IOSR Journal of Dental and Medical Sciences (IOSR-JDMS)

e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 23, Issue 6 Ser. 6 (June. 2024), PP 50-55
www.iosrjournals.org

Implant Retained Silicone Finger Prosthesis With

Customized Abutment And A Telescopic Attachment: A
Case Report.
Dr. Harsha Kumar K, Dr. Nissy Chacko, Dr. Kartik Kapoor, Dr. Shony Mohan
(Hod, Department Of Prosthodontics, Government Dental College, Thiruvananthapuram, India)
(Mds Pg Student Department Of Prosthodontics, Government Dental College, Thiruvananthapuram, India)
(Consultant Prosthodontist And Implantologist, Mp Dental Council, Madhya Pradesh, India)
(Assistant Professor, Department Of Prosthodontics, Government Dental College, Thiruvananthapuram, India)

Abstract:
Traumatic finger amputations are the most commonly encountered forms of partial hand loss. The prosthetic
rehabilitation of an amputated finger is considered when micro-surgical reconstruction is contraindicated,
unaffordable or failed. An aesthetic and functional prosthesis can offer distinct psychological and rehabilitative
advantages to the patient. This article presents rehabilitation of a young male patient with amputated right ring
finger by fabrication of an aesthetic silicone finger prosthesis retained by a dental implant, osseointegrated over
a period of four months. The type of attachment was a custom designed ball abutment attached to a telescopic
housing carrying an O-ring. An antirotation notch was incorporated to achieve stability. The prosthesis provided
functionality such as counter support while writing and grasping objects. The aesthetic outcome and customized
color met the patient's desire for inconspicuousness.
Keywords: Abutment Design; Amputation; Dental Implant; Finger Prosthesis; Surgical Flap
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Date of Submission: 07-06-2024 Date of Acceptance: 17-06-2024
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I. Introduction
Fingers as organs of manipulation have an indispensable role in function and aesthetics. The wide range
of hand movements and functions are apparent from its position, movements and actions. The active function of
the hand is represented by its prehensile activities in grip, grasp and transferring, and absorbing forces. Hands
also have an aesthetic impact as they can emphasize the beauty of a gesture or the grace of a movement. 1–3 Hands
can be affected by an umpteen number of conditions such as congenital malformations and systemic diseases
(diabetes mellitus), but traumatic amputations continue to be the most common cause leading to partial or total
digit loss.3–5 Amputation of finger causes devastating physical, psychosocial and economic damage to an
individual. The feeling of physical impairment can bring apathy towards life due to the social stigma. Thus, the
artificial substitutes play an immense role in making the patient more socially acceptable.4,5 Many surgical and
microsurgical replantation techniques are available and used to save severely injured and traumatically amputated
fingers. However, such reconstructions are either contraindicated or unsuccessful. Hence, it is in this group of
patients that an aesthetic and functional prosthesis can be of great help. 1
Standard finger prosthesis is retained by a vacuum effect on the stump. Prosthetic replacement of the
fingers can be satisfactory in patients who have at least 1.5cm of residual stump. However, patients performing
more vigorous activities like swimming, knitting, gardening, cooking are often concerned about retention
and fear of detachment leading to public embarrassment. As retention is the primary determinant factor in the
success of prosthesis, osseointegrated digit prosthesis presents a viable and affirmative treatment modality to
rehabilitate patients with finger amputations.1,6
The implant supported finger prosthesis is securely attached by means of an implant placed inside the
intramedullary canal of residual bone, by a phenomenon known as “osseointegration” which is defined as a direct
structural and functional connection between ordered , living bone and surface of a load carrying implant. 7
Osseointegrated extraoral implants are a reliable alternative in the management of orbital, ear, and nose defects
and the success has revolutionized the field of implant supported maxillofacial prosthesis. 1,8
Furthermore, the osseointegrated finger prosthesis provide some degree of tactile sensation and this
special concept where osseointegrated fixtures identify tactile thresholds transmitted through their prostheses is
well documented as “osseoperception”.9,10 This clinical case report describes the fabrication of silicone finger
prosthesis secured by using dental implants with customized abutments to rehabilitate a young male patient
presented with a traumatic amputation of right ring finger. Also, the patient is a navy crew member
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 Implant Retained Silicone Finger Prosthesis With Customized Abutment And A Telescopic………

involved in various vigorous activities like swimming which makes the need for osseointegrated prosthesis even
more desirable.

II. Clinical Report

A 25- y ear- o ld male patient presented with a traumatic amputation of his right ring finger, which he
had lost in a road traffic accident 3 months before and desired rehabilitation of the same. The traumatic
amputation was at the level of middle of intermediate phalanx along with moderate soft tissue loss (Figure 1).
After removal of the gangrenous part, the underlying phalanx was exposed. It was covered using neurocutaneous
Litler flap harvested from medial surface of middle finger. All the joints apart from one which is injured were
tested for mobility, tendon repair and physiotherapy was undertaken before further procedures. Upon complete
healing the affected hand was radiographically evaluated. As the length of the remaining stump was 15mm and
the width of the inner cortex was 5mm an Implant retained finger prosthesis was planned (Figure 1).
Stage I surgical phase was done under complete aseptic protocol. After administering a wrist block, a
local flap was raised, tissue dissection was done and a bone exposure of around 4mm was obtained from all
sides. The initial osteotomy was begun with a pilot drill of 2mm followed by sequential drilling. Final
osteotomy site was prepared using bone expander and special thumb screws (Figure 2). An intraoral implant
(ADIN Dental Implant Systems Ltd, Touareg™-OS ) of dimension 3.3mm x 10 mm was placed longitudinally
into the medullary canal, cover screw was placed, the surgical site was sutured and surgical dressing was given.
Implant was left unloaded for four months to allow for osseointegration (Figure 3). At stage II, the
healing cap was placed with a flapless procedure (Figure 4) and 3 week time was given for the formation of
tissue collar around healing cap (Figure 4). A special tray was fabricated for an open tray impression procedure.
Impression post was screwed onto the implant fixture (Figure 5) and impression was made using a double
mix technique with light and medium bodied pol vinyl siloxane impression material (Aquasil, Dentsply, India).
Once the material got polymerized the impression was carefully retrieved and laboratory analogue was attached
(Figure 6). The impression was poured in ADA type IV dental stone (Elite Master, Zhermack) to produce the
final cast.
Since the prefabricated ball attachments would have cause rotational effect thus putting the stability of
finger prostheses into jeopardy, special customized attachments were designed to gain frictional fit as well as
to achieve maximum stability. The technique of fabrication was similar to that used to fabricate implant
superstructure and telescopic attachments. In the present case, plastic caps were used as wax patterns and
cast using cobalt-chromium alloys. The male component in the attachment assembly was a customised ball
attachment with an antirotation notch (Figure 7) whereas the female component is a telescopic attachment with
an O-ring in its inner surface and multiple small beadings on the outer surface to achieve mechanical retention
for the superstructure (Figure 7). The attachments were tried onto the implant fixture to check for precise fit
and proper orientation similar to that in the cast. An acrylic superstructure was made onto the female
component from autopolymerizing acrylic resin (Lucitone Fas-Por+ Liquid, Dentsply, International).
Impression was made of the unaffected contra lateral hand with irreversible hydrocolloid impression
material (Neocolloid, Zhermack) and wax was poured into the moulds to obtain wax pattern. The wax pattern
was tried onto the finger as well as on the cast. The, size, shape and contours were evaluated. The details of nail
bed and joint knuckles were sculptured in the wax pattern. The nail was then made from autopolymerizing
resin and extrinsic staining was done for better aesthetics. It was later trimmed, polished and checked onto
the wax pattern. Wax pattern with the cast was then invested and stone mould was fabricated using the lost wax
technique.
The acrylic resin superstructure was cleaned and silicone bonding primer was applied. The silicone
material (RTV KIT, Factor II) was mixed in correct base and catalyst proportions and appropriate intrinsic
colours were incorporated to simulate every detail and it was then layered onto the mould using brush of
sequential sizes. The mould was filled with the mix, tightened gently and cured overnight for the polymerization
to be completed. The finger prosthesis was then retrieved, trimmed and polished. The nail was attached with
primer and the complete finger prostheses was tried and checked for proper fit and aesthetics (Figure 8 and
9). The function was evaluated for holding, writing and grasping positions. The prosthesis was functionally
effective, aesthetically pleasing and satisfactory retention was also attained. Patient was instructed for proper
home care use for the maintenance of the prosthesis. Upon review after one week, it was revealed that due
to the vacuum fit of the prosthesis an anaerobic infection has developed. As a remedial measure Metrogyl
ointment was prescribed. Appropriate post insertion instructions such as frequent prosthesis removal and
lubrication were given to the patient, the issue resolved in a period of one week.
After 3 months of follow up the healing was found to be satisfactory and no tissue reaction was
observed on the skin around the implant.

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 Implant Retained Silicone Finger Prosthesis With Customized Abutment And A Telescopic………

III. Discussion
According to Pilley M.J, when surgical reconstruction of lost finger is contraindicated, unsuccessful
or unavailable, prosthesis can provide and offer great psychological help. A precisely fitting prosthesis can
improve function by restoring normal length, providing opposition for the remaining digits, maintaining
sensitivity through a thin lamina, protecting a sensitive stump, and transmitting pressure and position sense for
activities such as writing or typing 1,2.
Retention in finger prosthesis is generally achieved by a vacuum effect on the stump, use of medical
grade adhesives, and placement of finger ring. Recently, osseointegrated implants are used to retain the finger
prostheses. In the suction- fitted prosthesis, the elastic and nonporous silicone rubber allows an airtight
“cupping” of the residuum such that an incipient slippage of the prosthesis is immediately followed by an
internal vacuum effect that checks further displacement.1,11,12
Buckner H et al, stated that the acceptance rate of individually sculpted custom-made silicone
prosthesis has been much higher.13 The artificial digit is made of a silicone elastomer .These silicones can be
rendered to match the skin colour of the patient and give a more lifelike appearance. Most of silicones used for
this purpose are Room Temperature Vulcanizing Silicones (RTV) as they offer chemical inertness, flexibility
and elasticity.14
The implant retained finger prosthesis offers several benefits over conventional prosthesis such as better
control over prosthesis, weightless feeling, no perspiration, pain and tissue breakdown from the socket, partial
recovery of tactile sensation by transferring stimuli to the bone through implant because of direct pressure of
implant on the bone and most importantly an enhanced retention giving psychological support to the patient.
While the disadvantages of osseointegrated prosthesis are additional surgical procedure, relatively long
rehabilitation period and a risk of anaerobic infection.15 The psychological and functional effects of the
prosthesis enhance rehabilitation by helping patients to adjust to their loss and by permitting more normal
professional life.2

IV. Conclusion
With the ever-advancing technology and revolutionary innovations, the prosthetic rehabilitation of
amputated finger has become successful over complex surgical procedures. This article presents a case report
where a young male patient who presented with a traumatic amputation of right ring finger is rehabilitated with
an implant retained silicone finger prosthesis with customised attachment. The prosthesis was very cost effective
and offered satisfactory retention and stability with well healed peri-implant skin. It also restored near normal
function and overall aesthetic appearance of the patient.

Protocol we put forward is:

1. Step 1: Wound debridement
2. Step 2: Neurocutaneous flap to improve sensation, tendon reconstruction and joint surgery followed by
Physiotherapy.
3. Step 3: Implant placement
4. Step 4: Prosthetic phase
5. Step 5: Follow up

V. limitations
The primary limitation surfaced was the development of the anaerobic infection around the implant.
Secondary limitation is that the protocol followed is on the pilot case only, but we intend to extend our study
enrolling 20-25 patients with 2 year follow up.

references
[1]. Aydin C, Karakoca S, Yilmaz H. Implant-Retained Digital Prostheses With Custom-Designed Attachments: A Clinical Report. J
Prosthet Dent. 2007 Apr 1;97(4):191–5.
[2]. Pillet J. Esthetic Hand Prostheses. J Hand Surg. 1983 Sep;8(5 Pt 2):778–81.
[3]. Pereira Bp, Kour Ak, Leow El, Pho Rw. Benefits And Use Of Digital Prostheses. J Hand Surg. 1996 Mar;21(2):222–8.
[4]. Kini Ay, Byakod Pp, Angadi Gs, Pai U, Bhandari Aj. Comprehensive Prosthetic Rehabilitation Of A Patient With Partial Finger
Amputations Using Silicone Biomaterial: A Technical Note. Prosthet Orthot Int. 2010 Dec;34(4):488–94.
[5]. Mckinstry Re. Fundamentals Of Facial Prosthetics. St Petersburg Abi Prof Publ. 1995 Jan 1;1:181–92.
[6]. Lundborg G, Brånemark Pi, Rosén B. Osseointegrated Thumb Prostheses: A Concept For Fixation Of Digit Prosthetic Devices. J
Hand Surg. 1996 Mar;21(2):216–21.
[7]. Ismail Jy, Zaki Hs. Osseointegration In Maxillofacial Prosthetics. Dent Clin North Am. 1990 Apr;34(2):327–41.
[8]. Scolozzi P, Jaques B. Treatment Of Midfacial Defects Using Prostheses Supported By Iti Dental Implants. Plast Reconstr Surg. 2004
Nov;114(6):1395–404.
[9]. Aydin C, Karakoca S, Yilmaz H, Yilmaz C, Yamalik K. The Use Of Dental Implants To Retain Thumb Prostheses: A Short-Term
Evaluation Of 2 Cases. Int J Prosthodont. 2008;21(2):138–40.

DOI: 10.9790/0853-2306065055 www.iosrjournals.org 52 | Page

 Implant Retained Silicone Finger Prosthesis With Customized Abutment And A Telescopic………

[10]. Brånemark R, Brånemark Pi, Rydevik B, Myers Rr. Osseointegration In Skeletal Reconstruction And Rehabilitation: A Review. J
Rehabil Res Dev. 2001;38(2):175–81.
[11]. Buckner H: Cosmetic Hand Prosthesis-A Case-Report - Orthotics And Prosthetics, 1980;34(3):41-45
[12]. Jean Pillet, Evelyn J. Mackin. O And P Library Aesthetic Restoration. Atlas Of Limb Prosthetics: Surgical, Prosthetic And
Rehabilitation Principles: Partial-Hand Amputations.
[13]. Livingstone Dp. The D-Z Stump Protector. Am J Occup Ther Off Publ Am Occup Ther Assoc. 1988 Mar;42(3):185–7.
[14]. Kanter Jc. The Use Of Rtv Silicones In Maxillofacial Prosthetics. J Prosthet Dent. 1970 Dec;24(6):646–53.
[15]. Mikey Fairley; Osseointegration: In The Wave Of The Future? | September 2006.The O&P Edge.

Figure Legends And Figures

Figure_1: Pre Operative View And Pre Operative Radiograph

Figure_2: Stage I Surgery – Implant Placement.

Figure_3: Post Operative Radiograph 4 Months After Surgery.

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 Implant Retained Silicone Finger Prosthesis With Customized Abutment And A Telescopic………

Figure_4: Stage Ii Surgery - Exposure Of Implant Head And Placement Of Healing Cap

Figure_5: Open Tray Post Attached Onto The Implant Head.

Figure_6: Attachment Of Implant Analogue On The Impression.

Figure_7: Customized Ball Attachment With Antirotation Notch And Customized Retentive Attachment
With Telescopic Coping.

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 Implant Retained Silicone Finger Prosthesis With Customized Abutment And A Telescopic………

Figure_8: Finger Prosthesis In Position – Dorsal View

Figure_9: Finger Prosthesis In Position – Ventral View.

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