臨床評估不同製程技術及後腭封區型態對上腭全口 義齒固持力及密合度的影響 體內實驗

Abstract

實驗目的： 本研究目的在測試以以不同製程技術製作全口義齒時，固持力與密合度及義齒後腭封區 (posterior palatal seal)型態之相關評估。 材料與方法： 本實驗招募了九位上顎無牙的受試者 (2位男性; 7位女性, 平均年齡64.5歲)。使用客製化印模托進行邊緣成形後以矽膠印模材(Express XT Light body; 3M)進行精確印模。將製作出來的上顎模型進行桌掃(E3; 3Shape A/S)，並使用模擬設計軟體(Dental system 2020; 3Shape A/S)設計厚度為2mm之義齒基底試品，並調整邊緣及拋光面(polishing surface)型態。每位受試者會有五個不同製成的義齒基底，其中有一個傳統熱聚合樹脂(Lucitone 199; Dentsply Intl [Con]), 兩個數位切削 (Yamahachi PMMA clear; Yamahachi Dental MFG [Mil], [Mil-P]), 和兩個3D列印 (Enlighten AA temp, Enlighten materials co [Prt], [Prt-P])的義齒基底。其中數位切削和3D列印的義齒基底，又分為有後腭封區 (posterior palatal seal) 的Mil-P 組和Prt-P 組，和沒有後腭封區 (posterior palatal seal) 的Mil組和Prt 組。使用萬能測試機 (universal testing maching) (TD-221; JobHo Technology)和一個客製化的面弓(Mega) 組合作為拉力測試的施力裝置，來測量固持力(retentive force) (gw)，拉伸速率設定為50mm/min。每個義齒基底會進行三次拉力測試，每次測試之間間隔一分鐘。平均固持力將會使用廣義估計方程式(Generalized estimating equation）來進行統計分析 (α=.05)。關於密合度的部分，所有的義齒基底(共45個)使用桌掃機(E3; 3Shape A/S)進行掃描，得到義齒基底之立體結構檔案(STL檔)，並進行義齒基底之組織面與初始設計檔差距之比較。使用疊合軟體將義齒基底之組織面與設計檔進行疊合，先於軟體中定義出組織面貼合之範圍，而後將設計檔之組織面以及義齒基底組織面進行最佳疊合(best fit alignment)。疊合之後以軟體分析兩者之間的立體空間差距，並以均方根誤差(root mean square)代表誤差大小。誤差大小使用廣義估計方程式(Generalized estimating equation）來進行統計分析 (α=.05)，若組之間有顯著差異再使用最小顯著性差異法(Least Significant Differnece) 進行事後檢定。並將不同組測得均方根誤差數值與拉力測試數值進使用一致性相關係數(Lin’s concordance correlation)來進行相關性評估，得到一致性相關係數rc， 值域落在-1與1之間，若為-1則表示兩儀器之間完全不一 致；為0則表示彼此間互相獨立；為1則表示兩者之間完全一致。 實驗結果： 比較不同製成的義齒基底固持力，Con組(1669gw)和Mil-P組(1593gw)的平均固持力之間並沒有顯著差異。而這兩組的固持力都高於Prt-P組(853gw)。比較義齒基底有無後腭封區，固持力是否產生差異，不論是Mil 組(14 22gw) 和Mil-P 組(1593gw)之間，或是Prt組 (840gw) 和Prt-P 組(853gw)之間，都沒有顯著差異。關於密合度的部分，Mil-p組有最佳的密合度(RMS = 0.049mm)，而Con 組(RMS = 0.124mm)和Prt-P 組(RMS=0.149mm)之間則沒有顯著差異 (P<0.05)。固持力和密合度之間的一致性相關係數，分別為0.0036(Con), -0.00033(Mil), 0.00002(Mil-P), -0.01139(Prt), -0.00559(Prt-P)。從以上結果可之固持力和密合度之間相互獨立。 結論： 在本實驗有限的條件下，推論出以下的結論： 1. 傳統熱聚合樹脂和CAD/CAM milling PMMA製作的義齒基底，固持力沒有顯著差異，3D printing的臨床固持力表現最差。 2. CAD/CAM milling PMMA以及3D prinitng製作的義齒基底，有無後腭封區對固持力沒有造成顯著差異。 3. CAD/CAM milling PMMA製作的義齒基底密合度最佳，傳統熱聚合樹脂和3D printing 之間則沒有顯著差異。 4. 受試者對於不同製成的義齒基底，舒適滿意度沒有明顯差異。

Objective: This in vivo study was to evaluate the effects of different fabrication techniques (conventional press molding, CAD/CAM milling, and 3D printing), and posterior palatal seal design on the retention of the denture base. Material and methods 9 participants (2 male; 7 female, average 64.5yrs) with completely edentulous maxillary arches were enrolled in this study. Impressions were taken in the individual tray using the PVS impression material (Express XT Light body; 3M) after border molding. The maxillary master casts were scanned (E3; 3Shape A/S) and denture bases were designed by CAD simulation design software (Dental system 2020; 3Shape). Each participant had 5 denture bases made of different fabrication techniques and materials including: conventional press molding (Lucitone 199; Dentsply Intl [Con]), CAD/CAM milling (Yamahachi PMMA clear; Yamahachi Dental MFG [Mil], [Mil-P]), and 3D printing (Enlighten AA temp, Enlighten materials co [Prt], [Prt-P]). For CAD/CAM milling and and 3D printing denture bases, we divided them into 4 subgroups according to the design of posterior palatal seal: Mil group and Prt group were denture bases without posterior palatal seal while Mil-P group and Prt-P group were those with posterior palatal seal. A universal testing machine (TD-221, JobHo Technology) and a custom-designed facebow (Mega) were used as a force-applying device to measure denture retention (gw). The crosshead speed was set at 50 mm/min. Each denture base was subjected to a vertical pulling force 3 times at 1-minute intervals. The average retention of the 5 different denture bases was compared using Generalized estimating equation (α=.05). To evaluate the adaptation, all the denture bases were scanned with a table scanner (E3; 3Shape A/S) to obtain the three-dimensional structure file (STL file). After superimposing between the denture base file and the initial design file, the three-dimensional space gap was analyzed by image analysis software (Geomagic Control X 2020), and the root mean square (RMS) was calculated to represent the adaptation error. Results About the retention there was no significant difference between the Con group(1669gw) and the Mil-P group (1593gw). Both Con group and Mil-P group were significantly higher than the Prt-P group (853gw). There was no significant difference between Mil (14 22gw) and Mil-P (1593gw) or between Prt (840gw) and Prt-P (853gw). The results of adaptation showed that the Mil-p group had the best adaptation (RMS = 0.049mm). There was no significant difference between the Con group (RMS = 0.124mm), and the Prt-P group (RMS=0.149mm) (P<0.05). The concordance correlation coefficient rc values between retention and RMS are 0.0036(Con), -0.00033(Mil), 0.00002(Mil-P), -0.01139(Prt), -0.00559(Prt-P). The result showed that retention and adaptation are independent. Conclusions Within the limitation of the study, the conclusions are 1. The CAD/CAM milling denture bases presented similar retention with the conventional press molding denture bases, followed by the 3D printing denture bases. 2. There is no significant difference between the retention of denture bases with or without the design of posterior palatal seal. 3. The CAD/CAM milling denture bases showed better adaptation than the conventional press molding denture bases and the 3D printing denture bases. There was no significant difference between Con group and Prt-P group. 4. There is no significant difference between the satisfaction of different denture bases.