I 31 industry report _ compobonds I cosmeticdentistry 2_2011 ephemeral, effective for only a few days.28 Future composite developments should endeavour to in- corporate both anti-bacterial and bioactivity in their formulations for enhanced therapeutic value. In conclusion, flowables are useful for areas of reduced occlusal stresses, but are contra-indicated forbulkbuild-upsinstress-bearingareas.Theirpopu- larity is due to ease of use and flexible adaptability, especiallyinareasoflimitedaccess.Theclinicalapplica- tionsincludefissuresealing,smallcavities,baseliners, repairing voids in defective restorations and blocking undercuts for subsequent indirect prostheses. _Evolution of a new resin-based restorative: Compobond As discussed above, the state-of-the-art of den- tine bonding systems are the SE agents that obviate the need to perform an initial etching phase, while yielding bond strengths that are comparable to bonding to enamel. Also, the pinnacle of resin-based composite technology is the introduction of nano and nano-hybrid composites. The advancements in bothbondingagentsandresinshavenowevolvedby uniting these two materials to produce a new dental restorative: compobond. Compobonds exploit the benefits of SE DBAs and nano-filled resins, eliminating the precursory bond- ing stage necessary to adhere a resin to tooth sub- strate, and are termed self-adhering composites. In essence,aneraisemerginginwhichcomposites,sim- ilartoamalgamfillings,canbeplacedinasinglestep, eliminatingerrors,expeditingprotocols,andimprov- ing predictability and longevity of restorations. The first compobond, called Vertise Flow (Kerr), was introduced in 2009, a self-adhering flowable combining a resin-based composite and an SE bonding agent based on the seventh-generation DBA OptiBond All-in-One (Kerr). Vertise Flow is a light-cured composite with similar properties to conventional flowables but with the added ad- vantage of eliminating the bonding stage that is prerequisite before using any resin-based restora- tive (Fig. 5). CharacteristicsandpropertiesofVertiseFlow Vertise Flow incorporates the properties of the DBA OptiBond, the first filled bonding agent intro- duced in 1992 (Fig. 6), that realised the potential of using a filled adhesive as a shock absorber beneath resin-based composite restorations. The bonding mechanism of OptiBond to dentine is two-fold: firstly, chemical adhesion is realised by the phos- phate function group of the GPDM monomer (glycerol phosphate dimetharcrylate) uniting with the calcium ions within the tooth; and, secondly, micromechanical adhesion by formation of the hy- brid layer composed of resin impregnation with the collagen fibres and the dentine smear layer. Initial SEMandTEMimagesfromtheUniversityofLeuven, Belgium, show tight adaptation of Vertise Flow to both dentine and enamel. In addition, micro-leak- agetestsshowthatVertiseFlow’smarginalintegrity is comparable to conventional (i.e. non-adhering) flowablecompositewhenusedincombinationwith an SE bonding agent.29 The shear bond strength (SBS) achievable with Vertise Flow and dentine is approximately 25 MPa, Fig. 23_The post-op view showing sealed fissures and the high lustre obtained after polishing with Opti1Step Polisher (compare with Fig. 11). Fig. 24_Pre-op view showing cavitation in the occlusal surfaces of a maxillary molar and pre-molar. The molar also requires replacement of an occlusal defective composite filling. Fig. 25_Cavity preparation using micro-diamond burs for minimising excessive tooth removal. Fig. 26_All aprismatic enamel margins are carefully bevelled. Figs. 27a & b_The initial layer of Vertise Flow should be < 0.5mm thickness (a) and spread with a brush to ensure intimate contact with the cavity walls and bevelled margins (b). Fig. 24 Fig. 25Fig. 23 Fig. 27a Fig. 27bFig. 26