Marginal and Internal Discrepancies Related to Margin Design of Ceramic Crowns Fabricated by a CAD/CAM System

Abstract

The RS finish line produced MD values significantly lower than tilted and large chamfer, but large chamfer presented the lowest internal discrepancy values. Independent of the finish line type, internal discrepancy was the lowest in the axial region followed by radius and occlusal regions.

Clinical evaluation comparing the fit of all-ceramic crowns obtained from silicone and digital intraoral impressions based on wavefront sampling technology

“…The replica technique is accepted as a reliable and non-invasive means to determine the in vivo adaptation of crown-to-tooth surfaces. 20,[23][24][25][26] A modification of the previously described technique in the handling and stabilisation of the replicated silicone layer was used. The misfit replicated space is thin and fragile, with a thickness ranging from 20to 150 mm.…”

“…To register the space between the inner surface of the copings and the abutment, a modified replica technique was applied 11,12,[22][23][24][25][26] : 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 Fig. 1 -Stereolithographic cast produced by rapid prototyping.…”

Microleakage of Glass Ionomer-based Provisional Cement in CAD/CAM-Fabricated Interim Crowns: An in vitro Study

“…In addition, the margin configuration was a radial shoulder instead of a deep chamfer because a shoulder exhibited smaller marginal gap in previous reports. 16,17 For the thermocycling process, the small number of thermocycles which was performed corresponded to the short period of service of provisional restoration in the oral cavity. Moreover, the temperature range of the cycles is more important than the number of cycles.…”

Ajuste marginal e interno de restaurações de cerâmica pura fabricadas em CAD / CAM: uma revisão da literatura

“…According to the research by Souza et al, 9 the beveled shoulder finishing produces a smaller marginal maladjustment, while deep chamfer is associated with a better internal adaptation. On the other hand, Jalali et al, 32 did not observe any difference among the group of teeth that received a shoulder finishing and the other group, in which a shoulder finishing was made in the vestibular wall associated with chamfer in the proximal and lingual walls.…”

“…Thus, an overdone cement line creates a place of force concentration and it constitutes a local for the fracture initiation. 9,10 Many factors reported in literature affect the restoration adaptation, as design preparation, restoration material, end localization, mold technique and material, fabrication method, among others. 11 Regarding the all-ceramic fabrication method, it is highlighted the techniques using lost wax, ceramic injection, and the systems of computer-aided design and computer-aided manufacturing (CAD/CAM).…”