Orthodontic brackets made from polymeric materials that impart desired strength properties

An orthodontic bracket comprising:

• a bracket base;
• at least one arch wire slot within the bracket base adapted to receive an arch wire therein;
• and
• a ligation cover integrally attached to the bracket base by a flexible integral hinge element so that the ligation cover can be selectively rotated relative to the bracket base between an open, non-ligating position relative to the arch wire slot and a closed, ligating position relative to the arch wire slot,
• wherein the bracket base, ligation cover, and hinge element are integrally formed together as a single piece and compromise at least one type of crystalline polymer and at least one type of amorphous polymer,
• wherein the integral hinge element has increased elasticity, flexibility and toughness as compared to a hinge element consisting solely of a crystalline polymer.

An orthodontic bracket comprising:

• a bracket base;
• at least one arch wire slot within the bracket base adapted to receive an arch wire therein;
• and
• a ligation cover hingedly attached to the bracket base by a flexible elongate film hinge so that the ligation cover is selectively rotatable relative to the bracket base about the elongate film hinge between an open, non-ligating position relative to the arch wire slot in which the arch wire slot is completely unoccluded by the ligation cover and a closed, ligating position relative to the arch wire slot,
• wherein the bracket base, ligation cover, and elongate film hinge are integrally formed together as a single piece and comprise at least one type of crystalline polymer,
• wherein the orthodontic bracket has an increased resistance to deformation when an arch wire is positioned within the arch wire slot over time compared to an orthodontic bracket consisting solely of an amorphous polymer.

An orthodontic bracket comprising:

• a bracket base;
• at least one arch wire slot within the bracket base adapted to receive an arch wire therein;
• and
• a ligation cover that can be selectively moved relative to the bracket base between an open, non-ligating position relative to the arch wire slot and a closed, ligating position relative to the arch wire slot,
• wherein the bracket base and ligation cover are integrally connected together by a flexible integral hinge element,
• wherein the bracket base, ligation cover, and hinge element comprise at least one type of crystalline polymer,
• wherein the bracket base, ligation cover, and hinge element are formed together as a single integral piece, and
• wherein the integral hinge element has increased tensile strength compared to a hinge element consisting solely of an amorphous polymer.