What are OCL (Occlusal) splints made of?

Materials Used for Occlusal (OCL) Splints

Occlusal splints are primarily made from hard acrylic resin, soft rubber/elastic materials, or thermo-flexible resin, with hard acrylic splints being the most common and generally most effective for long-term management of temporomandibular disorders (TMDs). 1

Types of Materials Used for OCL Splints

Hard Materials

• Heat-cured acrylic resin: Traditional material offering durability and stability 1, 2
• Clear transparent acrylic resin: Commonly used for hard flat occlusal splints 3
• Light-cured composite: Newer material with minimal distortion that can be constructed in-office in under 30 minutes 4
• Milled materials: CAD/CAM fabricated splints using materials like ProArt CAD splint (Ivoclar) 5

Soft Materials

• Elastic rubber sheets: Typically 2mm thick, vacuum-formed 3
• Thermo-flexible resin: Newer material for 3D printing of splints (e.g., V-print splint comfort) 5

Efficacy of Different Materials

Hard vs. Soft Splints

• Hard full coverage stabilization splints show efficacy for TMD management 1
• Soft occlusal splints demonstrated superior results in some studies after 4 months of use for myofacial pain dysfunction and internal derangement of TMJ 3
• Hard splints that don't account for occlusion may cause adverse events like tooth movement and malocclusion 1

Modern Manufacturing Methods

• 3D-printed splints using thermo-flexible resin perform similarly to milled splints in terms of:
  • Patient satisfaction (8.0 vs 8.1 on a 10-point scale)
  • Complication rates
  • Wear behavior 5

Clinical Considerations for Material Selection

For TMD Management

• Hard full coverage stabilization splints are recommended by dental professionals 1
• Soft splints may be beneficial for short-term use (up to 4 months) 3
• Material selection should consider the specific TMD diagnosis and symptoms 1

For Bruxism

• Hard acrylic splints are traditionally preferred for nocturnal bruxism 1
• Thermo-flexible materials show promise for bruxism management 5

For Patients with Limited Mouth Opening

• Combined direct-indirect techniques using heat-cured acrylic resin can be employed when taking impressions is difficult 2
• Extra-hard baseplate wax can be used as a template for fabrication 2

Pitfalls and Caveats

• Splints that don't account for proper occlusion may cause adverse events including tooth movement and malocclusion 1
• Material selection should consider durability requirements based on the severity of bruxism or clenching 1, 4
• Small crack formations can occur in both printed (6/23) and milled (4/24) splints within 3 months of use 5
• Occlusal splints should be considered before more invasive procedures like TMJ surgery, occlusal equilibration, or orthodontics 4

In conclusion, while multiple materials are available for OCL splint fabrication, the selection should be based on the specific clinical situation, with hard acrylic materials generally preferred for long-term use and newer thermo-flexible materials showing promise for 3D-printed alternatives.