Secondary caries is a new carious process that occurs in previously treated and sealed teeth, more often associated with insufficient treatment of the cavity and poor–quality filling. Symptoms are not pronounced for a long time, the color of the tooth enamel changes over time, chipped fillings appear, unpleasant sensations when exposed to cold, hot, sweet and sour. Due to the asymptomatic course, caries can be complicated by pulpitis. It is diagnosed by dental examination, radiography and transillumination of the tooth. Treatment includes removal of the old filling and the affected part of the tooth, followed by refilling.
K02.8 Other dental caries
Secondary caries is often called recurrent, but some specialists share these terms. Recurrent caries appears under the filling if the initial treatment was performed poorly, and the necrotic areas of the tooth were not completely removed. Secondary caries refers to caries that has arisen next to the filling as a new lesion. About 40% of all therapeutic procedures in outpatient dentistry are associated with the treatment of secondary caries. According to research, pathology more often affects children with a changeable bite and adults aged 20-40 years. Most often, repeated caries occurs around cement fillings and amalgam fillings, statistically less often – around restorations with composite materials of chemical and light curing.
The appearance and progression of pathology is influenced by a number of interacting factors. The level of susceptibility of the hard tissues of the tooth to caries, oral hygiene is important. Local causes of secondary carious lesions, as a rule, are associated with the properties of the seal:
- Poor contact of the seal with the cavity. Poor quality of the treatment of the carious cavity and non-compliance with the algorithm of filling lead to poor adhesion of the contact surfaces of the tooth cavity and the filling material. This causes the formation of micro-cracks and cracks, where plaque accumulates and bacteria multiply.
- Seal with high shrinkage. The physical properties of the filling material cause a gradual decrease in the volume of the seal – its shrinkage. The walls of the cavity are exposed, a space is formed between the edge of the filling and the hard tissues of the tooth. Open enamel and dentin begin to break down under the influence of oral fluid and plaque.
- Insufficient grinding and polishing of the seal. Poorly treated surface of the seal enhances the degree of adhesion of plaque on the hard tissues of the teeth. Bacteria that secrete acids that destroy enamel and dentin settle in surface defects. An unevenly processed seal increases the likelihood of microcracks and chips.
Caries is a systemic disease, and in addition to local causes, a number of general factors also affect the likelihood of its occurrence. Repeated studies involving residents of regions where there is little fluoride in the soil and water (within 0.05-0.5 mg/l) have shown that primary and secondary caries are common in 97% of young patients and in 24% of patients after 44 years. Also, a likely factor in the development of secondary changes may be the rejection of immunomodulatory therapy in the acute course of caries and treatment with remineralizing solutions of the enamel surface before and after filling the cavity. The qualification of a dentist-therapist is also important: poor-quality filling and violations of the treatment of the tooth cavity are often a sign of insufficient training of the doctor.
The development of the disease goes through several stages. First, a marginal micro-gap is formed between the seal and the adjacent wall of the cavity, where the oral fluid with acids and enzymes in the composition seeps. Subsequently, oral bacteria enter the formed micro-slit. Bacteria produce acids that destroy the enamel and dentin of the tooth. Dentin is more susceptible to destruction, since it contains many organic compounds. Acids and enzymes of the oral fluid also destroy the structure of the composite seal. This leads to the rejection of the filling from the walls of the carious cavity. Pathoanatomic examination shows areas of decay and demineralization of enamel and dentin with remnants of destroyed filling composition.
Pathology can be asymptomatic for a long time. Clinical signs rarely appear earlier than 3-6 months after treatment. If defects on the seal occurred earlier than this period, they are usually associated with other reasons. Tooth pain 2-4 weeks after treatment may indicate recurrent caries, errors in treatment or opening of the pulp horn with careless work of the doctor.
External signs include enamel pigmentation near the edge of the seal, often in the form of a rim. The seal can also change color. The tooth becomes grayish, modified dentin shines through the enamel. On the incisors, these changes are noticed earlier than on the molars. Sometimes there are cracks and chips of tooth enamel and fillings. With pronounced defects, it is possible to detect the mobility of the seal; if caries has been developing for a long time, and the cavity increases, the seal may fall out. Bacterial plaque accumulates in the cracks, which leads to bad breath.
When caries deepens, patients complain of aching pains when brushing their teeth, a painful reaction to sour, sweet, hot and cold. Nerve endings in the tubules of exposed dentin react to chemical and temperature stimuli. Sometimes the problem can only be indicated by a feeling of a broken tooth in the area of the treated tooth. Developed secondary caries is often accompanied by swelling, swelling and soreness of the gums next to the sealed tooth, gums can bleed when eating and brushing teeth. With a chewing load, the tooth may give off a slight pain. In children, the process is often observed in the area of the necks of the teeth, there are complaints of pain when exposed to hot and cold.
A common complication is tooth pulpitis. It occurs when, in the absence of timely treatment, the destruction of enamel and dentin reaches the neurovascular bundle (pulp) of the tooth. At this stage, it is necessary to depulpate the tooth. Pulpitis is determined by severe, acute and constant pain, increasing by night. The pain appears for no reason, can spread to the entire jaw, capture the branches of the trigeminal nerve. If pulpitis is not treated, it goes into a chronic stage. Chronic pulpitis is dangerous due to its painless course for a long time. At the same time, tissue necrosis and infection affect the parotid tissues, periodontitis occurs – inflammation of the ligaments of the tooth. The subsequent spread of infection can take over the jaw bone, up to osteomyelitis.
The lesion of a previously treated tooth is detected by a dentist at a repeat appointment with the help of a dental examination and hardware diagnostics. During the examination of the patient, the doctor finds out the reaction of the tooth to stimuli, the presence and degree of pain, the time of symptoms. Anamnesis collection is necessary to differentiate secondary caries from recurrent caries. The survey includes:
Dental examination. It is carried out in order to identify changes visible to the naked eye and their differential diagnosis. During the examination, a probe and a mirror are used, with their help the condition of the seal is determined:
- The seal is tight, the probe does not get stuck when moving along the edge of the seal, the gap is not determined. This may mean that the symptoms are related to another disease, or recurrent caries has developed under the seal.
- The probe gets stuck when running along the surface of the filling and the tooth, there is a gap where the probe penetrates, the dentin is not open. This indicates a filling defect and the initial period of development of a new carious process.
- The probe falls into the gap to the depth of the dentin, the study may be accompanied by pain symptoms when touching the dentin. Pain is a sign of enamel destruction and dentin exposure, which indicates a large carious cavity.
- The chip of the seal is noticeable, its mobility, it may partially fall out. The tooth is severely destroyed, it is possible to assume complications of caries in the form of pulpitis.
Hardware diagnostics. It is required to clarify the diagnosis and the degree of pathology development. Includes sighting radiography, transillumination, radiovisiography. According to the X-ray image, the depth of the carious process under the seal and next to it is estimated. The method of transillumination allows you to distinguish healthy tissues from the affected ones by special translucency. The carious cavity under the seal looks like a brown hemisphere. Visioradiography is used to assess the condition of seals made of various sealing materials.
The choice of tactics depends on the localization of the carious lesion, its prevalence and depth. Treatment may consist in removing the old seal and replacing it with a new one or restoring the modified part of the seal. If secondary caries is limited in localization and is located on the chewing surface, necrotic tissues can be removed, this part of the cavity can be formed and sealed with the same material.
If caries is spread around the filling or affects several places where the filling fits to the tooth, then the filling is completely removed together with necrotic tissues, the cavity is formed anew, and the defect is restored by layer-by-layer application of photopolymer. The whole procedure is performed under anesthesia, it is mandatory to carry out antiseptic treatment of the cavity and the use of a therapeutic pad.
In the case when the process affects the pulp chamber of the tooth, and the patient has already developed pulpitis, depulpation (removal of the “nerve”), treatment and filling of the channels, and then restoration of the tooth cavity with a seal or tab is carried out first. In case of severe destruction of the tooth crown, restoration is carried out with the help of an artificial crown. The most appropriate method of treatment and restoration of the function and appearance of the tooth is chosen by the dentist, taking into account the clinical situation of the patient.
Prognosis and prevention
Prevention and elimination of complications is the task of the dentist even at the stage of primary treatment. The analysis of the state of the dental system, the collection of anamnesis about concomitant diseases, the assessment of oral hygiene allow us to assess the likelihood of developing caries in the future. Prevention is more often reduced to high-quality treatment of the cavity and subsequent sealing with control of the fit of the seal at the edges. To exclude secondary caries during filling, it is preferable to use bacteriostatic materials, for example, glass ionomers. On the part of the patient, prevention is the observance of oral hygiene and the passage of a routine examination at the dentist. In the acute and acute course of caries, periodic immunomodulatory therapy and fluoridation of teeth are indicated. With timely access to a doctor, the prognosis of caries treatment is favorable.