Bulk-Fill Composites in Pediatric Restorations
The advantages of this material class make it ideal for young patients
Joshua Wren, DMD
Private Practice
Brandon, Mississippi
Dentists specializing in pediatrics share many challenges with dentists in general practice, but with some added twists. For example, esthetics are important for children, just as they are for adults, but parents may opt to make esthetic compromises if a primary tooth is not expected to remain in the mouth much longer. Being comfortable in the dental office is also important for young patients, just like adults, but a child is often much more honest about the degree of his or her discomfort. Finally, the efficiency of the dental procedure is important to both children and adults, but pediatric dentists know just how quickly a treatment can turn from routine to bad when the minutes drag on.
For these reasons, pediatric dentists place a high priority on products and treatments that are efficient and predictable. The ideal treatment proceeds as quickly as possible while providing results that will last as long as necessary to prevent retreatment. This is important not only in the name of providing quality care, but also in establishing trust with young patients and helping them learn to be comfortable in the dental chair.
Tackling Caries with Composite Resins
Caries is one of the most prominent issues faced by the pediatric dentist. Data from the National Health and Nutrition Examination Survey showed that 42% of children aged 2 to 11 years have had dental caries in their primary teeth. The survey also estimated that 23% of children aged 2 to 11 years have untreated dental caries.1
These figures highlight the need for pediatric dentists, and dentists in general, to provide ready access to caries treatment, and to perform treatment that is effective and economical, as well as suitable for the unique behavioral and emotional factors associated with pediatric patients.
When treating caries, pediatric dentists typically choose from a small pool of options. Stainless steel crowns and amalgam remain viable options,2 but in many families, esthetics is a priority even for primary teeth. In many parts of the world, composite restorative materials have now nearly completely replaced amalgam treatments for teeth in the posterior.3
When choosing composite resin materials, it is important to understand their various classifications and how they have evolved to their current state. The early generations of composite resin products are categorized as “macrofills” according to their particle size. The relatively large particles in these products provided good strength but made restorations that were difficult to polish.4 Microfills, the next generation, delivered much better polishability but were not known for strength.5
Hybrids, microhybrids, and nanohybrids then followed—materials that were designed with high filler loading to provide strength.4 However, as these materials age, they can suffer esthetically as a result of the wearing away of resin particles from the surface.6 This problem is addressed by a nanocomposite material, which is made with lab-engineered particles, as opposed to the milled and ground particles of hybrids, microhybrids, and nanohybrids.4 The particles in this material form nanoclusters that combine the strength of larger particles and the long-lasting esthetics of smaller particles.6
Dispelling Bulk-Filling Myths
In addition to understanding of the various types of composite resin materials and their strengths and weaknesses, the dentist can also consider which placement technique to use in different clinical situations. The case described in this article involved a posterior preparation approximately 5 mm deep, making it a model candidate for the bulk-filling technique. While the standard of care for preparations greater than 2 mm deep has long been placement of composite in layers,4,7-9 this is time-consuming and not optimal for a pediatric case.
The bulk-filling technique was somewhat controversial for a period of time, due to several factors. One main concern initially stemmed from the packable composites that were first used with the technique in the 1990s. Packable materials, with a high viscosity and high filler load, did not always adapt well to the preparation surface.10,11 Furthermore, it was discovered that the 4 to 5 mm depth of cure that was supposedly possible with these materials was not consistently being achieved.12 Finally, there have been concerns related to polymerization shrinkage stress.13
Fortunately for pediatric dentists and anyone who regularly restores teeth with 4 to 5 mm preparations, bulk-fill composite materials have now advanced to a point where they are regularly used with confidence. Numerous studies have demonstrated adequate results for polymerization properties and marginal quality, and the latest materials are also formulated to create lower polymerization shrinkage stress than the layering technique while still maintaining an acceptable post-cure depth.14-16 With these advances, bulk-fill composites can now be a reliable and predictable tool for treating posterior caries lesions very efficiently and have also become much more esthetically pleasing.
Case Presentation
An 8-year-old female patient presented after an existing restoration placed by another practitioner had debonded. The previous restoration, on the mandibular left primary second molar (tooth K), was likely a glass ionomer; the caries lesion in the tooth had previously been excavated (Figure 1). In addition to the lost restoration, the maxillary right primary first molar (tooth B) was necrotic.
A stainless steel crown was an option to replace the missing restoration, but given that the area had already been treated with a direct restoration, treatment with a composite was chosen for efficiency and esthetics. Consent was also given for the extraction of tooth B.
The area was anesthetized and refinements were made to the old tooth preparation to ensure full caries lesion excavation and beveled margins. The final preparation was a depth that would have required multiple layers of traditional, non-bulk fill composite and was very broad buccal-lingually, almost approaching a cusp replacement. A distal-occlusal preparation was considered but it was determined that occlusal would be adequate for this particular case, especially because it was on a primary tooth.
A bulk-fill composite was chosen for this case, as opposed to a sandwich technique with a glass ionomer to replace the dentin followed by composite. When treating a child with several dental needs, a speedy procedure completed with a single high-quality material is a very important advantage. Glass ionomers can offer the benefit of fluoride release, but for this author, the most important factors for the long-term success of a restoration include proper isolation, attention to detail, and effective home care. The fluoride release of the glass ionomer in this case was not deemed beneficial enough to warrant a longer procedure.
An Isolite mouthpiece (Isolite Systems, www.isolitesystems.com) was placed for isolation and the preparation was thoroughly cleaned. A selective etch was performed on the enamel, followed by use of Scotchbond™ Universal Adhesive (3M ESPE, www.3mespe.com). The adhesive was scrubbed into the preparation for 20 seconds, briefly air-dried, and then light-cured for 10 seconds.
Filtek™ Bulk Fill Posterior Restorative (3M ESPE) was then dispensed into the restoration, beginning at the deepest portion and with the capsule tip withdrawn slowly as the cavity was filled. To help prevent voids, it is important to not lift the tip out of the dispensed material while dispensing. Once dispensing was complete, the capsule tip was dragged against the cavity wall while it was withdrawn from the field.
Shaping was then performed with composite instruments, and the area was cured with the Elipar™ S10 Curing Light (3M ESPE) for 20 seconds on the occlusal surface. With the chosen composite material, full-depth light curing can be achieved at a depth of up to 5 mm a Class II restoration or 4 mm for a Class I restoration by using a high-intensity curing light, such as the one mentioned here.
Occlusion was then checked and a brief finishing and polishing procedure was performed. Because the restoration was placed on a primary posterior tooth, a limited amount of time was devoted to finishing and polishing, but the material finishes very nicely even with minimal time spent on this step. The total time spent performing the restoration procedure was less than 5 minutes.
Following the restoration, the necrotic tooth was then extracted in the same appointment. The patient did remarkably well with both procedures.
Discussion
The very quick treatment time achieved in this procedure is typical for a bulk-fill case and exemplifies the advantages of the material, particularly for pediatric treatments. While the patient in this case tolerated the treatment well, many dentists know the challenges and behavioral unpredictability of pediatric patients, so saving time is always a priority.
Conclusion
The pediatric dentist has an important duty with young patients—to prepare them and lay the foundation for a lifetime of good oral health and trust with the dental team. By treating caries quickly with reliable tools, the dentist can help teach the patient that the dental chair is nothing to fear, and that they can leave the office with a healthier smile than when they arrived.
Disclosure
Joshua Wren, DMD, received an honorarium from 3M.
References
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