What type of tray is best suited for an impression of half of the dental arch?

A quadrant tray is specifically designed to capture an impression of half of the dental arch, making it the most suitable choice for this scenario. Its shape and size allow it to comfortably accommodate the contours of only one side of the dental arch, which enhances accuracy and detail in the impression taken. This is particularly important in achieving a precise fit for procedures that will involve only half of the arch, such as restorations, partial dentures, or orthodontic applications.

Using a full arch tray would not be as effective since it is intended to capture the entire dental arch, possibly leading to unnecessary material being used and could complicate the impression process for just half of the arch. Similarly, a 5x5 tray, which typically describes a specific size that may not correspond with common configurations for capturing dental impressions, may not fit correctly. A plastic tray, while lightweight and easy to use, does not inherently have the specific design features needed for precise half-arch impressions, unless it is specifically designed as a quadrant tray. Thus, the quadrant tray stands out as the ideal option for this task.