Tensile strength of Ni-Cr copings subjected to inner surface sandblasting using different cementing agents: An in vitro study.
OBJECTIVES
To evaluate the effect of thermal cycling and inner surface treatment with aluminum oxide at different granulations on the tensile strength of Ni-Cr copings cemented with different cementing agents.


MATERIALS AND METHODS
Ninety-six metal copings were manufactured and divided into two groups: before and after thermal cycling (n = 48). The copings of both groups were internally treated by sandblasting with aluminum oxide particles of 100 (n = 24) and 320 (n = 24) mesh. The copings were cemented on previously manufactured metal cores using zinc phosphate (n = 8), conventional glass ionomer (CGIC) (n = 8) and resin-modified glass ionomer (RMGIC) (n = 8) cements. The tensile strength before and after thermal cycling was then determined (Newtons).


RESULTS
The tensile strength before and after thermal cycling was significantly higher in copings cemented with RMGIC compared to CGIC (p < 0.05) and was similar to that for zinc phosphate (p > 0.05). Thermal cycling and sandblasting of the inner surface of the metal copings with different granulations did not influence retention (p > 0.05).


CONCLUSIONS
Zinc phosphate cements and RMGIC showed similar retention. Additionally, the retention of the cements was not influenced by either thermal cycling or the particle size of the aluminum oxide.
['Peixoto|Raniel Fernandes|RF|', 'Hermanson|Marília Pedrão|MP|', 'Pupim|Denise|D|', 'Rodrigues|Renata Cristina Silveira|RC|', 'Antunes|Rossana Pereira Almeida|RP|', 'de Mattos|Maria da Gloria Chiarello|Mda G|']
D000537:Aluminum Oxide D002484:Cementation D002858:Chromium Alloys D003442:Crowns D003735:Dental Casting Technique D003738:Dental Cements D045662:Dental Etching D017268:Dental Prosthesis Retention D003799:Dental Stress Analysis D005899:Glass Ionomer Cements D006801:Humans D008422:Materials Testing D008855:Microscopy, Electron, Scanning D010316:Particle Size D019279:Resin Cements D013314:Stress, Mechanical D013499:Surface Properties D013696:Temperature D013718:Tensile Strength D015036:Zinc Phosphate Cement
Tensile strength thermal cycling metal coping dental cements