DISCUSSION
The term “elastomer” refers to any member of a class of polymeric materials with the ability to regain shape after deformation.27, i The very first common elastomer was natural rubber. There were used by the Maya and Inca civilizations. With the introduction of vulcanization, by Charles Goodyear in the year 1839, the physical properties of rubbers were improved, considerably enhancing its use.27 In the 1920’s, manufacture of synthetic rubber bands were started by the petrochemical industries. Orthodontic practices adopted their use for effective tooth movement from the 1960’s. iii, iv, v
Elastomeric chains are polyurethanes, possessing low molecular weight polymers, usually either polyether or polyester, they form a complex structure by urethane linkage. iv, vi Polyurethane polymers possess rubber like elasticity and have long chains, lightly cross linked structures with a weak molecular attraction consisting of primary and secondary bonds. 27 Prior to stretching, elastomeric chain consists of folded linear molecular chains. Upon extension, these Molecular chains unfold in an ordered linear fashion at the expense of the secondary bonds.11, 12, vii The release of the extension will allow them to return to a passive configuration unless the distraction of the chains has not caused rupture of the primary bonds. If the force applied exceeds the elastic limit of the chains, permanent deformation occurs due to the breakage of primary bonds.viii …show more content…
They have a wide range of clinical applications including tying orthodontic archwires to brackets, as substitutes for steel ligatures, closure of extraction spaces, canine retraction, orthodontic traction of impacted teeth, correction of torsiversion and midline deviation, etc. They are practical, efficient and are available in a variety of colours. With convenient placement, they are also comfortable to the
The term “elastomer” refers to any member of a class of polymeric materials with the ability to regain shape after deformation.27, i The very first common elastomer was natural rubber. There were used by the Maya and Inca civilizations. With the introduction of vulcanization, by Charles Goodyear in the year 1839, the physical properties of rubbers were improved, considerably enhancing its use.27 In the 1920’s, manufacture of synthetic rubber bands were started by the petrochemical industries. Orthodontic practices adopted their use for effective tooth movement from the 1960’s. iii, iv, v
Elastomeric chains are polyurethanes, possessing low molecular weight polymers, usually either polyether or polyester, they form a complex structure by urethane linkage. iv, vi Polyurethane polymers possess rubber like elasticity and have long chains, lightly cross linked structures with a weak molecular attraction consisting of primary and secondary bonds. 27 Prior to stretching, elastomeric chain consists of folded linear molecular chains. Upon extension, these Molecular chains unfold in an ordered linear fashion at the expense of the secondary bonds.11, 12, vii The release of the extension will allow them to return to a passive configuration unless the distraction of the chains has not caused rupture of the primary bonds. If the force applied exceeds the elastic limit of the chains, permanent deformation occurs due to the breakage of primary bonds.viii …show more content…
They have a wide range of clinical applications including tying orthodontic archwires to brackets, as substitutes for steel ligatures, closure of extraction spaces, canine retraction, orthodontic traction of impacted teeth, correction of torsiversion and midline deviation, etc. They are practical, efficient and are available in a variety of colours. With convenient placement, they are also comfortable to the