BASIC ASPECTS OF IMPLANT

Shilpa ShivanandIII MDS

Contents INTRODUCTION TERMINOLOGIES HISTORY RATIONALE ADVANTAGES & DISADVANTAGES INDICATIONS & CONTRAINDICATIONS CLASSIFICATION PARTS OF DENTAL IMPLANT DENTAL IMPLANT DESIGN & SURFACE TOPOGRAPHY PROPERTIES OF DENTAL IMPLANT

DIAGNOSIS & TREATMENT PLANNING

SUCCESS CRITERIA LITERATURE CONCLUSION

Systemic examinationDental examinationRadiographic examinationStudy models

Implant surface free energyChemical compositionRigidity and strength

INTRODUCTION

Dental implants designed to provide a foundation for replacement of teeth that

look, feel, and function like natural teeth.

Partial and removable prosthesis may not bring satisfactory results.

Goal of modern dentistry restore normal contour, function, comfort, esthetics, speech and health of a patient.

This leads to increased need and use of implant and implant supported prosthesis.

TERMINOLOGY

Any object or material, such as an alloplastic substance or other tissue, which partially or completely inserted or grafted into body for

therapeutic, diagnostic, prosthetic or experimental purposes.

Can be defined as a substance that is placed into the jaw to support a crown or fixed or

removable denture.Charles M Weiss

A prosthetic device or alloplastic material implanted into oral tissues beneath the

mucosal or periosteal tissues and/or within the bone to provide retention and support for fixed or removal prosthesis. Edward J Fredrickson

IMPLANT

DENTAL IMPLANT

DENTAL IMPLANT

Various implant configuration usually are found within each

system.An implant configuration is a

specific shape or size of implant A wide array of configuration is available to accommodate the anatomic variation of available

bone commonly observed in patients for implant treatment.

IMPLANT CONFIGURATION

IMPLANT SYSTEM

Different commercial systems which are available for most treatment modalities.

Replacing lost teeth with a bone-anchored device is not a new concept at all.

Archeological findings showed that the ancient Egyptian and South American civilizations already experimented with re-implanting lost teeth with hand-shaped ivory or wood substitutes.

In the 18th century lost teeth were sometimes replaced with extracted teeth of other human donors. The implantation process was probably somewhat crude and the success rates extremely low due to the strong immune reaction of the receiving individual.

HISTORY

2500 BC - Ancient Egyptians - gold ligature.

500 BC - Etruscan population - gold bands incorporating pontics.

500 BC - Phoenician population - gold wire.

300 AD - Phoenician population - Carved Ivory teeth.

600 AD - Mayan population - implantation of pieces of shell.

1911 - Greenfield – iridoplatinum basket soldered with 24 carat gold.

1943 –Dahl- subperiosteal type of implant

Late 1970s and Early 1980s - Tatum - custom blade implants of Titanium alloy

Early 1980s - Tatum - Titanium root form implant

Modern Historical Developments

The first Subperiosteal Implant was placed in 1948 by Gustav Dahl

The Endosteal Blade Implant, introduced independently in 1967 by Leonard Linkow and Ralph and Harold Roberts

After 1980s –hollow basket Core vent implant Niznick et al -Screw vent implant -Screw vent implant with Hydroxyapatite coating - Implant with titanium plasma

spray

The quantum leap in Oral Implantology was achieved in 1952 in Sweden by

PER INGVAR BRANEMARK

He founded the phenomenon of Osseointegration

Dr. Branemark's research shifted more towards the use of titanium appliances in human bone, including the use of titanium screws as bone anchors for lost teeth.

In 1982, the Toronto Conference on Osseointegration in Clinical Dentistry laid down the first parameters on what is to be considered successful implant treatment within the stringent confines of the scientific community.

RATIONALE OF DENTAL IMPLANTS

INCREASED DEMAND FOR IMPLANT-RELATED TREATMENT RESULT FROM COMBINED EFFECT OF SEVERAL FACTORS

Ageing population living longer Tooth loss related to age Consequences of fixed prosthesis failure Anatomical consequences of edentulism Poor performance of removable prosthesis Consequences of R.P.D. Psychological aspects of tooth loss and need and

desire of ageing population Predictable long term results of implant supported

prosthesis Advantages of implant supported restorations Increased public awareness

ANATOMIC PROBLEMS AND CONSEQUENCES OF EDENTULISM

-Decreased width of supporting bone -Decreased height of supporting bone -Decrease in keratinized mucosa-Prominent mylohyoid and internal oblique ridges-Prominent superior genial tubercles-Mucosal thinning with sensitivity to abrasion-Parasthesia from dehiscent mandibular canal-Lack of stimulation - decrease in trabeculae and bone density in the area.-After initial extraction of teeth, the average first year bone loss is

more than 4mm in height and 30% in crestal bone width. Although the rate of bone loss is slower after first year,

the bone loss is continuous throughout life,

ANATOMIC CONSEQUENCES ON SOFT TISSUE STRUCTURE

Effect on attached gingiva - As soon as the bone loses width and height, the zone of attached gingiva starts decreasing.

Either the attached tissues are completely absent or a very thin attached tissue may lie over the advanced atrophic mandible, the gingiva is very prone to abrasion caused by overlying prosthesis

The size of tongue also increases to fill up the space previously occupied by teeth. tongue becomes more active in mastication

Unfavorable high muscle attachments and hypermobile tissue complicate the situation.

Conditions such as hypertension, diabetes, anemia and nutritional disorders have a deleterious effect in elderly.

Decreased neuromuscular control

Aesthetic consequences

Decreased facial height Loss of labiomental angle Deepening of vertical lines in lip and face Chin rotates forward and Ptosis of mentalis muscle attachment— gives a prognathic appearance called “witch's chin" Decreased horizontal labial angle of lip-makes patient look unhappy Loss of tone in muscles of facial expression Thinning of vermillion border of the lips from loss of muscle tone Deepening of nasolabial groove Increase in columella-philtrum angle Increased length of maxillary lip, so less teeth show at rest and smiling Ptosis of buccinator muscle attachment—leads to jowls at side of face

Psychological effect of tooth loss

Dissatisfaction with appearance, low self-esteem and avoidance of social contact

Loss of self-confidence Difficulty in speech, phonation or pronunciation of specific words. 88% claim some difficulty with speech, and 25% claim significant

problems A report shows that in the United States :- More than $200

million each year spent on denture adhesive to decrease embarrassment

approximately 80% of patients treated with implant supported prosthesis showed that their overall psychological health improved in comparison with their previous removable prosthesis.

RATIONALE

Implant dentistry is a boon for restoration of missing teeth.

What makes implant

dentistry unique is the

ability to achieve

replacement of teeth

regardless of atrophy,

disease, or injury to the

stomatognathic system

It overcomes many

disadvantages of other conventional

methods of

restoration ie., removable

and fixed prosthesis.

Why are Implants preferred over Dentures and Bridges ?

Stability

Grinding of adjacent healthy teeth

Chewing efficiency

Comfort /artificial feeling

Protection of the jawbone

Eating habits

ADVANTAGES OF IMPLANT- SUPPORTED PROSTHESIS

Maintain bone height & width Restore and maintain occlusal

vertical dimension Maintain facial esthetics Improve esthetics Improve phonetics Improve occlusion Increase prosthesis success Improve masticatory

performance/maintain muscles of mastication and facial expression

• Reduced size of prosthesis• Improve stability and retention

of removable prosthesis• Increase survival times of

prostheses • There is no need to alter

adjacent teeth• More permanent replacement • Improve psychological health

DISADVANTAGES OF DENTAL IMPLANTS

Very expensive.

Cannot be used in medically compromised patients who cannot undergo surgery.

Longer duration of treatment and tedious fabrication procedures.

Requires a lot of patient co-operation because of repeated recall visits for after care is essential

INDICATIONS

Severe morphologic compromise of denture supporting areas that significantly undermine denture retention.

Poor oral muscular coordination. Para functional habits leading to recurrent soreness and instability of

prosthesis. Unrealistic prosthodontic expectations Active or hyperactive gag reflexes elicited by removable prosthesis. Psychological inability to wear a removable prosthesis, even if

adequate denture retention and stability is present. Unfavorable number and location of potential abutments in a residual

dentition. Single tooth loss to avoid involving neighboring tooth as abutments. Esthetic zone preserve interdental diastemas

ABSOLUTE CONTRAINDICATIONS

1. Recent myocardial infarction2. Valvular prosthesis3. Severe renal disease4. Uncontrolled & treatment

resistant diabetes5. Advanced & untreated

osteoporosis 6. Treatment resistant

osteomalacia7. Uncontrolled endocrine

gland disease8. Advanced & uncontrolled

acquired immunodeficiency syndrome

• Systemic hematological disorders

• Irradiation of the jaw• Liver and kidney disorders• Osteoporosis/ low bone

mineral content• Local pathology

RELATIVE CONTRAINDICATIONS

CLASSIFICATION

Classification of implants by Charles. A. Babbush There are five main types:

1.ENDOSTEAL IMPLANT An implant which is placed into the alveolar bone and/

or basal bone of the mandible or maxilla Transects only one corticle plate Most commonly used

Blade implant Ramus frame implant

Root form implant

It consists of thin plates in the form of blade embedded into the bone

Designed to mimic the shape of the tooth For directional load

distribution

Horse shoe shaped stainless steel device Inserted from one retromolar pad to other

2. SUBPERIOSTEAL IMPLANT Placed directly beneath the periosteum overlying the bony cortex Do not penetrate into the jawbone. Consists of non-Osseo integrated framework that rests on the surface of the jaw or beneath the mucoperiosteum. Can be bilateral or unilateral

3. TRANSOSTEAL IMPLANT Other names- staple bone implant Mandibular staple implant Transmandibular implant Combines the subperiosteal and endosteal components Penetrates both cortical plates very similar to a nut and bolt arrangement Used in mandibles only penetrate the entire jaw to emerge opposite the entry site, usually

at the bottom of the chin.

4. INTRAMUCOSAL IMPLANTS

Inserted into oral mucosa Mucosa is used as attachment site for metal inserts

•Described by Dr CHARLES WIESS•Complete encapsulation of implant with soft tissue•Soft tissue interface could resemble highly vascular periodontal fibers of natural dentition

•Described by BRANEMARK•Direct contact between bone & surface of loaded implant•Bio active materials that stimulate formation of bone are used

Cylindrical dental implants• In the form of cylinder• Depends on coating or surface conditioning to provide

microscopic retension & bonding to bone• pushed or tapped into prepared bone site• Straight, tapered or conical

Threaded dental implants• The surface is threaded, to increase surface area of

implant• This results in distribution of forces over greater peri-

implant bone volume

Perforated dental implants• are made of inert micro porous membrane material

(mixture of cellulose acetate) in intimate contact with & supported by layer of perforated metallic sheet material (pure titanium)

Plateau dental implant• Plateau shaped implant with sloping shoulder

Solid dental implant• They are of circular cross section without vent or hollow in the body

Vented dental implant• It is hydroxyapetite coated cylinder with patented vertical groove connecting to apical vents designed to facilitate seating and allow bone in growth to prevent rotation

Hollow dental implantHollow design in apical portionSystematically arranged perforations along sides of implantIncreased anchoring surface

Smooth surface implant•Has very smooth surface•Surface is smoothened to prevent microbial plaque retention

Machined surface implant•Surface of implant is machined for better anchorage of implant to bone

Textured surface implant•Have increased rough surface area to which bone can bond

Coated surface implant•Implant is covered with porous coating such as titanium & hydroxyapatite

Metallic implants• Most popular metal in use today is titanium• Other metals used- stainless steel, cobalt chromium molybdenum alloy & vitallium

ceramic/ ceramic coated implants• Ceramic used to coat metallic implants to produce bio active surface• Can be either plasma sprayed or coated • Non reactive ceramic materials are also present

Polymeric implants•Made of polymethylmethacrylate & polytetrafluoroethylene•Used only as adjuncts stress distributers along with implant rather than implants by themselves

Carbon implants•Made of carbon with stainless steel•Modulus of elasticity equivalent to bone & dentine•Brittleness leads to fracture

• Depending on the materials used: Metallic implants [titanium, titanium alloy, cobalt chromium molybdenum

alloy]

Non- metallic implants [ceramics, carbon]• According to loading

• Immediate(<2weeks)• Early(2weeks -2mts)• Delayed (>3mts)

• According to method of placement• Tapping system• Threading system

Based on the surface

Machined surface Sand blasted Acid etched HA coating Plasma spray Bioactive surface Oxidized surface Combination of one/more

PARTS OF DENTAL IMPLANT

Implant Body or Fixture: the component that is placed within the bone during first stage of surgery.

Abutment Is the part of implant, which resembles a prepared tooth, and is designed to be screwed into the implant body via Abutment screwIt is the primary component, which provides retention to the prosthesis

crown :replicate the original teeth to provide a biting surface and aesthetic appearance

Crown: Material Used: Porcelains (metal supported or metal free) or metal (normally gold)

Abutment: Materials Used: Titanium.

Implant Body or Fixture: Materials Used: Titanium & titanium oxide

OTHER IMPLANT COMPONENTS

Healing ScrewDuring the healing phase, this screw is normally placed in the superior surface of the body.functions -Facilitates the suturing of soft tissue over the edge of the implant.Healing Capsdome-shaped screws. Length ranges from 2-10mm.Project through the soft tissue into the oral cavityFunction -prevent overgrowth of tissues around the implant during healing phase.Impression posts/coping:Is a small stem that facilitates the transfer of the intraoral location (of the implant or the abutment) to a similar position on the cast.They are screwed into implant body during impression making.

Analogue or Implant ReplicaAnalogues are used by laboratory technicians to replicate implants and their position in a patient’s mouth.The analogue,screwed onto the impression coping, isset into the plaster model during casting

Components of a dental implant.mp4

BASIC ASPECTS OF IMPLANT

Shilpa ShivanandIII MDS

Contents INTRODUCTION TERMINOLOGIES HISTORY RATIONALE ADVANTAGES & DISADVANTAGES INDICATIONS & CONTRAINDICATIONS CLASSIFICATION PARTS OF DENTAL IMPLANT DENTAL IMPLANT DESIGN & SURFACE TOPOGRAPHY PROPERTIES OF DENTAL IMPLANT

DIAGNOSIS & TREATMENT PLANNING

SUCCESS CRITERIA LITERATURE CONCLUSION

Systemic examinationDental examinationRadiographic examinationStudy models

Implant surface free energyChemical compositionRigidity and strength

IMPLANT SURFACE TOPOGRAPHY

Roughness parameters0.04 –0.4 m - smooth 0.5 – 1.0 m – minimally rough 1.0 –2.0 m – moderately rough 2.0 m – rough

Wennerberg (1996) – Moderately rough implants developed the best bone fixation.

In vivo studies Smooth surface < 0.2 m will – dislodged fibrin clot- no bone

cell adhesion clinical failure. Moderately rough surface- more bone in contact with

implant better osseointegration.

METHODS TO ALTER THE SURFACE TEXTURE

ADDITIVE SURFACE TREATMENT

• Titanium plasma spraying and HA coating

ABRASIVE SURFACE TREATMENT

• Grit blasting• Acid etching • Grit blasting with acid etching

MODIFIED SURFACE TREATMENT

• Oxidized surface treatment• Laser treatment• Ion implantation

ADDITIVE SURFACE TREATMENT

ADVANTAGES of TPS & HA COATINGSteinemann(1988) Tetsch(1991)- Titanium Plasma Sprayed

coating provide 6-10 times increase surface area.HA coating can lower the corrosion rate of the same substrate

alloys. HA coatings has been credited with enabling to obtain improved

bone to implant attachment compared with machined surface.

the first rough titanium surface introduced by this procedureCoated with titanium powder particles in the form of titanium hydride

Titanium plasma sprayed coating (TPS)

CERAMIC AND CERAMIC COATED IMPLANTS Ceramic materials are used to coat metallic implants to produce an ionic ceramic surface, which is thermodynamically stable and hydrophilic, thereby producing a high strength attachment to bone and surrounding tissues. These ceramic can either be plasma sprayed or coated on to the metal implant to produce bio-active surface.

ADDITIVE SURFACE TREATMENT

Aluminum oxide (Al2O3) is used as the gold standard for ceramic implants because of its inertness with no evidence of ion release or immune reaction in vivo. Zirconia (ZrO2) has also demonstrated a high degree of inertness.

THE TÜBINGEN IMPLANT OF ALUMINUM OXIDE HAS SPECIFIC MICRO-IRREGULARITIES ON THE SURFACE,

CLAIMED TO ALLOW BONE INGROWTH.

ABRASIVE SURFACE TREATMENT BLASTING Blasting with particles of various diameters is one of the frequently

used method of surface alteration. In this approach, the implant surface is bombarded with particles of

aluminum oxide (Al2O3) or titanium oxide (TiO2), and by abrasion, a rough surface is produced with irregular pits and depressions.

Roughness depends on particle size, time of blasting, pressure, and distance from the source of particles to the implant surface.

Blasting a smooth Ti surface with Al2 O3 particles of 25 µm, 75 µm, or 250 µm produces surfaces with roughness values of 1.16 to 1.20, 1.43, and 1.94 to 2.20, respectively.

SAND BLASTED IMPLANT

SAND BLASTING & ACID ETCHING

The objective Sand blasting – surface roughness Acid etching – cleaning

Wennerberg et al 1996 - superior bone fixation and bone adaptation

Lima YG et al (2000), Orsini Z et al (2000).Acid etching with NaOH, Aq. Nitric acid, hydrofluoric acid – better cell attachment. Acid etching with 1% HF and 30% NO3 after sand blasting - increase in osseointegration by removal of aluminium particles (cleaning).

•Porous sintered surfaces are produced when spherical powders of metallic or ceramic material becomes a coherent mass with the metallic core of the implant body.• Lack of sharp edges is what distinguishes these from rough surfaces. •Porous surfaces are characterized by pore size, pore shape, pore volume, and pore depth, which are affected by the size of spherical particles and the temperature and pressure conditions of the sintering chamber.

POROUS SURFACE

surface of a porous titanium alloy implant

fibroblasts cultured for 24 hours on the surface of a porous titanium

alloy implant.

POROUS SURFACE: ADVANTAGES

1. secure, 3-D interlocking interface with bone.2. Predictable and minimal crestal bone remodelling3. Greater surgical options with shorter implant lengths.4. Shorter initial healing times5. Porous coating implants provide the space, volume for

cell migration and attachment, thus support contact osteogenesis.

.

LASER INDUCED SURFACE ROUGHENING Eximer laser – “Used to create roughness”Advantage- Regularly oriented surface roughness configuration compared to TPS coating and sandblasting

SEM x 300

SEM x 300SEM x 70

IMPLANT SURFACE CHEMICAL COMPOSITION

Titanium - very reactive metal that oxidizes within nanoseconds

when exposed to air.

Passive oxide layer of the titanium -very resistant to corrosion.

All titanium oxides have dielectric constants, which are higher

than for most other oxides - tendency to adsorb biomolecules.

RIGIDITY & STRENGTH OF ESTABLISHED BONE-TO- IMPLANT INTERFACE

Bone - limited elasticity,

Elasticity modulus of 10GPa for the cortex and 1-5 GPa/m2 for

cancellous bone. Thus at the interface between implants and

bone, even when a strong apposition of lamellar bone has

occurred, differences in elasticity are present.

Both the primary and secondary stability of an implant determine

its success and survival.

Primary stability -achieved at surgery.

- Depends on the bone quality and available volume, the relation between drill and implant diameter, and the implant geometry, quantity of bone-to-implant contact area.

Dense cortical bone -symphyseal area -guarantees a rigid primary fixation.

- Questionable with an eggshell cortex in the maxillary tuberosity.

During the first weeks of one-stage implants - decreased rigidity - Subsequently rigidity increases and continues to increases for years.

when a prosthesis is installed immediately (1day) or early ( in 1-2 weeks), care must be taken to control overload.

Overload - improper superstructure designs or parafunctional habits - cause microstrains and microfractures - bone loss at the interface to fibrous inflammatory tissue,

Lack of load can also be detrimental and can lead to cortical bone resorption.

The use of finite element analysis (FEA) do provide some insight on stress concentrations and their relation to implant geometry and rigidity and the prosthetic superstructures.

Assessment of implant biomechanics –by noninvasive devices such as the Periotest and the Ostell. These tests reflect the rigidity of the bone-to-implant interface.

The Periotest projects a rod against the implant or abutment using a magnetic pulse at a certain speed. The apparatus measures the deceleration time needed before the rod comes to a standstill.

This is transformed in an arbitrary unit which reflects the rigidity of the bone-to-implant continuum.

Values should be below + 7, the minimum with the most rigid being – 8.

The resonance frequency analysis (RFA) offers an alternative measurement. With the Ostell device, overall resonance frequency can be measured at the implant surface.

Primary stability -frequency range of 6-9 kHz- higher values in mandible. Arbitrary values which should not exceed 56,which indicates a level of bone support that is consistent with osseointegration.

•When the surface roughness is microscopic-bone adaptation to micro topography will increase the shear strength needed to fracture bone from the surface to a level that is greater than a turned surface but less than that of a plasma sprayed surface ( Klokkevold et 2001)

•Pull out tests- Screw implants- Cannot asses the biologic adhesion force

•Pull off tests- non retentive surface is detached from the underlying bone

PRETREATMENT EVALUATION

Chief complaintMedical history MEDICAL HISTORY – MEDICATIONS,ALLERGIES SOCIAL HISTORY , FAMILY HISTORYDental history A thorough clinical assessment should be undertaken for

every patient before undergoing therapy.

Chief complaint

Problem or concern in the patient’s own wordsPatients goal of treatmentHow realistic are the patients expectationsHistory of present illness If the patient has been referred…the extent of the

desired treatment has to be defined, referring dentist informed of the expectations regarding the outcome.

Medical history

Cardiovascular systemRespiratory systemCentral nervous systemDigestive systemEndocrine systemHematopoietic systemGenitourinary system

AllergiesBones & jointsNeoplasmMenopausePregnancyMedications

Medical history

Gender..no influence on the outcome.

Women after menopause more prone to develop osteoporotic conditions.

(Lekholm et al. 1994, Friberg et al. 1997, Sennerby & Rasmusson 2001)

Medical history

Age..no influence.. In osseointegration..implants become bone anchored both in young

(Thilander et al. 1994)

& elderly individuals (Kondell et al. 1988, Jemt

1993)Still…elderly patients more susceptible to

infections… slow healing .. (Sermerby & Rasmusson

2001)

Medical history

Growing individuals… rather react like ankylotic teeth...infra-occlusion

(Oilman 1994)

Not the chronological age but dental/skeletal maturation considered in adolescents.

(Thilander et al. 1994)

Radiographs of the hand bones..

Psychosocial reasons … (Koch et

al. 1996)

Medical history

In young adults requiring tooth replacement, implant placement should be postponed after the age of 25 due to the prolonged changes in anterior face height & posterior rotation of the mandible.

Jemt T 2007

Dental history

A history of recurrent or frequent abscesses…indicate susceptibility to infections or diabetes.

Presence of a number of restorations, compliance with previous dental recommendations, the patient’s current oral hygiene practices noted.

The individuals past experience with surgery & prosthetics, or any dissatisfaction with past treatment should be discussed.

Extra-oral parameters

1. Facial proportions2. Facial symmetry 3. Need for lip & cheek support4. Facial skeletal classification5. Intermaxillary relation6. Incisal edge position of the maxillary centrals &

occlusal plane7. Neurologic test to serve as a baseline assessment

in case of intraoperative nerve lesions8. TMJ movement & function

Systemic examination

Baseline vital signs

- Blood pressure- Pulse- Respiration- temperature

INTRA ORAL EXAMINATION

Amount of resorption of edentulous ridgeSize & shape of edentulous ridgeQuality of tissueInter occlusal spaceJaw relationshipFloor of mouthAmount of hard tissueSoft tissue pathologyPatients oral hygiene

BONE EVALUATION

Available bone :is the amount of bone in the edentulous area considered for implantation

it is measured in :• width • height• length• angulation• crown : implant

Maxillary canine eminance -- greater height of alveloar bone than max ant or post region

Mand canine & premolar reduced height than anterior anterior loop of mandibular canal

Available bone angulation : Ideally it is aligned with the forces of occlusion & is parallel to the long axis of prosthodontic restoration

angulation of force b / w the body & the abutment of an implant is correlated with the width of the bone. wider ridge -30degree angulation.

The narrow width ridge- requires a narrower design root form implant which cause greater crestal stress – so the acceptable angulation is 20

DIVISIONS OF AVAILABLE BONE By Mish & Judy (1990) Resorption pattern

A. abundant bone

B. Adequate bone height, but reduced bone widthB-w – require bone graftingC-w - Advanced bone width reductionC-h - Advanced bone height loss

D - is severe atrophy

LEKHOLM & ZARB 1985

Four Mish bone densities

Diagnostic records

• Photographs• Study models• Radiographs• Diagnostic waxup

PhotographsIntra oral & Extra oral photographs should be taken pre-operatively, intra-operatively & post- operatively

Diagnostic cast•Assist in implant site selection &angulation requirements during surgical phase • surgical template • one set – permanent record – dentolegal cases • used for presentations to motivate the patient acceptance of the proposed treatment

RADIOGRAPHIC EXAMINATION

OBJECTIVE

Phase I pre surgical implant imaging

Phase II surgical and intra operative implant imaging

Phase III post prosthetic implant imaging

• Identify disease•Determine bone quantity• Determine bone density•  Identify critical structures at the proposed implant regions • Determine the optimum position of implant • Placement relative to occlusal loads

IMAGING MODALITIES

Periapical radiographyPanoramic radiographyOcclusal radiography Cephalometric radiography.TomographyComputed tomographyInteractive computed tomographyMagnetic resonance imaging

Interactive computed tomography

Interactive CT in conjunction with a surgical guide stent, can

help guide dental implant placement into the ideal position with respect to function and esthetics.

There are 3 basic views available on the Simplant™ screen and a three dimensional view

The Panoramic view is similar to a normal two dimensional panoramic

view

Simplant

The axial view offers a perspective from a coronal/apical direction.

There is a cross sectional view that allows a mesial/distal perspective of the arch.

Simplant 9.2 is new version of software

Enhanced treatment plan and reduced risk of errors.

All three of these views correlate to each other

When a marker is moved on one view it corresponds to the other two views. The final perspective is a 3 dimensional view

The 3 dimensional view allows the clinician to check for parallelism of implants.

Radiographic stent

Radiographic stent - (can double as surgical stent)Acrylic stent with lead beads or ball -bearings

(5mm) placed in proposed fixture locations, allows more accurate radiographic interpretation

Edentulous jaw

Clear Acrylic Stent

RPD

Impression

Place Metal Tubes in the Stent

Make a Radiograph

Stent for surgery

Guidelines Inter Implant Distance:-

Least 1mm of bone on all the 4 sides.

1mm 1.0-1.5

mm

1mm

1mm

1mm

1mm

Implants With Natural Teeth 0.5mm for PDL Space on either sides 2 - 2.5mm space: soft tissue

Edentulous space dimensions:

1mm

1.5-2.0mm

0.5mm

7-8mm

Inter-arch space:

Sufficient inter-arch space is necessary

Rule: For fixed implant-supported

prosthesis 7 mm - in the posterior region 8-10 mm - in the anterior areas.

An implant-retained removable prosthesis requires at least 12 mm.

8-10mm

12 mm

7mm

Adjacent teeth:

Rule: At least 7 mm between two

adjacent teeth.

Adjacent teeth must be infection free:

all restorative, periodontal, and endodontic procedures should be completed prior to implant planning.

7 mm

7 mm

Esthetic evaluation:

Smile line analysis is critical for maxillary anterior implants

Use of stone cast models:

The final step of clinical assessment …impressions for stone cast models

Used during treatment planning….surgical position & direction stents.

Diagnostic casts & working models provide information about the existing oral conditions not apparent during the oral examination.

Helps design optimal occlusal contact.

Selection of the implant design Diagnosis & fabrication of implant positioning

devices.

Evaluate prosthodontic criteria in the absence of the patient:

Occlusal centric relation position, including premature occlusal contacts

Edentulous ridge relationships to adjacent teeth & opposing arches.

Position of potential natural abutments including inclination, rotation, extrusion, spacing, parallelism, & esthetic considerations

Wax-up

The diagnostic wax-up on the working models provides a vision of the emergence & position of the restoration.

RIDGE MAPPING

Evaluating the bucco-lingual bony contour by using a bone probing technique & a measuring guide.

Measurement procedure to ensure that the diameter of an endosseous screw implant does not exceed the dimensions of available bone.

The Wilson Bone Caliper

Adaptable for measuring in both anterior & posterior regions of the mandible & maxilla.

The millimeter scale can be read from either side.

Ridge mapping technique:

Measurement of crestal width.

2 measurements taken at each implant site: one at the level of the ridge crest & the other at a point approximately 7 mm vertically.

Perio probe or an Endo file with

stopper

Trim the cast

Transfer the marks to the cast Mark and section

Assess bone density ??

Bone density CADIA Kodak densitometric software

Primary implant stability

Initial stability that is achieved at surgery

Prerequisite for implant survival

• Branemark et al. 1977; Adell et al. 1981; Albrektsson et al. 1981; Meredith 1998; LioubavinaHack et al. 2006

Prevents the formation of a connective tissue layer between implant and bone, thus ensuring bone healing

Prosthetic Options

Depending On The Treatment Options (Misch in 1989 )

FP- 1: replaces only the crown; looks like a natural tooth.

FP- 2: replaces the crown and a portion of the root; crown contour appears normal in the occlusal half but is elongated or hypercontoured in the gingival half.

FP- 3: replaces missing crowns and gingival color and portion of the edentulous site; prosthesis most often uses denture teeth and acrylic, but may be made of porcelain, or metal.

RP-4: overdenture supported completely by implant. RP-5: overdenture supported by both soft tissue and implant.

Success of implants…criteria Ideal clinical conditions for natural teeth include many factors, several

ofwhich apply to dental implants:

PAIN

• Absence of pain is a primary implant criterion of evaluation

• Presence of pain almost always requires removal of the implant, even in the absence of mobility

MOBILITY

• Rigid fixation indicates an absence of clinical mobility of an implant under 1 to 500 g vertical or horizontal forces.

• Implants with less than 0.5 mm horizontal movement may return to rigid fixation and zero mobility

PROBING DEPTH

• Stable rigid fixated implants have reported pocket depths of 2 to 6 mm

• Partially edentulous patients have consistently greater probing-depths around implants than around teeth

PAPILLA BLEEDING INDEX

• Most common sulcus bleeding gingival index used for implants is the Loe and Silness gingival index

BONE LOSS

• Initial bone loss around implant during the first few years result of excessive stress at the crestal implant-bone interface

• Stress factors such as occlusal forces, parafunction should be evaluated and reduced when initial bone loss is observed.

Literature…..

Conclusion

The increasing number of malpractice lawsuits means a thorough evaluation of patient history and an awareness of the risk of treatment failure and complications is required as implant treatment outcomes are not as predictable as that of the conventional therapies with fixed (FDP) or removable dental prostheses (RDP), particularly in circumstances where aesthetic considerations are the overriding concern.

The application of a systematic patient assessment and a straightforward diagnostic planning procedure facilitates an optimal treatment recommendation and helps to avoid failures and complications.

References

Carranza’s clinical periodontology: 10th Ed.Clinical periodontology and implant dentistry: Jan

Lindhe- 4th Ed.Contemporary implant dentistry: Carl E Misch.Misch CE, Misch FD. Diagnostic casts, preimplant

prosthodontics, treatment prosthesis surgical templates In Dental Implant Prosthetics. Mosby; 2005.

Bjarni E. Pjetursson et al. Improvements in Implant Dentistry over the Last Decade: Comparison of Survival and Complication Rates in Older and Newer Publications. Int J Oral Maxillofac Implants 2014;29(suppl):308–324.

Perio 2000 vol 66;2014Pjetursson BE, Bragger U, Lang NP, Zwahlen M.

Comparison of survival and complication rates of tooth supported fixed dental prostheses (FDPs) and implant supported FDPs and single crowns (SCs).Clin. Oral Impl. Res. 18 (Suppl. 3), 2007; 97–113.

Ranya Faraj Elemam and Iain Pretty. Comparison of the Success Rate of Endodontic Treatment and Implant Treatment. ISRN Dentistry Volume 2011.