Weerkamp A H, van der Mei H C, Busscher H J
J Dent Res. 1985 Oct;64(10):1204-10. doi: 10.1177/00220345850640100501.
Contact angle measurements on layers of bacteria were used to determine the bacterial surface free energy (gamma b) of a variety of oral streptococcal strains, both without and after being coated with human whole saliva. At least four isolates of each species, either freshly isolated or laboratory strains, were used. The species Streptococcus mutans, S. sanguis, and S. salivarius were homogeneous, having high surface free energies, and were not affected by saliva treatment (gamma b = 106 +/- 12 and 107 +/- 10 erg X cm-2 in the absence and presence of saliva coating, respectively; n = 20). S. mitis had a very low surface free energy (46 +/- 15; n = 5), which was significantly increased after salivary adsorption (71 +/- 14 erg X cm-2; p less than 0.002). The species S. milleri contained strains with both high and low gamma b. Calculation of the interfacial free energy of adhesion (delta F adh) for bacteria from a saliva suspension to solid surfaces with various arbitrary surface free energies (gamma s) showed that, theoretically, most strains will encounter thermodynamically favorable conditions for adhesion to surfaces with a gamma s above 62 erg X cm-2. However, S. mitis strains not coated with saliva would only be able to adhere to surfaces with gamma s lower than this value. Saliva-coating reverses the calculated relationship with gamma s for these strains. The results indicate that an enamel surface with a low gamma s value would be thermodynamically unfavorable for adhesion of most oral streptococci.
通过测量细菌层的接触角来确定多种口腔链球菌菌株在未涂覆和涂覆人全唾液后的细菌表面自由能（γb）。每种菌株至少使用四个分离株，包括新分离的菌株或实验室菌株。变形链球菌、血链球菌和唾液链球菌具有均一性，表面自由能较高，且不受唾液处理的影响（未涂覆唾液和涂覆唾液时γb分别为106±12和107±10尔格×厘米-2；n = 20）。缓症链球菌的表面自由能非常低（46±15；n = 5），唾液吸附后显著增加（71±14尔格×厘米-2；p < 0.002）。米勒链球菌包含γb值高和低的菌株。计算来自唾液悬浮液的细菌与具有各种任意表面自由能（γs）的固体表面之间的粘附界面自由能（δFadh）表明，理论上，大多数菌株在γs高于62尔格×厘米-2的表面上会遇到热力学上有利的粘附条件。然而，未涂覆唾液的缓症链球菌菌株只能粘附到γs低于该值的表面。唾液涂层会逆转这些菌株与γs的计算关系。结果表明，γs值低的牙釉质表面在热力学上不利于大多数口腔链球菌的粘附。
