| Summary: | 碩士 === 中山醫學院 === 口腔醫學研究所 === 89 === 英文摘要
Temporary soft-lining materials are frequently used in patients whose thickness of the alveolar bone in the edentulous areas appears thin and the elasticity becomes anomalous. This kind of alveolar ridge cannot bear the general resin denture base. Therefore, temporary soft-lining materials are used to reduce the bearing load of alveolar ridge. The use of temporary soft-lining materials increasingly has come into favor for various applications in prosthetic dentistry, including use with dental implants for promote surgical wound healing and retention. Nevertheless, it is time-consuming when substituting liners; worse, the replacement procedure may even damage the denture base. The purpose of this study was to assess the different surface bond strengths of denture base materials ( acrylic resin denture base- Lucitone 199a and visible light-cured denture base- Triada ) under various surface treatments and thermocycles conditions. The results may offer some insights into the feasibility of replacement of temporary soft-liners cliniclly.
Two denture base materials, Lucitone 199 ( Dentsply/York Division, York, Pa. ) and Triad ( Dentsply International Corporation, York, Pa. ), were used in this study. The size of each material is 75 mm×25 mm×2.5 mm . Total samples are 400 and divided into four groups ( 100/each group consisting of 50 Lucitone 199 and 50 Triad ) as follows: Group (A) No treatment; Group (B) Sandblast; Group (C)TC-SEPARATOR and Group(D) Sandblast treatment followed by TC-SEPARATOR. The thickness of specimens consisted of 2.5 mm of Lucitone 199 or Triad and 2.5 mm of Coe-Soft (GC Co ), being bonded over 25 mm of the length of the specimen and separated over the remaining 50 mm. Immediately the specimens were immersed in 37oC normal saline for 24 hours and then ten specimens in each group were dipped for 20 seconds in 4 o C and 55 o C normal saline with a travel time of 5 seconds for 0, 150, 300, 600, 1200 thermocycles. All of the specimens were subjected to a peeling force by separation of the serrated grips at a constant rate of 100 mm/min in an universal testing machine ( AUTOGRAPH AGE-1000E Shtmadzu,Japan ). The peel force and nature of failure for each specimen was recorded. A three-way ANOVA followed by a Tukey's test was used to analyze the data. The peel force of sandblast treated specimens had the highest value ( p<0.01 ). Denture base treated by sandblast + TC-SEPARATOR showed a higher peel force than that of treated by TC-SEPARATOR specimens but lower than that of no treatment and treated alone by sandblast specimens ( p<0.01 ). Statistically, the peel force of cycle 600, 0,300,150 specimens showed is significantly lower than that of cycle 1200 specimens ( p<0.01 ).
Taken together, the treatments of sandblast followed by TC-SEPARATOR do not damage the bonding force between either Lucitone 199 with Coe-Soft or Triad with Coe-Soft. The bond strength of the sandblast + TC-SEPARATOR is not too week to cause peeling off of denture base. The peeling force is only marginally below clinical scope. Overall, it is a feasible surface treatment on denture base materials based on the advantages of (1) easy replacement yet not causing peeling off; (2) time-saving and (3) maintaining denture base strength.
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