Flexibility of experimental alumina/feldspar and SR ADORO dental composites.
BACKGROUND
Flexure of a dental composite can be detrimental to the success of a restoration. Flexibility considerations are thus important when comparing dental materials to optimize the success of resin restorations.


OBJECTIVE
Flexibility of 5.6 x 18.0 x 2.0 mm3 experimental alumina/feldspar and SR ADORO dental composites specimens were compared. It was hypothesized that alumina/feldspar composites would be less flexible under a load than SR ADORO composites and that the flexibility would decrease significantly as the feldspar content was increased.


METHODS
Alumina was chemically sintered or bonded with 40%, 50% and 60% feldspar mass, silanized and infiltrated with urethane dimethacrylate (UDMA) to prepare the alumina/feldspar dental restorative composite specimens. Three point bending tests were performed in the Instron 44 machine for flexural comparison to SR ADORO.


CONCLUSIONS
The alumina/feldspar specimens showed lower flexibility (mm displacement) than SR ADORO (p < 0.05). Accurate flexibility comparisons were performed with 5.6 x 18.0 x 2.0 mm3 specimens. Flexibility comparisons performed with 5.6 x 18.0 x 2.0 mm3 specimens indicated that experimental alumina/feldspar dental composites may provide added marginal seal benefit. However confirmation via in vivo function of alumina/feldspar dental composites is recommended.
Department of Dental Services, Faculty of Health Science, Durban University of Technology, Durban, South Africa. andrelr@dut.ac.za
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AR
Le Roux
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Lachman
D000537:Aluminum Oxide / Q000737:chemistry*; D000538:Aluminum Silicates / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010316:Particle Size; D018583:Pliability; D011140:Polyurethanes / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013997:Time Factors
D000538:Aluminum Silicates; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D008689:Methacrylates; C076808:Monobond S; D011140:Polyurethanes; D017680:Potassium Compounds; D012821:Silanes; C016447:feldspar; C029824:urethane dimethacrylate luting resin; D000537:Aluminum Oxide