Inter J Stomatol ›› 2018, Vol. 45 ›› Issue (6): 686-689.doi: 10.7518/gjkq.2018.06.011

• Original Articles • Previous Articles     Next Articles

Comparison of accuracies from different scanned objects of Co-Cr metal porcelain crowns fabricated with com-puter aided design/computer aided manufacture technique

Ying Zhao,Liu Yang,Yu Xie,Yan Zhang,Wei Wei,Jiang Li()   

  1. Dept. of Prosthodontics, Hospital of Stomatology, Jilin University, Changchun 130021, China
  • Received:2018-01-12 Revised:2018-05-03 Online:2018-11-01 Published:2018-11-15
  • Contact: Jiang Li


Objective To evaluate the effects of different scanning objects on the accuracy of computer aided design (CAD)/computer aided manufacture (CAM) Co-Cr metal porcelain crowns.Methods Fifteen Co-Cr metal porcelain crown specimens were fabricated by CAD/CAM technology. According to different scanning objects: prepared teeth, silicone rubber and stone die, they were divided into experimental B groups (group B1, B2, B3). Five specimens of traditional lost wax casting were used as control (group A). Marginal fits (AMD point and MG point) and internal fits (CA point, AW point, AOT point and OA point) were measured by the micro-CT. Statistical analysis was performed via one-way ANOVA and paired-t-test.Results The AMD point’ marginal fits of the experimental B groups were smaller than group A (P<0.05), there was no statistic difference in MG point’ marginal fits between the experimental B groups and group A. The experimental B groups had smaller internal fits than group A except OA point. The internal fits of group B1, 2 were smaller than the group A at AOT, AW and OA points (P<0.05), except group B3 (P>0.05). There was no statistic difference in CA point’ internal fits between the experimental B groups and group A (P>0.05).Conclusion The accuracy of silicone rubber is higher than the prepared tooth and stone die. Comparing to the traditional casting, the CAD/CAM has better marginal and internal fits.

Key words: computer aided design/computer aided manufacture, silicone rubber, Micro-CT, marginal and internal fit

CLC Number: 

  • R783.2


Fig 1

Different measuring points of internal (A) and marginal (B) fits on Micro-CT 2D images"

Fig 2

The changes of marginal and internal fits before and after por-celain firing"

[1] Mously HA, Finkelman M, Zandparsa R , et al. Mar-ginal and internal adaptation of ceramic crown resto-rations fabricated with CAD/CAM technology and the heat-press technique[J]. J Prosthet Dent, 2014,112(2):249-256.
doi: 10.1016/j.prosdent.2014.03.017 pmid: 24795263
[2] Rekow ED . Dental CAD-CAM systems. What is the state of the art[J]. J Am Dent Assoc, 1991,122(12):42-48.
doi: 10.14219/jada.archive.1991.0205 pmid: 1783723
[3] Beuer F, Schweiger J, Edelhoff D . Digital dentistry: an overview of recent developments for CAD/CAM generated restorations[J]. Br Dent J, 2008,204(9):505-511.
doi: 10.1038/sj.bdj.2008.350 pmid: 18469768
[4] Pinheiro Tannure AL, Cunha AG, Borges Junior LA , et al. Wear at the implant-abutment interface of zir-conia abutments manufactured by three CAD/CAM systems[J]. Int J Oral Maxillofac Implants, 2017,32(6):1241-1250.
doi: 10.11607/jomi.5507 pmid: 29140369
[5] Laurent M, Scheer P, Dejou J , et al. Clinical evaluation of the marginal fit of cast crowns—validation of the silicone replica method[J]. J Oral Rehabil, 2008,35(2):116-122.
doi: 10.1111/j.1365-2842.2003.01203.x
[6] Borba M, Cesar PF, Griggs JA , et al. Adaptation of all-ceramic fixed partial dentures[J]. Dent Mater, 2011,27(11):1119-1126.
doi: 10.1016/ pmid: 21920595
[7] Felton DA, Kanoy BE, Bayne SC , et al. Effect of in vivo crown margin discrepancies on periodontal health[J]. J Prosthet Dent, 1991,65(3):357-364.
doi: 10.1016/0022-3913(91)90225-L pmid: 2056454
[8] Kocaağaoğlu H, Albayrak H, Kilinc HI , et al. Effect of repeated ceramic firings on the marginal and inte- rnal adaptation of metal-ceramic restorations fabricated with different CAD-CAM technologies[J]. J Prosthet Dent, 2017,118(5):672-677.
[9] Patil A, Singh K, Sahoo S , et al. Comparative assess-ment of marginal accuracy of grade Ⅱ titanium and Ni-Cr alloy before and after ceramic firing: an in vitro study[J]. Eur J Dent, 2013,7(3):272-277.
doi: 10.4103/1305-7456.115409
[10] Fleming PS, Marinho V, Johal A . Orthodontic mea-surements on digital study models compared with plaster models: a systematic review[J]. Orthod Cra-niofac Res, 2011,14(1):1-16.
doi: 10.1111/j.1601-6343.2010.01503.x pmid: 21205164
[11] Seelbach P, Brueckel C, Wöstmann B . Accuracy of digital and conventional impression techniques and workflow[J]. Clin Oral Investig, 2013,17(7):1759-1764.
doi: 10.1007/s00784-012-0864-4 pmid: 23086333
[12] Zaruba M, Mehl A . Chairside systems: a current review[J]. Int J Comput Dent, 2017,20(2):123-149.
pmid: 28630955
[13] Miyazaki T, Hotta Y, Kunii J , et al. A review of dental CAD/CAM: current status and future perspectives from 20 years of experience[J]. Dent Mater J, 2009,28(1):44-56.
doi: 10.4012/dmj.28.44 pmid: 19280967
[14] Jörgensen KD . A new method of recording the elastic recovery of dental impression materials[J]. Scand J Dent Res, 1976,84(3):175-182.
doi: 10.1111/j.1600-0722.1976.tb00476.x pmid: 1064127
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