December 11, 2018
by Fay Goldstep, DDS, FIADFE, FASDA; Cathy Delios, RDH
Occlusal decay and its consequences have a major impact on the dental health of our patients. It is the single most common chronic childhood disease world-wide 1 and its results affect our patients throughout their lives. Molars and premolars are vulnerable, especially during their eruption phase. Deep pits and fissures provide an ideal environment for bacteria to thrive, digesting carbohydrates and creating acids. This leads to the demineralization of susceptible immature dental surfaces.
Why Place Pit and Fissure Sealants
The most efficient way to prevent pit and fissure caries is through the sealing of the vulnerable tooth surfaces, from the cariogenic bacteria and fermentable carbohydrate substrates left on the teeth during mastication. This is best achieved by placing a physical barrier in the form of a seal on the pits and fissures. 2
Dentists have been attempting to find conservative, minimally invasive ways to treat pit and fissure areas for many years. In 1955, Michael Buonocore suggested that it would be possible to prevent caries by sealing pits and fissures with a bonded resin material. The appropriate materials became available only later, and he published a further paper on the use of pit and fissure sealants in 1967. 3
The first permanent molars are a cornerstone in the development of the adult dentition. They often erupt before the patient and/or the parent is even aware their existence. The partially erupted permanent first molar is very difficult to keep caries-free during its eruption phase. It requires between 12 and 18 months to fully erupt into occlusion with the existing teeth in the arch. 4 (Bicuspids only need three to six months to reach full occlusal height). The reduced height of the first molar for this prolonged period means that it is usually below the reach of the patient’s toothbrush unless a major effort is made by the patient to achieve contact. This is not likely in a young child. Hence the occlusal surface of the first permanent molar is rarely brushed and is often covered with plaque and food debris in a low pH environment. 5 This is further exacerbated if the tooth remains under an operculum for a long period of time. These factors lead to an erupting tooth that can easily become carious on its occlusal surface by the time it fully erupts. 5
What Materials to Use
The objectives for the pit and fissure sealant material are: to seal the area, to make the tooth surface caries resistant and to be easy to use. 6 Evidence regarding the efficacy of sealants in reducing occlusal caries is well established. 7 Composite resin is the most commonly used sealant material. It seals the pits and fissures through micro mechanical means. Micro mechanical retention is created through tags after enamel etching. However, these tags are easily destroyed by contamination with saliva and this leads to the eventual failure of the resin sealant. 8 Glass ionomer (GI) sealant material is hydrophilic and hence not as moisture sensitive as hydrophobic resin material and it offers an alternative treatment for the wet conditions in the oral cavity. 9
Resin sealants have a higher retention to pits and fissures than GI sealants. However, resin-based sealants have been shown to lose almost all of their protective effect once retention is lost. 10,11 In contrast to resin, even when the GI sealant appears clinically as partially or totally lost, small amounts of the material remain. The GI material stays within the depths of the fissure since it bonds chemically to the tooth and consequently the sealing effect continues. 6 This remaining material provides a barrier to the bacteria and also promotes remineralization through the release of fluoride. 10,11
Most studies have used ‘retention of the sealant’ as the end point for fissure sealant effectiveness. In addition, many studies have assumed that only a totally intact sealant (as opposed to a lost or partially retained sealant) is the criterion for effective caries prevention and clinical success. 12 But systematic reviews have not found that the sealant retention rate is a valid predictor of clinical outcomes. 12 Hence it should not be used to measure sealant success in preventing caries.
Two systematic reviews 10,11 found that neither resin nor GI sealants were superior in the prevention of dental caries in children. Therefore, the choice of which material to use may have more to do with ease of use, moisture control, and patient compliance. 13
Hydrophobic resin sealants do not provide the best solution for sealing permanent first molars since they are only partially erupted for a prolonged period of time and adequate isolation is not attainable. 5 Moreover, it has been shown that improperly placed resin sealants can leak and allow caries to develop unnoticed under the leaking sealant. 14 This is a reason why many dentists have stopped using resin fissure sealants: too many surprises when opening up carious lesions under failed resin sealants, and finding very extensive decay that has been left undisturbed for a prolonged period of time.
Resin sealants also cover the immature undermineralized tooth surface, not allowing fluoride, calcium, phosphate and other minerals from the saliva to contact the tooth surface and mineralize it. 5 Enamel requires almost 3 years to reach full mature mineralization. During this time the enamel is incompletely formed and more susceptible to demineralization under low pH. 15
Advantages of Glass Ionomer Fissure Sealants
Glass ionomer fissure sealants offer several major advantages over resin sealants especially in partially erupted teeth. A summary follows: 5
A young patient presented at his six-month recare appointment with erupting first permanent molars in all quadrants. In view of the child’s history of decay and deep pits and fissures on the occlusal surfaces, all the erupting teeth were sealed with self curing glass ionomer fissure sealants.
GC Fuji Triage, white shade (GC America, http://www.gcamerica.com) was applied on the lower molars and Riva Protect, pink shade (SDI Australia, https://www.sdi.com.au) was applied on the upper molars. (Different materials were used in this case to illustrate the technique for this article and for further educational purposes. Both materials come in white and pink shades).
Procedure (Figs. 1 & 2)
Fig. 1 A-J
An erupting mandibular first molar is sealed with Fuji TRIAGE (white) (GC America)
Fig. 2 A-G
An erupting maxillary first molar is sealed with Riva Protect (pink) (SDI Australia)
Fissure sealant application is an excellent proactive dental treatment. It is an underused treatment because of the difficulties in isolation with resin sealants and the unwelcome surprises of advanced decay that is sometimes found under failed resin sealants. Glass ionomer sealants offer the advantages of easier isolation and the ionic exchange of fluoride and other minerals to help in the mineralization of the immature tooth surface. It is time to bring fissure sealants back out, as proactive intervention treatments for our young patients, this time with patient friendly glass ionomer materials. OH
Oral Health welcomes this original article.
About the Authors
Dr. Fay Goldstep has lectured nationally and internationally on Proactive/Minimal Intervention Dentistry, Soft-Tissue Lasers, Electronic Caries Detection, Healing Dentistry and Innovations in Hygiene. She has been a contributing author to four textbooks and has published more than 100 articles. She sits on the editorial board of Oral Health. Dentistry Today has listed her as one of the leaders in continuing education since 2002. Dr. Goldstep is a consultant to a number of dental companies, and maintains a private practice in Richmond Hill, Ontario. She can be reached at email@example.com.
Cathy Delios graduated from Georgian College in 2000 and has been in private practice for the last 18 years. She is very interested in nutrition and overall health and wellness, which provides endless learning opportunities. Cathy is an avid reader and sports fan and loves to exercise when she is not busy with her husband and two active sons.