Journal of Prosthetic Dentistry
Research and Education| Volume 124, ISSUE 1, P87.e1-87.e6, July 2020

Download started.


Analysis of correlation between optical and microtomography measurements of cementation space in CAD-CAM ceramic crowns


      Statement of problem

      Identical computer-aided design (CAD) parameters may be used to mill a variety of ceramic materials for computer-aided design and computer-aided manufacture (CAD-CAM) crowns. Whether milled crown spacing matches the designed parameters when more than a single evaluation method is applied is unknown.


      The purpose of this in vitro study was to correlate the stereomicroscope and the microcomputer tomography (μCT) 2-dimensional analysis of the cementation space with the replica technique in assessing 3 different ceramic materials.

      Material and methods

      The specimens were milled in lithium disilicate, resin nanoceramic, and zirconia (n=30). The cement space was measured at the marginal, axial, and occlusal regions. One hundred twenty measurements of each material were used to correlate the methodologies. Data were statistically evaluated with 2-way repeated measures ANOVA and the Tukey test (α=.05). The Pearson correlation coefficient was used for each region for both methodologies (μCT and optical microscopy) separately.


      For the μCT analysis, no differences were observed (P>.05) among the materials, but the axial region showed a positive correlation with the marginal (r=0.957) and occlusal regions (r=0.349); the same was observed between the occlusal and marginal regions (r=0.338). However, for stereomicroscope evaluation, resin nanoceramic and zirconia present similar cementation space (P=960), both being different from lithium disilicate (P<.05). The marginal region presented a positive correlation with axial (r=0.149) and occlusal regions (r=0.344), but the axial region showed negative correlation with the occlusal surface (r=−0.205).


      The measurements of the scanned replicas were accurate when thinner sections were under measurement. Although the same space parameters were set in the CAD software program, definitive internal dimensions varied among the milled crowns.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Prosthetic Dentistry
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Tan K.
        • Pjetursson B.E.
        • Lang N.P.
        • Chan E.S.
        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: 654-666
        • Bosch G.
        • Ender A.
        • Mehl A.
        A 3-dimensional accuracy analysis of chairside CAD/CAM milling processes.
        J Prosthet Dent. 2014; 112: 1425-1431
        • Mously H.A.
        • Finkelman M.
        • Zandparsa R.
        • Hirayama H.
        Marginal and internal adaptation of ceramic crown restorations fabricated with CAD/CAM technology and the heat-press technique.
        J Prosthet Dent. 2014; 112: 249-256
        • Lee K.B.
        • Park C.W.
        • Kim K.H.
        • Kwon T.Y.
        Marginal and internal fit of all-ceramic crowns fabricated with two different CAD/CAM systems.
        Dent Mater J. 2008; 27: 422-426
        • Moldovan O.
        • Luthardt R.G.
        • Corcodel N.
        • Rudolph H.
        Three-dimensional fit of CAD/CAM-made zirconia copings.
        Dent Mater. 2011; 27: 1273-1278
        • Molin M.
        • Karlsson S.
        The fit of gold inlays and three ceramic inlay systems. A clinical and in vitro study.
        Acta Odontol Scand. 1993; 51: 201-206
        • May K.B.
        • Russell M.M.
        • Razzoog M.E.
        • Lang B.R.
        Precision of fit: the Procera AllCeram crown.
        J Prosthet Dent. 1998; 80: 394-404
        • Quintas A.F.
        • Oliveira F.
        • Bottino M.A.
        Vertical marginal discrepancy of ceramic copings with different ceramic materials, finish lines, and luting agents: an in vitro evaluation.
        J Prosthet Dent. 2004; 92: 250-257
        • Alfaro D.P.
        • Ruse N.D.
        • Carvalho R.M.
        • Wyatt C.C.
        Assessment of the Internal Fit of Lithium Disilicate Crowns Using Micro-CT.
        J Prosthodont. 2015; 24: 381-386
        • Contrepois M.
        • Soenen A.
        • Bartala M.
        • Laviole O.
        Marginal adaptation of ceramic crowns: a systematic review.
        J Prosthet Dent. 2013; 110: 447-54 e10
        • Kim J.H.
        • Jeong J.H.
        • Lee J.H.
        • Cho H.W.
        Fit of lithium disilicate crowns fabricated from conventional and digital impressions assessed with micro-CT.
        J Prosthet Dent. 2016; 116: 551-557
        • Pimenta M.A.
        • Frasca L.C.
        • Lopes R.
        • Rivaldo E.
        Evaluation of marginal and internal fit of ceramic and metallic crown copings using x-ray microtomography (micro-CT) technology.
        J Prosthet Dent. 2015; 114: 223-228
        • Nawafleh N.A.
        • Mack F.
        • Evans J.
        • Mackay J.
        • Hatamleh M.M.
        Accuracy and reliability of methods to measure marginal adaptation of crowns and FDPs: a literature review.
        J Prosthodont. 2013; 22: 419-428
        • Rahme H.Y.
        • Tehini G.E.
        • Adib S.M.
        • Ardo A.S.
        • Rifai K.T.
        In vitro evaluation of the "replica technique" in the measurement of the fit of Procera crowns.
        J Contemp Dent Pract. 2008; 9: 25-32
        • Reich S.
        • Uhlen S.
        • Gozdowski S.
        • Lohbauer U.
        Measurement of cement thickness under lithium disilicate crowns using an impression material technique.
        Clin Oral Investig. 2011; 15: 521-526
        • Borba M.
        • Cesar P.F.
        • Griggs J.A.
        • Della Bona A.
        Adaptation of all-ceramic fixed partial dentures.
        Dent Mater. 2011; 27: 1119-1126
        • Pelekanos S.
        • Koumanou M.
        • Koutayas S.O.
        • Zinelis S.
        • Eliades G.
        Micro-CT evaluation of the marginal fit of different In-Ceram alumina copings.
        Eur J Esthet Dent. 2009; 4: 278-292
        • Rungruanganunt P.
        • Kelly J.R.
        • Adams D.J.
        Two imaging techniques for 3D quantification of pre-cementation space for CAD/CAM crowns.
        J Dent. 2010; 38: 995-1000
        • Shamseddine L.
        • Mortada R.
        • Rifai K.
        • Chidiac J.J.
        Marginal and internal fit of pressed ceramic crowns made from conventional and computer-aided design and computer-aided manufacturing wax patterns: An in vitro comparison.
        J Prosthet Dent. 2016; 116: 242-248
        • Hung S.H.
        • Purk J.H.
        • Tira D.E.
        • Eick J.D.
        Accuracy of one-step versus two-step putty wash addition silicone impression technique.
        J Prosthet Dent. 1992; 67: 583-589
        • Mai H.N.
        • Lee K.B.
        • Lee D.H.
        Fit of interim crowns fabricated using photopolymer-jetting 3D printing.
        J Prosthet Dent. 2017; 118: 208-215
        • Oka Y.
        • Sasaki J.
        • Wakabayashi K.
        • Nakano Y.
        • Okamura S.Y.
        • Nakamura T.
        • et al.
        Fabrication of a radiopaque fit-testing material to evaluate the three-dimensional accuracy of dental prostheses.
        Dent Mater. 2016; 32: 921-928
        • Boening K.W.
        • Wolf B.H.
        • Schmidt A.E.
        • Kastner K.
        • Walter M.H.
        Clinical fit of Procera AllCeram crowns.
        J Prosthet Dent. 2000; 84: 419-424
        • Dahl B.E.
        • Ronold H.J.
        • Dahl J.E.
        Internal fit of single crowns produced by CAD-CAM and lost-wax metal casting technique assessed by the triple-scan protocol.
        J Prosthet Dent. 2017; 117: 400-404
        • Coli P.
        • Karlsson S.
        Fit of a new pressure-sintered zirconium dioxide coping.
        Int J Prosthodont. 2004; 17: 59-64
        • Wolfart S.
        • Wegner S.M.
        • Al-Halabi A.
        • Kern M.
        Clinical evaluation of marginal fit of a new experimental all-ceramic system before and after cementation.
        Int J Prosthodont. 2003; 16: 587-592
        • Groten M.
        • Girthofer S.
        • Probster L.
        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
        • Falk A.
        • Vult von Steyern P.
        • Fransson H.
        • Thoren M.M.
        Reliability of the impression replica technique.
        Int J Prosthodont. 2015; 28: 179-180
        • Colton T.
        Statistics in medicine.
        1st ed. Little Brown and Company, Boston1974: 209-211