OBJECTIVEThis study aimed to investigate the duration of gingival healing after the stage II surgery of dental implantation for periodontitis patients and to provide clinical guidelines for implant restoration.

METHODSTwenty-nine periodontitis patients who had implantation surgery and achieved osseointegration were operated with stage II surgery (a total of 60 pieces of implants). The height of buccal gingival of each implant was measured twice after the stage II surgery. All implants were measured at the lowest point ofbuccal gingival after one week. The implants were randomly divided into four groups according to the schedule of the next test time: group one at one week from the initial test point, group two at two weeks, group three at three weeks, and group four at four weeks. Each group includes 15 pieces of implants. The amount of the buccal gingival change in each group between the second and first tests was determined, and the data were analyzed statistically.

RESULTSThe amount of gingival change of groups one, two, three, and four was (-0.25 +/- 0.66), (-0.04 +/- 0.52), (-0.70 +/- 0.77), and (-0.74 +/- 1.09) mm, respectively. No significant difference was observed between groups one and two in terms of the amount of gingival changes (P > 0.05). However, a significant difference was found between groups two and three (P < 0.05), and the amount of gingival recession was 0.66 mm. No significant difference was found between groups three and four (P > 0.05), and the gingival achieved stability.

CONCLUSIONThe gingival recession achieves stability at the fourth week (after 28 d) after stage II surgery. At this time, the implant can be restored, and the abutment can be selected according to the amount of gingival change of the periodontitis patient.

Alveolar Bone Loss ; Dental Implantation ; Dental Implantation, Endosseous ; Dental Implants ; Dental Restoration Failure ; Gingiva ; Gingival Recession ; Humans ; Osseointegration ; Periodontitis

Objective To determine the electrocardiographic (ECG) characteristics of myocardial infarction (MI) evolution in rats and the intervention effect of Chinese herbs, and to provide basis for the establishment of the criteria for ECG diagnosis and assessment of drug therapeutic effects of rats MI. Methods Totally 140 male SD rats were randomly divided into sham operation group, model group, replenishing qi group, activating blood group, replenishing qi and activating blood (1∶2) and (2∶1) group as well as Tongxinluo group, each group with 20 rats. The rat MI model was established by ligating the left anterior descending coronary artery. The treatment groups were administrered with corresponding drugs by gavage from the first day after operation. The sham operation group and model group were given the same volume of distilled water. The 12-lead ECGs were recorded before, immediately after, 1st and 2nd week after operation respectively. The voltage value of ST segment deviation, the time limit of QRS complex and the number of animals with pathologic Q wave were evaluated for statistical analysis. Results Model group showed the elevation of ST segment, significantly prolonged time limit of QRS complex (P<0.01), and no pathologic Q wave showed immediately after operation compared with sham operation group. And all above observational indexes reached the peak at 1st week and declined at 2nd week after operation. Compared with model group at 2nd week after operation, replenishing qi and activating blood (1∶2) group and (2∶1) group all presented remarkable dropping of ST segment, shortening in time limit of QRS complex and reduction in number of rats with pathologic Q wave, of which 2∶1 group showed the most (P<0.01). Activating blood group only displayed decreases in time limit of QRS and number of rats with pathologic Q wave (P<0.05), and no significant decline in ST segment. Replenishing qi group demonstrated no significant changes in above three observational indexes (P>0.05). Thus, we proposed the criterion for the ECG diagnosis of rats MI as well as the criterion for the ECG assessment of drug therapeutic effects of rats MI. Conclusion ECG can overall and sensitively evaluate the evolution and drug therapeutic effects of MI in rats, thus providing a relatively objective and available assessment method for the experimental studies of myocardial ischemic diseases.

Objective: To observe the material basis and mechanism of action of Kai-Xin-San (KXS) in regulating antidepression of neurotrophic factors. Methods: KXS eluted by ethanol on macroporous resin was prepared. The antidepressive effect of different components was compared by tailing suspension test and forced swimming test of mice. The levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in hippocampus were determined by ELISA. The rat astrocyte glioma C6 cell line and the rat adrenal pheochromocytoma PC12 cell line were used to evaluate the effects of different ethanol elution sites on the expression of NGF and BDNF and the differentiation of PC12 cells.Results: All of the ethanol elution components from KXS exerted anti-depressive effects by shorting the immobile time of tailing suspension and forced swimming of mice and 70％ ethanol elution components exerted best efficacy. This site also could increase expressions of NGF and BDNF on C6 glioma cell line. The 10％ ethanol elution site had the strongest ability to promote PC12 cell differentiation. Ginsenosides were the main effectuve ingredients for promoting the expression of neurotrophic factors. Conclusion: Regulation of neurotrophic factors might be the prominent action mechanism of KXS exerting anti-depressive effects.