Dental Wings CAD/CAM system precision: an internal and marginal fit sperimental analisys

Abstract

STATEMENT OF PROBLEM.: The CAD-CAM technology has been developed to design and manufacture prosthetic structures with constant quality characteristics; in fact procedures are codified, manageable and repeatable. PURPOSE.: The purpose of this in vitro study is to evaluate the internal and marginal gap of zirconia casts made with a new CAD-CAM systematic that use Dental Wings laser scanner and Yenamak milling machine. MATERIAL AND METHODS.: 6 analogs of solid abutments of Straumann implants were used, fixed in plexiglass bases. The samples were scanned by Dental Wings laser; the file obtained by scanning of each probe was sent to the Yenamak D40 milling machine, then the casts were sintered in Protherm furnace. Then 6 samples were cemented with resin luting agent capsules (Relyx Unicem, 3M ESPE). The samples were incorporated in transparent epoxy resin. After resin hardening, the cylinders obtained were cut with a microtomes. These slices thus obtained were then polished with a Polisher sander with alumina dust decreasing grain. Each section was observed and photographed in reflected light with the aid of an optic microscope type, first at low magnification and then at higher magnification. RESULTS.: The overall average fitting of copings on the abutments was 32,87 μ. No differences were found in marginal fit on buccal and lingual sides, it was easily predictable because of the standard form of the used stumps. The recorded values for the marginal fit were lower than those of axial walls. The accuracy of adaptation was always achieved within the limits of clinical acceptability. CONCLUSIONS.: Within the limitations of this study, the system evaluated represents a valuable alternative to conventional prosthetic rehabilitation techniques.

Keywords: CAD-CAM; marginal fit; zirconia.

Figure 1

Analog fixed in plexiglass bases.

Figure 2

Scanner DW – 5 – 140 Dental Wings (Dental –Wings Inc., Montreal QC, Canada).

Figure 3

Scanning plate.

Figure 4

3D scanning and finish line detection.

Figure 5

Milling machine.

Figure 6 a, b

Sintered coping accuracy examination.

Figure 7

Resin cuting acent capsules.

Figure 8 a, b, c

Sample placed on cementation devices (a); costant load (b); cemented coping (c).

Figure 9 a, b

Transparent epoxy resin (a) incorporated samples (b).

Figure 10 a, b

Buehler Isomet Plus Microtomes (a) e selectioned model (b).

Figure 11

Beuhler Metaserv Grinder Polisher sander.

Figure 12

Axiophot Zeiss microscope.

Figure 13

Coping n° 3: lingual marginal gap at 50x magnification.

Figure 14

Coping n°4: vestibolar marginal gap at 100x magnification.

Figure 15

Coping n° 2: lingual marginal gap at 200x magnification.

Figure 16

Coping n° 1: oclusal gap at 100x magnification.

Figure 17

Coping n° 5: lingual marginal gap at 500x magnification.