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89-510: Three basic types of loupes exist: Loupes are used in many professions where magnification enables precision work to be done with greater efficiency and ease. Examples include surgery, dentistry , ophthalmology , the jewelry trade, gemology , questioned document examination and watchmaking . Loupes are also sometimes used in photography and printing. Jewellers typically use a monocular , handheld loupe to magnify gemstones and other jewelry that they wish to inspect. A 10× magnification

178-642: A Tang dynasty medical text written by the Chinese physician Su Kung in 659, and appeared in Germany in 1528. During the Islamic Golden Age Dentistry was discussed in several famous books of medicine such as The Canon in medicine written by Avicenna and Al-Tasreef by Al-Zahrawi who is considered the greatest surgeon of the Middle Ages , Avicenna said that jaw fracture should be reduced according to

267-668: A continuous spectrum . Incandescent bulbs are highly inefficient, in that just 2–5% of the energy consumed is emitted as visible, usable light . The remaining 95% is lost as heat . In warmer climates, the emitted heat must then be removed, putting additional pressure on ventilation or air conditioning systems. In colder weather, the heat byproduct has some value, and has been successfully harnessed for warming in devices such as heat lamps . Incandescent bulbs are nonetheless being phased out in favor of technologies like CFLs and LED bulbs in many countries due to their low energy efficiency. The European Commission estimated in 2012 that

356-420: A filament heated white-hot by electric current , gas-discharge lamps , which produce light by means of an electric arc through a gas, such as fluorescent lamps , and LED lamps , which produce light by a flow of electrons across a band gap in a semiconductor . The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of

445-402: A grow light to aid in plant growth especially in indoor hydroponics and aquatic plants with recent research into the most effective types of light for plant growth. Due to their nonlinear resistance characteristics, tungsten filament lamps have long been used as fast-acting thermistors in electronic circuits. Popular uses have included: In Western culture, a lightbulb — in particular,

534-401: A light table . Typical magnifications for viewing slides full-frame depend on image format; 35 mm frames (24×36 mm slides to 38×38 mm superslides) are best viewed at ca. 5×, while ca. 3× is optimal for viewing medium format slides (6×4.5 cm / 6×6 cm / 6×7 cm). Often, a 10× loupe is used to examine critical sharpness. Photographers using large format cameras may use

623-581: A monochromatic orange-yellow light, which gives a similarly monochromatic perception of any illuminated scene. For this reason, it is generally reserved for outdoor public lighting applications. Low-pressure sodium lights are favoured for public lighting by astronomers, since the light pollution that they generate can be easily filtered, contrary to broadband or continuous spectra. Many lamp units, or light bulbs, are specified in standardized shape codes and socket names. Incandescent bulbs and their retrofit replacements are often specified as " A19 /A60 E26 /E27",

712-484: A better design. The rivalry between Swan and Edison eventually led to a merger, forming the Edison and Swan Electric Light Company . By the early twentieth century these had completely replaced arc lamps . The turn of the century saw further improvements in bulb longevity and efficiency, notably with the introduction of the tungsten filament by William D. Coolidge , who applied for a patent in 1912. This innovation became

801-531: A bid to incorporate the school. Studies show that dentists that graduated from different countries, or even from different dental schools in one country, may make different clinical decisions for the same clinical condition. For example, dentists that graduated from Israeli dental schools may recommend the removal of asymptomatic impacted third molar (wisdom teeth) more often than dentists that graduated from Latin American or Eastern European dental schools. In

890-429: A century of continuous and incremental improvement, including numerous designs, patents, and resulting intellectual property disputes, to get from these early experiments to commercially produced incandescent light bulbs in the 1920s. In 1840, Warren de la Rue enclosed a platinum coil in a vacuum tube and passed an electric current through it, thus creating one of the world's first electric light bulbs . The design

979-449: A common size for those kinds of light bulbs. In this example, the "A" parameters describe the bulb size and shape within the A-series light bulb while the "E" parameters describe the Edison screw base size and thread characteristics. Common comparison parameters include: Less common parameters include color rendering index (CRI). Life expectancy for many types of lamp is defined as

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1068-414: A complete ban on incandescent bulbs would contribute 5 to 10 billion euros to the economy and save 15 billion metric tonnes of carbon dioxide emissions . Halogen lamps are usually much smaller than standard incandescent lamps, because for successful operation a bulb temperature over 200 °C is generally necessary. For this reason, most have a bulb of fused silica (quartz) or aluminosilicate glass. This

1157-648: A few countries, to become a qualified dentist one must usually complete at least four years of postgraduate study; Dental degrees awarded around the world include the Doctor of Dental Surgery (DDS) and Doctor of Dental Medicine (DMD) in North America (US and Canada), and the Bachelor of Dental Surgery/Baccalaureus Dentalis Chirurgiae (BDS, BDent, BChD, BDSc) in the UK and current and former British Commonwealth countries. All dentists in

1246-422: A glass or silica envelope containing two metal electrodes separated by a gas. Gases used include, neon , argon , xenon , sodium , metal halides , and mercury . The core operating principle is much the same as the carbon arc lamp, but the term "arc lamp" normally refers to carbon arc lamps, with more modern types of gas discharge lamp normally called discharge lamps. With some discharge lamps, very high voltage

1335-635: A loupe to view the ground glass image to aid in focusing. Users of digital single-lens reflex cameras use loupes to help to identify dust and other particles on the sensor, in preparation for sensor cleaning. Dentists , hygienists , and dental therapists typically use binocular loupe glasses since they need both hands free when performing dental procedures. The magnification helps with accurate diagnoses of oral conditions and enhances surgical precision when completing treatment. Additionally, loupes can improve dentists' posture which can decrease occupational strain. Some dental loupes are flip-type, which take

1424-477: A pain point for doctors who need to physically strain, bending over and looking down, to treat their patients. Over time this posture results in discomfort, pain, and even neuromuscular disease. Some modern loupes address this by incorporating refractive prisms which alter the course of the light through the telescopes, so that the dentist can maintain a neutral, upright position with eyes relaxed and looking straight ahead. A typical magnification for use in dentistry

1513-548: A remarkable achievement for the period. Major advances in science were made in the 19th century, and dentistry evolved from a trade to a profession. The profession came under government regulation by the end of the 19th century. In the UK, the Dentist Act was passed in 1878 and the British Dental Association formed in 1879. In the same year, Francis Brodie Imlach was the first ever dentist to be elected President of

1602-529: A standard for incandescent bulbs for many years. In 1910, Georges Claude introduced the first neon light, paving the way for neon signs which would become ubiquitous in advertising. In 1934, Arthur Compton , a renowned physicist and GE consultant, reported to the GE lamp department on successful experiments with fluorescent lighting at General Electric Co., Ltd. in Great Britain (unrelated to General Electric in

1691-421: A substantial premium over coins with slight wear. This wear cannot always be seen with the naked eye. Numismatists can also employ loupes to identify some counterfeit coins that would pass a naked-eye visual inspection. Loupes are similarly used for evaluating other collectable objects, such as trading cards and antiques . Conservators often use hand held loupes or head-mounted binocular magnifiers such as

1780-459: Is 2.5×, but dental loupes can be anywhere in the range from 2× to 8×. Optimal magnification is a function of the type of work the doctor does - namely, how much detail he or she needs to see, taking into consideration that when magnification increases, the field of view decreases. As a tool that sits on the face and is used for hours at a time, weight is also a significant factor in considering the type of loupes to use. Together with proper access to

1869-905: Is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. Fluorescent lamp fixtures are more costly than incandescent lamps, because they require a ballast to regulate the current through the lamp, but the lower energy cost typically offsets the higher initial cost. Compact fluorescent lamps are available in the same popular sizes as incandescent lamps and are used as an energy-saving alternative in homes. Because they contain mercury, many fluorescent lamps are classified as hazardous waste . The United States Environmental Protection Agency recommends that fluorescent lamps be segregated from general waste for recycling or safe disposal, and some jurisdictions require recycling of them. The solid-state light-emitting diode (LED) has been popular as an indicator light in consumer electronics and professional audio gear since

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1958-461: Is a movement in modern dentistry to place a greater emphasis on high-quality scientific evidence in decision-making. Evidence-based dentistry (EBD) uses current scientific evidence to guide decisions. It is an approach to oral health that requires the application and examination of relevant scientific data related to the patient's oral and medical health. Along with the dentist's professional skill and expertise, EBD allows dentists to stay up to date on

2047-458: Is a vital geological field tool used to identify small mineral crystals and structures in rocks. Loupes are an essential tool in both numismatics , the study of currency, and the related practice of coin collection . Coin collectors frequently employ loupes for better evaluation of the quality of their coins, since identifying surface wear is vital when attempting to classify the grade of a coin. Uncirculated coins (coins without wear) can command

2136-498: Is considered to have stemmed from the trade of barber surgeons . Dental treatments are carried out by a dental team, which often consists of a dentist and dental auxiliaries (such as dental assistants , dental hygienists , dental technicians , and dental therapists ). Most dentists either work in private practices ( primary care ), dental hospitals, or ( secondary care ) institutions (prisons, armed forces bases, etc.). The modern movement of evidence-based dentistry calls for

2225-698: Is exposed to sound levels above 90 dBA according to the Occupational Safety and Health Administration (OSHA). Regulations state that the permissible noise exposure levels for individuals is 90 dBA. For the National Institute for Occupational Safety and Health ( NIOSH ), exposure limits are set to 85 dBA. Exposures below 85 dBA are not considered to be hazardous. Time limits are placed on how long an individual can stay in an environment above 85 dBA before it causes hearing loss. OSHA places that limitation at 8 hours for 85 dBA. The exposure time becomes shorter as

2314-464: Is good to use for inspecting jewelry and hallmarks and is the Gemological Institute of America 's standard for grading diamond clarity . Stones will sometimes be inspected at higher magnifications than 10×, although the depth of field and field of view become too small to be instructive. The accepted standard for grading diamonds is therefore that inclusions and blemishes visible at 10× impact

2403-409: Is often also understood to subsume the now largely defunct medical specialty of stomatology (the study of the mouth and its disorders and diseases) for which reason the two terms are used interchangeably in certain regions. However, some specialties such as oral and maxillofacial surgery (facial reconstruction) may require both medical and dental degrees to accomplish. In European history, dentistry

2492-465: Is often sealed inside an additional layer of glass. The outer glass is a safety precaution, to reduce ultraviolet emission and to contain hot glass shards should the inner envelope explode during operation. Oily residue from fingerprints may cause a hot quartz envelope to shatter due to excessive heat buildup at the contamination site. The risk of burns or fire is also greater with bare bulbs, leading to their prohibition in some places, unless enclosed by

2581-601: Is part of the larger movement toward evidence-based medicine and other evidence-based practices , especially since a major part of dentistry involves dealing with oral and systemic diseases. Other issues relevant to the dental field in terms of evidence-based research and evidence-based practice include population oral health, dental clinical practice, tooth morphology etc. Dentistry is unique in that it requires dental students to have competence-based clinical skills that can only be acquired through supervised specialized laboratory training and direct patient care. This necessitates

2670-837: Is referred to as "oral-systemic health". John M. Harris started the world's first dental school in Bainbridge, Ohio , and helped to establish dentistry as a health profession. It opened on 21 February 1828, and today is a dental museum . The first dental college, Baltimore College of Dental Surgery , opened in Baltimore, Maryland, US in 1840. The second in the United States was the Ohio College of Dental Surgery , established in Cincinnati, Ohio, in 1845. The Philadelphia College of Dental Surgery followed in 1852. In 1907, Temple University accepted

2759-557: Is sufficient for cities to be easily visible at night from the air, and from space. External lighting grew at a rate of 3–6 percent for the later half of the 20th century and is the major source of light pollution that burdens astronomers and others with 80% of the world's population living in areas with night time light pollution. Light pollution has been shown to have a negative effect on some wildlife. Electric lamps can be used as heat sources, for example in incubators , as infrared lamps in fast food restaurants and toys such as

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2848-407: Is the deciding factor, such as street lighting. More advanced electronic ballasts may be designed to maintain constant light output over the life of the lamp, may drive the lamp with a square wave to maintain completely flicker-free output, and shut down in the event of certain faults. The most efficient source of electric light is the low-pressure sodium lamp. It produces, for all practical purposes,

2937-443: Is the most common form of artificial lighting . Lamps usually have a base made of ceramic , metal, glass, or plastic which secures the lamp in the socket of a light fixture , which is often called a "lamp" as well. The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet mount . The three main categories of electric lights are incandescent lamps, which produce light by

3026-412: Is too high diagnosis becomes difficult due to the small field of view. Ideal magnification for diagnostic purposes is up to 2×. Treatment of dental caries, periodontal disease, and pulpal disease are all aided by magnification. The dental specialty of endodontics has performed the vast majority of research regarding magnification in dentistry. Because the identification of accessory canals in addition to

3115-615: Is used to strike the arc. This requires an electrical circuit called an igniter, which is part of the electrical ballast circuitry. After the arc is struck, the internal resistance of the lamp drops to a low level, and the ballast limits the current to the operating current. Without a ballast, excess current would flow, causing rapid destruction of the lamp. Some lamp types contain a small amount of neon, which permits striking at normal running voltage with no external ignition circuitry. Low-pressure sodium lamps operate this way. The simplest ballasts are just an inductor, and are chosen where cost

3204-415: Is useful for lighting designers , because of its low power consumption, low heat generation, instantaneous on/off control, and in the case of single color LEDs, continuity of color throughout the life of the diode and relatively low cost of manufacture. LED lifetime depends strongly on the temperature of the diode. Operating an LED lamp in conditions that increase the internal temperature can greatly shorten

3293-495: The oral mucosa . Dentistry may also encompass other aspects of the craniofacial complex including the temporomandibular joint . The practitioner is called a dentist . The history of dentistry is almost as ancient as the history of humanity and civilization, with the earliest evidence dating from 7000 BC to 5500 BC. Dentistry is thought to have been the first specialization in medicine which has gone on to develop its own accredited degree with its own specializations. Dentistry

3382-485: The 14th century, Guy de Chauliac most probably invented the dental pelican (resembling a pelican 's beak) which was used to perform dental extractions up until the late 18th century. The pelican was replaced by the dental key which, in turn, was replaced by modern forceps in the 19th century. The first book focused solely on dentistry was the "Artzney Buchlein" in 1530, and the first dental textbook written in English

3471-437: The 1870s for large building and street lighting until it was superseded in the early 20th century by the incandescent light. Carbon arc lamps operate at high power and produce high intensity white light. They also are a point source of light. They remained in use in limited applications that required these properties, such as movie projectors , stage lighting , and searchlights , until after World War II. A discharge lamp has

3560-509: The 1900s the Phoebus cartel formed in an attempt to reduce the life of electric light bulbs, an example of planned obsolescence . Some types of lamp are also sensitive to switching cycles. Rooms with frequent switching, such as bathrooms, can expect much shorter lamp life than what is printed on the box. Compact fluorescent lamps are particularly sensitive to switching cycles. The total amount of artificial light (especially from street light )

3649-455: The 1970s. In the 2000s, efficacy and output have risen to the point where LEDs are now being used in lighting applications such as car headlights and brake lights, in flashlights and bicycle lights, as well as in decorative applications, such as holiday lighting. Indicator LEDs are known for their extremely long life, up to 100,000 hours, but lighting LEDs are operated much less conservatively, and consequently have shorter lives. LED technology

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3738-504: The 19th century. Modern electric light sources come in a profusion of types and sizes adapted to many applications. Most modern electric lighting is powered by centrally generated electric power, but lighting may also be powered by mobile or standby electric generators or battery systems. Battery -powered light is often reserved for when and where stationary lights fail, often in the form of flashlights or electric lanterns , as well as in vehicles. Before electric lighting became common in

3827-522: The 5th century BC. The Phoenicians crafted dentures during the 6th–4th century BC, fashioning them from gold wire and incorporating two ivory teeth. In ancient Egypt, Hesy-Ra is the first named "dentist" (greatest of the teeth). The Egyptians bound replacement teeth together with gold wire. Roman medical writer Cornelius Celsus wrote extensively of oral diseases as well as dental treatments such as narcotic-containing emollients and astringents . The earliest dental amalgams were first documented in

3916-464: The Diseases but of single Parts, it must needs be a barren Profession to confine unto that of drawing of Teeth, and little better than to have been Tooth-drawer unto King Pyrrhus, who had but two in his Head. The French surgeon Pierre Fauchard became known as the "father of modern dentistry". Despite the limitations of the primitive surgical instruments during the late 17th and early 18th century, Fauchard

4005-532: The Kenner Easy-Bake Oven . Lamps can also be used for light therapy to deal with such issues as vitamin D deficiency , skin conditions such as acne and dermatitis , skin cancers , and seasonal affective disorder . Lamps which emit a specific frequency of blue light are also used to treat neonatal jaundice with the treatment which was initially undertaken in hospitals being able to be conducted at home. Electric lamps can also be used as

4094-522: The Optivisor to examine artifacts and documents requiring cleaning or repair. Dentistry Dentistry , also known as dental medicine and oral medicine , is the branch of medicine focused on the teeth , gums , and mouth . It consists of the study, diagnosis , prevention, management, and treatment of diseases , disorders, and conditions of the mouth, most commonly focused on dentition (the development and arrangement of teeth) as well as

4183-811: The Paleolithic, around 13,000 years ago, points to bitumen used to fill a tooth and in Neolithic Slovenia, 6500 years ago, beeswax was used to close a fracture in a tooth. The Indus valley has yielded evidence of dentistry being practised as far back as 7000 BC, during the Stone Age . The Neolithic site of Mehrgarh (now in Pakistan's south western province of Balochistan ) indicates that this form of dentistry involved curing tooth related disorders with bow drills operated, perhaps, by skilled bead-crafters. The reconstruction of this ancient form of dentistry showed that

4272-492: The Royal College of Surgeons (Edinburgh), raising dentistry onto a par with clinical surgery for the first time. Long term occupational noise exposure can contribute to permanent hearing loss, which is referred to as noise-induced hearing loss (NIHL) and tinnitus . Noise exposure can cause excessive stimulation of the hearing mechanism, which damages the delicate structures of the inner ear. NIHL can occur when an individual

4361-605: The UK than there were in 1921. It was between 1650 and 1800 that the science of modern dentistry developed. The English physician Thomas Browne in his A Letter to a Friend ( c.  1656 pub. 1690) made an early dental observation with characteristic humour: The Egyptian Mummies that I have seen, have had their Mouths open, and somewhat gaping, which affordeth a good opportunity to view and observe their Teeth, wherein 'tis not easie to find any wanting or decayed: and therefore in Egypt, where one Man practised but one Operation, or

4450-787: The United Kingdom became fully regulated with the 1921 Dentists Act, which required the registration of anyone practising dentistry. The British Dental Association , formed in 1880 with Sir John Tomes as president, played a major role in prosecuting dentists practising illegally. Dentists in the United Kingdom are now regulated by the General Dental Council . In many countries, dentists usually complete between five and eight years of post-secondary education before practising. Though not mandatory, many dentists choose to complete an internship or residency focusing on specific aspects of dental care after they have received their dental degree. In

4539-615: The United Kingdom, the first dental schools, the London School of Dental Surgery and the Metropolitan School of Dental Science, both in London, opened in 1859. The British Dentists Act of 1878 and the 1879 Dentists Register limited the title of "dentist" and "dental surgeon" to qualified and registered practitioners. However, others could legally describe themselves as "dental experts" or "dental consultants". The practice of dentistry in

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4628-773: The United States undergo at least three years of undergraduate studies, but nearly all complete a bachelor's degree. This schooling is followed by four years of dental school to qualify as a " Doctor of Dental Surgery " (DDS) or " Doctor of Dental Medicine " (DMD). Specialization in dentistry is available in the fields of Anesthesiology, Dental Public Health, Endodontics, Oral Radiology, Oral and Maxillofacial Surgery, Oral Medicine, Orofacial Pain, Pathology, Orthodontics, Pediatric Dentistry (Pedodontics), Periodontics, and Prosthodontics. Some dentists undertake further training after their initial degree in order to specialize. Exactly which subjects are recognized by dental registration bodies varies according to location. Examples include: Tooth decay

4717-552: The United States). Stimulated by this report, and with all of the key elements available, a team led by George E. Inman built a prototype fluorescent lamp in 1934 at General Electric 's Nela Park (Ohio) engineering laboratory. This was not a trivial exercise; as noted by Arthur A. Bright, "A great deal of experimentation had to be done on lamp sizes and shapes, cathode construction, gas pressures of both argon and mercury vapor, colors of fluorescent powders, methods of attaching them to

4806-512: The associated scientific study of teeth is odontology (from Ancient Greek : ὀδούς , romanized :  odoús , lit.   'tooth') – the study of the structure, development, and abnormalities of the teeth. Dentistry usually encompasses practices related to the oral cavity. According to the World Health Organization , oral diseases are major public health problems due to their high incidence and prevalence across

4895-416: The carbon rods are short-lived and require constant adjustment in use, as the intense heat of the arc erodes them. The lamps produce significant ultraviolet output, they require ventilation when used indoors, and due to their intensity they need protection from direct sight. Invented by Humphry Davy around 1805, the carbon arc was the first practical electric light. It was used commercially beginning in

4984-498: The chances of a successful tooth transplant (initially, at least) would be improved if the donor tooth was as fresh as possible and was matched for size with the recipient. These principles are still used in the transplantation of internal organs . Hunter conducted a series of pioneering operations, in which he attempted a tooth transplant. Although the donated teeth never properly bonded with the recipients' gums, one of Hunter's patients stated that he had three which lasted for six years,

5073-547: The clarity grade. The inclusions in VVS diamonds are hard to find even at 10×. Loupes are employed to assist watchmakers in assembling mechanical watches. Many aspects require the use of the loupe, in particular the assembly of the watch mechanism itself, the assembly and details of the watch dial, as well as the formation of the watch strap and installation of precious stones onto the watch face. Analog ( film ) photographers use loupes to review, edit or analyze negatives and slides on

5162-701: The conventional wall-mounted or table-top light source or a belt clip rechargeable battery pack. Options for loupe-mounted cameras and video recorders are also available. Surgeons in many specialties commonly use loupes when doing surgery on delicate structures. The loupes used by surgeons are mounted in the lenses of glasses and are custom made for the individual surgeon, taking into account their corrected vision, interpupillary distance and desired focal distance. Multiple magnification powers are available. They are most commonly used in otolaryngology , neurosurgery , ophthalmology , plastic surgery , cardiac surgery , orthopedic surgery , and vascular surgery . The loupe

5251-455: The dBA level increases. Within the field of dentistry, a variety of cleaning tools are used including piezoelectric and sonic scalers, and ultrasonic scalers and cleaners. While a majority of the tools do not exceed 75 dBA, prolonged exposure over many years can lead to hearing loss or complaints of tinnitus. Few dentists have reported using personal hearing protective devices, which could offset any potential hearing loss or tinnitus. There

5340-444: The early 20th century, people used candles , gas lights , oil lamps , and fires . In 1799–1800, Alessandro Volta created the voltaic pile , the first electric battery. Current from these batteries could heat copper wire to incandescence. Vasily Vladimirovich Petrov developed the first persistent electric arc in 1802, and English chemist Humphry Davy gave a practical demonstration of an arc light in 1806. It took more than

5429-460: The eruption pattern of teeth, treating decayed teeth and gum disease, extracting teeth with forceps , and using wires to stabilize loose teeth and fractured jaws. Use of dental appliances, bridges and dentures was applied by the Etruscans in northern Italy, from as early as 700 BC, of human or other animal teeth fastened together with gold bands. The Romans had likely borrowed this technique by

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5518-444: The form of two small cylinders, one in front of each lens of the glasses. Other types are inset within the lens of the glasses. Dental caries, also known as cavities, are most accurately identified by visual and tactile examination of a clean, dry tooth. Magnification enables dentists to improve their ability to differentiate between a stain and a cavity. Cavities are rated and scored based on their visual presentation. If magnification

5607-555: The globe, with the disadvantaged affected more than other socio-economic groups. The majority of dental treatments are carried out to prevent or treat the two most common oral diseases which are dental caries (tooth decay) and periodontal disease (gum disease or pyorrhea). Common treatments involve the restoration of teeth , extraction or surgical removal of teeth, scaling and root planing , endodontic root canal treatment, and cosmetic dentistry By nature of their general training, dentists, without specialization can carry out

5696-488: The groundwork for future innovations such as those by Thomas Edison. The late 1870s and 1880s were marked by intense competition and innovation, with inventors like Joseph Swan in the UK and Thomas Edison in the US independently developing functional incandescent lamps. Swan's bulbs, based on designs by William Staite, were successful, but the filaments were too thick. Edison worked to create bulbs with thinner filaments, leading to

5785-461: The home if broken and widespread problems with proper disposal of mercury-containing bulbs. In its modern form, the incandescent light bulb consists of a coiled filament of tungsten sealed in a globular glass chamber, either a vacuum or full of an inert gas such as argon . When an electric current is connected, the tungsten is heated to 2,000 to 3,300 K (1,730 to 3,030 °C; 3,140 to 5,480 °F) and glows, emitting light that approximates

5874-599: The inside of the tube, and other details of the lamp and its auxiliaries before the new device was ready for the public." The first practical LED arrived in 1962. In the United States , incandescent light bulbs including halogen bulbs stopped being sold as of August 1, 2023, because they do not meet minimum lumens per watt performance metrics established by the U.S. Department of Energy . Compact fluorescent bulbs are also banned despite their lumens per watt performance because of their toxic mercury that can be released into

5963-429: The lamp's life. Some lasers have been adapted as an alternative to LEDs to provide highly focused illumination. Carbon arc lamps consist of two carbon rod electrodes in open air, supplied by a current-limiting ballast . The electric arc is struck by touching the rod tips then separating them. The ensuing arc produces a white-hot plasma between the rod tips. These lamps have higher efficacy than filament lamps, but

6052-531: The latest procedures and patients to receive improved treatment. A new paradigm for medical education designed to incorporate current research into education and practice was developed to help practitioners provide the best care for their patients. It was first introduced by Gordon Guyatt and the Evidence-Based Medicine Working Group at McMaster University in Ontario, Canada in the 1990s. It

6141-406: The luminaire. Those designed for 12- or 24-volt operation have compact filaments, useful for good optical control. Also, they have higher efficacies (lumens per watt) and longer lives than non-halogen types. The light output remains almost constant throughout their life. Fluorescent lamps consist of a glass tube that contains mercury vapour or argon under low pressure. Electricity flowing through

6230-584: The majority of dental treatments such as restorative (fillings, crowns , bridges ), prosthetic ( dentures ), endodontic (root canal) therapy, periodontal (gum) therapy, and extraction of teeth, as well as performing examinations, radiographs (x-rays), and diagnosis. Dentists can also prescribe medications used in the field such as antibiotics , sedatives , and any other drugs used in patient management. Depending on their licensing boards, general dentists may be required to complete additional training to perform sedation, dental implants, etc. Dentists also encourage

6319-565: The methods used were reliable and effective. The earliest dental filling , made of beeswax , was discovered in Slovenia and dates from 6500 years ago. Dentistry was practised in prehistoric Malta , as evidenced by a skull which had a dental abscess lanced from the root of a tooth dating back to around 2500 BC. An ancient Sumerian text describes a " tooth worm " as the cause of dental caries . Evidence of this belief has also been found in ancient India, Egypt , Japan, and China. The legend of

6408-455: The mouth to inspect teeth deformity or oral malaises, haematology (study of blood) to avoid bleeding complications during dental surgery, cardiology (due to various severe complications arising from dental surgery with patients with heart disease), etc. The term dentistry comes from dentist , which comes from French dentiste , which comes from the French and Latin words for tooth. The term for

6497-430: The need for a scientific and professional basis of care with a foundation of extensive research-based education. According to some experts, the accreditation of dental schools can enhance the quality and professionalism of dental education. Lamp (electrical component) This is an accepted version of this page An electric light , lamp , or light bulb is an electrical component that produces light . It

6586-410: The number of hours of operation at which 50% of them fail, that is the median life of the lamps. Production tolerances as low as 1% can create a variance of 25% in lamp life, so in general some lamps will fail well before the rated life expectancy, and some will last much longer. For LEDs, lamp life is defined as the operation time at which 50% of lamps have experienced a 70% decrease in light output. In

6675-619: The occlusal guidance of the teeth; this principle is still valid in modern times. Al-Zahrawi invented over 200 surgical tools that resemble the modern kind. Historically, dental extractions have been used to treat a variety of illnesses. During the Middle Ages and throughout the 19th century, dentistry was not a profession in itself, and often dental procedures were performed by barbers or general physicians . Barbers usually limited their practice to extracting teeth which alleviated pain and associated chronic tooth infection . Instruments used for dental extractions date back several centuries. In

6764-438: The oral cavity, light is an important part of performing precision dentistry. Because a dentist's head often eclipses the overhead dental lamp, loupes may be fitted with a light source. Loupe-mounted lights used to be fed by fiber optic cables that connected to either a wall-mounted or table-top light source. Newer models feature a more convenient LED lamp within the loupe-mounted light and an electric cord coming from either

6853-550: The prevention of oral diseases through proper hygiene and regular, twice or more yearly, checkups for professional cleaning and evaluation. Oral infections and inflammations may affect overall health and conditions in the oral cavity may be indicative of systemic diseases, such as osteoporosis , diabetes , celiac disease or cancer . Many studies have also shown that gum disease is associated with an increased risk of diabetes, heart disease , and preterm birth . The concept that oral health can affect systemic health and disease

6942-682: The primary pulp canals is essential to complete nonsurgical root canal therapy, magnification provides dentists enhanced visualization to locate and treat more obscured canals. Treatment of periodontal disease is achieved by removing calculus deposits, plaque and therefore bacteria which causes inflammation and subsequently bone destruction. In severe cases, surgery to reduce pocket depth is indicated. Periodontists and hygienists must visualize plaque and calculus to remove it. Magnification can assist dentists and hygienists with identification and removal of plaque and calculus in addition to improving visualization for periodontal surgery. Ergonomics have long been

7031-405: The teeth and in the gums could appear in the later stages of tooth decay. Fauchard was the pioneer of dental prosthesis , and he invented many methods to replace lost teeth. He suggested that substitutes could be made from carved blocks of ivory or bone . He also introduced dental braces , although they were initially made of gold, he discovered that the teeth position could be corrected as

7120-433: The teeth would follow the pattern of the wires. Waxed linen or silk threads were usually employed to fasten the braces. His contributions to the world of dental science consist primarily of his 1728 publication Le chirurgien dentiste or The Surgeon Dentist. The French text included "basic oral anatomy and function, dental construction, and various operative and restorative techniques, and effectively separated dentistry from

7209-510: The treatment of dislocated or fractured jaws. In the 18th century BC, the Code of Hammurabi referenced dental extraction twice as it related to punishment. Examination of the remains of some ancient Egyptians and Greco-Romans reveals early attempts at dental prosthetics . However, it is possible the prosthetics were prepared after death for aesthetic reasons. Ancient Greek scholars Hippocrates and Aristotle wrote about dentistry, including

7298-419: The tube causes the gases to give off ultraviolet energy. The inside of the tubes are coated with phosphors that give off visible light when struck by ultraviolet photons . They have much higher efficiency than incandescent lamps. For the same amount of light generated, they typically use around one-quarter to one-third the power of an incandescent. The typical luminous efficacy of fluorescent lighting systems

7387-475: The use of high-quality scientific research and evidence to guide decision-making such as in manual tooth conservation, use of fluoride water treatment and fluoride toothpaste, dealing with oral diseases such as tooth decay and periodontitis , as well as systematic diseases such as osteoporosis , diabetes , celiac disease , cancer , and HIV/AIDS which could also affect the oral cavity. Other practices relevant to evidence-based dentistry include radiology of

7476-573: The wider category of surgery". After Fauchard, the study of dentistry rapidly expanded. Two important books, Natural History of Human Teeth (1771) and Practical Treatise on the Diseases of the Teeth (1778), were published by British surgeon John Hunter . In 1763, he entered into a period of collaboration with the London-based dentist James Spence. He began to theorise about the possibility of tooth transplants from one person to another. He realised that

7565-662: The worm is also found in the Homeric Hymns , and as late as the 14th century AD the surgeon Guy de Chauliac still promoted the belief that worms cause tooth decay. Recipes for the treatment of toothache, infections and loose teeth are spread throughout the Ebers Papyrus , Kahun Papyri , Brugsch Papyrus , and Hearst papyrus of Ancient Egypt . The Edwin Smith Papyrus , written in the 17th century BC but which may reflect previous manuscripts from as early as 3000 BC, discusses

7654-412: Was a highly skilled surgeon who made remarkable improvisations of dental instruments, often adapting tools from watchmakers , jewelers and even barbers , that he thought could be used in dentistry. He introduced dental fillings as treatment for dental cavities . He asserted that sugar -derived acids like tartaric acid were responsible for dental decay , and also suggested that tumors surrounding

7743-491: Was based on the concept that the high melting point of platinum would allow it to operate at high temperatures and that the evacuated chamber would contain fewer gas molecules to react with the platinum, improving its longevity. Although it was an efficient design, the cost of the platinum made it impractical for commercial use. William Greener , an English inventor, made significant contributions to early electric lighting with his lamp in 1846 (patent specification 11076), laying

7832-508: Was called "Operator for the Teeth" by Charles Allen in 1685. In the United Kingdom, there was no formal qualification for the providers of dental treatment until 1859 and it was only in 1921 that the practice of dentistry was limited to those who were professionally qualified. The Royal Commission on the National Health Service in 1979 reported that there were then more than twice as many registered dentists per 10,000 population in

7921-496: Was low in pre-agricultural societies, but the advent of farming society about 10,000 years ago correlated with an increase in tooth decay (cavities). An infected tooth from Italy partially cleaned with flint tools, between 13,820 and 14,160 years old, represents the oldest known dentistry, although a 2017 study suggests that 130,000 years ago the Neanderthals already used rudimentary dentistry tools. In Italy evidence dated to

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