Sweet and Sour Liquid Candy Effect on Sound Enamel Surfaces: In Vitro SEM Study

Objectives: This in vitro scanning electron microscopic (SEM) study evaluated effect of sweet and sour liquid candy popular among children of Mexican heritage on sound enamel surfaces.
Methods: 10 human extracted molar teeth with sound enamel surfaces were sectioned into 4 portions. Each tooth portion was assigned to a treatment group: 1) No treatment control; 2) Slurry of Lucas Gusano Tamarind Flavored Liquid Mexican Candy and synthetic saliva (Liquid Candy Slurry) for 10 minutes exposure period; 3) twice daily Liquid Candy Slurry for 10 minutes for 14 days with fresh synthetic saliva (SS) rinsing between exposure intervals; and 4) twice daily Liquid Candy Slurry for 10 minutes followed by casein phosphopeptide-amorphous calcium agent with fluoride (CPP-ACP-FL, MI Plus Paste, GC America, Alsip IL) for 2 minutes for 14 days with fresh SS rinsing between exposure periods. The tooth portions underwent scanning electron microscopy.
Results: No Treatment Control Group showed intact enamel surfaces with occasional surface depressions representing enamel prism endings. Sound enamel exposure to Liquid Candy Slurry without SS rinsing resulted in dramatic enamel surface loss and underlying enamel structure exposure with etched enamel prisms resembling those seen with acid-etching techniques for bonding dental materials. This also resulted in markedly porous enamel surfaces. Occasional areas with fine globular material attached to the etched enamel prisms and enamel surface were observed. With Liquid Candy Slurry exposure followed by SS rinsing resulted in partial to near complete masking of etched enamel surfaces by porous surface coatings with frequent clefting of coatings. With Liquid Candy Slurry exposure followed by CPP-ACP-FL treatment and then SS rinsing, etched enamel surfaces showed more uniform, less porous surface coatings with occasional areas with partially occluded enamel prism-like structures.
Conclusions: Sweet and sour liquid candy slurry induces enamel loss and porosities similar to that described for acid etching employed in bonding dental materials. SS restores acid damaged enamel surface to a certain extent. Treatment with CPP-ACP-FL following liquid candy slurry exposure appeared to provide more uniform, less porous enamel surface coatings, and may facilitate remineralization of acid-damaged enamel surfaces.