It is the filling of the tooth, which has been damaged by cavities or trauma. In the past, when there were no white substances, it was said, they taught us, and so it is also in the literature as obturation, when the lesion was not large, and the concept of reconstruction was only in the case that included most of the surfaces of the tooth. Nowadays, due to the use of white materials the work method is completely different from what it was before and the tooth is reconstructed in small portions and for that reason today it is denominated restoration of the tooth and not obturation of the tooth. So, I will refer to a restoration that is performed in two main situations. 1) due to trauma or fracture of the tooth 2) due to cavities-caries.
Fracture and trauma of the tooth: The treatment procedure is anti-invasive, with a maximum preservation of the healthy material of the tooth, except rounding the limits of the fracture or eliminating weak parts of the tooth .Usually requires local anesthesia because the internal part of the tooth called dentin is exposed and is very sensitive even when drinking water and there is no other option as to treat the tooth.
Caries: This is the disease of the teeth, caused by the damage of the bacterial plaque on the teeth, which causes to the dental tissue been dissolved. As a result, a cavity (dental caries), which requires treatment as soon as possible, to prevent more severe injury to the pulp of the tooth (nerve and blood vessels) or more severe loss of tooth later on.
Prevention: After the tooth erupts in children you can seal the fissures of the teeth with a specific material for this purpose, as well as a good and proper oral brushing, use of accessories such as toothpaste, mouthwash, dental floss, interdental brushes and buccal irrigators. And of course, regular visits to a dentist once or twice a year.
Where dental caries is located: After the eruption of the tooth there is a tendency to develop in the chewing area of the molars. It is therefore recommended to seal the fissures of the tooth in children according to medical necessity depending on the size of the fissures and whether they are open or not. After several years from adolescence the tendency to develop dental caries is between the teeth that then progresses and expands over time to the entire tooth, as long as the tooth has not broken or is visible caries can only be discover with radiography so it is recommended to visit at least once a year for periodic checkup, in order to detect the development of decay as soon as possible. In a later adult stage due to retraction of the gums and exposure of the roots of the tooth, the lesion may be in this area. This is the most dangerous damage to the tooth, due to the depth and speed of the process, near the pulp (nerve, blood vessels), can even reach a situation that in a few months is necessary to remove the tooth.
The methods of treatment: caries removal is performed by the dentist with rotating instruments and later with manual instruments that the tooth is then restored with different materials, for example metal (amalgam), or white as a composite resin or with glass Ionomer that release Fluor and one is adhered perfectly to the tooth. And if dental caries is very large it is recommended to carry out laboratory reconstructions called INLAY / ONLAY
So, let’s detail the different types of restorative materials that exist today.
Amalgam: is a metal alloy containing silver, tin,copper mixed with mercury, after several minutes the soft material, hardens into a hard and resistant material that withstands high pressures (think as if it were the cement mixed with sand and water, after a few hours it becomes hard and resistant concrete). Although the relationship between the various components has undergone improvements since it was invented some 150 years ago, this material has been in use since then to this day.
Advantages: Easy to mix, the technique is simple and very important does not need special application conditions, linked to the tooth, oral cavity, or professional, it is simple and also very cheap. It does not require expensive instrumental or special equipment accompanying the application technique therefore the use to date is very extensive all over the world.
Disadvantages: of course, the metallic color that in the 21st century is not aesthetically acceptable, as it was in the past that the patients did not pay much importance to it, as long as we did not have any substitute yet. The preparation of the tooth requires the removal of more tooth tissue including normal and healthy tissue.
The disadvantage on the health of the teeth is important because the problems caused by changes in temperature when eating or drinking are: 1) the phenomenon of hypersensitivity of the tooth that appears when the temperature passes through the metal and is transported to the depth of the tooth to the nerve, which causes acute and momentary pain is very noticeable after the treatment and usually disappears up to two months, if the tooth does not withstand to the stimulus should often perform a root canal treatment
2) the change of temperature of the teeth and the amalgam leads to another phenomenon of volume changing in which the heat produces expansion and the cold the contraction. and this happens to a tooth and amalgam at the same time, the problem is that the amalgam and the tooth do it in very different percentages that over time causes a lack of sealing in the margins of restoration with the appearance of secondary caries which determines to replace the restoration. In addition, during expansion of the amalgam that is much larger than the tooth causes fractures and cracks in the tooth, and patients when they reach the clinic can see the reconstruction is intact but the wall of the tooth is fractured and absent.
Mercury and poisoning. A question that dentists have to answer very often
The problem appears when the old restoration is removed at that time the mercury is evaporated into the air, and is inhaled by the patient and the professional team, so the team works with a strong suction system and uses protective masks. exposure to the patient is minimal or null because it is a single non-repetitive event unlike the medical staff in which this action is performed every day and usually several times a day therefore the potential for toxicity or poisoning by mercury is risky for medical equipment and zero for the patient. In addition, and in accordance with the recommendation of the Ministry of Health in Israel and this is a transcription of the website
“There is certainly no justification for replacing amalgam restorations for aesthetic or health reasons (for fear of the presence of mercury). Amalgam mercury is released into the air specifically during the evacuation of restorations in order to replace them Therefore, restorations should not be replaced in the mouth unless there is a need such as tooth decay or fracture”
At the end of the 80’s began to appear new materials for restorations of anterior teeth and with the desire to get good materials for reconstructions in the posterior teeth, thanks to the development in recent years have allowed us to get more materials, more resistant to the forces of mastication, and obtain an excellent aesthetic result.
Advantages: An excellent aesthetically material for the purpose that was invented as an alternative to amalgam. It does not require the removal of a large amount of dental tissue only in the area of caries ensuring maximum preservation of dental tissue. There is no temperature transfer to the pulp of the tooth / nerve causing hypersensitivity. The volume changes of the material with the temperature are close to that of the tooth. High resistance to chewing forces. Contains no mercury Disadvantages: material more expensive than amalgam, hand instruments, various accompanying materials and equipment that increase costs, more complex work techniques and longer implementation time because the material hardens only in layers or small portions. Very sensitive material that needs special conditions for its implementation, such as an absolute totally dry medium sometimes impossible to obtain in the mouth of certain patients, or in certain areas. The material that connects to the tooth loses the bond or connection over time. A durable life that is much shorter than the amalgam and requires maintenance or replacement several times in our lives. In spite of the failures the statistics are similar to those of the amalgam
It also includes a substance called Bisphenol A which is a chemical found in the plastic industry and serves as a building block (monomer) to the resin. Although there is still no evidence of harm to patients using this material in mouth restorations, we are now aware of the problem and hope the dental industry will find a solution to the problem. It requires great skill in the technique by the dentist to achieve an optimum point of contact between the teeth and good sealing in the limits that if it is not achieved will produce food impact between the teeth, and the food compaction will determine deterioration and the most damage severe to the teeth and gums, lack of sealing gives hypersensitivity and the appearance of secondary caries. Therefore, a large percentage of dentists prefer not to perform composite resin restorations on the posterior teeth
The glass ionomer is the latest material added for tooth restoration. The material consists of glass particles of silicate, alumina (silicon dioxide) and Fluor all the minerals are mixed with a liquid that after mixing and when placed in the tooth has a process of biological and chemical connection with the dental tissue. In fact, it is the only biological material currently available for use in dentistry
Advantages: Chemical connection with the tooth. biological material to the tooth which is very suitable for use in children, releases fluoride over time after treatment, which reinforces the adhesion of the material to the tooth and prevents secondary caries. Same ratio volume variation with temperature with a perfect sealing in the margins, can be used on the posterior teeth and on the exposed root zone with minimal removal of dental tissue and on the erosion area of the root without drilling and without anesthesia. A substance that does not bother to be in a humid environment is therefore very suitable for use in children. Disadvantages: A correct or appropriate aesthetic cannot yet be achieved as resins. In very large restorations they tend to break. But statistically they are similar to amalgam restorations
INLAY / ONLAY in recent years has created another type of reconstructions that combines high aesthetic and biomechanical properties. They are based on resins, porcelains, zirconia, which are manufactured in the laboratory and then are cemented to the tooth Advantages: high esthetics and optimum strength. Suitable for posterior teeth with very large coronary destruction and in those teeth, that have not yet undergone root canal treatment. Disadvantages: require at least two sessions including tooth preparation, impression and send them to the laboratory for manufacturing and another appointment for cementation. It requires special adhesives for this purpose. The treatment is very expensive because the execution process is similar to that of the crown and requires greater skill for its implementation.
Restorations Whites or grays-metal? It is clear that the size and location of the restoration within the tooth and the location of the tooth in the mouth is very different in each case but for simplicity I recommend in anterior teeth where aesthetics are important and visible restorations based on composite resins, and where there is no aesthetic problem I would recommend glass ionomer. In the posterior teeth, I recommend a biologically compatible material with the tooth as the glass ionomer, as a second-choice resins and when the destruction is important a laboratory reconstruction. And last choice is the amalgam, the recommendation is medical without entering the financial aspect.
How long is a reconstruction last? This depends on many parameters of the size of the reconstruction and its location which is very different in each case. Amalgam restorations are very durable even, for over 20 years, resins reconstructions for more than 5 -7 years and the time is shorter due to color change, fractures or lack of sealing in the margins sometimes lasting only two or three years, but as I mentioned above, it all depends on the size and location of the restoration
What is the secondary caries or caries under the restoration? A big mistake is to think that once the tooth has been restored it will be free of caries for life, because the tooth is still sensitive at the margins of the connection between the restoration and the tooth, and sealed failure in this area can cause secondary caries, or their recurrence, as I mentioned above
About to temperature changes that are different between the teeth and the restoration which will cause a small gap, so the microbes filter and produces cavities again , because of this the preference is the use of restorations based on glass ionomer. we also see the development of caries under the restoration this means that due to the retraction of the gums and the food impaction develops deep caries near the restorations without direct connection to the restoration and it is necessary to remove the perfect restoration to access the area carious
How can we eliminate dental caries without damaging our teeth? the first thing that is needed is to access and reach the area where the caries is, for this purpose in most cases we sacrificing healthy tooth tissue, because there is no other option, unlike when the caries is visually exposed, but that is only happens when has been a long time without resorting to treatment and the tooth is usually broken. the treatment is done with small rotating burs that rotate at high speed, and that allows in less than a minute to reach the caries area, most of the caries is eliminated as well, and in the end, it is advisable to finish elimination of caries with use of manual instruments which facilitates the removal of carious dental tissue that is soft unlike to healthy dental tissue that is hard and cannot be shaved. After removal, weak parts or pieces of dental tissue are removed which will disintegrate later after reconstruction and cause a lack of sealing and secondary caries. For amalgam reconstruction, the material should be given sufficient volume to provide increased strength because in small thicknesses the material is fractured therefore healthier dental tissue must be sacrificed for this purpose. Unlike white reconstructions, only caries is eliminated without sacrificing healthy tooth tissue, so white materials are recommended for dental reconstruction. In recent years, studies have shown that using glass ionomer restorations without eliminating 100% of tooth decay, after several months the affected area becomes healthy and protective tooth tissue. Therefore, it is the most recommended material for dental restoration with dental caries including very close to the pulp of the tooth (nerve)
If there is any slight hipersensivity or pain root canal or restoration? from the histological point of view at the moment that the caries has reached the dentin there has been irreversible damage to the dental pulp, but the teeth clinically usually do not cause any pain all the life that is why we work from the clinical point of view. otherwise we should do root canal to each tooth that has caries. So, this time I will answer from the end to the beginning a tooth after a root canal treatment increases the tendency to break or fracture, therefore, is forced to perform the crown, to prevent tooth loss so it is a series of treatments that involve great costs. Therefore, it is best to avoid doing the root canal treatment as much as possible. This is the line that guides me. And the answer is first to remove the caries in the case that the pulp was discovered is necessary to do a root canal treatment, but in case we have not discovered the pulp, but we are very close to it is advisable to perform a restoration based of glass ionomer that protects the tooth is biological and does not destroy the pulp
What does decay look like? The characteristics of caries are light yellow, brown, and even black. But the defensive and healthy dentine that forms in front of the dental caries can have the same colors, therefore, the color will not determine if there is caries or not, only the texture of the dental tissue examined by the dentist with instruments that in the end It is a tip that checks and scrapes the dentinal tissue if it is soft and hooked. It shows the presence of caries in the case of normal and healthy tissue is hard and the tip slips is like the sensation of scraping on wood or on metal.