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WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 123
DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
Rehabilitation of edentulous mandible with tilted implants
followed by immediate functional loading: A Case Report.
Dr.Naisargi Shah*, Dr. Shweta Annaldasula**, Dr. Sangeeta Yadav***, Dr. Vishrut
Bhatnagar***, Dr. Shruti Gill***, Dr. Shantanu Jambhekar****, Dr. Arshad Idrisi****,
Dr. Prashant Patil****
*Professor & Head, **Post-Graduate Student, ***Reader, ****Lecturer
Dept. of Prosthodontics, Crown and Bridge, Terna Dental College, Nerul, Navi Mumbai.
Introduction:
The presence of atrophied alveolus in the
posterior parts of a completely edentulous
patient poses a major concern while placing
dental implants. The augmentation surgery
conducted for the alveolar atrophy is
associated with higher chances of
complications in the patients. A novel
concept, described initially by Paulo Malo
and his associates in 2003, is the “All-on-
Four” principle. This concept encompasses
the utilization of four implants restored with
straight as well as angled multiunit
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 124
DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
abutments, which support a fixed,
provisional, and instantaneously loaded,
full‑arch prosthesis positioned on the same
day of surgery.1 This treatment option has
been introduced to avoid such unfavorable
posterior regions, by allowing the usage of
tilted implants for an improved spread of the
dental implants, both anteriorly and
posteriorly.2 Some retrospective studies have
been conducted which have shown that “All-
on-Four” principle can have successful
outcomes.3 However, there is a dearth of
Indian scientific evidence with regards to the
outcome of this novel technique in the Indian
patients. Here, we present a case report
showing the successful usage of tilted
implant on similar principles.
Case History:
A 55-year old female came to the Department
of Prosthodontics, Terna dental College,
Nerul, Navi Mumbai with the chief complaint
of replacement of missing teeth. She had a
past medical history of anemia for 2 years,
without a history of any other chronic illness.
She had a history of dental extraction (16, 36,
37, 46) which was done 1 month back. Her
serum calcium report showed a level of 5.98
mg/dl, and she was on a fixed drug
combination (FDC) medication comprising
of vitamin K2, calcium carbonate (elemental
calcium) and calcitriol.
The treatment options which were discussed
for this patient was a set of complete
dentures, Implant supported overdentures or
an implant supported mandibular denture
opposing maxillary complete denture. The
patient opted for placement of implants in
mandible opposing maxillary denture.
After taking the pre-operative photographs
and orthopantomogram (OPG), the teeth
were then extracted completely. Due to the
less dense bone in posterior region, option of
tilted implants was carried out. (Figure 1,2)
The primary and the definitive impressions
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 125
DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
were taken, followed by analysis of the
vertical dimension both at rest and at
occlusion, as well as the Facebow recording.
(Figure 2) The try in and denture fabrication
was completed. The relining and attachment
of the radiographic markers were done before
cone-beam computed tomography (CBCT),
which was then super imposed for accurate
placement of implants. (Figure 4). The Dio-
Navi Implant Planning was done for
fabrication of surgical guide for pre-
determined implant positions. (Figure 5).The
DIO NAVI implant system (Digital Implant
system, India) was used with starter kit with
all the drills from initial to final.
The surgical phase started with the placement
of the surgical guide affixed with screws.
(Figure 5). The tissue punch was then
conducted at the implant site followed by a
bone flattening drill. (Figure 6) The guide
drill was initially done with the help of a
guide tube which acts as a stopper preventing
over-drilling of bone. The protocol from
initial to final drill was followed. (Figure 7)
The abutment profile drill was then
conducted which followed by the placement
of the implants with torque of 50rpm (Figure
8). The surgical guide was then removed
carefully, following which the placement of
the gingival formers was done in regions 42,
32, and 34 along with graft placement in
region 44 (Figure 9)
In the prosthetic phase, the polyvinyl
siloxane impression was made with the
denture to get an accurate position of the
temporary cylinders. These cylinders were
picked up using bisacrylic composite
(Luxatemp, DMG America) and denture was
converted as provisional hybrid prosthesis for
immediate loading. (Figure 10)
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 126
DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
Discussion:
Recently, a shift in the management practices
has been adopted by dentists worldwide to
decrease the costs for treatment with minimal
complications, providing the best outcomes
to the patients. The “All-on-Four” treatment
principle came to the fore keeping these
dental practices in mind, as a treatment
choice for rehabilitation of edentulous
patients with better quality outcomes.4
In this novel treatment concept, the two
posterior implants are placed in front of the
mental foramina at a tilt to avoid any kind of
injury to the inferior alveolar nerve. This
reduces the cantilevers, which allows the
growth of the polygonal area for a completely
fixed prosthesis and gives suitable support to
the molars.5,6
This treatment principle also helps in
improving the primary stability as well as the
cortical anchorage, which helps in the usage
of longer implants.6 It also eliminates the
bone grafts in the edentulous mandible as
well as the maxilla in most cases. Various
studies which are published on this principle
in the western countries have found that the
survival rates of the implants placed using the
“All-on-Four” treatment principle is between
92% to 100%.2,8
In this case, the loading was done
immediately at the end. It has been suggested
that there is early osseointegration of the
immediately loaded implants with enough
strength, on condition that the implant
micromotion and the forces are in control.
However, while performing this technique,
care should be taken about the cantilever
length in the prosthesis, as it cannot exceed a
limit. Also, free-hand random placement of
implants is not possible with this technique as
it is totally driven by prosthesis.
Various approaches have been used till date
in case of patients with completely
edentulous arches. These include the use of
short implants (6 mm in length, 3 mm or even
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 127
DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
less in breadth), guided bone generation,
alveolar distraction osteogenesis, wedge
shaped implants, trans-mandibular staple
implants as well as the use of intra and
extraoral autogenous bone grafts.9
In the year 1990, Dr. Malo clinically
documented via his retrospective study a
method which involves the tilting posterior
implants to improve the anchorage of bone,
to improve the prosthesis support and avoid
bone grafting procedure using “all-on-four
concept”. In this study, 44 patients were
treated and placed with 176 immediately-
loaded implants, positioned in the anterior
region, providing support to fixed complete
arch mandibular prostheses. Five
immediately-loaded implants were lost in
five of the treated patients prior to the 6-
month follow up, amounting to total survival
rates of 96.7 and 98.2% respectively for
development and routine groups. The
prosthesis survival rate was found to be
100%, and the average bone resorption was
extremely low. Thus, Dr. Paulo Malo
developed, standardized and systematically
analyzed the rehabilitation technique of
completely edentulous ridges by “All-On-4
concept”. This concept includes the process
of placing four implants, 2 anteriorly axially
and 2 posteriorly tilted to an angle of 30 to 45
degrees. This implant tilting will enable the
usage of implants with longer length, which
helps in improved cortical engagement as
well as better stability. This also helps in
avoiding the necessity for bone augmentation
procedure, trauma to the anatomical
structures lying underneath, and improved
stress distribution. Following this, a
temporary, fixed and instantly loaded, full-
arch prosthesis is positioned on the same day
of surgery. This will lead to reduction in the
post-operative pain and discomfort to the
treated patient.10
In the year 2007, Zampelis et al. conducted a
study to assess whether tilting of splinted
implants impacts the distribution of stress in
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DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
the bone present around the implant cervix,
and to evaluate whether the usage of tilted
implants like distal abutments is
biomechanically better compared to distal
cantilevers, with the usage of two
dimensional finite element analysis. The
authors mentioned in the limitations that
distal tilting of implants splinted by fixed
restorations does not lead to elevated bone
stress in comparison to the vertical and
normally placed implants. Thus, the authors
proclaimed biomechanical advantage in the
usage of tilted distal implants instead of the
distal cantilever units.11
Computer assisted surgery includes the
incorporation of All-on-four technique and
usage of template made digitally, thus
helping in a more accurate positioning of
distal implants and protection of the vital
anatomical structures like maxillary sinus or
the mandibular nerve. This would help in
obtaining a more expectable implant survival
rate and improved stress distribution by the
prosthesis. Computer assisted surgical guide
is fabricated using the OPG, CBCT scans as
well as casts.12
Thus, in this case, the tilted implant
technique allows:
• Placement of longer implants
which increases implant-to-bone
interface and thus, gives primary
stability to the implants
• A wider distance is created
between the anterior and posterior
implants which results in better
distribution of load and decreased
stress on implants, thereby
increasing the longevity of
prosthesis.
• The need for cantilevers is
eliminated in prosthesis by distal
tilting of implants and the need
for bone augmentation is also
removed.
• The positioning of implants is
more precise, which reduced
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DR. SHAH ET AL: REHABILITATION WITH TILTED IMPLANTS AND IMMEDIATE LOADING
chance of trauma to adjacent
anatomical structures.
Instantaneous loading of
prosthesis, thus decreasing the
post-operative distress to the
patient.
Conclusion:
The tilted implants placement principle is an
able alternative for rehabilitation of
edentulous jaws in comparison to the
advanced surgical methods, sans the use of
removable prosthesis. It is a cost-effective
technique, reduces the treatment period as
well as complications, and gives a better
quality of life to the patient.
References:
1. Thumati P, Reddy M, Mahantshetty
M, Manwani R. "All-On-4/DIEM 2"
A concept to rehabilitate completely
resorbed edentulous arches. J Dent
Implant 2015;5:76-81.
2. Anandh B, Lokesh B, Ebenezer V,
Jimson S, Parthiban J. All on four -
the basics. Biomedical and
Pharmacology Journal. 2015;8:609-
12.
3. Taruna M, Chittaranjan B, Sudheer
N, Tella S, Abusaad M. Prosthodontic
perspective to all-on-4® concept for
dental implants. J Clin Diagn Res.
2014;8(10):ZE16–ZE19.
4. Rangert B, Jemt T, Jörneus L. Forces
and moments on Brånemark implants.
Int J Oral Maxillofac Implants.
1989;4:241-47.
5. Sertgöz A, Güvener S. Finite element
analysis of the effect of cantilever and
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implant length on stress distribution
in an implant-supported fixed
prosthesis. J Prosthet Dent.
1996;76:165-169.
6. Butura CC, Galindo DF, Jensen OT.
Mandibular all-on-four therapy using
angled implants: a three-year clinical
study of 857 implants in 219 jaws.
Oral Maxillofac Surg Clin North Am.
2011;23(2):289-300
7. Hassine MBH, Bucci P, Gasparro R,
Lauro AED, Sammatino G. Safe
approach in “All-on-four” technique:
a case report. Annali di Stomatologia
2014;V(4):142-45.
8. Babbush CA, Kutsko GT, Brokloff J.
The all-on-four immediate function
treatment concept with NobelActive
implants: a retrospective study. J Oral
Implantol. 2011;37(4):431-45.
9. Maló P, de Araújo Nobre M, Lopes
A, Francischone C, Rigolizzo M.
“All-on-4” immediate-function
concept for completely edentulous
maxillae: A clinical report on the
medium (3 years) and long-term (5
years) outcomes. Clin Implant Dent
Relat Res 2012;14 (1):e139-50.
10. Maló P, Rangert B, Nobre M. “All-
on-Four” immediate-function
concept with Brånemark System
implants for completely edentulous
mandibles: A retrospective clinical
study. Clin Implant Dent Relat Res
2003;5(1):2-9.
11. Zampelis A, Rangert B, Heijl L.
Tilting of splinted implants for
improved prosthodontic support: A
two-dimensional finite element
analysis. J Prosthet Dent
2007;97:S35-43.
12. Kan JY, Rungcharassaeng K, Oyama
K. Computer-guided implant
treatment with all-on-four
immediate-function concept.
Contemp Esthet 2007;20-25.
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FIGURE 2. POST EXTRACTION INTRA-ORAL PHOTOGRAPHS
FIGURE 1. PRE-EXTRACTION INTRA-ORAL PHOTOGRAPHS
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 132
FIGURE 3. UPPER AND LOWER PRELIMINARY AND FINAL
IMPRESSIONS FOLLOWED BY FACEBOW
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 133
FIGURE 4. RADIOGRAPHIC MARKERS ATTACHED TO LOWER
DENTURE
FIGURE 5. DIO-NAVI IMPANT PLANNING FOR PLACEMENT OF IMPLANTS IN
32,34,42,44 REGION
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 134
FIGURE 6. PLACEMENT OF SURGICAL GUIDE INTRAORALLY
FIGURE 7. TISSUE PUNCH AND BONE FLATTENING DRILL
FIGURE 8. INITIAL TO FINAL DRILL BEFORE PLACING IMPLANT
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 135
FIGURE 10. SURGICAL GUIDE REMOVED, GINGIVAL FORMERS PLACED, GRAFT AND
PLACEMENT OF MEMBRANE WITH 44 REGION
FIGURE 9. ABUTMENT PROFILE DRILL FOLLOWED BY IMPLANT PLACEMENT
WWW.WJASR.IN VOL. 2 ISSUE 3 MAY – JUNE 2019 136
FIGURE 11 : PROVISIONAL DENTURE CONVERSION PHASE