Surface Roughness of Milled Lithium Disilicate With and Without Reinforcement After Finishing and Polishing: An In Vitro Study

Abstract

Purpose To determine the efficacy of various finishing and polishing techniques on the surface roughness of two computer‐aided design/computer‐aided manufacturing (CAD/CAM) materials, lithium disilicate (IPS e.max), lithium disilicate reinforced with lithium aluminosilicate (Straumann® n!ce™), and a stackable low‐fusing nanofluorapatite glass ceramic (Ceram). Materials and Methods Flat specimens (n = 12) per treatment group were fabricated 2 mm thick, 15 mm in length, and 12mm in width. Samples were either glazed or polished. Glazing was accomplished with either Ivoclar IPS e.max CAD crystall glaze spray or IPS e.max Ceram glaze paste, according to manufacturer instructions. Three different polishing systems were tested: Brasseler Dialite HP, Ivoclar OptraFine, and Komet LD/ZR. Polishing was performed using a Kavo adjustable slow speed electric contra‐angle handpiece mounted to an oscillating Toothbrush Dentifrice Assessment Instrument. Surface roughness data was collected using a benchtop stylus profilometer and analyzed for statistical significance using two‐way ANOVA (α = 0.05). Representative scanning electron micrograph images were generated for all samples. Results Overall there was no significant difference in Ra when comparing types of ceramic (p = 0.9315, F = 0.071). However, there was a statistically significant difference when comparing groups of finishing treatments (p < 0.001, F = 113.5) and also when comparing finishing treatment with ceramic type (p < 0.001, F = 11.13). No significant difference was found with IPS e.max CAD crystall glaze spray on Straumann® n!ce™ versus IPS e.max Ceram glaze paste on IPS e.max Ceram (p = 0.8745) or IPS e.max CAD crystall glaze spray on IPS e.max versus IPS e.max Ceram glaze paste on IPS e.max Ceram (p = 0.3373). Significant differences in Ra of Straumann® n!ce™ were found when comparing Brasseler with Ivoclar (p = 0.0014) and Ivoclar with Komet (p = 0.047). No significant difference was observed between Brasseler and Komet (p = 0.8099). Conclusions It appears that the degree of surface roughness depends upon the specific finishing system and ceramic combination used. Straumann® n!ce™ is more efficiently polished using Brasseler Dialite HP or Komet LD/ZR polishing systems. Ivoclar crystal glaze spray was found to be equally as effective on Straumann® n!ce™ and IPS e.max as IPS e.max Ceram glaze paste on IPS e.max Ceram.

Experimental Study of Surface Roughness of Dental Ceramics After Polishing with Three Types of Polishing Systems

“…They also found that polishing could create residual compressive strength that would further harden the surface of the ceramic restoration. Although various polishing systems for ceramic restoration have been widely studied,[ 2 3 4 5 6 7 8 9 10 11 12 ] most studies focused on the roughness of ceramics polished by their specific ceramic polishing systems compared with other methods such as Sof-Lex,[ 2 ] Identoflex[ 3 4 ] or diamond polishing paste. [ 3 4 5 6 ] Some studies compared the roughness of ceramics between feldspathic and zirconia polishing sets[ 7 8 9 ] or the effectiveness of universal ceramic polishing sets.…”

“…[ 3 4 5 6 ] Some studies compared the roughness of ceramics between feldspathic and zirconia polishing sets[ 7 8 9 ] or the effectiveness of universal ceramic polishing sets. [ 10 11 12 ] There has been limited data regarding the effectiveness of the lithium disilicate polishing set. Therefore, this study aimed to examine the surface roughness of three types of dental ceramics after polishing with three extraoral ceramic polishing systems: feldspathic porcelain, lithium disilicate, and zirconia polishing systems.…”

Effect of sintering on the translucency of CAD–CAM lithium disilicate restorations: A comparative in vitro study

“…Translucency is an important optical property for dental ceramics needed to mimic natural dentition. Translucency has been described as the amount of light transmitted or diffused from the substrate 11,12 . Even though pigments can be applied to dental ceramics to obtain a high translucency look, this stain can be lost within a few months after exposure to everyday products such as toothpaste and beverages such as tea and coffee 13,14 .…”

Comparative Study of the Effectiveness of Laboratory‐Formulated Polishing Pastes for Two CAD/CAM Ceramic Restorative Materials

“…However, precautions should be considered during polishing as thinning of ceramic restorations might occur which increases the risk of ceramic fracture 12 . However, other studies have found no difference in surface roughness of dental ceramics after using either polishing pastes/kits or glazing techniques 17,18 . This might be due to the difference in composition of dental ceramics and particle size studied.…”

“…12 However, other studies have found no difference in surface roughness of dental ceramics after using either polishing pastes/kits or glazing techniques. 17,18 This might be due to the difference in composition of dental ceramics and particle size studied.…”