PHARMACOLOGICAL MANAGEMENT OF CARIES
Case Report 1: Glass Ionomer Combined With Ozone Treatment
GI cements pharmacologically assist with the remineralization of carious dentin by providing a source of fluoride, calcium, or strontium ions (depending upon the GI used). These ions can penetrate more than 100 µm into dentin to assist with the formation of hydroxyl and fluorapatite in the demineralized tissue. GI cements have further benefits when treating caries as they prevent demineralization at the perimeter of the restoration, unlike composite resins which offers no such protection.
The following clinical case shows increased radiopacity that occurred under a self-curing GI cement restoration treated with ozone.
A patient presented with a large carious lesion on a lower second molar (Figure 2). Although the lesion was asymptomatic, a periapical radiograph showed extensive caries that may well have resulted in a pulp exposure during cavity preparation.
Overlying caries were removed and the lesion was etched with phosphoric acid for 5 seconds, then washed and dried with oil-free air. The residual softened caries were treated with ozone for 40 seconds using a HealOzone (KaVo) unit. Following this the cavity was restored with a self-curing GI cement (Fuji Triage [GC America]). Extensive radiolucency below the restoration is apparent, immediately after restoration placement (Figure 3). However, 12 months later, when the patient was recalled to have a composite resin (Ice [Southern Dental Industries]) placed over the GI, a further radiograph shows a marked improvement in radiopacity below the GI base (Figure 4).
Case Report 2: Glass Ionomer Used With Silver Fluoride and Potassium Iodide
The following case report describes a pharmacological approach to managing a carious lesion using AgF/KI and GI cement:
The patient presented with occlusal caries on a lower molar in Figure 5.
Enamel was removed to gain access to the lesion. A moat was then prepared in sound dentin with a No. 3 slow speed round bur, at the dentin-enamel junction (DEJ) around the perimeter of the caries (Figure 6). Next, the preparation was etched with 37% phosphoric acid for 5 seconds, washed with water, and dried with oil-free air. AgF was then applied to the preparation, followed by KI until the precipitation turned from cloudy white to clear. The cavity was washed and dried again with oil-free air (Figure 7).
After isolating the preparation from moisture with strategically placed cotton rolls, a self-curing GI cement (Riva [Southern Dental Industries]) was placed into the preparation to slightly overfill the preparation. AgF/KI enhances the bond strength between self-curing GI and dentin. A 3 cm square piece of a plastic freezer bag was placed over the GI and the patient asked to close in into centric occlusion for 4 minutes until the GI had cured (Figure 8). After curing, minimal contouring was required to complete the restoration (Figure 9).
INFORMED CONSENT IS IMPORTANT
Intentionally leaving caries under a restoration may have the potential to lead to legal problems if a patient is unaware of the nature of procedure. This is especially true if another practitioner should have to radiograph the restoration and be unaware of this treatment protocol. Dentists who carry out remineralization procedures are well advised to provide their patients with written explanatory notes about the procedure and the benefits that can be achieved.
CONCLUSION
Restoration of teeth by amputation is a caries management model that often leads to the ongoing iatrogenic destruction of the dentition. The pharmacological management of caries is a conservative alternative that enables the remineralization of caries infected teeth to form a decay resistant layer at the base of a restoration.
AgF has been used to arrest caries, primarily in deciduous teeth since the early 1970s. After application, free silver ions react with oral sulphides to form silver sulphide, staining the teeth black. The application of KI immediately after AgF application forms silver iodide. This is a low-solubility creamy-white precipitate with significant antibacterial properties that inhibits silver staining.
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