Clinical Study On Different Number Of Implant Supported Overdentures In Mandible

Objective: With the increase of population aging in China,the proportion of edentulous patients is increasing.The maxillary complete denture is better than the mandibular denture in retention.The mandibular denture lacks stability and masticatory ability,which makes many patients unable to accept the mandibular complete denture repair [1].At present,the commonly used treatment is implant covered denture in the mandible to enhance the stability of the mandible denture and improve the comfort of the patients.Van steenberghe[2] et al published the first study on implant supported overdentures in 1987.Now,this treatment still accounts for a large proportion in the restoration of patients with dentition loss.For the patients with mandibular edentulous,some scholars have proposed the treatment plan of using two or four implants to support the mandibular overdenture,but at present,there is still controversy about which treatment plan is better.The purpose of this study is to compare the clinical effects of two and four implant supported mandibular overdentures,and to provide a reasonable basis and guidance for clinical implant supported dentures.Methods: From 2015 to 2018,20 patients with mandibular edentulous were randomly selected from XX Affiliated Stomatological Hospital,and the indications of implant surgery were met.Among them,there are 11 males and 9 females,the maximum age is 81,the minimum age is 61,and the average age is 73.Ten patients were treated with two implant supported and retained overdentures(group A),and 10 patients were treated with four implant supported overdentures(group B).All patients were fixed with implant ball cap attachment.Three months,six months and 12 months after implant repair were followed up for reexamination,and the implant retention rate,plaque index,bleeding,depth of exploration,marginal bone absorption and patient satisfaction between the two groups were compared.To evaluate whether there is statistical difference in the results of 2 and 4 implant supported overdentures.Results: The implant retention rate of both schemes was 100%.The plaque index was0.45 ± 0.09 in group A,0.47 ± 0.08 in group B,1.13 ± 0.12 in group A,1.17± 0.14 in group B,3.94 ± 0.79 in group A,3.86 ± 0.83 in group B,0.77 ±0.16 in group A and 0.69 ± 0.14 in group B.There was no significant difference between the two groups(P > 0.05).Conclusion: there is no significant difference in clinical and imaging results between two or four implants.Patients treated with two or four implant overdentures were satisfied with the results.For the sake of economic cost,two implant supported overdentures are recommended for patients with poor retention and stability.