Base:
cement placed under a dental restoration to insulate the pulp (nerve chamber)

Bicuspid or pre-molar:
transitional teeth behind the cuspids

Bifurcation (trifurcation):
juncture of two (three) roots in posterior teeth

Biopsy:
removal of a small piece of tissue for microscopic examination

Bite:
relationship of the upper and lower teeth on closure (occlusion)

Bite wings:
caries (decay) detection x-rays

Black hairy tongue:
elongated papillae on the tongue, promoting the growth of microorganisms

Bleaching:
chemical or laser treatment of natural teeth for whitening effect

Block injection:
anesthesia of a nerve trunk that covers a large area of the jaw; a mandibular block injection produce numbness of the lower jaw, teeth, half the tongue

Bonding:
adhesive dental restoration technique; a tooth-colored composite resin to repair and/or change the color or shape of a tooth

Bone resorption:
decrease in bone supporting the roots of teeth; a common result of periodontal (gum disease)

Braces:
devices used by orthodontists to gradually reposition teeth to a more favorable alignment

Bridge:
stationary dental prosthesis (appliance) fixed to teeth adjacent to a space; replaces one or more missing teeth, cemented or bonded to supporting teeth or implants adjacent to the space

Bruxism:
grinding or gnashing of the teeth, most commonly while the patient is asleep

Bruxomania:
persistent "nervous" grinding of the teeth while the patient is awake