Factors affecting polymer network organization were studied in highly crosslinked acrylics of the type used in dental adhesive resins. The variables tested were comonomer content and processing conditions. BisEMA (2,2,-bis[4-(2-methacryloyloxyethoxy)-phenyl]propane) and BisEMA + TEGDMA (triethyleneglycol dimethacrylate) were cured with and without 25% comonomer. Comonomers had characteristics that are expected to influence intrachain organization in amorphous phases: TEGDMA, crosslinking; methyl methacrylate (MMA), monomer conversion; isobornyl methacrylate (IBM), low cure shrinkage; tetrahydrofurfuryl methacrylate (THFM), antiplasticization. Dynamic mechanical analysis temperature scans were run at 0.1 Hz 2h or 24h after ambient cure, or 24h postcure after heating at 75 degrees or 125 degrees C. After 24h, tan delta maxima occurred in ranges centering on approximately - 30 degrees, 75 degrees and 150 degrees C (T-g). Heating at 125 degrees C nearly eliminated all peaks except T-g, reduced tan delta peaks and increased T-g by 0-14 degrees. T-g increased in the order: TEGDMA>125 degrees C>IBM>MMA>75 degrees C>2h>24h>THFM. The ability to crosslink, and postcure heating at 125 degrees C, were the more important factors found to increase intrachain organization in amine-promoted, unfilled BisEMA resins of the type used in dental sealants, luting cements and bulk-filling resin composite materials.