Australian Dental Council (ADC) Practice Test 2026 - Free ADC Practice Questions and Study Guide

The correct answer highlights that methyl methacrylate is known for its significant volume shrinkage when polymerized compared to other common monomers. When methyl methacrylate undergoes polymerization, the transition from monomer to polymer involves a change in volume due to the rearrangement of molecular structures. This property is crucial in dental applications, particularly in the formulation of dental resins used for restorations, as it can affect the fit and integrity of the restoration.

Methyl methacrylate has a high polymerization shrinkage because it is a small molecule that, upon curing, turns into a polymer with a more structured arrangement. This shrinkage can lead to gaps between the restoration and the tooth structure if not properly managed, impacting the overall success of dental procedures.

In contrast, epoxy resins and polyurethanes typically have lower volume shrinkage due to their unique chemical properties and the way they cure. Polylactic acid, while used in some dental applications, is primarily a biodegradable polymer, and its shrinkage characteristics during polymerization do not rival those of methyl methacrylate in dental contexts.