With the introduction of a flowable bulk-fill composite to complement its sculptable posterior composite Tetric EvoCeram Bulk Fill, Ivoclar Vivadent has taken bulk filling to the next esthetic level.
Today, composite resins are routinely used as posterior restoratives in dental clinics [1, 2]. That is why dentists have been eagerly awaiting improvements related to these materials and the associated techniques which will allow them to offer their patients more efficient treatment modalities. In response to these expectations, conventional composites have been further developed. Materials known as bulk-fill composites have lately entered the market. These restoratives are placed using a simple protocol to produce very attractive results in posterior teeth .
The marginal adaptation of bulk-fill restoratives is similar to that of layered composites . In addition, these materials show similar/lower shrinkage compared with conventional composite resins and they offer a high depth of cure in increments of up to 4 mm . Nevertheless, in order to obtain successful results, it is important to observe the light-curing instructions of the manufacturer .
The flowable bulk-fill composites are generally used as a base layer in Class I and II restorations [7-9]. They are subsequently covered with a layer of conventional or bulk-fill composite.
The next level
Tetric EvoCeram® Bulk Fill, which was introduced in 2011, is a sculptable posterior composite that can be placed in layers of up to 4 mm. Its chemical composition is based on that of the time-tested Tetric EvoCeram universal composite, which has an excellent 10-year clinical track record . The patented light initiator Ivocerin® contained in these products sets these materials apart from other bulk-fill composites [11-13]. Due to Ivocerin, composite layers of up to 4 mm can be reliably cured.
The new Tetric EvoFlow® Bulk Fill takes the esthetics of bulkfill composites to the next level. This flowable posterior composite can be used as a base layer in Class I and Class II restor ations and as a filling material in deciduous teeth.
As a result of the patented light initiator Ivocerin in combination with the Aessencio® technology developed by Ivoclar Vivadent, up to four-millimetre increments of this composite can be reliably light cured. During the polymerization process, the translucency of the restorative drops from 28 % to < 10 %. Consequently, even stained dentin tooth structure can be successfully concealed. Furthermore, this new material has convenient self-levelling properties, and it optimally adapts to cavity walls . Both types of composites show reduced shrinkage stress, since they contain an elastic resinous filler, also known as a “shrinkage stress reliever”, in addition to the standard fillers. Consequently, the features of these composites are similar to those of conventional layered composites . The highly reactive light initiator and the light sensitivity filter, both of which have been patented, impart these two restoratives with a longer working time compared with other composites  under the usual light conditions of the dental office. Nevertheless, they require only short polymerization .
Clinical case: IPS Empress Direct vs Tetric EvoCeram Bulk Fill as a capping layer
The patient presented with Class II restorations in tooth 36 and 37 showing leakage on the mesial and distal sides (Fig. 1). The treatment plan entailed restoring tooth 36 with an initial layer of Tetric EvoFlow Bulk Fill and a covering layer of Tetric Evo Ceram Bulk Fill. The highly esthetic composite IPS Empress® Direct was chosen as a covering layer for tooth 37 in order to assess the esthetic and process-related differences.
Restoration of tooth 37
The old restoration was removed from tooth 37 and the lesion was cleaned. A cavity depth of more than 5 mm was established in the process (Fig. 2). Next, the dental enamel was etched with phosphoric acid (Total Etch) for 30 seconds (Fig. 3). The Adhese® Universal bonding agent was applied with the brush tip of the VivaPen®, the delivery form for efficient application (Fig. 4). Subsequently, the bonding agent was distributed with blown air and then poly merized with Bluephase® Style for 10 seconds. Then, a layer of Tetric EvoFlow Bulk Fill was applied on the mesial and distal sides of the cavity and polymerized for 10 seconds with Bluephase Style (Fig. 5). As a result of the Aessencio technology, the translucency of the material changed during the polymerization process. This improved the integration of the restoration and maximized the esthetic effect from within the restoration (Fig. 6).
Next, the restoration was built up in layers using IPS Empress Direct. OptraSculpt® instruments were used to shape the composite (Figs 7 and 8). The restoration was polished to a highgloss finish with Astrobrush® silicon carbide brushes (Fig. 9).
Restoration of tooth 36
The old composite restoration in tooth 36 was removed. The resulting cavity was also more than 5 mm deep (Fig. 10). The tooth was pretreated in the same way as tooth 37 (Figs 11 and 12). Subsequently, the flowable Tetric EvoFlow Bulk Fill was applied to the mesial and distal sides of the cavity (Fig. 13). The restoration was cured with Bluephase Style for 10 seconds. The sculptable Tetric EvoCeram Bulk Fill was applied as the last volume replacement layer. OptraSculpt instruments were used to shape the desired occlusal anatomy (Figs 14 to 16). The restorations showed comparable results when they were polished to a high-gloss finish with Astrobrush (Fig. 17). Topical fluoride (Fluor Protector S) was applied as a preventive measure as soon as the restorations were completed (Fig. 18).
The restorative materials Tetric EvoFlow Bulk Fill and Tetric EvoCeram Bulk Fill can be reliably used in the posterior region. The esthetic properties of these bulk-fill restoratives are comparable to those of conventional composites. Their clinical application protocol is easy, practice-oriented and efficient.