Fluoride release, weight loss and erosive wear of modern aesthetic restoratives

Abstract

265 RESEARCHrestorative dentistry limited the scope of conventional GICs in clinical application. More recently-introduced resin ionomers have less water sensitivity, and improved aesthetic and mechanical properties. 11 However, there are great differences between various materials in the levels of fluoride released, 12 and there is also less fluoride released when artificial 13 and human saliva 14 are used, rather than deionised water. Some materials claimed by their manufacturers to release fluoride hardly do so in measurable quantities. 15 In fact, a variety of such fluoride-releasing materials are primarily resin-composite systems with some form of fluoride incorporated into the resin matrix. 16 Most of these materials have a lower level of fluoride release than GICs, and their clinical effectiveness is also unknown.Therefore, the objectives of this study were to investigate the long-term levels of fluoride released from selected GICs and resin ionomers, and the effects of acidulated phosphate fluoride (APF) gel on the levels of fluoride released and on the physical structure of the glass ionomer cements, by monitoring their weights and surface changes. Materials and methods Restorative materialsThe details of the materials investigated in the present study are listed in Table 1. ChemFil Superior was the positive control and Z100 was the negative control. Specimen preparation and immersionFive specimens of each material were prepared according to the manufacturers' instructions and placed into disposable, cylindrical Teflon moulds (3.0 mm diameter × 2.7 mm height), 17 and then pressed between two Mylar-covered glass slides. The resin ionomer cements were light cured from both ends of the moulds for 40 seconds using a VCL 200 visible light unit (Demetron Research Corporation, Danbury, CT, USA). They were allowed to set for about an hour. After setting, each specimen was removed from its mould, weighed by an electronic balance, then placed in a polypropylene vial with 2 mL of artificial saliva (0.05 M acetate buffer with 2.2 mM CaHPO 4 adjusted with glacial acetic acid to pH 5.0) and stored at 37°C. The solution was replaced at 6 hours, 1 day and 2 days, then weekly for 12 weeks. The amount of fluoride released was also measured at these same times for the first 5 weeks, then at 8 weeks and 12 weeks. Each specimen was dabbed dry before weighing at the times of solution replacement. Determination of fluorideOne mL of the solution was mixed with 0.1 mL of TISAB III solution and the fluoride concentration was measured with a specific fluoride electrode (Orion 9609BN electrode: Orion Research Incorporated, Boston, MA, USA) and read in millivolts. Calibration of the fluoride electrode was done before each measurement session Objective In this investigation, the in vitro sustained fluoride release, weight loss and erosive wear of three conventional glass ionomer cements (Fuji IX, ChemFil Superior, Ketac-Silver), three resin-modified glass ionomer cements (Fuji II LC, Vitremer, Photac-Fil), a polyacid-modified resin ...

Effect of prolonged erosive pH cycling on different restorative materials

“…It is known that during consumption, food or drink contact only shortly with the tooth surfaces before they are washed away by saliva. However, in previous studies, substrates usually contacted acidic foodstuffs for a prolonged period of time or did not account for the role of saliva (11–17). The present study was designed to overlap the above‐mentioned limitation of in vitr o studies, by employing a dynamic erosive pH‐cycling model.…”

“…Various assessment techniques have been applied to evaluate the degradation of dental materials and the loss of dental hard tissue by erosive challenges, such as microhardness (11, 13, 14, 20, 21), surface roughness (21, 22), weight changes (15), compressive, biaxial flexure and shear punch strength (12, 16) and wear (15, 17). Initially, the aim of this study was to assess the effect of an erosive pH cycling on different restorative materials and also on the enamel adjacent to these materials.…”

Effect of different topical fluoride applications on the surface roughness of a colored compomer

“…According to Turssi, et al 25 , based on the erratic behavior pattern shown by Photac-Fil as a result of NNaF gel and APF gel treatment, degradation depends not only on the pH of the gel, but probably also on the gel’s ability to form a complex structure with the metal ions of the restorative material. Yip, et al 30 suggested that Ra values of the Photac-Fill were comparable to the conventional GICs, and according to these investigators it is possible that stresses built up in the glass particle-resin matrix interfaces. Hadley, et al 13 and Billington, et al 1 demonstrated that immersion of Photac-Fil in 0.02% NNaF solution for 24 h results in surface roughening of about 310-370%.…”

“…Previous studies have shown that topical fluoride application to compomers could increase the surface roughness of this materials 3,7,30 -32. The clinical significance of the increased surface of the materials covers the increased plaque adhesion and its harmful effects on the tooth and periodontium, to surface discoloration and fatigue failure 2-3,12,19,22,29 .…”

Comparative evaluation of fluoride release and recharge potential of novel and traditional fluoride-releasing restorative materials: An in vitro study

“…Glass ionomer cement (GIC) is considered to be a fluoride reservoir which maintains a steady flow of fluoride ions into the surrounding tooth structure, thus enhancing the resistance to secondary caries. [ 1 2 ] However, inadequacy of conventional GIC to be used in stress-bearing area has led to the development of newer fluoride-releasing materials with better physical properties.…”