Light tooth seal: the good, the difference from the usual

Modern dentistry is progressing at an incredible rate. Rapid development makes it increasingly possible to introduce new tools, medicines and filling materials into this sphere. One of the most perfect materials for sealing today is the photopolymer composite, of which the so-called light seal is composed.

Many people are interested in the question, what is the name of a light seal in dental practice? There may be several answers: photopolymer, photocomposite, a light-curing composite seal, a light-cure seal. All these names are correct and widely used in dentistry. You should only choose the term that is best remembered. The material of the light seal (photopolymer composite) consists of an organic matrix (monomer), an inorganic filler and a polymerization activator. In addition to the basic elements, the composition of the composite includes various dyes, fillers, stabilizers and pigments. The material is produced in special syringes, where the composite is in a plastic state. In order for the photopolymer to harden, it is necessary to use a special lamp. This device is a source of blue light, ultraviolet and infrared radiation. Light wavelength of about 760 nm activates the polymerization reaction and monomers (organic matrix) are joined by a chain. Thus, the lamp for the light seal is the starting mechanism of solidification.

The advantages of light seals in front of other restorative materials encourage dentists to use a photopolymer composite every day. This material has an ideal consistency: it does not spread and at the same time is not excessively viscous. With its help it is very convenient to simulate fissures, tubercles, cutting edge and other surfaces of the teeth. By the way, in the sets of many manufacturers there is a special fluid-filled composite. It has an oily consistency and is ideal for filling very small cavities.

The next and important advantage is the control of solidification of the material. Until the dentist begins to photopolymerize using a lamp, the seal will remain in a soft state. This allows you to carefully and accurately form all the anatomical surfaces of the tooth without haste. The possibility of layer-by-layer restoration is another advantage of photocomposites. It is much easier for a dentist to make material parts, to restore each tooth surface separately. This allows you to concentrate on the details and perform work qualitatively. Moreover, layer-by-layer application of folopolymer makes it possible to select a shade for a certain portion of material at each stage. This approach ensures high aesthetic properties of the future restoration. After all, the solid tissues of our teeth have a different color and degree of transparency. Therefore, the seal should reproduce the optical characteristics of enamel, dentin and cement. The composite material perfectly copes with this task.

One of the most important properties of the sealing material is tensile and compressive strength. Since the teeth take on a large chewing load, all of its tissues must withstand the pressure on them. This requirement also applies to seals that mimic certain surfaces of the teeth. Composite materials due to inorganic filler have very high strength characteristics. Thanks to this, the longevity of the restoration rises many times. As a consequence, doctors more safely take on the warranty, and patients are less likely to face problems such as a dropped seal, a split of the composite restoration and the mobility of the seal.

With regard to contact with liquids and moisture, the photopolymers exhibit different properties in the plastic and hardened state. When a seal is only inserted into the tooth cavity, any contact with the liquid can disrupt the further polymerization process. If, in the process of restoration, the tooth was isolated from the saliva, the prognosis for the filling is favorable. The cured composite perfectly tolerates the presence in a humid environment and does not dissolve in the oral fluid.

Absolutely all the filling materials have a certain degree of shrinkage. Unfortunately, the photopolymer composite is no exception. He, as well as all the cements and amalgams, decreases in size after solidification. However, light seals still have some advantage over other materials. The matter is that photopolymer composites are introduced in small portions. After each addition, the material is illuminated with a lamp, which leads to its solidification. Thus, the introduction of the next batch of material makes it possible to compensate for the shrinkage of the previous dose. This minimizes the shrinkage factor and ensures a long service life of the seal.

The next advantage of light seals is the chemical fixation of the filling in the cavity of the tooth. To achieve this effect, treatment should be supplemented by several stages. The first stage - etching - is a procedure that allows you to clean the surface of the tooth and prepare it for sealing. The second stage is the application of an adhesive system, which is the link between the filling and the tooth (the so-called adhesive for the seal). If these manipulations are carried out correctly, then after the filling, the seal is securely fixed in the cavity and will last for many years.

Modern dentistry is distinguished by the fact that dentists try to keep as many healthy tooth tissues as possible. However, working with some filling materials, such a philosophy is very difficult to adhere to. The thing is that many fillings must have a certain shape (box-shaped, trapezoidal, oval, etc.), this is due to their physical properties. As a result, the formation of the right cavity causes the dentist to remove the healthy dentin and enamel in order to achieve the correct geometry. Although this is acceptable in modern dentistry, it is extremely undesirable. After all, hard tissues are very valuable for the further functioning of the tooth. Moreover, scientists have not yet invented a material that could be compared in biophysical properties with a real tooth and replace it even partially. Working with a photopolymer composite, there is no need to form a cavity of a certain shape and size. It can seal both micro-cavities and restore up to 50% of the chewing surface of the tooth.

The material of the light seal is considered to be one of the most biosomitable in dentistry. The photopolymer composite has no toxic effect on the pulp tissue. After a thorough grinding and polishing, the seal becomes perfectly smooth. This excludes possible mechanical damage to the oral mucosa. The chemical composition of the composite also provides a low degree of allergic and toxic effects on the mucosa.

Types of light seals

High competition in the market of dental products forces manufacturers to produce more and more advanced versions of filling materials. In this regard, the light seal can be divided by the concentration of the filler, the dispersion of solid particles, the color characteristics and the manufacturer. Also it is necessary to allocate a special material - a compomer, which represents a combination of glass-ionomer cement with a composite and is light-cured. Moreover, some glass ionomer cements are also polymerized by a lamp. Therefore, purely theoretically, compomers and glass-ionomer cements have every right to be called a light seal. However, the popularity of the use of these materials is lower than that of composites. Therefore, in society, the terms light and photopolymer seal meant composite restoration.

As stated earlier, photopolymer composites are the most universal filling materials for today. Their advantage is determined not only by the kind of polymerization and convenience of work, but also by a large number of diverse species. It is worth mentioning that when performing restoration of one tooth a doctor can use about five varieties of the same material. Composites are divided into micro-filled, mini-filled, macro-filled and hybrid. All these names speak only of the number and size of the solid particles that are dissolved in the organic resins of the composite.

Microfilled - the most finely dispersed composites, they contain 37% filler with a particle size of 0.01-0.4 μm. Such a composition makes it possible to carefully polish and polish the seal. As a result, the restoration will get a very smooth and shiny surface that will reproduce the optical properties of the tooth. Due to the small amount of solid filler, the seal will not be distinguished by high strength. Therefore, the indications for the use of this material are mainly carious and non-carious teeth defects that require aesthetic restoration and are not designed to perceive a high masticatory load (cervical region and contact surfaces of the teeth). Examples of microfilled composites are Filtek A-110 and Silux Plus (3M ESPE, USA), Heliomolar (Ivoclar Vivadent, Liechtenstein).

Mini-filled composites occupy an intermediate position between micro-filled and macro-filled. The particle size of these materials is 1-5 μm. The content of the filler is 50-55%. On the one hand, such a composition is the golden mean compared with coarse-dispersed and finely dispersed composites. However, grinding and polishing of fillings from mini-filled materials does not allow achieving optimal results, and their strength is not high enough. Therefore, these materials are rarely used today, and manufacturers produce them in very small quantities. An example of a light curing composite is Marathon V (Den-Mat, USA).

MacPronapolized photopolymers - composites with a particle size of up to 12-20 microns and their content up to 70-78% of the total volume of the material. A large amount of coarse filler improves the strength of the filling tens of times compared to micro- and mini-filled materials. This allows the composite to be used to restore the chewing and lateral surfaces of the teeth. However, despite the powerful advantage of such seals, high abrasiveness makes it impossible to achieve a smooth surface even after a long grinding and polishing. As a result, the aesthetics of such a seal leaves much to be desired. An example of a macrophilic light composite is Folacor-C (Rainbow, Russia).

Hybrid photopolymers are by far the most popular composites. They contain in their composition a filler with macro-, mini- and microparticles. From the total volume of material, the solid filler occupies up to 70-80%. This combination of a multitude of particles of different sizes makes it possible to preserve the high strength of the seal and, during polishing, achieve an ideal aesthetic of restoration. It can be said that hybrid composites combined the positive qualities of macrophilic and microphilic photopolymers. If the first experiments with hybrid composites did not cause significant resonance and popularity, the further evolution of the material proved its undeniable advantage.

Totally made composites are a kind of hybrid composites in which the number of particles of different dispersity is accurately calculated and the optimum ratio is found. This significantly increased the physical and chemical properties of the material, which made it one of the most popular means for restoration of teeth. Many of them have been successfully produced and used so far: Spectrum THP (Dentsply), Valux Plus, Filtek Z250 (3M ESPE), Charisma (Heraeus Kulcer). However, on this the way of modernization of totally executed composites did not end. The next stage of evolution was the discovery of micro-matrix composites. This group of materials is characterized by the fact that during manufacturing all the filler particles are pretreated by a special technique. This allows to reduce the dispersion of the filler without loss of strength of the composite. Examples of this type of materials are: Point 4 (Kerr), Esthet X (Dentsply), Vitalescens (Ultradent).

Nanocomposites are a subspecies of hybrid composites that contain very small particles of inorganic filler. The size of the elements is about 0.001 μm. A large number of microparticles can improve the aesthetic properties of the material without reducing the strength of the seal. One of the first nanocomposites was the photopolymer "Esthet X" from the company Dentsply.

Liquid flow is a special group of composite materials that combines the properties of mini-filled (dispersed filler - 1-1.6 microns), microfilled (the number of inorganic elements is 37-47%) and hybrid (accurate calibration and filler processing) composites. These composites are used for filling small cavities and fissures. Liquid-flowing materials have a physical property, which is called thixotropy. This means that the material in the liquid state is able to maintain its shape until it is not mechanically affected. That is, the material begins to spread only when the dentist touches the instrument with it. One of the popular liquid-flow composites is Latelyux flow (Latus, Ukraine), Filtek flow (3M ESPE, USA).

In addition to the various options in the composition of composites, they are subdivided in colors and shades. The need for such a classification is due to the fact that the tooth tissues (enamel and dentin) have different degrees of opacity (opacity, opacity). Moreover, each person's teeth have an individual shade, which requires careful selection and combination of different types of composite. It is also worth adding that with age, the color of the teeth is changing. For example, in young people teeth have a low-saturation color and high opacity (haze). In adults and the elderly - on the contrary, teeth are brighter and more saturated, but at the same time more transparent. Proceeding from these rules, the manufacturers of dental materials set a goal - to create the most universal set with a minimum number of syringes of the composite. For example, GC (Japan) produces Essentia, in which there are only 7 shades and 4 modifiers (dye). By the way, if you count all the shades of teeth on the Vita scale, then they will be 16. However, GC focused not on the shades of teeth in general, but on the color characteristics of dentin and enamel. The creators of Essentia argue that the ability to correctly combine the different shades of hard tissue of the teeth allows you to reproduce any color of the light seal. For comparison, the company Heraeus Kulzer (Germany) went the other way. Their universal set Charisma contains three types of composites for dentin of different opacity. Also there are 11 most common shades of enamel, which correspond to the Vita scale. Moreover, there are 7 additional shades in the set. Total, the dentist owns a palette of 23 variants of the composite. However, despite the different approach of manufacturers, it is impossible to say exactly which light seal is better. The fact is that the companies GC and Heraeus Kulzer produce high-quality products and have an equally high level of authority. Therefore, the types and names of light seals are not as important as the ability to work with a certain set of composites.

Which is better: a light seal, a chemical seal or a cement seal?

Many people ask themselves: what is the difference between a light seal and an ordinary one? Which is preferable: a cement or light seal? It should be immediately said that there is no absolute favorite. Each material has certain advantages. Therefore, we will compare glass-ionomer cements and composites (photopolymer and chemical) by several criteria. The first factor is strength. Dental cement in its structure is less durable than composites. If we compare the composites of chemical and light polymerization, then light composites are more durable due to their full hardening. The fact is that photopolymers are introduced into the cavity of the tooth in small portions. This allows you to carefully perform "flash" at each stage. Chemical composites are kneaded and introduced in one portion. As a rule, even after careful mixing in the seal, a certain amount of monomer remains, which reduces the strength of the filling. Therefore, in this category, a composite of light curing composite achieves a deserved victory.

The second factor is resistance to humid environments. All dental materials better retain their properties in a dry environment. However, moisture is present all the time in the mouth. Therefore, manufacturers are trying to create a material that will be as stable as possible to contact with oral fluid. Among the listed materials, glass ionomer cements have the highest moisture resistance. They are indicated for sealing cavities in the gum region, where the tooth is in contact with the liquid continuously. Composites, although they have a certain level of resistance, but it is less pronounced than in the SIC.

The third factor is biocompatibility. In this category, glass-ionomer cement also exceeds composites. This is due to the fact that the photopolymers solidify with a special lamp, which is the source of ultraviolet and infrared waves. They are able to heat the pulp (nerve) to a temperature of 70-80 °, which can cause aseptic (non-infectious) pulpitis. As for chemical composites, it was already mentioned earlier that after solidification, a certain amount of monomer remains in them, which has a toxic effect on the structures of the tooth and oral cavity.

The fourth factor is aesthetics. Only photopolymer composite can boast a rich spectrum of all kinds of colors and colors. Multistage material application allows layered reproduction of all hard tooth tissues and achieve maximum aesthetics. Unfortunately, chemical composites and SIC are less aesthetic. Although there are special "aesthetic" glass ionomers, it is not so convenient to work with them as with photopolymers.

The fifth factor is the cost. Generally speaking, the fillings of glass-ionomer cement are about 3-5 times cheaper than composite restorations. But this does not mean that it is more profitable to put them than the fillings from the photopolymer. In fact, it was already mentioned earlier that the composite is more durable than cement.

The sixth factor is the convenience of work. It is much more convenient to use the material that does not put the specialist in a "narrow framework". For example, in chemical composites and SIC, after solidification, the solidification process is activated. Therefore, the dentist has to adjust for time constraints. When staging a light seal, a specialist has the opportunity to work with the material until he successfully simulates the desired surface of the tooth. Also, when working with photopolymers there is no mixing process, which also frees the dentist from additional work. Finally, the layered insertion of the material allows the restoration process to be divided into many small steps, which simplifies the work of the restorer.

Based on the comparative characteristics, it can be concluded that there is no ideal material. For composites and for cements, there are separate indications. If you choose, a chemical seal or light, then the choice is obvious - a light seal is now more relevant.

Indications

Photopolymer composite is the most universal filling material. Therefore, it has the largest list of indications for use. A light seal can be installed after treatment of carious and non-carious (erosion, wedge-shaped defect, fluorosis, necrosis of enamel, etc.) lesions. Also photopolymers are used in the final stages of treatment of pulpitis and periodontitis. With tooth injuries (fractures, cleavages of the enamel) with the light-curing composite, an aesthetic restoration can be carried out. If a person has abnormal abrasion, but there is no possibility for immediate prosthetics, a light seal can be used to temporarily restore the eroded mounds. Before prosthetics non-removable structures (crowns, bridges), the tooth tooth is shaped and sized. In order to give it the necessary outlines, it is possible to use a composite of light polymerization. Since this material has a wide range of different shades and a high level of strength, it can be used both for the restoration of chewing teeth and for aesthetic restorations of incisors, canines and premolars (small molars).

Preparation and technique of installing a light seal

Restoration of teeth with a photopolymer composite is a multi-stage and complex process that requires concentration and responsibility from the dentist. Preparing the tooth for sealing involves the removal of the affected tissue and the proper formation of the cavity. Do not leave softened dentin and enamel in the tooth, because they can lead to a rapid loss of the seal and various complications. The cavity of the tooth should be formed in such a way that the restoration has a sufficient area of support. This factor is especially important in those cases when a light seal is placed on the front teeth. Unlike barrel and cylindrical chewing, incisors and canines have a more elongated shape. Consequently, their restoration is complex and requires the creation of retention points (additional pads). Therefore, during the formation of the cavity, various steps are created. If the degree of destruction of the tooth is too large, then the nerve is removed, a pin is inserted into the channel and a constant light seal is then established.

Before installing the seal, the tooth cavity is susceptible to acid etching. This is the so-called cleaning of the walls of the cavity from sawdust and other foreign elements. Moreover, by etching the enamel, dentinal tubules are opened, which are one of the factors of fixing the seal. The next step is applying an adhesive system that acts as a link between the filling and the tooth. The quality of the adhesive system is no less important than the quality of the composite itself, because this affects the life of the light seal. After the adhesive has been exposed, the final stage is coming - the restoration itself, which involves the insertion of a filling material into the tooth cavity. As previously mentioned, the composite is introduced in small portions, which are roughly equal in volume to the grain of rice. Each serving is carefully pressed against the walls and bottom of the cavity, after which it is lighted. This stage is repeated until the entire tooth is restored. When the simulation of all surfaces is complete, the finishing step is reached. It is necessary not only to create a brilliant "enamel", but also to prevent the settling of various substances on the surface of the restoration. For grinding and polishing, special disks, polishes, brushes and pastes are used. For the treatment of contact surfaces, discs and abrasive tapes-strips are used.

A light seal on dairy and unformed permanent teeth (up to 12-13 years old) is undesirable. This is due to the fact that in such teeth the dentinal tubules are very wide. Elements of the composite can get too deep into the channels, penetrate them into the pulp and cause pulpitis. The same applies to etching hard tooth tissues, which are performed with orthophosphoric acid. Cases of pulpitis do not occur very often, but the likelihood of such treatment outcome is present. It is also worth mentioning that setting a light seal for children is not an easy task for a doctor, a child and his parents. Restoration by composite is a long and multi-stage process. Not every child has patience and emotional balance in order to transfer this procedure. Therefore, it is much more expedient in this case to use glass-ionomer cement. To work with him, it is not necessary to drill a tooth and perform a dressing. Moreover, the material is introduced in one portion, which reduces the amount of manipulation in the patient's mouth.

Indications for filling with photopolymer composites in pregnant women do not differ from the indications for restoration of teeth in other people. Moreover, treatment of "live" teeth is recommended under local anesthesia. After a sudden and sudden pain can cause a pregnant woman more harm than a few milliliters of anesthetic. The same goes for the photopolymer lamp, which does not adversely affect the fetus. Therefore, a light seal pregnant can be installed at any time.

Photopolymer composites do not require special conditions, expensive equipment to work with them. A light seal can be installed in the state polyclinic or a private dental office. The result of treatment depends only on the quality of the material and skills of the doctor.

Contraindications to installation

Contraindications for setting a light seal primarily relate to the use of an etchant and a photopolymer lamp. Regarding orthophosphoric acid, it has already been mentioned earlier that in milk teeth and unformed permanent etching gel, it can have a toxic effect on pulp tissues. Restoration with a light bulb is not recommended for people with pacemakers or pathologies of the eyes. Other contraindications relate not only to photopolymers, but also other filling materials. It is a question of those clinical cases in which filling is inadmissible. For example, the tooth crown is destroyed by 90%, but a person wishes to restore it with a composite. In this case, the seal is doomed to fall out, and the tooth - to re-treatment. Also, one of the contraindications for permanent sealing is restoration with incomplete treatment of periodontitis. Many people can not long tolerate the lack of aesthetics of a smile. Therefore, they often ask to complete the treatment of periodontal disease and perform a permanent restoration. If the doctor does so, after a few months the tooth may be removed.

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Consequences and complications

The wide application of photopolymer composites guarantees the occurrence of various consequences and complications in some dentists after treatment. This is due to a number of factors. First, popular, high-quality products provoke the appearance of a large number of counterfeits on the market. As a result, the use of non-original materials leads to the fact that the restoration is carried out in good faith, but a month later the person returns to the dentist and complains that the light seal has cracked, fell out or darkened. Also, these phenomena can be associated with a violation of the restoration protocol. Wrong application of the adhesive system, poor isolation of the tooth from saliva, overestimation of the restoration contribute to the rapid loss of the seal. One of the most common symptoms after filling is pain in the tooth. Often people ask themselves the question: "What if you put a light seal, and the tooth still hurts?". For medical protocols, the next 2 weeks should be monitored for the dynamics of pain. If the symptomatology decreases, the cause may be the hypersensitivity of the tooth to the composite. This condition does not require treatment and passes by itself. If the light seal hurts acutely, then this can talk about the development of pulpitis. In this case, you need to contact your doctor to find out the cause of the inflammation.

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Care and advice after installing a light seal

The first question that arises after treatment: through how much you can eat after installing a light seal? As a rule, it is necessary to refrain from eating for the next two hours from the moment of restoration. However, there is one nuance: on the day of filling it is necessary to exclude the use of coloring products (beets, black tea, coffee, chocolate, etc.). Such food colors light fillings, thus reducing its aesthetic performance. Many people ask the question: "Does the beer color a light seal?" The answer will depend on the frequency of consumption and the type of beer. If the beer is dark, then it can affect the shade of the seal with frequent use. You can get the same answer to the question: "Is it possible to smoke after installing a light seal?" In case the filling has changed its color, it is worthwhile to understand the reasons for the pigmentation. After all, one of them is the development of secondary caries, the treatment of which will require removal of the light seal. If less than a year has passed from the moment of filling, most likely the replacement of the light seal will be made under warranty. If the state of restoration is satisfactory, but a person smokes, drinks a lot of coffee and tea, then the opacity of the top layer of the seal may have occurred. In this case, the restoration of the light seal is recommended. At the same time, the upper sphere of the filling is ground, a thin layer of "fresh" composite is applied to it. Also in the dental office you can whiten the light seal. For this, various air blasting machines (Air flow), grinding nozzles, polishes, brushes, pastes, etc. Are used. With their help, you can remove the surface microlayer of the seal, which has accumulated pigments from food and cigarettes.

Patients' feedback confirms the quality and reliability of photopolymer restorations. Especially positively people speak about aesthetic restorations on the frontal teeth. After all, such light seals can improve the quality of life and improve self-esteem. As for the durability of composite fillings, everything is simple: if you regularly visit a dentist, follow the rules of oral hygiene, avoid heavy loads on teeth and lead a healthy lifestyle, the life of a light seal can last for tens of years.