KERR Corporation
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To most doctors, the potential benefits of bulk fill composites are obvious. They offer faster and easier placement, simplifying one of the most time consuming and tedious tasks in dentistry. However, some clinicians are rightly concerned that they may be making a compromise in quality with a bulk fill product, which is an unacceptable tradeoff.
Certainly, there are specific features any bulk fill product must offer to alleviate these concerns. First, a bulk fill product must achieve intimate adaptation with the often complex internal cavity surface. Failure to achieve this adaptation could result in gaps between the tooth/adhesive layer and the resin composite, which in turn present potential clinical problems or failures.
Adequate curing is essential to maximize the mechanical properties of the composite and reduce the patient exposure to uncured methacrylate monomers that can act as an irritant to oral tissue. Most materials can be reliably cured to 2 mm with a high-powered curing light, so a bulk fill product must cure beyond this depth.
All composites shrink, and the force created by this volume loss (shrinkage stress) can cause debonding, cuspal flexure (cusps are pulled inward), or even both. Debonding may eventually lead to recurrent decay, and cuspal flexure could cause microfractures in the tooth and/or postoperative sensitivity. So bulk fill resins must offer an equal, or even decreased level of shrinkage stress compared to a conventional material placed in layers.
Beyond these three requirements, a bulk fill resin should still satisfy all the performance requirements that clinicians have come to expect of restorative composites. This includes adequate mechanical properties and esthetics acceptable for the application. Taken together, adaptation, depth of cure, shrinkage stress, mechanics, and esthetics provide a good framework for considering a bulk fill product.
SonicFill™ 2 from Kerr has been designed to meet all of the requirements listed above with a single application of a single material. The system consists of a handpiece that applies sonic energy while dispensing a unique composite with modifiers that react to the sonic energy, greatly improving adaptation and reducing shrinkage stress. SonicFill 2 can be placed in increments of up to 5 mm and offers the following features:
• Excellent adaptation
• Low shrinkage stress
• High depth-of-cure
• Excellent mechanical properties including strength and wear resistance
• Outstanding color-match and polishability
SonicFill 2 is the most popular bulk fill product in the United States, with well over 20 million restorations placed worldwide since SonicFill was introduced several years ago.
As for light-curing, there are many excellent curing lights available on the market, but there are special features in the Kerr Demi™ Ultra that enable it to maximize power while keeping the tooth cooler than lights. Demi Ultra offers CURE Technology that provides beams of light that are more like columns, thus delivering more light and curing energy to the restoration. Heat is also minimized through efficiency by placing the LEDs at the curing tip, so the light travels a shorter distance. Minimizing heat on gingival tissues is clinically important to reduce incidence of extended postoperative sensitivity and to avoid potential irreversible pulpitis. Also, the Demi Ultra is able to store energy using an ultracapacitor rather than a battery. Recharging would take up to 2 hours with a battery, but the Demi Ultra re-energizes in only 40 seconds and is sufficient for about 25 10-second cures with an ultracapacitor.
Both SonicFill and the Demi Ultra curing light can be easily mastered using provided instructions and materials. Kerr is committed to education that goes far beyond mastery of its products. Kerr Professional Education, which was launched this year, focuses on education to doctors in multiple settings. There are hundreds of courses for which doctors can sign up and get CE credits.