Objective To evaluate the clinical application of Straumman implant system in the upper anterior region.Methods 23 patients were implanted with 28 Straumman implants.Follow up of clinical observation and maitenance began after final crown restored.Bone resorption mesial and distal to the implant were recorded by periodical X-ray check.Soft tissue was observed and analyzed according to Jemet papilla index.Results Total survival rate of all the 28 implats was 100％.Alveolar bone resorptions between mesial part of the implant and distal part with loading after 0.5 year,1 year,2 years and 4 years had no stastical significance(t =0.689,0.686,0.694,0.705,all P ＞0.05).Interdental papillae around implant supported crown gained recovery after 2 years.Conclusion Optimal treatment result was gained through Straumman implants applied in the maxillarv anterior region with satifactory aesthetic expectation.Its further use was predictable and advisable.

Objective To explore the application value of magnetic resonance molecular functional imaging diffusion weighted imaging(DWI) in the identification of pancreatic carcinoma and mass-type pancreatitis of animal model.Methods Each 8 cases of laboratory pancreatic head transplantation tumor model,chronic mass-type pancreatitis model and normal rabbits were selected and performed the MR DWI molecular functional imaging,the b values were 333,667,1 000 s/mm2 respectively.The apparent diffusion coefficients(ADC) of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values were observed.Then the change situation of ADC values of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values and difference of ADC(DADC) was analyzed.Moreover the differences in molecular diffusion,tissue perfusion among various groups were observed.Results Throughout the study period,the mortality rate of pancreatic head transplantation tumor model was 50%;the mass-type pancreatitis model and 8 normal rabbits were normally survival.The ADC value of pancreatic carcinoma under the same b value was significantly lower than that of chronic inflammation and normal pancreas area.The ADC value in each group was decreased with the increase of b value,and there was significant difference in ADC value when the b value was 333 s/mm2(F=6.662,P=0.014),in the pairwise comparison among groups,the difference between pancreatic cancer and pancreatitis (t=6.773,P=0.003) and between pancreatic cancer and normal pancreas(t=5.883,P=0.016) had statistical significance (P<0.05).The b value was increased,DADC was smaller,the difference change of DADC between pancreatic cancer area and chronic pancreatitis mass area,between pancreatic cancer area and normal pancreatic head area had statistical significance (P<0.05).Conclusion Rationally selecting the molecular functional imaging DWI technology of b value can better distinguish pancreatic cancer from mass-type pancreatitis,which may be promoted and applied in the evaluation of animal pancreatic head cancer model.