Caries in the spot stage and superficial lesions
At the earliest stages of the carious process development, which include initial caries (spot stage) and superficial caries, pathological changes are localized exclusively in the outer layers of the tooth.
Clinically, these conditions manifest quite distinctly. Upon visual inspection, the dentist discovers characteristic foci of demineralization. They appear as matte or pigmented spots on the surface of intact enamel. With further progression of the process, superficial defects of the enamel cover are formed. In clinical practice, such lesions are often demonstrated using the example of the upper incisors, where they are most accessible for direct visual control and aesthetically significant for the patient.
Innovative treatment without preparation: the Icon technique
For a long time, the only way to stop the carious process was considered to be the excision of affected tissues. Today, the German Icon technique is successfully used to treat superficial caries.
The main and undeniable advantage of this technology is that treatment is performed absolutely without preparation. The doctor does not need to use a dental drill, which eliminates the loss of healthy hard dental tissues and minimizes stress for the patient.
The essence and mechanism of action of the infiltration method come down to three sequential stages:
- Chemical surface preparation. A specialized solution is applied to the affected area. Its task is to react with hard tissues, changing the spatial structure of hydroxyapatite crystals and expanding the interprismatic spaces of enamel. This creates the necessary micro-porosity.
- Infiltration. An active substance — a special infiltration gel — is introduced into the formed microscopic pores. Due to its high fluidity, it penetrates deep into the structure of demineralized enamel, filling all voids.
- Polymerization. The final stage is the curing of the introduced gel. The process is carried out via photopolymerization — under the influence of a dental light source, the infiltrant hardens, reliably sealing the affected area and restoring the optical properties of the tooth.
Diagnostic criteria for moderate caries
If the process was not stabilized at the superficial lesion stage, it inevitably spreads deeper, turning into the moderate caries stage.
The key diagnostic criterion for this form of pathology is the presence of a clearly formed carious cavity. Unlike superficial defects, in moderate caries the zone of destruction is no longer limited only to the enamel barrier. The cavity freely spreads within the entire thickness of the enamel, overcomes the amelodentinal junction, and reaches the middle layers of dentin. It is the depth of penetration of the infectious process and the involvement of dentin that determine the tactics of further dental intervention.
Briefly: answers to topical questions
Which carious cavities belong to Class I according to Black?
Class I according to Black includes carious cavities localized in the area of natural pits and fissures of the teeth. The following clinical variants of lesions are distinguished:
- Fissure and occlusal caries — involvement of the fissures of molars and premolars, as well as the occlusal surface of molars.
- Natural pit caries — involvement of natural pits of premolars, blind pits on the buccal or oral surface of molars, as well as on the oral surface of anterior teeth (more often the maxillary central and lateral incisors).
- Combined lesion — simultaneous involvement of the buccal and occlusal surfaces of molars.
Which carious cavities belong to Class II according to Black?
Class II according to Black includes carious cavities localized on the lateral (approximal) surfaces of the posterior group of teeth. Depending on the location of the defect, the following localization variants are distinguished:
- Below the contact point — the lesion is localized below the contact zone with the adjacent tooth.
- In the contact point area — the lesion is located directly at the site of tooth contact.
- Above the contact point — the defect is located above the contact zone.
- With total involvement of the approximal surface — the entire approximal surface of the tooth is affected.
What are the main stages of carious cavity preparation according to Black?
The process of carious cavity preparation is strictly divided into four main sequential manipulations. The following stages are distinguished:
- Opening of the carious cavity — ensuring free access to the defect.
- Necrectomy (necrectomia) — complete excision and removal of necrotic, softened, and pigmented (infected) dentin.
- Shaping of the cavity — giving the cavity a specific shape that promotes the best adhesion of the chosen filling material.
- Finishing — final trimming of the cavity margins, including the removal of damaged enamel areas, smoothing of edges, and creation of a bevel.
What geometric shape should a classically prepared Class I carious cavity have?
A classically prepared Class I carious cavity must have a strictly box-like shape. This configuration is necessary to ensure the stability of the filling and the tooth itself against mechanical loads arising during the chewing process.
Main characteristics of a box-like cavity:
- Floor — flat, positioned perpendicular to the direction of masticatory pressure.
- Walls — vertical, meeting the floor of the carious cavity strictly at a right angle (90°).
The exception is small cavities in the area of natural (blind) pits on the buccal or oral surface of molars — they are given an oval shape.
In which cases is it necessary to form an additional step (extension) when preparing Class II cavities?
When preparing Class II carious cavities, the formation of an additional step on the occlusal (facies occlusalis) surface is necessary in the following clinical cases:
- Difficult access — localization of the lesion on the approximal surface in the cervical area with tight contact with the adjacent tooth.
- Combined lesion — simultaneous involvement of the approximal surface and fissures on the occlusal surface by the carious process.
- Extensive carious process — destruction of the approximal surface and marginal ridge with extension to the occlusal surface.
The creation of a step provides access, improves the retention of the filling material, and evenly distributes masticatory pressure.
What should be the ratio of the dimensions of the main cavity and the additional step during Class II preparation?
The dimensions of the additional step during Class II cavity preparation must strictly correlate with the parameters of the main cavity and the anatomy of the tooth. The following requirements are distinguished:
- Width — must correspond to the width of the main cavity or be smaller than it (in case of extensive involvement of the approximal surface).
- Length — ranges from 1/3 to 2/3 of the length of the occlusal surface (affected fissures are excised and included in the step).
- Depth — located 1–2 mm below the amelodentinal junction.
If the dimensions of the main cavity and the additional step do not match, there is a high risk of losing (dislodging) the filling.
What is the principle of prophylactic extension of the carious cavity according to Black?
The principle of preventive extension of the carious cavity ("extension for prevention"), proposed by G.V. Black, consists in the wide excision of caries-susceptible areas of hard dental tissues.
The essence of the method lies in expanding the boundaries of the cavity being prepared, in particular in excising caries-susceptible areas of fissures to immune (caries-resistant) zones of the tooth. This approach is used as a preventive measure to prevent the occurrence of secondary and recurrent caries. As a result of such preparation, an extensive box-like cavity is formed.
What surgical accesses can be used to prepare a Class II carious cavity?
The choice of surgical access in the preparation of Class II carious cavities depends on the location of the defect and the presence of adjacent teeth. There are two main types of access:
- Direct access is used when there is free approach to the affected contact surface, for example, in the absence of a neighboring tooth. Preparation is performed without extending the cavity onto the occlusal (facies occlusalis) surface.
- Occlusal access is the most common method. Trepanation of the occlusal surface is performed with a diamond round bur, followed by widening the access with a fissure bur and removing hard tissues overhanging the carious cavity.
Class and exam questions
What is the main advantage of the Icon technique?
The main advantage of the Icon system is that superficial caries treatment is performed without preparation, meaning without the use of a dental drill and tissue excision.
Which enamel structures are affected when using the Icon solution?
The special solution acts directly on the hydroxyapatite crystal structure and enamel interprismatic spaces, preparing them for gel penetration.
How to determine the transition from superficial to moderate caries?
The diagnostic criterion for moderate caries is the formation of a cavity that not only destroys the enamel but also extends deeper, reaching the middle layers of dentin.
What else to study on this topic
- Demineralization foci and visual diagnosis of caries
- Histology of enamel interprismatic spaces
- Properties of hydroxyapatite crystals under acid exposure
- Photopolymerization in dentistry: physical principles
- Topography of the middle layers of dentin
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