Clinical effects of immediate implantation and delayed implantation in the posterior mandibular region

XI Yun-hao; FENG Yan; WU Pin-lin; ZHANG Xin; GENG Xiao-qing; LI Xiao-fei; LI Chang-shun

doi:10.19538/j.kq.2025.01.007

Abstract：Objective To study the clinical effects of immediate implantation and delayed implantation in the posterior mandibular region.Methods A total of 60 patients(60 dental implants)who underwent implant restoration in the posterior mandibular region at the Department of Stomatol-ogy,Affiliated Hospital of Integrated Traditional Chinese and Western Medicine,Nanjing University of Chinese Medicine,and the Affiliated Stomatological Hospital of Xuzhou Medical University between March 2020 and March 2022 were selected.According to the timing of im-plant placement,the patients were divided into immediate group(30 cases,immediate implantation)and delayed group(30 cases,delayed implantation).Totally 30 dental implants were used in each group.The two groups were compared in terms of treatment cycle,health degree of periodontal tissues[probing depth(PD),modified plaque index(mPLI)and modified bleeding index(mBI)]at 1 month,3 months and 6 months after crown restoration,mesial and distal marginal bone resorption and buccal bone resorption at 3 months,6 months and 12 months after implant placement,alveolar ridge resorption at 12 months after implant placement,implant stability quotient(ISQ)after surgery and before restoration,the occurrence of complications within 12 months after implant placement,and the success rate of implantation.Results Treatment cycle of the immediate group[(6.13±0.35)months]was significantly shorter than that of the delayed group[(9.13±0.35)months](t=33.605,P＜0.001).There were no statistically significant differences in PD,mPLI,or mBI between the two groups at 1 month,3 months and 6 months after crown restoration(all P＞0.05).At 3 months,6 months and 12 months after implant placement,implant marginal bone resorption was observed in both groups.There were no statistically significant differences in mesial and distal marginal bone resorption,buccal bone plate absorption,buccal bone plate absorption rate,buccal bone volume absorption,or buccal bone volume absorption rate between the two groups(all P＞0.05).At 12 months after implant placement,there were decreases in alveolar ridge width and height at each site.There was a statistically significant difference in absorption of alveolar ridge width at site 1(shoulder of the im-plant)between the immediate group and the delayed group(Z=2.167,P=0.030);however,there was no statistically sig-nificant differences in alveolar ridge width and height at the other sites(all P＞0.05).There were no statistically signifi-cant differences in ISQ after surgery and before restoration or in wound infection rate within 12 months after implant placement between the two groups(both P＞0.05).The incidence rate of peri-implantitis in the immediate group within 12 months after implant placement[7 cases(23.33％)]was significantly higher than that in the delayed group[0 case(0％)](x2=5.822,P=0.016).The success rates of implantation in both groups within 12 months after implant place-ment reached 100％.Conclusion Immediate implantation and delayed implantation in the posterior mandibular region both can achieve good clinical effects,and the former can effectively shorten the treatment cycle.However,there is a higher risk of peri-implantitis after immediate implantation.Therefore,susceptible factors should be controlled actively,and targeted prevention and treatment measures should be taken.