- Email: [email protected]
Physicochemical properties of methacrylate resin-based root canal sealers
e14
d e n t a l m a t e r i a l s 3 3 S ( 2 0 1 7 ) e1–e92
23
24
Physicochemical properties of methacrylate resin-based root canal sealers
Resin materials containing calcium phosphate nanoparticles functionalized with EGDMA derivatives
C.C. Borges ∗ , Y.T.C. Silva-Sousa, F.C. Lopes, A.C. Silva-Sousa, R.G. Silva, I.M.V. Soares, M.D. Sousa-Neto
L.C. Natale, M.C. Rodrigues, Y. Alania, R.R. Braga ∗
School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
University of São Paulo, Department of Biomaterials and Oral Biology, São Paulo, Brazil
Purpose/aim: The aim of this study was to evaluate the following physicochemical properties of the methacrylate resin-based root canal sealers Hybrid Root SEAL (Sun Medical) and Real Seal XT (SybronEndo) compared to epoxy resin-based sealer AH Plus, according to the ANSI/ADA standards: setting time (ST), dimensional change (DC) and solubility (SB). Materials and methods: For analysis of ST, the sealers were placed inside cylindrical stainless steel molds and tested with a Gilmore needle (100 g). For DC, the sealers were placed inside cylindrical molds, measured for length, immersed in distilled water for 30 days, dried and measured again to determine the percentage of the dimensional alterations. For SB, circular molds were filled with the sealers, weighed, immersed in water, reweighed after 7 days, and the liquids were analyzed by atomic absorption spectrometry. Data were analyzed statistically by ANOVA and Tukey’s test (˛ = 5%). Results: The ST means for Hybrid Root SEAL, Real Seal XT, and AH Plus, were 67.00 ± 6.96, 39.00 ± 4.18, and 530.20 ± 44.98, respectively. For DC (Hybrid Root SEAL 4.51 ± 1.03; Real Seal XT 3.32 ± 0.24; and AH Plus 1.31 ± 0.20) and SB (Hybrid Root SEAL −1.24 ± 0.38; Real Seal XT −0.90 ± 0.14; and AH Plus 0.39 ± 0.083), AH Plus presented better results. There was statistically significant difference between the sealers for the physicochemical properties ST, DC and SB, with lower DC and higher ST and SB values for AH Plus (p < 0.05) (Table 1). The results of the atomic absorption spectrometry showed greater release of Na+ ions from Hybrid Root SEAL compared to Real Seal XT and AH Plus sealers (p < 0.05). For Ni+ ions no significant release was found for the sealers tested (<0.5 ppm), as well as the Ca2+ release from Hybrid Root SEAL sealer.
Purpose/aim: The incorporation of calcium orthophosphate nanoparticles (NPs) to restorative composites has been investigated over the years as a possible approach to protect the enamel against the development of new caries lesions at the tooth–restoration interface. However, the lack of chemical interaction between the nanoparticles and the resin matrix significantly reduces the mechanical properties of the resulting material. Recently, dicalcium phosphate dihydrate (DCPD) nanoparticles functionalized with triethylene glycol dimethacrylate (TEGDMA) were synthesized. Copolymerization of the monomers grafted on the NP surface with those from the resin matrix allowed for a 32% increase in material’s fracture strength. The aim of the present study was to investigate the effect of DCPD NPs functionalized with different the ethylene glycol dimethacrylate (EGDMA) derivatives on the mechanical properties of a dimethacrylate-based resin. Materials and methods: DCPD NPs functionalized with DEGDMA, TEGDMA or TETDMA were synthesized by a sol–gel method using calcium nitrate and ammonium phosphate solutions as precursors. Monomers were added to the ammonium phosphate solution in 1:1 (DEGDMA) or 2:1 (DEGDMA, TEGDMA and TETDMA) molar ratios in relation to ammonium phosphate. NPs (30 vol%) were incorporated to a photocurable BisGMA:TEGDMA mixture (1:1 in mol). The unfilled resin and a material containing non-functionalized (NF) DCPD were tested as controls. Disc-shaped specimens (12 × 1.2 mm, n = 10) were aged for 24 h in water prior to testing on a “disc on three spheres” device. Biaxial flexural strength (BFS) and flexural modulus (FM) data were analyzed using Kruskal–Wallis test, with multiple comparisons performed using Dunn’s test (alpha: 5%). Results: Results are shown in Fig. 1. Averages followed by the same letter are not statistically different (p > 0.05). Fracture strength of the resin-based material containing 2:1 DEGDMAfunctionalized DCPD increased 44% in comparison to the use of non-functionalized NPs (73.3 and 52.8 MPa, respectively).
Table 1 – Physical properties of the sealers (mean ± standard deviation).
Setting time (min) Dimensional change (%) Solubility (%)
Hybrid Root SEAL
Real Seal XT
AH Plus
67.00 ± 6.96b
39.00 ± 4.18b
530.20 ± 44.98a
4.51 ± 1.03b
3.32 ± 0.24b
1.31 ± 0.20a
−1.24 ± 0.38b
−0.90 ± 0.14b
0.39 ± 0.083a
Lowercase letters indicate statistically significant difference in columns (p < 0.05).
Conclusions: Only AH Plus fulfilled all ANSI/ADA recommendations relative to the physicochemical properties evaluated in this study. http://dx.doi.org/10.1016/j.dental.2017.08.024
Fig. 1
d e n t a l m a t e r i a l s 3 3 S ( 2 0 1 7 ) e1–e92
23
24
Physicochemical properties of methacrylate resin-based root canal sealers
Resin materials containing calcium phosphate nanoparticles functionalized with EGDMA derivatives
C.C. Borges ∗ , Y.T.C. Silva-Sousa, F.C. Lopes, A.C. Silva-Sousa, R.G. Silva, I.M.V. Soares, M.D. Sousa-Neto
L.C. Natale, M.C. Rodrigues, Y. Alania, R.R. Braga ∗
School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
University of São Paulo, Department of Biomaterials and Oral Biology, São Paulo, Brazil
Purpose/aim: The aim of this study was to evaluate the following physicochemical properties of the methacrylate resin-based root canal sealers Hybrid Root SEAL (Sun Medical) and Real Seal XT (SybronEndo) compared to epoxy resin-based sealer AH Plus, according to the ANSI/ADA standards: setting time (ST), dimensional change (DC) and solubility (SB). Materials and methods: For analysis of ST, the sealers were placed inside cylindrical stainless steel molds and tested with a Gilmore needle (100 g). For DC, the sealers were placed inside cylindrical molds, measured for length, immersed in distilled water for 30 days, dried and measured again to determine the percentage of the dimensional alterations. For SB, circular molds were filled with the sealers, weighed, immersed in water, reweighed after 7 days, and the liquids were analyzed by atomic absorption spectrometry. Data were analyzed statistically by ANOVA and Tukey’s test (˛ = 5%). Results: The ST means for Hybrid Root SEAL, Real Seal XT, and AH Plus, were 67.00 ± 6.96, 39.00 ± 4.18, and 530.20 ± 44.98, respectively. For DC (Hybrid Root SEAL 4.51 ± 1.03; Real Seal XT 3.32 ± 0.24; and AH Plus 1.31 ± 0.20) and SB (Hybrid Root SEAL −1.24 ± 0.38; Real Seal XT −0.90 ± 0.14; and AH Plus 0.39 ± 0.083), AH Plus presented better results. There was statistically significant difference between the sealers for the physicochemical properties ST, DC and SB, with lower DC and higher ST and SB values for AH Plus (p < 0.05) (Table 1). The results of the atomic absorption spectrometry showed greater release of Na+ ions from Hybrid Root SEAL compared to Real Seal XT and AH Plus sealers (p < 0.05). For Ni+ ions no significant release was found for the sealers tested (<0.5 ppm), as well as the Ca2+ release from Hybrid Root SEAL sealer.
Purpose/aim: The incorporation of calcium orthophosphate nanoparticles (NPs) to restorative composites has been investigated over the years as a possible approach to protect the enamel against the development of new caries lesions at the tooth–restoration interface. However, the lack of chemical interaction between the nanoparticles and the resin matrix significantly reduces the mechanical properties of the resulting material. Recently, dicalcium phosphate dihydrate (DCPD) nanoparticles functionalized with triethylene glycol dimethacrylate (TEGDMA) were synthesized. Copolymerization of the monomers grafted on the NP surface with those from the resin matrix allowed for a 32% increase in material’s fracture strength. The aim of the present study was to investigate the effect of DCPD NPs functionalized with different the ethylene glycol dimethacrylate (EGDMA) derivatives on the mechanical properties of a dimethacrylate-based resin. Materials and methods: DCPD NPs functionalized with DEGDMA, TEGDMA or TETDMA were synthesized by a sol–gel method using calcium nitrate and ammonium phosphate solutions as precursors. Monomers were added to the ammonium phosphate solution in 1:1 (DEGDMA) or 2:1 (DEGDMA, TEGDMA and TETDMA) molar ratios in relation to ammonium phosphate. NPs (30 vol%) were incorporated to a photocurable BisGMA:TEGDMA mixture (1:1 in mol). The unfilled resin and a material containing non-functionalized (NF) DCPD were tested as controls. Disc-shaped specimens (12 × 1.2 mm, n = 10) were aged for 24 h in water prior to testing on a “disc on three spheres” device. Biaxial flexural strength (BFS) and flexural modulus (FM) data were analyzed using Kruskal–Wallis test, with multiple comparisons performed using Dunn’s test (alpha: 5%). Results: Results are shown in Fig. 1. Averages followed by the same letter are not statistically different (p > 0.05). Fracture strength of the resin-based material containing 2:1 DEGDMAfunctionalized DCPD increased 44% in comparison to the use of non-functionalized NPs (73.3 and 52.8 MPa, respectively).
Table 1 – Physical properties of the sealers (mean ± standard deviation).
Setting time (min) Dimensional change (%) Solubility (%)
Hybrid Root SEAL
Real Seal XT
AH Plus
67.00 ± 6.96b
39.00 ± 4.18b
530.20 ± 44.98a
4.51 ± 1.03b
3.32 ± 0.24b
1.31 ± 0.20a
−1.24 ± 0.38b
−0.90 ± 0.14b
0.39 ± 0.083a
Lowercase letters indicate statistically significant difference in columns (p < 0.05).
Conclusions: Only AH Plus fulfilled all ANSI/ADA recommendations relative to the physicochemical properties evaluated in this study. http://dx.doi.org/10.1016/j.dental.2017.08.024
Fig. 1