| 摘要: | 暫時性軟式墊底在臨床上常用於患者缺牙區黏膜的骨膜厚度很薄及彈性變差的情況，這類牙床無法承受一般樹脂義齒基底。利用暫時性軟式墊底可以減少對齒槽骨的負荷力。對於剛接受手術處理的牙床骨和口腔粘膜，暫時性軟式墊底的使用可減輕傷痕的刺激，促進復原。但在更換墊底時，技工操作費時，甚而會破壞樹脂義齒基底。本實驗的目的是在評估暫時性軟式墊底材料與經由不同表面處理之丙烯酸樹脂義齒基底及光凝式義齒樹脂基底其表面結構所產生鍵結強度的差異，並瞭解經過冷熱循環處理後，暫時性軟式墊底材料與丙烯酸樹脂義齒基底及光凝式義齒樹脂基底間鍵結強度的改變，以提供臨床上一種簡易的換暫時性軟式墊底材料的方法。
本實驗以Lucitone 199 ( Dentsply/York Division, York, Pa.) 及Triad ( Dentsply International Corporation, York, Pa.) 為義齒基底材料。製作試片尺寸為75 mm×25 mm×2.5 mm共400片。分為四組，每組各100片 ( Lucitone 199: 50片，Triad: 50片 )，Group A：表面不做任何處理，Group B：表面以直徑250μm大小顆粒之氧化鋁噴砂，Group C：表面塗上分離劑TC-SEPARATOR ( GC Co. )，Group D：表面先噴砂再塗上分離劑。經過表面處理的四組試片再與尺寸為75 mm×25 mm×2.5 mm的Coe-Soft ( GC Co. )共400片，在25mm處接合後，隨即浸入37oC生理食鹽水的容器中24小時，然後每一組再分為4個Subgroup ( 每一小組10片 )，每個Subgroup接受冷熱循環處理0次、150次、300次、600次及1200次，每一次循環包括4oC及55oC各20秒鐘，之後測驗其剝離力量並記錄之。以三因子變異數分析 ( three-way ANOVA ) 後再以Tukey''s test分析其差異情形。
結果發現經過氧化鋁噴砂的試片其剝離力量最強 ( p<0.01 )。義齒基底表面先噴砂再塗上分離劑其剝離力量強度大於與只在表面塗上分離劑的試片，但是明顯小於表面不做任何處理及表面只作噴砂處理的試片 ( p<0.01 )。經過冷熱循環處理1200後的試片其剝離力量明顯大於冷熱循環600、0、300、150次的試片 ( p<0.01 )。
綜合以上結果發現，合併使用噴砂加上塗TC-SEPARATOR這種表面處理方式，它們的鍵結強度不會太弱而很容易剝落，它們的剝離力量稍低於臨床上的範圍，不會脫落且容易更換，節省時間也不會影響義齒基底本身的強度，似乎是一種可供臨床上參考的表面處理方式。
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. |
