Written by Cathia Bergeron, DMD, MS Sunday, 28 February 2010 19:00
Anterior composite restorations present many aesthetic challenges to the clinician, and the difficulties increase with the size of the restoration. However, the quality of composite materials has advanced steadily in recent years, to the point that it is now more possible than ever to achieve both high aesthetics and high strength with a composite resin restoration. A careful and precise technique is of course vital to the success of any case, but the results that can be achieved with composite continue to grow more impressive.
To understand how the materials have advanced, a review of nanofiller technology is helpful. Nanofilled composites have been the object of much attention from the dental community for their ability to withstand wear better than other types of composite. However, experience shows that the use of nanoparticles in a composite does not automatically guarantee strong performance. The manner in which the nanoparticles are incorporated plays a significant role in how the material performs, both in the office and over time in the patient’s mouth.
RETAINING POLISH FOR LONG-TERM WEAR
Microfill composites, often presented as a better-wearing alternative to hybrid restoratives, do in fact retain polish better, but do not offer the same strength. This is due to the weak link created by the bond between the resin matrix of the microfill and the prepolymerized “organic filler” matrix. Studies have demonstrated that under stress and fatigue, microfill composites often fracture along the lines between these particles.1,2 Evidence demonstrates that microfills are also more prone to marginal breakdown under occlusal loading.3 A nanocomposite, however, does not use a prepolymerized filler. Additionally, because the material’s nanoclusters act as a single unit, they enable a high filler loading. These characteristics result in higher strength than what is found in microfills. The combination of the highfiller loading and the material’s advanced resin matrix allows it to offer high compressive strength, flexural strength, and diametral strength, as well as fracture toughness.
Figure 1. The patient had broken both teeth Nos. 8 and 9 from a fall.
Figure 2. The teeth were prepared with infinite bevels.
Figure 3. A small amount of composite in shade A1E was placed in the lingual matrix.
Figure 4. A football burnisher was used to attach the resin.
Figure 5. The index was removed, leaving a lingual shell on which the remainder of the restoration was built.
Figure 6. A halo was created using white tint at the incisal edge.
Figure 7. Shade A2B was utilized for the dentin buildup.
Figure 8. The final enamel layer was shaped with an interproximal carver, gold Almore instrument and brushes.
Figure 9. Composite was placed first in the lingual matrix, then brought to the teeth and attached with a football burnisher and a brush to create the lingual shelf.
Figure 10. The distal contact and surface were formed.
The patient, a 22-year-old male, visited the clinic after having broken teeth Nos. 8 and 9 in a fall the previous night (Figure 1). The patient’s college graduation was in 3 days, and he was seeking a way to repair the teeth quickly and aesthetically. Radiographs were taken, and because of the severity of the break on tooth No. 9, it was also tested for vitality with an electric pulp test, a cold test, and a percussion test prior to determination of treatment. All test results showed the tooth to be vital, and the patient agreed to proceed with a resin buildup. The patient was informed at this time that tooth No. 9 would have to be monitored closely with regular 6-month checkups to ensure its ongoing vitality, and he understood that a root canal might eventually become necessary.
Figure 11. The mesial contact, surface and embrasure were created.
Figure 12. The final proximal surfaces.
Figure 13. Final contour of the restorations before finishing.
Figure 14. The completed restorations.
Figure 15. A very natural emergence profile was achieved.
Following completion of tooth No. 8, tooth No. 9 was treated similarly. Celluloid strips (Epitex clear matrix [GC America]) were placed to protect the adjacent teeth during etching and bonding, then removed following curing of the bonding agent. Composite resin was again placed first in the lingual matrix (Figure 9), then brought to the teeth and attached with a football burnisher (Tarno hac No. 6 [S.S. White]) and a brush to create the lingual shelf. A metal matrix (Original Tofflemire matrix band No. 1, .0015 in [Water Pik]) was placed and the distal contact and surface were built with A1E material (Figure 10). The same process was then used to create the mesial contact, surface and embrasure (Figure 11).
Composite resin is an appealing restorative option, especially for young patients. While conservative, the material can still provide a very good aesthetic outcome. The additional time demand demonstrated in this case also illustrates an important benefit of composite—it can be used to quickly create large restorations that help patients feel confident in their appearance. Rather than being fitted with a temporary crown for his graduation, this patient was able to attend his event with a lifelike final restoration in place.
- Lambrechts P, Vanherle G. Structural evidences of the microfilled composites. J Biomed Mater Res. 1983;17:249-260.
- Drummond JL. Cyclic fatigue of composite restorative materials. J Oral Rehabil. 1989;16:509-520.
- Ferracane JL, Condon JR. In vitro evaluation of the marginal degradation of dental composites under simulated occlusal loading. Dent Mater. 1999;15:262-267.
Dr. Bergeron graduated from Laval University (Québec, Canada) in 1993, where she also completed an Advanced Education in General Dentistry program the following year. She received a Certificate in Operative Dentistry and a Master of Science degree from the University of Iowa in 1999, after which she taught as an associate professor at the Faculty of Dentistry of Laval University from 1999 to 2007. She joined the department of Operative Dentistry at the University of Iowa in 2007 as clinical associate professor where she currently teaches undergraduate and graduate students. Dr. Bergeron maintains an intra-university practice limited to operative dentistry with a strong emphasis on aesthetic dentistry. Her primary interests are in the areas of aesthetics, composite resins, dental adhesion and minimally invasive dentistry. She is involved in giving continuing dental education courses, lectures and hands-on programs, to professional organizations and study clubs internationally. She can be reached via e-mail at firstname.lastname@example.org.
Disclosure: Dr. Bergeron has disclosed that the composite and adhesive materials for this case were made available for use at no charge by 3M ESPE. Their support is hereby acknowledged and appreciated.
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