How is materia alba primarily attached to tooth surfaces?

Materia alba is primarily a soft, white accumulation of bacteria, food particles, and dead cells that can be found on the surfaces of teeth, particularly in areas that are less accessible to oral hygiene practices. The nature of its attachment to tooth surfaces can be described as loosely attached. This means that it can be easily displaced through mechanical actions such as brushing or rinsing.

Unlike plaque, which adheres more firmly to the tooth surface due to its biofilm structure, materia alba is less organized and tends to sit on top of the tooth surface, making it more susceptible to removal. This characteristic distinction helps in managing oral hygiene, as thorough brushing can effectively eliminate materia alba, thereby preventing its buildup from progressing into more serious oral health issues.

The other options relate to aspects of oral biofilms or residues but do not accurately describe the nature of materia alba's attachment to the teeth. Tightly attached or completely dissolved do not reflect the more transient and removable nature of this material, while attachment via plaque suggests a stronger, more cohesive relationship than actually exists.