Caries infiltration (icon therapy) is a comparatively new technique that can be used to arrest early-detected, not yet advanced, carious lesions. No cavity needs to be prepared (no hole drilled) to make the initial (incipient) caries accessible to therapy. The treatment is completed painlessly in one treatment session. Caries infiltration is a so-called microinvasive procedure and is based on the principle that a carious initial lesion (incipient tooth decay) is infiltrated (penetrated) with low-viscosity (low-viscosity) resin in the demineralization (decalcification) phase before cavitation (a “hole”) is formed. The hardened resin prevents further penetration of caries-causing germs, the carbohydrates necessary for their multiplication and their metabolic product acid, which demineralizes the tooth structure. Long-term studies are not yet available, but it is nevertheless foreseeable that the method, in addition to the optimization of oral hygiene technique, dietary management and regular dental check-ups, is a useful supplement to prevent the progression of caries.
Indications (areas of application)
An understanding of how caries develops is necessary in order to make the correct indication: first, the acid secreted by the caries bacteria dissolves the mineral components from the enamel structure. This creates pores; however, the enamel structure is still temporarily preserved until it finally collapses upon further exposure to acid and demineralization – the defect (the “hole”) is created. It is crucial for the successful implementation of the caries infiltration technique that the enamel does not yet have a defect. Thus, only:
- Proximal (interdental space) lesions with an intact surface that are
- Are enamel delimited and
- Have penetrated at most into the first third of the dentin (dentine) (D1 lesions).
- Also incipient smooth surface caries, which meets the above conditions, can be treated.
Contraindications
- D2 and D3 lesions (caries extending into the second and third thirds of the dentin) are an absolute contraindication.
- In addition, the lesion to be treated must be bordered by enamel, i.e., it must not reach the dentin in the surface area, because the procedure technique is designed to infiltrate the enamel and not the dentin structure. Thus, the procedure is unsuitable for tooth neck lesions.
Before the procedure
The procedure requires radiographic bitewing images for diagnosis, which must be used to precisely define the depth of penetration of the proximal caries (on the interdental surfaces) in order to make the decision for caries infiltration.
The procedure
The aim of the procedure is to fill the porosities in the demineralized enamel with thin-flowing resin, thus preventing further demineralization processes. Since the salivary surface of the carious lesion is clinically intact due to remineralization, the superficial minerals must first be dissolved by acid in order to be able to reach the underlying pores with the resin. Accordingly, the procedure is divided into the following steps:
- Cleaning the tooth with polishing paste and dental floss.
- Applying rubber dam (tension rubber to shield the tooth to be treated from the rest of the mouth) to keep saliva out and protect the gingiva (gums) from the acid
- Separating (gently pushing the teeth apart in the approximal space to be treated using a wedge).
- Insertion of the applicator (special foil pocket for the acid) and etching of the tooth surface to be treated with 15% hydrochloric acid gel (HCl gel) for two minutes;
- Thorough rinsing and very good drying with air or alcohol over defined time intervals.
- Insertion of the applicator and infiltration of the plastic for 3 minutes.
- Removal of the excess plastic
- Light polymerization (curing of the plastic, where the chemical reaction is triggered by light).
- Repeat infiltration, excess removal and polymerization.
- Final polish
