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Purpose: To analyze in vitro artificial secondary caries inhibition around conventional luting cements and resin cements using a confocal laser-scanning microscope (CLSM)., Methods: Box shape cavities (approximately 3 mm long, 4 mm wide, and 1.5 mm deep) were prepared in bovine root dentin. One of five cements: Elite Cement 100 (EL) zinc phosphate cement, HY-Bond Carbo Cement (CA) polycarboxylate cement, Fuji I (FI) glass-ionomer cement, Fuji Luting (FL) GIC-based resin cement and Panavia F (PA) fluoride-releasing resin cement, was placed in the cavity. After polishing, the center of the cement surface was covered with an adhesive to preserve the original cement solubility. The specimens were stored in distilled water at 37 degrees C for 1 week, and stored in an artificial demineralizing solution for 3.5 days. Following this, each specimen was sectioned into two halves, trimmed, and polished. Thickness of inhibition zone, depth of outer lesion and cement solubility around each cement were determined by a CLSM., Results: Inhibition zones were not seen in EL and CA, while they were found in FI, FL and PA. The depths of the outer lesions of CA and FI were significantly lower than those of EL, FL and PA (P< 0.05). The highest and the second-highest cement solubility were obtained in EL and CA, respectively. FI and FL indicated significantly lower cement solubility than EL and CA. PA tended to show the lowest cement solubility.

This paper reviews the causes of barodontalgia and reports on a study that indicates a possible cause of barodontalgia in the diver. In the study, extracted teeth had full cast crowns cemented with either a zinc phosphate, a glass ionomer, or a resin cement, and simulated diving to 30 m (3.0 atmospheres) was performed. During simulated diving, the teeth were pressure cycled 15 times to 3 atmospheres and microleakage was monitored. The force required to dislodge the crown was then tested; a significant difference was found between the zinc phosphate and the glass ionomer cement groups (p < 0.01). No difference was found between the resin cement groups. Microleakage was also detected in the zinc phosphate and glass ionomer cement groups and was found to occur sooner, and to a greater extent with zinc phosphate. No microleakage was detected in the resin cement experimental group. This study showed that the retention of full cast crowns to extracted teeth is reduced after pressure cycling and that microleakage does occur if the crowns are cemented with either zinc phosphate cement or glass ionomer cement.

Unifas cement was used for fixation of cermet dentures in 104 patients. Clinical follow-up of 3 months to 3 years duration demonstrated sufficiently high adhesive characteristics, resistance to oral fluid and mechanic loading effects of this cement, which is recommended for wide clinical practice.