Changes of cement properties caused by mixing errors: the therapeutic range of different cement types.

Objective: The hypothesis was that low grade variations of mixing ratios of luting agents have negligible influence, while high grade variations cause severe property changes independent from the cement type used.

Material And Methods: A zinc oxide phosphate, carboxylate, glass ionomer, resin-modified glass ionomer, dual-curing composite and self-adhesive composite cement were mixed using various mixing ratios. Beside the recommended ratio, samples were mixed with ratios between 10 and 25% (low grade) up to 60% (high grade) variation of powder/liquid, respectively base/catalyst pastes.

Effect of variations from the recommended powder/liquid ratio on some properties of resin-modified cements.

Objectives: The powder and liquid contents of cements are mixed in accordance with the recommended mixing ratio, but discrepancies occur despite the use of proportioning scoops. Little is known about powder/liquid ratio variations on certain properties of resin-modified cements.

Methods: Two resin-modified glass ionomer cements (RMGIC) were mixed using various powder/liquid ratios: (a) Recommended ratio: Fuji Plus: powder/liquid 2:1; ProTecCEM p/l 2.