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Covering of fiber-reinforced composite bars by adhesive materials, is it necessary to improve the bond strength of lingual retainers?

Heravi F, Kerayechian N, Moazzami SM, Shafaee H, Heravi P - J Orthod Sci (2015 Oct-Dec)

Bottom Line: Thermal cycling did not significantly change the SBS values (P = 0.537).Overall, eight groups were statistically different (ANOVA test, F = 3.32, P = 0.034), but no significant differences in bond failure locations were found between the groups (Fisher's exact tests, P = 0.92).The present findings showed no significant differences between SBS of FRC bars with and without covering by RMGIC.

View Article: PubMed Central - PubMed

Affiliation: Dental Research Center, Department of Orthodontics, Dental Research Center of Mashhad University of Medical Sciences, School of Dentistry, Mashhad, Iran.

ABSTRACT

Objectives: The objectives were to evaluate the shear bond strength (SBS) of fiber-reinforced composite (FRC) retainers when bonding them to teeth with and without covering the FRC bars using two different adhesive systems.

Materials and methods: Hundred and twenty extracted human maxillary premolars were randomly divided into eight groups (n = 15). FRC bars (4 mm length, Everstick Ortho(®), Stick Tech, Oy, Turku, Finland) were bonded to the proximal (distal) surfaces of the teeth using two different adhesives (Tetric Flow [TF, Ivoclar Vivadent, Switzerland] and resin-modified glass ionomer cement [RMGIC, ODP, Vista, CA, USA]) with and without covering with the same adhesive. Specimens were exposed to thermocycling (625 cycles per day [5-55°C, intervals: 30 s] for 8 days). The SBS test was then performed using the universal testing machine (Zwick, GMBH, Ulm, Germany). After debonding, the remaining adhesive on the teeth was recorded by the adhesive remnant index (0-3).

Results: The lowest mean SBS (standard deviation) was found in the TF group without covering with adhesive (12.6 [2.11] MPa), and the highest bond strength was in the TF group with covering with adhesive (16.01 [1.09] MPa). Overall, the uncovered RMGIC (15.65 [3.57] MPa) provided a higher SBS compared to the uncovered TF. Covering of FRC with TF led to a significant increase in SBS (P = 0.001), but this was not true for RMGIC (P = 0.807). Thermal cycling did not significantly change the SBS values (P = 0.537). Overall, eight groups were statistically different (ANOVA test, F = 3.32, P = 0.034), but no significant differences in bond failure locations were found between the groups (Fisher's exact tests, P = 0.92).

Conclusions: The present findings showed no significant differences between SBS of FRC bars with and without covering by RMGIC. However, when using TF, there was a significant difference in SBS measurements between covering and noncovering groups. Therefore, the use of RMGIC without covering FRC bars can be suggested, which can be validated with in vivo studies.

No MeSH data available.


Related in: MedlinePlus

Surveyor device
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Figure 1: Surveyor device

Mentions: Thereafter, the samples of the first four groups were mounted in acrylic using a surveyor device (JM Ney Company, Hartford, Connecticut, USA) [Figure 1]. Using this tool, the distal surface of the tooth (on which the FRC were bonded) was perpendicular to the horizon to secure the Zwick device blade occluso-gingivally on the bonded FRC. Subsequently, the mounted specimens were placed in distilled water for 24 h at room temperature. At this point, the SBS measurement process was performed using the Zwick device, and FRCs were debonded by applying the shear force of the blade at the speed of 1 mm/min. Then, the maximum required force to debond FRCs was registered based on Newton and transferred to Megapascal by dividing to FRC bonded cross section (4 mm × 1.5 mm = 6 mm2).


Covering of fiber-reinforced composite bars by adhesive materials, is it necessary to improve the bond strength of lingual retainers?

Heravi F, Kerayechian N, Moazzami SM, Shafaee H, Heravi P - J Orthod Sci (2015 Oct-Dec)

Surveyor device
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4759972&req=5

Figure 1: Surveyor device
Mentions: Thereafter, the samples of the first four groups were mounted in acrylic using a surveyor device (JM Ney Company, Hartford, Connecticut, USA) [Figure 1]. Using this tool, the distal surface of the tooth (on which the FRC were bonded) was perpendicular to the horizon to secure the Zwick device blade occluso-gingivally on the bonded FRC. Subsequently, the mounted specimens were placed in distilled water for 24 h at room temperature. At this point, the SBS measurement process was performed using the Zwick device, and FRCs were debonded by applying the shear force of the blade at the speed of 1 mm/min. Then, the maximum required force to debond FRCs was registered based on Newton and transferred to Megapascal by dividing to FRC bonded cross section (4 mm × 1.5 mm = 6 mm2).

Bottom Line: Thermal cycling did not significantly change the SBS values (P = 0.537).Overall, eight groups were statistically different (ANOVA test, F = 3.32, P = 0.034), but no significant differences in bond failure locations were found between the groups (Fisher's exact tests, P = 0.92).The present findings showed no significant differences between SBS of FRC bars with and without covering by RMGIC.

View Article: PubMed Central - PubMed

Affiliation: Dental Research Center, Department of Orthodontics, Dental Research Center of Mashhad University of Medical Sciences, School of Dentistry, Mashhad, Iran.

ABSTRACT

Objectives: The objectives were to evaluate the shear bond strength (SBS) of fiber-reinforced composite (FRC) retainers when bonding them to teeth with and without covering the FRC bars using two different adhesive systems.

Materials and methods: Hundred and twenty extracted human maxillary premolars were randomly divided into eight groups (n = 15). FRC bars (4 mm length, Everstick Ortho(®), Stick Tech, Oy, Turku, Finland) were bonded to the proximal (distal) surfaces of the teeth using two different adhesives (Tetric Flow [TF, Ivoclar Vivadent, Switzerland] and resin-modified glass ionomer cement [RMGIC, ODP, Vista, CA, USA]) with and without covering with the same adhesive. Specimens were exposed to thermocycling (625 cycles per day [5-55°C, intervals: 30 s] for 8 days). The SBS test was then performed using the universal testing machine (Zwick, GMBH, Ulm, Germany). After debonding, the remaining adhesive on the teeth was recorded by the adhesive remnant index (0-3).

Results: The lowest mean SBS (standard deviation) was found in the TF group without covering with adhesive (12.6 [2.11] MPa), and the highest bond strength was in the TF group with covering with adhesive (16.01 [1.09] MPa). Overall, the uncovered RMGIC (15.65 [3.57] MPa) provided a higher SBS compared to the uncovered TF. Covering of FRC with TF led to a significant increase in SBS (P = 0.001), but this was not true for RMGIC (P = 0.807). Thermal cycling did not significantly change the SBS values (P = 0.537). Overall, eight groups were statistically different (ANOVA test, F = 3.32, P = 0.034), but no significant differences in bond failure locations were found between the groups (Fisher's exact tests, P = 0.92).

Conclusions: The present findings showed no significant differences between SBS of FRC bars with and without covering by RMGIC. However, when using TF, there was a significant difference in SBS measurements between covering and noncovering groups. Therefore, the use of RMGIC without covering FRC bars can be suggested, which can be validated with in vivo studies.

No MeSH data available.


Related in: MedlinePlus