An ex vivo evaluation of resin-modified glass polyalkenoates and polyacid-modified composite resins as orthodontic band cements.
OBJECTIVE
The objective of this ex vivo study was to assess the use of resin-modified glass polyalkenoates and polyacid-modified composite resins, as orthodontic band cements.


METHODS
Plain stainless steel bands were cemented to 350 human extracted third molar teeth using 1 of 7 different cements. Following complete cement cure, half of each sample group was exposed to mechanical stress in a ball mill. Stressed and unstressed samples were tested in tension and the stress at which initial cement failure recorded. The mode of failure was recorded using an adhesive remnant evaluation.


RESULTS
The mean band retention stresses offered by the cements studied ranged from 0.96 to 1.56 MPa. Fuji Ortho provided the highest mean band retention stress in "stressed" (1.56 MPa) and "unstressed" (1.45 MPa) states. Exposure to mechanical stress did not appear to significantly influence band retention or mode of cement failure for most cements. Fuji Ortho cement recorded the highest Weibull modulus for all cements tested. Virtually all samples failed at either the cement/enamel or cement band interface.


CONCLUSIONS
Significant differences in band displacement stress values and mode of failure were demonstrated between the cements studied. However, generic comparisons were difficult to make.
Knox
J
J
Department of Dental Health and Development, University Of Wales College Of Medicine, Dental School, Heath Park, Cardiff CF4 4XY, Wales, UK. Knoxj@cardiff.ac.uk
Chye
K Y
KY
Durning
P
P
D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000538:Aluminum Silicates / Q000737:chemistry; D020770:Compomers / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing; D016910:Orthodontic Brackets; D011076:Polycarboxylate Cement / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D015034:Zinc Oxide / Q000737:chemistry; D015036:Zinc Phosphate Cement / Q000737:chemistry
D000180:Acrylic Resins; D000538:Aluminum Silicates; C104870:Band-Lok; D020770:Compomers; D003738:Dental Cements; C477387:EP glass polyphosphonate cement; C112133:Fuji Ortho; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D019279:Resin Cements; D013193:Stainless Steel; D008277:Magnesium Oxide; D015036:Zinc Phosphate Cement; C040235:Ketac-cem; D015034:Zinc Oxide