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A dental laser is a type of laser designed specifically for use in oral surgery or dentistry. In the United States, the use of lasers on the gums was first approved by the Food and Drug Administration in the early 1990s, and use on hard tissue like teeth or the bone of the mandible gained approval in 1996. Several variants of dental lasers are in use with different wavelengths and these mean they are better suited for different applications. 

How Do Lasers Work in Dentistry?

All lasers work by delivering energy in the form of light. When used for surgical and dental procedures, the laser acts as a cutting instrument or a vaporizer of tissue that it comes in contact with. When used for "curing" a filling, the laser helps to strengthen the bond between the filling and the tooth. When used in teeth-whitening procedures, the laser acts as a heat source and enhances the effect of tooth-bleaching agents. 

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  Lasers have been used in dentistry since 1994 to treat a number of dental problems. Yet, despite FDA approval, no laser system has received the American Dental Association's (ADA) Seal of Acceptance as an alternative to more traditional treatment. This seal ensures dentists that the product or device meets ADA standards for safety and effectiveness, among other things. The ADA, however, states that it is cautiously optimistic about the role of laser technology in the field of dentistry. These lasers are different from cold lasers used in phototherapy to relieve headaches, pain and inflammation.  

 Still, some dentists are using lasers to treat:

  • Tooth decay. Lasers are used to remove decay within a tooth and prepare the surrounding enamel for receipt of the filling.
  • Gum disease. Lasers are used to reshape gums and remove bacteria during root canal procedures.
  • Biopsy or lesion removal. Lasers can be used to remove a small piece of tissue (called a biopsy) so that it can be examined for cancer. Lasers are also used to remove lesions in the mouth and relieve the pain of canker sores.
  • Teeth whitening. Lasers are used to speed up in-office teeth whitening procedures. A peroxide bleaching solution, applied to the toothsurface, is ''activated" by laser energy, which speeds up of the whitening process.

Soft tissue lasers

 

Diode lasers 

Carbon dioxide lasers 

Nd:YAG laser

Diode lasers wavelengths in the 810–1,100 nm range are poorly absorbed by the soft tissues such as the gingivae, and cannot be used for soft tissue cutting or ablation. Instead, the distal end of diode’s glass fiber is charred (by burned ink or by burned corkwood, etc.) and the char is heated by the 810-1,100 nm laser beam, which in turn heats up the glass fiber’ tip. The soft tissue is cut, on contact, by the hot charred glass tip and not by the laser beam. Similarly ND:YAG lasers are used for soft tissue surgeries in the oral cavity, such as gingivectomy, periodontal sulcular debridement, LANAP, frenectomy, biopsy, and coagulation of graft donor sites. The Nd:YAG laser wavelength are partially absorbed by pigment in the tissue such as hemoglobin and melanin. These lasers are often used for debridement and disinfection of periodontal pockets. Their coagulative ability to form fibrin allows them to seal treated pockets. The CO2 laser remains the best surgical laser for the soft tissue where both cutting and hemostasis is achieved photo-thermally (radiantly).

Soft and hard tissue lasers

 

Er:YAG laser 

Carbon dioxide laser 

Er,Cr:YSGG laser 

Erbium lasers are both hard and soft tissue capable. They can be used for a host of dental procedures, and allow for more procedures to be done without local anesthesia. Erbium lasers can be used for hard tissue procedures like bone cutting and create minimal thermal and mechanical trauma to adjacent tissues. These procedures show an excellent healing response. Soft tissue applications with erbium lasers feature less hemostasis and coagulation abilities relative to the CO2 lasers. The new CO2 laser operating at 9,300 nm features strong absorption in both soft and hard tissue and is the newest alternative to erbium lasers.


 All-Tissue Dental Lasers are essential for a variety of procedures. In addition to Pediatric and General Dentistry, these hard and soft tissue dental lasers are ideal for Periodontics, Prosthetic/Esthetic dentistry and Endodontics. The main lasers used for hard and soft tissues of the mouth are Er,Cr:YSGG, Er:YAG and Nd:YAG; although most products feature one type, there are a few that boast both Er:YAG and Nd:YAG. Most hard/soft tissue dental lasers are portable, allowing easy transfer throughout a dental practice. Many lasers are controlled via foot operation and some even feature LCD touch screens for ease of use. Although there is a high initial investment, as dental technology and procedures advance, the cost of performing these procedures without lasers is much higher. Without the use of a drill or anesthesia, the dental laser drastically improves patient comfort, which helps increase ROI. 

Laser surgery

  Laser surgery is a type of surgery that uses a laser (in contrast to using a scalpel) to cut tissue. Examples include the use of a laser scalpel in otherwise conventional surgery, and soft-tissue laser surgery, in which the laser beam vaporizes soft tissue with high water content. Laser resurfacing is a technique in which covalent bonds of a material are dissolved by a laser, a technique invented by aesthetic plastic surgeon Thomas L. Roberts, III using CO2 lasers in the 1990s.The CO2 (carbon dioxide) laser remains the gold standard for the soft tissue surgery because of the ease of simultaneous photo-thermal ablation and coagulation (and small blood capillary hemostasis). Laser surgery is commonly used on the eye. Techniques used include LASIK, which is used to correct near and far-sightedness in vision, and photorefractive keratectomy, a procedure which permanently reshapes the cornea using an excimer laser to remove a small amount of the human tissue. Types of surgical lasers include carbon dioxide, argon, Nd:YAG laser, and Potassium titanyl phosphate, from among others.  

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Soft Tissue Applications of Dental Lasers

 

  • Gingivoplasty (gingival recontouring or shaping)
  • Gingivectomy
  • Frenectomy / frenotomy
  • Implant uncovering
  • Gingival troughing / retraction
  • Exposing subgingival caries
  • Fibroma removal
  • Sulcular debridement
  • Biopsies incisional and excisional
  • Aphthous ulcer treatment
  • Relief of pain from soft tissue irritations
  • Soft tissue crown lengthening
  • Soft tissue incisions and excisions
  • Flap surgery
  • Vestibuloplasty / frenuloplasty
  • Hemostasis assistance / control
  • Hasten clotting of bleeding caused by other procedures
  • Incising and draining abscesses
  • Operculectomy
  • Oral papillectomy
  • Reduction / removal of hyperplastic tissue
    • Denture epulis
    • Drug–induced gingival hyperplasia
  • Removal of postsurgical granulomas
  • Exposure of unerupted teeth
  • Destruction (ablation) of lesions
  • Distal / proximal wedge procedure
  • Excision of pericoronal gingiva
  • Soft tissue crown lengthening

Considerations when Selecting a Laser

 

  • Wavelength
  • Peak power
  • Emission / duty cycle
  • Pulse modes
  • Minimum and maximum pulse width
  • Size
  • Portability
  • Ergonomics
  • Device cost
  • Per treatment cost
  • Infection control protocols
  • User interface
  • Energy delivery system
  • Individual user profiles
  • Availability of device–specific training and the cost
  • Manufacturer’s dependability and stability

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Hard tissue laser procedures.

 A more conservative, less invasive treatment of the carious lesion has intrigued researchers and clinicians for decades. With over 170 million restorations placed worldwide each year, many of which could be treated using a laser, there exists an increasing need for understanding hard tissue laser procedures. An historical review of past scientific and clinical hard research, biophysics, and histology are discussed. A complete review of present applications and procedures along with their capabilities and limitations will give the clinician a better understanding. Clinical case studies, along with guidelines for tooth preparation and hard tissue laser applications and technological advances for diagnosis and treatment will give the clinician a look into the future. 

Dental caries removal

 In September 2016 the Cochrane collaboration published a systematic review of the current evidence comparing the use of lasers for caries removal, in both deciduous and adult teeth, with the standard dental drill. Nine trials were reviewed, published between 1998 and 2014, with 662 participants in total. These included three different types of laser: Er:YAG; Er,Cr:YSGG; and Nd:YAG. Overall the quality of evidence available was found to be low, and the authors were unable to recommend one method of caries removal over the other. There was no evidence of a difference between the marginal integrity or durability of the restorations placed. However, there was some evidence that the laser produced less pain and required less anaesthesia than the drill. The authors concluded that more research is required. 

Cost of lasers

 Use of the dental laser remains limited, with cost and effectiveness being the primary barriers. The cost of a dental laser ranges from $4,000 to $130,000, where a pneumatic dental drill costs between $200 and $500. The lasers are also incapable of performing some routine dental operations. 

Benefits of lasers

 Dental lasers are not without their benefits, though, as the use of a laser can decrease morbidity after surgery, and reduces the need for anesthetics. Because of the cauterization of tissue there will be little bleeding following soft tissue procedures, and some of the risks of alternative electrosurgery procedures are avoided. 

Laser technology overview for general dentists

Lasers have been used in dentistry for more than 20 years. We have gone from treating only soft tissue to treating hard tissues such as teeth and bone. The cost of soft-tissue lasers has decreased along with their size. General dentists can now easily integrate lasers into their practices.

Laser is an acronym that stands for Light Amplification by Stimulated Emission of Radiation. Light is measured in wavelengths. Dental laser wavelengths are Diodes 830-1,064nm, Nd:YAG 1,064nm, Erbium 2,790-2,940nm, and CO2 9.3-10.6nm. Every wavelength has a specific thermal output and specific tissue interaction that is always predictable. The different wavelengths for dental lasers perform different procedures. The most common dental lasers go by acronyms that are associated with how the laser light is produced. They include Diode, Nd:YAG, Er:YAG, or CO2. The dental laser manufacturers give the lasers names, but in many cases the wavelength of the laser is identical to another. It then becomes about the customization of the hardware and the number of parameters a dentist wants to control.

There are a few basics for using lasers safely. Laser eye safety is extremely important and should never be compromised. A laser can easily damage the human eye. The patient, dentist, and assistant should always wear protective eyewear. There are inserts available for dentists who wear surgical telescopes. It is recommended that the use of oxygen and nitrous oxide/oxygen should be turned off when using a laser.

Nd:YAG, Diode lasers, and CO2 are primarily used on soft tissue. These lasers provide good coagulation. The laser energy of the Diode and Nd:YAG can penetrate a few millimeters into the tissue. A CO2 laser penetrates less than a millimeter and can produce excellent coagulation along with a very precise cut. Erbium wavelength lasers can cut tooth, bone, and soft tissue. Erbium lasers have an affinity for water. Erbium lasers are not good at providing hemostasis but are kind to tissue, as they only penetrate microns into tissue.

The first question that a dentist needs to ask before buying a laser is: What do I want the laser for? Then ask: Will I use it exclusively for soft-tissue work? Do I have the room for a large erbium laser box in my operatory? Do I want to prep teeth and bone? Your choice of a laser will be dictated by the answers to these questions. The goal is to choose the correct laser and wavelength for the procedure you want to accomplish.

Laser procedures are usually divided into hard and soft tissue. Soft-tissue laser procedures are for periodontal treatment. Oral surgery, such as biopsies and frenectomies, can be accomplished with all soft-tissue lasers.

Now you need to choose the soft-tissue laser with the proper wavelength. If you want a laser for soft-tissue periodontal procedures, I would recommend an Nd:YAG as there is lots of supportive literature. Other procedures can be accomplished with either Nd:YAG, CO2, or Diode lasers. Soft-tissue lasers offer better visualization of the surgical field, because they cut and seal at the same time.

Periodontal procedures such as the laser-assisted new attachment procedure (LANAP) allow for minimally invasive surgery as an alternative to conventional flap surgery. The laser is placed into the periodontal sulcus and removes the diseased epithelium. Scaling is performed to remove calcified plaque and calculus from the root surfaces. The Nd:YAG produces a bactericidal effect in the pocket. Some individuals have had regeneration of cementum, bone, and periodontal ligament while reducing pocket depth.

Nd:YAG, Diode, CO2, or Er:YAG lasers can also be used for the destruction of aphthous ulcers. A laser can transform a sore that hurts into a sore that does not hurt, with more rapid healing. Advantages of soft-tissue lasers may include minimal postoperative pain, minimally invasive surgeries, and in many cases, the elimination of sutures. Second-stage implant surgery can be safely accomplished with Diode, Erbium, and CO2 lasers.

The KaVo DIAGNOdent uses a laser to help identify caries. Diagnostic lasers can be used to detect smooth surface, interproximal, and pit and fissure caries. These lasers operate at a wavelength of 655nm and are red in color. At this wavelength healthy enamel and dentin have little or no fluorescence. The laser light causes the carious areas of the tooth to fluoresce. The fluorescence is then measured, and the determination of caries can be made. Laser caries detection offers greater sensitivity than conventional visual and tactile methods. Early diagnosis of carious lesions makes minimally invasive dentistry possible.

Erbium-based lasers (Er:YAG and Er,Cr:YSGG) can do both hard- and soft-tissue procedures. Many general dentists are looking to lasers to prepare teeth for restorations. Erbium lasers are effective for caries removal and cavity preparation. Many procedures can be done with an Erbium laser without anesthesia, and these lasers make treating pediatric patients easier. Erbium lasers do not cut teeth as fast as a high-speed handpiece, but they are much more conservative when preparing teeth. Erbium lasers can be used to remove composites but not amalgam restorations. Soft-tissue procedures with an Erbium laser can produce more bleeding compared to soft-tissue-only lasers.

The major objections most dentists have to lasers are cost and limited procedures. Lasers are perfect for minimally invasive dentistry. The more healthy tooth structure conserved during a procedure, the better the long-term health of the tooth. A laser may never replace a high-speed handpiece, but it is another tool to better assist the dentist.

Dentists need to become knowledgeable in the use of lasers so they can maximize the number of procedures that a laser can accomplish. As for cost issues, some soft-tissue lasers are available for less than $3,000, so a laser can be within reach of every dental office. It is just a matter of dentists deciding to educate themselves on the benefits of lasers.


( By Martin Jablow DMD, FAGD )


Source: (http://www.dentistryiq.com/articles/2010/04/laser-technology-overview-for-general-dentists.html)

Wavelength

 In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats, and thus the inverse of the spatial frequency. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings and is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. Wavelength is commonly designated by the Greek letter lambda (λ). The concept can also be applied to periodic waves of non-sinusoidal shape. The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopesof modulated waves or waves formed by interference of several sinusoids. Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths. Wavelength depends on the medium (for example, vacuum, air, or water) that a wave travels through.Examples of wave-like phenomena are sound waves, light, water waves and periodic electrical signals in a conductor. A sound wave is a variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary. Water waves are variations in the height of a body of water. In a crystal lattice vibration, atomic positions vary.Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in sinusoidal waves over deep water a particle near the water's surface moves in a circle of the same diameter as the wave height, unrelated to wavelength. The range of wavelengths or frequencies for wave phenomena is called a spectrum. The name originated with the visible light spectrum but now can be applied to the entire electromagnetic spectrum as well as to a sound spectrum or vibration spectrum. 

Laser diode

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 Dental diode lasers, sometimes called soft-tissue lasers, are ideal for procedures that involve cutting or contouring oral soft tissues. 

Carbon dioxide laser

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 The carbon dioxide laser has been used for soft tissue surgery in modern dentistry, advanced dentistry and cosmetic dentistry. 


Nd:YAG laser

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 The Nd:YAG laser has both soft and hard tissue applications.  

Er,Cr:YSGG laser and Er:YAG laser

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 Erbium lasers (Er,Cr:YSGG and Er:YAG) interact with the water of soft and hard tissue. 

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Biological Dentistry and the Science of WaterLase

  Our Biological Dentistry™ approach to diagnosis, treatment and prevention is the logical result of our investigations into why conventional treatment with the drill causes pain, necessitates the use of anesthetic, and causes unintended damage to surrounding healthy tissue – negative consequences that have long been accepted for lack of a better solution. A fresh look at the anatomy and physiology of teeth and oral soft tissues showed us there could be a more biologically friendly way to treat them.Tooth enamel naturally contains up to 5% water; dentin and bone up to 25%. Years of BIOLASE research led to discovery of a water-energizing 2,780 nm YSGG laser and a handpiece that delivers air and water in precise proportions – both BIOLASE patented – that combine to symbiotically excite water molecules from both the handpiece spray and inside the target tissue. The result is an effective biological micro-ablation of tooth structure. The atomized spray of water and air continually re-hydrates the tooth, preventing heat and pain. We named this technology WaterLase©.  

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Why WaterLase YSGG Laser Energy is Superior to Erbium YAG

  A graph of the absorption of various wavelengths of laser energy in water shows that erbium laser energy is absorbed at a rate 300% greater than YSSG laser energy. On hard tissue, an erbium laser will quickly vaporize the water naturally present in dentinal tubules and enamel prisms and damage the tooth, without the use a far greater amount of water spray than the YSGG laser. This additional water at the tissue surface means less energy is being absorbed by the hydroxyapatite and enamel, significantly reducing the cutting speed of the erbium laser. On soft tissue, the erbium laser's higher absorption by water means that it draws more blood and fluid to the surface, dehydrating the tissue and obscuring the field of view. The physics of the YSGG wavelength is perfectly balanced to remove enamel and dentin, and to surgically cut and coagulate soft tissue. 

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Fotona

 Fotona's dental lasers are the ideal tools for all soft-tissue treatments. Unlike conventional oral surgery techniques, dental lasers allow soft-tissue treatments without the need for a scalpel or sutures. Surgical procedures are precise, bloodless and pain-free thanks to the simultaneous coagulation effect that occurs during laser-tissue interaction.  

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Low Level Laser Treatment

 Laser therapy is not a foreign concept to most dental practitioners as many practitioners include surgical lasers in their arsenal of high-tech equipment. Low-level lasers are a subset of the laser family that elicits a cellular response from the cell, as opposed to a photothermal effect, resulting in improved healing, pain reduction and a reduction in inflammation. Low-level lasers frequently use similar wavelengths to surgical lasers; however, use a significantly reduced power and a larger tip diameter.  

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Current and future trends in laser medicine.

 In this overview, a number of the major current, and possible future developments in laser medicine are explored. In therapeutic applications, particular emphasis is given to obtaining selectivity in tissue targets and interaction mechanisms in order to achieve specific biological effects. This includes spatial confinement of thermal damage by pulsed laser irradiation and targetting by exogenous photothermal or photochemical chromophores. The potential for diagnostic applications of lasers in medicine is illustrated primarily by various in vivo spectroscopic techniques. Both therapeutic and diagnostic applications will rely increasingly on the development of total systems in which lasers will form only one, albeit an essential, part. Numerous scientific and technical problems need to be solved in order to realize the full clinical potential of the many new concepts in laser medicine. The impetus for such progress will come from integrated, multidisciplinary collaborations between medical, scientific and industrial groups. 

What is amalgam?

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 Amalgam is a combination of metals that has been the most popular and effective filling material used in dentistry for the last 150 years. Although it sometimes is called "silver amalgam," amalgam actually consists of a combination of metals. These include silver, mercury, tin and copper. Small amounts of zinc, indium or palladium also may be used.Tooth-colored materials now can be used to restore teeth. Therefore, amalgam is used less often than in the past. However, the newer materials can't be used for all situations. Amalgam is less costly than other materials. It also holds up better over time, especially in teeth that undergo a lot of pressure and wear from chewing.  

Why the concern about mercury in amalgam?

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 Mercury is a metal that occurs naturally in the environment. Mercury can exist as a liquid, as in many thermometers. When heated, it becomes a gas. It also can be combined with many other materials.Everyone is exposed to mercury through air, drinking water, soil and food. Concerns have been raised, for instance, about the amount of mercury building up in fish as a result of pollution. Mercury enters the air from industries that burn mercury-containing fuels. Mercury from all sources can build up in body organs.As with most substances, the degree of harm caused by mercury in the body is related to the amount. Very low levels don't cause any ill effects. At higher levels — for instance, when workers are exposed to mercury through their jobs — mercury can cause several symptoms. These include anxiety, irritability, memory loss, headaches and fatigue.The controversy over amalgam centers on how much mercury fillings released and how much the body absorbs. In the past, amalgam fillings were thought to be inert. This would mean that no mercury was released once the filling was placed in the tooth. In recent years, sophisticated tests have changed this view. Very small amounts of mercury in the form of vapor can be released as the amalgam filling wears.Research on this issue is complex and has arrived at various estimates of the actual amount of mercury released. However, several reviews of the research have concluded that any amount released from amalgam in the mouth is very low.Studies have shown that the amount of mercury you are exposed to from your fillings is less than the amount that most people are exposed to in their daily environment or in the food they eat.  

Should pregnant women be concerned about amalgam fillings?

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 Research has not shown any health effects from amalgam fillings in pregnant women. However, mercury can cross the placenta. In general, dentists advise pregnant women to avoid unnecessary dental care. Women should not get amalgam fillings during pregnancy. Dentists can suggest other materials for any pregnant woman who needs a cavity filled.  

How safe is amalgam?

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 Millions of people have amalgam fillings. Concern has been raised over the mercury in amalgam.Many studies on the safety of amalgam fillings have been done. In 2009, the U.S. Food and Drug Administration (FDA) evaluated this research. It found no reason to limit the use of amalgam. The FDA concluded that amalgam fillings are safe for adults and children ages 6 and above.However, some groups asked the FDA to reconsider. That review is under way.  

If amalgam is safe, why does my dentist take precautions when handling it?

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 Because dentists work with mercury almost every day, they must take safety precautions. Without protection, dentists can inhale mercury vapors. Over time, this exposure can produce symptoms of mercury toxicity.To make dental amalgam, dentists mix liquid mercury with a powder containing silver, tin and other metals. Dentists buy special capsules that contain the powder and the liquid mercury, separated by a membrane. They use special machinery to puncture the membrane and mix the amalgam while it is still in the capsule. Once mixing is complete, the capsule is opened. By the time the amalgam is placed in your tooth, the mercury has formed a compound with the other metals. It is no longer toxic.If you are getting an amalgam filling or having one removed, your dentist will use high-powered suction to remove any excess amalgam from your mouth. Dentists' offices have special disposal systems for any extra amalgam. Special traps in the sink drains and in the suction tubes prevent amalgam from entering the plumbing system.  

Are there alternatives to amalgam?

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 There is now a dental amalgam that contains indium as well as mercury. The indium helps retain the mercury so that less is released into the environment. There are also high-copper amalgams. They contain less mercury and more copper.Dentists use other materials to restore teeth. These include composite resin, porcelain and gold. Amalgam is stronger than composite resin and requires less time in the dentist's chair. Composite resin is a tooth-colored material. Because it wears faster than amalgam, composite resin can't be used in every situation.  

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