Performance of a Conventional Sealant and a Flowable Composite on Minimally Invasive Prepared Fissures
Howard E. Strassler, DMD
Francescut P, Lussi A. Oper Dent. 2006;31(5):543-550.
Three different fissure preparation procedures were tested and compared to the non-invasive approach using a conventional unfilled sealant and a flowable composite. Eighty permanent molars were selected and divided into 4 groups of 20 teeth each. All the teeth were split into 2 halves, and the exposed fissures were photographed under a microscope (35x) before and after being prepared using the following methods: (I) Er:YAG laser (KEY Laser, KaVo) 600 mJ pulse energy, 6 Hz; (II) diamond bur; (III) Er: YAG laser (KEY Laser, KaVo) 200 mJ pulse energy, 4 Hz; (IV) Control group: Powder jet cleaner (Prophyflex, KaVo, Germany). The pre- and post- images were superimposed in order to evaluate the amount of hard tissue removed. Ten teeth in each group were then acid etched and sealed with an unfilled sealant (Delton opaque, Dentsply), while the remaining 10 teeth were acid-etched, primed and bonded (Prime and Bond NT, Dentsply) and sealed with a flowable composite (X-flow, DeTrey, Dentsply). Material penetration and microleakage were evaluated after thermocycling (5000 cycles) and staining with methylene blue 5%. ANOVA and Mann-Whitney tests were applied for statistical analysis. The laser 600 mJ and bur eliminated the greatest amount of hard tissue. The control teeth presented with the least microleakage when sealed with Delton or X-flow. A correlation between material penetration and microleakage could not be statistically confirmed. Mechanical preparation prior to fissure sealing did not enhance the final performance of the sealant.
The use of invasive preparation of pits and fissures has been predicated on the need to remove the smear plug and debris that is present in pits and fissures. You, or your hygienist, decide that a patient (usually a child or adolescent) would benefit from a sealant on a susceptible pit and fissure. You make the decision after the oral prophylaxis is complete. If you believe that better retention and, hence, prevention of caries in pits and fissures can be achieved by using invasive procedures, then you must sit down and “surgically prepare” the tooth before sealant application. This increases the time, use of materials and devices, and the need for intervention by the dentist, all of which collaborate to increase the fee.
The authors of this research paper evaluated several different techniques to compare invasive and noninvasive clinical approaches to sealant placement. The techniques they used included laser tooth preparation, using a diamond bur, and merely cleaning the occlusal surface with an air-abrasion powder cleaner. Their findings indicated that preparation before sealing the fissure did not enhance the performance of the sealant. Based on this research, dental auxiliaries can place sealants without the need for the pit and fissure to be surgically prepared. This study also evaluated the parameters of tooth preparation when providing a recommendation. Good, sound clinical practices when placing a sealant are also important. The field must be isolated to avoid any contamination of the surface during sealant placement, and the sealant must be placed with an appropriate thickness (0.3 mm) so that it will be retained over a longer period of time. Once a sealant is placed, it must be reevaluated at each recall and, if defective, be repaired or replaced.
Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland