الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 179 |  |  |
| | | from | 179 | | |
Abstract
Due to the complex morphology of occlusal pit and fissures, these surfaces are highly caries susceptible. This is especially true for erupting teeth that are in the maturation process and anatomic characteristics cause difficulty in access for cleansing procedures and further incomplete enamel maturation adds to caries susceptibility.
Pit and fissure sealants has proved to be an effective method in reducing the rate of occlusal caries on permanent posterior teeth by forming a barrier between the tooth surface and the oral environment. Most of the sealant materials used today are resin-based materials that possess high retention rates, but are clinically limited by the difficulties inherent in the use of resins in a moist environment because they are Bis-GMA based materials, which are primarily hydrophobic in nature and require a dry field.
Glass ionomers are less sensitive to moisture than resins, a fact that makes it reasonable to believe that they may be preferable for sealing newly erupted teeth. they are used for sealing pits and fissures, mainly due to their fluoride release and adherence to the dental structures. Despite their promising results, the main disadvantage of glass ionomer sealants is its inadequate retention. Hence, a moisture-tolerant resin sealant is necessary to ensure optimal retention.
Subsequently, this study aimed to evaluate and compare the moisture-tolerant resin-based sealant that contains no BisGMA (Embrace™ Wetbond™ Sealant) with conventional resin-based sealant that contains BisGMA with (Clinpro™ Sealant) and Glass Ionomer sealant (GC Fuji Triage) for bond strength, microleakage in vitro and clinical performance at periodic intervals.
The current study was based on 2 main parts, in the first, (in vitro) part of the study, shear bond strength and microleakage were evaluated. A total of 42 extracted sound permanent molars were assigned to 3 groups: group 1: conventional resin-based Clinpro sealant, group 2 glass ionomer Fuji Triage sealant, group 3: moisture tolerant Embrace Wetbond sealant. After specimen preparation, the shear bond strength was determined with a universal testing machine. An additional 42 molars were used for microleakage assessment. The fissure pattern was sealed in strict accordance with the manufacturers’ instructions. After thermocycling, the dye penetration was examined.
In the second part of the study, total of 75 first permanent molars in healthy cooperative children aged between 6-9 years included in this clinical trial. Children were enrolled from the Pediatric Dentistry and Dental Public Health Department clinic, Faculty of Dentistry, Ain Shams University. Subjects were recruited according to certain inclusion criteria and a written consent was signed by their parents before conducting the study. The 75 molar teeth were randomly divided into three groups according to the material used as follow: group 1(active control): consisted of 25 molar teeth that sealed with conventional hydrophobic resin based sealant (clinpro). group 2: consisted of 25 teeth that sealed with glass ionomer sealant (Fuji triage). group 3 consisted of 25 teeth that sealed with moisture tolerant hydrophilic sealant (embrace wetbond sealant). Evaluation of sealant retention and development of caries was performed at 3 and 6 months using Modified Simonsen’s criteria.
Bond strength testing showed that group (III) Embrace Wetbond (moisture tolerant resin based sealant) was found to have the highest shear bond strength (17.63±2.09) among the three groups, followed by group (I) Clinpro (conventional resin based sealant) (12.93±1.04), while group (II) Fuji Triage (glass ionomer based sealant) (7.82±1.32) was found to have the lowest shear bond strength value. The difference between the three groups was found to statistically significant (p<0.001). Regarding microleakage; there was no statistical significance difference between the microleakage score of group (I) Clinpro (conventional resin based sealant) (0.57±0.94) and group (II) Fuji Triage (glass ionomer based sealant) (0.14±0.36) and there was no statistical significance difference between microleakage scores of Clinpro and Embrace sealants. The highest microleakage score was found in group (III) Embrace Wetbond and it was significantly higher than microleakage score of group (II).
Clinically, the 3rd month clinical evaluation showed complete retention in 68% of conventional resin-based sealant, 82% of moisture-tolerant resin-based sealant, and 32% of glass ionomer sealant. At 6 months’ evaluation, complete retention was seen in 56.5% of conventional resin-based sealant, 72.7% of moisture-tolerant resin-based sealant, and 22.7% of glass ionomer sealant. Development of caries was seen in 1 tooth (4.3%) of groups 1-3 and 2 teeth (9.1%) in group 2 at the 6-month follow-up. These results showed no significant difference between moisture-tolerant resin-based sealants and conventional resin-based sealants in both retention and development of caries and it also showed that moisture-tolerant resin-based sealants had better performance than glass ionomer sealant. Thus, it indicates that moisture-tolerant resin-based sealant could be considered as a gain to pit and fissure sealants in Pediatric Dentistry.