新式蠟/復形樹脂技術應用於一體式多單位固定式局部義齒 (小規模前期性研究)

One-piece multiunit fixed partial dentures via a new wax/pattern resin technique (A small-scale pilot study)

林永泓(Yung-Hung Lin)

指導教授 ： 鄧延通

高雄醫學大學/口腔醫學院/牙醫學研究所碩士在職專班/碩士(2011年)

摘要

中文摘要
研究目的：
使用嵌體蠟(inlay wax)在活動式單齒模(removable individual dies)上，製作一體式多單位長距徑固定義齒，已成為常規的牙科臨床操作和技工標準之習慣性方式。但是經常得到的結果是產生扭曲、變形和明顯縫隙在牙冠的邊緣上；隨後，需要多重的檢查步驟來進行再加工，例如：切割分段和重新於患者口腔內定位後再進行焊接程序，最後才能完成再裝置於病患口腔內，反而存在更多問題 。本研究的目的是介紹一種改良式的蠟型結合冷凝自聚式樹脂的技術，應用於完整牙模與獨立單齒模上，來製作一體式不需要焊接的多單位固定式義齒；並且評估絕對值邊緣間隙(absolute marginal discrepancy, AMD)，預期達成ADA建議邊緣精密度≦ 50 um 以下的共同標準。
研究材料與方法：
使用完整牙模與獨立單齒模，製作一體式多單位固定式義齒支架 ，各5個重覆組別，設計如下：傳統式獨立單齒模與完整牙模，為對照組(WI/WS, n=5)，使用蠟型方式製作；改良式獨立單齒模與完整牙模，為實驗組(MI/MS, n=5)，使用蠟/復形樹脂方式製作；所有組
別分別包埋、鑄造為金屬支架，最後在40個各別相對應的工作模型上進行精修程序完成。使用光學立體顯微鏡分別照像記錄 (WI/MI)、(WS/MS)： 12、13、23、 24 (FDI system 分類法)，支台齒上最大AMD縫隙圖像，再利用電腦圖像分析軟體進行邊緣測量與計算。由此產生的數據使用統計軟體SPSS 13.0進行 paired-t 檢定，α值設定為0.05，比較兩組之間統計上的差異。
實驗結果:
根據電腦圖像採集和分析絕對值邊緣縫隙(AMD)最大值在兩個組別四個區域：頰側(B)、舌側(L)、近心側(M)和遠心側(D)，共320個測量值顯示：在獨立單齒模上，對照組WI (總計80個數值) 最大AMD值為73.18 ?慆，達50 ?慆以下成功率為90％；實驗組MI (總計80個數值) 最大AMD值為33.82 ?慆，達50 ?慆以下成功率為100％；在完整牙模上，對照組WS (總計80個數值) 最大AMD值為433.09 ?慆，達50 ?慆以下成功率為36.25％；實驗組MI (總計80個數值) 最大AMD值為51.65 ?慆，達50 ?慆 以下成功率為98.75％ 。在配對t 檢定包含所有B、L、M、D四個區域顯示：WI-MI 、 WS-MS、WS_B-WS_L、WS_M-WS_D、MS_B-MS_L呈現 P <0.05 顯著性差異；其他均無顯著性差異。
結論：
在本實驗的限制條件下，我們初步研究每組各五個重複組別，提供簡要地概括如下：分析和評估在獨立單齒模與完整牙模上製作不需焊接的多單位長距徑固定義齒結果顯示：i) 傳統蠟型方式在獨立單齒模與完整牙模上製作，確實很難達到邊緣縫隙值較小與不變形、扭曲的結果；ii) 我們提出的改良式蠟與復形樹脂合併製作方式 ，明顯得到較低的邊緣縫隙值和較高的成功率，呈現令人滿意的結果 。因此，這個新穎的技術或許能被應用在現代牙科實驗室的製作上，以取得更好的臨床成果。

關鍵字

嵌體蠟 ； 多單位長距徑固定義齒 ； 活動式單齒模具 ； 冷凝自聚式複合樹脂 ； 完整牙模與獨立牙模

並列摘要

Abstract
Objective:
It has been a customary or routine standard to produce a multiunit long-span fixed partial denture through the processing of one-piece casting over removable individual dies and inlay wax, where it usually yields distortions, twists and significant gaps on the margins of the fabricated protheses. Subsequently, these tedious laboratory multi-steps will require further re-processing such as sectioning or/and re-soldering of the products to be re-oriented into the patient’s mouths before final delivery, which often end up with more clinical problems. The aim of the present study was to introduce and to assess the feasibility of a revised or re-modified wax-pattern combined with self-cured resin technique (called: pattern resin) featuring one-piece casting over the individual dies with solid cast without soldering prior to producing the multi-unit fixed partial dentures, which is expected to manifestly fulfill ― 50 ?慆 ‖ professional standards set for assessing the ―absolute marginal discrepancy‖(AMD). on the fabricated crown margins as recommended by the ADA (American Dental Association).
Materials & Methods:
For fabricating the multiunit fixed partial denture via one-piece casting on individual dies with solid cast without soldering, each of the five replicates per group was designed as follows: the traditional approach using a wax-pattern method on individual dies and solid casts was ― the control ‖ group (WI/WS, n=5) and our revised/ re-developed wax/pattern resin method was set as ― the experimental ‖ group (MI/MS, n=5), each of which in total of 40 corresponding units were then further processed for subsequent embedment, casting into metal frameworks and the final refinements. The resulting ― maximal ‖ AMD on each of the buccal (B), lingual (L), mesial (M) and distal (D) margins on the abutments, (WI/MI), (WS/MS): 12, 13, 23 & 24 (FDI system) were separately recorded by using the optical stereo-microscope for images, then by using computer through the build-in software for scanning & image analyses. The resulting data sets were analyzed by SPSS13.0
software and the paired-t test was employed for statistical comparisons between both groups where α value was set 0.05.
The results:
Based on the computer images acquired and subsequent analyses obtained from both groups, the results of assessing the ― maximal ‖ absolute marginal discrepancy (AMD) in the four areas: B, L, M & D, a totaling of 320 measurements, showed that: on individual dies, the mean AMD value for WI in the control group (total=80) was 73.18 um with the averaged success rate of 90% (by reaching 50 ?戥m); whereas the mean AMD for MI in the experimental group (total=80) was 33.82 ?慆 with the averaged success rate of 100% (by reaching 50 ?慆). And, on solid casts, the mean AMD value for WS in the control group (total=80) was 433.09 ?慆 with the averaged success rate of 36.25% (by reaching 50 ?慆), whereas the mean AMD for MS in the experimental group (total=80) was 51.65 ?慆 with the averaged success rate of 98.75% (by reaching 50 ?慆). Meanwhile, the results of paired-t test involving all four B, L, M & D areas showed that there were statistically significant differences between WI-MI, WS-MS, WS_B-WS_L, WS_M-WS_D & MS_B-MS_L for comparisons with P<0.05, respectively; while others showed no significant difference, individually.
Conclusion:
Under the experimental conditions studied, our preliminary pilot analyses with each of five replicates per group provided a rationalized support briefly summarized as follows: for the multiunit fixed partial denture fabricated by one-piece casting over the individual dies with solid cast without soldering, our analyses on assessing the resulting feasibility and accuracy indicated that: i) it is very difficult to achieve the satisfactory outcomes without significant marginal gaps or/and distortions(i.e., AMD values) via the traditional fashion of wax-pattern method on the individual dies with solid casts, and ii) our revised/modified mixed wax/pattern resin method demonstrates quite significantly less marginal discrepancy with much higher success rates for satisfactory laboratory results. Therefore, this revised new technique may have the potential to be applied in the modern dental laboratory to
achieve better clinical outcomes and efficacy in the future.

並列關鍵字

multiunit long-span fixed partial denture ； removable individual dies ； inlay wax ； self-cured resin ； individual dies with solid cast

參考文獻

參考文獻

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