A 3-dimensional accuracy analysis of chairside CAD/CAM milling processes

Bosch, Gabriel; Ender, Andreas; Mehl, Albert

doi:10.1016/j.prosdent.2014.05.012

Cited by 122 publications

(115 citation statements)

References 29 publications

(34 reference statements)

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“…A physical stone cast is not necessary but can be produced using rapid prototyping technology. 31 However, the accuracy of digital impression for different clinical applications is controversial, even though several studies show that digital and conventional impressions produce restorations of equal quality. 2,21,22,26 The conventional linear distance measurement is limited to certain geometric forms.…”

Section: Introductionmentioning

confidence: 99%

In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions

Ender

Attin

Mehl

2016

The Journal of Prosthetic Dentistry

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STATEMENT OF PROBLEM: Digital impression systems have undergone significant development in recent years, but few studies have investigated the accuracy of the technique in vivo, particularly compared with conventional impression techniques. PURPOSE: The purpose of this in vivo study was to investigate the precision of conventional and digital methods for complete-arch impressions. MA-TERIAL AND METHODS: Complete-arch impressions were obtained using 5 conventional (polyether, POE; vinylsiloxanether, VSE; direct scannable vinylsiloxanether, VSES; digitized scannable vinylsiloxanether, VSES-D; and irreversible hydrocolloid, ALG) and 7 digital (CEREC Bluecam, CER; CEREC Omnicam, OC; Cadent iTero, ITE; Lava COS, LAV; Lava True Definition Scanner, T-Def; 3Shape Trios, TRI; and 3Shape Trios Color, TRC) techniques. Impressions were made 3 times each in 5 participants (n=15). The impressions were then compared within and between the test groups. The cast surfaces were measured point-to-point using the signed nearest neighbor method. Precision was calculated from the (90%-10%)/2 percentile value. RESULTS: The precision ranged from 12.3 m (VSE) to 167.2 m (ALG), with the highest precision in the VSE and VSES groups. The deviation pattern varied distinctly according to the impression method. Conventional impressions showed the highest accuracy across the complete dental arch in all groups, except for the ALG group. CONCLUSIONS: Conventional and digital impression methods differ significantly in the complete-arch accuracy. Digital impression systems had higher local deviations within the complete arch cast; however, they achieve equal and higher precision than some conventional impression materials. techniques. Impressions were made 3 times each in 5 participants (n = 15). The impressions were then compared within and between the test groups. The cast surfaces were measured point-to-point using the signed nearest neighbor method. Precision was calculated from the (90%-10%)/2 percentile value.Results. The precision ranged from 12.3 µm (VSE) to 167.2 µm (ALG), with the highest precision in the VSE and VSES groups. The deviation pattern varied distinctly according to the impression method. Conventional impressions showed the highest accuracy across the complete dental arch in all groups, except for the ALG group.Conclusions. Conventional and digital impression methods differ significantly in the complete-arch accuracy. Digital impression systems had higher local deviations within the 2 complete arch cast; however, they achieve equal and higher precision than some conventional impression materials. CLINICAL IMPLICATIONSThe accuracy of complete-arch impression casts differs significantly between conventional techniques and digital impression systems. Local deviations are greater in casts generated using digital impression systems; however, digital systems show adequate accuracy across the complete arch. As digital impression systems continue to improve, they may prove to be an equivalent or better alternative to convent...

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Section: Introductionmentioning

confidence: 99%

In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions

Ender

Attin

Mehl

2016

The Journal of Prosthetic Dentistry

Self Cite

389

437

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“…[8][9][10][11][12][13][14][15] A recent systematic review assessed the results of the marginal fit for crowns fabricated with 17 different fabrication processes. 16 The analysis revealed a wide range in the results.…”

Section: Introductionmentioning

confidence: 99%

“…This finding is in accordance with the results of a recent in vitro study which investigated the influence of different milling processes on the fit of ceramic restorations. 13 In this study, partial crowns were milled by using a 4-axial and a 5-axial milling unit. The accuracy of the restorations was assessed by means of 3D scanning and by superimposing the digital data sets.…”

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confidence: 99%

Randomized controlled within-subject evaluation of digital and conventional workflows for the fabrication of lithium disilicate single crowns. Part III: marginal and internal fit

Zeltner

Sailer

Mühlemann

et al. 2017

The Journal of Prosthetic Dentistry

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STATEMENT OF PROBLEM Trials comparing the overall performance of digital with that of conventional workflows in restorative dentistry are needed. PURPOSE The purpose of the third part of a series of investigations was to test whether the marginal and internal fit of monolithic crowns fabricated with fully digital workflows differed from that of crowns fabricated with the conventional workflow. MATERIAL AND METHODS In each of 10 participants, 5 monolithic lithium disilicate crowns were fabricated for the same abutment tooth according to a randomly generated sequence. Digital workflows were applied for the fabrication of 4 crowns using the Lava, iTero, Cerec inLab, and Cerec infinident systems. The conventional workflow included a polyvinyl siloxane impression, manual waxing, and heat-press technique. The discrepancy between the crown and the tooth was registered using the replica technique with polyvinyl siloxane material. The dimensions of the marginal discrepancy (Discrepancymarginal) and the internal discrepancy in 4 different regions of interest (Discrepancyshoulder, Discrepancyaxial, Discrepancycusp, and Discrepancyocclusal) were assessed using light microscopy. Post hoc Student t test with Bonferroni correction was applied to detect differences (=.05). RESULTS Discrepancymarginal was 83.6 ±51.1 m for the Cerec infinident, 90.4 ±66.1 m for the conventional, 94.3 ±58.3 m for the Lava, 127.8 ±58.3 m for the iTero, and 141.5 ±106.2 m for the Cerec inLab workflow. The differences between the treatment modalities were not statistically significant (P>.05). Discrepancyshoulder was 82.2 ±42.4 m for the Cerec infinident, 97.2 ±63.8 m for the conventional, 103.4 ±52.0 m for the Lava, 133.5 ±73.0 m for the iTero, and 140.0 ±86.6 m for the Cerec inLab workflow. Only the differences between the Cerec infinident and the Cerec inLab were statistically significant (P=.036). The conventionally fabricated crowns revealed significantly lower values in Discrepancycusp and Discrepancyocclusal than all the crowns fabricated with digital workflows (P<.05). CONCLUSIONS In terms of marginal crown fit, no significant differences were found between the conventional and digital workflows for the fabrication of monolithic lithium disilicate crowns. In the occlusal regions, the conventionally manufactured crowns revealed better fit than the digitally fabricated crowns. Chairside milling resulted in less favorable crown fit than centralized milling production. Purpose. The purpose of the fourth part of a series of investigations was to test whether the marginal and internal fit of monolithic crowns fabricated with fully digital workflows differed from that of crowns fabricated with the conventional workflow. Material and methods.In each of 10 participants, 5 monolithic lithium disilicate crowns were fabricated for the same abutment tooth according to a randomly generated sequence.Digital workflows were applied for the fabrication of 4 crowns with Lava, iTero, Cerec inLab, and Cerec infinident systems. The conventional workflow ...

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“…If milling is performed with adequate accuracy, these disadvantages can be avoided. Another benefit of accurate milling is the reduced need for adaptation at internal surfaces [17], which saves time. Furthermore, by reducing the need for manual finishing steps [3] at internal and occlusal surfaces, artificial material damage can be avoided and the quality of the restoration can be improved [18].…”

Section: Introductionmentioning

confidence: 99%

“…To date, few studies have directly examined this kind of milling accuracy [17]. In the study mentioned before, surfaces of the virtual and milled restoration were directly compared and all milled surfaces, in particular, the inner and occlusal surface, were evaluated.…”

Section: Introductionmentioning

confidence: 99%