Re: Combining Technologies to Improve Aesthetics

[sushantpatel_doc]

CASE REPORT 1
The “Updated” Closed Sandwich Technique

The “closed sandwich” technique refers to the use of a GI cement base or liner, covering internal dentinal areas of a cavity preparation only. A total rim of cavosurface enamel remains around the entire preparation, and this will be treated with a total-etch protocol, thus sealing the margins with an adhesive resin.
The patient seen in Figure 1 presented for replacement of direct composite restorations on teeth Nos. 18 and 19. The existing composite restorations were removed with an Er, Cr, YSGG all-tissue laser (BIOLASE Technologies) and the preparations refined with a super course 5855-016 round tapered diamond bur (Brasseler USA) along with any recurrent caries (Figure 2). The restorative plan, after isolation of the operative area (Isolite [Isolite Systems]), was to base any deep areas of the preparation with a GI cement.
First, the preparation was conditioned by performing a 2-second etch with 37% phosphoric acid (Figure 3), followed by a thorough water rinse (Figure 4). (An alternative technique would be to use Cavity Conditioner [GC America] for 10 seconds, and then rinse with water.) The GI cement capsule (Fuji IX) was activated/mixed per manufacturers’ instructions and then syringed directly into the cavity preparations (Figure 5). A nonserrated amalgam plugger (HuFriedy Plugger PLGOR4) was used to gently pack the GI cement into the floor of the preparation as necessary and the material was allowed to set. Excess material was then removed using a bur (10839-016 end-cutting diamond bur [Brasseler USA]) and high-speed handpiece (Figure 6), recreating the “ideal” internal form to the cavity preparation (Figure 7). The Fuji IX Extra material was left in the deeply excavated areas of the preparation.
The cavosurface enamel was then etched with 37% phosphoric acid for 10 to 15 seconds (Figure 8), and rinsed with water. The excess moisture was evacuated using a high volume suction, using care not to desiccate any remaining dentin that was not covered by the Fuji IX base. It is important not to overdessicate dentin when placing a GI cement liner or base since the material can draw moisture from the dentinal tubules leading to possible sensitivity issues for some patients. If the tooth is desiccated from the air-drying process, it can be rewetted using a desensitizer (AcQuaseal B [AcQuaMed Technologies]) (Figure 9).

The bonding resin (G-Bond [GC America]) was then placed into the cavity preparation (Figure 10) and agitated with the microbrush (Figure 11) to ensure penetration into the demineralized tooth structure. Air spray was directed across the cavity preparation to evaporate the solvent (carrier) (Figure 12), and then the adhesive was light-cured for 20 seconds (Figure 13). Next, a thin layer of flowable composite (Gradia Lo-Flo [GC America]) was placed on the floor of the preparation and dispersed with an explorer to ensure uniform/complete coverage of all surfaces (Figure 14), and light-cured (Figure 15).
Next, the composite restorative material (Kalore) was incrementally placed (Figure 16) using a plugger and a plastic filling instrument (PLGOR4 and Flexithin Mini 4, respectively [HuFriedy]) to sculpt proper occlusal form into the restoration (Figure 17). An artist’s brush dipped in resin, then thoroughly dried with a 2×2 gauze, can be used to further smooth and adapt the composite material at the cavosurface margins. This step will reduce the amount of marginal finishing with carbide burs due to the excellent adaptation of the resin-tooth interface. After light-curing, the isolation device was removed and the occlusion was checked with articulating paper (Parkell Accufilm 2 1/1000 inch thick).
A minor adjustment was made using an interproximal composite finishing diamond (8392-016 interproximal finishing needle) (Figure 18), and the restoration was polished using medium and fine rubber abrasive polishing points (Jiffy polishers and brushes [Ultradent Products]) (Figure 19).
The final polishing step was accomplished using an Occlubrush (Kerr Hawe). Next, the restoration was re-etched, rinsed, dried, and an application of composite surface sealant (G-Coat Plus [GC America]) was applied with a brush (Figure 20). Finally, the sealant material was light-cured (Figure 21), completing the restorative process. The final photo image (Figure 22) shows the completed restorations of teeth Nos. 18 and 19.
Figures 23 to 25 show another “closed sandwich” case restored with the Kalore composite resin. Note the immediate high luster that was achieved after a minimal number of polishing steps. The 6-month follow-up photo shows excellent retention of the polished surface.