Evaluation of the Accuracy of NaviDent, a Novel Dynamic Computer-Guided Navigation System for ...

105 Pages·2013·4.19 MB·English

Evaluation of the Accuracy of NaviDent,
a Novel Dynamic Computer-Guided
Navigation System for Placing Dental
Implants

by

Eszter Somogyi-Ganss

A thesis submitted in conformity with the requirements
for the degree of Master of Science
Graduate Department of Prosthodontics
University of Toronto

© Copyright by Dr. Eszter Somogyi-Ganss (2013)
Abstract

Evaluation of the Accuracy of NaviDent, a Novel Dynamic Computer-Guided
Navigation System for Placing Dental Implants

Degree of Master of Science
2013

Eszter Somogyi-Ganss DMD, PhD
Graduate Department of Prosthodontics
University of Toronto

Objectives: To evaluate and compare an experimental surgical navigation system (ESNS) in implant
placement accuracy to static planning and transfer systems. Material and Methods: Partially
edentulous, surgical typodonts were used to simulate prosthetically-driven osteotomies in preclinical
setting. After cbCT acquisition the DICOM files were used to reverse plan and fabricate surgical guides.
Manual placement, three static guiding systems and ESNS were compared. Eight osteotomies per jaw
were transferred to 10 typodonts in five series, resulting in 400 osteotomies by 3 operators, each
modality. Lateral, vertical, total and angular deviations were measured and compared. Results:
Computer-assisted systems were comparable and provided superior precision laterally and in
angulation, but not vertically; implants placed in free-end positions were less accurate. Conclusions: All
computer-aided methods showed less than 2 mm or 5 degrees error on average, which needs to be
considered in clinical practice.
ii
We will either find a way, or make one.
Hannibal

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Acknowledgements

There are several people who contributed to my work on this thesis that I’d like to thank:

 First and foremost my supervisor Dr. Asbjørn Jokstad for his example of relentless
pursuit of truth in science and his help with this work.
 This thesis would not have been the same without the constructive criticism of my two
committee members Dr. Ernest W. N. Lam and Dr. Howard I. Holmes.
 Sincere thanks to my dear colleagues Dr. Brent P. C. L. Winnett and Dr. Waad Kheder,
who (almost) voluntarily disappeared in the dust cloud and helped with the
experimental part.
 Doron Dekel and Arish Quazi for the development of the experimental surgical
navigation system and all the troubleshooting.
 I gratefully acknowledge Charles Victor helping me with statistics.
 Dr. Romeo Paculanan for his help with the initial laboratory steps.
 Slawek Bilko for his help with construction of the surgical guides.
 The very accommodating staff at the Radiology department who were always willing to
take ‘just one more’ cbCT.

This project was supported by: Claron Technology Inc., Toronto, Canada and Nobel Biocare
Research Fellowship, Prosthodontics

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Table of Contents

Abstract ........................................................................................................................................................ ii
Acknowledgements ..................................................................................................................................... iv
List of Tables .............................................................................................................................................. viii
List of Figures .............................................................................................................................................. xi
Introduction ................................................................................................................................................. 1
Significance of implant dentistry .............................................................................................................. 1
Implant-retained prostheses .................................................................................................................... 1
Therapy plan requirements .................................................................................................................. 2
Radiographic diagnostics ...................................................................................................................... 2
Planning implant positions based on diagnostic imaging .................................................................... 6
Operational surgical implant positioning strategies ................................................................................ 7
Historical development of dynamic systems ....................................................................................... 7
Freehand implant placement ............................................................................................................... 8
Laboratory fabricated surgical guides .................................................................................................. 9
Computer-assisted static systems ......................................................................................................10
Surgical guides produced by computerized additive or subtractive manufacturing .........................11
Dynamic computer-assisted dental implant surgery systems ...........................................................13
Accuracy of computer-assisted implant placement in the literature ................................................15
Study rationale ...........................................................................................................................................18
Study objectives .........................................................................................................................................18
Hypothesis ..................................................................................................................................................19
Materials and methods ..............................................................................................................................20
Pre-surgical and surgical preparation ....................................................................................................20
a) Acrylic, laboratory made surgical template ...............................................................................23
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b) Simplant and SurgiGuide ............................................................................................................24
c) Straumann Guided Surgery (coDiagnostiX and gonyX) ..............................................................26
d) NobelGuide surgical template (NobelClinician) .........................................................................29
e) Surgical Experimental Navigation System ..................................................................................31
Accuracy estimation ...............................................................................................................................37
Statistics .................................................................................................................................................41
Results ........................................................................................................................................................42
Power calculations .................................................................................................................................42
Descriptive statistics – Summary of means and standard deviations ....................................................43
Descriptive statistics – Box plots of different outcomes in the mandible .............................................44
Descriptive statistics – Box plots of different outcomes in the maxilla .................................................50
Descriptive statistics – Box plots of different outcomes in both jaws combined ..................................55
Overall statistical comparison of surgical methods ...............................................................................60
Pairwise comparison of methods for different outcomes .....................................................................60
Overall measurements .......................................................................................................................60
Jaw type ..............................................................................................................................................64
Typodont jaw models .........................................................................................................................64
P-values for pairwise comparisons of models for different outcomes ..................................................65
Overall comparison of osteotomy positions for different outcomes ....................................................68
P-values for pairwise comparisons of teeth for different outcomes in the mandible ...........................69
P-values for pairwise comparisons of teeth for different outcomes in the maxilla ..............................73
Intra- and inter-rater agreement ...........................................................................................................75
Discussion ...................................................................................................................................................76
Image processing....................................................................................................................................76
Virtual planning ......................................................................................................................................77
Technical fabrication of a surgical stent ................................................................................................77
Surgery ...................................................................................................................................................78
vi
Clinical relevance....................................................................................................................................82
Summary ....................................................................................................................................................85
Conclusions ................................................................................................................................................86
References ..................................................................................................................................................87

vii
List of Tables

Table 1. Effective dose from dental imaging techniques (µSv) .................................................................... 3
Table 2. Advantages and limitations of cone beam computed tomography ............................................... 6
Table 3. Commercially available implant planning softwares ....................................................................11
Table 4. Possible errors in computer-assisted dental implant placement surgery ....................................13
Table 5. Technology used in commercial computer-assisted implant placement tools ............................15
Table 6. Accuracy data for computer-assisted implant planning and placement .....................................16
Table 7. Accuracy data for computer-assisted implant planning and placement (continued) ..................17
Table 8. Lateral deviation of entry and apex (Figure 22 A and B) ..............................................................43
Table 9. Vertical deviation of apex (Figure 22 C) .......................................................................................43
Table 10. Total deviation of apex (Figure 22 D) .........................................................................................43
Table 11. Angular deviation of apex (Figure 22 E) .....................................................................................44
Table 12. Box plots of total deviation of apex in the mandible (Figure 22 E) ............................................45
Table 13. Box plots of vertical deviation of apex in the mandible (Figure 22 C) .......................................46
Table 14. Box plots of lateral deviation of apex in the mandible (Figure 22 B) .........................................47
Table 15. Box plots of lateral deviation of entry in the mandible (Figure 22 A) ........................................48
Table 16. Box plots of angular deviation of apex in the mandible (Figure 22 D) .......................................49
Table 17. Box plots of total deviation of apex in the maxilla (Figure 22 E) ................................................50
Table 18. Box plots of vertical deviation of the apex in the maxilla (Figure 22 C) .....................................51
Table 19. Box plots of lateral deviation of apex in the maxilla (Figure 22 B) .............................................52
Table 20. Box plots of lateral deviation of entry in the maxilla (Figure 22 A) ............................................53
Table 21. Box plots of angular deviation of apex in the maxilla (Figure 22 D) ...........................................54
Table 22. Box plots of total deviation of apex in both jaws combined (Figure 22 E) .................................55
Table 23. Vertical deviation of apex in both jaws combined (Figure 22 C) ................................................56
Table 24. Lateral deviation of apex in both jaws combined (Figure 22 B) .................................................57
Table 25. Lateral deviation of entry in both jaws combined (Figure 22 A) ................................................58
Table 26. Angular deviation of apex in both jaws combined (Figure 22 D) ...............................................59
Table 27. Overall comparison of surgical methods ....................................................................................60
Table 28. Pairwise comparison of methods for total deviation of apex (difference in mm) .....................61
Table 29. Pairwise comparison of methods for lateral deviation of apex (difference in mm) ..................61
Table 30. Pairwise comparison of methods for vertical deviation of apex (difference in mm) .................62
Table 31. Pairwise comparison of methods for lateral deviation of entry (difference in mm) .................63
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Table 32. Pairwise comparison of methods for angular deviation of apex (difference in degrees) ..........63
Table 33. Comparison of outcomes between jaw types (mm and degree) ...............................................64
Table 34. Overall comparison of five slave typodont models (mm and degree) .......................................64
Table 35. P-values for pairwise comparisons of models for total deviation of apex (difference in mm) ..65
Table 36. P-values for pairwise comparisons of models for lateral deviation of apex (difference in mm)
....................................................................................................................................................................65
Table 37. P-values for pairwise comparisons of models for vertical deviation of apex (difference in mm)
....................................................................................................................................................................66
Table 38. P-values for pairwise comparisons of models for lateral deviation of entry (difference in mm)
....................................................................................................................................................................66
Table 39. P-values for pairwise comparisons of models for angular deviation of apex (difference in
degrees) ......................................................................................................................................................67
Table 40. Overall comparison of osteotomy positions in the mandible for different outcomes (mm and
degree) .......................................................................................................................................................68
Table 41 P-values for pairwise comparisons of teeth for total deviation of apex in the mandible
(differences in mm) ....................................................................................................................................69
Table 42. P-values for pairwise comparisons of teeth for lateral deviation of apex in the mandible
(differences in mm) ....................................................................................................................................70
Table 43. P-values for pairwise comparisons of teeth for vertical deviation of apex in the mandible
(differences in mm) ....................................................................................................................................70
Table 44. P-values for pairwise comparisons of teeth for lateral deviation of entry in the mandible
(differences in mm) ....................................................................................................................................71
Table 45. P-values for pairwise comparisons of teeth for angular deviation of apex in the mandible
(differences in degrees) .............................................................................................................................71
Table 46. Overall comparison of osteotomy positions by tooth number in the maxilla for different
outcomes (mm and degree) .......................................................................................................................72
Table 47. P-values for pairwise comparisons of teeth for total deviation of apex in the maxilla
(differences in mm) ....................................................................................................................................73
Table 48. P-values for pairwise comparisons of teeth for lateral deviation of apex in the maxilla
(differences in mm) ....................................................................................................................................73
Table 49. P-values for pairwise comparisons of teeth for vertical deviation of apex in the maxilla
(differences in mm) ....................................................................................................................................74
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Table 50. P-values for pairwise comparisons of teeth for lateral deviation of entry in the maxilla
(differences in mm) ....................................................................................................................................74
Table 51. P-values for pairwise comparisons of teeth for angular deviation of apex in the maxilla
(differences in degrees) .............................................................................................................................75
Table 52. Intra- and inter-rater agreement................................................................................................75

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