March 1, 2013
by Janet Roberts, BSc, DMD
For more than 30 years, posterior composite restorations have been an alternative to amalgam restorations. Although universal in nature, posterior composites statistically have had higher failure rates and more clinical challenges than their competition.1 While improvements have been made, dentists have still been faced with placing posterior restorations that are time and technique sensitive, necessitating the development of a procedure that must be quickly and accurately performed. Clinicians have also dealt with various challenges when working with traditional direct composites. Historically, these composites require a multiple layering process which is typically long and complicated. The primary drawbacks of traditional direct composites, polymerization shrinkage and shrinkage stress,2 increase the likelihood of marginal leakage, secondary caries, and postoperative pain.3
In order to reduce or eliminate these disadvantages, numerous manufacturers have invented bulk fill resin composites to simplify and quicken the process of filling direct posterior cavities. Clinicians now are able to confidently place posterior restorations in esthetic and straightforward ways. Bulk fill composites reduce shrinkage stress and ensure a complete depth of cure up to 4mm, eliminating the need for layering and the inclusion of a final “capping layer.”4 Time is saved without compromising marginal integrity and long-term predictability of the restoration. The features of amplified elasticity and low polymerization shrinkage stress reduce microleakage and postoperative sensitivity. The progression of bulk fill composites and new improvements in resin and photopolymerization technology enables dentists to be productive without sacrificing quality.
Tetric EvoCeram® Bulk Fill, however, represents a significant advancement in resin-based filling materials and an entirely new technology for the faster, more efficient placement of direct composite restorations without compromise to any physical properties. Formulated with patented Ivocerin® — a new light-initiator that provides deeper and more efficient depth-of-cure and shorter curing time — Tetric EvoCeram® Bulk Fill is easily adaptable, completely curable, and a low shrinkage material that provides the perfect combination of productivity, performance, and esthetics.
Ivocerin is a new germanium-based light-initiator developed by Ivoclar Vivadent and used exclusively in Tetric EvoCeram® Bulk Fill. This new initiator allows Tetric EvoCeram® Bulk Fill to cure faster and deeper than other composite materials without increasing translucency or reducing working time. The absorption spectrum of Ivocerin fills the “gap” between traditional light-initiators (e.g., Lucerin TPO, PPD, Camphorquinone) used in today’s most popular composite materials. It not only cures fast, but it cures well beyond the 2 mm limit of traditional initiators, achieving an efficient depth-of-cure at 4 mm. Traditionally, conventional direct composites are placed and cured in incremental layers of 2 mm or less.2,3
With Ivocerin, Tetric EvoCeram Bulk Fill can be cured in layers of up to 4 mm in just 10 seconds (using a light with minimum output > 1,000 mW/cm2). Additionally, because Tetric EvoCeram® Bulk Fill contains a shrinkage stress reliever, the shrinkage stress distributed along cavity walls and surfaces, and shrinkage volume experienced during polymerization, are exceptionally low.
Layered silicates in Tetric EvoCeram® Bulk Fill produce a smooth consistency that adapts well to cavity walls and can be applied and contoured easily with conventional dental instruments. No additional expensive equipment — or the use of a flowable composite (in most cases) — is required. Restorations are polished quickly and easily due to the material’s well-balanced filler composition. The three universal shades (IVA for slightly reddish teeth; IVB for slightly yellowish teeth; and IVW for quick deciduous fillings or light-colored teeth) demonstrate an enamel-like translucency of 15%, so restorations blend seamlessly with natural dentition.5 Yet, the material demonstrates high radiopacity for easy detection on dental x-rays.
A 44-year-old male patient presented for a routine oral examination and was found to be in good overall health. Upon examination, a carious lesion was detected on the occlusal-lingual of tooth #26 (i.e., upper left first molar). A treatment plan using a nanohybrid bulk fill composite material (Tetric EvoCeram® Bulk Fill) to restore the carious tooth was presented to and accepted by the patient. This nanohybrid composite was chosen to streamline the restorative procedure and provide an esthetic and predictable result for the patient.
To begin treatment, the area surrounding the carious upper first molar was anesthetized, and a rubber dam was placed to ensure proper and good isolation during preparation (Fig. 1). Upon further examination, it was determined that although the lesion initially appeared fairly small from the occlusal, the caries extended quite deeply into the occlusal pit area. While a preparation of this depth would normally have required several 2-mm increments of composite resin to fill using traditional materials, Tetric EvoCeram® Bulk Fill was chosen to fill the entire cavity and mold to ideal contour with one increment of material.
Next, the cavity outline was completely cleansed using copious amounts of water spray (Fig. 2) and then dried. The preparation was then etched with 37% phosphoric acid (Total Etch) for 30 and 15 seconds on the enamel margins and dentin, respectively. The acid was vigorously rinsed off and then the surfaces lightly air dried, leaving the dentin slightly moist. Caution was taken not to leave the preparation with pooling water, and not to over-dry the dentin (Fig. 3).
Next, using a microtip brush, a 5th generation adhesive (the ExciTE F, Ivoclar Vivadent), was applied to the enamel margins and exposed dentin (Fig. 4). The resin was agitated with the microtip brush for 15 seconds to ensure complete coverage of the margins and walls of the cavity preparation. This was performed in one swift application. Once completed, the excess adhesive was dispersed with a light stream of air for a minimum of 20 seconds to evaporate the solvent and eliminate the possibility of resin pooling. A uniform, glossy appearance showed the tooth was completely sealed. Afterward, the adhesive was light cured for 10 seconds using an LED curing light (Bluephase 20i, Ivoclar Vivadent) on its soft cure mose setting (Fig. 5).
Afterwards, a single increment of bulk fill composite (Tetric EvoCeram® Bulk Fill) was placed into the tooth #26 preparation, up to 4 mm. The most appropriate esthetic shade of composite for this case, IVA (for reddish tinted teeth), was selected. Composite contouring instruments were utilized to craft natural anatomical contours. Then, the composite was light cured using the same LED curing light, this time on Turbo setting, for 5 seconds from occlusal direction (Fig. 6). This light provided 2000 mW/cm2 of curing capability.
Immediately after the composite had been cured, only minor finishing was required to remove excess flash. The rubber dam was removed, and the patient’s occlusion was checked and slightly adjusted. The final step was to polish the restoration using the Astropol polishing system (Fig. 7). Once completed, the restoration was shown to the patient for approval and accepted (Figs. 8 & 9).
The handling characteristics of Tetric EvoCeram® Bulk Fill composite and its working time allowed it to be shaped and sculpted to ideal contours prior to curing. The material’s consistency, which holds its shape, allowed for easy marginal adaptation and groove placement. Overall, Tetric EvoCeram® Bulk Fill composite perfectly combines perfo
rmance, esthetics and productivity, while simplifying the procedural method for direct posterior restorations. This bulk fill composite with patented Ivocerin has replaced a labor intensive procedure vulnerable to failure with a fast, easy to accomplish, and steadfast technique. Required chair time is cut by half, resulting in decreased cost and discomfort for patients, and increased productivity for dentists.OH
Janet Roberts, BSc, DMD, Co-partner of A Smile Above Cosmetic Dental Practice, Vancouver, BC. T: 604.688.4422. E: email@example.com. Oral Health welcomes this original article.
1. Sarrett DC. Clinical challenges and the relevance of materials testing for posterior composite restorations. Dent Mater. 2005 Jan; 21 (1):9-20.
2. Giachetti L, Scaminaci Russo D, Bambi C, Grandini R. A review of polymerization shrinkage stress: current techniques for posterior direct resin restorations. J Contemp Dent Pract. 2006 Sep 1;7 (4):79-88.
3. Cheung GS. Reducing marginal leakage of posterior composite resin restorations: a review of clinical techniques. J Prosthet Dent. 1990 Mar;63(3):286-8.
4. Ferrcane JL. Resin composite-state of the art. Dent Mater. 2011 Jan;27(1):29-38. Epub 2010 Nov 18.
5. Tetric EvoCeram Bulk Fill: The bulk composite without compromises. Scientific Documentation. Schaan, Lichtenstein Ivoclar:Vivadent; 2011: 1-20.