Täyttönauloja

Täyttönauloja (filling pins) are small metal pins used in dentistry to improve retention of restorations. They are inserted into prepared cavities to provide mechanical retention for restorative materials such as amalgam or composite when the remaining tooth structure is insufficient to retain the restoration by bonding alone. The pins may extend into dentin or into deeper root dentin, depending on the location and design, and are typically secured with cement or a bonding agent. After placement, the chosen restorative material is built up around the pins and finished to restore function and appearance.

Historically, täyttönauloja gained prominence in the early to mid-20th century as a common retention method in cavity restorations. With advances in adhesive dentistry and modern bonding systems, their use has declined and they are now reserved for specific cases where conventional bonding provides limited retention or where substantial tooth structure loss would otherwise jeopardize the restoration.

Materials and designs vary. Stainless steel is common, but gold or other alloys have been used in the past. Designs include straight and serrated variants to enhance mechanical interlocking with the surrounding tooth structure. Potential drawbacks include the risk of tooth fracture if pins are placed too close to the pulp or root, possible microleakage around the pin, and increased technique sensitivity. Proper case selection and meticulous technique are essential to minimize complications.

In contemporary practice, many clinicians favor alternative retention methods such as post-and-core systems, fiber posts, or full-coverage crowns. When used, täyttönauloja are integrated with careful restoration planning to maximize longevity and preserve tooth vitality. See also dental pin, tooth restoration, adhesive dentistry.