Surface roughness evaluation of polished composite using three- dimension profilometry

Amal Abd El-Samad Sakrana, DDS, PhD,(a) Ossama Badie Abouelatta, BSc, MSc, PhD,(b) Hideo Matsumura, DDS, PhD,(c) Hiroyasu Koizumi, DDS, PhD,(c) and Naomi Tanoue, DDS, PhD(d)

(a)Mansoura University Faculty of Dentistry, (b)Mansoura University Faculty of Engineering, Mansoura, Egypt, (c)Nihon University School of Dentistry, Tokyo, Japan, and (d)Nagasaki University Hospital of Medicine and Dentistry, Nagasaki, Japan

Purpose: This study evaluated the surface roughness of two composite materials using a three-dimension (3D) profilometer following four clinically-acceptable finishing techniques.
Materials and Methods: Disk specimens (9×3 mm) made of two composite materials, Filtek Z250 and Pertac II Aplitip, (n=30) were prepared. Each material group was further subdivided into five additional groups (n=6). This provided a control group (unpolished) and four polishing technique groups described as follows: Arkansas stone, aluminum oxide disks (Sof-Lex), diamond point, or silicone points. A 3D profilometer was employed to measure the surface roughness parameters Sa, Ssk, Sku, Sz, Sdc, Spk, Sk, and Svk for each specimen. A diamond stylus tip with a 5μm radius was used at a tracing speed of 0.3 mm/s. The measured area was 0.948mm2. The results were expressed in μm and analyzed by analysis of variance (ANOVA).
Results: Scratches and striations were microscopically observed in polished specimens and the filler resin was clearly evident in the control. The results of ANOVA revealed that the polishing techniques had a statistically significant effect on Sa, Ssk, Sdc, Sk, and Svk, but not on Sku and Spk. The type of composite had a significant effect on Ssk, Sku, Sz and Spk, but not on Sa, Sdc, Sk, and Svk (P<0.01). Considering only the specimens grouped according to the polishing techniques, optimum smoothness was realized with diamond points and aluminum oxide disks, and the most surface irregularities were measured with for control and specimens polished with the silicone point. The mean value of roughness parameters of Pertac was lower than those recorded for Z250.
Conclusion: The diamond point provided the lowest roughness parameters whereas the silicone points and control recorded the highest roughness parameters. (Int Chin J Dent 2004; 4: 85-91.)
Clinical Significance: Fine diamond point and aluminum oxide were shown most suitable for polishing disc-shaped specimens of Z250 and Pertac composite because lower 3D roughness parameters were recorded. The Arkansas stone and silicone points appear less suitable for polishing of the composite materials tested.

Key Words: composite, polish, roughness, surface.