Effect of surface penetrating sealant on surface texture and microhardness of composite resins

Abstract

The application of Fortify (Bisco, Lombard, IL), an unfilled resin, to the surface of composite resin restorations is intended to fill in defects in the surface that persist despite polishing, improve marginal integrity, and increase these materials' resistance to abrasion. The aim of this study was to observe the surface texture by scanning electron microscopy and measure the microhardness of the surface. For each sample of composite resin covered with glaze, 40 measurements were made of the thickness of the resin. Measurements of the Vickers microhardness included three samples of composite resin, three samples of glaze, and six samples of composite resin covered with glaze. A relationship was established between microhardness and thickness. Scanning electron microscopy showed a noticeable improvement in the surface texture. Nevertheless, areas were seen in which glaze seemed very thin or even completely absent. Measurements of the thickness ranged from 0-70 microm. The mean microhardness of composite resin was 65.8 +/- 0.7, while the mean hardness of glaze was 7.3 +/- 0.7. The microhardness of the double layer was reduced, depending on the thickness of the glazing resin. The capacity of glaze to mask surface defects of composite resin was shown, but it was difficult to obtain a regular surface with liquid resin. The application of this product caused a decrease of the microhardness of the composite resin's surface.

Relation between in-vitro wear and nanomechanical properties of commercial light-cured dental composites coated with surface sealants

“…It is important to stress that this is not necessarily the case of conventional microhardness tests, where much higher loads (in the range of 10 to 100 g) may be employed and much deeper depths may be reached, increasing the influence of the resin substrate on the measurements. Nevertheless, the present findings are in qualitative agreement with those from Bertrand et al 11 and Catelan et al 19 , where the application of a surface penetrating sealant reduced the microhardness values of the resin composites.…”

“…The obtained elastic modulus (E) values as a function of contact depth for the Z250 composite resin and the four 11,20 . It is interesting to note that among the tested sealants the only one that incorporates inorganic silica particles in its composition is the one which presents the smallest values of both hardness and elastic modulus.…”

“…Generally, dental sealants present low viscosity and surface energy, being able to penetrate, fill in and cover surface defects and, therefore, improve the resin surface by filling the microfissures and small irregularities usually presented in such composites. Further, they improve marginal integrity, reduce microleakage, decrease surface roughness and increase wear resistance [8][9][10][11][12][13] . Beun et al (2012) 14 have shown that resin-based pit and fissures sealants commercially available are effective on preventing pit and fissures.…”

“…On the other hand, if fissures need to be enlarged, flowable resin composites would be more adequate 14 . Although surface sealants do increase wear resistance of dental composites, the samples filled with surface sealants present reduced surface hardness 11 . This observation is opposite to the common-sense direct correlation between hardness and resistance to abrasive wear.…”

Influence of the Surface roughness on translucency and surface color of the dental composite resins

“…하지만 이 방법도 복합 레진에 한정 해 적용되며 자가 중합형 혹은 광중합형 글래스 아이오노머 시멘트나 컴포머와 같이 복합레진에 비해 표면 연마가 어려 운 다른 심미수복 재료에는 matrix strip의 적절한 응용이 나 다른 연마 방법의 모색이 더 필요할 것이다 [27][28][29][30][31] . 이외에 도 penetrating sealant를 표면에 도포하여 활택을 증진 시키는 방법 32) 에 대한 연구, finishing이나 polishing시 표 면이나 직하방의 기질적 변화 33) 에 대한 연구, 칫솔질이나 polishing 시 표면 거칠기나 광택의 변화 [34][35][36] …”