Below:

Abscess __ pus_filled, inflamed area around a tooth
Amalgam __ silver_mercury alloy used to fill cavities
Bicuspid __ adult type of tooth located between the front teeth (incisors and canines) and the back teeth (molars). These teeth are used for crushing and mashing food, with two on the top and two on the bottom of each side of the mouth.
Bonding __ process that first etches the tooth's enamel, and then uses resin to attach tooth_colored fillings or veneers to a tooth
Bridge __ nonremovable replacement for one or more missing teeth, anchored by teeth on either side of the gap. Bridges restore chewing ability and prevent neighboring teeth from shifting, which can result in a poor bite and gum disease.
Bruxism __ habitual, unconscious clenching of the jaw and/or grinding of the teeth. Approximately one in four adults grinds their teeth, usually while asleep or under stress. This problem can cause headaches and tooth damage.
Calculus __ hardened or calcified plaque that sticks to the teeth and causes decay and gum disease. Also called tartar, it requires scaling by a dentist or dental hygienist to remove.
Caries __ a word that means "rottenness" in Latin, this is the gradual decay and disintegration of a tooth. The decay can affect the tooth's soft or bony tissues.
Cavity __ hole or weak area in a tooth, caused by tooth decay (caries)
Composites __ tooth_colored materials used as fillings or bonding to restore teeth. Most are made of resin, a plastic mixture filled with ground_up "glass" particles (silicon dioxide).
Crown ("cap") __ part of the tooth that's visible above the gum, or the artificial substitute for it. A restorative crown covers the top part of a tooth that is severely damaged or weakened by decay. A crown is made of metal, resin, porcelain, or porcelain_covered metal, and cemented onto the tooth.
Cuspid __ pointy tooth, also called a canine (for their resemblance to dogs' fangs), located on either side of the incisors, the four teeth in the very front of the mouth. Adults have four cuspids that are used to tear food, two on the top and two on the bottom.
Dentin __ middle layer of the tooth, below the enamel and surrounding the pulp
Dry socket __ painful condition following a tooth extraction caused by a blood clot that does not properly fill the empty socket, leaving the bone underneath exposed to air and food
Enamel __ hard, white outer layer of a tooth. Enamel is the hardest substance in the body.
Endontist __ dentist who specializes in endodontics, or the treatment of the root and nerve system in teeth
Fluoride __ chemical compound added to toothpaste and drinking water that helps strengthen and repair the surface of teeth and prevent cavities
Gingivitis __ inflammation of the gums often caused by a buildup of food particles and plaque (a sticky film containing bacteria) on and around the teeth
Gum disease __ illnesses that inflame and, if untreated, can destroy the gum tissues and bones that support and anchor teeth
Halitosis __ bad breath, which can be caused or worsened by a dry mouth, poor dental hygiene, bacteria mixed with putrifying food particles in the mouth, sinus problems, or other conditions.
Impacted tooth __ any tooth (but especially a wisdom tooth) that cannot break through the gum into normal position because it is growing against or blocked by bone, soft tissue, or another tooth
Incisor __ type of tooth located at the front of the mouth. Adults have eight of these flat teeth (four on the top and four on the bottom), and they are used primarily to bite and cut food.
Malocclusion __ condition in which the upper and lower teeth do not fit together properly. An overbite is a common example of a malocclusion.
Molar __ type of tooth located in the back of the mouth behind the bicuspids. Adults have eight molars (12 if they still have their wisdom teeth), which have a flat bumpy surface good for the toughest chewing jobs.
Mucin __ protein found in the saliva that mixes with sugars to form bacterial plaque
Orthodontist __ dentist who specializes in orthodontics, or the correction of misaligned teeth and jaws with braces, retainers, or other dental appliances.
Pedodontist __ dentist who specializes in pedodontics, or dentistry for children
Periodontist __ dentist who specializes in periodontics, or the treatment of the gums, soft tissues, and bones that support the teeth
Periodontal Disease __ any gum disease (such as periodontitis or gingivitis) that, if untreated, inflames and eventually destroys the bone and tissues that support and anchor the teeth.
Plaque __ sticky, colorless film containing bacteria that forms on teeth and causes tooth decay and gum disease if it is not removed by brushing and flossing.
Prosthodontist __ dentist who specializes in prosthodontics, or the restoration and replacement of missing teeth with artificial materials
Pulp __ innermost layer of the tooth, below the enamel and dentin, which contains the nerves and blood vessels
Pulpitis __ inflammation of the pulp (the tooth's innermost layer) caused by a cavity or other trauma, and often signalled by a painful toothache
Radiograph __ x_ray
Root Canal (endodontic treatment) __ procedure in which the diseased nerve (also called the pulp or inside core) of a heavily decayed or damaged tooth is removed and the central pulp space of the tooth is filled and sealed with dental cement
Tartar (calculus) __ hard deposit, or calcified bacterial plaque, which sticks to the teeth and causes decay. See Calculus.
Wisdom teeth __ Back teeth, also called third molars, that usually come in between the ages of 15 to 25. In ancient times, humans needed these teeth to chew and grind raw food, but today many people have them removed because they are hard to clean, which in turn can lead to infection, or because there is no room in the jaw for these teeth to grow in straight.