Confounding Factors Affecting the Marginal Quality of an Intra-Oral Scan

Article English OPEN
Keeling, A ; Wu, J ; Ferrari, M (2017)
  • Publisher: Elsevier
  • Subject:
    mesheuropmc: stomatognathic diseases | stomatognathic system

Objectives: To assess the effect of clinical factors on the quality of intra-oral scans of crown margins. These factors are; presence of adjacent teeth, proximity to gingivae, encumbrance of wand positioning within oral cavity. Methods: A typodont lower molar (Frasaco, Germany) was prepared for an all-ceramic crown with 1.5 mm supraginigival (lingual) and equigingival (buccal) margins. The tooth was scanned in a model scanner, creating a master scan. An intra-oral scanner (IOS) (Omnicam, Sirona Dental) was used to acquire sets of 5 scans each, under varying conditions; (1) the presence/absence of adjacent teeth, (2) model mounted in manikin head/hand-held, (3) with/without a 1 mm shim to elevate the margin. Every combination was investigated, yielding 40 scans (8 groups of 5). The master scan margin was identified by selecting the highest curvature region (>1.8). The master was aligned to each IOS scan, and 4 regions of each IOS scan margin were extracted, lying within 100 μm of predefined mesial, distal, buccal and lingual sections of the master margin. The mean curvature of each margin section was calculated using Meshlab. The effect of each confounding factor on margin curvature was analysed using ANOVA. Results: Lingual margin curvature remained consistent regardless of scanning conditions. Buccal margin curvature was significantly affected when located equigingivally. Mesial margin curvature was significantly affected in the presence of adjacent teeth and proximity to the gingivae. Distal margin curvature was significantly affected by all three confounding factors. Conclusions: The curvature (sharpness) of the margin recorded by a commercial IOS is significantly affected by clinical factors obscuring visibility.
  • References (18)
    18 references, page 1 of 2

    [1] A. Podhorsky, P. Rehmann, B. Wostmann, Tooth preparation for full-coverage restorations - a literature review, Clin. Oral Investig. 19 (2015) 959 968.

    [2] S. Morimoto, F.B.W. Rebello de Sampaio, M.M. Braga, N. Sesma, M. Ozcan, Survival Rate of Resin and Ceramic Inlays, Onlays, and Overlays: A Systematic Review and Meta-analysis., J. Dent. Res. 95 (2016) 985 994.

    [3] P.K. Brawek, S. Wolfart, L. Endres, A. Kirsten, S. Reich, The clinical accuracy of single crowns exclusively fabricated by digital workflow-the comparison of two systems, Clin. Oral Investig. 17 (2013) 2119 2125.

    [4] S. Reich, S. Uhlen, S. Gozdowski, U. Lohbauer, Measurement of cement thickness under lithium disilicate crowns using an impression material technique, Clin. Oral Investig. 15 (2011) 521 526.

    [5] J.R. Holmes, S.C. Bayne, G.A. Holland, W.D. Sulik, Considerations in measurement of marginal fit, J. Prosthet. Dent. 62 (1989) 405 408.

    [6] J.R. Holmes, W.D. Sulik, G.A. Holland, S.C. Bayne, Marginal fit of castable ceramic crowns, J. Prosthet. Dent. 67 (1992) 594 599.

    W.H. Mörmann, The evolution of the CEREC system., J. Am. Dent. Assoc. 137 Suppl (2006) [8] A. Ender, A. Mehl, Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision, J. Prosthet. Dent. 109 (2013) 121 128.

    [9] P study, Int. J. Comput. Dent. 14 (2011) 11 21. al impressions an in-vitro [10] A. Ender, T. Attin, A. Mehl, In vivo precision of conventional and digital methods of obtaining complete-arch dental impressions, J. Prosthet. Dent. 115 (2016) 313 320.

    [11] M. Boeddinghaus, E.S. Breloer, P. Rehmann, B. Wostmann, Accuracy of single-tooth restorations based on intraoral digital and conventional impressions in patients, Clin. Oral Investig. 19 (2015).

    [12] B. Wöstmann, P. Rehmann, M. Balkenhol, Accuracy of impressions obtained with dual-arch trays, Int. J. Prosthodont. 22 (2009) 158 160.

  • Metrics
    views in OpenAIRE
    views in local repository
    downloads in local repository

    The information is available from the following content providers:

    From Number Of Views Number Of Downloads
    White Rose Research Online - IRUS-UK 0 11
Share - Bookmark