Effect of amine activators on the properties of chemical cured dental composites

In-depth polymerization of dual-cured resin cement assessed by hardness

This study investigates the in-depth polymerization of dual-cured resin cement (Enforce; Dentsply, shades A2, B1, and opaque). Cylindrical specimens are obtained by photo-activation through ceramic. Control samples are light-cured without using ceramic. Samples are tested after 15 min or 24 h. Knoop hardness readings are made at 100, 300, 500, and 700 microm depth. Hardness is generally dependent on the mode of activation and post-cure time. Shades A2 and B1 show higher hardness values than opaque resin. Hardness at 100 microm is higher than at 700 microm. A linear relationship between hardness and depth is observed.

Temporary restorative resins using non-phthalate ester plasticizers

OBJECTIVE

This study examined temporary restorative resins that use non-phthalate ester plasticizers.

METHODS

Three non-phthalate plasticizers were tested: tri-ethyl citrate (TEC), tri-butyl citrate (TBC), and di-butyl sebacate (DBS). The experimental resins were compared with resins that use a phthalate ester plasticizer (di-butyl phthalate, DBP) and commercial products (Dura Seal, Plast Seal, and Fit Seal). For the experimental resins, the ratio of plasticizer to PMMA/MMA resin was varied from 30 to 60% (wt). The mechanical properties of the experimental resins were evaluated using a modified diametral compressive strength and the resistance to explorer insertion.

RESULTS

The strengths of the experimental resins with plasticizer concentrations ranging from 40 to 50% (TEC, TBC, and DBP) or from 30 to 40% (DBS), by weight, were equivalent to the strengths of commercial temporary restorative resins. A similar tendency was seen for the resistance to explorer insertion.

CONCLUSIONS

The results suggest that new temporary restorative resins can be prepared by choosing the appropriate proportions of resin monomer and non-phthalate ester plasticizer.

Dental materials citations: Part A, January to June 1997

OBJECTIVE

A search was conducted in biomedical journals published from January 1997 to June 1997 to identify all dental materials publications and sort them into major categories.

METHODS

Tables of contents for 79 journals for the period of January to June, 1997 were inspected and divided into 17 categories. Citations were analyzed by both frequency in journals and in categories, as well as compared to frequencies for previous years.

RESULTS

A total of 445 citations were detected in 79 journals for the period January 1997 to June 1997. Certain journals (n = 19) demonstrated a higher citation frequency (> or = 10 citations for 6 months) and represented 77.8% of all citations. The greatest number of citations continued to involve bonding (n = 97), resin-based restorative materials (composites; glass ionomers) (n = 95), prosthodontic materials (n = 51), and pulp protection/luting materials (n = 48). Frequencies by category were very similar to those for the last four years.

SIGNIFICANCE

The compiled literature citations provide a supplement for researchers and academicians seeking information in existing electronic databases.