cosmetic dentistry_ beauty & science

aesthetic white restorations is far greater than the single-step amalgamfillings. The launch of bulk-fill com- posites, or deep resins, a few years ago is a sign of the times. The epicurean and prosperous lifestylesofthelasttwodecades are being traded for austerity and frugal constraints. Hence, the introduction of these resto- rative materials is both timely andfortuitous. Both patients and dentists are forgoing their hedo- nisticdemeanourforasceticism,seekingwaystoreduce expenditure while striving to maintain standards. Pa- tientsaredecliningtreatmentplansthattheymayhave considered prior to the credit crunch, in favour of sim- pler and cost effective methods for restoring dental health. In addition, dentists are no longer complacent aboutelaboratetreatmentplanacceptance,andinstead are offering less expensive, timesaving alternatives for achieving health and function, without the opulence of superlative aesthetics. Thus, the bulk-fill deep resins, which offer expediency and reduced treatment cost, arecateringforthecurrenteconomicvolatilemarket. _Incremental vs. bulk-fill Currently, the options for placing direct tooth co- louredrestorationsareeitherbytheincrementalorbulk- fill approach. The rationale for incremental layering is thatmostuniversalhybridcompositescanonlybecured to a depth of 2 mm, and hence consecutive layers are necessarytofillthecavity.1 Furthermore,successivelay- ersreducethecavityconfigurationfactor(C-factor)for loweringpulpaldeflection2 andmitigatingbondfailure3 following polymerisation shrinkage. In addition, supe- rioraestheticscanbeachievedbymimickingthenatural dentine and enamel layers with corresponding incre- ments of the RBC and incorporating specific tints and stains. Hence, highly aesthetic restorations with supe- rior anatomical form are possible. However, with con- temporaryuniversalhybridcompositespossessinglow- shrinkage&low-stress,4 theC-factorandmicroleakage arelessofaconcern.5 Thedisadvantagesofincremental layering is the onerous process with greater probability for introducing porosity between the layers, and the protractedtreatmentsessionisreflectedbyahighercost for the patient. Furthermore, the initial flowable stress relievingliningisineffectiveforreducingcuspaldeflec- tion,6 furtherquestioningthevalidityofthisprocedure. Unquestionably,theincrementalapproachisideally suited for anterior restorations where aesthetics are a prime concern, but is it also necessary for posterior restorations? In a recent article, Smales et al.7 stated that “…clinical technique is the determining factor for successandlongevityofcomposites”,andaddedthere has been “…little improvement in the last 30 years!” Therefore, any procedure that simplifies the taxing clinical technique of composite placement is likely to improve predictability and durability of restorations. Consequently, introduction of bulk-fill resins endeav- ourtoexpeditedirectcompositerestorationsinposte- riorteeth.Therationalofthebulk-fillresinsisreducing clinical steps by a filling the cavity in a “single” incre- ment, thereby simplifying the existing incremental technique. This also ensures reduced porosity and uni- form consistency restoration, with reduce clinical time andcostforthepatient. Atpresentthreetypesofbulk-fillresinsareavailable, distinguished primarily by their viscosity, which is low, medium or fluctuating. The low viscosity variety offers superior adaptability, while the medium viscosity type is better for carving and sculptability (see schematic representationontheillustrationbelow). _A utopian composite? Contemporary resin-based composite filling mate- rialscanarbitrarilybecategorisedasflowableanduni- versal composites. Each variety has unique chemical, Fig. 6_The bonding agent, OptiBond XTR primer, followed by the adhesive, is copiously applied to both enamel and dentine, according to the manufacture’s instructions. Fig. 7_The appropriate shade of SonicFill deep resin is dispensed into the cavity using the handpiece, ensuring that the Unidose tip is totally submerged in the material to avoid entrapment of air. Fig. 8_After the tip is removed, the SonicFill resin regains its high viscosity to allow sculpting, in this instance, a flat shape CompoRoller carving tip is used for creating cuspal inclines. Fig. 9_A conical shaped CompoRoller carving tip is used for refining occlusal fissures. I 13 special topic _ composite restorations I cosmeticdentistry 1_2013 Fig. 6 Fig. 8Fig. 7 Fig. 9 Low viscosity Medium viscosity Varying viscosity Final capping layer Surefill SDR Flow (Dentsply) Initial lining layer Single increment QuixFil (Dentsply) Tetric EvoCream Bulk Fill (Ivolcar-Vivadent) x-Tra Fill (Voco) Venus Bulk Fill (Heraeus) SonicFill (Kerr/Kavo) 4 mm4 mm 5 mm Bulk-fill Compromise sculptability Compromise adaptability No lining or capping layers Illustration