Diagnosis and Treatment Planning in Fixed Partial Dentures / orthodontic courses by Indian dental academy

DIAGNOSIS AND TREATMENT PLANNING IN FIXED PARTIAL DENTURES

Introduction

- Fixed prosthodontic treatment can offer exceptional satisfaction

for both patient and the dentist.

- Fixed prosthodontics can transform an unhealthy, unattractive

dentition with poor function into a comfortable, healthy occlusion

capable of giving years of further service while greatly enhancing

esthetics.

- To achieve success, requires meticulous attention to every detail

from initial patient interview through the active treatment phases

to a planned schedule of follow-up care.

- Problems encountered during treatment can often be traced to

errors and omissions during history taking and initial

examination.

- Diagnosis: It is the examination of the physical state, evaluation

of mental or psychological makeup and understanding the needs

of each patient to ensure a predictable result.

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- Treatment planning: It means developing a course of action that

encompasses the ramifications and sequelae of treatment to serve

the patient’s needs.

Chief Complaint:

It should be recorded in patients own words. The accuracy and

significance of patient’s primary reason /reasons should be analyzed

first. This will reveal problems and conditions of which the patient is

often unaware.

History:

A patient’s history should include all necessary information

concerning the reasons for seeking treatment, along with any personal

details and past medical and dental experiences that are pertinent. A

screening questionnaire is useful for history taking.

Medical History:

An accurate and current general medical history should include

any medication the patient is taking as well as all relevant medical

conditions.

a) Any disorders that necessitate the use of antibiotic

premedication, any use of steroids or anticoagulants and any

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previous allergic responses to medication or dental materials

should be recorded.

b) Any conditions affecting the treatment plan e.g.:

various radiation therapy, haemorrahgic disorders etc. should be

recorded.

c) Possible risk factors to the dentist and auxiliary

personnel, e.g. carriers of Hepatitis B, Aids or Syphilis are

recorded so that adequate measures can be followed when

treating known carriers.

Dental History:

Periodontal, restorative and endodontic history are first noted.

Orthodontic history should be an integral part of the assessment of a

prosthodontic dentition. Occlusal adjustment may be needed to promote

long term positional stability of the teeth and reduce or eliminate

parafunctional activity. Restorative treatment can often be simplified by

minor tooth movement. When a patient is contemplating orthodontic

treatment, much time can often be saved if minor tooth movement for

restorative reasons is incorporated from the start.

TMJ dysfunction history

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A history of pain or clicking in the temporomandibular joints or

neuromuscular symptoms, such as tenderness to palpation, may be due

to TMJ dysfunction which should be treated before fixed prosthodontic

treatment begins.

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EXTRAORAL EXAMINATION

Cervical lymph nodes, TMJ and muscles of mastication are

palpated.

Temporomandibular joints:

The TMJ is palpated bilaterally just anterior to the auricular

tragic while having the patient open and close his lower jaw.

Tenderness, clicking or pain on movement is noted. Maximum

jaw opening less than 40mm indicates jaw restriction, because the

average opening is greater than 50mm. Any deviation from the midline

is also recorded. Maximum lateral movement can be measured (normal

is about 12mm).

Muscles of mastication

A brief palpation of masseter, temporalis, medial pterygoid,

lateral pteregoid, trapezius and sternocleido mastoid muscles may reveal

tenderness. The patient may demonstrate limited opening due to spasm

of the masseter or temporalis, muscle.

Lips:

Next, the patient is observed for tooth exposure during normal

and exaggerated smiling. This may be critical in treatment planning and

particularly for margin placement of metal-ceramic crowns.

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INTRAORAL EXAMINATION

- First the patient’s general oral hygiene is observed.

- The presence or absence of inflammation should be noted along

with gingival architecture and stippling. The existence of pockets

should be entered in the record and their location and depth

chartered.

- The presence and amount of tooth mobility should be recorded

with special attention paid to any relationship with occlusal

prematurities and to potential abutment teeth.

- Check for a band of attached gingiva around all the teeth,

particularly around teeth to be restored with crowns. Mandibular

3rd molars frequently do not have attached gingiva around the

distal segment (30% to 60% of cases).

- The presence and location of caries is noted. The amount and

location of caries, coupled with an evaluation of plaque retention,

can offer some prognosis for new restorations that will be placed.

It will also help the preparation designs to be used.

- Finally an evaluation should be made of the occlusion. The

amount of slide between the retruded position and the position of

maximum intercuspation should be noted. Non-working

interferences if present, should be evaluated. The presence or

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absence of simultaneous contact on both sides of the mouth

should be observed.

DIAGNOSTIC CASTS

Articulated diagnostic casts are essential in planning fixed

prosthodontic treatment. They provide critical information not directly

available during the clinical examination, static and dynamic

relationships of the teeth can be examined without interference from

protective neuromuscular reflexes. They also reveal those aspects of

occlusion not detectable within the confines of the mouth.

To accomplish their intended goal, they must be accurate

reproductions of the maxillary and mandibular arches made from

distortion free alginate impressions. (The casts should contain no

bubbles as a result of faulty pouring, nor positive nodules on the

occlusal surfaces ensuing from air entrapment during the making of the

impression).

The diagnostic casts should be mounted on a semiadjustable

articulator with a face bow. By the use of lateral interocclusal records or

check bites, a reasonably accurate simulation of jaw movements will be

possible. It is important that the mandibular cast be set in a relationship

determined by the patient’s optimum condylar position (centric relation

position).

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Advantages of diagnostic casts:

1) For diagnosing problems and arriving at a treatment plan.

2) Allow an unobstructed view of the edentulous spaces and an

accurate assessment of the span length, as well as occlusogingival

dimension.

3) Curvature of the arch in the edentulous region can be determined

so that it will be possible to predict whether the pontic/pontics will

act as a lever arm on the abutment teeth.

4) Length of the abutment teeth can be accurately gauged to

determine which preparation designs will provide adequate

retention and resistance.

5) The true inclination of the abutment teeth will also became evident,

so that the problems in a common path of insertion can be

anticipated.

6) Mesiodistal drifting, rotation and faciolingual displacement of

prospective abutment teeth can be clearly seen.

7) A thorough evaluation of wear facets – their number, size and

location is possible.

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8) Discrepancies in the occlusal plane become very apparent on the

articulated casts.

9) Occlusal discrepancies can be evaluated and the presence of centric

prematurities or excursive interferences can be determined.

10) Teeth that have supraerupted into the opposing edentulous spaces

are easily spotted and the amount of correction needed can be

determined.

11) Diagnostic wax-up can be carried out in situations calling for the

use of pontics which are wider or narrower than the teeth that

would normally occupy the edentulous space.

Full-mouth Radiographs

Radiographs provide the information to help correlate all the facts

that have been collected in listening to the patient, examining the mouth

and evaluating the diagnostic casts.

- Radiographs should be examined carefully for signs of

caries, both on unrestored proximal surfaces and recurring

around previous restorations.

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- The presence of periapical lesions, as well as the existence

and quality of previous endodontic treatments, should be

noted.

- General alveolar bone levels, with particular emphasis on

prospective abutment teeth should be observed.

- The crown-root ratio of abutment teeth can be calculated.

The length, configuration and direction of these roots

should also be examined.

- Any widening of periodontal ligament should be

correlated with occlusal prematurities or occlusal trauma.

- Any evaluation of the thickness of cortical plate of bone

around the teeth and of the bone trabeculae can be made.

- The presence of retained root tips or other pathosis in the

edentulous areas should be recorded.

Vitality Testing

Prior to any restorative treatment, pulpal health must be assessed,

usually by measuring the response to percussion and thermal and

electrical stimulation. A diagnosis of non-vitality can be confirmed by

preparing a test cavity before the administration of local anesthetic.

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SELECTION OF AN ARTICULATOR

A distinction must be made between mounting for diagnosis and

mounting for treatment. The attachment of casts to an articulator for

diagnosis will be done with the condyles in a centric relation position.

Also when the casts are articulated for restoration of a significant

portion of occlusion, it may also be done with condyles in centric

relation position. Mounting casts for restoration of only a small part of

occlusion will be done with teeth in a portion of maximum

intercuspation.

Articulators vary widely in the accuracy with which they

reproduce the movements of the mandible.

1) At the lower end of scale is a non-adjustable articulator. It is

usually a small instrument that is capable of only a hinge

opening. The distance between the teeth and the axis of rotation

on the small instrument is considerably shorter than in the skull

with a resultant loss of accuracy. Drastic differences between the

radius of closure on the articulator and in the patient’s mouth can

affect the placement of morphologic featuers such as cusps,

ridges and grooves on the occlusal surface of the teeth being

restored.

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2) A semi-adjustable articulator is an instrument whose larger size

allows a close approximation of anatomic distance between the

axis of rotation and the teeth. If the casts are mounted with a

facebow using no more than an approximate transverse horizontal

axis, the radius of movement produced on the articulator will

reproduce the arc of closure with relative accuracy and any

resulting error will be slight. The semiadjustable articulator

reproduces the direction and endpoint, but not the intermediate

track of some condylar movements. Inter condylar distances are

not totally adjustable on semiadjustable articulators. They can be

adjusted to small, medium and large configurations. This type of

articulator can be used for the fabrication of most single units and

fixed partial dentures.

3) A fully adjustable articulator is designed to reproduce the entire

character of border movements, including immediate and

progressive lateral translation, and the curvature and direction on

condylar inclination. Intercondylar distance is completely

adjustable. Since this instrument is very expensive and demands

high degree of skill and time, it is used primarily for extensive

treatment, requiring the reconstruction of an entire occlusion.

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(To set the condylar inclinations on a semiadjustable instrument,

interocclusal records or check bites are used, when the interocclusal

record is removed from an arcon articulator, and the teeth are closed

together, the condylar inclination will remain the same. However, when

the teeth are closed on a non-arcon articulator, the condylar inclination

changes, becoming less steep).

Arcon articulators are more widely used because of their

accuracy and the ease with which they disassemble to facilitate the

occlusal waxing required for cast restorations. This feature makes this

type of articulator (arcon) more difficult for arranging denture teeth. The

centric position is less easily maintained when occlusion on all of the

posterior teeth is being manipulated. Therefore the non-arcon instrument

has been more popular for the fabrication of complete dentures.

Locating the transverse hinge axis

To achieve the highest possible degree of accuracy from an

articulator, the casts mounted on it should be closing around an axis of

rotation that is as close as possible to the transverse horizontal axis of

the patient’s mandible.

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A) The most accurate way to determine the hinge axis is by the “trial

and error” method developed by McCollum and Stuart in 1921

(using a kinematic face bow).

B) Arbitrary face bows can also used. But they must have an

acceptable accuracy. Caliper style ear face bows possess a

relatively high degree of accuracy with 75% of the axes located

by it falling within 6mm of the true hinge axis. These face bows

are designed to be self centering, so that little time is wasted in

centering the bite fork and adjusting individual side arms.

TREATMENT PLANNING FOR SINGLE TOOTH

RESTORATIONS

The most common question arising in treatment planning for

single tooth restorations is than in what circumstances should cemented

restorations made from cast metal or ceramic be used instead of

amalgam or composite resin restorations. The selection of the material

and design of the restoration is based on several factors:

1. Destruction of tooth structure: If the amount of destruction

previously suffered by the tooth is such that the remaining tooth

structure must gain strength and protection from the restoration,

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cast metal or ceramic is indicated over amalgam or composite

resin.

2. Plaque control: The use of cemented restoration demands the

institution and maintenance of good plaque-control program to

increase the changes for success of the restoration. Many teeth

are seemingly prime candidates for cast metal or ceramic

restorations, based solely on amount of tooth destruction that has

previously occurred. However, when these teeth are evaluated

from the oral environment, they may in fact be poor risks for

cemented restorations.

3. Retention: Full veneer crowns are unquestionably the most

retentive. However, maximum retention is not nearly as

important for single-tooth restorations as it is for fixed partial

denture retainers. It does become a special concern for short teeth

and removable partial denture abutments.

INTRA CORONAL RESTORATIONS

When sufficient coronal tooth structure exists to retain and

protect a restoration under the anticipated stresses of mastication, an

intracoronal restoration can be employed. Here the restoration itself is

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dependent on the strength of the remaining tooth structure for structural

integrity.

a) Glass ionomer:

i) In small lesions where extension can be kept minimal.

ii) Useful for restoring Class 5 lesions caused by erosion or

abrasion.

iii) Also employed for incipient lesions on the proximal surfaces

of posterior teeth by the use of “tunnel” preparation which

leaves the marginal ridge intact.

iv) Very useful for the restoration of root caries in geriatric and

periodontal patients.

v) Serves as an interim treatment restoration to assist in the

control of a mouth with rampant caries.

b) Composite resin

i) In minor to moderate-lesions in esthetically critical areas.

ii) Due to polymerization shrinkage and insufficient abrasion

resistance, its use on posteriors should be restricted to small

occlusal and mesio-occlusal restorations on first molars.

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c) Simple amalgam

i) Simple amalgam, without pins or other auxiliary retention is

widely used for one-to-three-surface restoration of minor-to-

moderate sized lesions in esthetically non-critical areas.

ii) They are best used when more than half of coronal dentin is

intact.

d) Complex amalgam

i) Augmented by pins or other auxiliary means of retention, it

can be used to restore teeth with moderate to severe lesions, in

which less than half of the coronal dentin remains.

ii) It can be used as a final restoration when a crown is

contraindicated because of limited finances.

Ideally, however, a crown should be constructed over the pin

retained amalgam, using it as a core or foundation restoration.

e) Metal inlay

i) Minor to moderate lesions on teeth where the esthetic

requirements are low can be restored with this restoration.

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ii) Pre-molars should have one intact marginal ridge to preserve

structural integrity.

iii) Additional bulk of the tooth structure found in a molar,

permits the use of this type in a MOD configuration.

f) MOD Inlay:

i) Can be used for restoring moderately large lesions on

premolars and molars with intact facial and lingual surfaces.

ii) It can accommodate a wide isthmus and up to one missing

cusp on a molar.

iii) Cannot be used as a retainer for fixed partial denture.

EXTRA CORONAL RESTORATIONS

If insufficient tooth structure exists to retain the restoration within

the crown of the tooth, an extracoronal restoration, or crown is needed.

a) Partial veneer crown:

i) Leaves one or more axial surfaces unveneered.

ii) It will provide moderate retention and can be used as a

retainer for short span fixed partial dentures.

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b) Full metal crown:

i) To restore teeth with multiple defective axial surfaces or when

less than half of coronal dentin remains.

ii) Provides maximum use restricted to situations, where there

are no esthetic requirements.

c) Metal-ceramic crown

i) Provides maximum retention.

ii) Combines full coverage with good cosmetic result.

d) All-ceramic crown

i) Their use must be restricted to situations likely to produce low

to moderate stress usually used for incisors.

e) Ceramic veneer

i) Produces good cosmetic result on otherwise intact anterior

teeth that are marred by severe staining or developmental

defects restricted to facial surface of the tooth.

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TREATMENT PLANNING FOR REPLACEMENT OF MISSING

TEETH

Several factors must be weighed when choosing the type of

prosthesis to be used in any given situation. Important ones are:

a) Biomechanical factors.

b) Periodontal factors.

c) Esthetics.

d) Financial factors.

e) Patient’s wishes.

Abutment Evaluation

- Abutment teeth are called upon to withstand the forces

normally directed to the missing teeth, in addition to those

usually applied to the abutments.

- Whenever possible an abutment should be a vital tooth.

However, a tooth that has been endodontically treated

which is asymptomatic with radiographic evidence of a

good seal and complete obturation of the canal, can be

used as an abutment. If the endodontically treated tooth

does not have sound tooth structure, it must treated

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through the use of a dowel core, or a pin-retained amalgam

or composite resin core.

- Teeth that have been pulp capped in the process of

preparing the tooth should not be used as FPD abutments

unless they are endodontically treated.

- The supporting tissues surrounding the abutment teeth

must be healthy and free from inflammation before any

prosthesis can be contemplated.

- Normally, abutment teeth should not exhibit mobility,

since they will be carrying an extra load.

The roots and their supporting tissues should be evaluated for 3 factors:

1. Crown-root ratio.

2. Root configuration.

3. Periodontal ligament area.

1) Crown root ratio

It is a measure of the length of the tooth occlusal to the alveolar

crest of bone compared with the length of the root embedded in the

bone. As the level of the alveolar bone moves apically, the lever arm of

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that portion out of bone increases and the chance for harmful lateral

force is increased.

- The optimum crown-root-ratio for a tooth to be utilized as

a fixed partial denture is 2:3 and a 1:1 ratio is the

minimum acceptable under normal circumstances.

- However, there are situations in which a crown-root-ratio

greater than 1:1 (i.e. length of crown greater than length of

the tooth) may be considered adequate. If the occlusion

opposing a proposed fixed partial denture is comprised of

artificial teeth, occlusal force will be diminished, with less

stress on abutment teeth.

Studies by Klaffenbach in 1936 have shown that occlusal

forces exerted against prosthetic appliances has been

shown to be considerably less than that against natural

teeth.

FPD against RPD 26.0lb

FPD against FPD 54.4 lb

FPD against natural teeth 150.0lb

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2) Root configuration

- Roots that are broader labiolingually are preferable to

roots that are round in cross section.

- Multirooted posterior teeth with widely separated roots

will offer better periodontal support than roots that

converge, fuse or generally present a conical

configuration. The tooth with conical roots can be used as

an abutment for a short span fixed partial denture if all

other factors are optimal.

- A single rooted tooth with evidence of irregular

configurations or with some curvature in the apical third is

preferable to the tooth that has a nearly perfect taper.

3) Periodontal ligament area:

- Larger teeth have greater surface area and are better able

to bear added stress.

- Kalkwarf in 1986 showed that millimeter per millimeter,

the loss of periodontal support from root resorption is only

1/3 to ½ as critical as the loss of alveolar crestal bone.

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- Johnston et al in 1971 in their statement designated as

“Ante’s law” said that the root surface area of the

abutment teeth had to equal or surpass that of the teeth

being replaced with pontics.

- Fixed partial dentures with short pontic spans have a better

prognosis than those with long spans. Failures with long

span bridges have been attributed to leverage and torque

than overload. Biomechanical factors and material failure

play an important role in the failure for long span

restorations.

- There is evidence that teeth with poor periodontal support

can serve successfully as fixed denture abutments in

carefully selected cases. Nyman S, Lindhe in 1976 said

that teeth with severe bone loss and marked mobility can

be used as fixed partial denture and splint abutments.

Elimination of mobility is not the goal in such cases, but to

prevent further increase in mobility of that tooth. They

said that this is possible in highly motivated patients who

are proficient in plaque removal.

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Biomechanical Considerations

All fixed partial dentures, long or short spanned bend and flex.

- Bending or deflection varies directly with the cube of the

length and inversely with the cube of occlusogingival

thickness of the pontic.

- Compared with a fixed partial denture having a single

tooth pontic span, a two tooth pontic span will bend 8

times as much. A three tooth pontic will bend 27 times as

much as a single pontic.

- A pontic with a given occlusogingival dimension will

bend 8 times if the pontic thickness is halved. To minimize

flexing caused by long/short spans, pontic designs with a

greater occlusogingival dimension should be selected. The

prosthesis may also be fabricated of an alloy with a higher

yield strength, such as nickel-chromium.

- The dislodging forces of a fixed partial denture retainer

tend to act in a mesiodistal direction, as opposed to the

more common buccolingual direction of forces on a single

restoration. Preparations should be modified accordingly

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to produce greater resistance and structural durability.

Multiple grooves, including some on buccal and lingual

surfaces are commonly employed for this purpose.

- Double abutments are sometimes used as a means of

overcoming problems created by unfavourable crown-root

ratios and long span. There are several criteria that must be

met, if a secondary abutment is to strengthen the fixed

partial denture.

a) A secondary abutment must have atleast as much

root surface area and as favourable a crown-root

ratio as the primary abutment.

E.g.: A canine can be used as a secondary abutment

to a first premolar primary abutment, but it would be

unwise to use a lateral incisor as a secondary

abutment to a canine primary abutment.

- Arch curvature has its effects on the stresses occurring in a

fixed partial denture. When the pontics lie outside the

intraabutment axis line, the pontics act as a lever arm

which can produce a torquing movement. This is a

common problem in replacing all 4 maxillary incisors with

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a fixed partial denture. The best way to offset this torque is

by gaining additional retention in the opposite direction of

the lever arm. The secondary retention must be at a

distance equal to the length of the lever arm from the

interabutment axis.

- E.g.: The first pre-molars some times are used as

secondary abutments for maxillary four-pontic canine-to-

canine FPD.

SPECIAL PROBLEMS

A) Pier abutments: An edentulous space can

occur on both sides of a tooth, creating a lone, freestanding pier

abutment. Physiologic tooth movement, arch position of the

abutments and a disparity in the retentive capacity of the retainers

can make a rigid 5-unit fixed partial denture as a less than ideal plan

of treatment.

- It has been theorized that forces are transmitted to the

terminal retainers as a result of the middle abutment acting

as a fulcrum, causing failure of the weaker retainer.

However a photoelastic stress analysis study conducted by

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Standlee and Caputo in 1988 has shown that the prosthesis

bends rather than rocking.

- The retention on the smaller anterior tooth is usually less

than that of the posterior tooth because of its smaller

dimensions. The loosened casting will leak around the

margin and caries is likely to become extensive before

discovery.

- The use of a non-rigid connector has been recommended

to reduce this hazard. The movement in a non-rigid

connector is enough to prevent the transfer of stresses

from the segment being loaded to the rest of the FPD.

- The most commonly used non-rigid design is a T shaped

key that is attached to the pontic and a dove tail key way

placed within a retainer.

- The key way of the connector should be placed within the

normal distal contours of the pier abutment and the key

should be placed on the mesial side of the distal pontic.

B) Tilted Molar Abutments

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A common problem that occurs is the mandibular second molar

abutment that has tilted mesially into the space formerly occupied by the

first molar. There is further complication if 3rd molar is present. It will

usually have drifted and tilted with the 2nd molar.

- If the encroachment is slight, the problem can be remedied

by restoring or recontouring the mesial surface of the third

molar with an overtapered preparation on the second

molar.

- If the tilting is severe, other corrective measure will have

to be followed. The treatment of choice is uprighting of

the molar by orthodontic treatment. The third molar if

present is often removed to facilitate the distal movement

of the 2nd molar. After removal of the appliance, the teeth

are prepared and a temporary FPD is fabricated to prevent

post treatment relapse.

- A proximal half crown can be used as a retainer on the

distal abutment. This preparation design is a 3 ¼ crown

that has been rotated 90°. It can be used only if the distal

surface is untouched by caries.

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- A telescoping crown and coping can also be used as a

retainer for the tilted molar. A full crown preparation with

heavy reduction is made to follow the long axis of the

tilted molar. An inner coping is made to fit the tooth

preparation. The proximal half crown that will serve as the

retainer for the FPD is fitted over the coping.

- A non-rigid connector is another solution to the problem.

A full crown preparation is done on the tilted molar, with

its path of insertion parallel with the long axis. A box form

is placed on the distal surface of the premolar to

accommodate a keyway in the distal of the premolar

crown.

C) Canine Replacement Fpds

This is a problem because often the canine lies outside the

interabutment axis. The abutments are the lateral incisor, usually the

weakest in the entire arch and the first premolar, the weakest posterior

tooth. A FPD replacing maxillary canine is subjected to more stress

than that replacing a mandibular canine, since forces are transmitted

outward on the maxillary arch. So the support from secondary

abutments will have to be considered. An edentulous space created by

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the loss of a canine and any 2 contiguous teeth is better restored with a

removable partial denture.

D) Cantilever FPDs

A cantilever FPD is one that has an abutment or abutments at one

end only, with the other end of the pontic remaining unattached. This is

a potentially destructive design with the lever arm created by the pontic.

- Abutment teeth for cantilever FPDs should be evaluated

for lengthy roots with a favourable configuration, good crown

root ratios and long clinical crowns.

- Generally, cantilever FPDs should replace only one tooth

and have atleast 2 abutments.

- A cantilever can be used for replacing a maxillary lateral

incisor with canine as the abutment. There should be no occlusal

contact on the pontic in either centric or lateral excursions.

- A cantilever pontic can also be used to replace a missing

1st premolar with second premolar and 1st molar as abutment. The

occlusal contact should be limited to the distal fossa on the 1st

premolar pontic.

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- Cantilever FPDs can also be used to replace molars when

there is no distal abutment present. Most commonly the 1st molar

is replaced with the 2 premolars as abutments. The pontic should

have maximum occlusogingival height, there should be light

occlusal contact on the pontic with no contact in any excursions.

Buccolingual width should be kept minimum and the pontic

should resemble more of a premolar.

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Conclusion

The scope of fixed prosthodontic treatment can range from the

restoration of a single tooth to the rehabilitation of the entire occlusion.

Single teeth can be restored to full function and improvement in

cosmetic effect can be achieved. Missing teeth can be replaced with

fixed prosthesis that will improve patient comfort and masticatory

ability, maintain the health and integrity of the dental arches, in many

instances elevate the patient’s self image.

It is also possible by the use of fixed restorations, to render

supportive and long range corrective measures for the treatment of

problems related to the temporomandibular joint and its neuromuscular

system. On the other hand, with improper treatment of the occlusion it is

possible to create disharmony and damage to the stomatognathic system.

Bibliography

1) Kalkwarf K.L., Krejci R.F., Pao Y.C. : Effect of root

resorption on periodontal support. J.P.D. 1986; 56: 317-319.

2) Malone W.F.P., Koth D.L., Cavazos E. : Tylman’s theory

of practice of fixed prosthodontics. 8th Ed., Ishiyaku publications,

1977.

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3) Markley M.R. : Broken-stress principle and design in

fixed prosthesis. J.P.D., 1951; 1: 416-423.

4) Reynolds J.M. : Abutment selection for fixed

prosthodontics. J.P.D., 1968; 19: 483-488.

5) Rosenstiel R.F., Land M.F., Fujimoto J. : Contemporary

fixed prosthodontics. 1st Ed., Mosby Publications, 1988.

6) Shillingburg H.T., Hobo S., Whisett L.D., Jacobi R.,

Brackett S.E. : Fundamentals of fixed prosthodontics, 3rd Ed.,

Quintessence Publication, 1997.

7) Sutherland J.K., Holland G.A. : A photoelastic analysis of

the stress distribution in bone supporting fixed partial denture of

rigid and non-rigid designs. J.P.D., 1980; 44: 616-23.

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