Dental Implants With Immediate Loading Using Insertion Torque of 30 Ncm: A Systematic Review Dhelfeson Willya Douglas de Oliveira, DDS, MSc,* Frederico Santos Lages, DDS, MSc,* Leonardo Avellar Lanza, DDS, MSc,* Alex Martins Gomes, DDS, MSc,* Thallita Pereira Queiroz, DDS, MSc, PhD,† and Fernando de Oliveira Costa, DDS, MSc, PhD‡ D ental implants have become a treatment modality accepted by the scientific community for fully and partially edentulous patients.1 Indeed, the placement of implant- retained prostheses, particularly in the lower jaw, has significantly reduced the burden of edentulism.2 A 2-stage surgical technique is the conventional protocol and is the most efficient way to minimize the risk of implant failure.3–5 Traditional clinical guidelines recommend the placement of implants in healed sites, followed by 3 to 6 months of submucosal healing before functional loading.6 However, this 2-stage protocol can be physically and psychologically challenging for pa- tients, given the additional procedures associated with the second surgical phase, the long wait time for the resto- ration of function and aesthetics and inconvenience due to the multiple visits.7 Thus, a shorter approach with immediate loading has been developed to minimize these problems. With immediate loading, the pros- thesis is connected to the implants and is functionalwithin48hours after surgery.8,9 Studies report similar survival rates with both techniques7 and it can be applied to all designs of prostheses, despite the most common being the full-arch mandibular rehabilitation. The immediate loading of dental implants restored by a full-arch splintedfixedprosthesis has shownexcel- lent results. The fewer complications, the less morbidity associated interventions, and a simplified rehabilitation have con- tributed to the increase in the clinical use of this technique.10 Splintingmultiple implants together with a passive fitting prosthesis limits micromovements at the bone-implant interface. Stabilizing the implants upon placement and limiting micromove- ments to no more than 100 mm contrib- ute to successful osseointegration.11 Immediate implant loadingwith a provi- sional restoration has been proposed as a simpler, more predictable, less expen- sive, and less time-consumingmethod.12 Primary stability is one of the most important parameters to the immediate loading of an implant and is an important requirement for the long-term success of dental implants.4Other important factors include bone quality, macrointerlock, and microinterlock properties of the implant, bicortical initial stabilization, *PhD Student, Department of Periodontology, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil. †Professor, Implantology Post-Graduation Program, University Center of Araraquara, Araraquara, Brazil. ‡Professor, Department of Periodontology, School of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil. Reprint requests and correspondence to: Dhelfeson Willya Douglas de Oliveira, DDS, MSc, Postgraduate Program in Dentistry, Av. Pres. Antônio Carlos, 6627– Campus Pampulha–Sala 3312, Zip Code: 31.270-901, Belo Horizonte, MG, Brazil, Phone: +55 (31) 3409- 2470, E-mail: dhodonto@hotmail.com.br ISSN 1056-6163/16/02505-675 Implant Dentistry Volume 25 � Number 5 Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/ID.0000000000000444 Objective: This study aimed to perform a review of the literature regarding the survival rate of dental implants with immediate loading using insertion torque of 30 Ncm. Material and Methods: A sys- tematic review was performed based on the Preferred Reporting Items for Systematic Reviews and Meta- Analyses and the Cochrane Handbook for Systematic Reviews of Interventions (PROSPERO CRD42014015323). The search was performed in the PubMed, Web of Science, Cochrane Library electronic, OVID, and Scielo data- bases. Manual searches were also performed. The articles identified were assessed independently by 3 research- ers. Clinical trials reporting dental implants with immediate loading and 30 Ncm torque in patients ages 18 years or older were included. Results: The searches yielded 589 studies. Six studies were included in the systematic review. The survival rate of dental implants was 96.8%. Three studies showed a low potential risk of bias. Conclusion: There is not strong evidence that insertion torque of 30 Ncm is enough for implant survival in cases of immediate loading. (Implant Dent 2016;25:675–683) Key Words: dental prostheses, torsional forces, osseointegration, immediate loading DOUGLAS DE OLIVEIRA ET AL IMPLANT DENTISTRY / VOLUME 25, NUMBER 5 2016 675 Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. number and optimal distribution of im- plants and careful use of cantilevers.13 Different values of insertion torque are found in the literature, with 45 Ncm the most commonly used and consid- ered the safest and most therapeutic for immediate loading.14–18 However, lower torque values are related to pri- mary stability and have been increas- ingly used for immediate loading, despite the low degree of scientific evi- dence regarding such insertion torque values.19 Thus, the aim of the present studywas toperforma systematic review of the literature on the survival rates of dental implants with immediate loading using insertion torque of 30 Ncm. METHODS Protocol The present systematic review was performed based on the Preferred Re- porting Items for Systematic Reviews and Meta-Analyses statement guide- lines20 and the Cochrane Handbook for Systematic Reviews of Interven- tions.21 The protocol for this systematic review is registered on PROSPERO (CRD42014015323). Focus Question In cases of immediate loading, is insertion torque of 30 Ncm enough for the survival of dental implants? Search Strategy The studies included in this sys- tematic review were obtained through electronic searches of the PubMed/ MEDLINE, Web of Science, Cochrane Library electronic, OVID, and Scielo databases. The keywords used were searched in Health Sciences Descrip- tors (DeCs) and Medical Subject Head- ings (Mesh), and the following terms were used: (dental implant*) AND (immediate loading*) AND (torque*). A general search strategy was adapted to the characteristics of each database to identify studies of interest for this review. The databases were searched for articles and abstracts with no language restriction. A manual search of dental implant-related jour- nals was done. To identify the relevant journals to be hand searched, it was checked using the Cochrane Worldwide Handsearching Programme (http://us.cochrane.org/master-list). This hand searching included the following journals: British Journal of Oral and Maxillofacial Surgery; Clinical Implant Dentistry andRelatedResearch; Clinical Oral Implants Research; European Jour- nal of Oral Implantology; Implant Den- tistry; International Journal of Oral and Maxillofacial Implants; International Journal of Oral and Maxillofacial Surgery; International Journal of Peri- odontics and Restorative Dentistry; International Journal of Prosthodontics; Journal ofClinical Periodontology; Jour- nal of Dental Research; Journal of Oral Implantology; Journal of Oral and Max- illofacial Surgery; Journal of Periodon- tology; Journal of Prosthetic Dentistry. All the corresponding authors of the included clinical trials were con- tacted by e-mail to identify and obtain data from any unpublished or ongoing studies. The references contained in all studies and systematic reviews included were checked for additional trials. Screening and Selection Process For this systematic review, clini- cal trials (CTs) that met the inclusion criteria and dating from the inception of the respective databases through to September 2014 were selected. Inclusion was based on an analysis of the title and abstract of studies with regard to the eligibility criteria listed below. Type of study. Clinical trials (either randomized or not) of any design that evaluated the use of dental implant with immediate loading were considered. Participants. Patients were aged 18 years or older whowere having osseoin- tegrated root-form dental implants. Type of intervention. The interven- tions of interest were those involving dental implants with immediate load- ing. In this review, immediate loading was defined as an implant put into function within 48 hours after placement.8,9 Exclusion criteria. CTs not clearly meeting the inclusion criteria and those that did not report dental implants with exactly 30 Ncm insertion torque were excluded. Outcomes. The primary outcome in- cludes implant survival. Secondary outcomeswere prosthesis failure, radio- graphic marginal bone level changes, and postoperative complications. Review Method and Data Extraction The study selection process was performed by 3 reviewers (D.W.D.d.O., F.S.L., A.M.G.) in 2 phases. In the first phase, the 3 reviewers independently identified all relevant studies through electronic and other search methods based on the inclusion criteria applied to the titles and abstracts. For studies appearing tomeet the inclusion criteria or for which insufficient data were found in the title and abstract to make a clear decision, the full text was preselected. In the second phase, the preselected studies were analyzed by the same researchers to define whether the clinical trial met the inclusion criteria. When necessary, the authors of the clinical trials were con- tacted by e-mail to clarify issues related to the trials. Studies excluded in this or following stages were recorded along with the reasons for rejection. Clinical trials meeting the inclusion criteria were included in the final analysis and were submitted to data synthesis. Articles identified 2 or more times were consid- ered only once. The studies were analyzed and discussed by independent researchers who conducted the development of the systematic review. Disagreements were resolved by consensus among the 3 reviewers and a fourth reviewer (L.A.L.). This procedure was applied at all steps. The reviewers were trained for each database before the study. Data were recorded qualitatively to allow comparisons among the studies selected. Each researcher qualitatively assessed the studies using an evaluation form. Data were collected on the following items: author; year of publi- cation; country; study design; charac- teristics of participants; insertion torque; follow-up; prosthesis type; implant brand; and results regarding the dental implants. The survival rate was calculated for dental implants in- serted with insertion torque of 30 Ncm and immediate loading. Quality Assessment A methodological quality of the studies was assessed based on the 676 INSERTION TORQUE OF 30 NCM DOUGLAS DE OLIVEIRA ET AL Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. revised recommendations of the Con- solidated Standards of Reporting Trials statement.22 The criteria used are listed in Table 1. The risk of bias was esti- mated for each selected clinical trial based on the Cochrane Handbook for Systematic Reviews of Interventions21: low risk of bias (when all criteria were met); moderate risk of bias (when $1 criterion was partially met); and high risk of bias (when $1 criterion was not met). RESULTS After eliminating duplications, the electronic and hand searches yielded 589 potentially relevant references. In the first stage of study selection, 559 publications were excluded after the examination of the title and abstract. The full texts of the remaining 30 articles were read. Twenty articles were excluded in this second stage due to a lack of reporting the number of implants and descriptive statistics for dental implants with a insertion torque of 30 Ncm.15,17,18,23–39 Two manu- scripts were case series and were excluded.40,41 One article did not use 30 Ncm with immediate loading and was excluded.42 One manuscript was excluded because it reported implants with insertion torque of 30 Ncm loaded within 72 hours.43 Thus, a total of 6 studies44–49 met the selection criteria and were submitted to the qualitative analysis (Fig. 1). Only one correspond- ing author replied to the email with no unpublished data. All CTs included in this review were conducted in Italy.44–49 Four stud- ies were conducted with a parallel group design.44,45,48,49 One was con- ducted with split-mouth design47 and onewas noncontrolled, nonrandomized clinical trial.46 Two days was the most common loading time for implants with 30 Ncm of insertion torque.44,45,49 In 3 clinical trials, the dental implants were placed only in the mandible.46–48 In the other clinical trials, implants were in- serted in upper and lower jaws.44,45,49 Themain characteristics of the 6 studies are summarized in Table 2. Insertion torque was measured dur- ing the setting of the dental implant using an electronic device (OsseoCare, Nobel Biocare, Switzerland).44–49 Among all clinical trials, 31 dental implants were inserted with insertion torque of 30Ncm and loaded immediately and on- ly one implant had failed in the follow- up,47 which constitutes a 96.8% survival rate for this type of dental implant. One clinical trial did not mention the sample size.46 Five studies presented appropriate statistical analysis.44,45,47–49 Table 1. Variables Used to Assess Quality of Included Clinical Trials Sample-size calculation, estimating the minimum number of participants required to detect a significant difference among compared groups 0 ¼ did not exist/not mentioned/not clear 1 ¼ reported but not confirmed 2 ¼ reported and confirmed Allocation concealment 0 ¼ inadequate 1 ¼ possibly adequate 2 ¼ clearly adequate Random Allocation 0 ¼ inadequate 1 ¼ possibly adequate 2 ¼ clearly adequate Losses (specified reasons for withdrawals and dropouts in each study group) 0 ¼ no/not mentioned/not clear 1 ¼ yes/no withdrawals or dropouts occurred Blinding of assessors 0 ¼ no 1 ¼ unclear/not complete 2 ¼ yes Appropriate statistical analysis 0 ¼ no 1 ¼ unclear/possibly not the best method applied 2 ¼ yes Fig. 1. Representative flow chart for the search results. Total of identified and excluded ar- ticles and the final studies is included. DOUGLAS DE OLIVEIRA ET AL IMPLANT DENTISTRY / VOLUME 25, NUMBER 5 2016 677 Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Table 2. Characteristics of Studies Included in Present Systematic Review Study Study Design Country Participants Loading Time (d) for 30N Immediate Implants Occlusal Contact for 30N Immediate Implants Total No. of Implants No. of 30N Implants No. of Drop-Outs Capelli et al44 Randomized Clinical Trial, parallel group Italy 23 males, 29 females; 27–74 y 2 No 104 6 1 Galli et al45 Randomized Clinical Trial, parallel group Italy 23 males, 29 females; 27–74 y 2 No 104 6 0 Marzola et al46 Clinical trial not controlled not randomized Italy 6 males, 11 females; 36–91 y 0 Yes 34 8 0 Schincaglia et al47 Randomized Clinical Trial, split-mouth Italy 6 males, 4 females; 37–74 y 1 Yes 42 4 0 Schincaglia et al48 Randomized Clinical Trial, parallel group Italy 9 males, 21 females; 31–75 y 1 Yes 30 1 0 Testori et al49 Randomized Clinical Trial, parallel group Italy 23 males, 29 females; 27–74 y 2 No 104 6 0 Study Follow- Up, mo Jaw Prothesis Type Implant Brand Graft Bone Outcomes No. of Failures of Immediate Implants (30N) Survival Rates for 30N Dental Implant, % Capelli et al44 60 Mixed Unitary and fixed dental prothesis Biomet 3i In some cases Loss of marginal periimplant bone; recession of vestibular soft tissue; prosthesis failure 0 100 Galli et al45 14 Mixed Unitary and fixed dental prothesis Biomet 3i In some cases Loss of marginal periimplant bone; No recession of vestibular soft tissue; prosthesis failure 0 100 Marzola et al46 12 Mandible Denture Nobel Biocare NR Loss of marginal periimplant bone; prosthesis failure 0 100 Schincaglia et al47 12 Mandible Multiple Nobel Biocare NR Loss of marginal periimplant bone; prosthesis failure 1 75 Schincaglia et al48 12 Mandible Unitary Nobel Biocare NR Loss of marginal periimplant bone 0 100 Testori et al49 14 Mixed Unitary and fixed dental prothesis Biomet 3i In some cases Loss of marginal periimplant bone; No recession of vestibular soft tissue; prosthesis failure 0 100 678 IN S E R T IO N T O R Q U E O F 30 N C M D O U G L A S D E O L IV E IR A E T A L Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. The risk of bias was considered low in 3 studies44,45,49 and high in the other clin- ical trials analyzed (Table 3).46–48 A reduction in marginal peri- implant bone was reported in all studies reviewed.44–49 No postoperative com- plications were reported in any study. One study reported the occurrence of peri-implantitis44 and one clinical trial described gingival recession after implant placement.44 Five studies re- ported prosthesis failures.44–47,49 The data extracted from the studies evaluated in the present review reveal heterogeneity in relation to the follow- up period, clinical parameters assessed, implant dimensions, and study design; in other words, the studies seem to have methodological heterogeneity. Thus, it was not possible to establish a quantita- tive synthesis of the data, thereby rendering meta-analysis impossible. DISCUSSION Previous systematic reviews report the use of dental implants (loaded immediately or not) for the treatment of partially and completely edentulous jaws with excellent clinical outcomes, patient satisfaction, and high survival rates.50–54 However, a gap remains in current knowledge on the minimum insertion torque necessary for implants submitted to immediate loading. As shorter treatment time is a major desire of patients, such research is essential. This is the first study to focus on this issue based on clinical trials addressing dental implants immediately loaded with insertion torque of 30 Ncm. None of the clinical trials in the present review reported adverse effects from the surgical procedures per- formed. These findings provide evi- dence of the clinical safety of dental implants for replacing missing teeth even in older adults, for whom the prevalence rates of systemic disorders, diseases, and edentulism are high. Edentulism associated with adverse health conditions, such as cardiovascu- lar disease, diabetes mellitus, kidney disease, and coronary disease, has been investigated in several studies.55–58 The high success rate of dental im- plants has led to safe treatment and an improvement in quality of life.59 Despite the advantages of dental implants, pa- tients complained about longhealing time and hence immediate loading was devel- oped to decrease the treatment time and increase patient comfort and satisfaction. Immediate loading can be used in eden- tulous areas with good clinical and radio- graphic short-term outcomes.60 Indeed, immediate loading is currently fully accepted as a treatment option for the replacement of single or multiple missing teeth in both jaws,61,62 as confirmedby the clinical trials analyzed herein. The period of complete osseointe- gration ranges from 3 to 6 months.51,63 The follow-up period in the studies re- viewed ranged from 12 to 60 months (median: 13 months). The long-term effect of osseointegration could be observed, as the evaluations were per- formed in a period surpassing 6months. The results described by Capelli et al44 are from a longitudinal follow-up (60 months) of patients whose data were published in a previous study.49 The importance of longitudinal studies resides in the demonstration of the long- term results achieved with dental im- plants. Moreover, only the longitudinal clinical trial44 reported the occurrence of peri-implantitis and soft-tissue reces- sions, which demonstrates the chronic aspect of these conditions54,64 and the importance of regular maintenance visits after dental implant placement to prevent or to manage peri-implantitis.65 Primary stability is an important prerequisite for the success of immedi- ate implant loading.66 Thus, the imme- diate loading of dental implants may achieve predictable treatment outcomes if clinical precautions are taken. Such precautions may include under- preparation of the implant sites, partic- ularly in the presence of soft type III and IV bones according to Lekholm and Zarb67 the use of implants that favor stronger, faster bone integration, and accurate loading control.49 Two major factors that influence primary stability of an implant during placement are the amount of bone–implant contact and the role of compressive stresses at the implant–tissue interface. Such stresses may be beneficial for enhancing the primary stability of an implant, but, when too high, can result in necrosis and local ischemia of the bone at the implant–tissue interface.68 As primary implant stability is dependent on the physical connection between the implant and surrounding bone, implant design, bone quality and quantity, and surgical technique all exert an influence.52,69 An electronicdevicewasused for the determination of insertion torque in all studies reviewed.44–49 This methodologi- cal consistency in the assessment of inser- tion torque reflects the ease and standardized protocol in this objective method of evaluating primary stability. Insertion torque can be understood as the insertion force of an implant in an undersized receptor bed. This measure is directly related to primary stability,which suggests that osseointegration can be fast- er and/or improved using a surgical pro- tocol with a high insertion torque. In type III and IV bones,67 the mac- rostructure of the implant plays a crucial Table 3. Risk of Bias in Studies Analyzed Study Sample Size Allocation Concealment Random Allocation Losses Assessors Blinding Statistical Analysis Judged Bias Risk Capelli et al44 2 2 2 1 2 2 Low Galli et al45 2 2 2 1 2 2 Low Marzola et al46 0 0 0 1 0 1 High Schincaglia et al47 2 0 2 1 2 2 High Schincaglia et al48 2 0 2 1 2 2 High Testori et al49 2 2 2 1 2 2 Low DOUGLAS DE OLIVEIRA ET AL IMPLANT DENTISTRY / VOLUME 25, NUMBER 5 2016 679 Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. role in achieving primary stability. Some studies suggest that the implant design may influence the survival rate in different ways.70,71 Unfortunately, the clinical trials analyzed herein did not report on the macrostructure of the implant, which may be considered a source of bias. In the present systematic review, “immediate loading”was considered as the treatment protocol in which a pros- thetic reconstruction is attached to the dental implant within 48 hours follow- ing surgery. Although “immediate” normally implies “directly after,”50 this 48-hours’ time frame is the time neces- sary for the dental technician to process the provisional or definitive restoration and is currently generally accepted in implant dentistry.8,9 There are some advantages to immediate loading that may explain the popularity of this technique and is pref- erence overmediate loading (implant put into function over 48 hours after place- ment),8,9 such as the reduction in treat- ment time, greater patient comfort as well as esthetic and economic benefits, especially for professionally and/or socially active patients.50 The CTs in this review used immediate loadingwith46–48 or without44–49 occlusal contact of the restorationwith the opposing arch.How- ever, the lack of occlusion does not impede a restoration from being func- tional during mastication. The influence of occlusal contact on implant survival could not be verified, since all studies reported a high survival rate and a low failure rate of the dental implants and prosthesis. According to Misch et al,72 immediate nonocclusal loading consists of modifying the immediate temporary restoration to avoid occlusal contacts in centric and lateral excursions and reduce the risk of early mechanical overload caused by functional or parafunctional forces. The findings of a previous sys- tematic review demonstrate that differ- ences in occlusal loading between implants with immediate functional loading and immediate nonfunctional loading do not affect the survival rate.51 Four CTs44,45,48,49 also investigated dental implants with mediate loading and report a dental implant survival rate similar to that achieved with immediate loading. However, the clinical trials did not show the direct impact of the load- ing protocol on implant survival, since the variation in survival was visibly smaller with delayed loading (100%) in comparison to immediate loading (93.3%–100%). The issue of whether implants could be immediately loaded after their insertion was the subject in a previous study,73 which demonstrated a low fail- ure rate for all loading times.Moreover, the authors suggest that, under ideal conditions, surgeons can achieve a high success rate when loading implants immediately, early or conventionally. In 14 months of follow-up, authors observed mean peri-implant bone loss of 1.1 mm with immediately loaded implants.45,49 Five years later, the same research presented a mean bone loss of 1.2mm.44 These results were confirmed by Schincaglia et al,48 who reported bone loss of 1.2 mm in the period of 12months after implant placement with immediate loading, whereas bone loss of 0.77 mm was found with delayed loading. This difference was statisti- cally significant. As noted in the present review, resorption is part of physiolog- ical remodeling during osseointegra- tion and also occurs with immediate loading.74 Descriptive data fromall studies44–49 in the present review reveal a high rate of dental implant survival in cases of immediate loading with insertion tor- que of 30 Ncm. However, the studies reviewed were limited regarding the statistical analysis to determine the behavior of 30 Ncm insertion torque. In other words, no statistical evidence was presented of the effectiveness of this insertion torque value regarding the stability and survival rate of imme- diately loaded implants. Thus, it is not possible to rule out the occurrence of type I (false positive) or II (false nega- tive) errors. Moreover, higher insertion torque may not always translate to greater primary stability true, as bone quantity and quality vary significantly among patients.68 Many factors are not distributed equally among populations worldwide and may influence the results of imme- diate implant loading, such as aspects related to the surgery, host, implant, and occlusion, including bone quality, dietary habits, wound healing, implant design and surface, prosthetic design, bite force, professional experience, and patient expectations.48,63,75–77 In the present systematic review, all CTs on dental implants set at 30 Ncm with immediately loading were conducted in Italy.45–50 This finding underscores the need for further studies, involving different populations that correlate 30 Ncm torque with immediate loading for a better comparison and reliability of the results. The risk of bias was considered high in 3 studies.46–49 The factor that most compromised methodological quality was the lack of allocation con- cealment. Without adequate allocation concealment, even randomized, unpre- dictable sequences can be corrupted.78 The operator may intervene, tending to favor one group over another, which leads to selection bias. According to Schulz,78 an inadequately concealed allocation sequence can produce greater estimated treatment effects. In future studies, this bias can be avoided by using, for example, central randomiza- tion or sequentially numbered, sealed, opaque envelopes. It is important to note that the studies by Galli et al (2008)44 and Testori et al49 seem to report the same results from the same population regarding the outcomes investigated in this review, especially the total number and survival rates of implants inserted with torque of 30 Ncm. The only differ- ence between these clinical trials is that Testori et al49 published data on resto- ration success, implant success, and complications. Therefore, the results of both articles should be viewed as on- ly one in this review. A protocol was used to guide the search strategy, study selection, and data collection. However, the present systematic review may have some lim- itations, such as the absence of meta- analysis and the noninclusion of the EMBASE database due tomethodolog- ical and logistical reasons. Moreover, some potentially relevant trials were excluded due to the lack of information on the number dental implants inserted with torque of 30 Ncm and such information was not obtained from the authors. 680 INSERTION TORQUE OF 30 NCM DOUGLAS DE OLIVEIRA ET AL Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. Well-conducted, randomized, con- trolled trials with good methodological quality and long-term postoperative follow-up are needed to corroborate or refute the findings of this systematic review. Future studies should focus on implants with insertion torque of 30 Ncm and submitted to immediate loading. CONCLUSION The results of the present systematic review must be viewed with caution, as half of the studies reviewed had a high risk of bias and 3 articles arose from the same research.On the basis of the studies included in this review, there is not strong evidence to conclude that inser- tion torque of 30 Ncm is enough for implant survival in cases of immediate loading, although the results demon- strated a high survival rate. Adequately powered randomized clinical trials are needed to allow clinicians to load dental implants immediately with insertion tor- que of 30 Ncm as safe, lasting treatment for missing teeth. DISCLOSURE The authors claim to have no financial interest, either directly or indirectly, in the products or informa- tion listed in the paper. The study was self-supported by the authors. ACKNOWLEDGMENTS The authors would like to thank Professor Marco Esposito for replied the e-mail. REFERENCES 1. Wang RE, Lang NP. Ridge preser- vation after tooth extraction. Clin Oral Im- plants Res. 2012;23:S147–S156. 2. Brånemark PI, Engstrand P, Ohrnell LO, et al. Brånemark Novum: A new treat- ment concept for rehabilitation of the edentulous mandible. Preliminary results from a prospective clinical follow-up study. Clin Implant Dent Relat Res. 1999;1:2–16. 3. Adell R, Eriksson B, Lekholm U, et al. Long-term follow-up study of osseointe- grated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants. 1990;5:347–359. 4. Esposito M, Grusovin MG, Chew YS, et al. A Cochrane systematic review of randomized controlled clinical trials. Eur J Oral Implantol. 2009;2:91–99. 5. Esposito M, Grusovin MG, Achille H, et al. Interventions for replacing missing teeth: Different times for loading dental im- plants. Cochrane Database Syst Rev. 2009:CD003878. 6. Brånemark P, Zarb GA, Albrektsson T. Tissue-Integrated Prostheses: Osseoin- tegration in Clinical Dentistry. Berlin, Ger- many: Quintessence; 1985:11–53. 7. Avila G, Galindo P, Rios H, et al. Immediate implant loading: Current status from available literature. Implant Dent. 2007;16:235–245. 8. Misch CE, Wang HL, Misch CM, et al. Rationale for the application of imme- diate load in implant dentistry: Part I. Implant Dent. 2004;13:207–217. 9. Misch CE, Wang HL, Misch CM, et al. Rationale for the application of imme- diate load in implant dentistry: Part II. Implant Dent. 2004;13:310–321. 10. Meloni SM, De Riu G, Pisano M, et al. Immediate versus delayed loading of single mandibular molars. One-year re- sults from a randomized controlled trial. Eur J Oral Implantol. 2012;5:345–353. 11. Thomé E, Lee HJ, Sartori IA, et al. A randomized controlled trial comparing interim acrylic prostheses with and without cast metal base for immediate loading of dental implants in the edentulous mandible. Clin Oral Implants Res. 2014;26:1414–1420. 12. Crespi R, Vinci R, Capparé P, et al. A clinical study of edentulous patients rehabilitated according to the “all on four” immediate function protocol. Int J Oral Maxillofac Implants. 2012;27:428–434. 13. Degidi M, Piattelli A. 7-year follow- up of 93 immediately loaded titanium dental implants. J Oral Implantol. 2005;31:25–31. 14. Wöhrle PS. Single-tooth replace- ment in the aesthetic zone with immediate provisionalization: Fourteen consecutive case reports. Pract Periodontics Aesthet Dent. 1998;10:1107–1114. 15. Ottoni JM, Oliveira ZF, Mansini R, et al. Correlation between placement tor- que and survival of single-tooth implants. Int J Oral Maxillofac Implants. 2005;20: 769–776. 16. Pozzi A, Sannino G, Barlattani A. Minimally invasive treatment of the atrophic posterior maxilla: A proof-of-concept pro- spective study with a follow-up of between 36 and 54 months. J Prosthet Dent. 2012; 108:286–297. 17. Pieri F, Aldini NN, Fini M, et al. Immediate fixed implant rehabilitation of the atrophic edentulous maxilla after bilat- eral sinus floor augmentation: A 12-month pilot study. Clin Implant Dent Relat Res. 2012;14:e67–e82. 18. Simunek A, Strnad J, Kopecka D, et al. Changes in stability after healing of immediately loaded dental implants. Int J Oral Maxillofac Implants. 2010;25:1085– 1092. 19. Papaspyridakos P, Chen CJ, Chuang SK, et al. Implant loading proto- cols for edentulous patients with fixed prostheses: A systematic review and meta-analysis. Int J Oral Maxillofac Im- plants. 2014;29:S256–S270. 20. Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for system- atic reviews and meta-analyses: The PRIS- MA statement. PLoS Med. 2009;6: e1000097. 21. Higgins JPT, Green S, eds. Co- chrane Handbook for Systematic Reviews of Interventions Version 5.1.0. The Co- chrane Collaboration; 2011. Available at: www.cochrane-handbook.org. Accessed July 29, 2014. 22. Moher D, Hopewell S, Schulz KF, et al. Consort 2010 explanation and elab- oration: Updated guidelines for reporting parallel group randomized trials. Int J Surg. 2012;10:28–55. 23. Degidi M, Nardi D, Piattelli A. Immediate versus one-stage restoration of small-diameter implants for a single missing maxillary lateral incisor: A 3-year randomized clinical trial. J Periodontol. 2009;80:1393–1398. 24. Degidi M, Nardi D, Piattelli A. A comparison between immediate loading and immediate restoration in cases of partial posterior mandibular edentulism: A 3-year randomized clinical trial. Clin Oral Implants Res. 2010;21:682–687. 25. Degidi M, Daprile G, Piattelli A. Im- plants inserted with low insertion torque values for intraoral welded full-arch pros- thesis: 1-year follow-up. Clin Implant Dent Relat Res. 2012;14:e39–e45. 26. Grandi T, Garuti G, Guazzi P, et al. Survival and success rates of immediately and early loaded implants: 12-month re- sults from a multicentric randomized clini- cal study. J Oral Implantol. 2012;38:239– 249. 27. Grandi T, Guazzi P, Samarani R, et al. Immediate loading of two unsplinted implants retaining the existing complete mandibular denture in elderly edentulous patients: 1-year results from a multicentre prospective cohort study. Eur J Oral Im- plantol. 2012;5:61–68. 28. Romanos GE, May S, May D. Treatment concept of the edentulous mandible with prefabricated telescopic abutments and immediate functional load- ing. Int J Oral Maxillofac Implants. 2011; 26:593–597. 29. Malchiodi L, Ghensi P, Cucchi A, et al. A comparative retrospective study of immediately loaded implants in postextraction DOUGLAS DE OLIVEIRA ET AL IMPLANT DENTISTRY / VOLUME 25, NUMBER 5 2016 681 Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. sites versus healed sites: Results after 6 to 7 years in the maxilla. Int J Oral Maxillofac Im- plants. 2011;26:373–384. 30. Gillot L, Cannas B, Buti J, et al. A retrospective cohort study of 113 patients rehabilitated with immediately loaded max- illary cross-arch fixed dental prostheses in combination with immediate implant placement. Eur J Oral Implantol. 2012;5: 71–79. 31. Barewal RM, Stanford C, Weesner TC. A randomized controlled clinical trial comparing the effects of three loading pro- tocols on dental implant stability. Int J Oral Maxillofac Implants. 2012;27:945–956. 32. Cannizzaro G, Leone M, Ferri V, et al. Immediate loading of single implants inserted flapless with medium or high insertion torque: A 6-month follow-up of a split-mouth randomized controlled trial. Eur J Oral Implantol. 2012;5:333–342. Erra- tum in: Eur J Oral Implantol. 2013;6:260. 33. Crespi R, Capparè P, Gherlone E, et al. Immediate provisionalization of dental implants placed in fresh extraction sockets using a flapless technique. Int J Periodon- tics Restorative Dent. 2012;32:29–37. 34. Fung K, Marzola R, Scotti R, et al. A 36-month randomized controlled split- mouth trial comparing immediately loaded titanium oxide-anodized and machined im- plants supporting fixed partial dentures in the posterior mandible. Int J Oral Maxillo- fac Implants. 2011;26:631–638. 35. Margossian P, Mariani P, Stephan G, et al. Immediate loading of mandibular dental implants in partially edentulous pa- tients: A prospective randomized compar- ative study. Int J Periodontics Restorative Dent. 2012;32:e51–e58. 36. Peñarrocha-Oltra D, Covani U, Aparicio A, et al. Immediate versus con- ventional loading for the maxilla with im- plants placed into fresh and healed extraction sites to support a full-arch fixed prosthesis: Nonrandomized controlled clinical study. Int J Oral Maxillofac Im- plants. 2013;28:1116–1124. 37. Östman PO, Wennerberg A, Ekestubbe A, et al. Immediate occlusal loading of NanoTite tapered implants: A prospective 1-year clinical and radio- graphic study. Clin Implant Dent Relat Res. 2013;15:809–818. 38. Turkyilmaz I, Avci M, Kuran S, et al. A 4-year prospective clinical and radiolog- ical study of maxillary dental implants sup- porting single-tooth crowns using early and delayed loading protocols. Clin Implant Dent Relat Res. 2007;9:222–227. 39. Scortecci G. Immediate function of cortically anchored disk-design implants without bone augmentation in moderately to severely resorbed completely edentu- lous maxillae. J Oral Implantol. 1999;25: 70–79. 40. Jensen OT, Cottam J, Ringeman J, et al. Trans-sinus dental implants, bone morphogenetic protein 2, and immediate function for all-on-4 treatment of severe maxillary atrophy. J Oral Maxillofac Surg. 2012;70:141–148. 41. Cricchio G, Imburgia M, Sennerby L, et al. Immediate loading of implants placed simultaneously with sinus mem- brane elevation in the posterior atrophic maxilla: A two-year follow-up study on 10 patients. Clin Implant Dent Relat Res. 2014;16:609–617. 42. Grandi T, Guazzi P, Samarani R, et al. A 3-year report from a multicenter randomized controlled trial: Immediately versus early loaded implants in partially edentulous patients. Eur J Oral Implantol. 2013;6:217–224. 43. Merli M, Merli A, Bernardelli F, et al. Immediate versus early non-occlusal load- ing of dental implants placed flapless in partially edentulous patients. One-year re- sults from a randomized controlled trial. Eur J Oral Implantol. 2008;1:207–220. 44. Capelli M, Esposito M, Zuffetti F, et al. A 5-year report from a multicentre randomized clinical trial: Immediate non- occlusal versus early loading of dental im- plants in partially edentulous patients. Eur J Oral Implantol. 2010;3:209–219. 45. Galli F, Capelli M, Zuffetti F, et al. Immediate non-occlusal vs. early loading of dental implants in partially edentulous pa- tients: A multicentre randomized clinical trial. Peri-implant bone and soft-tissue levels. Clin Oral Implants Res. 2008;19:546–552. 46. Marzola R, Scotti R, Fazi G, et al. Immediate loading of two implants support- ing a ball attachment-retained mandibular overdenture: A prospective clinical study.Clin Implant Dent Relat Res. 2007;9:136–143. 47. Schincaglia GP, Marzola R, Scapoli C, et al. Immediate loading of dental im- plants supporting fixed partial dentures in the posterior mandible: A randomized con- trolled split-mouth study–machined versus titanium oxide implant surface. Int J Oral Maxillofac Implants. 2007;22:35–46. 48. Schincaglia GP, Marzola R, Giovanni GF, et al. Replacement of man- dibular molars with single-unit restorations supported by wide-body implants: Imme- diate versus delayed loading. A random- ized controlled study. Int J Oral Maxillofac Implants. 2008;23:474–480. 49. Testori T, Galli F, Capelli M, et al. Immediate nonocclusal versus early load- ing of dental implants in partially edentu- lous patients: 1-year results from a multicenter, randomized controlled clini- cal trial. Int J Oral Maxillofac Implants. 2007;22:815–822. 50. De Bruyn H, Raes S, Ostman PO, et al. Immediate loading in partially and completely edentulous jaws: A review of the literature with clinical guidelines. Perio- dontol 2000. 2014;66:153–187. 51. Chrcanovic BR, Albrektsson T, Wennerberg A. Immediate nonfunctional versus immediate functional loading and dental implant failure rates: A systematic review and meta-analysis. J Dent. 2014; 42:1052–1059. 52. Duyck J, Vandamme K. The effect of loading on peri-implant bone: A critical review of the literature. J Oral Rehabil. 2014;41:783–794. 53. Menassa M, de Grandmont P, Audy N, et al. Patients’ expectations, sat- isfaction, and quality of life with immediate loading protocol. Clin Oral Implants Res. 2016;27:83–89. 54. Glauser R, Zembic A, Hämmerle CH. A systematic review of marginal soft tissue at implants subjected to immediate loading or immediate restoration. Clin Oral Implants Res. 2006;17:s82–s92. 55. Osterberg T, Dey DK, Sundh V, et al. Edentulism associated with obesity: A study of four national surveys of 16 416 Swedes aged 55–84 years. Acta Odonto- logica Scand. 2010;68:360–367. 56. Medina-Solis CE, Perez-Nunez R, Maupome G, et al. Edentulism among Mexican adults aged 35 years old and associated factors. Amer J Pub Health. 2006;96:1578–1581. 57. de Pablo P, Dietrich T, McAlindon TE. Association of periodontal disease and tooth loss with rheumatoid arthritis in the US population. J Rheumatol. 2008;35:70–76. 58. Fisher MA, Taylor GW, Shelton BJ, et al. Periodontal disease and other non- traditional risk factors for CKD. Am J Kid- ney Dis. 2008;51:45–52. 59. Albrektsson T, Gottlow J, Meirelles L, et al. Survival of NobelDirect implants: An analysis of 550 consecutively placed implants at 18 different clinical centers. Clin Implant Dent Relat Res. 2007;9:65–70. 60. Fischer K, Stenberg T, Hedin M, et al. Five-year results from a randomized, controlled trial on early and delayed load- ing of implants supporting full-arch pros- thesis in the edentulous maxilla. Clin Oral Implants Res. 2008;19:433–441. 61. Pjetursson BE, Rast C, Bragger U, et al. Maxillary sinus floor elevation using the (transalveolar) osteotome technique with or without grafting material: Part I: Implant survival and patients’ perception. Clin Oral Implants Res. 2009;20:667–676. 62. Jung RE, Pjetursson BE, Glauser R, et al. A systematic review of the 5- year survival and complication rates of implant-supported single crowns. Clin Oral Implants Res. 2008;19:119–130. 63. Gapski R, Wang HL, Mascarenhas P, et al. Critical review of immediate implant loading. Clin Oral Implants Res. 2003;14:515–527. 682 INSERTION TORQUE OF 30 NCM DOUGLAS DE OLIVEIRA ET AL Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. 64. Schwarz F, Hegewald A, John G, et al. Four-year follow-up of combined sur- gical therapy of advanced peri-implantitis evaluating two methods of surface decon- tamination. J Clin Periodontol. 2013;40: 962–967. 65. Patel A. Non-surgical management of peri-implant diseases. Prim Dent J. 2014;3:62–65. 66. Tabassum A, Meijer GJ, Walboomers XF, et al. Evaluation of primary and secondary stability of titanium implants using different surgical techniques. Clin Oral Implants Res. 2014;25:487–492. 67. Lekholm U, Zarb GA. Patient selec- tion and preparation. In: Brånemark PI, Zarb GA, Albrektsson T, eds. Tissue Integrated Prostheses: Osseointegration in Clinical Dentistry. Chicago, IL: Quintessence Pub- lishing Company; 1985:199–209. 68. Bayarchimeg D, Namgoong H, Kim BK, et al. Evaluation of the correlation between insertion torque and primary sta- bility of dental implants using a block bone test. J Periodontal Implant Sci. 2013;43: 30–36. 69. Javed F, Romanos GE. The role of primary stability for successful immediate loading of dental implants. A literature review. J Dent. 2010;38:612–620. 70. Javed F, Romanos GE. Role of implant diameter on long-term survival of dental implants placed in posterior maxilla: A systematic review. Clin Oral Investig. 2014;19:1–10. 71. Gehrke SA, da Silva Neto UT, Del Fabro M. Does implant design affect implant primary stability? A resonance frequency analysis-based randomized split-mouth clinical trial. J Oral Implantol. 2015;41:e281–e286. 72. Misch CE. Nonfunctional immedi- ate teeth. Dent Today. 1998;17:88–91. 73. Esposito M, Grusovin MG, Maghaireh H, et al. Interventions for re- placing missing teeth: Different times for loading dental implants. Cochrane Data- base Syst Rev. 2013;28:CD003878. 74. Götz W, Gedrange T, Bourauel C, et al. Clinical, biomechanical and biolog- ical aspects of immediately loaded dental implants: A critical review of the literature. Biomed Tech (Berl). 2010;55: 311–315. 75. Guncu MB, Aslan Y, Tumer C, et al. In-patient comparison of immediate and conventional loaded implants in man- dibular molar sites within 12 months. Clin Oral Implants Res. 2008;19:335–341. 76. Cornelini R, Cangini F, Covani U, et al. Immediate restoration of single- tooth implants in mandibular molar sites: A 12-month preliminary report. Int J Oral Maxillofac Implants. 2004;19:855–860. 77. Adell R, Lekholm U, Rockler B, et al. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg. 1981;10:387–416. 78. Schulz KF. Randomized trials, human nature, and reporting guidelines. Lancet. 1996;348:596–598. DOUGLAS DE OLIVEIRA ET AL IMPLANT DENTISTRY / VOLUME 25, NUMBER 5 2016 683 Copyright � 2016 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.