Water sorption and water solubility of current luting cements: an in vitro study.

OBJECTIVE: To evaluate the water-sorption characteristics and the solubility behavior of 4 luting cements-2 composite resins (CRs), a polyacid-modified composite resin (PMCR), and a resin-modified glass-ionomer cement (RMGIC)-according to the ISO 4049 specifications. METHOD AND MATERIALS: Five disks (15 x 1 mm) of each material (Variolink II [CR1; Vivadent], Panavia F [CR2; Kuraray], Resinomer [PMCR; Bisco], and Fuji Plus [RMGIC; GC]) were prepared according to the manufacturers' instructions. Specimens were first desiccated until a consistent mass was obtained. Specimens were immersed for 7 days in distilled water and immediately weighed after this period. Then the disks were post-desiccated and weighed every day for 35 days. The water sorption and solubility of each specimen were calculated according to the change in its weight as observed before and after immersion and desiccation periods. RESULTS: Fuji Plus exhibited the overall higher values of water sorption and solubility (P < .001). Of the 3 resin-based luting cements, Resinomer demonstrated significantly higher water sorption and solubility (P < .001), whereas Variolink II and Panavia F showed low values and were not significantly different (P = .2). CONCLUSIONS: Behavior of resin-based materials in water varies according to the composition characteristics. In particular, the high portion of hydrophilic chemical species, as well as the filler characteristics, provoke very high water sorption and solubility values. In this way, and within the limitations of this in vitro study, composite resin luting cements appear to be more suitable than compomers and resin-modified glass-ionomer cements to meet longevity requirements.

Influence of initial water content on the subsequent water sorption and solubility behavior in restorative polymers.

PURPOSE: To evaluate the water sorption characteristics and solubility behavior of two resin-based composites, an ormocer, a compomer and a resin-modified glass-ionomer, according to ISO 4049 specifications and also without the initial desiccation cycle. METHODS: After polymerization, five disks (15 x 1 mm) of each material [Filtek P60 (P60), Solitaire 2 (SOL2), Admira (ADM), Compoglass F (COF) and Fuji II LC (FLC)] were desiccated until a constant mass (ml) was obtained. They were immersed in distilled water for 7 days and immediately weighed after that period (mass m2). Then disks were again desiccated and weighed every day for 35 days (mass m3). Sorption and solubility values were deduced from these different measures. Without initial desiccation mass m1 was obtained just after polymerization. RESULTS: Without initial desiccation, all the materials absorbed less water and solubility was 1.5 to 8 times greater than in standard experiment. For the two protocols, water sorption and solubility were significantly greater in FLC, and ADM showed the least weight loss of all the materials tested.

In vitro evaluation of microleakage of indirect composite inlays cemented with four luting agents.

STATEMENT OF PROBLEM: Microleakage around dental restorations is implicated in the occurrence of secondary carious lesions, adverse pulpal response, and reduced restoration longevity. PURPOSE: The aim of this in vitro study was to evaluate the microleakage of indirect resin composite inlays cemented with 4 luting agents. MATERIAL AND METHODS: Standardized Class V inlay preparations overlapping the cemento-enamel junction were prepared on the buccal and lingual surfaces of 40 extracted human mandibular third molars. Eighty postpolymerized, heat-treated resin composite inlays (Targis, 72 specimens, 8 controls) were processed in stone replicas and cemented into the preparations using 4 luting agents (n = 18 + 2 controls for each cement group): a resin composite used with a bonding agent (Variolink II/Excite), a resin composite used with a self-etching primer, but without bonding agent (Panavia F/ED Primer), a modified resin composite used with a bonding agent (Resinomer/One Step), and a resin-modified glass-ionomer cement (Fuji Plus). Thirty-six inlays (n = 9 + 1 control) were subjected to thermal cycling (2000 cycles, 5 degrees C/55 degrees C), whereas the other 36 were not. All the teeth were then immersed in 1% methylene blue dye solution for 48 hours. Microleakage score, margin location (enamel/cementum), thermal cycling history, and preparation location (buccal/lingual) were analyzed using a multivariate model (alpha = .05). Multivariate analysis was performed using a polychotomous logistic regression. RESULTS: The preparation location had no significant effect on dye penetration. The margin location (enamel or cementum) and the thermal cycling had a significant effect on microleakage (odds ratios [ORs] = 17.6 and 8.04, respectively). In comparing the 3 resin-based luting agents (Variolink II, Panavia F, and Resinomer) to Fuji Plus, Panavia F exhibited the lowest significant overall microleakage (OR = 0.09), followed by Variolink II (significant OR equal to 0.43), whereas Resinomer demonstrated the greatest significant overall microleakage (OR = 1.35). CONCLUSION: Within the experimental conditions of this in vitro study, thermal cycling significantly increased microleakage (OR = 8.04). The overall microleakage at the enamel margins was significantly lower than the overall microleakage at the cementum margins for the 4 luting agents tested (OR = 17.6).

Penetration and microleakage of dental sealants in artificial fissures.

This study investigated sealant penetration and dye microleakage of a resin composite system, a compomer system, and a resin-modified glass-ionomer cement in artificially grooved fissures in human molars. Ionosit Seal penetrated 99% of the artificial crevices, whereas Dyract Seal penetrated 97%. The penetration of Helioseal F at 90% was statistically different (P<.0001) from the other 2 materials. Microleakage dye penetration occurred in 22% of the Dyract Seal samples, while it occurred in 5% of Healioseal F and 7% of Ionosit Seal samples. The viscosity and flow properties of the 3 sealants allowed the materials to penetrate the artificial grooves, but they did not seem to affect their sealing capacity.

Importance of water sorption and solubility studies for couple bonding agent--resin-based filling material.

This study investigated the water sorption and solubility of two light-cured resin composites (Filtek P60 and Solitaire 2), one compomer (Compoglass F), one ormocer (Admira) and the associated bonding agents (Scotchbond 1 [Scotchbond 1 = Scotchbond Single Bond in USA], Gluma One Bond, Excite and Admira Bond, respectively) and of a RMGIC (Fuji II LC). Five disks of each product type were subjected to water sorption and solubility tests based on ISO 4049 requirements. The data were subjected to Kruskal-Wallis and non-parametric multiple-comparison tests using ranked sums at 95% confidence interval. Fuji II LC showed the highest water sorption (167.5 microg/mm(-3)). Fuji II LC and Compoglass F had higher solubility values (8.3 and 10.0 microg/mm(-3), respectively) than the other materials. Bonding agents have very high water sorption and solubility values (between 77.4 and 355.4 microg/mm(-3) and between 75.9 and 144.9 microg/mm(-3), respectively) compared to the restorative materials. Gluma One Bond and Admira Bond showed lower sorption and solubility than Excite and Scotchbond 1.