The accuracy of dual-arch impressions: A pilot study

Trevor D. Larson, Mark A. Nielsen, William W. Brackett

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Statement of problem. Dual-arch impression trays often are used for addition silicone final impressions of fixed prosthodontic preparations, but concerns about distortion of the impression are common because such trays lack rigidity. Purpose. This in vitro pilot study was designed to determine the accuracy of addition silicone impressions made with custom trays or made with either passive or stressed dual-arch trays. Material and methods. Complete crown preparations of a mandibular molar, premolar, and incisor were made on a dentoform. These tooth preparations received flat, parallel indexes on the facial and lingual axial walls for accurate and reproducible positioning of a digital caliper. Gypsum dies were produced with an addition silicone impression material in either custom trays or dual-arch trays seated passively or with induced flexure (3 dies per tray group). The facio-lingual dimensions of the dies were measured with a digital caliper accurate to ±5 μm and compared to the dimensions of the original preparations. Flexure in the latter group was induced by contact of the tray with a simulated torus, made of resin, in the lingual vestibule of the dentoform. Data were analyzed with 2-way analysis of variance and Tukey's multiple comparison test (α=.05). Results. Dies fabricated with either the custom or passive dual-arch tray reproduced the facio-lingual dimensions of the preparations within a -27 to +13 μm range. Dies fabricated with the flexed dual-arch tray exhibited greater discrepancy, in the range of -47 to -67 μm relative to the preparations. Tray type was a significant factor (P=.002): the flexed tray group was significantly different than the other 2 groups, which did not differ from each other. Conclusion. Within the limitations of this pilot study, dual-arch impressions were comparable in accuracy to impressions made with custom trays. Accuracy was reduced, however, when the trays were flexed during closure of the arches.

Original languageEnglish (US)
Pages (from-to)625-627
Number of pages3
JournalJournal of Prosthetic Dentistry
Volume87
Issue number6
DOIs
StatePublished - Jan 1 2002

Fingerprint

Tongue
Silicones
Tooth Preparation
Calcium Sulfate
Prosthodontics
Bicuspid
Incisor
Crowns
Analysis of Variance

ASJC Scopus subject areas

  • Oral Surgery

Cite this

The accuracy of dual-arch impressions : A pilot study. / Larson, Trevor D.; Nielsen, Mark A.; Brackett, William W.

In: Journal of Prosthetic Dentistry, Vol. 87, No. 6, 01.01.2002, p. 625-627.

Research output: Contribution to journalArticle

Larson, Trevor D. ; Nielsen, Mark A. ; Brackett, William W. / The accuracy of dual-arch impressions : A pilot study. In: Journal of Prosthetic Dentistry. 2002 ; Vol. 87, No. 6. pp. 625-627.
@article{1354324361aa426b99b2652a385b8b28,
title = "The accuracy of dual-arch impressions: A pilot study",
abstract = "Statement of problem. Dual-arch impression trays often are used for addition silicone final impressions of fixed prosthodontic preparations, but concerns about distortion of the impression are common because such trays lack rigidity. Purpose. This in vitro pilot study was designed to determine the accuracy of addition silicone impressions made with custom trays or made with either passive or stressed dual-arch trays. Material and methods. Complete crown preparations of a mandibular molar, premolar, and incisor were made on a dentoform. These tooth preparations received flat, parallel indexes on the facial and lingual axial walls for accurate and reproducible positioning of a digital caliper. Gypsum dies were produced with an addition silicone impression material in either custom trays or dual-arch trays seated passively or with induced flexure (3 dies per tray group). The facio-lingual dimensions of the dies were measured with a digital caliper accurate to ±5 μm and compared to the dimensions of the original preparations. Flexure in the latter group was induced by contact of the tray with a simulated torus, made of resin, in the lingual vestibule of the dentoform. Data were analyzed with 2-way analysis of variance and Tukey's multiple comparison test (α=.05). Results. Dies fabricated with either the custom or passive dual-arch tray reproduced the facio-lingual dimensions of the preparations within a -27 to +13 μm range. Dies fabricated with the flexed dual-arch tray exhibited greater discrepancy, in the range of -47 to -67 μm relative to the preparations. Tray type was a significant factor (P=.002): the flexed tray group was significantly different than the other 2 groups, which did not differ from each other. Conclusion. Within the limitations of this pilot study, dual-arch impressions were comparable in accuracy to impressions made with custom trays. Accuracy was reduced, however, when the trays were flexed during closure of the arches.",
author = "Larson, {Trevor D.} and Nielsen, {Mark A.} and Brackett, {William W.}",
year = "2002",
month = "1",
day = "1",
doi = "10.1067/mpr.2002.125180",
language = "English (US)",
volume = "87",
pages = "625--627",
journal = "Journal of Prosthetic Dentistry",
issn = "0022-3913",
publisher = "Mosby Inc.",
number = "6",

}

TY - JOUR

T1 - The accuracy of dual-arch impressions

T2 - A pilot study

AU - Larson, Trevor D.

AU - Nielsen, Mark A.

AU - Brackett, William W.

PY - 2002/1/1

Y1 - 2002/1/1

N2 - Statement of problem. Dual-arch impression trays often are used for addition silicone final impressions of fixed prosthodontic preparations, but concerns about distortion of the impression are common because such trays lack rigidity. Purpose. This in vitro pilot study was designed to determine the accuracy of addition silicone impressions made with custom trays or made with either passive or stressed dual-arch trays. Material and methods. Complete crown preparations of a mandibular molar, premolar, and incisor were made on a dentoform. These tooth preparations received flat, parallel indexes on the facial and lingual axial walls for accurate and reproducible positioning of a digital caliper. Gypsum dies were produced with an addition silicone impression material in either custom trays or dual-arch trays seated passively or with induced flexure (3 dies per tray group). The facio-lingual dimensions of the dies were measured with a digital caliper accurate to ±5 μm and compared to the dimensions of the original preparations. Flexure in the latter group was induced by contact of the tray with a simulated torus, made of resin, in the lingual vestibule of the dentoform. Data were analyzed with 2-way analysis of variance and Tukey's multiple comparison test (α=.05). Results. Dies fabricated with either the custom or passive dual-arch tray reproduced the facio-lingual dimensions of the preparations within a -27 to +13 μm range. Dies fabricated with the flexed dual-arch tray exhibited greater discrepancy, in the range of -47 to -67 μm relative to the preparations. Tray type was a significant factor (P=.002): the flexed tray group was significantly different than the other 2 groups, which did not differ from each other. Conclusion. Within the limitations of this pilot study, dual-arch impressions were comparable in accuracy to impressions made with custom trays. Accuracy was reduced, however, when the trays were flexed during closure of the arches.

AB - Statement of problem. Dual-arch impression trays often are used for addition silicone final impressions of fixed prosthodontic preparations, but concerns about distortion of the impression are common because such trays lack rigidity. Purpose. This in vitro pilot study was designed to determine the accuracy of addition silicone impressions made with custom trays or made with either passive or stressed dual-arch trays. Material and methods. Complete crown preparations of a mandibular molar, premolar, and incisor were made on a dentoform. These tooth preparations received flat, parallel indexes on the facial and lingual axial walls for accurate and reproducible positioning of a digital caliper. Gypsum dies were produced with an addition silicone impression material in either custom trays or dual-arch trays seated passively or with induced flexure (3 dies per tray group). The facio-lingual dimensions of the dies were measured with a digital caliper accurate to ±5 μm and compared to the dimensions of the original preparations. Flexure in the latter group was induced by contact of the tray with a simulated torus, made of resin, in the lingual vestibule of the dentoform. Data were analyzed with 2-way analysis of variance and Tukey's multiple comparison test (α=.05). Results. Dies fabricated with either the custom or passive dual-arch tray reproduced the facio-lingual dimensions of the preparations within a -27 to +13 μm range. Dies fabricated with the flexed dual-arch tray exhibited greater discrepancy, in the range of -47 to -67 μm relative to the preparations. Tray type was a significant factor (P=.002): the flexed tray group was significantly different than the other 2 groups, which did not differ from each other. Conclusion. Within the limitations of this pilot study, dual-arch impressions were comparable in accuracy to impressions made with custom trays. Accuracy was reduced, however, when the trays were flexed during closure of the arches.

UR - http://www.scopus.com/inward/record.url?scp=0036598842&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036598842&partnerID=8YFLogxK

U2 - 10.1067/mpr.2002.125180

DO - 10.1067/mpr.2002.125180

M3 - Article

C2 - 12131884

AN - SCOPUS:0036598842

VL - 87

SP - 625

EP - 627

JO - Journal of Prosthetic Dentistry

JF - Journal of Prosthetic Dentistry

SN - 0022-3913

IS - 6

ER -