BACKGROUND: Micro-implant screws as an absolute anchorage, instead of traditional anchorage that requires patient's high matching and affects beauty, has been paid more attention.OBJECTIVE: To compare the changes in 3 different places following implantation of micro-implant screws. DESIGN, TIME AND SETTING: The controlled study was performed at the Hospital of Stomatology Affiliated to Foshan College of Sciences and Technology from January 2004 to December 2007.PARTICIPANTS: A total of 45 patients who demand powerful anchorage during the orthodontic treatment were assigned to 3 groups: free gingiva group, mucogingival junction group, and mucosa group.METHODS: By using incomplete flap micro-implant screw implantation, micro-implant screws were implanted in the free gingiva, mucogingival junction and mucosa, with 30 screws in each area.MAIN OUTCOME MEASURES: Loosening and defluvium of micro-implant screws were measured. Pain duration and degree were determined in patients undergoing implantation of micro-implant screws 7 days following surgery. Soft tissue surrounding the micro-implant screws and bleeding rate during probing were detected 56 days following surgery.RESULTS: The number of screw loosening was greatest in the free gingiva group (9 screws), while lowest in the mucogingival junction group (2 screws). Patients suffered from severe flare and pain in the mucosa, and the reaction was mild in the free gingiva following implantation. The reaction was not obvious, but severe pain was found in the mucogingival junction following implantation compared with the free gingiva. Soft tissue surrounding the micro-implant screws and bleeding rate during probing were greater in the mucosa group than in the free gingiva group and mucogingival junction group (P<0.05).CONCLUSION: The incomplete flap micro-implant screws in the mucogingival junction contribute to the increase in success implantation rate and the decrease in inflammatory degree, and prevent the occurrence of potential risk.

Recently, returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution. Meanwhile, the slow decomposition of straw may harm the growth of the next crop. This study aimed to determine the effects of rumen microorganisms (RMs) on straw decomposition, bacterial microbial community structure, soil properties, and soil enzyme activity. The results showed that RMs significantly enhanced the degradation rate of straw in the soil, reaching 39.52%, which was 41.37% higher than that of the control on the 30th day after straw return. After 30 d, straw degradation showed a significant slower trend in both the control and the experimental groups. According to the soil physicochemical parameters, the application of rumen fluid expedited soil matter transformation and nutrient buildup, and increased the urease, sucrase, and cellulase activity by 10%‒20%. The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid. The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability, which was the main reason for the accelerated straw decomposition. Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw, proposing a viable solution to the problem of sluggish straw decomposition.
Animals ; Rumen/metabolism* ; Agriculture/methods* ; Soil/chemistry* ; Microbiota ; Bacteria/metabolism* ; Oryza/metabolism* ; Soil Microbiology ; Cellulose