Which type of resin restoration is considered to be the longest lasting?

The longest lasting type of resin restoration is typically classified as Class III. This classification refers to restorations that occur on the proximal surfaces of anterior teeth, specifically between incisors and canines. Class III restorations often involve less occlusal stress compared to Class I restorations (which are on the chewing surfaces) and Class II restorations (which are on the proximal surfaces of posterior teeth). As a result, Class III restorations are generally subjected to lower forces and have a more favorable environment for the longevity of the resin material used.

Moreover, the design of Class III restorations focuses on bonding to enamel and dentin, creating a strong adhesion that contributes to their durability. The aesthetic considerations for anterior teeth also prompt the use of high-quality resin materials that can withstand wear while maintaining their appearance over time.

In contrast, Class I and Class II restorations face higher occlusal forces and wear due to their locations and functions in chewing, which can compromise their longevity. Class IV restorations involve the incisors and canines as well, but they typically deal with more extensive defects that might expose the restoration to greater stress over time. Thus, Class III restorations, when properly placed and maintained, often yield the best outcomes in terms of longevity