Sebaceous gland Sebaceous gland Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. In humans, they occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. The type of secretion of the sebaceous glands is referred to as holocrine. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Fordyce
Dental sealant have this chalky appearance, the etching process must be repeated. The sealant is then applied to the tooth by carefully placing the sealant material into the prepared pits and fissures by using a disposable instrument provided by the manufacturer. Overfilling on the tooth should be prevented to minimize occlusal adjustment. The material is left for 10 seconds after the placement prior to curing to allow optimum penetration of the sealant material into the pores created by the etching procedure. Finally, the sealant is hardened by a curing light, which usually takes 20 to 30 seconds. Glass ionomer does not require