusal Clear Renamel Microhybrid (Cosmedent). The entire composite restoration was then light cured, on top of curing after each composite application.
Finishing and Polishing
The first step in finishing and polishing is establishing the correct incisal edge. A FlexiDisc Mini (Cosmedent)6 large sandpaper disc, which leaves a clean, sharp line angle, was used. The lingual surface of the composite was contoured with a football carbide and checked with articulating paper. To create the proper facial anatomy for identical central incisors, it is helpful to draw pencil lines on the proximal line angles of the contralateral tooth. Adjustments were made with a feather-edge diamond preparation bur 8862 (Komet USA), followed by polishing with coarse sandpaper discs with notches cut into them, which is less aggressive and does not create a rounded shape instead of a flat surface like normal incisors (Fig 9). The sandpaper discs can create a smooth facial surface and remove irregular composite areas. The occlusal view from a mirror can help judge the proper line angles and facial anatomy. Once the proper anatomy was achieved and the teeth were mirror images of each other anatomically (Fig 10), polishing was performed with All Surface Access Polishers (Clinician’s Choice) Pre-polisher and Final High Shine Polisher, and Enamelize & FlexiBuff Mini (Cosmedent).
FIG. 9 Sandpaper disc used to contour the restoration on tooth #21.
FIG. 10 The light reflection shows an "S" curve that is symmetrical to tooth #11.
Summary
The patient was pleased to have her front tooth and smile re-turned to the prefractured condition (Figs 11 & 12). She was satisfied with the conservative yet imperceptible and esthetic solution, where the tooth treated was undetectable.
A Class IV fracture should be considered everyday dentistry. There is no need to aggressively grind the tooth to a stump when a conservative solution can be applied in a single appointment The white spots and incisal translucency made this case more complex.
FIG. 9 Sandpaper disc used to contour the restoration on tooth #21.
FIG. 10 The light reflection shows an "S" curve that is symmetrical to tooth #11.
"Cosmetic dentists should consider themselves artists, and a case like this should be taken on as a challenge. What excellent service for the patient!"
Acknowledgment The author would like to thank Dr. James H. Peyton for the colour map illustrations and help with this article.
REFERENCES
1. Suliman S, Sulaiman TA, Olafsson VG, Delgado AJ, Donovan TE, Heymann HO. Effect of time on toothdehydration and rehydration. J Esthet Restor Dent. 2019 Mar:31(2)-118-23. doi: 10.1111/jerd.12461, PMID: 30801926. 2. LeSage BP. Artstically emulating nature with direct composite restorations. Cosmet Dent. 2021 Fall:37(3):26-38. 3. Hedgecoe D. Conservative and esthetic restoration of a Class IV fracture. Cosmet Dent. 2018 Spring:34(1):16-22 4. Hanson MW. The pursuit of excellence in esthetic dentistry. Cosmet Dent. 2015 Winter:30(4):102-12 5. Van Meerbeek B, Yoshihara K, Van Landuyt K, Yoshida Y, Peumans M. From Buonocore's pioneering acid-etch technique to self-adhering restoratives. A status perspective of rapidiy advancing dental adhesive technology: J Adhes Dent. 2020;22(1):7-34. doi: 10.320/jad.a43994. PMID: 32030373 6. Peyton J. Finishing and polishing a composite restoration (case types IV & V).J Cosmet Dent. Summer 2019;35(2):26-9. jCD
About the Author
Bilal El-Masri, DMD
Dr. El-Masriearned his Doctor of Dental Medicine degree from Laval University in 2021. During his university years, he distinguished himself through his commitment to scientific research, participating in four research projects. This involvement led to his selection as a teaching assistant, where he contributed to the creation of a clinical guide designed to support dental students. Passionate about cosmetic dentistry and gum surgery, Dr. El-Masri has particularly distinguished himself in these fields during his clinical career. His skills and excellence in these specialties have earned him two prestigious scholarships, recognizing his academic and clinical achievements. Eager to share his expertise, Dr. El-Masri regularly offers continuing education courses to his peers to contribute to the advancement of the dental profession.
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This article was published in the Clinical Life™ magazine:
Spring/Summer 2026
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