Effects of Long‐Term Simulated RPD Clasp Attachment/Detachment on Retention Loss and Wear for Two Clasp Types and Three Abutment Material Surfaces

Abstract

The composite resin contoured surfaces showed more wear than the enamel and ceramic surfaces. E-clasps caused more wear on the abutment materials than back-action clasps.

Effect of Clasp Design on Retention at Different Intervals Using Different Abutment Materials and in a Simulated Oral Condition

“…A detailed analysis of clasp retention loss over time based on a previously published study was carried out to provide an explanation regarding the gradual loss of retention forces of the direct retainers (E‐circlet, back‐action). This study involved simulated cycles of attachment‐detachment at different intervals (0, 250, 500, 1000, 2000, 4000, 8000, and 16,000 cycles) and on different abutment materials (enamel, composite resin, and CAD/CAM ceramic) and also compared the retention force of circlet (E) clasp and back‐action clasp in a simulated oral condition.…”

“…The loss of retention and wear of two clasp types (E‐circlet, back‐action) against three abutment materials after 16,000 simulated cycles of attachment‐detachment has been reported . However, this report did not analyze the gradual loss of retention of the direct retainers (E‐circlet, back‐action) on different abutment material surfaces at different intervals.…”

“…Although removable partial dentures (RPDs) are favored options for restorations in many situations involving partial tooth loss, some patients are not satisfied with an RPD, especially when it is not stable during mastication . As a result, sufficient retention of RPDs is considered one of the most important factors affecting their clinical success …”

“…1 As a result, sufficient retention of RPDs is considered one of the most important factors affecting their clinical success. 2 Various clasp designs for achieving sufficient retention for RPDs have been discussed. [3][4][5][6][7][8][9][10][11] The long-arm clasps (roach, back-action, reverse back-action, modified ring, and extended arm varieties) have more retentive force than short-arm clasps.…”

Retentive forces and fatigue resistance of thermoplastic resin clasps

“…In previous similar studies [6,27,33], simulating test has been performed on a masticatory simulator, and clasp retention has been measured every cycling sequence using another machine (tensile testing machine). To get the clasp on the two machines every time in the exact same position is very difficult, this could produce greater load on the abutments and lead to retention loss in a short time.…”