What is true about a modified preparation for an anterior composite restoration?

The correct choice highlights that the prepared walls in a modified preparation for an anterior composite restoration are designed with a 45-degree bevel relative to the uncut tooth structure. This beveling technique is significant because it enhances bonding effectiveness. By sloping the walls at a 45-degree angle, you increase the surface area available for bonding agents, which promotes better adhesion between the composite material and the enamel.

The bevel also helps with aesthetics by allowing for a smoother transition between the composite restoration and the natural tooth, creating a more visually pleasing result. This approach aids in masking the distinct line where the restoration meets the tooth, contributing to an overall more harmonious appearance.

In contrast to the other options, while 90-degree angles can provide structural integrity in some scenarios, they do not offer the same bonding advantages as the bevel does. A bevel also does not inherently reduce the number of rods for etching. Instead, it enhances the etching process by increasing the effectiveness of enamel conditioning. Lastly, the 90-degree bevel would not typically be regarded as an ideal option for esthetic blending, as it could create a noticeable line rather than seamlessly merging the restoration with the tooth.