JOURNAL CLUB PRESENTATION IN PROSTHODONTICS on ANDREW'S BRIDGE SYSTEM

ANDREW'S BRIGE SYSTEM IS EXPLAINED WITH 5 CASE REPORTS AND ONE REVIEW ARTICLE

1. Journal club presentation
NAMITHA AP
3
RD
YEAR
DEPT OF PROSTHODONTICS
Andrew’s Bridge System:
An EstheticOption
BhapkarP, BotreA, MenonP, GubrellayP
J Dent Allied Sci2015; 4:36-40.

2. CONTENTS
Introduction
Case report
Procedure
Discussion
Conclusion
Related articles
References

3. Introduction
Complete estheticsurgical replacement of the lost
tissues is difficult and unpredictable
unesthetic edentulous space

4. Dr.James Andrews of Amite, Louisiana, introduced the
fixed removable Andrews Bridge System (Institute of
Cosmetic Dentistry, Amite, La.)
improve or achieve comfort, hygiene, normal
phonetics and mostly normal esthetics.
Abutment tooth stabilization is combined with a
removable partial denture to resolve challenging
estheticproblems
ANDREW’S
BRIDGE
FIXED
RETAINERS
REMOVABLE
PONTICS
The fixed-
removable
partial denture
pontic assembly that is
removed by the
patient for preventive
maintenance

5. The retainers are joined
with prefabricated
castablebars and then
cast together, or a
prefabricated metal bar
is soldered to the metal
copings after casting.
The removable pontics
are retained by a clip on
the intaglio surface which
fits precisely over the bar
attachment.
increased reduction of the surface
adjacent to the edentulous space -
space for the mechanical lock of the
bar in the crowns and reduces the
possibility of distortion of the margins
during soldering

6. INDICATIONS
Absolute indications
Excessive residual ridge defect.
Ridge defects/jaw defects either due to trauma and/ or
surgical ablation.
Cleft palate patients with congenital or acquired
defects.
Relative indications
Often fixed partial denture failure with badly damaged,
cracked or weakened teeth by fillings and
disproportionate teeth.
Sometimes could be used in patients with periodontal
problems
abutments are
capable of supporting
a fixed partial denture
but the residual ridge
has been partially lost

7. Indications
Patients whose residual
ridge has a relationship to
the opposing dentition
that would prohibit the
estheticplacement of
the ponticsof a fixed
partial denture
Patients requiring
diastemasto harmonize
the natural dentition
Patients who have
extensive alveolar bone
and tissue loss

8. ADVANTAGES
It includes all the advantages of fixed and removable partial dentures with
better esthetics, hygiene along with better adaptability and phonetics.
It is comfortable and economical for patients.
There is no plate as in RPD.
No soft tissue impingement and the surrounding structures.
The system acts as stress breaker while transmitting unwanted leverage
forces.
Flexibility in placing denture teeth
Increased stability of the splinted teeth
The location of the bar near the gingival margin and the decreased
mobility of the splinted teeth support two principles of physics in increasing
the stability of the abutments.

9. CASE REPORT
A 35-year-old male patient
c/o: missing upper and lower front teeth
RTA 10 years back
multiple fractures of the middle and lower
third of the face involving the maxillary
and mandibular bones and loss of several
anterior teeth.
He was treated for the traumatic injuries,
and fixation was done with metal plates
and intermaxillaryfixation of the teeth was
done.
Was using interim RPDs replacing the
missing teeth for 10 year but was not
satisfied with the estheticsand function of
the prosthesis.
E/0examination -reduced upper and lower lip support and facial scars of previous injuries
I/O examination -missing teeth: 11, 12, 21,and 22 in the maxillary arch and 31, 32, 33, and 41 in the
mandibular arch

10. .
considerable
reduction in the
height and width
of the residual
alveolar ridge in
the maxillary
anterior region
(SiebertsClass III)
The bony defect in
the mandibular
arch was not
severe and could
be classified as a
Sieberts Class II
defect.
Generalized hypoplasia was seen on
the teeth with brownish stains.
Anterior open bite was present
43 was malaligned and discolored with
inadequate cusp tip anatomy
When viewed from occlusal
aspect, there was arch
asymmetry across the midline in
the maxillary and mandibular
arches

11. Intraoral periapical radiographs and
orthopantomographs were made.
Treatment
options for the
maxillary arch
implant
supported FDP
with autogenous
bone graft
fixed-removable
partial denture
Conventional
RPD
Conventional
FPD
fixation done in the facial bones and mandible
good bone support around the abutment teeth
(13, 23, 34, and 42).
require preprosthetic
surgeries such as onlay
grafts or
alloplastic grafts
possibly with soft tissue
regeneration -months
of healing period and
the outcome
may not have been
predictable
•asymmetry in the arch
across midline was not
allowing esthetic
placement of the artificial
teeth without
compromising the laws of
biomechanics
•bone loss-increase in
the length of the
pontics
•required corrections by
soft tissue grafts
not satisfying patient’s
needs,
and if not maintained
properly, it would have
caused
decalcification and
dental caries of the
adjacent teeth,
periodontal problems
such as inflammation of
the gingival
tissues
FINAL TREATMENT
PLAN

12. PROCEDURE
intentional endodontic treatment had to be done with
13 and 42 to receive PFM restorations.
13 was planned to be restored as 12 and 34 was
planned to be restored as 33 for esthetics.
Diagnostic
impressions
Study casts
mounted
Diagnostic
wax up

13. The master casts were poured using Type-IV gypsum product
and were mounted on a semi-adjustable articulator
Tooth
preparation
Impressions
Temporisation
13 and 23 to receive PFM crowns that
will be connected with a bar
attachment.
34 and 42 as abutments for PFM FDP
replacing 31, 32, 33, 41, and 42.
gingival retraction was done using
chemico-mechanical method, and final
impressions were made using poly-vinyl
siloxane impression material and two-
stage putty wash technique.
The prepared teeth were temporized
using tooth colored self-cure acrylic resin
by indirect technique.

14. The bar was positioned parallel to the ridge and
was attached on the palatal aspect of the
retainers
2-3 mm of space was left between the bar and the
crest of the alveolar ridge to facilitate
maintenance of hygiene by the patient.
casted in cobalt-chromium alloy
Wax pattern was also done for the copings of PFM
FDP replacing 31, 32, 33, 41, and 42 and was
casted.
Wax-up was done for PFM retainers with 13 and 23, connected with a prefabricated
castableplastic bar attachment (OT Bar Multiuse, Rhein83).
13 was waxed up to look like 12 for improved esthetics.
34 was waxed up to look like 33.

15. Metal trial was done for the maxillary and mandibular prostheses
Shade selection was
done for matching the
shade of ceramic
restorations with that of
acrylic denture teeth.
adjusted to match
the facial midline of
the patient

16. As 43 was discoloredand
slightly malalignedwith an
inadequate cusp tip anatomy,
a composite restoration was
done with 43 to obtain better
anatomy and esthetics
With the fixed components of
the maxillary prosthesis in
position, an irreversible
hydrocolloid impression was
made, and dental stone cast
was poured for the processing
of the RPD.
The ceramic build-up was done for the
mandibular PFM Bridge and the fixed retainer
part of the Andrews Bridge system and was
cemented over the prepared teeth with glass
ionomer cement

17. The waxed up trial denture was processed in
heat cure acrylic resin, finished and polished
and tried in patients mouth over the fixed
component of the Andrews Bridge system.
The undercut under the bar attachment was
blocked out with wax.
The clip was attached to the bar attachment
and was picked up in self-cure acrylic resin into
the RPD.
The denture was removed, finished, and
polished and it was checked for retention of the
bar and clip, esthetics, and phonetics
The patient was trained to place and remove the prosthesis.
The use of interdental brush under the bar attachment was
suggested for maintenance of oral hygiene along with
routine oral hygiene instructions. The periodic recall was
emphasized to check for the success of the treatment.

18. DISCUSSION only 9%of the patients with the anterior teeth
missing between the two canines did not have
ridge defects

19. Conclusions
In conditions, where conventional removable or fixed prosthesis is not a
feasible option as in the case presented above, a third treatment option of
Andrew’s Bridge can prove successful in restoring function, esthetics,
speech and closure of the defect.
Limited reports of the failure of such prosthesis are found in the literature.
The failures are mainly due to inadequate soldering. (eliminated by
attaching retainers to the bar in a single casting.)
The patient was comfortable with the final outcome and had pleasing
estheticsand phonetics.

20. RELATED ARTICLES
Prosthetic Rehabilitation of Mandibular Defects with Fixed-removable
Partial Denture Prosthesis Using Precision Attachment: A Twin Case Report
VimalKantilalMunot, Ramesh P. Nayakar, RaghunathPatil
Contemp ClinDent 2017;8:473-8.
Two case reports of attachment-retained fixed-removable hybrid prosthesis.
•A 29-year-old male patient
•chief complaint of unesthetic
appearance and difficulty in chewing
food.
•patient had undergone surgery for oral
tumorpresent on the lower right posterior
region of the jaw 1 year back, which
resulted in a large hard and soft tissue
deformity

21. maxillary arch-all the teeth were intact
with good periodontal conditions.
Radiographic examination revealed 20%
bone loss with lower right lateral incisor but
no clinical mobility(mild recession on distal
side)
Considering the clinical findings, a
fixed.removabledental prosthesis using
cement retention for the fixed metal fused
to ceramic bar framework and ball
retention for the RPD was planned for the
rehabilitation of the long span Kennedy
Class 3 partially edentulous space in the
lower right posterior region of the jaw
Mandibular arch examination revealed missing
lower right canine, premolars, and first molar
The restorative space of this Kennedy Class 3
defect was >15 mm.

22. Diagnostic impressions –Diagnostic wax up
Teeth preparation -to receive porcelain fused to metal restoration
with lower right central incisor, lateral incisor, and second molar
and all metal restoration with the third molar.
two-stage putty-light body impression of the lower arch was made
and poured in die stone and Temporisation
Wax patterns were fabricated for all the prepared teeth and a
wax custom bar running over edentulous deficit ridge was
connected to these prepared wax patterns.

23. Ball attachment patterns -attached to
the custom bar in the region of second
premolar and first molar
Spruing, investing, casting, and finishing
and polishing of this nickel–chromium
(Ni-Cr) alloy framework
Framework try-in was done in patient’s
mouth to assess the fit and availability
of interarchspace
The single-stage putty-light body
addition silicone pick-up impression of
the lower arch was made with
retention caps secured over the ball
attachment.
The cast was poured using die stone.
After satisfactory
try-in, the ceramic (VITA
Zahnfabrik, Germany) layering
was done for all the retainers,
except for lower right third
molar. The bisque trial was done to
evaluate the shade and
fit of the fixed prosthesis

24. Temporary denture base and the wax
occlusalrim were fabricated covering the
edentulous area.
The jaw relation was recorded followed by
articulation and teeth arrangement was
done to achieve unilateral balanced
occlusion with disclusionof all nonworking
side teeth on lateral excursion.
Waxed denture try.in was done followed
by acrylizationwith heat.polymerized
acrylic resin
Cementation of a metal framework with
auxiliary attachment was done using Type
1 Glass ionomercement and the
removable denture was attached to this
framework using the ball attachment
Postinsertion, hygiene, and home care
instructions were explained to the patient.
Recall visits of 1. and 3.month follow.upof
the prosthesis were found to be satisfactory
in terms of function and esthetics.
Laboratory remounting and finishing and
polishing of the prosthesis were done.
Standard retention caps were inserted in the
slot present on the intaglio surface of the RPD.

25. Case 2
A 24-year-old male patient
Prosthetic rehabilitation of defect in the right posterior region of the lower
jaw
Ameloblastomain the lower right posterior region of the jaw
operated for the same a year back, during which his lower right molars and
premolars were removed along with excised tissue
large soft and hard tissue defect in relation to the lower right posterior
region.
Restorative space of this Kennedy Class
2 defect was found to be >15 mm.

26. Mandibular arch examination revealed missing
lower right premolar and molars
The lower right canine showed recession but no
mobility
Radiographic examination revealed 30% bone
loss with a canine
considering the age and financial
constraints of the patient, a fixed.removable
prosthesis with precision attachment was
planned.

27. Abutment tooth preparations were
done with lower left and right central
incisor, left lateral incisor, and canine
to receive porcelain fused to metal
restoration.
A two-stage putty-light body addition
silicon impression of the lower arch
was made and poured in die stone
The pattern was invested and cast
with Ni.Cralloy, which was followed
by finishing and polishing of the
framework. Intraoral framework try.in
was done to assess the fit and
available interarchspace
Wax patterns were fabricated for all the
prepared teeth and a wax custom bar
running over the edentulous area was
connected to these prepared wax
patterns.
Ball attachment patterns (Rhein83, USA) were
attached to the custom bar in the region of
first premolar and first molar

28. Undercut blockoutof the framework was
done and single-stage putty-light body
addition silicone pickup impression was
made with retention caps placed over the
stud attachments and the cast was poured
with die stone.
Temporary denture base and the wax
occlusalrim were fabricated covering the
edentulous area.
The jaw relation was recorded followed by
facebowtransfer and articulation.
Teeth arrangement was done to achieve
unilateral balanced occlusion with disclusion
of all nonworking side teeth on lateral
excursion.
Ceramic layering was done with respect to
all the retainers and the bisque trial was
done to evaluate the shade and fit of the
fixed prosthesis

29. Waxed denture try-in was done followed by
acrylizationusing heat-polymerized acrylic
resin
Finishing and polishing of the prosthesis were
done.
Standard retention caps were inserted in the
slot present on the undersurfaceon the RPD.
Prosthesis framework with auxiliary
attachment was cemented using type 1 glass
ionomercement and the removable denture
was retained over this framework using the
ball attachment

30. Discussion
Hence, considering the age and financial status, precision
attachment-retained fixed-removable prosthesis was selected over
clasp-retained RPD to rehabilitate Kennedy Class 2 and 3 hard and soft
tissue defect with a crown height space of >15 mm.
Repeated removal and placement of prosthesis result in wear of the
retention clip, requiring periodic replacement of the clip.
Daily oral hygiene maintenance and care of the prosthesis are required on
the part of the patient.

31. Prosthetic rehabilitation of severe Siebert’s
Class III defect with modified
Andrews bridge system
Manu Rathee, NehaSikka, SahilJindal1, AshutoshKaushik
A 32-year-old male
c/o : unesthetic appearance of the face due to depression in the lip region on the left
side of the face.
Extra orally, two scars and a prominent depression in lower lip region were noticeable on
the left side of the face.
On intraoral examination, mandibular anterior and premolar teeth were missing and a
bony defect (12 mm ×19 mm) with flabby tissue at the base was present at the
respective region
Tissues in the
defect region
were 12 mm
below the
cervical
margins of the
adjacent
teeth-Siebert’s
Class III defect
relative positions
of the two
mandibular
segments and the
reconstruction
plate comminuted mandibular fracture in symphseal-parasymphyseal
region on the left side of face 3 years back

32. This segment of the mandible along with five teeth (mandibular anteriors
and premolars) was removed during open reduction of the fracture
followed by placement of titanium reconstruction plate.
The intraoral closure of the defect was done by placing the temporal flap
over the defect
The modification planned was to replace the costlier prefabricated bar
and sleeve attachment of conventional Andrews system with two small disc
shaped magnets.
Diagnostic
impressions
and casts
The selected
abutment
teeth (41, 36)
were
prepared for
metal
ceramic
restorations.
Putty wash
impression
Provisional
crowns

33. The maxillary and mandibular casts were mounted, and the wax pattern
was fabricated in Blue Inlay Wax comprising of a rectangular bar
connecting copings on both the prepared teeth.
The pattern was casted in Nickel chrome alloy
The cast metal framework was tried in patient and checked for any
impingement of the basal tissues
The framework was again tried in after application of Porcelain
Framework was reseatedon the cast and a self-polymerizing clear acrylic
flange was fabricated from the bar in the framework till the soft tissues on
the base of the defect.
The tissue surface of the flange
simulated the sanitary pontic design

34. A magnet (NdFeBmagnet,
Ni-plated–disc shaped
magnet 2 mm ×1.5 mm in
size, TechtoneElectronics,
Mumbai, India) was placed
in buccolingualand
mesiodistalcenterof the
lingual surface of this flange
The framework was
cemented permanently,
and the removable
component was placed
magnets do not exert any deleterious effects on the
human tissues.
support in this system is mainly derived from the
abutment teeth so no pressure was applied to the
tissues at the base of the defect which were devoid of
any bone support.

35. SHORTCOMINGS OF THE
MODIFICATION
The surfaces of magnets are exposed to oral fluids, which may lead to
tarnish and corrosion.
This may produce disruption of the protective coating of the magnets
leading to some cytotoxic effects.
It may result in the decreased retentive force upon usage.
Hence maintaining constant recalls and replacing the magnets as early as
signs of corrosion develop may play a significant role in the durability and
functioning of the appliance.
The surgical grafting procedures still remain the best treatment options for
the cases with unesthetic ridge defects.

36. Andrews Bridge System: An Excellent
Treatment Modality For Replacement of
Anterior Dento-Alveolar Defects
BhushanKumar, AndrewsNavinKumar, PrabhdeepKaur Sandhu
49 years old female patient
C/O : unpleasant smile.
H/O : RTA 3 months back in which she lost her upper
front teeth.
E/O examination: revealed the lack of lip support
I/O examination: showed missing 11,12,13,14 and their
associated alveolar structure (Seibert’s class III defect).
15 and 16 were root canal treated.
This case was an ideal indication for Andrew’s bridge
system.

37. Step 2:(Removable component fabrication) after blocking under
surface of Bar with modelling wax, impression was made in
polyvinyl siloxanematerial.
Step 1: (Fixed
component
fabrication) crown
preparation done
on 21,15 and PFM
crowns on 21,15
connected with
bar(using pre-
formed OT Bar
Multiuse, Rhein83)
during casting
procedure.
A metal major connector
was planned with diagonal
extension in second
quadrant for providing
additional tissue support,
indirect retention under
oblique forces and most
important a cross arch
stabilisation.
After proper block-out on master cast, firstly permanent record
base was fabricated in heat cure resin on metal frame in
edentulous area.
A circumferential clasp was incorporated around 27 for retention
purpose. After finishing it was checked for adaptation intra-orally.
After satisfied trial a window was created for attachment of metal
housing–nylon clip assembly over underlying Bar.

38. A separate crown on 16 was fabricated. After checking for esthetics,
occlusion these were cemented with luting glass ionomercement.
After a passive seating of denture base, cold cure
acrylic resin was used to attach metal housing
with the denture base (direct method). Teeth
arrangement was done with slight mal-alignment
to give a mirror appearance to opposite
quadrant using dentogenic concept
After clinical trial, the prosthesis was
processed in heat cure acrylic resin in
artificial teeth region.
Final finished prosthesis was checked for
estheticsand function

39. An Evidence Based Restoration of Esthetically
Challenged Maxillary Anterior Arch with
Andrews Bridge System -A Case Report with 5
Years of Follow Up
Balakrishnan D, Ahmad M, AlbinaliA, AreashiA, NaimH
A 46 year old male patient reported with the chief
complaints of missing anterior teeth in the upper jaw
and his unaestheticappearance.
His past dental history revealed the loss of teeth due to
trauma 4 years back
Intra oral examination showed loss of maxillary left and
right central incisors

40. There were no clinically significant findings on the remaining maxillary teeth.
The condition of abutment teeth was evaluated and the treatment plan
was to fabricate the fixed removable prosthesis to restore this esthetically
challenged maxillary edentulous region.
The abutment teeth were prepared for ceramo-metal preparations with
more reduction on the axial walls of abutments approximating the pontic
to allow space for joining the supra-structure bar and metal retainer.
It reduces the chances of breakage of the bar and retainer at this junction.
There was an adequate amount of alveolar
bone loss in both vertical and horizontal
direction at the maxillary anterior edentulous
site, which was confirmed with intraoral
radiographs

41. Double mix single step impression technique was used to make the final
impression using light and medium body elastomeric impression material.
Master casts were poured and mounted in the articulator.
Inlay wax patterns for the retainers were made on the prepared dies.
Supra-structure bar was made with inlay wax and attached to the wax
pattern.
The bar, which is positioned for the least restrictive path of insertion, should
provide at least 1.5 mm of occlusalclearance and should be positioned in
the same horizontal position as the centerof the ponticteeth.
The entire wax assembly was then cast.
Finishing and polishing of the metal framework was done in the
conventional manner.

42. Metal frame work was inserted in the mouth to verify
the proximal, marginal and occlusalrelationships
and the shade selection was done.
Adequate space for the substructure to replace the
missing teeth was verified.
Wax pattern was fabricated over the super-
structure and casted, finished and polished.
The substructure was verified to check the fit over
the super-structure.
Self-cure acrylic base plate was adapted over the
substructure and bite registration was done.
Teeth arrangement was carried out and patient
was called for try-in appointment.
The porcelain was finally contoured and stained at this point
before it is glazed.
The flange was festooned and removable ponticwas
processed in heat cure acrylic
A 0.5 mm deep groove was made on
the facial and palatal side of the super-
structure (retention)

43. The tissue surface of the bar was
grounded and polished to relieve
contact with the interdental
papilla.
At the final insertion appointment, the restoration was adjusted before cementation.
Framework was cemented first without the ponticon the bar to assure that the abutments were fully
seated.
The framework should not impinge on the tissue

44. The patient was trained to properly place and remove the removable
denture from the fixed component of Andrew's bridge.
Proper oral hygiene instructions were given to the patient and recalled
after 2 weeks to check the adaptability.
Home care instructions were given and recalled at regular intervals.
After 5 years patient was evaluated to access the success of treatment
which was well adapted to the Andrew's bridge system

45. Evaluation of a fixed removable partial
denture: Andrews bridge system
Everhart RJ, Cavazos JrE.
The Journal of prosthetic dentistry. 1983 Aug 1;50(2):180-4.
A loss of tissue can facilitate fabrication by
providing more crown length available for the
attachment of the bar
There is increased clearance between the bar and
the tissue, simplifying oral hygiene procedures after
insertion of the prosthesis.
If tissue interference persists, the tissue should be
recontouredby surgery or electrosurgery

46. Bar should follow the residual ridge and is
positioned in the approximate centerof the
replacement teeth
Patient selection is critical and problems that
develop are essentially the result of
diagnostic errors during treatment planning.
A minimum of 2 mm vertical bar height is
required for sufficient strength to support the
removable portion of the restoration.
It is a physiologic advantage to place the
bar as close to the gingival margin of the
crown as technically feasible, but tissue
contact is not desirable
incisal
relationships and reduced crown
length -long-term
prognosis is jeopardized and can
result in a fractured
solder joint

47. If the inferior surface of the bar contacts the tissue and particularly if the
patient has a casual approach to oral hygiene, tissue proliferation can
result.
Another subtle but crucial factor to consider is the relation of the path of
withdrawal of the removable segment to the path of dislodgment of the
fixed segment.
bar has been inclined so the path of
withdrawal of the flange portion is
divergent from the displacing forces
exercised on the fixed portion.
forces exerted in any one instance are minimal, the repeated removal and insertion of the
removable segment in the same direction as the long axis of the retainers insidiously results in a
broken cement bond

48. SUMMARY
LOCATION
ECONOMICAL
CONSTRAINTS
OF PATIENT
LENGTH OF
EDENTULOUS
SPAN
FUNCTION
RETENTION
Selection criteria for precision attachment

49. References
BhapkarP, BotreA, MenonP, GubrellayP. Andrew's Bridge System: An EstheticOption. J
Dent Allied Sci2015; 4:36-40.
MunotVK, NayakarRP, PatilR. Prosthetic rehabilitation of mandibular defects with fixed-
removable partial denture prosthesis using precision attachment: A twin case report.
Contemp ClinDent 2017;8:473-8.
RatheeM, SikkaN, Jindal S, KaushikA. Prosthetic rehabilitation of severe Siebert’s Class III
defect with modified Andrews bridge system. ContempClinDent 2015;6:S114-6.
Kumar B, Kumar A, Sandhu PK. Andrews Bridge System: An Excellent Treatment Modality For
Replacement of Anterior Dento-Alveolar Defects.
Balakrishnan D, Ahmad M, AlbinaliA, AreashiA, NaimH (2016) An Evidence Based
Restoration of EstheticallyChallenged Maxillary Anterior Arch with Andrews Bridge System -
A Case Report with 5 Years of Follow Up. Dentistry 6: 357.
Everhart RJ, Cavazos JrE. Evaluation of a fixed removable partial denture: Andrews bridge
system. The Journal of prosthetic dentistry. 1983 Aug 1;50(2):180-4.