Silver Modified Interim Therapeutic Restoration

The silver modified interim therapeutic restorative technique is built upon several different components or steps within the frame of minimally invasive restorative dentistry: the partial removal of carious tissue using hand instruments, the use of SDF to arrest caries progression, the placement of a material to "seal off" the affected tissue, and the placement of a final restoration. SDF (ie, 38% with approximately 44,800 ppm of fluoride) is a colorless or factory tinted fluoride delivery solution with the ability to arrest active dentinal caries lesions.¹ In caries lesions treated with SDF, the remnant ioni    c silver inhibits further biofilm formation and makes the treated dentin more resistant to cariogenic bacteria, thereby preventing further development and cavitation. SDF discolors the arrested carious tissue with a characteristic black stain²; however, the final restoration placed over it will cover this discoloration. After the application of the SDF, the treated tooth is immediately restored or sealed off with either a dentin substitute, mineral trioxide aggregate (MTA), or a glass-ionomer cement.² After that, and within a reasonable time frame, a stainless steel crown is placed over the tooth to serve as an interim or "final" restoration.

A 7-year-old patient presented to the clinic with molar-incisor hypomineralization syndrome.³ This syndrome is defined as the hypomineralization of systemic origin of one to four permanent first molars, frequently associated with affected incisors.³ This condition presents as demarcated enamel opacities of different colors, which often undergo post-eruptive breakdown and subsequently develop caries.³ In this patient, all of the permanent first molars were affected. The patient was asymptomatic, and there were no radiographic signs of pathosis present, except for in the occlusal area of tooth No. 19 (Figure 1 and Figure 2). Using hand instrumentation, the carious dentin on tooth No. 19 was partially removed, leaving affected dentin over the pulpal floor. Next, a 38% SDF solution was placed over the tooth (Figure 3). In this particular case, the patient was dismissed and returned 1 week later to complete the restoration.

When the patient returned, a dentin substitute (Biodentine^®, Septodont) was placed onto the SDF treated occlusal surfaces of tooth No. 19 (Figure 4). This dentin substitute material is a calcium silicate cement that stimulates secondary dentin formation. It is composed of a powder, which consists of tricalcium silicate, calcium carbonate, dicalcium silicate, calcium oxide, and iron oxide, and a liquid, which consists of hydrosoluble polymers and calcium chloride, that are mixed together to form a gel-like material.⁴ Upon mixing these components, the calcium silicate particles react with water to yield calcium, hydroxyl, and silicate ions.⁴ The resulting calcium hydroxide increases the pH to 12, while the calcium silicate hydrate gels polymerize over time to form a solid structure.⁴

While placing the dentin substitute, the presence of caries was noted on the occlusal surfaces of tooth K (Figure 5). After the dentin substitute was properly packed over the SDF treated surfaces of tooth No. 19, the caries on tooth K was removed with hand instruments, and stainless steel crowns were cemented over both teeth (Figure 6). Overlying materials (eg, composite, amalgam, stainless steel crowns, resin-modified glass ionomers), don't affect the dentin substitute's final set.⁵

The ideal characteristics of SDF and the biocompatibility of the dentin substitute are fundamental to the overall success of the silver modified interim therapeutic restorative technique. Beyond providing an excellent minimally invasive restoration that arrests the development of caries, because the technique doesn't involve high-speed instrumentation, it is particularly desirable during the COVID-19 pandemic, when the dental profession is attempting to minimize the use of aerosols as much as possible.

Juan F. Yepes, DDS, MD, MPH, MS, DrPH
Diplomate
American Board of Pediatric Dentistry
Professor
Department of Pediatric Dentistry
Indiana University
School of Dentistry
Indianapolis, Indiana
Private Practice