Retention Rate of Flowable Composite in Demenerlized Pits and Fissure Clinical Trial
Official title:
Retention Rate of Hydroxyapatite Nano-Fiber Reinforced Flowable Composite Versus Conventional Resin-Based Flowable Composite in Initially Demineralized Pits and Fissure: A One Year, Randomized Clinical Trial
Pits and fissures have been considered as the single most important feature leading to the development of occlusal caries; About 90 % of carious lesions are found in the pits and fissures of permanent posterior teeth .Several materials and techniques have been developed to enhance the longevity of pit-and-fissure sealants, including the use of flowable composite resins as pit-and-fissure sealants
Pits and fissures have been considered as the single most important feature leading to the
development of occlusal caries; About 90 % of carious lesions are found in the pits and
fissures of permanent posterior teeth . The complex morphology of occlusal pits and fissures
makes them an ideal site for retention of bacteria and food remnants, rendering the
performance of proper hygiene difficult or even impossible .
Several materials and techniques have been developed to enhance the longevity of
pit-and-fissure sealants, including the use of flowable composite resins as pit-and-fissure
sealants . However, the clinical longevity of flowable composite as fissure sealants is
directly related to their retention, where the percentage of rate of retention differ on a
12-month follow-up examination were the partial loss rate of flowable composite material
ranges from 15.5% to 16.5% and total loss were ranged from 12.7% to 13%, while on a 24-month
follow-up examination the partial loss rate ranged from 18.1% to 20% and total loss rate
ranged from 15.6% to 17%, and that depends on morphology of pits and fissures, adequate
isolation, conditioning of enamel, application techniques, particular material
characteristics like viscosity, surface tension, adequate adhesion and penetration of the
material into the previously etched system of fissures.
In order to overcome the shortcomings of traditional dental composites, nanofibers or
nanotubes fillers are broadly used in the academia and industry. The type of Nanofibers and
Nanotubes used to reinforce dental resin composites include polymeric nanofibers, metallic
nanofibers, and inorganic hydroxyapatide (HAP) nanofibers. The Hydroxyapatite Nanofibers are
calcium phosphates fillers that allow the release of mineral from dental resin composite.
Also HAP nanofibers possessing sufficiently high slenderness ratios and relatively long and
thin structure, and create a lot of bonding points in the interface with polymeric matrix.
When the composites suffer from huge pressure this allow tremendous stress transfer from weak
polymeric matrix to tough HAP nanofibers; and consequently increase the mechanical properties
of resin composite. So this study will examine the effect of adding HAP nanofibers on the
clinical performances and retention rate of flowable resin composite.
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