Influence of the finishing technique on surface roughness of dental porcelains with different microstructures.

UNLABELLED This study compared the surface roughness of 4 dental porcelains with different microstructures (d.Sign-D, Finesse-F, Noritake-N and Symbio-S) using varied surface treatments. The porcelain surfaces were submitted to the following surface treatments: 1) g (glazing only); 2) rg (polishing with a rubber wheel before glazing); 3) 2g (reglazing); 4) r (rubber wheels); 5) rp (rubber wheels + diamond paste); 6) d (sandpaper discs) and 7) dp (sandpaper discs + diamond paste). Treatments 3 through 7 were performed after breaking the glaze layer with a diamond bur. Surface roughness (Ra, in m) was determined using a profilometer (n=10). Visual inspection was made using the scanning electron microscope. Microstructural characterization was also performed (hardness, leucite content and particle size). Reglazed specimens presented significantly rougher surfaces compared to glazed specimens. The use of a polishing paste after the sandpaper discs or after the rubber wheel resulted in a reduction of the Ra value for all materials (except for the dp group of porcelain S). Rubber or discs followed by diamond paste were the best surface treatments for porcelains D (D-rp: 0.21 +/- 0.06 microm and D-dp: 0.22 +/- 0.05 microm) and F (F-rp and F-dp: 0.17 +/- 0.03 microm). For porcelains N and S, both reglazing (2g) and the use of rubber or sandpa- per discs followed by diamond paste (groups rp and dp) resulted in similar roughness (N-2g: 0.22 +/- 0.03 microm; N-rp: 0.22 +/- 0.04 microm; N-dp: 0.20 +/- 0.04 microm, S-2g: 0.22 +/- 0.04 microm; S-rp: 0.19 +/- 0.04 microm; S-dp: 0.23 +/- 0.04 microm). CONCLUSION The best choice of surface treatment for leucite-based porcelains depended on the material considered. Porcelains with lower leucite content (F and S) tended to present lower roughness compared to those with higher leucite content after being polished with rubbers or discs followed by diamond pastes.

[1]  M S Scurria,et al.  Surface roughness of two polished ceramic materials. , 1994, The Journal of prosthetic dentistry.

[2]  M Quirynen,et al.  The influence of surface roughness and surface-free energy on supra- and subgingival plaque formation in man. A review of the literature. , 2005 .

[3]  W. G. Taylor,et al.  Refinishing of porcelain by using a refinishing kit. , 1991, The Journal of prosthetic dentistry.

[4]  Gudbrand Osilo.  Flexural strength and internal defects of some dental porcelains. , 1988 .

[5]  K. Anusavice,et al.  Effect of Firing Temperature and Water Exposure on Crack Propagation in Unglazed Porcelain , 1989, Journal of dental research.

[6]  H. O. Heymann,et al.  Effects of water, speed, and experimental instrumentation on finishing and polishing porcelain intra-orally. , 1989, Dental materials : official publication of the Academy of Dental Materials.

[7]  S. Ebisu,et al.  Effect of surface roughness of porcelain on adhesion of bacteria and their synthesizing glucans. , 2000, The Journal of prosthetic dentistry.

[8]  S. Rosenstiel,et al.  Comparison of glazed and polished dental porcelain. , 1989, The International journal of prosthodontics.

[9]  M. Bergman,et al.  Polishing systems for dental ceramics. , 1993, Acta odontologica Scandinavica.

[10]  R. Kusy,et al.  Polishing porcelain veneers: an SEM and specular reflectance analysis. , 1988, Dental materials : official publication of the Academy of Dental Materials.

[11]  G. T. Charbeneau,et al.  Polished versus autoglazed porcelain surfaces. , 1982, The Journal of prosthetic dentistry.

[12]  D F Taylor,et al.  Studies on the wear of porcelain, enamel, and gold. , 1971, The Journal of prosthetic dentistry.

[13]  T. Hegdahl,et al.  On the measuring of roughness , 1981 .

[14]  W. H. Tate,et al.  Surface roughness of opalescent porcelains after polishing. , 1995, Operative dentistry.

[15]  N. Barghi,et al.  When to glaze--an electron microscope study. , 1976, The Journal of prosthetic dentistry.

[16]  M. Wolff,et al.  An evaluation of adjustment and postadjustment finishing techniques on the surface of porcelain-bonded-to-metal crowns. , 1982, The Journal of prosthetic dentistry.

[17]  M. Fuzzi,et al.  Scanning electron microscopy and profilometer evaluation of glazed and polished dental porcelain. , 1996, The International journal of prosthodontics.

[18]  W. Sulik,et al.  Surface finishing of dental porcelain. , 1981, The Journal of prosthetic dentistry.

[19]  L. Tedesco,et al.  Clinical discrimination between autoglazed and polished porcelain surfaces. , 1990, The Journal of prosthetic dentistry.

[20]  R. Draughn,et al.  A study of porcelain surfaces as utilized in fixed prosthodontics. , 1975, The Journal of prosthetic dentistry.