Effect of impression techniques on soft tissue vertical displacement in removable partial denture. A pilot study
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Vol 13 No 2 (2022), Clinical case
Vol 13 No 2 (2022)

Effect of impression techniques on soft tissue vertical displacement in removable partial denture. A pilot study

Clinical case
Published 29 September 2022
Christine HANNA
DMD, MSc, Clinical instructor, Department of Removable Prosthodontics, School of Dentistry, Saint Joseph University, Beirut, Lebanon
Nada EL OSTA
DMD, MSc, PhD, Clinical Professor, Department of Removable Prosthodontics, School of Dentistry, Saint Joseph University, Beirut, Lebanon
Jihad FAKHOURI
DMD, MSc, PhD, Associate Professor, Department of Removable Prosthodontics, School of Dentistry, Saint Joseph University, Beirut, Lebanon
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Keywords

Vertical tissue displacement
custom tray
alginate
impression techniques
removable partial denture

How to Cite

HANNA, C., EL OSTA, N., & FAKHOURI, J. (2022). Effect of impression techniques on soft tissue vertical displacement in removable partial denture. A pilot study. International Arab Journal of Dentistry (IAJD), 13(2), 104-115. Retrieved from https://journals.usj.edu.lb/iajd/article/view/673
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Abstract

Purpose: The purpose of this study is to evaluate the vertical displacement of soft tissue during different impression procedures using various spacing of the custom tray, and to determine which impression technique would allow the minimal movement.

Materials and Methods: 21 partially edentulous patients were selected and enrolled in the study. Each patient was subjected to four different impression procedures: three alginate impressions with different spacing of the custom tray and one composed with different impression materials, then casts were constructed. Light-curing acrylic occlusal platform was constructed on the primary model and perforated in 10 different points. The plate was positioned on each of the 4 plaster models, then in the mouth; and the distance between the plate and the top of the crest was measured. Each measurement was repeated three times and the mean was recorded. Repeated measures analyses of variance followed by Bonferroni multiple comparisons were conducted to explore the difference among the groups. The alpha error was set at 0.05.  

Results: The mean measurement of the distance between the plate and the top of the crest was significantly different among groups (-p-value <0.001). This distance, which correspond clinically to the vertical tissue displacement, was significantly more important for the models issued from alginate impression with custom tray spaced by one layer of wax (11.351mm), followed by the models issued from two layers of wax (11.155mm), followed by the models issued from three layers of wax (10.987mm) and the results obtained from the two-step impressions (10.824mm) were the closest to the mouth measurements which were significantly the lowest (10.635mm). Therefore, the difference in vertical displacement between the most and the least compressive impressions is approximately 0.527 mm, due to a maximum difference of 0.196 mm between each impression technique respectively. A tissue displacement of 0.716 mm resulted from the most compressive impression, while the least compressive one caused a vertical movement of 0.189 mm.

Conclusion: In conclusion, all the impression techniques caused a vertical displacement of the soft tissues. However, the custom tray with the irreversible hydrocolloid material resulted in a greater amount of movement than the two-step composed technique which showed the minimal displacement, and the compression effect depended on the spacing of the tray. When layers of wax increase, the compressive effect of the impression decreases and measurements become closer to the real measure in mouth. Although statistically significant, the minimal difference between the impression techniques may or may not be clinically relevant. Additional research is needed to assess clinical differences.

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References

1. Allen EP, Bayne SC, Cronin RJ, Donovan TE, Kois JC, Summitt JB, et al. Annual review of selected dental literature: Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry. J Prosthet Dent. 2004 Jul; 92(1):39-71.
2. Douglass CW, Watson AJ. Future needs for fixed and removable partial dentures in the United States. J Prosthet Dent. 2002 Jan;87(1):9-14.
3. Cotmore JM, Mingledorf EB, Pomerantz JM, Grasso JE. Removable partial denture survey: clinical practice today. J Prosthet Dent. 1983 Mar;49(3):321-7.
4. Fokkinga WA, van Uchelen J, Witter DJ, Mulder J, Creugers NHJ. Impression Procedures for Metal Frame Removable Partial Dentures as Applied by General Dental Practitioners. Int J Prosthodont. 2016 Apr;29(2):166-8.
5. Dikbas I, Ozkurt Z, Kazazoglu E. Predoctoral prosthodontic curricula on removable partial dentures: survey of Turkish dental schools. J Dent Educ. 2013 Jan; 77(1):85-92.
6. Petropoulos VC, Rashedi B. Removable partial denture education in U.S. dental schools. J Prosthodont. 2006 Feb; 15(1):62-8.
7. Holmes JB. Influence of impression procedures and occlusal loading on partial denture movement. J Prosthet Dent. 1965 Jun; 15:474-83.
8. Vahidi F. Vertical displacement of distal-extension ridges by different impression techniques. J Prosthet Dent. 1978 Oct; 40(4):374-7.
9. Leupold RJ, Flinton RJ, Pfeifer DL. Comparison of vertical movement occurring during loading of distal-extension removable partial denture bases made by three impression techniques. J Prosthet Dent. 1992 Aug; 68(2):290-3.
10. Madihalli AU, Tavane PN, Yadav NS, Abraham S, Reddy PM, Baiju G. A comparative study of impression procedures for distal extension removable partial dentures. J Contemp Dent Pract. 2011 Sep 1; 12(5):333-8.
11. Maxfield JB, Nicholls JI, Smith DE. The measurement of forces transmitted to abutment teeth of removable partial dentures. J Prosthet Dent. 1979 Feb; 41(2):134-42.
12. Suresh V, SAshishRJ. Comparison of different impression procedures on tissue displacement. International Journal of recent advances in multidisciplinary research. 2015 Mar; 02(03):0340-4.
13. el-Sheikh HA, Abdel-Hakim AM. Sectional impressions for mandibular distal extension removable partial dentures. J Prosthet Dent. 1998 Aug; 80(2):216–9.
14. Frank RP, Brudvik JS, Noonan CJ. Clinical outcome of the altered cast impression procedure compared with use of a one-piece cast. J Prosthet Dent. 2004 May; 91(5):468-76.
15. Kydd WL, Daly CH, Nansen D. Variation in the response to mechanical stress of human soft tissues as related to age. J Prosthet Dent. 1974 Nov; 32(5):493-500.
16. Sayed M, Jain S. Comparison between Altered Cast Impression and Conventional Single-Impression Techniques for Distal Extension Removable Dental Prostheses: A Systematic Review. Int J Prosthodont. 2019 Jun; 32(3):265-71.
17. Lytle RB. Soft tissue displacement beneath removable partial and complete dentures. The Journal of Prosthetic Dentistry. 1962 Jan; 12(1):34-43.
18. Wagle S RS. A clinical study to evaluate and compare theplacement of mucosal tissues in mandibular Kennedy’s class 1situation employing three impression methods and their effecton vertical denture movement. JIDA. 1998; 69:157-60.
19. Picton DC, Wills DJ. Viscoelastic properties of the periodontal ligament and mucous membrane. J Prosthet Dent. 1978 Sep; 40(3):263-72.
20. O’Brien, W. J. Dental materials and their selection. 4th edition. Chicago: Quintessence books; 2008.
21. Inoue K, Song YX, Kamiunten O, Oku J, Terao T, Fujii K. Effect of mixing method on rheological properties of alginate impression materials. J Oral Rehabil. 2002 Jul; 29(7):615-9.
22. Frey G, Lu H, Powers J. Effect of mixing methods on mechanical properties of alginate impression materials. J Prosthodont. 2005 Dec; 14(4):221-5.
23. Owen PC. Appropriatech: prosthodontics for the many, not just for the few. Int J Prosthodont. 2004 Jun; 17(3):261-2.