Universitat Politecnica de Catalunya, Barcelona, Spain.
Int J Oral Maxillofac Implants. 2012 Jan-Feb;27(1):64-8.
This study sought to determine whether the mechanical properties of titanium dental implants changed after exposure to bacteria.
Two strains of bacteria (Streptococcus sanguinis and Lactobacillus salivarius) were used in the study. The adhesive properties of the two strains were investigated as follows. Titanium implants were placed in bacteria broth, seeded with the two bacteria strains, and left in the broth for 1 or 3 months. Another group of titanium implants was immersed in artificial saliva at 37°C for 3 months. Ten implants in each group were tested in 37°C artificial saliva to evaluate their mechanical flexural strength and fatigue life.
The bacterial cultures grew quickly on titanium surfaces. After 1 month of bacteria culture in vitro, the bacteria had produced corrosion pits on the titanium surfaces. After 3 months of bacterial culture, a 7% decrease in the flexural strength of the implant samples and a decrease of 15% in the number of cycles to failure by fatigue were seen versus implants not exposed to bacteria.
These results demonstrate that, in physiologic conditions in vitro, bacteria have the capacity to produce a pitting corrosion phenomenon on exposed titanium surfaces, leading to a significant deterioration in the mechanical properties of the implant. It is therefore logical to conclude that bacteria may produce corrosion that reduces the useful life of dental implants.
本研究旨在确定钛牙科种植体在暴露于细菌后其力学性能是否发生变化。
本研究使用了两种细菌（血链球菌和唾液乳杆菌）。研究了这两种细菌的粘附特性，具体操作如下：将钛种植体置于细菌培养液中，接种两种细菌菌株，并在培养液中放置 1 或 3 个月。另一组钛种植体则在 37°C 的人工唾液中浸泡 3 个月。每组中的 10 个种植体在 37°C 的人工唾液中进行测试，以评估其机械弯曲强度和疲劳寿命。
细菌在钛表面上迅速生长。体外细菌培养 1 个月后，细菌在钛表面产生了腐蚀坑。经过 3 个月的细菌培养，与未暴露于细菌的种植体相比，种植体样本的弯曲强度下降了 7%，疲劳失效的循环次数减少了 15%。
这些结果表明，在体外生理条件下，细菌有能力在暴露的钛表面产生点蚀腐蚀现象，导致种植体机械性能显著恶化。因此，可以合理地得出结论，细菌可能会产生腐蚀，从而缩短牙种植体的使用寿命。
