Light dental filling: what is good, difference from the usual one

Modern dentistry is progressing at an incredible speed. Rapid development allows for the introduction of new instruments, medicines and filling materials into this area more and more often. One of the most advanced filling materials today is a photopolymer composite, which is what is known as a light filling.

Many people are interested in the question of what a light filling is called in dental practice. There may be several answers: photopolymer, photocomposite, filling made of light-curing composite, light-curing filling. All these names are correct and are widely used in dentistry. You just need to choose the term that is best remembered. The material of the light filling (photopolymer composite) consists of an organic matrix (monomer), an inorganic filler and a polymerization activator. In addition to the main elements, the composite contains 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 with a wavelength of about 760 nm activates the polymerization reaction and the monomers (organic matrix) are connected in a chain. Thus, the lamp for the light filling is the trigger for hardening.

The advantages of light fillings over other filling materials encourage dentists to use photopolymer composite every day. This material has an ideal consistency: it does not flow and at the same time is not excessively viscous. It is very convenient to use it to model fissures, tubercles, cutting edges and other surfaces of teeth. By the way, many manufacturers have a special flowable composite in their kits. It has an oily consistency and is ideal for filling very small cavities.

The next and no less important advantage is the control of the material hardening. Until the dentist starts photopolymerization with a lamp, the filling will remain soft. This allows for careful and precise formation of all anatomical surfaces of the tooth without haste. The possibility of layer-by-layer restoration is another advantage of photocomposites. It is much easier for the dentist to apply the material in parts, restore each tooth surface separately. This allows concentrating on details and doing the job well. Moreover, layer-by-layer application of the folopolymer makes it possible to choose the shade for a certain portion of the material at each stage. This approach ensures high aesthetic properties of the future restoration. After all, the hard tissues of our teeth have different colors and degrees of transparency. Therefore, the filling must reproduce the optical characteristics of enamel, dentin and cement. Composite material copes with this task perfectly.

One of the most important properties of a filling material is its tensile and compressive strength. Since teeth bear a large chewing load, all of its tissues must withstand the pressure on them. This requirement also applies to fillings that imitate certain tooth surfaces. Composite materials, due to the inorganic filler, have very high strength indicators. Due to this, the durability of the restoration increases several times. As a result, doctors are more confident in taking on warranty obligations, and patients are less likely to encounter problems such as a fallen filling, chipped composite restoration, and filling mobility.

As for contact with liquids and moisture, photopolymers exhibit different properties in the plastic and hardened state. When the filling is just inserted into the tooth cavity, any contact with liquid can disrupt the further polymerization process. If the tooth was carefully isolated from saliva during the restoration process, the prognosis for the filling is favorable. The hardened composite tolerates being in a humid environment well and does not dissolve in oral fluid.

Absolutely all filling materials have a certain degree of shrinkage. Unfortunately, photopolymer composite is no exception. It, like all cements and amalgams, decreases in size after hardening. However, light-curing fillings still have a certain advantage over other materials. The fact is that photopolymer composites are introduced in small portions. After each introduction, the material is illuminated with a lamp, which leads to its hardening. Thus, the introduction of the next batch of material allows you to compensate for the shrinkage of the previous dose. This minimizes the shrinkage coefficient and ensures a long service life of the filling.

The next advantage of light-cured fillings is the chemical fixation of the filling in the tooth cavity. To achieve this effect, the treatment must be supplemented with several stages. The first stage is etching - a procedure that allows you to clean the tooth surface and prepare it for filling. The second stage is the application of an adhesive system, which is a connecting element between the filling and the tooth (the so-called filling glue). If these manipulations are performed correctly, then after exposure to light, the filling will be securely fixed in the cavity and will last for many years.

Modern dentistry is distinguished by the fact that dentists try to preserve as much healthy tooth tissue as possible. However, when 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 correct cavity forces the dentist to remove healthy dentin and enamel to achieve the correct geometry. Although this is acceptable in modern dentistry, it is highly 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 compare with a real tooth in biophysical properties and replace it even partially. When working with a photopolymer composite, there is no need to form a cavity of a certain shape and size. It can hermetically seal both microcavities and restore up to 50% of the chewing surface of the tooth.

The material of the light filling is considered one of the most biocompatible in dentistry. The photopolymer composite does not have a toxic effect on the pulp tissue. After careful grinding and polishing, the filling becomes perfectly smooth. This eliminates possible mechanical damage to the oral mucosa. The chemical composition of the composite also ensures a low degree of allergic and toxic effects on the mucosa.

Types of light seals

High competition in the dental market forces manufacturers to produce new and more advanced versions of filling materials. In this regard, light-curing fillings can be divided by filler concentration, dispersion of solid particles, color characteristics and manufacturer. It is also worth highlighting a special material - compomer, which is a combination of glass ionomer cement with a composite and is light-curing. Moreover, some glass ionomer cements are also polymerized with a lamp. Therefore, purely theoretically, compomers and glass ionomer cements have every right to be called light-curing fillings. However, the popularity of using these materials is lower than that of composites. Therefore, in society, the terms light and photopolymer fillings began to imply composite restoration.

As stated earlier, photopolymer composites are the most versatile filling materials today. Their advantage is determined not only by the type of polymerization and ease of use, but also by a large number of different types. It is worth saying that when performing the restoration of one tooth, a doctor can use about five varieties of the same material. Composites are divided into microfilled, minifilled, macrofilled and hybrid. All these names only indicate the number and size of solid particles that are dissolved in the organic resins of the composite.

Microfilled – the finest dispersed composites, they contain 37% of filler with a particle size of 0.01-0.4 µm. This composition makes it possible to carefully grind and polish the filling. As a result, the restoration will have a very smooth and shiny surface that will reproduce the optical properties of the tooth. Due to the small amount of hard filler, the filling will not be very durable. Therefore, the indications for using this material are mainly carious and non-carious defects of teeth that require aesthetic restoration and are not intended to withstand high chewing loads (cervical area and contact surfaces of 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 filler content is 50-55%. On the one hand, such a composition is the golden mean compared to coarse and fine-grained composites. However, grinding and polishing of fillings made of 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).

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

Hybrid photopolymers are the most popular composites today. They contain a filler with macro-, mini- and microparticles. The solid filler accounts for up to 70-80% of the total volume of the material. This combination of many particles of different sizes allows maintaining the high strength of the filling and achieving ideal aesthetics of the restoration during grinding and polishing. It can be said that hybrid composites combine the positive qualities of macrophilic and microphilic photopolymers. If the first experiments with hybrid composites did not cause significant resonance and popularity, then the further evolution of the material proved its undeniable advantage.

Totally executed composites are a type of hybrid composites in which the number of particles of different dispersion is precisely calculated and their optimal ratio is found. This has significantly improved the physical and chemical properties of the material, making it one of the most popular means for dental restoration. Many of them are successfully produced and used to this day: Spectrum THP (Dentsply), Valux Plus, Filtek Z250 (3M ESPE), Charisma (Heraeus Kulcer). However, the path of modernization of totally executed composites did not end there. The next stage of evolution was the discovery of micromatrix composites. This group of materials is distinguished by the fact that during production, all filler particles are pre-treated using a special technique. This allows to reduce the dispersion of the filler without losing the strength of the composite. Examples of this type of materials are: Point 4 (Kerr), Esthet X (Dentsply), Vitalescens (Ultradent).

Nanocomposites are a type 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 improves the aesthetic properties of the material without reducing the strength of the filling. One of the first nanocomposites was the photopolymer "Esthet X" from Dentsply.

Flowables are a special group of composite materials that combine the properties of mini-filled (filler dispersion is 1-1.6 μm), micro-filled (amount of inorganic elements is 37-47%) and hybrid (precise calibration and processing of the filler) composites. These composites are used for filling small cavities and fissures. Flowable materials have a physical property called thixotropy. This means that the material in a liquid state is able to maintain its shape until it is mechanically impacted. That is, the material begins to flow only when the dentist touches it with an instrument. Some of the popular flowable composites are Lаtelux flow (Latus, Ukraine), Filtek flow (3M ESPE, USA).

In addition to the various options in the composition of composites, they are divided by colors and shades. The need for such a classification is explained by the fact that tooth tissues (enamel and dentin) have different degrees of opacity (opacity, dullness). 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 the color of teeth changes with age. For example, young people have teeth of a low-saturated color and high opacity (dullness). In adults and the elderly, on the contrary, the teeth are brighter and more saturated, but at the same time more transparent. Based on these rules, manufacturers of dental materials have set themselves the task of creating the most universal set with a minimum number of syringes of composite. For example, GC (Japan) produces the Essentia set, which has only 7 shades and 4 modifiers (dyes). By the way, if you count all the shades of teeth on the Vita scale, you get 16 of them. However, GC focused not on the shades of teeth in general, but on the color characteristics of dentin and enamel. The creators of Essentia claim that the ability to correctly combine different shades of hard dental tissues allows you to reproduce any color of a light filling. For comparison, Heraeus Kulzer (Germany) took a different path. Their universal Charisma set contains three types of dentin composite of varying opacity. There are also 11 of the most common enamel shades that correspond to the Vita scale. Moreover, the set includes 7 additional shades. In total, the dentist has a palette of 23 composite options. However, despite the different approaches of the manufacturers, it is impossible to say for sure which light filling is better. The fact is that GC and Heraeus Kulzer produce high-quality products and have an equally high level of authority. Therefore, the types and names of light fillings are not as important as the ability to work with a certain set of composite.

Which is better: light-cured, chemical or cement filling?

Many people ask themselves: what is the difference between a light filling and a regular one? Which is preferable: a cement filling or a light filling? It is worth saying right away that there is no absolute favorite. Each material has certain advantages. Therefore, we will compare glass ionomer cements and composites (photopolymer and chemical) according to several criteria. The first factor is strength. Dental cements are less durable in their structure than composites. If we compare chemical and light-cured composites, then light-cured composites are more durable due to full hardening. The fact is that photopolymers are introduced into the tooth cavity in small portions. This allows for careful "curing" at each stage. Chemical composites are mixed and introduced in one portion. As a rule, even after thorough mixing, a certain amount of monomer remains in the filling, which reduces the strength of the filling. Therefore, in this category, a filling made of light-cured composite wins a well-deserved victory.

The second factor is resistance to a humid environment. All dental materials retain their properties better in a dry environment. However, moisture is present in the oral cavity all the time. Therefore, manufacturers strive to create a material that will be as resistant as possible to contact with oral fluid. Among the listed materials, glass ionomer cements have the highest moisture resistance. They are indicated for filling cavities in the gingival area, where the tooth is in continuous contact with liquid. Although composites have a certain level of resistance, it is less pronounced than that of glass ionomer cements.

The third factor is biocompatibility. In this category, glass ionomer cement also surpasses composites. This is due to the fact that photopolymers harden with a special lamp, which is a source of ultraviolet and infrared waves. They are capable of heating the pulp (nerve) to a temperature of 70-80 °, which can cause aseptic (non-infectious) pulpitis. As for chemical composites, it has already been said that after hardening, 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 possible shades and colors. Multi-stage introduction of the material allows layer-by-layer reproduction of all hard tissues of the tooth and achieving maximum aesthetics. Unfortunately, chemical composites and glass ionomers are less aesthetic. Although there are special "aesthetic" glass ionomers, working with them is not as convenient as with photopolymers.

The fifth factor is cost. Generally speaking, glass ionomer cement fillings are approximately 3-5 times cheaper than composite restorations. But this does not mean that they are more profitable to install than photopolymer fillings. After all, it has already been stated that composite is more durable than cement.

The sixth factor is ease of use. It is much more convenient to use a material that does not put the specialist in a "narrow framework". For example, in chemical composites and glass ionomer cements, the hardening process is activated after mixing. Therefore, the dentist has to adapt to time constraints. When placing a light filling, the specialist has the opportunity to work with the material until he successfully models the desired tooth surface. Also, when working with photopolymers, there is no mixing process, which also frees the dentist from additional work. And finally, the layer-by-layer introduction of the material allows dividing the restoration process into many small stages, which simplifies the restorer's work.

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

Indications

The light-curing composite is the most universal filling material. Therefore, it has the largest list of indications for use. A light-curing filling can be installed after treating carious and non-carious lesions (erosion, wedge-shaped defect, fluorosis, enamel necrosis, etc.). Photopolymers are also used in the final stages of pulpitis and periodontitis treatment. In case of dental injuries (fractures, enamel chips), an aesthetic restoration can be performed using a light-curing composite. If a person has pathological abrasion, but there is no possibility for immediate prosthetics, then a light-curing filling can be used for temporary restoration of worn tubercles. Before prosthetics with fixed structures (crowns, bridge prostheses), the tooth stump is of a certain shape and size. In order to give it the desired outlines, a light-curing composite can be used. 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 light-curing composite is a multi-stage and complex process that requires concentration and responsibility from the dentist. Preparing a tooth for filling involves removing damaged tissue and correctly forming the cavity. Softened dentin and enamel cannot be left in the tooth, as they can lead to rapid loss of the filling and various complications. The tooth cavity must be formed in such a way that the restoration has a sufficient support area. This factor is especially important in cases where a light filling is installed on the front teeth. Unlike barrel-shaped and cylindrical chewing teeth, incisors and canines have a more elongated shape. Therefore, their restoration is complex and requires the creation of retention points (additional support areas). Therefore, various steps are created during the formation of the cavity. If the degree of tooth destruction is too great, then the nerve is removed, a pin is installed in the canal and then a permanent light filling is installed.

Before installing the filling, the tooth cavity is subjected to acid etching. This is the so-called cleaning of the cavity walls from sawdust and other foreign elements. Moreover, due to the etching of the enamel, the dentinal tubules are opened, which are one of the factors of fixation of the filling. The next stage is the application of the adhesive system, which acts as a connecting element between the filling and the tooth. The quality of the adhesive system is no less important than the quality of the composite itself, because it affects the service life of the light filling. After the adhesive is cured, the final stage comes - the restoration itself, which involves the introduction of the filling material into the tooth cavity. As previously mentioned, the composite is introduced in small portions, which are approximately equal in volume to a grain of rice. Each portion is carefully pressed against the walls and bottom of the cavity, after which it is cured. This stage is repeated until the entire tooth is restored. When the modeling of all surfaces is completed, the finishing stage begins. It is necessary not only to create a shiny "enamel", but also to prevent the deposition of various substances on the restoration surface. Special disks, polishers, brushes and pastes are used to perform grinding and polishing. Disks and abrasive belts - strips are used to process contact surfaces.

It is not advisable to install a light filling on baby teeth and immature permanent teeth (up to 12-13 years old). This is explained by the fact that the dentinal tubules in such teeth are very wide. The composite elements can get too deep into the canals, penetrate into the pulp and cause pulpitis. The same applies to etching of hard tooth tissues, which is performed using orthophosphoric acid. Cases of pulpitis do not occur very often, but the probability of such an outcome of treatment is present. It is also worth saying that installing a light filling for children is not an easy task for the doctor, the child and his parents. Restoration with composite is a long and multi-stage process. Not every child has the patience and emotional balance to endure this procedure. Therefore, it is much more advisable to use glass ionomer cement in this case. To work with it, it is not necessary to drill the tooth and perform etching. Moreover, the material is introduced in one portion, which reduces the number of manipulations in the patient's mouth.

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

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

Contraindications for installation

Contraindications for placing a light filling primarily concern the use of etching and a photopolymer lamp. Regarding orthophosphoric acid, it was already said earlier that in baby teeth and unformed permanent teeth, the etching gel can have a toxic effect on the pulp tissue. Restoration using a light lamp is not recommended for people with pacemakers or visual pathologies. Other contraindications concern not only photopolymers, but also other filling materials. We are talking about those clinical cases in which filling is unacceptable. For example, the tooth crown is 90% destroyed, but a person wants to restore it with a composite. In this case, the filling is doomed to fall out, and the tooth - to re-treatment. Also, one of the contraindications for permanent filling is restoration in case of unfinished periodontitis treatment. Many people cannot tolerate the lack of aesthetics of a smile for a long time. Therefore, they often ask to complete the periodontal treatment and perform permanent restoration. If the doctor does this, the tooth may be removed in a few months.

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Consequences and complications

The widespread use of photopolymer composites guarantees the occurrence of various consequences and complications after treatment in some dentists. This is due to many factors. Firstly, popular, high-quality products provoke the appearance of a large number of fakes on the market. As a result, the use of non-original materials leads to the fact that the restoration is carried out conscientiously, but a month later the person returns to the dentist and complains that the light filling has cracked, fallen out or darkened. These phenomena can also be associated with a violation of the restoration protocol. Incorrect use of the adhesive system, poor isolation of the tooth from saliva, overestimation of the restoration contribute to the rapid loss of the filling. One of the most common symptoms after filling is toothache. People often ask the question: "What should I do if a light filling was placed, and the tooth still hurts?" According to medical protocols, it is necessary to monitor the dynamics of pain for the next 2 weeks. If the symptoms decrease, the cause may be hypersensitivity of the tooth to the composite. This condition does not require treatment and goes away on its own. If a light filling hurts acutely, this may indicate the development of pulpitis. In this case, you need to contact your doctor to determine the cause of the inflammation.

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Care and recommendations after installing a light filling

The first question that arises after treatment: how long after installing a light filling can you eat? As a rule, you should refrain from eating for the next two hours after the restoration. However, there is one nuance: on the day of filling, you must exclude the use of coloring foods (beets, black tea, coffee, chocolate, etc.). Such food stains light fillings, which reduces their aesthetic properties. Many people ask the question: "Does beer stain light fillings?" 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 filling if consumed frequently. The same answer can be given to the question: "Can I smoke after installing a light filling?" If the filling has changed color, then it is worth understanding the causes of pigmentation. After all, one of them is the development of secondary caries, the treatment of which will require the removal of the light filling. If less than a year has passed since the filling, then most likely the light filling will be replaced under warranty. If the restoration is in satisfactory condition, but the person smokes, drinks a lot of coffee and tea, then the top layer of the filling may have become cloudy. In this case, restoration of the light filling is recommended. In this case, the top layer of the filling is ground off, and a thin layer of "fresh" composite is applied to it. The light filling can also be whitened in the dentist's office. For this, various sandblasting machines (Air flow), grinding attachments, polishers, brushes, pastes, etc. are used. With their help, it is possible to remove the surface microlayer of the filling, which has accumulated pigments from food and cigarettes.

Patient reviews confirm the quality and reliability of photopolymer restorations. People are especially positive about aesthetic restorations on the front teeth. After all, such light fillings can improve a person's quality of life and increase self-esteem. As for the durability of composite fillings, everything is simple: if you regularly visit the dentist, follow the rules of oral hygiene, avoid heavy loads on your teeth and lead a healthy lifestyle, then the service life of a light filling can be measured in decades.