Systematic Review| Volume 121, ISSUE 1, P41-51, January 2019

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Should the restoration of adjacent implants be splinted or nonsplinted? A systematic review and meta-analysis


      Statement of problem

      The decision to splint or to restore independently generally occurs during the planning stage, when the advantages and disadvantages of each clinical situation are considered based on the proposed treatment. However, clinical evidence to help clinicians make this decision is lacking.


      The purpose of this systematic review and meta-analysis was to assess the marginal bone loss, implant survival rate, and prosthetic complications of splinted and nonsplinted implant restorations.

      Material and methods

      This study was designed according to the Cochrane criteria for elaborating a systematic review and meta-analysis and adopted the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Also, this review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017080162). An electronic search in the PubMed/MEDLINE, Cochrane Library, and Scopus databases was conducted up to November 2017. A specific clinical question was structured according to the population, intervention, comparison, outcome (PICO) approach. The addressed focused question was “Should the restoration of adjacent implants be splinted or nonsplinted?” The meta-analysis was based on the Mantel-Haenszel and inverse variance methods to assess the marginal bone loss, implant survival, and prosthetic complications of splinted and nonsplinted implant restorations.


      Nineteen studies were selected for qualitative and quantitative analyses. A total of 4215 implants were placed in 2185 patients (splinted, 2768; nonsplinted, 1447); the mean follow-up was 87.8 months (range=12-264 months). Quantitative analysis found no significant differences between splinted and nonsplinted restorations for marginal bone loss. The assessed studies reported that 75 implants failed (3.4%), of which 24 were splinted (99.1% of survival rate) and 51 were nonsplinted (96.5% of survival rate). Quantitative analysis of all studies showed statistically significant higher survival rates for splinted restorations than for nonsplinted restorations. Ceramic chipping, screw loosening, abutment screw breakage, and soft tissue inflammation were reported in the selected studies. The quantitative analysis found no statistically significant difference in the prosthetic complications of splinted and nonsplinted restorations.


      Within the limitations of this systematic review and meta-analysis, it was concluded that there was no difference in the marginal bone loss and prosthetic complications of splinted and nonsplinted implant restorations; this is especially true for restorations in the posterior region. However, splinted restorations were associated with decreased implant failure.
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        • Hasegawa T.
        • Kawabata S.
        • Takeda D.
        • Iwata E.
        • Saito I.
        • Arimoto S.
        • et al.
        Survival of Brånemark System Mk III implants and analysis of risk factors associated with implant failure.
        Int J Oral Maxillofac Surg. 2017; 46: 267-273
        • Lemos C.A.
        • de Souza Batista V.E.
        • Almeida D.A.
        • Santiago Júnior J.F.
        • Verri F.R.
        • Pellizzer E.P.
        Evaluation of cement-retained versus screw-retained implant-supported restorations for marginal bone loss: a systematic review and meta-analysis.
        J Prosthet Dent. 2016; 115: 419-427
        • Verri F.R.
        • Batista V.E.
        • Santiago Jr., J.F.
        • Almeida D.A.
        • Pellizzer E.P.
        Effect of crown-to-implant ratio on peri-implant stress: a finite element analysis.
        Mater Sci Eng C Mater Biol Appl. 2014; 45: 234-240
        • Vigolo P.
        • Mutinelli S.
        • Zaccaria M.
        • Stellini E.
        Clinical evaluation of marginal bone level change around multiple adjacent implants restored with splinted and nonsplinted restorations: a 10-year randomized controlled trial.
        Int J Oral Maxillofac Implants. 2015; 30: 411-418
        • Clelland N.
        • Chaudhry J.
        • Rashid R.G.
        • McGlumphy E.
        Split-mouth comparison of splinted and nonsplinted prostheses on short implants: 3-year results.
        Int J Oral Maxillofac Implants. 2016; 31: 1135-1141
        • Pellizzer E.
        • Santiago Jr., J.
        • Villa L.
        • de Souza Batista V.
        • de Mello C.
        • de Faria Almeida D.
        • et al.
        Photoelastic stress analysis of splinted and unitary implant-supported prostheses.
        Appl Phys B. 2014; 117: 235-244
        • Bergkvist G.
        • Simonsson K.
        • Rydberg K.
        • Johansson F.
        • Derand T.
        A finite element analysis of stress distribution in bone tissue surrounding uncoupled or splinted dental implants.
        Clin Implant Dent Relat Res. 2008; 10: 40-46
        • de Souza Batista V.E.
        • Verri F.R.
        • Almeida D.A.
        • Santiago Junior J.F.
        • Lemos C.A.
        • Pellizzer E.P.
        Evaluation of the effect of an offset implant configuration in the posterior maxilla with external hexagon implant platform: a 3-dimensional finite element analysis.
        J Prosthet Dent. 2017; 118: 363-371
        • Solnit G.S.
        • Schneider R.L.
        An alternative to splinting multiple implants: use of the ITI system.
        J Prosthodont. 1998; 7: 114-119
        • Vázquez Álvarez R.
        • Pérez Sayáns M.
        • Gayoso Diz P.
        • García García A.
        Factors affecting peri-implant bone loss: a post-five-year retrospective study.
        Clin Oral Implants Res. 2015; 26: 1006-1014
      1. Higgins JPT, Green S, eds. Cochrane handbook for systematic reviews of interventions version 5.1.0 [updated March 2011]. The Cochrane Collaboration; 2011. Available from

        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        PRISMA Group preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        Int J Surg. 2010; 8: 336-341
        • Lemos C.A.
        • Verri F.R.
        • Batista V.E.
        • Júnior J.F.
        • Mello C.C.
        • Pellizzer E.P.
        Complete overdentures retained by mini implants: a systematic review.
        J Dent. 2017; 57: 4-13
        • Egger M.
        • Smith G.D.
        • Altman D.G.
        Systematic reviews in health care: meta-analysis in context.
        2nd ed. BMJ Books, London2003: 23-42
        • Chrcanovic B.R.
        • Albrektsson T.
        • Wennerberg A.
        Turned versus anodised dental implants: a meta-analysis.
        J Oral Rehabil. 2016; 43: 716-728
        • Duval S.
        • Tweedie R.
        Trim and fill: a simple funnel plot-based method of testing and adjusting for publication bias in meta-analysis.
        Biometrics. 2000; 56: 455-463
        • Santiago Jr., J.F.
        • Batista V.E.
        • Verri F.R.
        • Honório H.M.
        • de Mello C.C.
        • Almeida D.A.
        • et al.
        Platform-switching implants and bone preservation: a systematic review and meta- analysis.
        Int J Oral Maxillofac Surg. 2016; 45: 332-345
        • Landis J.R.
        • Koch G.G.
        The measurement of observer agreement for categorical data.
        Biometrics. 1977; 33: 159-174
        • Maló P.
        • Friberg B.
        • Polizzi G.
        • Gualini F.
        • Vighagen T.
        • Rangert B.
        Immediate and early function of Brånemark System implants placed in the esthetic zone: a 1-year prospective clinical multicenter study.
        Clin Implant Dent Relat Res. 2003; 1: 37-46
        • Rocci A.
        • Martignoni M.
        • Gottlow J.
        Immediate loading in the maxilla using flapless surgery, implants placed in predetermined positions, and prefabricated provisional restorations: a retrospective 3-year clinical study.
        Clin Implant Dent Relat Res. 2003; 1: 29-36
        • Rokni S.
        • Todescan R.
        • Watson P.
        • Pharoah M.
        • Adegbembo A.O.
        • Deporter D.
        An assessment of crown-to-root ratios with short sintered porous-surfaced implants supporting prostheses in partially edentulous patients.
        Int J Oral Maxillofac Implants. 2005; 20: 69-76
        • Bilhan H.
        • Mumcu E.
        • Arat S.
        The role of timing of loading on later marginal bone loss around dental implants: a retrospective clinical study.
        J Oral Implantol. 2010; 36: 363-376
        • Sohn D.S.
        • Kim W.S.
        • Lee W.H.
        • Jung H.S.
        • Shin I.H.
        A retrospective study of sintered porous-surfaced dental implants in restoring the edentulous posterior mandible: up to 9 years of functioning.
        Implant Dent. 2010; 19: 409-418
        • Vigolo P.
        • Zaccaria M.
        Clinical evaluation of marginal bone level change of multiple adjacent implants restored with splinted and nonsplinted restorations: a 5-year prospective study.
        Int J Oral Maxillofac Implants. 2010; 25: 1189-1194
        • Perelli M.
        • Abundo R.
        • Corrente G.
        • Saccone C.
        Short (5 and 7 mm long) porous implant in the posterior atrophic mandible: a 5-year report of a prospective study.
        Eur J Oral Implantol. 2011; 4: 363-368
        • Perelli M.
        • Abundo R.
        • Corrente G.
        • Saccone C.
        Short (5 and 7 mm long) porous implants in the posterior atrophic maxilla: a 5-year report of a prospective single-cohort study.
        Eur J Oral Implantol. 2012; 5: 265-272
        • Rodrigo D.
        • Cabello G.
        • Herrero M.
        • Gonzalez D.
        • Herrero F.
        • Aracil L.
        • et al.
        Retrospective multicenter study of 230 6-mm SLA-surfaced implants with 1- to 6-year follow-up.
        Int J Oral Maxillofac Implants. 2013; 28: 1331-1337
        • Sivolella S.
        • Stellini E.
        • Testori T.
        • Di Fiore A.
        • Berengo M.
        • Lops D.
        Splinted and unsplinted short implants in mandibles: a retrospective evaluation with 5 to 16 years of follow-up.
        J Periodontol. 2013; 84: 502-512
        • Vanlıoğlu B.
        • Özkan Y.
        • Kulak-Özkan Y.
        Retrospective analysis of prosthetic complications of implant-supported fixed partial dentures after an observation period of 5 to 10 years.
        Int J Oral Maxillofac Implants. 2013; 28: 1300-1304
        • Wagenberg B.D.
        • Froum S.J.
        • Eckert S.E.
        Long-term bone stability assessment around 1,187 immediately placed implants with 1- to 22-year follow-up.
        Int J Oral Maxillofac Implants. 2013; 28: 605-612
        • Mendonça J.A.
        • Francischone C.E.
        • Senna P.M.
        • Matos de Oliveira A.E.
        • Sotto-Maior B.S.
        A retrospective evaluation of the survival rates of splinted and non-splinted short dental implants in posterior partially edentulous jaws.
        J Periodontol. 2014; 85: 787-794
        • Sohn D.S.
        • Lee J.M.
        • Park I.S.
        • Jung H.S.
        • Park D.Y.
        • Shin I.H.
        Retrospective study of sintered porous-surfaced dental implants placed in the augmented sinus.
        Int J Periodontics Restorative Dent. 2014; 34: 565-571
        • Wagenberg B.
        • Froum S.J.
        Long-term bone stability around 312 rough-surfaced immediately placed implants with 2-12-year follow-up.
        Clin Implant Dent Relat Res. 2015; 17: 658-666
        • Ghaleh Golab K.
        • Balouch A.
        • Mirtorabi S.
        One-year multicenter prospective evaluation of survival rates and bone resorption in one-piece implants.
        Clin Implant Dent Relat Res. 2016; 18: 392-400
        • Wang J.H.
        • Judge R.
        • Bailey D.
        Five-year retrospective assay of implant treatments and complications in private practice: restorative treatment profiles of single and short-span implant-supported fixed prostheses.
        Int J Prosthodont. 2016; 29: 372-380
        • Shi J.Y.
        • Xu F.Y.
        • Zhuang L.F.
        • Gu Y.X.
        • Qiao S.C.
        • Lai H.C.
        Long-term outcomes of narrow diameter implants in posterior jaws: a retrospective study with at least 8-year follow-up.
        Clin Oral Implants Res. 2018; 29: 76-81
        • Al Amri M.D.
        • Kellesarian S.V.
        Crestal bone loss around adjacent dental implants restored with splinted and nonsplinted fixed restorations: a systematic literature review.
        J Prosthodont. 2017; 26: 495-501
        • Schuldt Filho G.
        • Dalago H.R.
        • Oliveira de Souza J.G.
        • Stanley K.
        • Jovanovic S.
        • Bianchini M.A.
        Prevalence of peri-implantitis in patients with implant-supported fixed prostheses.
        Quintessence Int (Berl). 2014; 45: 861-868
        • Derks J.
        • Schaller D.
        • Håkansson J.
        • Wennström J.L.
        • Tomasi C.
        • Berglundh T.
        Peri-implantitis—onset and pattern of progression.
        J Clin Periodontol. 2016; 43: 383-388
        • Gracis S.
        • Michalakis K.
        • Vigolo P.
        Vult von Steyern P, Zwahlen M, Sailer I. Internal vs. external connections for abutments/reconstructions: a systematic review.
        Clin Oral Implants Res. 2012; 6: 202-216
        • Goiato M.C.
        • Pellizzer E.P.
        • da Silva E.V.
        Bonatto Lda R, dos Santos DM. Is the internal connection more efficient than external connection in mechanical, biological, and esthetical point of views? A systematic review.
        Oral Maxillofac Surg. 2015; 19: 229-242
        • Lemos C.A.A.
        • Verri F.R.
        • Santiago Jr., J.F.
        • Almeida D.A.F.
        • Batista V.E.S.
        • Noritomi P.Y.
        • et al.
        Retention system and splinting on Morse taper implants in the posterior maxilla by 3D finite element analysis.
        Braz Dent J. 2018; 29: 30-35
        • Pellizzer E.P.
        • de Mello C.C.
        • Santiago Jr., J.F.
        • de Souza Batista V.E.
        • de Faria Almeida D.A.
        • Verri F.R.
        Analysis of the biomechanical behavior of short implants: the photo-elasticity method.
        Mater Sci Eng C Mater Biol Appl. 2015; 55: 187-192