Gingivally, the depth of a class V cavity is typically 0.75-1 mm. This depth is sufficient to provide a good bond with the tooth structure and prevent microleakage without causing significant gingival irritation or damage.

Natural glaze is often more durable and permanent compared to applied artificial glaze, providing a better finish.

The distance between the tip of the curing light and the tooth is important, as the intensity  of the light source is important. A minimum of 400-mW/cm2 is required. It is recommended that the tip be placed as close to the surface to be cured as is physically possible (within 1 to 2mm).

The intensity of light is inverselyproportional to the distance from the source. As a general rule each increment should be at most 1.5 to 2 mm thick. This will ensure complete penetration of the light and maximum curing of thecomposite at the bottom most portion of the cavity preparation.

Explanation: The outline form of a Class V cavity preparation is primarily determined by the extent of carious tissue. The goal is to remove all carious dentin while preserving as much healthy tooth structure as possible. The outline form must encompass the entire area affected by caries to ensure that the restoration is effective and durable. Other factors, such as the height of the gingival crest, type of restorative material, and tooth anatomy, may influence the preparation but are secondary to the extent of caries.

The upper limit of urinary mercury attributed to extensive amalgam restoration is typically considered to be 4 micrograms/g of creatinine. While the actual limit can vary based on the individual and the extent of amalgam fillings, a level of 4 micrograms/g of creatinine is commonly used as a benchmark for evaluating potential health concerns related to mercury exposure from dental amalgam.