Retention and Durability of the Anterior Zirconia Wing Bridge

Overview

This study is a clinical trial to determine the retention and durability of the anterior zirconia wing bridge. The type of zirconia-wing bridge the investigators are researching in this study has two wings which generally have three countersunk holes (meaning that the circumference of the outer portion of the hole is larger than the inner part of the hole). Composite resin (dental filling material) is placed in the holes as well as under and around the wings. Twelve patients will have bridges placed and be evaluated every 6 months (ideally) to determine if the bridge is staying in place (retention) and if it is resistant to fracture (durability).

For patients missing an anterior tooth, the treatment options available include a dental implant, a removable partial denture, or a bridge. Some patients may not desire an implant due to the surgical nature, the limited bone available or the high cost. Removable partial dentures are relatively inexpensive but are undesirable for many patients due to the limited esthetics, trouble speaking and annoyance of an oral prosthesis. Traditional bridges use adjacent teeth as abutments and replace the missing tooth. However, these require the removal of 1-2 mm of tooth structure on adjacent teeth provide room for the porcelain of the bridge. Decades ago, the option for a conservative bridge was primarily found in the Maryland bridge, which had two metal wings that were cemented or bonded on to two abutments. Though conservative, the Maryland Bridge did not enjoy a high reputation because of the high rate of debonding (falling off). In the last several decades, the use of zirconia as a restorative material in dentistry has dramatically risen due to its toughness, resemblance in color to natural teeth, and affordability. Also, composite resin bonding agents (adhesive for dental fillings) have increased in strength and effectiveness. With these two advancements, the possibility of overcoming the some of the previous shortcomings with the Maryland Bridge is more of a reality. The type of zirconia-wing bridge we are researching in this study has two wings which generally have three countersunk holes (meaning that the circumference of the outer portion of the hole is larger than the inner part of the hole). Composite resin (dental filling material) is placed in the holes as well as under and around the wings. In summary, the zirconia-wing bridge presents a desirable alternative to traditional options for missing anterior teeth. With the advancements in resin-bonding and zirconia, this study seeks to examine how these combined elements can be used in the zirconia-wing bridge to maximize durability and retention in clinical scenarios.