感覺適應於全導引植牙手術對植牙手感診斷骨質能力之影響

Abstract

實驗目的 骨質的軟硬一直被認為是影響人工植牙成功率的重要因子之一。過硬或過軟的骨質可能影響對於後續骨質判斷以及鑽骨策略，進而影響人工牙根植體植入時的初期穩定度、等待骨整合的時間以及植體的成功率。臨床上在不同骨質區植牙時，除了利用傳統放射線檢查或電腦斷層攝影提供一部分的骨質資訊，有經驗的手術醫師常輔助以鑽骨時的手感來診斷骨質以決定手術步驟與癒合時間，調整手術鑽孔步驟或方式例如「預攻螺紋」、「擴骨」、「較小尺寸預鑽孔」等術式以期得到較合適的人工牙根初期穩定度。此外，植牙區域也是影響植體治療成功的關鍵之一。日漸流行的全導引植牙手術(fully guided implant surgery)是使用術前電腦斷層配合口內掃描檔案或是石膏模型的桌掃檔案、依據將來植牙義齒的外型來規劃人工牙根的位置，並使用電腦設計製作 (CAD/CAM)手術導板，讓醫師在手術中可以全程用來確認植牙之位置、角度與深度。此方法可以增加手術安全度與減少手術時間。然而由於全導引手術導板上的引導套環與植牙鑽針緊密貼合而產生摩擦力，可能會影響到手感的判斷；更因於不同的骨密度下，手感判斷可能因為先前手感的經驗而造成失準，導致後續骨質判斷失誤。因此本實驗目的為探討有無使用全導引手術導板於先前骨頭硬度不同時，對於關鍵植牙位置是否會影響到手術醫師對骨質的判斷能力。將納入30名牙醫師做為受試者，利用四種不同密度的模擬骨塊，紀錄有無使用全導引手術導板鑽孔，合併先前鑽過不同骨質硬度之後，受試醫師判斷骨質硬度的精確性是否受到影響，藉此探討全導引手術導板和鑽骨前經歷不同骨質軟硬對於人工植牙手術診斷骨質的影響。 實驗材料與方法 本實驗納入30名牙醫師作為受試者，納入條件為執業年資未滿10年，臨床植牙經驗少於10顆，且年齡介於24至40歲。排除條件為無法配合完整測試流程者。實驗設計區分成徒手鑽骨以及全導引手術兩輪，每輪區分成中間骨質硬度軟硬中ABC三組，每一組有五次鑽骨測試。實驗模型以3Shape trio 4 口掃機取得，合併模擬病人的錐狀射束電腦斷層掃描(cone beam computed tomography, CBCT)的DICOM（Digital Imaging and Communications in Medicine）檔案設定出植牙位置。將模型透過Meshmixer（Autodesk Meshmixer, Autodesk, San Rafael, USA）軟體進行編輯，設計模擬骨塊置放之凹槽。模型凹槽處分別放置不同的模擬骨塊。每組模擬骨塊置放順序如下：編號Ａ模型為5，5，10 pcf；編號B模型為15，15，10 pcf；編號C模型為10，10，10 pcf。進行每組測試時，請受試者先鑽取一個50 pcf的模擬骨塊，告知此為最硬的模擬骨塊。接著鑽一個10 pcf的模擬骨塊，再依序鑽放置模型凹槽的模擬骨塊。第一輪為徒手鑽孔(Free hand drilling)，測試三組結束。等待一個月後，接續第二輪使用全導引手術導板（Fully guided drilling with stent）。每次鑽骨完成後，即在問卷上標記手感硬度，在長度為10公分的視覺評比量表（Visual Analogue Scale, VAS）上標記，再以標記處的線段長度（mm）做為VAS數值。此VAS數值即為受試者診斷模擬骨塊的硬度。 統計分析 數據於Microsoft Excel (V 14.1) 進行資料建檔，隨後匯入 SAS 統計分析軟體 (SAS System for Windows, V9.4, SAS Institute Inc., Cary, NC, USA) 執行後續統計程序。先進行常態性分析後，再進行配對t檢定(paired t test)評估是否有無統計上的顯著差異，所有的統計分析p value設定在< 0.05表示在統計學上有顯著意義。 實驗結果 本研究共納入30位牙醫師（年齡24–40歲；臨床經驗<10年；植牙經驗<10顆）。每位受試者皆完成六組鑽孔測試（徒手與全導引各三組），三組不同排列之骨塊中進行（A組：5,5,10 pcf；B組：15,15,10 pcf；C組：10,10,10 pcf）。每次鑽骨後，受試者以10 公分的視覺類比量表（VAS）紀錄其對骨質硬度之觸覺感受。 在徒手鑽孔條件下，中間骨塊密度變化對最終骨塊（10 pcf）之手感評估具有顯著影響。A組（中間變軟）中，第二次與第五次鑽孔VAS值成顯著差異（VAS差值為9.44±18.77, p <0.05）；B組（中間變硬）也具顯著差異（VAS差值為-8.22±17.8, p <0.05）。C組（骨質不變）前後則無顯著差異（VAS差值為1.71±15.33, p>0.05）。 在使用全導引手術導板條件下，A組（中間變軟）前後VAS有上升並有顯著差異（VAS差值為10.62±23.07, p<0.05）；B組（中間變硬）則無顯著差異（VAS差值為−2.99±18.62, p >0.05）；C組（骨質不變）亦無顯著差異（VAS差值為3.31±17.96, p> 0.05）。 此外，於骨質不變組（C組）中，受試者對相同10 pcf骨塊的鑽孔手感評估在使用全導引手術導板條件下顯著高於徒手鑽孔（VAS差值為-8.82±18.27, p> 0.05）。 對中間骨質變化對手感變化幅度的影響進行分析，結果顯示，雖然徒手與導板組在不同骨質條件下的手感變化量皆有顯著差異，但比較兩組手感變化幅度的差值，並無統計上的顯著差異（p > 0.05）。 結論 先前骨質變化會明顯影響手感，只有在使用全導引手術導板，並且先前鑽孔的骨質相對堅硬的情形下，才有手感沒有產生明顯偏差狀況。使用全導引手術導板會使得鑽骨手感偏移，診斷為較硬的骨質，但是面對骨質變化所造成的手感差異，和徒手鑽骨並無顯著差別。

Objective Bone quality was a critical factor for dental implant success, influencing initial stability and osseointegration. Clinically, surgeons often relied on tactile sensation during drilling to assess bone density and adapted surgical techniques (e.g., pre-tapping, bone expansion, undersized drilling), with supplemented radiographic data. Fully guided implant surgery, using CAD/CAM surgical guides based on preoperative CT and scan data, enhanced accuracy and safety. However, friction between the guide sleeve and drill may have impede tactiled feedback, and prior drilling experiences could have biased bone density perception. This study investigated if using fully guided surgical templates, under varying preceding bone hardness conditions, affected surgeons' bone quality assessment at critical implant sites. Thirty dentists were enrolled and drilled simulated bone blocks with different densities, both with and without a surgical guide, with previous exposure to different bone hardness. The study aimed to evaluate the impact of fully guided surgery and the varying bone hardness experienced before drilling on the bone quality assessment in dental implant surgery. Materials and methods This study enrolled 30 dentists as participants. Inclusion criteria were: less than 10 years of practice, clinical experience with fewer than 10 dental implants, and age between 24 and 40 years. The exclusion criterion was the inability to complete the entire testing procedure. The experimental design consisted of two rounds, with each round comprising three groups, and each group involving five drilling tests. Experimental models were acquired using a 3Shape TRIOS 4 intraoral scanner and merged with a simulated patient's cone-beam computed tomography (CBCT) scan and applied DICOM files(Digital Imaging and Communications in Medicine) to determine implant positions. The models were edited using Meshmixer software to create recesses for the insertion of simulated bone blocks. Different simulated bone blocks were placed into these model recesses. For each round, the A group's model contained blocks of 5, 5, and 10 pounds pcf (per cubic foot); the B group's model contained blocks of 15, 15, and 10 pcf; and the C group's model contained blocks of 10, 10, and 10 pcf. In each group of tests, participants first drilled a 50 pcf simulated bone block and were informed that this represented the hardest simulated bone. Subsequently, the experiment proceeded in sequence. Next, a 10 pcf simulated bone block was drilled, followed by sequential drilling of the blocks in the model. The first round involved three groups of conventional free hand drilling tests. After a 4 weeks washout period, the second round commenced, utilizing fully guided drilling with a surgical stent. After completing each drilling, participants recorded their perceived tactile hardness on a questionnaire using a 10 cm Visual Analog Scale (VAS). The length of the VAS was measured and converted into a value representing the bone hardness as perceived by the participant. Statistical analysis Data was initially recorded in Microsoft Excel (V 14.1) and subsequently imported into SAS statistical analysis software (SAS System for Windows, V9.4, SAS Institute Inc., Cary, NC, USA) for further statistical procedures. Normality tests were conducted first, followed by paired t-tests to evaluate statistically significant differences. For all statistical analyses, a p-value of < 0.05 was considered statistically significant. Results A total of 30 dentists (aged 24–40 years; clinical experience <10 years; implant experience <10 cases) participated in this study. Each participant performed six drilling tests (three freehand and three fully guided) on three different bone block arrangements (Group A: 5, 5, 10 pcf; Group B: 15, 15, 10 pcf; Group C: 10, 10, 10 pcf). After each drilling, participants recorded their tactile perception of bone density using a 10 cm visual analog scale (VAS). For the freehand drilling condition, changes in the density of the intermediate bone blocks had a significant impact on the perceived hardness of the final bone block (10 pcf). Specifically, in Group A (intermediate softening), a significant difference was found between the second and fifth drilling VAS scores (VAS difference: 9.44±18.77, p<0.05). A significant difference was also observed in Group B (intermediate hardening) (VAS difference: −8.22±17.8, p<0.05). In contrast, Group C (constant bone quality) showed no significant difference (VAS difference: 1.71±15.33, p>0.05). Under the fully guided drilling condition, Group A (intermediate softening) exhibited a significant increase in VAS scores (VAS difference: 10.62±23.07, p<0.05). However, no significant differences were found in Group B (intermediate hardening) (VAS difference: −2.99±18.62, p>0.05) or Group C (constant bone quality) (VAS difference: 3.31±17.96, p>0.05). Furthermore, within the constant bone quality group (Group C), the participants' tactile perception of the same 10 pcf bone block was significantly higher when using the fully guided surgical guide compared to freehand drilling (VAS difference: −8.82±18.27, p>0.05). An analysis of the effect of intermediate bone quality change on the magnitude of tactile perception change revealed that, although the freehand and guided groups both showed significant changes in tactile perception under different bone quality conditions, a comparison of the magnitudes of these changes between the two groups showed no statistically significant difference (p>0.05). Conclusion Variations in preceding bone quality significantly impacted tactile sensation. Only when using a fully guided surgical stent, and specifically after previously drilling in relatively hard bone, did the tactile sensation not exhibit significant deviation. The use of a fully guided surgical stent tends to alter the tactile perception during drilling, leading to a diagnosis of harder bone quality. However, the variation in tactile perception caused by experiencing varying bone densities prior to drilling showed no significant difference when compared to free hand drilling.