The effect of time of trimming on the surface finish of anterior composite resins

Abstract

This in vitro study investigates whether the surface smoothness of a finished composite resin is a function of the time at which it is trimmed. Five materials were studied. Visiodispers (VIS) is a sintered microfine, the remainder were hybrid formulations: Miradapt (MIR), Command Ultrafine (COM) and two experimental formulations-'EXP (2)' and 'EXP (15)'-with larger filler particles. All except MIR were photo-activated. Samples were placed and cured in holes machined in Perspex rods, ensuring excess of material and moulded to shape with cellulose acetate matrix strip. The strips were removed immediately after light curing and after 5 min in the case of MIR. Sample groups were finished after the following intervals: 10, 15, 30, 45s, 1, 2, 3, 4, 5 min, dry, and after 1 and 7 days in 37 degrees C water. The finishing procedure used plain-cut tungsten-carbide burs and coarse, medium and fine finishing discs, which were applied for standardized times, directions and pressures. Surface roughness was assessed visually and with a surface profilling instrument. COM and VIS materials significantly improved in surface finish when the procedure was delayed for 7 days. However, EXP (2), EXP (15) and MIR surface finishes were independent of finishing time. This may result from a rapid attainment of optimum surface hardness, whereas with COM and VIS incomplete curing leads to smearing of resins and filler across the surface.

Impact of Polishing Systems on the Surface Roughness and Microhardness of Nanocomposites

“…33 Although the surface obtained with Mylar strip is perfectly smooth, studies have shown that the outermost layer, which is rich with resin organic binder, has to be removed to produce a harder, wear resistant and esthetically stable surface. 11,16,20,31,34 Though both polishing systems tested in this study showed similar results in two composite systems, Ceram-X showed relatively lower values. The flexibility, hardness, and the granulations of the polishing system can influence the surface roughness of restorative materials.…”

“…29,30 However, leaving resin surfaces as such is unacceptable due to the presence of the oxygen-inhibited layer, which will result in high water absorption and discoloration. 11,16,20,31 The surface roughness of composite resins is influenced by the size, hardness, and amount of filler material. 32 The surface roughness varied with the polishing systems and the type of composite used.…”

Effect of Dental Finishing Instruments on the Surface Roughness of Composite Resins as Elucidated by Atomic Force Microscopy

“…Therefore, superficial smoothness is one of the most important properties of a successful restoration~Joniot et al, Nagem Filho et al, 2003, Yazici et al, 2007!. Many studies~Lutz et al, 1983Heath et al, 1993;Nagem Filho et al, 2003;Roeder & Powers, 2004! have shown that polyester matrices provide smooth surfaces.…”

“…Thus, finishing dental instruments become indispensable to improving restoration margins, removing overhangs, and producing appropriate contours~Lutz et al, 1983;Jung et al, 1997;Yap et al, 1998;Turssi et al, 2000;Ozgunaltay et al, 2003;Turkun & Turkun, 2004!. Carbide burs~Lutz et al, 1983Boghosian et al, 1987;Berastegui et al, 1992;Ferracane et al, 1992;Heath et al, 1993;Jung et al, 1997;Joniot et al, 2000;Reis et al, 2002!, diamond burs~Lutz et al, 1983Boghosian et al, 1987;Berastegui et al, 1992;Ferracane et al, 1992;Joniot et al, 2000;Lopes et al, 2002;Reis et al, 2002;Nagem Filho et al, 2003!, abrasive impregnated rubber cups and points ~Yap et al, 1998;Joniot et al, 2000;Turssi et al, 2000!, abrasive strips, stones~Lutz et al, 1983Bagheri et al, 2005!, polishing pastes~Yannikakis et al, 1998Turssi et al, 2000!, andabrasive discs~Lutz et al, 1983;Berastegui et al, 1992;Heath et al, 1993;Yannikakis et al, 1998;Joniot et al, 2000;Turssi et al, 2000;Lopes et al, 2002;Reis et al, 2002;Nagem Filho et al, 2003;Roeder & Powers, 2004! have been used for finishing and polishing...…”

“…Rough surfaces of composite resins contribute to bacterial plaque, debris, and staining accumulation~Heath et al., 1993;Yap et al, 1998Yap et al, , 2000Wilder et al, 2000;Lopes et al, 2002;Reis et al, 2002Reis et al, , 2003Nagem Filho et al, 2003!. These factors may cause gingival inflammation~Yap et al, 1998inflammation~Yap et al, , 2000Wilder et al, 2000;Lopes et al, 2002;Reis et al, 2003;Nagem Filho et al, 2003!, secondary caries~Yap et al, 1998Lopes et al, 2002;Reis et al, 2003!, superficial staining~Heath et al, 1993Yap et al, 1998Yap et al, , 2000Wilder et al, 2000;Lopes et al, 2002;Reis et al, 2002Reis et al, , 2003Nagem Filho et al, 2003; 2005!, and reduction of the restoration gloss~Paravina et al, 2004!.…”