Back to the Journal

Guided surgery for single-implant placement: A critical review

January 6, 2017 / Categories: Digital Dentistry, Implant Dentistry

Tallarico, Marco

Meloni, Silvio Mario

Canullo, Luigi

Xhanari, Erta

Giovanni, Polizzi

Table of Contents

• Introduction
• Materials and methods
  • Search Strategy
• Results
  • Accuracy of computer-assisted, template-based surgery for implant-supported single-tooth restorations
  • Esthetic outcomes of implant-supported single-tooth restorations performed using computer-assisted, template-based surgery
  • Clinical outcomes of implant-supported single-tooth restorations performed using computer-assisted, tempplate-based surgery
• Conclusion
• Competing interests
• Acknowledgments
• Interview
  • with Tallarico Marco

The objective of this review was to evaluate the scientific evidence on accuracy, as well as esthetic and clinical outcomes of single-tooth implants placed using computer-assisted, template-based surgery.

Periimplant soft-tissue esthetics represents one of the major aspect of implant success, particularly in the anterior maxilla, and it may be a main factor in the patient’s decision on implant therapy, rather than a conventional fixed or removable dental prosthesis.³Chen ST, Buser D. Esthetic outcomes following immediate and early implant placement in the anterior maxilla a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:186–215. It is well established that sufficient bone volume and a favorable 3-D implant position are prerequisites for long-term functional and esthetic success.⁴Chen ST, Buser D. Esthetic outcomes following immediate and early implant placement in the anterior maxilla—a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:186–215.⁵Grunder U, Gracis S, Capelli M. Influence of the 3-D bone-to-implant relationship on esthetics.
→ Int J Periodontics Restorative Dent. 2005 Apr;25(2):113–19.⁶Buser D, Martin WC, Belser UC. Optimizing esthetics for implant restorations in the anterior maxilla: anatomic and surgical considerations.
→ Int J Oral Maxillofac Implants. 2004;19 Suppl:43–61. However, alveolar bone resorption after tooth loss seems to be inevitable with both immediate and delayed implant placement6 and loading.⁷ Esposito M, Grusovin MG, Maghaireh H, Worthington HV. Interventions for replacing missing teeth: different times for loading dental implants.
→ Cochrane Database Syst Rev. 2013 Mar;(3):CD003878. Consequently, prosthetically guided implant positioning might be difficult to achieve.

In recent years, the growing interest in prosthetically guided implant placement, together with the option of fitting prostheses with immediate function, has led to the development of software that integrates the restorative treatment plan (computer-assisted) with minimally invasive (template-based) surgery,⁸Sicilia A, Botticelli D, Working Group 3. Computer-guided implant therapy and soft- and hard-tissue aspects. The third EAO Consensus Conference 2012.
→ Clin Oral Implants Res. 2012 Oct;23 Suppl 6:157–61.⁹ Vasak C, Kohal RJ, Lettner S, Rohner D, Zechner W. Clinical and radiological evaluation of a template-guided (NobelGuide™) treatment concept.
→ Clin Oral Implants Res. 2014 Jan;25(1):116–23.¹⁰ Vasak C, Watzak G, Gahleitner A, Strbac G, Schemper M, Zechner W. Computed tomography-based evaluation of template (NobelGuide™)-guided implant positions: a prospective radiological study.
→ Clin Oral Implants Res. 2011 Oct;22(10):1157–63.¹¹ Klein M, Abrams M. Computer-guided surgery utilizing a computer-milled surgical template.
→ Pract Proced Aesthet Dent. 2001 Mar;13(2):165–9.¹² Pozzi A, Tallarico M, Marchetti M, Scarfo B, Esposito M. Computer-guided versus free-hand placement of immediately loaded dental implants: 1-year post-loading results of a multicentre randomised controlled trial.
→ Eur J Oral Implantol. 2014 Autumn;7(3):229–42. along with reduced treatment time and postoperative discomfort. ¹³ Pozzi A, Tallarico M, Marchetti M, Scarfo B, Esposito M. Computer-guided versus free-hand placement of immediately loaded dental implants: 1-year post-loading results of a multicentre randomised controlled trial.
→ Eur J Oral Implantol. 2014 Autumn;7(3):229–42. Guided implant surgery using cone beam computed tomography (CBCT), virtual treat ment planning software and stereolithographic surgical templates has undoubtedly been a major step toward achieving optimal 3-D implant positioning with respect to both anatomical and prosthetic parameters. Computer-assisted, template-based implant placement offers the potential for better predictability and flapless implant surgery, resulting in reduced intraoperative discomfort and postoperative morbidity.¹⁴ Pozzi A, Tallarico M, Marchetti M, Scarfo B, Esposito M. Computer-guided versus free-hand placement of immediately loaded dental implants: 1-year post-loading results of a multicentre randomised controlled trial.
→ Eur J Oral Implantol. 2014 Autumn;7(3):229–42. It also shortens the overall surgery time.

After enthusiastic preliminary reports,¹⁵Van Steenberghe D, Glauser R, Blombäck U, Andersson M, Schutyser F, Pettersson A, Wendelhag I. A computed tomographic scan-derived customized surgical template and fixed prosthesis for flapless surgery and immediate loading of implants in fully edentulous maxillae: a prospective multicenter study.
→ Clin Implant Dent Relat Res. 2005 Jun;7 Suppl 1:S111–20.¹⁶Sanna AM, Molly L, van Steenberghe D. Immediately loaded CAD-CAM manufactured fixed complete dentures using flapless implant placement procedures: a cohort study of consecutive patients.
→ J Prosthet Dent. 2007 Jun;97(6):331–9. some independent prospective studies¹⁷ Vasak C, Kohal RJ, Lettner S, Rohner D, Zechner W. Clinical and radiological evaluation of a template-guided (NobelGuide™) treatment concept.
→ Clin Oral Implants Res. 2014 Jan;25(1):116–23.¹⁸ Vasak C, Watzak G, Gahleitner A, Strbac G, Schemper M, Zechner W. Computed tomography-based evaluation of template (NobelGuide™)-guided implant positions: a prospective radiological study.
→ Clin Oral Implants Res. 2011 Oct;22(10):1157–63.¹⁹Komiyama A, Klinge B, Hultin M. Treatment outcome of immediately loaded implants installed in edentulous jaws following computer-assisted virtual treatment planning and flapless surgery.
→ Clin Oral Implants Res. 2008 Jul;19(7):677–85.²⁰Johansson B, Friberg B, Nilson H. Digitally planned, immediately loaded dental implants with prefabricated prostheses in the reconstruction of edentulous maxillae: a 1-year prospective, multicenter study.
→ Clin Implant Dent Relat Res. 2009 Sep;11(3):194–200.
²¹Merli M, Bernardelli F, Esposito M. Computer-guided flapless placement of immediately loaded dental implants in the edentulous maxilla: a pilot prospective case series.
→ Eur J Oral Implantol. 2008 Spring;1(1):61–9. drew attention to the potential deviations of 3-D directions between virtual planning and the actual final position of the implant. This approach is technique-sensitive and perioperative complications have to be taken into account.

Although, in general, tooth-supported templates are more accurate than mucosa-supported ones,²²Sicilia A, Botticelli D, Working Group 3. Computer-guided implant therapy and soft- and hard-tissue aspects. The third EAO Consensus Conference 2012.
→ Clin Oral Implants Res. 2012 Oct;23 Suppl 6:157–61. the application of guided surgery to enhance single-tooth implant positioning and esthetic outcome has not been widely reported in the literature. Potential advantages of flapless implant placement in the esthetic zone may include reduced mucosal recession and maximum preservation of periimplant papillae.²³ Buser D, Martin WC, Belser UC. Optimizing esthetics for implant restorations in the anterior maxilla: anatomic and surgical considerations.
→ Int J Oral Maxillofac Implants. 2004;19 Suppl:43–61.
²⁴Belser UC, Grütter L, Vailati F, Bornstein MM, Weber HP, Buser D. Outcome evaluation of early placed maxillary anterior single-tooth implants using objective esthetic criteria: a cross-sectional, retrospective study in 45 patients with a 2- to 4-year follow-up using Pink and White Esthetic Scores.
→ J Periodontol. 2009 Jan;80(1):140–51.²⁵Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27.

Computer-assisted, template-based implant placement may help clinicians to perform successful implant therapy avoiding elevation of large flaps or even eliminating flaps completely, causing less pain and discomfort to patients.²⁶ Pozzi A, Tallarico M, Marchetti M, Scarfo B, Esposito M. Computer-guided versus free-hand placement of immediately loaded dental implants: 1-year post-loading results of a multicentre randomised controlled trial.
→ Eur J Oral Implantol. 2014 Autumn;7(3):229–42. One might assume that, in the case of complex anatomy, as well as post-extraction implant placement, both patients and clinicians could benefit from computer-assisted, template-based surgery. In such advanced cases, correct estimation of the bone condition and the implant position, as well as precise drilling, according to the preoperative planning may be essential in ensuring the successful placement of an implant.

The aim of the present critical review was to evaluate the scientific literature regarding accuracy, esthetic, and clinical outcomes of singletooth implants placed using computer-assisted, template-based surgery.

Materials and methods

The review was written according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines (http://www.prisma-statement.org). The protocol of this systematic review was adapted to the PICO format (P = population/patients: patients who received single implants placed using guided surgery; I = intervention: single- implant placement using guided surgery; C = comparator/control: singleimplant placement using a conventional free-hand approach; O = outcomes: accuracy, esthetics and implant survival rate).

Search Strategy

An electronic literature search was carried out with the intention of collecting relevant information about the accuracy, clinical application and esthetic outcomes of single implants placed using computer-assisted, template-based surgery. The following electronic databases were consulted: PubMed database of the U.S. National Library of Medicine, Scopus scientific abstract and citation database and the Cochrane Library. In accordance with the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist, the grey literature in the New York Academy of Medicine Grey Literature Report was screened in order to find possible unpublished works.

The electronic databases were searched using the following MeSH (Medical Subject Headings) terms: (“Surgery, Computed/r-Assisted”[Mesh] OR “Therapy, Computed/r-Assisted”[Mesh] OR “Computer-Aided Design”[Mesh]) AND (“Dental/ Oral Implants”[Mesh] OR “Dental Implants, Single-Tooth”[Mesh] OR “Dental Prosthesis, Implant-Supported”[Mesh]). Free-text terms (“Implant treatment” OR “Computed guided” OR “Single-tooth gap” OR “Guided surgery”) were added to all searches.

The initial search included data from human, ex vivo and in vitro studies written in English and published between 2002 and May 2015 in refereed journals. No restrictions were implemented regarding the study design. The search included original research, clinical reports, technical notes and systematic reviews. Studies using static computer-assisted, template-based implant systems and dynamic navigation systems were included in the present review. All of the abstracts were evaluated according to established criteria on the topics of this review, in order to select relevant manuscripts for further fulltext evaluation. For evaluation of randomized controlled or comparative studies, it was required that the enrolled population have at least five patients in each group. Clinical reports and technical notes were considered of interest when providing relevant scientific information on the subject. For evaluation of implant and prosthodontic survival rates, it was required that patients had been followed for at least one year after implant placement. However, no specific follow-up period was required for evaluation of surgical or prosthetic complications during implant placement/ loading or for assessing patient-centered outcomes of surgery and the immediate postoperative period.

Afterward, manual searches of the reference lists of selected manuscripts were conducted, limited to the following journals: Clinical Implant Dentistry and Related Research, Clinical Oral Implants Research, International Journal of Oral and Maxillofacial Implants, International Journal of Computerized Dentistry and European Journal of Oral Implantology. Additionally, a new search excluding “Dental/Oral Implants, Single-Tooth” from the previously used MeSH terms was performed, followed by a manual search, in order to find single-tooth dental implants placed using computer-assisted, template-based surgery in larger cohorts of patients. The authors of each selected manuscript were contacted, if necessary, in order to obtain missing or supplementary information. Finally, the authors of the current review used personal contacts in an attempt to identify unpublished or ongoing eligible studies. Two reviewers (MT and SMM) performed the literature search independently. A third reviewer (LC) reassessed both the included and excluded studies.

The following outcome variables were defined:

• accuracy, defined as the difference in location or angulation between the computer planning and the actual position of the placed implant: deviation at the entry point, deviation at the apex, deviation in height and deviation of the axis;
•  esthetic outcome: Pink Esthetic Score (PES);
•  clinical outcomes: implant and prosthetic survival and success rates, any biological and biomechanical complications, and marginal bone loss.

Based on randomized controlled trials in previously published systematic reviews, the following question was addressed: Is there scientific evidence to support the hypothesis that there is a clinical advantage of using computer-assisted, template-based implant placement compared with conventional treatment protocols for the placement of an implant-supported single-tooth restoration?

Results

A total of 706 potentially relevant titles and abstracts were found during the electronic (n = 704) and manual (n = 2) searches. During the first stage of study selection, 563 publications were excluded based on their title and abstract (inter-reviewer agreement k = 0.78). For the second stage, the full texts of the remaining 143 publications were thoroughly evaluated. A total of 125 papers had to be excluded at this stage because they did not fulfill the inclusion criteria of the present review (inter-reviewer agreement k = 0.99). Three manuscripts were added from the reference lists of all of the selected full-text articles. Finally, a total of 21 articles were selected that fulfilled the inclusion criteria of and quality assessment required for this critical review.

The 21 selected studies included one in vitro comparative study,²⁷Kramer FJ, Baethge C, Swennen G, Rosahl S. Navigated vs. conventional implant insertion for maxillary single tooth replacement.
→ Clin Oral Implants Res. 2005 Feb;16(1):60–8. four prospective singlecohort studies,²⁸Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27.²⁹Pozzi A, Moy PK. Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.
→ Clin Implant Dent Relat Res. 2014 Aug;16(4):582–93.³⁰Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23.³¹Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45. one case series,³²Kamposiora P, Papavasiliou G, Madianos P. Presentation of two cases of immediate restoration of implants in the esthetic region, using facilitate software and guides with stereolithographic model surgery prior to patient surgery.
→ J Prosthodont. 2012 Feb;21(2):130–7. six case reports,³³Bonaudo D, Raimondo C, Rubino G. Single-tooth restorative treatment using an immediate-loading CAD/CAM technique.
→ Int J Comput Dent. 2006 Winter;9(4):321–31.
³⁴ Margonar R, Queiroz TP, Luvizuto ER, Santos PL, Wady AF, Paleari AG. Anterior tooth rehabilitation with frozen homogenous bone graft and immediately loaded titanium implant using computer-guided surgery.
→ J Craniofac Surg. 2012 Sep;23(5):e470–2.³⁵ Almog DM, LaMar J, LaMar FR, LaMar F. Cone beam computerized tomography-based dental imaging for implant planning and surgical guidance, Part 1: single implant in the mandibular molar region.
→ J Oral Implantol. 2006 Apr;32(2):77–81.³⁶ Rossi R, Morales RS, Frascaria M, Benzi R, Squadrito N. Planning implants in the esthetic zone using a new implant 3D navigation system.
→ Eur J Esthet Dent. 2010 Summer;5(2):172–88.³⁷Arnetzl GV, Arnetzl G. From the drilling template to the temporary restoration.
→ Int J Comput Dent. 2009 Winter;12(4):345–55.³⁸Sudbrink SD. Computer-guided implant placement with immediate provisionalization: a case report.
→ J Oral Maxillofac Surg. 2005 Jun;63(6):771–4. eight reviews of the literature,³⁹ Sicilia A, Botticelli D, Working Group 3. Computer-guided implant therapy and soft- and hard-tissue aspects. The third EAO Consensus Conference 2012.
→ Clin Oral Implants Res. 2012 Oct;23 Suppl 6:157–61. ⁴⁰.D’haese J, Van De Velde T, Komiyama A, Hultin M, De Bruyn H. Accuracy andcomplications using computer-designed stereolithographic surgical guides for oral rehabilitation by means of dental implants: a review of the literature.
→ Clin Implant Dent Relat Res. 2012 Jun;14(3):321–35.
⁴¹Hultin M, Svensson KG, Trulsson M. Clinical advantages of computer-guided implant placement: a systematic review.
→ Clin Oral Implants Res. 2012 Oct;23 Suppl 6:124–35.⁴² Jung RE, Schneider D, Ganeles J, Wismeijer D, Zwahlen M, Hämmerle CH, Tahmaseb A. Computer technology applications in surgical implant dentistry: a systematic review.
→ Int J Oral Maxillofac Implants. 2009;24 Suppl:92–109.⁴³Kapos T, Ashy LM, Gallucci GO, Weber HP, Wismeijer D. Computer-aided design and computer-assisted manufacturing in prosthetic implant dentistry.
→ Int J Oral Maxillofac Implants. 2009;24 Suppl:110–7.⁴⁴Tahmaseb A, Wismeijer D, Coucke W, Derksen W. Computer technology applications in surgical implant dentistry: a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:25–42.⁴⁵Widmann G, Bale RJ. Accuracy in computer-aided implant surgery—a review.
→ Int J Oral Maxillofac Implants. 2006 Mar-Apr;21(2):305–13.⁴⁶Schneider D, Marquardt P, Zwahlen M, Jung RE. A systematic review on the accuracy and the clinical outcome of computer-guided template-based implant dentistry.
→ Clin Oral Implants Res. 2009 Sep;20 Suppl 4:73–86. and one randomized controlled trial.⁴⁷Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. A diagram of the search strategy is presented in Figure 1.

Accuracy of computer-assisted, template-based surgery for implant-supported single-tooth restorations

There are no in vivo randomized controlled trials in the scientific literature that report on the accuracy of computer-assisted, template-based implant placement compared with a free-hand approach for the treatment of a single-tooth gap. Three in vivo prospective studies, and one randomized controlled trial reported the 3-D accuracy of 65 implants placed using computerassisted, template-based surgery.⁴⁸ Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27. ⁴⁹Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23. ⁵⁰Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45.⁵¹Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. All of the data are summarized in Table 1. Farley et al., in a split-mouth, randomized controlled trial, reported that computer-assisted, template-based implant placement was more accurate than conventional guides, but only for coronal horizontal distances.⁵²Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. One in vitro comparative study (80 implants) reported the 3-D accuracy of single- tooth implants placed using navigated implant surgery compared with conventional implant placement.⁵³Kramer FJ, Baethge C, Swennen G, Rosahl S. Navigated vs. conventional implant insertion for maxillary single tooth replacement.
→ Clin Oral Implants Res. 2005 Feb;16(1):60–8.Kramer et al. compared in vitro the accuracy of conventional (n = 40) versus navigated (n = 40) implant placement.⁵⁴Kramer FJ, Baethge C, Swennen G, Rosahl S. Navigated vs. conventional implant insertion for maxillary single tooth replacement.
→ Clin Oral Implants Res. 2005 Feb;16(1):60–8. For each group, identical maxillary casts were used to place implants for single-tooth replacement of either the left central incisor (n = 20) or the right canine (n = 20). The authors concluded that variation in implant position, angulation and depth was reduced for implants that were placed using the navigation protocol.⁵⁵Kramer FJ, Baethge C, Swennen G, Rosahl S. Navigated vs. conventional implant insertion for maxillary single tooth replacement.
→ Clin Oral Implants Res. 2005 Feb;16(1):60–8.

In a prospective study, Behneke et al. analyzed the factors that may influence the transfer accuracy of CBCT-derived, laboratory-based surgical guides for implant placement in partially edentulous patients.⁵⁶Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23. Nineteen implants were placed to restore a single-tooth gap in 19 partially edentate patients. The accuracy of computer-assisted, template-based implant placement was evaluated using the image fusion technique. Measurements were done to calculate linear and angular deviations between virtually planned and actually placed implants. A relevant improvement of the accuracy could be achieved by final drilling or implant placement with template guidance in both single-tooth gap and reduced residual dentition cases. A mean error of 0.21 ± 0.16 mm (range of 0.01–0.92 mm) at the entry point and of 0.32 ± 0.34 mm (range of 0.03–0.59) at the apex, and 1.35 ± 1.11° (range of 0.07–3.33°) of apex radial deviation were reported for single-tooth gap surgery.⁵⁷Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23. The amount of coronal, apical and angular deviation was about half of that reported by Vasak at al. using the NobelGuide system for the rehabilitation of partially edentulous maxillae and mandibles, although all maximal deviations measured in both clinical studies were within the safety margins recommended by the planning software manufacturer⁵⁸ Vasak C, Watzak G, Gahleitner A, Strbac G, Schemper M, Zechner W. Computed tomography-based evaluation of template (NobelGuide™)-guided implant positions: a prospective radiological study.
→ Clin Oral Implants Res. 2011 Oct;22(10):1157–63.

According to a recent systematic review and meta-analysis of computer-assisted, template-based implant surgery for different types of edentulism, the clinician should consider a mean error of 1.12 mm at the entry point and of 1.39 mm at the apex.⁵⁹Tahmaseb A, Wismeijer D, Coucke W, Derksen W. Computer technology applications in surgical implant dentistry: a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:25–42. However, the same report indicates that the clinician should be aware that maximal deviations of 4.5 mm and 7.1 mm, respectively, have been reported—which is clinically relevant.⁶⁰Tahmaseb A, Wismeijer D, Coucke W, Derksen W. Computer technology applications in surgical implant dentistry: a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:25–42. These average deviations are slightly higher than those reported by Fürhauser et al. using stereolithographic templates for the rehabilitation of single-tooth implants in the anterior maxilla (the mean deviation between planned and actual implant position measured 0.84 ± 0.44 mm at the implant shoulder [range of 0.0–1.6 mm] and 1.16 ± 0.69 mm at the implant apex [range of 0.0–2.6 mm]).⁶¹Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27. Mean angular deviation was 2.7 ± 2.6° (range of 0.0–12.7°) and was significantly correlated to apical deviation, but not to inaccuracy at the implant shoulder.

A retrospective study by Ersoy et al. on the 3-D accuracy of nine single-tooth implants placed by guided implant surgery reported a mean error of 0.74 ± 0.40 mm at the implant neck and 1.66 ± 0.28 mm at the apex and an angular deviation of 3.71 ± 0.93°.⁶²Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45. No minimum and maximum deviations were reported for the implant-supported single-tooth restorations. The authors reported a statistically significantly higher accuracy between single and both partially and edentulous patients, in favor of singletooth gap restorations.

A possible explanation of these results was recently published in a systematic review and meta-analysis by Tahmaseb et al., who reported that the tooth-supported guides tended to be slightly more accurate than mucosa- or mucosaand pin-supported guides.⁶³Tahmaseb A, Wismeijer D, Coucke W, Derksen W. Computer technology applications in surgical implant dentistry: a systematic review.
→ Int J Oral Maxillofac Implants. 2014;29 Suppl:25–42. These results are also in accordance with those of the third EAO Consensus Conference on computer-guided implant therapy and soft-and hard-tissue aspects, that tooth and mucosa-supported templates can give more accurate results than bone-supported templates.⁶⁴Sicilia A, Botticelli D, Working Group 3. Computer-guided implant therapy and soft- and hard-tissue aspects. The third EAO Consensus Conference 2012.
→ Clin Oral Implants Res. 2012 Oct;23 Suppl 6:157–61.

Esthetic outcomes of implant-supported single-tooth restorations performed using computer-assisted, template-based surgery

There are no in vivo randomized controlled trials in the literature that report esthetic outcomes of computer-assisted, template-based implant placement compared with free-hand surgery for the treatment of single-tooth gaps. In a prospective study, Fürhauser et al. reported the 3-D accuracy of 27 single-tooth implants placed for delayed replacement of maxillary incisors, using stereolithographic templates.⁶⁵Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27. The esthetic outcomes were evaluated using the PES.39 In this study, the mean deviation between the planned and actual implant position was calculated by superimposition of postoperative CBCT scans, with a mean follow-up of 2.3 years. The authors found that the 3-D inaccuracy is low in guided implant surgery, but that it may significantly compromise the implant esthetics in the anterior maxilla. Particularly, deviations toward the buccal side ≥ 0.8 mm resulted in significantly worse implant esthetics (median PES of 9.5) compared with more accurate implant positions (median PES of 13).⁶⁶Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27. These results confirm the hypothesis that the 3-D implant position has an important influence on the esthetic outcome. A positioning of the implant that is too buccal may result in an increased crown length compared with the contralateral tooth and in midfacial reces sion over time.

Clinical outcomes of implant-supported single-tooth restorations performed using computer-assisted, tempplate-based surgery

There are no in vivo randomized controlled trials in the literature that report the survival or success rates of implants placed using computer-assisted, template-based surgery compared with freehand surgery for the treatment of single-tooth gaps. One randomized controlled trial, and four in vivo prospective studies19, ⁶⁷Pozzi A, Moy PK. Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.
→ Clin Implant Dent Relat Res. 2014 Aug;16(4):582–93.⁶⁸Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23.⁶⁹Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45. ⁷⁰Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. treating single-tooth gaps were identified. In two studies⁷¹ Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27.
⁷²Pozzi A, Moy PK. Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.
→ Clin Implant Dent Relat Res. 2014 Aug;16(4):582–93. NobelClinician Software (Nobel Biocare, Gothenburg, Sweden) was used. In the other three studies, Implant 3D software (med3D, Heidelberg, Germany),⁷³Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23. Stent Cad (Media Lab, La Spezia, Italy),⁷⁴Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45. and iDent software (iDent Imaging, Ft. Lauderdale, Florida, U.S.)⁷⁵Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. were used.

A total of 125 single implants were placed in 123 patients (18–68 years old). In all five studies, no implant failed, resulting in a cumulative survival rate of 100%.⁷⁶ Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27.
⁷⁷Pozzi A, Moy PK. Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.
→ Clin Implant Dent Relat Res. 2014 Aug;16(4):582–93.⁷⁸Behneke A, Burwinkel M, Behneke N. Factors influencing transfer accuracy of cone beam CT-derived template-based implant placement.
→ Clin Oral Implants Res. 2012 Apr;23(4):416–23.
⁷⁹Ersoy AE, Turkyilmaz I, Ozan O, McGlumphy EA. Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.
→ J Periodontol. 2008 Aug;79(8):1339–45.
⁸⁰Farley NE, Kennedy K, McGlumphy EA, Clelland NL. Split-mouth comparison of the accuracy of computergenerated and conventional surgical guides.
→ Int J Oral Maxillofac Implants. 2013 Mar-Apr;28(2):563–72. A mean follow-up period was reported only in two studies,⁸¹Fürhauser R, Mailath-Pokorny G, Haas R, Busenlechner D, Watzek G, Pommer B. Esthetics of flapless single-tooth implants in the anterior maxilla using guided surgery: association of three-dimensional accuracy and Pink Esthetic Score.
→ Clin Implant Dent Relat Res. 2015 Oct;17 Suppl 2:e427–33. Epub 2014 Oct 27.
⁸²Pozzi A, Moy PK. Minimally invasive transcrestal guided sinus lift (TGSL): a clinical prospective proof-of-concept cohort study up to 52 months.
→ Clin Implant Dent Relat Res. 2014 Aug;16(4):582–93. ranging from 12 to 52 months.

Conclusion

Despite the high accuracy and a cumulative survival rate of 100%, there is little evidence to support the hypothesis that there is a clinical advantage of computer-assisted, template-based implant placement over conventional treatment protocols for the placement of an implantsupported
single-tooth restoration.

• Single implants placed using computerassisted, template-based surgery are associated with higher accuracy than single implants placed using a navigation system.
• Tooth-supported templates used to treat cases of partial edentulism provide more accurate results than do mucosa-supported templates used in completely edentulous patients.
• Tooth-supported templates for implantsupported single-tooth restorations provide even more accurate results than those for partially edentulous patients.
• Clinicians should inform patients that computerassisted, template-based surgery implies greater planning time and additional costs. However, the higher cost should be analyzed in terms of cost-effectiveness and in light of the reduction of surgery time and postoperative pain and swelling, as well as the possible increased accuracy.
• The avoidance of critical anatomical structures, as well as the esthetic and functional advantages, with prosthodontically driven implant positioning must also be considered.
• Long-term randomized clinical trials and future reviews of literature on the topic of single-tooth replacement with implants are needed.

Competing interests

This review was performed at the request of the Foundation for Oral Rehabilitation. This foundation is an independent international initiative that unites professionals from various disciplines to improve oral health care and support humanitarian leadership. The study was self-supported and the authors declare no competing interests.

Acknowledgments

The authors highly appreciate the skills and commitment of Prof. Daniel van Steenberghe in the supervision of the study and for his help in correcting the article.

Interview

with Tallarico Marco

Why did you conduct the research reported on in this paper?

This review was performed at the invitation of the Foundation for Oral Rehabilitation, with the aim of evaluating the scientific evidence on accuracy, as well as esthetic and clinical outcomes, of single-tooth implants placed using computer-assisted, template-based surgery.

For what reasons could others cite your paper?

Despite the high accuracy and a cumulative survival rate of 100% reported by some authors, there is still little evidence on guided surgery for single-implant placement. The present critical review included 20 articles on this topic and provides some considerations helpful for further research.

How could your study’s findings have an impact on dentistry?

The findings of this review are both dentistry- and patient-oriented. This surgical approach holds great potential for the daily clinical practice.

What is the relevance of your study’s findings to the daily practice of a dentist?

This review completely supports the use of guided surgery for the rehabilitation of patients requiring single-tooth replacement in the daily practice.

What are your recommendations for further investigation of the topic of your article?

As reported in the conclusion, long-term randomized clinical trials and future reviews of literature on the topic of single-tooth replacement with implants are needed.

Leave a Reply

Be the First to Comment!

Please insert the code above to comment

Manage Subscriptions ∨

None
Notify of new replies to this comment
Notify of new replies to all my comments
Notify of all new follow-up comments

---