Skip to main content
NCBI home page
Journal of International Society of Preventive & Community Dentistry logoLink to Journal of International Society of Preventive & Community Dentistry
. 2024 Jun 27;14(3):252–259. doi: 10.4103/jispcd.jispcd_165_23

A Newly Formulated Vinyl Polysiloxane Impression Material with Improved Mechanical Properties

Long Ling 1,✉, Theresa Lai 1, Raj Malyala 1
PMCID: PMC11268533  PMID: 39055300

ABSTRACT

Aim:

To evaluate the mechanical properties of a newly formulated vinyl polysiloxane (VPS) impression material.

Materials and Methods:

Experimental, Capture (S&C Polymer), Express, Imprint 3 and Imprint 4 (3M ESPE), Start VPS (Danville), Honigum (DMG), Virtual (Ivoclar Vivadent), Elite HD+ (Zhermack) were evaluated for tear strength, tensile strength, and elongation at break. Un-nicked specimens with a 90° angle on one side (type C) for tear strength were prepared and tested according to ASTM-D624. Dumbbell-shaped specimens (type 1) for tensile strength and elongation at break were prepared and tested according to ISO 37. All tests were carried out at 500 mm/min on a Shimadzu (AGS-X-10 KN-table top) tester. A one-way analysis of variance (ANOVA) was used to analyze the data.

Results:

Experimental material showed significantly higher or higher tear strength and elongation at break compared to other impression materials for both light body (LB) and heavy body (HB). For tensile strength, Experimental is similar to most impression materials; however, significantly lower than Imprint 3 and Start VPS for LB. This parameter for HB is higher or significantly higher than other impression materials except Start VPS. Tear strength and tensile strength were not correlated for LB but have a weak or moderate correlation for HB. Elongation at break is inversely proportional to tensile strength moderately for LB; however, there is no or very weak relation for HB.

Conclusions:

Experimental VPS impression material demonstrated a significantly higher tear strength and adequate tensile strength with higher elongation compared to other commercially available VPS impression materials. Adequate mechanical properties can provide accurate impressions for successful clinical fabrication of restorations. Experimental VPS impression material is suitable for use in dental impressions for fabrication of restorations.

Keywords: Elongation, mechanical properties, tear strength, tensile strength, vinyl polysiloxane (VPS), VPS impression material

INTRODUCTION

Impression is an important step in dentistry for the successful fabrication of restorations such as crowns, fixed partial dentures, or removable prostheses.[1,2,3,4] The successful fabrication of restorations mainly depends on the accurate impression, which was formed from a precise replica of the intraoral structure (the tooth structure and the soft tissue surrounding it).[5,6] Although digital impression has gained great interest and some progress has been made in recent years,[7] adopting digitization is still costly and may take much longer time to significantly unfold; therefore, most clinicians continue to use a lot of different impression materials,[8] and major companies and some researchers continue to improve some properties of impression materials and to invent novel impression materials.[9,10,11,12,13,14] This can be evidenced by the consumption of impression materials in the US market. According to IData research, the total value of the impression materials market in the U.S. exceeded $245 million in 2016 and will be $262.4 million in 2023.[15] There exists a variety of impression materials in the market for clinicians to take dental impressions. The most used dental impression materials are vinyl polysiloxane (VPS, 71.5% in 2016 and 74.6% estimated in 2023), polyether (PE, 20% in 2016 and 17.9% estimated in 2023), and alginate (5% in 2016 and 3.3% estimated in 2023).[15,16] VPS impression materials have captured the majority of the impression material market due to their precise detail reproduction, excellent dimensional stability, and good recovery from deformation.[15,16,17,18]

To obtain an accurate impression and a successful clinical outcome, an impression material must have adequate mechanical properties, such as tear strength, tensile strength, and elongation, because adequate mechanical properties ensure that the impression material can withstand stress under various situations without tearing and permanent deformation during removal from the mouth.[19,20,21,22] During impression removal and cast separation from the set impression, an impression material is susceptible to tearing in gingival crevices and interproximal areas, which causes defects or even rupture and finally affects the accuracy of the final restoration.[18] In addition, if an impression material does not have sufficient elasticity or ductility (too rigid), the impression material causes/becomes permanent deformation when distorted beyond its elastic range, which hinders its removal from the soft tissue undercuts and increases the possibility of die breakage once removed from the stone die.[6] Therefore, favorable mechanical properties are critical for achieving accurate impressions and the successful fabrication of restorations. It is highly desirable for the impression material to have high tear strength and high elongation.

The aim of this research is to assess the mechanical properties of a new VPS impression material and compare it with other commercially available VPS impression materials. The hypothesis is that the new VPS impression material has high tear strength, high elongation at break, and adequate tensile strength compared to the commercially available VPS impression materials.

MATERIALS AND METHODS

MATERIALS

Experimental impression material was prepared based on our resin-based composite technology, which included vinyl polydimethylsiloxanes, polymethyl hydrogen siloxane, surfactant, organoplatinum complex catalysts, and fillers. All resin monomers and additives were mixed with an overhead stirrer (IKA RW20 digital, Wilmington/NC, USA) for at least 3 h. to form a homogeneous resin. The resulting resin mixtures were further mixed with fillers via a speed mixer (Hauschild, DAC 150.1, Hamm, Germany) for at least 2 h. until a uniform flowable paste was produced for both the base and catalyst pastes, respectively. Eight commercially available VPS impression materials, including Capture (S&C Polymer, Elmshorn, Germany), Express, Imprint 3 and Imprint 4 (3M ESPE, St. Paul, Minnesota), Start VPS (Danville, Anaheim, California), Honigum (DMG, Hamburg, Germany), Virtual (Ivoclar Vivadent, Schaan, Liechtenstein), and Elite HD+ (Zhermack, Badia Polesine (RO), Italy), were selected for comparison [Table 1].

Table 1.

VPS impression materials used in this study

Materials Manufacturer Type (ISO-4823) Composition
Exp. Glidewell 3-LB, 1-HB Vinyl polydimethylsiloxane, polymethyl hydrogensiloxane, surfactant, organoplatinic complex, fumed silica, wollastonite, cristobalite
Capture S&C Polymer 3-LB, 1-HB Polydimethyl polymethyl vinyl siloxane, polydimethyl polymethyl hydrogen siloxane, silica, paraffin
Express 3M ESPE 3-LB, 1-HB Vinyl polydimethylsiloxane, dimethyl methyl hydrogen silicone, poly(dimethylsiloxane), quartz silica, silane-treated silica, c.i. pigment blue 28
Imprint 3 3M ESPE 3-LB, 1-HB Vinyl polydimethylsiloxane, dimethyl methyl hydrogen silicone, glycols, polyethylene, methyl 3-[1,3,3,3-tetramethyl-1-(trimethylsiloxy) disiloxanyl]propyl ether, silane-treated silica, cristobalite, quartz silica
Imprint 4 3M ESPE 3-LB, 1-HB Vinyl polydimethylsiloxane, poly(dimethylsiloxane), silane-treated silica, cristobalite
StartVPS Danville 3-LB, 1-HB Polydimethylsiloxane, silica, and paraffin
Honigum DMG 3-LB, 1-HB Polyvinyl siloxane, platinum catalyst, silicon-dioxide-based fillers, additives, pigments
Virtual Ivoclar Vivadent 3-LB, 1-HB Vinylpolysiloxane, methyl hydrogen siloxane, silica, organoplatinic complex and food dyes
Elite HD+ Zhermack 3-LB, 1-HB Alkyl phenol polyethylene glycol ether, quartz, cristobalite
Open in a new tab
*

LB = light body, HB = heavy body

TEAR STRENGTH

Un-nicked specimens with a 90° angle on one side and with tab ends (type C-right angle, n = 5) were prepared, gripped symmetrically at 15 mm away from each end, and stretched at 500 mm/min until they broke using a Shimadzu (AGS-X-10 KN-table top) tester in accordance with ASTM-D624.

Tear strength (Ts) was calculated as follows:

Ts = F/d

where F = the maximum force in Newton, d = the median thickness of the sample in millimeters (measured at three places across the right angle and the end of each sample).

TENSILE STRENGTH AND ELONGATION AT BREAK

The specimens (type 1, n = 5) for tensile strength and elongation at break were prepared and tested at 500 mm/min on a Shimadzu (AGS-X-10 KN-table top) tester in accordance with ISO 37. The test length was 25 ± 0.5 mm. Tensile strength (TS or σ) was calculated using the following formula:

σ = Fm/Wt

where Fm = the maximum force recorded in Newton, W = the mean width of the narrow portion of the sample in millimeters, t = the mean thickness of the test length of the sample in millimeters.

Elongation at break (Eb or ε) as a percentage was expressed as follows:

ε = (ΔL/L) × 100

where ΔL is increased length, and L is the initial test length.

Examples of specimens and testing on a Shimadzu (AGS-X-10 KN-table top) tester for tear strength and tensile strength are shown in Figures 1 and 2.

Figure 1.

Figure 1

Open in a new tab

Examples of specimens for tear strength (left) and tensile strength (right)

Figure 2.

Figure 2

Open in a new tab

Example of a specimen loaded and failed on a Shimadzu universal testing machine

STATISTICAL ANALYSIS

Minitab 18 Statistical Software (Minitab, LLC., State College, Pennsylvania) was employed to do statistical analysis for all obtained results. A one-way ANOVA (P = 0.05) was used to analyze the mean values for tear strength, tensile strength, and elongation at break, respectively, followed by Tukey’s post hoc comparison (P = 0.05). The relationships between tear strength and tensile strength and between tensile strength and elongation at break were characterized by Pearson correlation coefficient (R).

RESULTS

Experimental material showed significantly higher tear strength and elongation at break compared to other impression materials for both light body (LB) and heavy body (HB) (P < 0.001) [Figures 3 and 4]. For tensile strength, Experimental is similar to most impression materials (Elite HD+, Express, Honigum, Virtual, etc., P > 0.05) but significantly lower than Imprint 3 and Start VPS for LB (P < 0.001) [Figure 5]. The tensile strength of Experimental HB is slightly or significantly higher than that of other impression materials (P > 0.05 or P < 0.001) except for Start VPS [Figure 5].

Figure 3.

Figure 3

Open in a new tab

Tear strength of VPS impression materials (*Value bars with the different letters are statistically different between the tested groups)

Figure 4.

Figure 4

Open in a new tab

Elongation at break of VPS impression materials (*Value bars with the different letters are statistically different between the tested groups)

Figure 5.

Figure 5

Open in a new tab

Tensile strength of VPS impression materials (*Value bars with the different letters are statistically different between the tested groups)

Pearson’s correlations for tear strength and tensile strength, and tensile strength and elongation at break, are shown in Figures 6,7,8,9. Based on Evans’ and Moore’s guides,[23,24] no or very weak correlation for light bodies (Pearson’s correlation coefficient R = 0.0775) and a weak or moderate correlation for heavy bodies (R = 0.4651) was observed between tear strength and tensile strength, and a moderate correlation (R = 0.5428) for light bodies and very weak or no correlation (R = 0.1162) for heavy bodies were found between tensile strength and elongation at break.

Figure 6.

Figure 6

Open in a new tab

Correlation of tear strength and tensile strength of VPS impression materials (light bodies)

Figure 7.

Figure 7

Open in a new tab

Correlation of tear strength and tensile strength of VPS impression materials (heavy bodies)

Figure 8.

Figure 8

Open in a new tab

Correlation of tensile strength and elongation of VPS impression materials (light bodies)

Figure 9.

Figure 9

Open in a new tab

Correlation of tensile strength and elongation of VPS impression materials (heavy bodies)

DISCUSSION

Tear strength is an essential mechanical property for the impression material to resist tearing during impression removal. Tear strength is the capability of the material to resist tearing under tensile stress, which was determined using a right angle (type C) according to ASTM-D624. Experimental exhibited significantly higher or higher tear strength than other impression materials for both LB and HB (P < 0.001).

During impression removal from the mouth, tensile stress is applied. Impressions should not only resist tearing but also have adequate tensile resistance and sufficient elongation for elastic recovery. Tensile strength is the maximum stress that a material can withstand while being stretched or pulled before breaking, which was determined according to ISO 37 (type 1). It is reported that impression materials are subjected to both compressive and tensile forces;[25] however, the maximum tensile removal stress of impression materials is greater than the maximum compressive seating force,[26] especially when the impression materials are pulled from undercut and interproximal areas.[27]

Elongation at break is a material’s resistance to breaking when stretched, which indicates how much a material can elastically and plastically deform before failure. Soft elastic materials can deform several times their own length before breaking and typically feature a higher elongation at break. Therefore, a high elongation is desired, especially for the light bodies when impression materials are pulled from undercuts and interproximal areas and stretched in tension. For LB impression materials, Experimental showed tensile strength slightly lower than or similar to most of the impression materials (P > 0.05) but significantly lower than Imprint 3 and Start VPS (P < 0.001). For HB impression materials, Experimental has slightly or significantly higher tensile strength than other impression materials (P > 0.05 or P < 0.001) except Start VPS. Experimental showed significantly higher elongation at break than other impression materials for both LB and heavy bodies (P < 0.001).

The abovementioned different mechanical properties between Experimental and other impression materials resulted mainly from the differences in the chemical composition (resins, catalysts, additives, and fillers) and viscosity of impression materials, and so on.[21,28,29,30,31] Most commercially available VPS impression materials used one or two or more vinyl polydimethylsiloxanes as curable resins and one or two or more silica powders as fillers such as cristobalite and quartz [Table 1], along with some additives such as surfactant. As vinyl polydimethylsiloxane is a base prepolymer for addition-curing room temperature vulcanization (RTV), the actual vinyl polydimethylsiloxanes used by different manufacturers may be different due to the difference in structure, vinyl content, molecular weight, and viscosity, for example, vinyl polydimethylsiloxanes from Gelest and Evonik. Even for the same manufacturer like Evonik, vinyl polydimethylsiloxane resins with the same viscosity from different series have different vinyl content; for example, VQM 900 series has a higher vinyl content compared to the Polymer VS series.[32,33] Catalysts and some additives have similar situations to resins. A variety of inorganic fillers may be employed, such as silica and metallic oxides, to provide the impression materials with adequate strength because unfilled impression materials have extremely poor mechanical properties. The composition, loading, particle size, and distribution of the filler have a crucial impact on the mechanical properties. Experimental impression material was made by our resin and filler composite technology, which was based on multiple vinyl polydimethylsiloxane resins with different vinyl content (0.04–0.43 wt.%), molecular weight (17,200–117,000 g/mol), and viscosity (200–60,000 cSt), and on combination of three silica fillers (fumed silica, wollastonite, and cristobalite) with consideration of good balance of mechanical strength and other properties such as viscosity. Therefore, the optimal formula, like ratios of different polydimethylsiloxane resins, and of three silica fillers and ratio of resins and fillers, can meet the consistency/viscosity requirement required by ISO-4823 and provide improved mechanical properties. As manufacturers provided limited information for the compositions, it is hard to obtain detailed information about the resins and fillers used and to compare the composition differences for these impression materials.

Clearly, the heavy bodies of impression materials have significantly higher (P < 0.05, or <0.001) or higher (P > 0.05) tear strength and significantly lower (P ≤ 0.001) elongation at break compared to their corresponding LB impression materials, which were mainly contributed by their viscosity [heavy bodies (type 1) have higher viscosity than light bodies (type 3) based on ISO-4823 classification], depending on their composition (filler loading and properties, resins, etc.).[20,21,30] But, in terms of tensile strength, some impression materials showed no significant difference between LB and HB of the same impression materials (P > 0.05), such as Imprint 3, Imprint 4, Start VPS, Honigum, and Virtual; others showed significant difference between light bodies and heavy bodies (P < 0.05 but close to 0.05), such as Experimental, Capture, Express, and Elite HD+, which indicated that the viscosity influence from LB to HB on tensile strength is not remarkable as on tear strength and elongation at break. Although HB has higher tear strength than LB, LB is typically applied in the interproximal/subgingival areas where the impression is most likely torn; therefore, the tear property of LB impression materials is more clinically relevant.[20]

Tear strength and tensile strength are crucial properties for impression materials; however, to the best of the authors’ knowledge, there is little information on the relationships between tear strength and tensile strength and tensile strength and elongation at break for impression materials. Based on all impression materials tested, there are very weak or no correlations between tear strength and tensile strength for light bodies (Pearson’s correlation coefficient R = 0.0775) and a weak or moderate correlation for heavy bodies (R = 0.4651) according to what Evans and Moore suggested.[23,24] The correlation between tear strength and tensile strength of light bodies is similar to the results that tear strength was not correlated with tensile strength by Lu et al.[20] (R = −0.033) and Pandey et al.[21] (R = −0.056). However, the results of Lu et al.[20] and Pandey et al.[21] are based on only three impression materials that belong to different types of impression materials (VPS, PE, and polyvinyl ether silicone), yet their results are probably based on both LB and heavy bodies. A moderate correlation between tensile strength and elongation at break was found for light bodies (R = 0.5428); that is, elongation at break is moderately inversely proportional to tensile strength for LB impression materials tested in this study. This is consistent with a study by Wu et al.[34] However, heavy bodies only showed a very weak or no correlation (R = 0.1162) between tensile strength and elongation at break. The degree of correlation between tensile strength and elongation depends on material categorization or type (such as vinyl polysiloxane or PE, LB, or HB under the same category) and composition (such as filler loading).[16,17,35,36]

This study investigated three major mechanical properties of a newly formulated VPS and eight other commercially available VPS impression materials to ensure that the impression materials can withstand stress under various situations and have an accurate impression for restoration. However, this study did not consider other properties like hydrophilicity, dimensional accuracy, and stability, which also affect the accuracy impression. Future work on other properties like hydrophilicity and dimensional accuracy is ongoing and will be reported later.

CONCLUSIONS

The Glidewell Exp VPS impression material exhibited a significantly higher tear strength and adequate tensile strength with higher elongation at break compared to other commercially available VPS impression materials. Based on all impression materials tested, there is a very weak or no correlation for light bodies and a weak or moderate correlation for heavy bodies between tear strength and tensile strength. A moderate correlation on light bodies and a very weak or no correlation on heavy bodies was observed between tensile strength and elongation at break.

FINANCIAL SUPPORT AND SPONSORSHIP

This study did not receive any external funding.

CONFLICTS OF INTEREST

The authors declare no conflicts of interest.

AUTHORS CONTRIBUTIONS

LL: Conceptualization, methodology, writing—original draft preparation, writing—review and editing, formal analysis, investigation, data curation; TL: investigation, data curation, resources; RM: project administration, funding acquisition.

Ethical policy and Institutional Review board statement

Not applicable.

PATIENT DECLARATION OF CONSENT

Not applicable.

DATA AVAILABILITY STATEMENT

The data are contained in the article.

ACKNOWLEDGEMENT

Not applicable.

REFERENCES

  • 1.Chandran DT, Jagger DC, Jagger RG, Barbour ME. Two- and three-dimensional accuracy of dental impression materials: Effects of storage time and moisture contamination. BioMed Mater Eng. 2010;20:243–9. doi: 10.3233/BME-2010-0638. [DOI] [PubMed] [Google Scholar]
  • 2.Balkenhol M, Haunschild S, Erbe C, Wöstmann B. Influence of prolonged setting time on permanent deformation of elastomeric impression materials. J Prosthet Dent. 2010;103:288–94. doi: 10.1016/S0022-3913(10)60060-1. [DOI] [PubMed] [Google Scholar]
  • 3.Markovi D, Puškar T, Hadžistevi M, Potran M, Blaži L, Hodoli J. The dimensional stability of elastomeric dental impression materials. Contemp Mater. 2012;1:105–10. [Google Scholar]
  • 4.Sinobad T, Obradovic-Djuricic K, Nikolic Z, Dodic S, Lazic V, Sinobad V, et al. The effect of disinfectants on dimensional stability of addition and condensation silicone impressions. Vojnosanit Pregl. 2014;71:251–8. doi: 10.2298/vsp120709037s. [DOI] [PubMed] [Google Scholar]
  • 5.Chee WW, Donovan TE. Polyvinyl siloxane impression materials: A review of properties and techniques. J Prosthet Dent. 1992;68:728–32. doi: 10.1016/0022-3913(92)90192-d. [DOI] [PubMed] [Google Scholar]
  • 6.Chai J, Takahashi Y, Lautenschlager EP. Clinically relevant mechanical properties of elastomeric impression materials. Int J Prosthodont. 1998;11:219–23. [PubMed] [Google Scholar]
  • 7.Huettig F, Klink A, Kohler A, Mutschler M, Rupp F. Flowability, tear strength, and hydrophilicity of current elastomers for dental impressions. Materials (Basel, Switzerland) 2021;14:2994. doi: 10.3390/ma14112994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Cervino G, Fiorillo L, Arzukanyan AV, Spagnuolo G, Cicciu M. Dental restorative digital workflow: digital smile design from aesthetic to function. Dent J (Basel) 2019;7:30. doi: 10.3390/dj7020030. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Ding XZ, Luu C, Huynh L, Wahjudi P, Qian XJ. Hydrophilicity of a new VPS impression material—Take 1 hydro. J Dent Res. 2020;99:2934. [Google Scholar]
  • 10.Klee J, et al. Dental impression material, US 2021/0186825 A1. 2021.
  • 11.Klee J, et al. Dental impression material, US 2021/0106503 A1. 2021.
  • 12.Angeletakis C. Light cured addition silicone impression material with improved storage stability, US 11,154,463 B2. 2021.
  • 13.Jin XM, et al. Macromonomer based light-curable dental impression material, US 11,446,215 B2. 2022.
  • 14.Saini RS, Alshadidi AAF, Hassan SAB, Aldosari LIN, Mosaddad SA, Heboyan A. Properties of a novel composite elastomeric polymer vinyl polyether siloxane in comparison to its parent materials: A systemic review and meta‑analysis. BMC Oral Health. 2024;24:54. doi: 10.1186/s12903-023-03830-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.iData research. U.S. Market Report Suite for Dental Materials. 2017. pp. 113–7. Available from: www.idataresearch.com.
  • 16.Gupta M, George VT, Balakrishnan D. A comparative evaluation of tear strength and tensile strength of autoclavable and non-autoclavable vinylpolysiloxane impression material. An in vitro study. J Int Oral Health. 2020;12:153–7. [Google Scholar]
  • 17.Craig RG, Powers JM, Wataha JC. Dental Materials: Properties and Manipulation. 8th ed. St. Louis, USA: Elsevier; 2003. p. p. 175. [Google Scholar]
  • 18.Haider YM, Mokhtar N, Najim ZT. Effect of different viscosity and tear strength of polyvinyl siloxane impression material on the accuracy of dental implant impressions. Int J Med Res Health Sci. 2018;7:101–9. [Google Scholar]
  • 19.Shen C. Impression materials. In: Anusavice KJ, editor. Philips’ Science of Dental Materials. 11th ed. St. Louis, USA: Elsevier; 2003. pp. pp. 224–31. editor. [Google Scholar]
  • 20.Lu H, Nguyen B, Powers JM. Mechanical properties of 3 hydrophilic addition silicone and polyether elastomeric impression materials. J Prosthet Dent. 2004;92:151–4. doi: 10.1016/j.prosdent.2004.05.016. [DOI] [PubMed] [Google Scholar]
  • 21.Pandey P, Mantri S, Bhasin A, Deogade SC. Mechanical properties of a new vinyl polyether silicone in comparison to vinyl polysiloxane and polyether elastomeric impression materials. Contemp Clin Dent. 2019;10:203–7. doi: 10.4103/ccd.ccd_324_18. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 22.Singer L, Bourauel C, Habib SI, Shalaby HEA, Saniour SH. Tear strength and elastic recovery of new generation hybrid elastomeric impression material: A comparative study. BMC Res Notes. 2022;15:224. doi: 10.1186/s13104-022-06110-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Evans JD. Straightforward Statistics for the Behavioral Sciences. Thomson Brooks/Cole Publishing Co.; Monterey, CA, USA: 1996. [Google Scholar]
  • 24.Moore DS, Notz WI, Flinger MA. The Basic Practice of Statistics. 6th ed. New York, USA: W. H. Freeman and Company; 2013. [Google Scholar]
  • 25.Lawson NC, Burgess JO, Litaker MS. Tensile elastic recovery of elastomeric impression materials. J Prosthet Dent. 2008;100:29–33. doi: 10.1016/S0022-3913(08)60131-6. [DOI] [PubMed] [Google Scholar]
  • 26.Collard EW, Caputo AA, Standlee JP, Trabert KC. Dynamic stresses encountered in impression removal. J Prosthet Dent. 1973;29:498–506. doi: 10.1016/0022-3913(73)90027-9. [DOI] [PubMed] [Google Scholar]
  • 27.Sotiriou M, Hobkirk JA. An in vivo investigation of seating and removal forces associated with recording impressions in dentate patients. J Prosthet Dent. 1995;74:455–62. doi: 10.1016/s0022-3913(05)80345-2. [DOI] [PubMed] [Google Scholar]
  • 28.Ud Din S, Parker S, Braden M, Patel M. The effects of cross-linking agent and surfactant on the tear strength of novel vinyl polysiloxane impression materials. Dent Mater. 2018;34:e334–43. doi: 10.1016/j.dental.2018.09.010. [DOI] [PubMed] [Google Scholar]
  • 29.Ud Din S, Noor N, Humayoun S, Khalid S, Parker S, Patel M. Tensile strength of novel experimental hydrophilic vinyl polysiloxane impression materials compared to control and commercial VPS impression materials. J Islamabad Med Dent Coll. 2018;7:67–72. [Google Scholar]
  • 30.Mandikos MN. Polyvinyl siloxane impression materials: an update on clinical use. Aust Dent J. 1998;43:428–34. doi: 10.1111/j.1834-7819.1998.tb00204.x. [DOI] [PubMed] [Google Scholar]
  • 31.Agrawal P, Dave M, Dhariwal P, Jindal A, Khan FA, Dondani J. Influence of extended setting time on permanent deformation of elastomeric impression materials: an in vitro study. Eur J Molec Clin Med. 2020;7:8557–63. [Google Scholar]
  • 32.Gelest, Inc. Reactive silicones, Ver. 6. https://www.gelest.com/wp-content/uploads/Reactive-SIlicones-No-Price-2016.pdf https://www.gelest.com/wp-content/uploads/Reactive-SIlicones-No-Price-2016.pdf
  • 33.Evonik Corporation. Medical and dental application. https://docplayer.net/101246699-Medical-and-dental-applications.html https://docplayer.net/101246699-Medical-and-dental-applications.html
  • 34.Wu J, Chen L, Li HH, Su BL, Wang YS. Effect of temperature on tensile fatigue life of natural rubber. IOP Conf Ser: Mater Sci Eng. 2018;389:012024–6. [Google Scholar]
  • 35.Ling L, Ma YM, Malyala R. A novel CAD/CAM resin composite block with high mechanical properties. Dent Mater. 2021;37:1150–5. doi: 10.1016/j.dental.2021.03.006. [DOI] [PubMed] [Google Scholar]
  • 36.Jun S, Kim D, Goo H, Lee H. Investigation of the correlation between the different mechanical properties of resin composites. Dent Mater J. 2013;32:48–57. doi: 10.4012/dmj.2012-178. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The data are contained in the article.

Articles from Journal of International Society of Preventive & Community Dentistry are provided here courtesy of Wolters Kluwer -- Medknow Publications

RESOURCES