Effects Of Mandibular Overdenture Attachment Type And Number Of Dental Implants On Peri-implant Health: Network Meta-analysis

BackgroudEdentulous jaw is an oral condition in some middle-aged and elderly patients.Conventional complete denture has long been considered as one of the treatment options for restoring aesthetic and function of edentulous patients in the past.It has the advantages of being,the cheapest treatment for replacing the entire teeth in upper or lower jaw,the shortest treatment time from start to finish,and the aesthetically acceptable treatment regime.However,with the further absorption of alveolar ridge,conventional removable dentures have its inherent disadvantages,especially in patients with alveolar ridge atrophy,such as low retention,lack of stability,low chewing efficiency,about which patients complained.The development and progress of the implant overdenture can not only solve the problems of retention and stability,but also meet the needs of patients who can remove,wear and clean themselves.While,in the edentulous mandible,the number of implants supporting the overdenture varies from one to four,the attachment system also has a variety of options.To date,a hot debate exists regarding the effect of the different number of dental implants along with different anchorage on the peri-implant health,and still lacks of comprehensive evidence-based medical evidence.BackgroudThrough systematic review and network meta-analysis,the effects of mandibular overdenture attachment system along with different number of dental implants on peri-implant health were explored,so as to provide a certain reference foundation for the application of implant overdenture in the treatment of edentulous mandible and possible clinical problems.Materials and Methods1.Search strategy.Electronic databases(Medline/Pub Med,Embase,Cochrane Library and Scopus)were systematically searched combined with manual search through journals related to dental implants and prostheses.2.Eligibility CriteriaInclusion criteria:(1)Randomized controlled trials and Observational studies(prospective studies and retrospective studies);(2)Studies compared different overdenture attachment systems along with different number of dental implants with a minimum follow-up ≥12 months(4)Full-text articles published in English and reported at least one of the outcomes of interest(marginal bone loss,peri-implant parameters(bleeding index,plaque index,probing depth,gingiva index),and implant survival.Exclusion criteria:(1)Single cohort studies,crossover trials,case report,literature review or conference abstracts;(2)Studies involving mini-implant;(3)Studies included patients receiving implant overdenture in maxilla or partially edentulous mandible;(4)Unavailable English full-texts or lack of the information about main outcomes of interest.(5)study with <5 patients in each group.3.Data ExtractionThe following data were extracted: publication information,study type,sample size,average age,the number of implants supporting mandibular overdentures,attachment type,loading protocol,outcomes of interest,etc.4.Methodological quality appraisalQuality assessment and bias were assessed by combining the proposed criteria of the Meta-Analysis of Observational Studies in Epidemiology(MOOSE)statement,the Strengthening the Reporting of Observational Studies in Epidemiology(STROBE)statement and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)statement.5.Data synthesisTraditional pairwise meta-analyses of different attachment system along with different dental implants were executed using Comprehensive Meta-Analysis Software(Biostat Inc,Englewood,NJ).The Bayesian network meta-analysis(NMA)was performed using Ge MTC package supported by R.The weighted mean difference(WMD)accompanied by 95% credible intervals(Cr I)was estimated.ResultsTwenty-eight studies with a total of 1166 participants and 2666 dental implants were included.With the exception of 4Bar and 4Telescopic,which showed a statistically less MBL compared to 2LOCATOR,all other interventions showed insignificant difference concerning MBL(P>0.05).The difference in peri-implant probing depth was not statistically significant when comparing different groups.The pooled implant survival rates of different interventions ranged between 88.9%,and 100%.The rank probability test showed that 4Bar and 4Telescopic had the least MBL,2Magnet had the highest PI and BI,whereas 4LOCATOR showed the least PPD.ConclusionThe present evidence revealed that different number of dental implants supported mandibular overdenture with various anchorage systems had a similar effect on the peri-implants health.Four implants+ Bar or Telescopic attachments are associated with the least MBL whereas 4LOCATOR had the least PPD.