Evaluation of Surface Roughness of Ceramic and Resin Composite Material Used for Conservative Indirect Restorations, after Repolishing by Intraoral Means.
OBJECTIVE
To evaluate and compare the mean surface roughness (Ra) of one ceramic and one resin composite material used for indirect restorations, after grinding and repolishing by intraoral means.


METHODS
The materials used were the lithium disilicate glass ceramic IPS e.max Press (EMP) and the indirect resin composite restoration system Gradia (GR). Twelve specimen disks were prepared from each material according to the manufacturer of each material. Five initial measurements of the Ra (Ra1) were made on each specimen as a referral basis, and the specimens were ground with a fine (red) diamond bur. The specimens were repolished using (a) Komet Dialite Polishing Kit for EMP and (b) Enhance Finishing and Polishing System and Prisma Gloss Polishing Paste for GR. Five final Ra (Ra2) measurements were performed on each specimen. All measurements were made using a laser profilometer. Scanning electron microscopy (SEM) was also used to visualize the initial surface morphology and the morphological changes on the specimens' surface after repolishing.


RESULTS
A highly significant difference was found between Ra1EMPand Ra2EMP(p < 0.001), between Ra1GRand Ra2GR(p < 0.001), as well as between Ra2EMPand Ra2GR(p < 0.001), when compared in pairs. A highly significant difference (p < 0.001) was also found between ΔRaEMPand ΔRaGR, with ΔRaGRbeing higher than ΔRaEMP. The RaGRvalues were higher than the RaEMPvalues at all times. SEM revealed that both EMP and GR repolished surfaces presented with irregularities; however, in GR specimens major voids and craters were present.


CONCLUSIONS
EMP was found to perform better when polished by intraoral means compared with GR. Both materials exhibited Ra2above the critical threshold for increased plaque accumulation and periodontal inflammation. If enamel-to-enamel roughness found in occlusal contact areas is considered as baseline, both materials were clinically acceptable after repolishing.
School of Dentistry and Oral Health, Centre for Medicine and Oral Health, Griffith University, Gold Coast Campus, Gold Coast, QLD, Australia.
Areti D
AD
Vrochari
Department of Prosthodontics, School of Dentistry, National and Kapodistrian University of Athens, Greece.
Aikaterini
A
Petropoulou
School of Dentistry and Oral Health, Centre for Medicine and Oral Health, Griffith University, Gold Coast Campus, Gold Coast, QLD, Australia.
Vasilios
V
Chronopoulos
Department of Operative Dentistry and Periodontology, University School and Hospital, Albert Ludwigs University Freiburg, Freiburg i. Br., Germany.
Olga
O
Polydorou
School of Dentistry and Oral Health, Centre for Medicine and Oral Health, Griffith University, Gold Coast Campus, Gold Coast, QLD, Australia.
Ward
W
Massey
Department of Operative Dentistry and Periodontology, University School and Hospital, Albert Ludwigs University Freiburg, Freiburg i. Br., Germany.
Elmar
E
Hellwig
D003188:Composite Resins; D003775:Dental Polishing; D003776:Dental Porcelain; D003793:Dental Restoration, Permanent; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties
D003188:Composite Resins; C470230:Gradia; C508050:IPS e.max Press; D003776:Dental Porcelain
Intraoral polishing; SEM; composite resin; laser profilometer; lithium disilicate glass ceramic; repolishing; surface roughness