Author(s)

Shivaughn M. Marchan^1*, Anna Kay Bishop¹, William A. J. Smith¹, Paul Seerattan², David Hinds³

¹Unit of Restorative Dentistry, School of Dentistry, Faculty of Medical Sciences, The University of the West Indies, St Augus-tine, Trinidad and Tobago.
²School of Dentistry, Faculty of Medical Sciences, the University of the West Indies, St Augustine, Trinidad and Tobago.
³Department of Physics, Faculty of Science and Technology, the University of the West Indies, St Augustine, Trinidad and Tobago.

Purpose: This study assessed the roughness of two injection-molded, thermoplastic materials used for denture bases compared with a polyamide material and compression molded Polymethylmethacrylate (PMMA) after the adjustment and re-polishing with either a laboratory protocol or a chair side protocol. Methods: Forty specimens, each of PMMA, Valplast, DuraFlex, Dura Cetal were fabricated and finished according to individual manufactures’ instructions. These materials were adjusted with tungsten carbide (TC) burs to mimic gross adjustments, and then re-polished either on a lathe or bonded silicon carbide (B-SC). Following instrumentation, the specimens were assessed using contact profilometry and scanning electron microscopy. Two-factor ANOVA was used to determine significant differences in mean surface roughness (R_a and R_max), with included factors being material type and re-polishing regimen. Results: Mean R_a values ranged from 0.26 (DuraFlex control) to 1.82 (Valplast adjusted with TC burs). Mean R_max values ranged from 1.88 (Dura Flex control) to 13.76 (Valplast adjusted with TC burs). Two-factor ANOVA revealed that interaction of both factors was significant (p < 0.05) for R_a and R_max. There was a statistically significant increase in both R_a (p < 0.05) and R_max (p < 0.05) for all material types following the gross adjustment. With the exception of DuraFlex, re-polishing of samples that were previously adjusted with TC burs, on the dental lathe produced surfaces that were comparable to control samples. Conclusion: Adjustment of DuraFlex should be kept to a minimum since the adjustment produced the significant surface detriment that could not be corrected with either of the polishing regimens.

DuraFlex, DuraCetal, Valplast, Poly Methylmethacrylate, Surface Roughness

Marchan, S. , Bishop, A. , Smith, W. , Seerattan, P. and Hinds, D. (2017) A Comparative Assessment of the Surface Roughness of Thermoplastic Denture Base Resins Following Adjustment and Re-Polishing. Open Journal of Stomatology, 7, 250-263. doi: 10.4236/ojst.2017.74019.