Case Presentation: Using a Flowable Bulk Fill in Place of Silver Amalgam

Author
10/31/2018
Clinicians have long desired a resin-based composite that would perform successfully as an amalgam replacement. The ease and efficiency of placing silver amalgam restorations is why they’re still used by many practitioners and apparently preferred by a number of dental insurance carriers and government healthcare agencies. Patients, however, strongly favor the esthetics of the resin-based composites, and some have concerns about silver amalgam (mercury) toxicity.1 The dental profession’s concerns are that resin-based composite restorations may not last as long as silver amalgam, and that they are technique sensitive.2 Resin-based composites require more complete isolation, especially during the process of incremental fi lling and adhesive bonding, thereby making amalgams less demanding.

Dental researchers have significantly improved the materials now available to the profession for transitioning away from amalgam in the near future. However, a number of dental professionals and insurance carriers seem blithely unaware of the Minamata Convention on Mercury (see footnote) and the planned phaseout of amalgam materials.3 Removing the need for incremental filling is essential for the efficacy and success of the posterior composite restoration. Although the need for long-term successful adhesion protocols is equally important, this article discusses the clinical application of a flowable bulk fill resin-based composite, Estelite Bulk Fill Flow (Tokuyama Dental).
 
GO-TO PRODUCT USED IN THIS CASE
ESTELITE BULK FILL FLOW
Estelite Bulk Fill Flow is designed to be strong, reliable, and adaptive. It has high compressive and flexural strength, and minimal shrinkage stress. The material easily adapts to the cavity, flowing into the nooks and crannies, providing an excellent marginal seal, and preventing restoration failure.
Case Report
The 8-year-old female patient presents in good health with deep occlusal caries of the second primary molars. She practices a reasonable level of oral hygiene, but is predisposed to occlusal caries due to molar anatomy. Unfortunately, her parents had declined pit and fissure sealants due to the insurance carrier’s lack of benefit for the primary dentition, and now she presents with deep carious lesions. After single tooth anesthesia (Wand STA, Milestone Scientifi c), the molar was isolated with a rubber dam and prepared for an occlusal restoration with high-speed handpiece and #330 carbide bur with adequate water spray (Figure 1). During caries removal with a #4 round bur in a slowspeed handpiece and then spoon excavator, the dentin was kept moist to reduce postoperative sensitivity. Following removal of the infected dentin, the enamel margin was etched for 30 seconds and the dentin for 3 seconds (Figure 2). Then, a resin-based calcium silicate base was placed in the deepest portions of the preparation and light-cured (Figure 3).
Figure 1—Isolation with rubber dam after anesthesia. Very deep anatomy of the primary dentition, predisposed to deep occlusal caries.
Figure 2—After caries excavation, selective etch of the enamel for 30 seconds followed by 3 seconds or less of dentin conditioning.
Figure 3—Placement of the resin-based dicalcium, tricalcium silicate liner in the deepest portion of the cavity prep followed by photopolymerization.
A 7th-generation bonding adhesive, Bond Force (Tokuyama Dental), was placed and polymerized (Figure 4). The preparation was then filled with one increment of the flowable bulk fill resin composite, EsteliteBulk Fill Flow, shade A1, teased into preparation with explorer tine, and light-cured (Figure 5). The innovative composite flows into the cavity preparation, reducing void formation—a problem with many bulk fills. Its translucency allows for complete photopolymerization, but then becomes opaque. This is the result of matching the refractive index of the uncured resin component to the filler component, which then transitions to nonmatching following polymerization, blending with the tooth structure for ultimate esthetics (Figure 6). Anatomy can be achieved with the RAPTOR diamond bur (Kerr Rotary) prior to rubber dam removal (Figure 7).
 
Figure 4—A 7th-generation adhesive is applied to the etched enamel and the conditioned dentin. The adhesive does not require etch conditioning of the dentin.
Figure 5—After fl owing the Estelite Bulk Fill Flow into the cavity prep, an explorer tine may be used to tease the resin-based composite onto the margins.
Figure 6—After light polymerization, the translucent Estelite Bulk Fill Flow becomes opaque.
After removal of the rubber dam, the occlusion was checked and adjusted with articulation paper and carbide burs. The patient has been followed at recare visits and the restorations checked for wear, discoloration, marginal integrity, and other parameters (Figures 8A-B).
Figure 7—A Raptor diamond bur re-creates the appropriate anatomy with the rubber dam still in place.
Figures 8A-B—Images of the restoration at a recare visit demonstrate lack of wear, marginal integrity, and maintenance of the esthetics.
The introduction of the new flowable bulk fill resin-based composites is an important step in the transition away from the use of silver amalgam in accordance with the Minamata Convention. The ease of use and efficacy of restoration placement with Estelite Bulk Fill Flow is very worthy of consideration for all dental clinicians.

Footnote
The Minamata Convention on Mercury is an international treaty, effective as of August 2017, designed to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds.
 
MARK L. CANNON, DDS
Dr. Cannon received his Doctorate of Dental Surgery from the University of Nebraska and his Master of Pediatric Dentistry from Northwestern University. After completing a residency at Children’s Memorial Hospital, he received his Diplomate status from the Board of Pediatric Dentistry. He maintains a large private practice focused on pediatric and orthodontic care in the suburbs of Chicago.
  1. References:
  2. Direct composite resin fi llings versus amalgam fillings for permanent or adult posterior teeth. M. Graciela Rasines Alcaraz, Analia Veitz-Keenan, Philipp Sahrmann, Patrick Roger Schmidlin, Dell Davis, Zipporah Iheozor-Ejio for Cochrane Database Syst Rev. 2014; (3): CD005620. Published online 2014 Mar 31. doi: 10.1002/14651858.CD005620.pub2.
  3. Amalgam or composite fi llings--which material lasts longer? Hurst D. Evid Based Dent. 2014 Jun;15(2):50–1. doi: 10.1038/sj.ebd.6401026.
  4. Phase down of amalgam: Awareness of Minamata convention among Jordanian dentists. Mohammad A. AL-Rabab’ah, Mohammad A. Bustani, Ameen S. Khraisat, Faleh A. Sawair. Saudi Med J. 2016 Dec; 37(12): 1381–1386. doi: 10.15537/smj.2016.12.16163.