| 0200 Retentive force properties of overenture attachments during various dislodging patterns | ||
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V. RUTKUNAS, Tokyo Medical & Dental University, Vilnius University, Japan, and H. MIZUTANI, Tokyo Medical & Dental University, Japan Objectives: To evaluate and compare resistance of mechanical (Era Overdenture, Zest Locator, OP anchor No. 4) and magnetic attachments (Hyperslim 4513 and 4013, Magfit EX600, Magnedisc 800, dome-shaped RK) to vertical and rotational dislodgments in mandibular overdenture model. Measure values of retentive energy of each type of attachment. Methods: Retentive properties were evaluated using 12 specimens of each type attachment. 10 measurements performed on mandibular model with imitated periodontal ligament and mucosa by universal testing machine (AGS-H, Shimadzu Co., Kyoto, Japan) with 50 mm/min cross head speed. Maximum retentive force and retentive energy evaluated in vertical linear dislodgement and rotational dislodgement (anterior, lateral and posterior) tests. To imitate rotational dislodgement attachments were embedded into framework reinforced acrylic overdenture. Statistical analysis: one-way ANOVA and Scheffe post-hoc tests. Results: For all tests ANOVAs were significant. Vertical dislodgement test revealed that most retentive were Era attachments (12530+/- 1576 mN, 8.5+/- 1.6 Nmm), followed by Locator (10745+/- 2330mN, 5+/-0.09 Nmm), Hyperslim 4513 (6065+/- 284 mN, 1+/-0.07Nmm), Hyperslim 4013 (4680+/- 147 mN, 0.5+/-0.03 Nmm), dome-shaped RK (4630+/-193 mN, 0.7+/-0.08 Nmm), Magnedisc 800 (4239+/-234 mN, 0.6+/-0.04 Nmm), Magfit EX600 (4179+/- 176 mN, 0.5+/-0.02) and O-ring (3460+/- 114 mN, 2.7+/-0.14 Nmm). Although these results corresponded with one obtained from rotational dislodgement tests, magnetic attachments showed considerable loss of retention during distal dislodgement. Attachments owing higher retentive energy provided better resistance to lateral and distal dislodgements. Conclusions: Though retentive force during vertical dislodgement of magnetic attachments is quite similar to mechanical ones, during rotational dislodgments their resistance properties are decreased. Resistance to rotational movements provided by attachment can be considerable factor improving overdenture retention and stability. Low retentive energy of magnetic attachments favors preservation of abutments. Attachments with proper values of retentive force and energy should be selected in particular clinical situation. | ||
| Seq #31 - Arthur R. Frechette Research Award Finalists 2:00 PM-4:00 PM, Wednesday, 10 March 2004 Hawaii Convention Center 321-B | ||
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