Amr Hosny Elkhadem, DDS, MSc Lecturer, Prosthodontics, Faculty of Oral & Dental medicine, Cairo University The keyless partial guidance using the simple guide kit and c-shaped sleeves is a promising economic alternative to conventional guided approach. Further investigations are required to evaluate its accuracy and long term success rates. www.SimpleGuideSystem.com

1. Elkhadem et al
Background: to describe the con-
cept and use of a simplified keyless
guided implant placement system in
partially and completely edentulous patients.
Methods: 89 implants were placed in 23
patients (7 complete, and 16 partial cases)
using the universal simple guide kit. After
CBCT and virtual implant planning, surgi-
cal guides with c-shaped sleeves were con-
structed. The implants were placed using flap
or flapless approach according to the need
for soft or hard tissue augmentation. The intra-
operative complications, post-operative com-
plains and implant survival rate were reported.
Results: All implants demonstrated insertion
torque values greater than 30 Ncm. Only few
post- operative complications were reported.
98.9% of the placed implants integrated.
Conclusions: The keyless partial guid-
ance using the simple guide kit and c-shaped
sleeves is a promising economic alterna-
tive to conventional guided approach. Fur-
ther investigations are required to evaluate
its accuracy and long term success rates.
The Keyless Partially Guided Implant
Placement Protocol: Success Rate
and Complications
Amr Hosny Elkhadem, DDS, MSc1
1. Lecturer, Prosthodontics, Faculty of Oral & Dental medicine, Cairo University
Abstract
KEY WORDS: Computer-aided Implantology, surgical guide, open sleeve, tolerance
The Journal of Implant & Advanced Clinical Dentistry • 25

2. 26 • Vol. 7, No. 8 • October 2015
INTRODUCTION
The use of CT scans combined with computer
software to plan implant cases has been pro-
posed since the 1990s.1
The technique aims
to provide correlation between the bone anat-
omy and the desired tooth position allowing
for predictable aesthetic and functional out-
comes. Many authors refer to guided implant
placement as a protocol that enhances the
accuracy and safety of implant placement.2-4
Moreover, it allows for the minimally invasive
flapless technique in many situations, which
minimizes the intra-operative time, postopera-
tive pain and postoperative complications.4,5
Despite of the aforementioned advan-
tages the techniques is not popular among
implant practitioners. This might be attributed
to the higher cost and time required to plan
the cases and fabricate the guides. Expensive
guided implant kits with complex assortment
are also mandatory.6
Additionally, the control
over implant direction is usually achieved with
a closed circular configuration with small drill
tolerance. Using the relatively longer drills for
guided systems through such closed configu-
ration was always associated with accessibil-
ity problems in the posterior region for dentate
patients. Such a small tolerance is manda-
tory to provide accuracy, yet it is thought to
block the passage of the irrigation and might
cause increased incidence of implant fail-
ure in dense bone and deep osteotomies7
Moreover, there is an uprising question
related to the accuracy imposed by the mechan-
ical tolerance of the machined components. To
provide adequate precision of the guided sys-
tems, a small gap of approximately 20 microns
is provided between the main sleeve fixed in
the guide and the removable, diameter spe-
cific, keys. A similar tolerance gap is designed
between the removable keys and the drills. The
friction during repeated use of the keys and
the drills increases the gap obviously which
might contribute to increases linear and angu-
lar deviation with these guided systems.8,9
When weighing the merits and demer-
Figure 1: The simple guide kit. (a) cortical drill, (b) 2.3 mm
starter drill, (c,d,e) 2.2 mm pilot drill with variable lengths,
(f) 2.8 mm intermediate drill.
Figure 2: Surgical guide with c-shaped sleeve establishing
3 mm facial openings for side approach of the drills.
Elkhadem et al

3. The Journal of Implant & Advanced Clinical Dentistry • 27
its of conventional guided systems one can
understand why such protocol is not so pop-
ular. Hence, there is a great need to pro-
vide modification in the concept and design
of guided surgical approach to overcome
the drawbacks and maximize the benefits.
MATERIALS AND METHODS
The technique utilizes a simplified universal kit
design (Simple guide kit, Dentis Co.-Ltd, Daegu,
South Korea) and a modified C-shaped main
sleeve. The kit design eliminates the removable
keys used in conventional guided kits, and adopt
the concept of guidance for the pilot and inter-
mediate drills only. For all cases, the final drill-
ing is done after removing the surgical guide
using the conventional non-guided final drills.
The design and sequence of the simplified
kit is different from the regular guided implant
drills (Fig 1). All drills are composed of cutting
flutes and a smooth guiding shaft that is com-
patible in size with the main sleeve of the surgi-
cal guide with no removable key in between. The
drilling sequences starts with a pointed drill for
penetration of the cortical bone. A starter drill
(2.3x8mm) is used to create an initial osteotomy
inside the bone. This is followed by the use of
pilot drills (2.2mm in diameter). The pilot drills
have variable lengths according to the desired
implant to be placed. As the pilot drill diameter is
smaller than the initial osteotomy created by the
starter drill, it will snap into the osteotomy engag-
ing 8 mm of vertical bone height and part of its
guiding shaft will engage the main sleeve of the
guide. In all scenarios, a 2.8x8mm intermediate
drill is used afterwards to prepare the coronal
Figure 3: Virtual implant planning for an edentulous case. Implants were placed in relation to the required prosthetic
position guided by the radio-opaque scan appliance.
Elkhadem et al

4. 28 • Vol. 7, No. 8 • October 2015
8 mm of the osteotomy. As the osteotomy path
is shaped the surgical guide is removed and the
final drill of the conventional kit is used to cre-
ate the final osteotomy shape. This is followed
by inserting the implant in the conventional non
guided fashion. Additionally, the surgical guide
is designed with a c-shaped metal sleeve with a
facial opening (Fig 2). The opening allows for side
approach of the drills and unrestricted access of
the coolant. In this report, 23 cases were oper-
ated. 89 implants were installed in 7 completely
edentulous and 16 partially edentulous cases.
COMPLETELY
EDENTULOUS CASES
37 implants were installed in 7 completely
edentulous cases (two mandibular and 5 max-
illary) using this technique. Preparation started
by duplicating the patient denture into radio-
opaque scan appliance (Barium sulphate to
acrylic resin 1:4). Holes were prepared in the
tooth centre of the proposed site to facilitate its
identification on the CT scan. Double scan tech-
nique was performed. The first scan was done
with the patient wearing the scan appliance
and biting on cotton rolls allowing for teeth
separation. The second scan was made for
the scan appliance alone. Virtual planning was
performed using Blue sky Plan (Bluesky Bio,
LLD – USA). The virtual implants were placed
in the required anatomical sites after correlat-
ing them to the desired tooth positions (Fig 3).
3D superimposition of the scan appliance was
done over the patient CT scan using a point
registration technique (Fig 4). After defining
the diameter, height and offset of the guiding
tubes the software generated the virtual guide
by binding the scan appliance to the guiding
Figure 4: Point registration of the scan appliance over the patient scan. Several points are selected to minimize the
superimposition errors.
Elkhadem et al

5. The Journal of Implant & Advanced Clinical Dentistry • 29
tubes. The STL file of the guide was fabricated
using additive manufacturing. C-shaped sleeves
were fixed in the surgical guide and the guid-
ing tubes were opened facially opposite to the
sleeve openings (Fig 2). The guide was fixed
in the patient mouth with 3 fixation screws and
the suggested drilling sequence was applied.
PARTIALLY
EDENTULOUS CASES
52 implants in 16 partially edentulous cases
(7 mandibular and 9 maxillary) were placed.
Patient scanning protocol differed according to
the number of missing teeth and the presence
of metallic restorations. In cases with few miss-
ing teeth and few or no metallic restoration, the
patient received a CBCT with no scan appli-
ance. The patient model was scanned using a
laser scanner. When the patient had multiple
missing teeth and /or numerous metallic resto-
rations a scan appliance with radiopaque mark-
ers was first prepared. The patient had a CBCT
wearing the scan appliance. Afterwards, a
CBCT for the patient model with the scan appli-
ance was made for superimposition purposes.
Virtual planning was done after correlating the
prosthetic position to the underlying bone anat-
omy. When no scan appliance existed virtual
tooth setting was utilized. When designing the
guide, extension over the adjacent teeth as well
as part of the palatal and lingual mucosa was
required to assure proper stability. All cases not
requiring grafting were done in a flapless man-
ner (Fig 5). In cases requiring bone grafting a
flap was first raised and the guide was then
used for implant placement (Fig 6). When extra
security was required to fix the guide in place
light-cured flowable composite was used to tem-
porarily bond the guide to the supporting teeth.
RESULTS
No major intra-operative complications or
problems were reported in either flap or flap-
less cases. In few cases the c-shaped sleeves
were detached off the guide when contact-
ing the drills. The sleeves were replaced and
the procedure completed. All implants dem-
onstrated acceptable implant stability at inser-
Figure 5: A bilateral flapless maxillary case. Plan was made to avoid enlarged sinus on the left side (a). The guide design
allowed implant placement at the tuberosity region (b).
Elkhadem et al

6. 30 • Vol. 7, No. 8 • October 2015
Figure 6: An anterior maxillary case with labial bone deficiency. The guide was placed after flap elevation to guide ideal
implant drilling (a), which was followed by GBR procedures (b).
tion (more than 30 Ncm). There was no reports
of postoperative infections among all partici-
pants. Only 4 patients reported postoperative
pain that lasted more than one week after the
surgery. The rest of the patients reported no
postoperative pain or mild pain for few days.
Only two case (one flap and one flapless)
reported transient post-operative oedema. At
the second stage, only one maxillary implant
failed with overall success rate of 98.9%.
DISCUSSION
The keyless partially guided technique seems
to offer numerous advantages. First, the elimi-
nation of the removable keys together with the
open shaped sleeves allowed for better acces-
sibility during surgery especially in the poste-
rior region up to the maxillary tuberosity. The
open guiding sleeves allowed also for unre-
stricted access of the irrigation during drilling.
The proposed simplified approach did not
compromise the control over osteotomy prep-
aration at all stages of drilling. The use of a
short starter (2.3x8mm) drill created an ini-
tial osteotomy channel that accommodated
the smaller pilot drill. This assured dual guid-
ance of the pilot drill by engaging the initial
osteotomy apically and the guiding sleeve cor-
onally. The path created by the pilot and inter-
mediate drill is so definite that it guides further
drilling with minor possibilities of introduce
a change in the osteotomy direction or depth.
Final drills with blunt non cutting tip are usu-
ally preferred because they seem to be safer.
By eliminating the removable keys only
one mechanical tolerance is present instead
of the two gaps in the conventional guided
approaches. Theoretically, this will reduce the
mechanical tolerance error to the half. Minimiz-
ing the error introduced by the bur sleeve gap
is thought to be a crucial factor in reducing the
intrinsic errors imposed by guided surgery 8-9
As the majority of cases were flapless, the
incidence of post-operative pain and compli-
cations were less.10-11
As the guide are based
on 3D implant planning on CBCT, direct expo-
Elkhadem et al

7. The Journal of Implant & Advanced Clinical Dentistry • 31
sure of bone was not utilized unless soft
and / or hard tissue augmentation was required.
Moreover, conservative transmucosal drill-
ing was used. Tissue punch was not used
as there is no proven clinical advantage or
impact on the implant success rate when com-
pared to transmucosal drilling. On the con-
trary, the increase in the size of the punched
tissue is thought to increase the probing
depth and crestal bone loss around implants.12
A debate exist about the accuracy of partial
guidance in comparison to classical fully guided
systems. While some practitioners might believe
that guided final drilling and insertion signifi-
cantly affect the accuracy others believe that
guidance of the initial osteotomy provides suf-
ficient guidance to the rest of the procedures.
The clinical data regarding the survival rate
and accuracy of partial versus full guidance is
still sparse.13
Kuhl et al.14
evaluated the accu-
racy of half versus fully guided techniques on
cadaver model. They found no statistical sig-
nificant difference between the two protocols.
Yet, there is a need to conduct more clinical tri-
als to evaluate the accuracy of both systems.
CONCLUSION
The use of the simplified partially guided key-
less approach seems to be a promising alter-
native to conventional guided surgery. The
technique allowed easy access to the poste-
rior region with efficient delivery of the irriga-
tion during drilling. The use of a small economic
universal kit might encourage many practitio-
ners to utilize guided surgery. Further stud-
ies are required to compare the accuracy
and success rate versus the conventional
guided techniques and manual techniques. ●
Correspondence:
Dr. Amr Hosny Elkhadem
e-mail: amrelkhadem@gmail.com
Address: 5 jasmine buildings zahraa elmaadi-
Cairo – Egypt
Postal code: 11435
Disclosure
The author reports no conflicts of interest with anything mentioned in this article.
References
1. Verstreken K, Van Cleynenbreugel J, Martens K, Marchal G, van Steenberghe
D, Suetens P. An image-guided planning system for endosseous oral implants.
IEEE Trans Med Imaging 1998;17(5):842-852.
2. Rosenfeld AL, Mandelaris GA, Tardieu PB. Prosthetically directed implant
placement using computer software to ensure precise placement and
predictable prosthetic outcomes. Part 1: diagnostics, imaging, and collaborative
accountability. Int J Periodontics Restorative Dent 2006;26(3):215-221.
3. Rosenfeld AL, Mandelaris GA, Tardieu PB. Prosthetically directed implant
placement using computer software to ensure precise placement and
predictable prosthetic outcomes. Part 2: rapid-prototype medical modeling and
stereolithographic drilling guides requiring bone exposure. Int J Periodontics
Restorative Dent 2006;26(4):347-353.
4. Rosenfeld AL, Mandelaris GA, Tardieu PB. Prosthetically directed implant
placement using computer software to ensure precise placement and
predictable prosthetic outcomes. Part 3: stereolithographic drilling guides
that do not require bone exposure and the immediate delivery of teeth.
Int J Periodontics Restorative Dent 2006;26(5):493-499.
5. van Steenberghe D, Glauser R, Blomback U, Andersson M, Schutyser F,
Pettersson A, et al. 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;7 Suppl 1:S111-120.
6. Vercruyssen M, Hultin M, Van Assche N, Svensson K, Naert I, Quirynen M.
Guided surgery: accuracy and efficacy. Periodontol 2000. 2014;66(1):
228-246.
7. Yong LT, Moy PK. Complications of computer-aided-design/computer-aided-
machining-guided (NobelGuide) surgical implant placement: an evaluation of
early clinical results. Clin Implant Dent Relat Res. 2008;10(3):123-127.
8. Cassetta M, Di Mambro A, Di Giorgio G, Stefanelli LV, Barbato E. The Influence
of the Tolerance between Mechanical Components on the Accuracy of Implants
Inserted with a Stereolithographic Surgical Guide: A Retrospective Clinical
Study. Clin Implant Dent Relat Res. 2015;17(3):580-588.
9. Cassetta M, Di Mambro A, Giansanti M, Stefanelli LV, Cavallini C. The intrinsic
error of a stereolithographic surgical template in implant guided surgery.
Int J Oral Maxillofac Surg. 2013;42(2):264-75.
10.Hultin M1, Svensson KG, Trulsson M. Clinical advantages of computer-guided
implant placement: a systematic review. Clin Oral Implants Res. 2012;23 Suppl
6:124-35.
11. Brodala N. Flapless surgery and its effect on dental implant outcomes.
Int J Oral Maxillofac Implants 2009;24 Suppl:118-25.
12. Lee DH, Choi BH, Jeong SM, Xuan F, Kim HR, Mo DY. Effects of soft tissue
punch size on the healing of peri-implant tissue in flapless implant surgery. Oral
Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;109(4):525-30.
13. Van Assche N, Vercruyssen M, Coucke W, Teughels W, Jacobs R, Quirynen
M. Accuracy of computer-aided implant placement. Clin Oral Implants
Res. 2012;23 Suppl 6:112-23
14. Kühl S, Zürcher S, Mahid T, Müller-Gerbl M, Filippi A, Cattin P. Accuracy
of full guided vs. half-guided implant surgery. Clin Oral Implants
Res. 2013;24(7):763-9.
Elkhadem et al