Objective  目的 

To compare how laser-microtextured implants and implants with platform switching maintain crestal bone stability in thin peri-implant tissues.
比較雷射微溝槽和Platform-switching的植體在較薄牙齦的條件下維持齒槽骨高度的能力。

Material and methods  材料和方法

Thirty laser-microtextured implants of 4.6 mm diameter (Tapered Internal Laser-Lok, BioHorizons, Birmingham, AL, USA; Group 1) and 30 implants with platform switching of 5/4 mm diameter (Certain Prevail; Biomet/3i, Palm Beach Gardens, FL, USA; Group 2) were placed in 30 patients (12 males and 18 females, mean age 42.3±2.4) with thin mucosal tissues (≤2 mm).Implants were placed in posterior mandible in one-stage approach and after integration were restored with screw-retained metal-ceramic restorations. Radiographic examination was performed after implant placement, 2 months after healing, at prosthetic restoration delivery and after 1-year follow-up. Mean crestal bone loss was calculated, Mann–Whitney U-test was applied, and significance was set to 0.05.
30支具有雷射微溝槽的植體，直徑4.6mm(Tapered Internal Laser-Lok, BioHorizons, Birmingham, AL, USA; 第一組)和30支具有platform switching的植體，直徑4或5mm (Certain Prevail; Biomet/3i, Palm Beach Gardens, FL, USA; 第二組)，分別在30位(12位男性 和 18 位女性, 平均年紀 42.3±2.4歲)牙齦組織較薄(≤2 mm)的病患身上植入，將植體以一階手術的方式植入在下顎後牙區，待骨整合後，以screw-retained的方式裝上金屬陶瓷的膺復體。在植入植體後拍攝X光片，待兩個月癒合後裝上假牙，並在裝上假牙一年後追蹤。利用Mann–Whitney U-test計算齒槽骨萎縮的程度，而數據基準設定在0.05。

Fig. 1. (a) Thin mucosal biotype before implant placement, (b) BioHorizons Tapered Laser-Lok implant with lasermicrogrooved neck to the top of the implant, (c) Position of both implants, (d) Healing abutments connected to implants during 1-stage surgery

Fig. 2. Crestal bone levels around BioHorizons Laser-Lok and Biomet/3i implants (a) after placement and (b)2 months of healing.

Fig. 3. Crestal bone loss around after restoration delivery (a) Biomet/3i implant, (b) BioHorizons Laser-Lok implant and after 1-year follow-up at (c) Biomet/3i, (d) BioHorizons Laser-Lok implants.

Results  結果

After 2 months of healing, the crestal bone loss was 0.71± 0.25 mm SD (range, 0.25–1.6 mm) and 1.02± 0.25 mm SD (range, 0.6–1.55 mm) in groups 1 and 2, respectively (P = 0.001).At restorations’ delivery, the crestal bone loss was 1.10 ±0.30 mm SD (range, 0.65–1.85 mm) and 1.37 ±0.27 mm SD (range, 0.90–1.80 mm) in groups 1 and 2, respectively (P = 0.001). After 1-year
follow-up, the crestal bone loss was 1.41± 0.42 mm SD (range, +0.1–2.30 mm) and 1.43± 0.23 mm SD (range, 1–1.80 mm) in groups 1 and 2, respectively (P = 0.976).
待兩個月癒合後，第一組和第二組齒槽骨萎縮的程度SD值分別為0.71± 0.25 mm(範圍0.25–1.6 mm)和1.02± 0.25 mm(範圍0.6–1.55 mm)，(P值=0.001)。裝上假牙後，第一組和第二組齒槽骨萎縮的程度SD值分別為1.10 ±0.30 mm(範圍0.65–1.85 mm)和1.37 ±0.27 mm (範圍0.90–1.80 mm)，(P值=0.001)。一年後追蹤，第一組和第二組齒槽骨萎縮的程度SD值分別為1.41± 0.42 mm(範圍+0.1–2.30 mm)和1.43± 0.23 mm(範圍 1–1.80 mm)，(P值= 0.976)。

Fig. 6. Crestal bone level around BioHorizons and Biomet/3i implants in thin tissue biotype: (a, c) after placement, (b, d) 1-year follow-up. Note no bone loss around laser-microtextured neck implants.

Conclusions   結論 

Laser-microtexturing of implant collar or platform-switched implant/abutment connection did not eliminate crestal bone loss, if at the time of implant placement vertical soft tissue thickness was ≤2 mm. However, laser-microtextured implants may present less proximal bone loss than platform-switching implants in the period before implant loading.
如果牙齦的垂直厚度小於2 mm，就算是有雷射微溝槽或platform-switching的植體，在loading後都無法有效的維持齒槽骨高度。然而，在還未loading前，雷射微溝槽植體比platform-switching植體能更有效的維持齒槽骨高度。