**Core Concept**
Zinc phosphate cement is a widely used dental restorative material, but its anticariogenic properties make it a preferred choice for certain clinical applications, particularly when placed around bands on molars to prevent caries. This is due to the presence of zinc ions, which have been shown to inhibit the growth of Streptococcus mutans, a primary caries-causing bacterium.

**Why the Correct Answer is Right**
The anticariogenic effect of zinc phosphate cement is attributed to the release of zinc ions, which bind to the bacterial cell wall and inhibit the production of extracellular polysaccharides, thereby reducing the formation of dental plaque and caries. Additionally, zinc ions have been shown to have a direct bactericidal effect on Streptococcus mutans, further contributing to its anticariogenic properties.

**Why Each Wrong Option is Incorrect**
**Option A:** Zinc oxide-eugenol cement is not as effective in preventing caries as zinc phosphate cement, as it contains eugenol, which can be toxic to pulpal tissues and may actually contribute to caries formation.

**Option B:** Polycarboxylate cement does not have significant anticariogenic properties, as it does not release ions that can inhibit bacterial growth or reduce caries formation.

**Option C:** Glass-ionomer cement has some anticariogenic properties due to the release of fluoride ions, but it is not as effective as zinc phosphate cement in preventing caries around bands on molars.

**Clinical Pearl / High-Yield Fact**
When selecting a cement for placing bands on molars, remember that zinc phosphate cement is the most anticariogenic option due to its release of zinc ions, which can help prevent caries formation.

**Correct Answer:** C. Zinc phosphate cement.