Preventing Caries in Partially Erupted Molars

Glass-ionomer sealants provide a superior alternative to resin sealants

Jeanette MacLean, DDS

Pediatric dentists are often presented with the clinically challenging task of managing partially erupted molars. In children and adolescents, permanent molars sometimes begin to erupt before the mandible has developed adequate arch length to fully accommodate them. Instead of fully erupting in a few weeks, these partially erupted molars can remain under an operculum for months or even years. The presence of deep, fissured grooves combined with a food trapping operculum can become a recipe for a cavity disaster.

In the past, oral hygiene instruction and fluoride varnish were the only suitable tools available for caries prevention in this clinical scenario. Placement of a resin sealant was simply not appropriate because a partially erupted molar cannot be properly isolated. Therefore, it was very frustrating to see that sometimes these teeth would develop occlusal caries before they had fully erupted. Even more frustrating, from time to time, I encounter patients who have had resin sealant applied to their partially erupted molars at other offices or sealant clinics, and there is extensive caries underneath the material. The hydrophobic resin permits microleakage at the margins and essentially acts as a trap for food and plaque. Because poor isolation and a poor resin bond can actually contribute to the development of caries rather than preventing it, a bad sealant is worse than no sealant at all.

The introduction of glass-ionomer sealants offers a preferable option for the treatment of partially erupted molars. Although there are many benefits to using glass-ionomer sealants, they are especially superior to resin sealants for partially erupted molars because they are hydrophilic and can be placed on moist surfaces. Glass-ionomer sealants also release fluoride, inhibit biofilm formation, and help prevent decay from acid and bacteria. Furthermore, the use of a 20% polyacrylic acid surface conditioner can improve chelation and enhance the chemical bond between the glass and the enamel via ion exchange. Best of all, the caries prevention benefits of glass-ionomer sealants are not fully dependent on retention of the material. Small particles remain in the fissures of treated teeth, acting as a fluoride reservoir and enhancing the remineralization of nearby enamel. Conversely, the loss of retention of resin-based sealants has been associated with the risk of developing caries.

Case Report

An 11-year-old female patient presented with partially erupted mandibular second permanent molars and a history of high caries risk (Figure 1). First, the teeth were cleaned with plain pumice (Figure 2). A 20% polyacrylic acid surface conditioner (Cavity Conditioner, GC America) (Figure 3) was then applied for 10 seconds with a microbrush (Figure 4) and rinsed (Figure 5). Next, a low-viscosity glass-ionomer sealant (GC Fuji TRIAGE^® EP [Pink], GC America) (Figure 6) was activated and mixed for 10 seconds in a capsule mixer (Figure 7). This glass-ionomer sealant was selected because of its pink color indicator and ability to be command set with a curing light, which helps to keep the material in place while it continues to fully auto-cure and prevents it from washing away in saliva. In addition, the material incorporates a casein phosphopeptide-amorphous calcium phosphate ingredient that provides enhanced protection by releasing calcium and phosphate ions. Once the glass-ionomer sealant was mixed, it was immediately applied to the fissures of the left-side mandibular second permanent molar using a capsule applicator (Figure 8). A damp microbrush was then used to adapt the material to the tooth (Figure 9), and it was allowed to auto-cure for 2.5 minutes. After curing, the procedure was repeated for the contralateral molar (Figure 10). The glass-ionomer sealant will protect the molars as they continue to erupt, and its pink color indicator will reveal if/when more material could be added over time.

About the Author

Jeanette MacLean, DDS
Diplomate
American Board of Pediatric Dentistry
Affiliated Children's Dental Specialists
Glendale, Arizona