US EPA

3070910 

Journal Article 

A study to investigate and compare the physicomechanical properties of experimental and commercial temporary crown and bridge materials 

Abdulmohsen, B; Parker, S; Braden, M; Patel, MP 

2015 

Yes 

Dental Materials
ISSN: 0109-5641
EISSN: 1879-0097 

32 

2 

200-210 

English 

26748979 

10.1016/j.dental.2015.11.025 

OBJECTIVES: To develop two experimental temporary crown and bridge materials with improved physicomechanical properties.

METHODS: Commercial materials: Trim (TR, monomethacrylate, Bosworth) and Quicktemp2 (QT, dimethacrylate, Schottlander).

EXPERIMENTAL MATERIALS: isobutyl methacrylate/poly(ethyl methacrylate) (IBMA/PEM) and n-butyl methacrylate/PEM (nBMA/PEM), both monomethacrylates. For water absorption/desorption studies rectangular samples (40mm×10mm×1mm) of each material were prepared, immersed in deionized water (DW, control) and artificial saliva (AS), and weighed at regular time intervals. %solubility and diffusion coefficients (D) for uptake/loss processes were calculated and compared with theoretical predictions. Polymerization exotherm (cylindrical samples 10mm×18mm) and flexural moduli were measured (three point bending; rectangular samples 80mm×10mm×4mm, dry and after 9 days storage in DW). The data were compared statistically.

RESULTS: QT and nBMA/PEM had lower %equilibrium uptakes/loss in DW (0.68%/0.884% and 0.64%/0.895% respectively). QT had the lowest water absorption/desorption D (P<0.05) compared to the three monomethacrylates, in DW and AS. %solubility for all systems showed no differences in DW (P>0.05), but a difference for QT in AS (P<0.05). QT reached its maximum temperature rapidly (∼2min; 3 monomethacrylates ∼7-13min). The commercial materials exhibited high peak temperatures (∼51°C, P<0.05; experimental materials ∼43°C). QT had a higher flexural modulus (∼4GPa; 3 monomethacrylates ∼0.7-1GPa) for dry and wet samples. The moduli for commercial materials reduced significantly after immersion in DW; there was no difference between the dry and wet experimental materials samples (P>0.05).

SIGNIFICANCE: The experimental materials merit further studies since they presented with lower setting exotherms, and contained no phthalate plasticizer, thus being less of a risk to patients.