Abstract
Statement of problem
Selective laser melting (SLM) technology has been introduced for printing metal dental
restorations from Co-Cr base alloys or Au-Pt high noble alloys. However, information
regarding the fit of restorations fabricated by using this technique is limited.
Purpose
The purpose of this in vitro study was to determine the effect of 3 different finish
line designs on the marginal and internal gaps of metal copings made from a base (Co-Cr),
high noble (Au-Pd-Ag), and noble alloy (Co-Pd) by using the SLM technology.
Material and methods
Three Ivorine right maxillary central incisors were prepared with a chamfer, deep
chamfer, or shoulder finish line. The preparations were scanned by using a TRIOS scanner,
and a total of 90 dies were printed using DPR 10 Resin (30×3 finish line designs).
Ten SLM copings were fabricated for each margin design and metal alloy combination
for a total of 90 copings (10×3 finish line designs×3 alloys). Copings were cemented
onto dies using an autopolymerizing composite-resin luting material. All coping-die
assemblies were sectioned buccolingually by using a low-speed diamond saw, and images
were obtained by using an inverted bright field metallurgical microscope at ×100 magnification.
Marginal and internal gaps were measured at 5 locations: buccal margin, midfacial,
incisal, midlingual, and lingual margin. After gap measurements, representative specimens
were embedded in autopolymerizing resin and prepared for metallographic examination.
A 2-way multivariate analysis of variance (MANOVA) was conducted to determine the
overall significance, followed by ANOVA for each dependent variable (α=.05).
Results
The results indicated that alloy type and finish line had a significant influence
on marginal gap of copings (P<.001). Relative to the internal gap, alloy type had a significant effect (P<.001), but the type of finish line had no statistically significant influence (P=.337). No statistically significant interactions occurred. Base alloys were printed
with almost no observable porosity, whereas noble and high noble alloys exhibited
hot tears and porosity.
Conclusions
Thefinish line type did not influence the internal gap between copings and dies, whereas
the alloy type influenced the marginal gap between copings and dies. SLM-fabricated
Co-Cr copings on teeth prepared with a deep chamfer finish line demonstrated the lowest
marginal gap.
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References
- Marginal and internal fit of all-ceramic CAD/CAM crown-copings on chamfer preparations.J Oral Rehabil. 2005; 32: 441-447
- A review of dental CAD/CAM: Current status and future perspectives from 20 years of experience.Dent Mater J. 2009; 28: 44-56
- Clinical performance of chairside CAD/CAM restorations.J Am Dent Assoc. 2006; 137 Suppl: 22S-31S
- The future of dental devices is digital.Dent Mater. 2012; 28: 3-12
- Selective laser melting technique of Co-Cr dental alloys: A review of structure and properties and comparative analysis with other available techniques.J Prosthodont. 2015; 24: 303-312
- Bourell D. International solid freeform fabrication symposium: an additive manufacturing conference. University of Texas at Austin, Austin, TX2011: 227-238
- Internal fit evaluation of crowns prepared using a new dental crown fabrication technique: Laser-sintered Co-Cr crowns.J Prosthet Dent. 2009; 102: 253-259
- Binding mechanisms in selective laser sintering and selective laser melting.Rapid Prototyp J. 2005; 11: 26-36
- Microstructures and mechanical properties of Co-29Cr-6Mo alloy fabricated by selective laser melting process for dental applications.J Mech Behav Biomed Mater. 2013; 21: 67-76
- CAD/CAM imaging in dentistry.Curr Opin Dent. 1991; 1: 150-154
- Direct selective laser sintering of metals.Rapid Prototyp J. 1995; 1: 26-36
- Marginal and internal fit of metal-ceramic crowns fabricated with a new laser melting technology.Dent Mater. 2008; 24: 1311-1315
- The marginal fit of selective laser melting-fabricated metal crowns: an in vitro study.J Prosthet Dent. 2014; 112: 1437-1440
- Selective laser melting of biocompatible metals for rapid manufacturing of medical parts.Rapid Prototyp J. 2007; 13: 196-203
- A comparative analysis of intraoral 3d digital scanners for restorative dentistry.Internet J Med Technol [Internet]. 2011; 5: 1-18
- Intraoral scanners in dentistry: a review of the current literature.BMC Oral Health. 2017; 17: 149
- Clinical evaluation of CAD/CAM metal-ceramic posterior crowns fabricated from intraoral digital impressions.Int J Prosthodont. 2014; 27: 331-337
- CAD/CAM technology for implant abutments, crowns, and superstructures.Int J Oral Maxillofac Implants. 2014; 29 Suppl: 117-136
- Marginal fit consistency of copy-milled all-ceramic crowns during fabrication by light and scanning electron microscopic analysis in vitro.J Oral Rehabil. 1997; 24: 871-881
- Marginal accuracy and internal fit of 3-D printing laser-sintered Co-Cr alloy copings.Materials. 2017; 10: 1-13
- Thermal distortion of different materials in crown construction.J Prosthet Dent. 1994; 72: 360-366
- Influence of the veneering process on the marginal fit of zirconia fixed dental prostheses.J Oral Rehabil. 2010; 37: 283-291
- Different CAD/CAM-processing routes for zirconia restorations: influence on fitting accuracy.Clin Oral Investig. 2011; 15: 527-536
- Marginal adaptation of three different zirconium dioxide three-unit fixed dental prostheses.J Prosthet Dent. 2009; 101: 239-247
- An in vitro evaluation of fit of zirconium-oxide-based ceramic four-unit fixed partial dentures, generated with three different CAD/CAM systems, before and after porcelain firing cycles and after glaze cycles.J Prosthodont. 2008; 17: 621-626
- Comparison of the marginal adaptation of zirconium dioxide crowns in preparations with two different finish lines.J Prosthodont. 2012; 21: 291-295
- Influence of tooth preparation design on fitting accuracy of CAD-CAM based restorations.J Esthet Restor Dent. 2016; 28: 238-246
- Marginal adaptation of castable ceramic crowns.J Prosthet Dent. 1991; 66: 747-753
- Preparation design and margin distortion in porcelain-fused-to-metal restorations.J Prosthet Dent. 1973; 29: 276-284
- Effect of incompatibility stress on the fit of metal-ceramic crowns.J Dent Res. 1987; 66: 1341-1345
- Marginal fit of machine-milled titanium and cast titanium single crowns.Int J Prosthodont. 1994; 7: 440-447
- Marginal fit of electroformed copings before and after the coction of the porcelain.Braz J Oral Sci. 2004; 3: 409-413
- Influence of finish-line geometry on the fit of crowns.Int J Prosthodont. 1993; 6: 25-30
- Effects of firing cycle and surface finishing on distortion of metal ceramic castings.J Prosthet Dent. 1995; 74: 476-481
- Marginal fit changes during porcelain firing cycles.J Prosthet Dent. 1995; 73: 49-54
- A comparison of the marginal fit of In-Ceram, IPS Empress, and Procera crowns.Int J Prosthodont. 1997; 10: 478-484
- Evaluation of the marginal accuracy of different all-ceramic crown systems after simulation in the artificial mouth.J Oral Rehabil. 1999; 26: 582-593
- Five-year clinical results of zirconia frameworks for posterior fixed partial dentures.Int J Prosthodont. 2007; 20: 383-388
- A systematic review of the survival and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years.Clin Oral Implants Res. 2004; 15: 667-676
- An investigation of dental luting cement solubility as a function of the marginal gap.J Prosthet Dent. 1991; 65: 436-442
- The clinical success of all-ceramic restorations.J Am Dent Assoc. 2008; 139 Suppl: 8S-13S
- Periodontal tissue responses after insertion of artificial crowns and fixed partial dentures.J Prosthet Dent. 2000; 84: 492-498
- Effect of in vivo crown margin discrepancies on periodontal health.J Prosthet Dent. 1991; 65: 357-364
- Influence of firing cycles on the margin distortion of 3 all-ceramic crown systems.J Prosthet Dent. 2005; 93: 346-355
- Marginal and internal fits of fixed dental prostheses zirconia retainers.Dent Mater. 2009; 25: 94-102
- The estimation of cement film thickness by an in vivo technique.Br Dent J. 1971; 131: 107-111
- Marginal fit of castable ceramic crowns.J Prosthet Dent. 1992; 67: 594-599
- Considerations in measurement of marginal fit.J Prosthet Dent. 1989; 62: 405-408
- Clinical marginal and internal fit of crowns fabricated using different CAD/CAM technologies.J Prosthodont. 2015; 24: 291-295
- Comparison of marginal fit of Lava CAD/CAM crown-copings with two finish lines.Int J Esthet Dent. 2014; 9: 426-435
Article info
Publication history
Published online: April 01, 2019
Footnotes
The investigators wish to thank the American Academy of Fixed Prosthodontics for their support with a Dr Stanley Tylman Research Grant.
Identification
Copyright
© 2019 by the Editorial Council for The Journal of Prosthetic Dentistry.