| Background and objective:Immediate implant placement refers to the insertion of implant immediately at the time of tooth extraction,which can reduce treatment times and surgical interventions,and possibly prevent the shrinkage of buccal contour.However,immediate implant placement is identified as a complex procedure,especially for the wide or multiple sockets of posterior teeth,and the treatment planning should be carefully considered.Although some researches indicated that immediate implant placement in posterior sockets with chronic infection and bone defects showed high survival rates,the current evidence is not sufficient to draw conclusions,and more clinical studies and longer follow-up are needed to verify the feasibility of immediate implant placement in this setting.This paper designs a retrospective cohort clinical study based on imaging analysis of immediate implant placement into posterior sockets with or without bone defect,aiming to evaluate the therapeutic effect of immediate implant placement into such teeth,analyze the factors affecting the decision of immediate implant placement,and explore standardized and reliable clinical procedures.Methods:From January 2018 to January 2023,patients who treated at the Department of Oral Implantology,Jilin University Hospital of Stomatology for immediate implant restoration due to failure to retain posterior teeth,and were selected and screened according to the inclusion and exclusion criteria.All patients were divided into two groups according to the presence or absence of bone defect: a dehiscence group with the alveolar crest of buccal or oral side was ≥3 mm from the gingival margin,and a non-dehiscence group with the alveolar crest of buccal or oral side was <3 mm from the gingival margin.All patients were taken CBCT at four time intervals: pre-operation(T0),immediately after surgery(T1),6 months after surgery(T2),and 1 year after functional loading(T3).The measurements included: horizontal buccal bone height(HBT)at the implant platform,3 mm below the platform,5 mm below the platform and horizontal oral bone height(HOT);vertical buccal bone height(VBH);vertical oral oral height(VOH);bone resorption in the vertical and horizontal directions on the buccal and oral side of the implant;marginal bone level(MBL)before and after functional loading;the survival rate of implants;and the incidence of biological complications of implants.Results:A total of 27 patients were included according to the inclusion and exclusion criteria.In the dehiscence group,12 patients(5 males,7 females)and 13 implants were included,with an average age of 59.08 ± 11.26 years.In the non-dehiscence group,15patients(6 males,9 females)and 16 implants were included,with an average age of49.69 ± 15.33 years.1.The survival rates of implants in the dehiscence and non-dehiscence groups were100% and 94.12%,respectively,with no significant differences(P>0.05).2.After implant surgery and during the follow-up period,the incidence of biological complications of implants in the dehiscence and non-dehiscence groups were7.69% and 6.54%,respectively,with no significant difference(P>0.05).3.The buccal and oral bone absorption at 6 months after surgery: in the dehiscence groups,HBT-0,HBT-3 and HBT-5 were 1.65 ± 0.99 mm,2.46 ± 1.01 mm and 2.88 ±1.12 mm.HOT-0,HOT-3 and HOT-5 were 1.35 ± 0.96 mm,2.73 ± 0.94 mm and 3.38 ±1.09 mm.VBH and VOH were 1.14 ± 0.85 mm and 0.86 ± 1.13 mm.In the non-dehiscence groups,HBT-0,HBT-3 and HBT-5 were 1.73 ± 1.19 mm,3.23 ± 1.51 mm and 4.06 ± 2.17 mm.HOT-0,HOT-3 and HOT-5 were 2.36 ± 1.65 mm,3.29 ± 1.38 mm and 3.79 ± 1.56 mm.VBH and VOH were 1.09 ± 0.97 mm and 0.89 ± 0.93 mm.There was no significant difference between the two groups(P>0.05).4.The buccal and oral bone absorption at 6 months after surgery: in the dehiscence groups,the bone resorption of HBT-0,HBT-3 and HBT-5 were 0.64 ± 0.38 mm,0.43 ±0.33 mm and 0.35 ± 0.35 mm.The bone resorption of HOT-0,HOT-3 and HOT-5 were0.43 ± 0.47 mm,0.25 ± 0.23 mm and 0.18 ± 0.24 mm.The bone resorption of VBH and VOH were 0.36 ± 0.36 mm and 0.41 ± 0.29 mm.In the non-dehiscence groups,the bone resorption of HBT-0,HBT-3 and HBT-5 were 0.90 ± 1.12 mm,0.31 ± 0.53 mm and 0.24± 0.51 mm.The bone resorption of HOT-0,HOT-3 and HOT-5 were 0.50 ± 0.54 mm,0.17 ± 0.23 mm and 0.21 ± 0.42 mm.The bone resorption of VBH and VOH were 0.58± 0.65 mm and 0.38 ± 0.55 mm.There was no significant difference between the two groups(P>0.05).5.The buccal and oral bone resorption within 1 year of functional loading: in the dehiscence groups,the bone resorption of HBT-0,HBT-3 and HBT-5 were 0.44 ± 0.46 mm,0.33 ± 0.40 mm and 0.21 ± 0.33 mm.The bone resorption of HOT-0,HOT-3 and HOT-5 were 0.12 ± 0.16 mm,0.15 ± 0.17 mm and 0.16 ± 0.24 mm.The bone resorption of VBH and VOH were 0.66 ± 1.31 mm and 0.18 ± 0.38 mm.In the non-dehiscence groups,the bone resorption of HBT-0,HBT-3 and HBT-5 were 0.29 ± 0.35 mm,0.33 ±0.46 mm and 0.19 ± 0.28 mm.The bone resorption of HOT-0,HOT-3 and HOT-5 were0.22 ± 0.28 mm,0.08 ± 0.09 mm and 0.08 ± 0.16 mm.The bone resorption of VBH and VOH were 0.46 ± 1.07 mm and 0.08 ± 0.18 mm.There was no significant difference between the two groups(P>0.05).6.The changes in marginal bone level within 1 year of functional loading: in the dehiscence group,-0.16 ± 0.13 mm and-0.19 ± 0.11 mm for the mesial and distal middle marginal bone level changes.In the non-dehiscence group,-0.12 ± 0.08 mm and-0.14 ±0.09 mm for the mesial and distal middle marginal bone level changes.There was no significant difference between the two groups(P>0.05).Conclusions:1.For posterior extraction sockets with bone defects,immediate implant placement is a viable option if the defect is limited to the buccal or oral bone wall and the remaining alveolar bone volume can provide initial stability and blood supply for the implant.2.The peri-implant bone height and bone width obtained after simultaneous bone augmentation with immediate implant placement in posterior extraction sockets with bone defects were similar to those in the group without bone defects.3.After immediate implant surgery,the degree of bone remodeling during 6months and 1 year of functional loading in the dehiscence and non-dehiscence groups was basically similar,and there was no significant difference between them. |
