Once the teeth have been “blasted”, rinsed and dried it’s time to place the Bioclear matrix in the mesial and distal positions. Tuck the matrix beneath the rubber dam by using the rigid Bioclear explorer to ensure a perfect subgingival matrix/tooth interface or margin. After placement, in some cases the Bioclear matrices overlap on the facial. If this occurs, trim them back to leave a small gap between the two matricies which allows for venting of excess injection moulded composite.
Once the tooth is isolated with the Bioclear matrix as seen in Fig. 6, the stage is set for injection molding. The tooth is acid etched, rinsed and dried. Then Scotchbond Universal adhesive (3M) is placed using a mop type brush (Fig. 7). Air thin the Scotchbond Universal adhesive to drive off the solvent and prevent pooling, especially at the gingival interface. It is important to note that at this stage, since there is no exposed dentin present, the adhesive is NOT light cured, only air thinned.
Then heated Filtek Supreme Ultra Flowable followed with heated Filtek Supreme paste (3M) are injected slowly and under pressure into the anatomic space formed by the two matrices - each step being helped by the previous step to keep flowing smoothly. It is important to follow one with the other relatively quickly as cooling of the composite takes place within the first 20-30 seconds. Overfilling the matrix space is part of the technique as this allows room for cutback when shaping and polishing.
The clinical convenience with this technique is that the matrix will always seal itself off subgingivally, often eliminating the need to finish or polish the restoration with burs in the interproximal area afterwards.
Both the flowable and paste composites are heated to the optimal temperature of 158 degrees F or 70 degrees C using the Bioclear HeatSync Composite Warmer (Fig. 8). Numerous studies have shown the benefits and the safety of heating composites resins prior to use in the mouth, (Fig. 5-7) Interestingly, Filtek is now, as of 2020, the only composite resin to be approved by the FDA for use in its heated state. Some of the other benefits of the Filtek resin for the Bioclear Method are: the exact color match between the flowable and the paste composite (not a guarantee with every company), the nanotechnology of the Filtek resin filler and it’s superior polishability.
Heating both the flowable and paste resin eases the advance of material (by making it more liquid) into the small, sometimes tight spaces where the matrix- tooth interface is at too acute of an angle for room temperature paste composite. After matrix removal, that trusted mylar finish is left intact and in contact with the gingival tissue. This allows for the beautiful newly established curvature to be easily flossed and sets the stage for future good gingival health (see radiograph Fig 9).