[Changes of cementum endotoxin levels in different teeth with periodontitis treated with root conditioning]

To observe the changes of endotoxin levels after different teeth with periodontitis were treated with different methods. METHODS： Six healthy premolars extracted for orthodontic reasons and 36 posterior teeth extracted due to severe periodontitis were selected. Each tooth was processed from two 4 mm×4 mm×1 mm cementum pieces 2 mm under the cementum-enamel junction, each tooth with periodontitis was numbered. Healthy teeth served as negative control group, one of the two tablets from each tooth with periodontitis was selected in the periodontitis group, which was not treated with root surface treatment. The remaining 36 teeth with periodontitis were randomly divided into 6 groups: SRP group, SRP + antimicrobial peptide A group , SRP + antimicrobial peptide B group, SRP + EDTA group, SRP + Er:YAG laser group and SRP + Nd:YAG laser group. Endotoxin concentration in each tooth was determined by chromogenic substrate limulus reagent. The endotoxin concentration in each tooth was recorded according to the serial number, and the changes of endotoxin concentration were calculated before and after treatment. SPSS17.0 software package was used to analyze the data.

Compared with the teeth with periodontitis, endotoxin concentration decreased to varying degrees, there were significant differences in each treatment group(P<0.01). Compared with SRP group, endotoxin levels in SRP + antimicrobial peptide A group, SRP + antimicrobial peptide B group, SRP + Er:YAG laser group were significantly decreased(P<0.01). No significant difference decreased was from between SRP + EDTA group and SRP + Nd:YAG laser group(P>0.05).

Treatment of teeth with periodontitis using different methods can decrease the level of endotoxin, and the treatment of periodontitis root surface with antimicrobial peptide A + SRP may be more effective.