Aqw Teeth

[Beltran Mathews]

Brushat least twice a day. If you can, brush after every meal. Ideally wait 30 minutes after eating; this will allow any enamel that softened from acid during eating to re-harden and not get brushed away. Brushing removes plaque, a film of bacteria that clings to teeth. When bacteria in plaque come into contact with food, they produce acids. These acids lead to cavities. To brush:

Floss teeth at least once a day. Flossing gets rid of food and plaque between the teeth, where your toothbrush cannot reach. If plaque stays between teeth, it can harden into tartar, which must be removed by a dentist or hygienist. To floss:

Mouthwashes do more than just freshen your breath. Rinse with an antiseptic mouthwash at least once a day to kill bacteria that cause plaque and early gum disease. A fluoride rinse can help prevent tooth decay and cavities. Some rinses can do both.

For good dental health, eat a variety of foods, but minimize those that contain sugars and starches. These foods produce the most acids in the mouth, and the longer they stay in the mouth, the more they can damage the teeth. Hard "sucking candies" are especially harmful because they stay in the mouth a long time.

Visit your dentist at least once every 6 months. To keep your teeth and gums healthy, it's important to have regular check-ups and professional cleanings. You should also see your dentist if you have pain in your teeth, pain in your mouth, or bleeding, swollen gums.

Human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. As such, they are considered part of the human digestive system.[1] Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla (upper jaw) or the mandible (lower jaw) and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.

Humans, like most other mammals, are diphyodont, meaning that they develop two sets of teeth. The first set, deciduous teeth, also called "primary teeth", "baby teeth", or "milk teeth", normally eventually contains 20 teeth. Primary teeth typically start to appear ("erupt") around six months of age and this may be distracting and/or painful for the infant. However, some babies are born with one or more visible teeth, known as neonatal teeth or "natal teeth".

Dental anatomy is a field of anatomy dedicated to the study of tooth structure. The development, appearance, and classification of teeth fall within its field of study, though dental occlusion, or contact between teeth, does not. Dental anatomy is also a taxonomic science as it is concerned with the naming of teeth and their structures. This information serves a practical purpose for dentists, enabling them to easily identify and describe teeth and structures during treatment.

The anatomic crown of a tooth is the area covered in enamel above the cementoenamel junction (CEJ) or "neck" of the tooth.[2][3] Most of the crown is composed of dentin ("dentine" in British English) with the pulp chamber inside.[4] The crown is within bone before eruption.[5] After eruption, it is almost always visible. The anatomic root is found below the CEJ and is covered with cementum. As with the crown, dentin composes most of the root, which normally has pulp canals. Canines and most premolars, except for maxillary first premolars, usually have one root. Maxillary first premolars and mandibular molars usually have two roots. Maxillary molars usually have three roots. Additional roots are referred to as supernumerary roots.

Most teeth have identifiable features that distinguish them from others. There are several different notation systems to refer to a specific tooth. The three most common systems are the FDI World Dental Federation notation (ISO 3950), the Universal Numbering System, and the Palmer notation. The FDI system is used worldwide, the Universal only in the United States, while the older Palmer notation still has some adherents only in the United Kingdom.

There are small differences between the teeth of males and females, with male teeth along with the male jaw tending to be larger on average than female teeth and jaw. There are also differences in the internal dental tissue proportions, with male teeth consisting of proportionately more dentine while female teeth have proportionately more enamel.[7]

Enamel is the hardest and most highly mineralized substance of the body. It has its origin from oral ectoderm. It is one of the four major tissues which make up the tooth, along with dentin, cementum, and dental pulp.[8] It is normally visible and must be supported by underlying dentin. 96% of enamel consists of mineral, with water and organic material comprising the rest.[9] The normal color of enamel varies from light yellow to grayish white. At the edges of teeth where there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Since enamel is semitranslucent, the color of dentin and any restorative dental material underneath the enamel strongly affects the appearance of a tooth. Enamel varies in thickness over the surface of the tooth and is often thickest at the cusp, up to 2.5mm, and thinnest at its border, which is seen clinically as the CEJ.[10] The wear rate of enamel, called attrition, is 8 micrometers a year from normal factors.[11]

Enamel's primary mineral is hydroxyapatite, which is a crystalline calcium phosphate.[12] The large amount of minerals in enamel accounts not only for its strength but also for its brittleness.[10] Dentin, which is less mineralized and less brittle, compensates for enamel and is necessary as a support.[12] Unlike dentin and bone, enamel does not contain collagen. Proteins of note in the development of enamel are ameloblastins, amelogenins, enamelins and tuftelins. It is believed that they aid in the development of enamel by serving as framework support, among other functions.[13] In rare circumstances enamel can fail to form, leaving the underlying dentine exposed on the surface.[14]

Dentin is the substance between enamel or cementum and the pulp chamber. It is secreted by the odontoblasts of the dental pulp.[15] The formation of dentin is known as dentinogenesis. The porous, yellow-hued material is made up of 70% inorganic materials, 20% organic materials, and 10% water by weight.[16] Because it is softer than enamel, it decays more rapidly and is subject to severe cavities if not properly treated, but dentin still acts as a protective layer and supports the crown of the tooth.

Dentin is a mineralized connective tissue with an organic matrix of collagenous proteins. Dentin has microscopic channels, called dentinal tubules, which radiate outward through the dentin from the pulp cavity to the exterior cementum or enamel border.[17] The diameter of these tubules range from 2.5 μm near the pulp, to 1.2 μm in the midportion, and 900 nm near the dentino-enamel junction.[18] Although they may have tiny side-branches, the tubules do not intersect with each other. Their length is dictated by the radius of the tooth. The three dimensional configuration of the dentinal tubules is genetically determined.

There are three types of dentin, primary, secondary and tertiary.[19] Secondary dentin is a layer of dentin produced after root formation and continues to form with age. Tertiary dentin is created in response to stimulus, such as cavities and tooth wear.[20]

The dental pulp is the central part of the tooth filled with soft connective tissue.[16] This tissue contains blood vessels and nerves that enter the tooth from a hole at the apex of the root.[23] Along the border between the dentin and the pulp are odontoblasts, which initiate the formation of dentin.[16] Other cells in the pulp include fibroblasts, preodontoblasts, macrophages and T lymphocytes.[24] The pulp is commonly called "the nerve" of the tooth.

Tooth development is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. Although many diverse species have teeth, their development is largely the same as in humans. For human teeth to have a healthy oral environment, enamel, dentin, cementum, and the periodontium must all develop during appropriate stages of fetal development. Primary teeth start to form in the development of the embryo between the sixth and eighth weeks, and permanent teeth begin to form in the twentieth week.[25] If teeth do not start to develop at or near these times, they will not develop at all.

A significant amount of research has focused on determining the processes that initiate tooth development. It is widely accepted that there is a factor within the tissues of the first pharyngeal arch that is necessary for the development of teeth.[26]

Tooth development is commonly divided into the following stages: the bud stage, the cap, the bell, and finally maturation. The staging of tooth development is an attempt to categorize changes that take place along a continuum; frequently it is difficult to decide what stage should be assigned to a particular developing tooth.[26] This determination is further complicated by the varying appearance of different histologic sections of the same developing tooth, which can appear to be different stages.

The tooth bud (sometimes called the tooth germ) is an aggregation of cells that eventually forms a tooth. It is organized into three parts: the enamel organ, the dental papilla and the dental follicle.[27] The enamel organ is composed of the outer enamel epithelium, inner enamel epithelium, stellate reticulum and stratum intermedium.[27] These cells give rise to ameloblasts, which produce enamel and the reduced enamel epithelium. The growth of cervical loop cells into the deeper tissues forms Hertwig's Epithelial Root Sheath, which determines a tooth's root shape. The dental papilla contains cells that develop into odontoblasts, which are dentin-forming cells.[27] Additionally, the junction between the dental papilla and inner enamel epithelium determines the crown shape of a tooth.[28] The dental follicle gives rise to three important cells: cementoblasts, osteoblasts, and fibroblasts. Cementoblasts form the cementum of a tooth. Osteoblasts give rise to the alveolar bone around the roots of teeth. Fibroblasts develop the periodontal ligaments which connect teeth to the alveolar bone through cementum.[29]

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