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A Confocal Microscopic Evaluation of the Dehydration Effect on Conventional, Resin Reinforced Powder/Liquid and Paste to Paste Glass Ionomer Luting Cements.

George L, Kandaswamy D - J Int Oral Health (2015)

Bottom Line: The specimens were allowed to dehydrate under the microscope for different time intervals.Resin modified powder/liquid system did not show cohesive failure.Among the luting cements, resin-modified glass ionomer powder/liquid system showed the best results when subjected to dehydration.

View Article: PubMed Central - PubMed

Affiliation: Professor, Department of Conservative Dentistry and Endodontics, Annoor Dental College, Muvatupuzha, Ernakulam, Kerala, India.

ABSTRACT

Background: The purpose of this study was to evaluate the effect of dehydration of resin-modified glass ionomer powder/liquid system, resin-modified glass ionomer paste/paste luting cements in three different quantities and to compare them with a conventional glass ionomer luting cement using confocal laser scanning microscope.

Materials and methods: A conventional glass ionomer (Group I), a resin modified powder/liquid system (Group II), and a resin-modified paste/paste system (Group III) were selected for the study. In Group III, there were three subgroups based on the quantity of material dispensed. 50 premolar teeth were selected and randomly divided among the groups with 10 samples in each. The teeth were ground flat to expose a flat occlusal dentin. A device was made to standardize the thickness of cement placed on the teeth. The teeth were stored in distilled water for 24 h and then longitudinally sectioned to examine the tooth dentin interface under a confocal microscope. The specimens were allowed to dehydrate under the microscope for different time intervals. The width of the crack after dehydration near the dentinal interface was measured at definite intervals in all the groups and analyzed statistically using Student's t-test.

Results: Conventional glass ionomer cement showed the maximum width of the crack followed by resin modified paste/paste system during the dehydration period. Resin modified powder/liquid system did not show cohesive failure.

Conclusions: Conventional glass ionomer luting cement is more susceptible to cohesive failure when subjected to dehydration compared to resin-modified glass ionomer paste/paste luting cement. Among the luting cements, resin-modified glass ionomer powder/liquid system showed the best results when subjected to dehydration.

No MeSH data available.


Related in: MedlinePlus

Group II sample at 60 min (cement/dentin interface under confocal laser scanning microscope).
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Figure 5: Group II sample at 60 min (cement/dentin interface under confocal laser scanning microscope).

Mentions: The Group II specimens (resin reinforced powder/liquid system) did not show any crack formation throughout the dehydration procedure under the microscope (Figure 3). In this hybrid material part of the water content of the glass, polyalkenoate system is replaced by water soluble polymer or polymerizable resin.17 The addition of HEMA into the liquid along with the catalyst permitted initial polymerization of resin to occur along with shower acid-base reaction. This offered protection to the cement against dehydration. The polymerization of HEMA also offered protection to the calcium polyacrylate chains against dissolution in water.18 The addition of resin caused on the overall increase in fracture toughness of the material.


A Confocal Microscopic Evaluation of the Dehydration Effect on Conventional, Resin Reinforced Powder/Liquid and Paste to Paste Glass Ionomer Luting Cements.

George L, Kandaswamy D - J Int Oral Health (2015)

Group II sample at 60 min (cement/dentin interface under confocal laser scanning microscope).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4588785&req=5

Figure 5: Group II sample at 60 min (cement/dentin interface under confocal laser scanning microscope).
Mentions: The Group II specimens (resin reinforced powder/liquid system) did not show any crack formation throughout the dehydration procedure under the microscope (Figure 3). In this hybrid material part of the water content of the glass, polyalkenoate system is replaced by water soluble polymer or polymerizable resin.17 The addition of HEMA into the liquid along with the catalyst permitted initial polymerization of resin to occur along with shower acid-base reaction. This offered protection to the cement against dehydration. The polymerization of HEMA also offered protection to the calcium polyacrylate chains against dissolution in water.18 The addition of resin caused on the overall increase in fracture toughness of the material.

Bottom Line: The specimens were allowed to dehydrate under the microscope for different time intervals.Resin modified powder/liquid system did not show cohesive failure.Among the luting cements, resin-modified glass ionomer powder/liquid system showed the best results when subjected to dehydration.

View Article: PubMed Central - PubMed

Affiliation: Professor, Department of Conservative Dentistry and Endodontics, Annoor Dental College, Muvatupuzha, Ernakulam, Kerala, India.

ABSTRACT

Background: The purpose of this study was to evaluate the effect of dehydration of resin-modified glass ionomer powder/liquid system, resin-modified glass ionomer paste/paste luting cements in three different quantities and to compare them with a conventional glass ionomer luting cement using confocal laser scanning microscope.

Materials and methods: A conventional glass ionomer (Group I), a resin modified powder/liquid system (Group II), and a resin-modified paste/paste system (Group III) were selected for the study. In Group III, there were three subgroups based on the quantity of material dispensed. 50 premolar teeth were selected and randomly divided among the groups with 10 samples in each. The teeth were ground flat to expose a flat occlusal dentin. A device was made to standardize the thickness of cement placed on the teeth. The teeth were stored in distilled water for 24 h and then longitudinally sectioned to examine the tooth dentin interface under a confocal microscope. The specimens were allowed to dehydrate under the microscope for different time intervals. The width of the crack after dehydration near the dentinal interface was measured at definite intervals in all the groups and analyzed statistically using Student's t-test.

Results: Conventional glass ionomer cement showed the maximum width of the crack followed by resin modified paste/paste system during the dehydration period. Resin modified powder/liquid system did not show cohesive failure.

Conclusions: Conventional glass ionomer luting cement is more susceptible to cohesive failure when subjected to dehydration compared to resin-modified glass ionomer paste/paste luting cement. Among the luting cements, resin-modified glass ionomer powder/liquid system showed the best results when subjected to dehydration.

No MeSH data available.


Related in: MedlinePlus