Coil spring (OA-0306)researched

Quick facts

Field	Value
ID	OA-0306
Type	component
Category	component
See also	Open coil spring Open coil spring; Closed coil spring Closed coil spring

Overview

OA-0306 "Coil spring" is a generic catalog entry covering NiTi and SS coil springs used in fixed orthodontic therapy. Full research is split by spring type: Open coil spring (open coil — pushes teeth apart) and Closed coil spring (closed coil — pulls teeth together).

Common variants & modifications

• Open coil (NiTi): space opening; compressed between brackets;

constant light force

• Closed coil (NiTi): space closure; stretched between hooks;

pulls teeth together

• Open coil (stainless steel): heavier force; used for more

aggressive space opening

• Sectional coil (short): 3–5 mm; one-tooth space opening
• Calibrated force coil: sold with specific load ratings (150 g,

200 g, 300 g) for predictable force management

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Sources

• [Coil Springs in Fixed Appliance Therapy —

JCO](https://www.jco-online.com)

• [Open and Closed Coil Spring Applications —

AJO-DO](https://www.ajodo.org)

• [Spring Systems Overview — Rocky Mountain

Orthodontics](https://www.rmortho.com)

Research log

• 2026-06-09 — cross-referenced to OA-0193 and OA-0194.