| Part 1[Backgroud]Dental implants have been considered as a successful treatment for the rehabilitation of edentulous jaws because of its excellent survival rates and clinical outcomes.In the posterior maxilla,due to missing teeth and the physiological gasification of the maxillary sinus,the length of the alveolar crest to the maxillary sinus floor is limited and often unable to be implanted with a conventional implant longer than 10 mm.In order to solve this problem,many surgical procedures for bone regeneration have been introduced into oral implantology,such as distraction osteogenesis,autologous bone grafting,guided bone regeneration,etc.However,these operations have relatively large surgical trauma,complex operation procedure and unpredictable clinical outcomes.Maxillary sinus floor lift as a way to effectively increase the height of the alveolar ridge in the posterior maxillary region,it has a relatively simpler surgical operation procedure and a high success rate,which has been widely used in clinic.With the development of implant design concepts and manufacturing processes,short dental implants are gradually being used in clinical practice.In atrophic posterior mandibular,short implants can avoid additional bone regeneration surgery.In atrophic posterior maxilla,by placing short implants,doctors can avoid maxillary sinus floor augmentation,thus avoiding complications such as perforation of the maxillary sinus membrane,intraoperative bleeding.Short implants treatment is a relatively minimally invasive dental implant surgery and can improve patient satisfaction with treatment.At present,the complicated maxillary sinus floor augmentation is widely used in clinical practice,and the application of short implants in posterior maxilla in still lacks sufficient evidence-based medical support.[Objective]In this study,a systematic review and meta-analysis was conducted to compare the clinical outcomes of maxillary sinus floor augmentation with conventional implants and direct implantation of short implants for rehabilitation of atrophic posterior maxilla in a 3-year follow-up period.[Methods]A systematic electronic research was performed in PubMed,Embase and Cochrane Library until August 2018 to identify articles reporting on short implants in contradistinction to standard implants with maxillary sinus floor agumentation.An additional hand search of the related reviews and the references of included articles was conducted to complement the electronic search.The search results were imported into the Endnote software for the removal of the duplicated literature and preliminary screening based on the titles and abstracts of papers.Two reviewers then independently performed the study selection process by screening the full text of remaining studies after the former selection based on the inclusion and exclusion criteria.Then two independent researchers conducted data extraction on the included literature based on a pre-established data extraction table and then assessed the risk of bias of studies,and finally conducted data analysis.The primary outcome of this study was survival rates of implants,and the secondary outcomes were marginal bone loss,complications,and patient satisfaction.[Results]Through screening of 642 titles and abstracts,six randomized controlled trials comparing short implants and conventional implants after maxillary sinus floor augmentation with 3-year follow-up met the inclusion criteria.A total of 203 short implants with lengths ?6mm and 214 standard implants with lengths ?10mm were placed based on the included studies.Generally,all trials included demonstrated a low risk of bias in the majority of domains.There was no significant difference in implant survival rates between the short implants and the conventional implants with maxillary sinus floor augmentation(RR:0.98;95%Cl:[0.95,1.02];p=0.38).In terms of marginal bone loss,the data synthesis results showed that short implants were more favorable(MD=-0.19;95%CI:[-0.33,-0.05];p=0.007).Intraoperative and postoperative complications in the maxillary sinus augmentation group occurred more than in the short implants group.The incidence of peri-implant mucositis was not statistically different between the two groups(RR=0.94;95%CI:[0.15,5.85];p=0.95).The incidence of peri-implantitis was very low with a total of 2 losses of implants,all the two events happened in the short-implant group in the same literature.Short implants showed more mechanical complications than the conventional implants group(RR=2.83;95%CI:[1.18,6.76];p=0.02).There was no significant difference between the two groups in prosthesis complications(RR=0.92;95%CI:[0.21,4.01];p=0.91).Only 2 trials reported patient satisfaction at the 3-year follow-up.In one of the 2 studies,the results of the satisfaction survey on functional and aesthetic effects were not statistically different;another study showed statistical differences only in treatment costs,the patients in the short implants group were more satisfied.In the other 7 aspects,the statistical results of the 2 groups were not statistically different.[Conclusion]At 3 years of follow-up,short implants have similar clinical survival rates as conventional implants,and are superior to conventional implants after sinus floor agumentation in maintaining bone level around the implant.The intraoperative and postoperative complications of sinus floor augmentation were significantly higher than short implant placement.Therefore,the short implants can be applied to the rehabilitation of the alveolar ridge in the maxillary posterior region,avoiding the complicated surgical operation procedure and the severer postoperative response.Short implants treatment also saves part of the patient's treatment costs.However,short implants have also shown more mechanical complications,especially the looseness of the abutment screws.More research on short implant abutment joint designs and machining is needed in the future.Of course,more high-quality,long-term follow-up randomized controlled trials to assess the long-term clinical outcomes of short implants are also needed.Part 2[Backgroud]Dental implants have been considered as a successful treatment for the rehabilitation of edentulous jaws because of its excellent survival rates and clinical outcomes.In the posterior region of jaws,the functional reconstruction of the alveolar ridge due to periodontitis and missing teeth lead to the distance between the alveolar crest and the maxillary sinus floor is often not implanted in an implant longer than 8 mm.So does the distance between alveolar crest of the mandibular to the neural tubes.In order to solve this problem,many surgical procedures for bone regeneration have been introduced into oral implantology,such as distraction osteogenesis,autologous bone grafting,guided bone regeneration,inferior alveolar nerve transposition,etc.However,these operations have relatively large surgical trauma,complex operation procedure and unpredictable clinical outcomes.Maxillary sinus floor lift as a way to effectively increase the height of the alveolar ridge in the posterior maxillary region,it has a relatively simpler surgical operation procedure and a high success rate.With the development of implant design concepts and manufacturing processes,short implants are gradually being used in clinical practice.In atrophic posterior mandibular,short implants can avoid additional bone regeneration surgery.In atrophic posterior maxilla,by placing short implants,doctors can avoid maxillary sinus floor augmentation,thus avoiding complications such as perforation of the maxillary sinus membrane,intraoperative bleeding.Short implants treatment is a relatively minimally invasive dental implant surgery and can improve patient satisfaction with treatment.At present,the long-term follow-up of short implants is still relatively rare,and the long-term success rate of short-plant implant restoration is still unclear.The impact of different crown/implant ratios and different implant systems on the long-term clinical outcomes of short implants is still controversial.[Objective]A retrospective study was performed to analyze the 5-year clinical outcome of short implants in the upper and lower jaw posterior region and to compare the 5-year clinical outcomes between different implant systems,the upper and lower jaws,and different crown/implant ratios.[Methods]A retrospective study of 81 patients with atrophic lower alveolar posterior alveolar ridge implants in the Department of Oral Implantology,Nanjing Stomatological Hospital,Medical School of Nanjing University from February 2013 to August 2013,implanted with 134 short implants(?8mm).47 short implants were implanted in posterior maxilla and the other 87 short implants were implanted in posterior mandibular.Among them,75 were Straumann implant system,32 were Dentium implant system and 27 were Bicon implant system.Secondary surgery was performed 4 to 6 months after surgery and provisional prostheses was retained 2 to 4 weeks later.After 5 years of follow-up,the outcomes of different implant systems,different crown-to-root ratios of implant survival rates,peri-implant marginal bone level changes were statistically analyzed.[Results]The cumulative retention rate of implants was 95.52%.There was no statistical difference in implant retention rate between different implant systems,between upper and lower jaws,and between different implants.(P>0.05).After 5-year loading period,the average peri-implant marginal bone level change was 0.41±0.09 mm.There was no statistical difference in the change of peri-implant marginal bone level between different implant systems,between the upper and lower jaws,and between different crown/implant ratios(P>0.05).[Conclusion]Short implants have reliable 5-year clinical outcomes as a treatment of rehabitation of the atrophy of the alveolar ridge in the posterior region with a high 5-year implant survival rate and a relatively stable peri-implant marginal bone level.There were no significant differences in the 5-year clinical outcomes of short implants between different implant systems,upper and lower jaws,and different crown/implant ratios.More large-scale long-term follow-up studies will be needed in the future to better understand if short implants could be effective in the long-term. |
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