Sarkar N. Corrosive-Wear and Related Properties of ICE and ROKLSU School of Dentistry, 1100 Florida Avenue, New Orleans, LA 70119.

The aim of this study was to evaluate the resistance to corrosive wear of ICE and ROK and data were compared those of three popular brands, POINT 4 (Kerr-Sybron), Esthet (Caulk) and Supreme (3M/Espe). The corrosive wear had been simulated in two steps:
A. CORROSION – Samples were exposed to 0.1 N NaOH (Sodium hydroxide) solution enriched with OH- at 60oC for two weeks. They were then washed and dried at 60oC. Each was measured for (i) Mass-loss (gravimetrically) (ii) Si-loss (ICP-AE) and (iii) Degradation depth (microscopically). The degrade surface of each brand was also characterised by scanning electron microscopy (SEM).

B. WEAR – Test composites were filled into ceramic discs and polished to a flat surface. Samples were then corroded as above. Corroded specimens were abraded in a tooth-brushing machine. The wear depth was measured relative to the ceramic disc.





Mass Loss (%)

Si-loss (ppm)

Degradation (µm)

Abrasive Wear (Control) (µm/hr)

Corrosive Wear (Degraded) (µm/hr)

ICE 1.83 + 0.21 409 + 5 42 + 2 76 + 6 182 + 22
ROK 2.63 + 0.19 19 341 + 45 62 + 4 70 + 4 191 + 16
POINT 4 1.91 + 0.05 N/A 63 + 5 146 + 15 184 + 26
ESTHET 1.48 + 0.03 N/A 13.5 + 0.7 79 + 17 178 + 9
SUPREME 9.36 + 0.15 1885 + 66 195 + 11 72 + 9 399 + 31


It is apparent from the above table that different brands exhibit different degrees of resistance to corrosion and wear. SEM examination of ICE’s degraded surface revealed a matrix that is unattacked during corrosion exposure. Similar degradation features were seen on the surface of ROK, POINT 4 and Esthet. In contrast, degraded Supreme surface exhibited the presence of interpenetrating cracks and debonding at the filler-matrix interface.

From the results, it is expected that ICE and Rok will perform as well as, if not better than, Point 4 and Esthet in a clinical situation.


Rok, The Dental Advisor, Volume 21, 2004.

Rok is a light-cured, radiopaque, hybrid composite for use in direct posterior restorations. The material is designed to have a high compressive strength and filler level, while maintaining low polymerisation shrinkage.

The packable nature of Rok was rated very good, enhancing firm interproximal contacts. The composite is not sticky, but slightly dry, making the syringe material difficult to transfer from the pad to the tooth. Several consultants noted that before curing, the composite appeared to not blend with the tooth, but following light curing, shade blending with the tooth was rated very good – a four stars rating.


Seabra B.G.M., Seabra F.R.G.; Machado C.T., Oertli, D.C.B.;Braz, R.; Abreu A.D.J; Performance of two different types of light units on the composed resin cure depth; Abstract #0102, 1st Meeting of Latin Federation, 2005.

The difficulty in getting a composed resin with good mechanical properties must, in part, to its depth of polymerization, being necessary to know the source of used light and its capacity to polymerize. Of this form, the objective of this study was to evaluate the Vicker hardness of two composite in relation to the uniformity polymerization. Two light curing devices had been used, one of halogen light, Ultralux, and a LED, the Radii. Five samples had been prepared for each light unit and hybrid composed resin, Rok and Glacier (SDI), using cylindrical PVC matrix (4 mm of diameter and 2 mm of depth). All the samples had been light-cured by 20 s, following the instructions of the manufacturer. The samples had been stored in exempt containers of light for 24 h. The hardness was measured in two depths (top and 2 mm) with three impressions for each depth. The Vickers microhardness test (Shimadzu) was carried out under a 300g load for 15 s. The data had been analyzed by “ t” test. To the composed resin Glacier, used as control, this it did not present statistically significant differences in the top hardness (60,04 ± 2,75, Radii and 58,26 ± 3,24, Ultralux), as well as for the hardness at 2mm (50,58 ± 2,38, Radii and 46,84 ± 3,44, Ultralux). However, had statistically significant differences when comparing these data, in relation to the hardness of top and 2mm depth, for both devices (p< 0,01). For the Rok composite, it did not significant difference statistic in the top hardness (82,2 ± 1,46, Radii and 79,44 ± 3,47, Ultralux), as well as for the hardness at 2mm (63,9 ± 2,39, Radii and 73,22 ± 2,47, Ultralux), but, it had statistically significant differences when comparing these data, in relation to the hardness of top and 2mm, for both the devices (p= 0,01). These results indicate that not having uniformity of polymerization to the depth of 2mm for two composed resins tested and between the two devices light-curing units, however, Rok composite resin presented better resulted that the Glacier composed resin, in the evaluated situations. Key-words: composite resin, photopolymerization.


de Araujo Silva Gusmao G. Mario et al; The influence of storage time and pH variation on water sorption by different composite; p60-65, Indian Journal of Dental Research, 24(1) 2013,Ferderal University of Pernambuco, Brazil.

Aim: To assess the influence of storage time and pH cycling on water sorption by difeerent composite resins.

Materials: Nine resin brands were selected and divided into groups: G1- Rok (SDI), G2-Ice (SDI), G3-Glacier (SDI), G4-Z350 (3M/Espe), G6-TPH 3 (Dentsply), G7-Suprafill (SS White) and G9-Masterfill (Biodinamics)to particpate in the study.

Results: Overall Rok has very low water absorption when compared to competitor brands such as Z350 (3M/Espe), Z250 (3M/Espe), Suprafill (SS White).


Ferooz M, Basri F, Negahdari K, Bagheri R; Frecture Toughness Evaluation of Hybrid and Nano-hybrid Resin Composites after Ageing under Acidic Environment; Journal of Dental Biomaterials, 2015;2(1), Shiraz University.

Aim: To compare the fracture toughness (KIC two types of resin composites under tensile loading and to assess the effect of distilled water and latic acid on the resistance of the restoratives to fracture after three months of immersion.

The results of two-way ANOVA did not show a significant combined effect of material, time, and storage medium on fracture toughness (p=0.056). However, there was a strong interaction between materials and time ((p=0.001) when the storage medium were ignored. After 24h of immersion in distilled water, Paradigm revealed the highest Klc values followed by Rok, Luna and Estelite. Immersion in either distilled water or lactic acid significantly decreased the fracture toughness of almost all materials as time interval increase


As time increased, Klc significantly decreased for almost all resin composites except for LUNA which showed a slight decrease after one month of immersion in distilled water. Rok came out on top after 3 month of exposure to lactic acid!