研究目的：本研究探討經各種方法處理過後的牙本質，以及若在雷射處理完後再二次處理牙本質表面，其表面的型態變化與其和複合樹脂之間鍵結力強弱，並觀察破斷面。
材料與方法：收集無齲蛀之人類臼齒，分別以傳統磷酸處理，LinerBond II處理，SE Bond處理與Nd:YAP雷射處理。另外先經雷射處理後再以1.5% NaOCl，EDTA，及磷酸等三種方式處理。剪力測試法來測量其鍵結能力，再以SEM 來觀察其表面型態及破斷橫截面，。
結果：傳統磷酸處理後牙本質與複合樹脂間的剪強度比使用Liner Bond II處理及Nd:YAP雷射處理要來的高，使用SE Bond，Liner Bond II及Nd:YAP雷射處理後之剪強度沒有差異；雷射處理後再使用EDTA，NaOCl或是磷酸二次處理所獲得的剪強度與單獨使用Nd:YAP雷射處理皆沒有明顯的差異。
結論：牙本質不同的處理方式會導致其表面型態不同，牙本質小管開口數目，大小，剪強度皆不同。雷射具有封閉牙本質小管開口的能力，其鍵結能力與自身酸蝕系統相當。
Object: The purposes of this research were to study the shear bond strengths and morphological changes after different surface treatments of dentines, as well as under several conditions after laser irradiation.
Materials and Methods: Extracted human free-caries molars were stored in normal saline until used. Four different treatments, including phosphoric acid, Liner Bond II, SE Bond were carried out, and Nd:YAP laser treatments. Some specimens were assigned into three groups, such as NaOCl, EDTA, and phosphoric acid when laser irradiation was conducted previously. After surface treatments, these teeth were observed by using SEM, and tested with shear bond strength testing.
Results: The value of shear bond strength in phosphate group was higher than those in laser and LB II groups. There were not significantly different among laser, LB II, and SE Bond groups. After laser irradiation, the following NaOCl, EDTA, and phosphate retreatments indicated no statistically significant difference.
Conclusion: Different treatments made different morphologies, and shear bond strength values. Laser irradiation could seal dentinal tube, to be worth studying further.
