Description

3M ESPE Filtek LS Low Shrink Posterior Restorative System is a light-cured, radiopaque composite with 55% by volume of inorganic fillers. It is indicated for direct posterior restorations. The composite is based on new resin chemistry, silorane, which minimizes polymerization shrinkage. Polymerization shrinkage is an inherent property of current resin composites based on dimethacrylate chemistry. As the resin is cured, the molecules move toward each other to form a polymer network. This reaction results in significant volume contraction. The polymerization process of Filtek LS occurs by a ring-opening reaction that results in lower polymerization shrinkage compared to the methacrylate-based resins. The LS System Adhesive Self-Etch Primer and Bond have been designed to provide a strong bond to the Filtek LS composite. The primer is placed on the tooth surface and light cured, followed by the application of the bond which is then light cured. The composite is available in shades A2, A3, B2, and C3 in syringes and unit-dose capsules and has a working time of up to six minutes. Both the composite and adhesive can be cured by a halogen or LED light. Thirteen editors evaluated 3M ESPE Filtek LS Low Shrink Posterior Restorative System in over 400 restorations. This product received an 86% clinical rating.

Editors’ Observations

Manufacturer’s Instructions/Packaging
The kit is nicely packaged and contains all the necessary materials for restoration placement including a shade guide, dispensing brushes and wells. Technique guides are included along with detailed instructions.

Ease of Dispensing and Placement
The composite can be dispensed with very little pressure from either the syringes or capsules. Metal or plastic instruments can be used to manipulate the material into the cavity preparation. The working time of the composite is up to six minutes, which allows it to be manipulated under full operatory light illumination. Each increment should not exceed 2.5 mm. Both the primer and bond bottles need to be shaken before dispensing. Both liquids can be easily expressed as individual drops, minimizing the amount of product dispensed for each procedure.

Viscosity of Adhesive
The viscosity of the primer and bond liquids results in uniform and complete coverage of the tooth surface.

Ease of Air Dispersal and Lack of Pooling
A gentle stream of air spreads the primer and the bond to an even film. Pooling was not evident unless too much material was placed in the preparation.

Ease of Band Removal
The adhesive did not stick to metal matrix bands and they could be removed with little effort.

Time Required for Bonding
Applying and curing the primer and bond separately took longer than many adhesive systems, and the consultants rated that as a negative feature.

Packability/Sculptability/Non-Stickiness
The composite can be packed to produce good proximal contacts and anatomical form. This feature is enhanced by the fact that the composite does not stick to the placement instruments. The material can be manipulated with no noticeable slumping.

Shade Match Before and After Curing
The limited available shades compromise the ability to match all tooth shades; however, the supplied shades match well. The shades are slightly opaque but they blend adequately with tooth structure.

Quality of Polish and Esthetics
The consultants commented that polishing and finishing this composite was difficult. Excess material was hard to remove and it took considerable time to produce a smooth surface.

Lack of Post-operative Sensitivity
There were no reports of post-operative sensitivity during the evaluation period.

Clinical Tips

• Filtek LS is not compatible with conventional adhesive systems.
• LS System Adhesive cannot be used with composites other than Filtek LS.
• A plasma ARC light cannot be used to cure this product.