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Mechanical and thermal properties of polyamide versus reinforced PMMA denture base materials.

Soygun K, Bolayir G, Boztug A - J Adv Prosthodont (2013)

Bottom Line: The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance.IN ALL MECHANICAL TESTS, THE HIGHEST VALUES WERE OBSERVED IN VALPLAST GROUP (TRANSVERSE STRENGTH: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN).Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.

ABSTRACT

Purpose: This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added.

Materials and methods: FIVE GROUPS WERE FORMED: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance.

Results: IN ALL MECHANICAL TESTS, THE HIGHEST VALUES WERE OBSERVED IN VALPLAST GROUP (TRANSVERSE STRENGTH: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples.

Conclusion: Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.

No MeSH data available.


N6 fiber-added specimen (original magnifications ×300).
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Figure 7: N6 fiber-added specimen (original magnifications ×300).

Mentions: Structural images of the specimens were obtained by using a surface scanning electron microscope. The assessments in fiber-added specimens were made in terms of fiber-resin connection and fiber distribution (Fig. 4, 5, 6 and 7). It was evident on the images that both the control group (Fig. 4A) and the Valplast group displayed a smoother and more compact structure than other specimen groups (Fig. 4B). In the KCR4 fiber specimens group, it was observed that the glass fibers formed bunch-shaped structures inside the resin matrix together with adhesion of acrylic resin. Some pores could also be seen that might have resulted from disintegrations from the resin matrix (Fig. 5). In the fiber specimens to which N6.6 and N6 were added, no interfacial adhesion with the resin was observed, and some cavities appeared to have formed on the interface with the resin matrix. This observation could indicate that some flexions might have occurred on these fibers before fracturing (Fig. 6 and 7).


Mechanical and thermal properties of polyamide versus reinforced PMMA denture base materials.

Soygun K, Bolayir G, Boztug A - J Adv Prosthodont (2013)

N6 fiber-added specimen (original magnifications ×300).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3675288&req=5

Figure 7: N6 fiber-added specimen (original magnifications ×300).
Mentions: Structural images of the specimens were obtained by using a surface scanning electron microscope. The assessments in fiber-added specimens were made in terms of fiber-resin connection and fiber distribution (Fig. 4, 5, 6 and 7). It was evident on the images that both the control group (Fig. 4A) and the Valplast group displayed a smoother and more compact structure than other specimen groups (Fig. 4B). In the KCR4 fiber specimens group, it was observed that the glass fibers formed bunch-shaped structures inside the resin matrix together with adhesion of acrylic resin. Some pores could also be seen that might have resulted from disintegrations from the resin matrix (Fig. 5). In the fiber specimens to which N6.6 and N6 were added, no interfacial adhesion with the resin was observed, and some cavities appeared to have formed on the interface with the resin matrix. This observation could indicate that some flexions might have occurred on these fibers before fracturing (Fig. 6 and 7).

Bottom Line: The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance.IN ALL MECHANICAL TESTS, THE HIGHEST VALUES WERE OBSERVED IN VALPLAST GROUP (TRANSVERSE STRENGTH: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN).Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples.

View Article: PubMed Central - PubMed

Affiliation: Department of Prosthodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.

ABSTRACT

Purpose: This in vitro study intended to investigate the mechanical and thermal characteristics of Valplast, and of polymethyl methacrylate denture base resin in which different esthetic fibers (E-glass, nylon 6 or nylon 6.6) were added.

Materials and methods: FIVE GROUPS WERE FORMED: control (PMMA), PMMA-E glass, PMMA-nylon 6, PMMA-nylon 6.6 and Valplast resin. For the transverse strength test the specimens were prepared in accordance with ANSI/ADA specification No.12, and for the impact test ASTM D-256 standard were used. With the intent to evaluate the properties of transverse strength, the three-point bending (n=7) test instrument (Lloyd NK5, Lloyd Instruments Ltd, Fareham Hampshire, UK) was used at 5 mm/min. A Dynatup 9250 HV (Instron, UK) device was employed for the impact strength (n=7). All of the resin samples were tested by using thermo-mechanical analysis (Shimadzu TMA 50, Shimadzu, Japan). The data were analyzed by Kruskal-Wallis and Tukey tests for pairwise comparisons of the groups at the 0.05 level of significance.

Results: IN ALL MECHANICAL TESTS, THE HIGHEST VALUES WERE OBSERVED IN VALPLAST GROUP (TRANSVERSE STRENGTH: 117.22 ± 37.80 MPa, maximum deflection: 27.55 ± 1.48 mm, impact strength: 0.76 ± 0.03 kN). Upon examining the thermo-mechanical analysis data, it was seen that the E value of the control sample was 8.08 MPa, higher than that of the all other samples.

Conclusion: Although Valplast denture material has good mechanical strength, its elastic modulus is not high enough to meet the standard of PMMA materials.

No MeSH data available.