CASE BASED QUESTIONS

CASE BASED QUESTIONSIMPLANTSQUESTION ONE Osseointegration implies :A. The process of inserting implants in boneB.Integration of the bone and implant with fibrous tissue between then C. At least some direct contact of living bone and the surface of the impact at the light microscopic level of magnificationD. None of the above

Answer - CDefinitionsGlossary of Prosthodontic Terms-8 The apparent direct attachment or connection of osseous tissue to an inert, alloplastic material without intervening connective tissue.

American Academy of Implant Dentistry (AAID)Osseointegration is an exact relation between normal and remodeled bone and an implant surface without interposition of non-bone or connective tissue.

3BranemarkOsseointegration is the direct structural and functional connection between the ordered lining bone and the surface of the load carrying implant.

Schroeder (1976)- Clinical DefinitionAnkylosis of the implant bone interface

4Fibro-osseous integration Fibro-osseous integration refers to a presence of connective tissue between the implant and bone.

In this theory, collagen fibers functions similar to Sharpeys fibers found in natural dentition.

The fibers affect bone remodeling where tension is created under optimal loading conditions.

5Theory of osseointegrationAccording to Branemark a direct bone to implant attachment is possible, if the implant is allowed to heal undisturbed.

Branemark histologically defined osseointegration as a direct connection between living bone and load carrying endosseous implant at the light microscopic level.

6QUESTION TWOThe force applied to the implant to check its mobility is approximately:-a.1000 gmsb. 400 gmsc.250 gmsd.500 gms

ANSWER -d

classificationEpiosteal implantDental implant structure that covers almost the entire crestal surface of the maxillary and mandibular residual alveolar bone under the soft tissue periosteum.Eg- Subperiosteal implant

It is a dental implant that receives its primary bone support by resting on the bone.new bone will grow around the implant

Subperiosteal implantCovers the almost entire crestal surface of maxillary & mandibular residual alveolar ridge. Four to six posts protruding out through gingiva and on to which the complete denture will be attached.

Endosteal Implant Extends into the basal bone for supportIt transects only one cortical plateTwo typesRoot formPlate form

In 1930 Strock placed first endosteal implant.

11Endosteal ImplantTransosteal implantsA dental implant that penetrates both cortical plates and passes through entire thickness of the alveolar bone

Parts of an implant

Body or fixture

Prosthetic abutment

Prosthetic screw

Crest module

BodyapexQUESTION THREEThe superstructure may be retained on the abutment (implant case) by the following methods except.a) Through screwsb) Through cementation c) Through adhesives. d) Through an attachment device Answer- cQUESTION FOUREndosteal impant can be:A. Root form implant only B. Plate form implant only C. Can be either root from or plate fromD. Combination of bothAnswer- CQUESTION FIVEThe transfer coping in an implant is used:A. To position an analog in the impress inserted in:B.To transfer the position of the implant in the mouth to the castC. To gain exact implant positioning D. All of the above

Answer - D

QUESTION SIXIn case of endosseous implant: A. A seal between implant surface and soft tissue is not required B. A permucosal seal of the soft tissue at the implant surface is very essential C. Whether the seal is established or not it does not really make a difference to the success D. None of the above

Answer- BCRITERIA FOR SUCCESS OF OSSEOINTEGRATION

Schnitman and Schulman, 1979Mobility less than 1mm in any directionRadiologically observed radiolucency graded but no success criterion definedBone loss no greater than one third of the vertical height of the bone Gingival inflammation amenable to treatment; absence of symptoms and infection, absence of damage to adjacent teeth, absence of paresthesia and anesthesia or violation of the mandibular canal, maxillary sinus, or floor of the nasal passageFunctional service for 5 years in 75% of patients20Albrektsson, Zarb, Worthington, and Erickson, 1986Individual unattached implant that is immobile when tested clinically

Radiograph that does not demonstrate evidence of peri-implant radiolucency

Bone loss that is less than 0.2 mm annually after the implants first year of service21Individual implant performance that is characterized by an absence of persistent and/or irreversible signs and symptoms of pain, infections, necropathies, paresthesia, or violation of the mandibular canal

In context of criteria mentioned, a success rate of 85% at the end of a 5-year observation period and 80% at the end of a 10-year observation as a minimum criterion for success

22Implant stabilityWhen an implant is placed surgically, initial stability or primary stability is a function of the bone quality, implant deign and surgical technique.

Implant placed in the dense cortical bone should have higher initial stability than in a weak cancellous boneStability is a requisite characteristic of osseointegration.

23During the osseointegration healing and maturation process , the initial stability changes with increases in bone- to implant contact and osseous remodeling.

It is unknown however what precisely constitutes adequate stability to warrant proceeding with restoration

24Rigid fixationAbsence of observed clinical mobility.First clinical criterion to be evaluated.A healthy implant moves less than 73microns appears as zero clinical mobility .The goal for root form implants should be rigid fixation and IM status 0

25QUESTION SEVENLack oosseointegration can be due to :A. Premature loading of the implant system B. Placing the implant with too much pressure C. Overheating the bone during preparation D. All of the above

Answer- D

QUESTION EIGHTWhile inserting an implant a gap is observed between the implant and the prepared site the implant will most probably:A. Fail B. Be a successC. The gap does not affect the success of the implant D. All of the above

Answer - A

Signs and symptoms of implant failure1) Horizontal mobility beyond 0.5mm or any clinically observed vertical movement under 1/2 of the surrounding bone is lost

8) SLEEPERS -Implants inserted in poor position making them useless for prosthetic support

9) Pocket depth of 5mm and increasing

10) Bleeding on probing(BOP) Index of 2 or above QUESTION NINEWhich of these is an indication for implant placement?A. Inability to wear a removable or complete dentureB. Unfavourable number and location of natural tooth abutmentsC. Single tooth loss which would necessitate preparation of undamaged teeth for fpdD. Any of the above

Answer -DQUESTION TENWhich of the following types of bone represents the worst option for implant placement?A. Type I B. Type II C. Type III D. Type IV

Answer - DBoneAn assessment of the characterstics of the recepient osseous site is criticle as the bone quality and quantity are the two of the most important factors that determine the fixture longevity Available bone Width HeightLengthAngulationCrown height/implant body ratioHeight Measured from the crest of the ridge to the opposing landmark.8-12mm heightBone height determines the crown height ,esthetics Bone augmentation

WidthWidth is measured between the facial and lingual plates at the crest

LengthMesiodistal length of the available bone in the edentulous area

AngulationDepend upon the width and density of the bone

Crown heightIts measured from the occlusal plane to the crest of the ridge It acts as a vertical cantileverDivision of available bone -Division ADimensions >5mm width>12mm heigth>7mm length6mm length20 mm crown height

Lekholm and Zarb

Quality 1: composed of homogenous compact bone. Quality 2: thick layer of compact bone surrounding a core of dense trabecular bone. Quality 3: thin layer of cortical bone surrounding dense trabecular bone of favorable strength. Quality 4: thin layer of cortical bone surrounding a core of low density trabecular bone

Misch

D1: Dense cortical boneD2: Thick dense to porous cortical bone on crest and course trabecular bone within. D3: Thin porous cortical bone on crest and fine trabecular bone within.D4: Fine trabecular bone

QUESTION ELEVENBone loss to what degree will lead to continuedproblems because the bone and soft tissues will not predictably reosseointegrate? A. Greater than 0.5-1.0 mm B. Greater than 1-2 mm C. Greater than 2-3 mm D. Greater than 3-4 mm

Answer - B Failing and failed implants

Definition- Failure process is in early stages and is reversibleClinical features- Progessive Marginal Bone loss(Saucerization)absence of mobilityperi implant infection (peri implantitis

Failure process has reached the irreversible state

Marginal bone loss reaching the apical 1/3 of implant mobility Thin peri fixtural radiolucencyFailing Implant Failed Implant QUESTION TWELVEImplants placed in the maxilla fail because of all of the following except one:A. Poor bone quality.B. Rapid resorption of bone height and width.C. Off - axis forces. D. Poorly trabeculated bone.

Answer- C

QUESTION THIRTEENResults of several studies show that the effective dose of radiation with the New CT imaging machine isA. Significantly lower than traditional CT imaging.B. Significantly higher than traditional CT imaging.C. Equal to that associated with traditional CT imaging.D. Not detectable

Answer - A D1: More than 1250 Hounsfield unitD2: 850 1250 Hounsfield unitD3: 350-850 Hounsfield unitD4: 150-350 Hounsfield unit

QUESTION FOURTEENA permucosal seal in case of a dental implant isa.Possibleb.Absolutely impossible as tissues will not stick to implant surfacec.Not necessary at alld. None of the above

Answer - a

QUESTION FIFTEENDistance between the implant and periodontal ligament of the adjacent teeth isa. 2mm b. 1mm c. 3mm d. 0.5 mmAnswer- C

QUESTION SIXTEENIdeal site for implant placement in a completely edentulous mandible is a. 1st Molar region bilaterally b.Retro molar pad area because its resistant to resorption.c. Buccal shelf area because its most suited for loading d.Mandibular interforaminal region.

Answer- D

QUESTION SEVENTEENThe New CT imaging 3G software can deliver high quality images for user-defined templates, available in all of the following ways except one:A. On paper. B. On film.C. In digital form. D. As Selenium platesAnswer- DQUESTION EIGHTEENImportant diagnostic tool for achieving accurate implant angulation is a. Diagnostic Template b. Wax- up (Diagnostic)c. Mounted casts d. Surgical Template

Answer - d

QUESTION NINETEEN Following are the signs and symptoms of failure of an implant except.a.Severe radiopacity around the implant. b.Bone loss around implant c.Pain during percussion d.Horizontal mobility > 0.5 mm.Answer- aQUESTION TWENTYThe most common types of implant in use today are:A. Subperiosteal implant B. Transosteal implant C. Endosteal implantsD.All of the above.

Answer- cQUESTION TWENTY ONEAnatomical problem associated with edentulismis :A. Width of supporting boneB. Height of supporting boneC. Thinning of mucosa and sensitivity or abrasionD. All of the above

QUESTION TWENTY TWORP-5 in implantology is a-A. Removable prosthesis completely supported by implants / teeth.B. Removable prosthesis combining implant and soft tissue support.C. Fixed prosthesis replacing natural crowns and portions of soft tissue.D. Removable prosthesis that restores anatomic crowns and portions of root of natural tooth.

Prosthodontic treatment classificationFP-1FP-2FP-3RP-4RP-5FP1 Fixed prosthesis that replaces only the crown

FP-2 - Fixed prosthesis :replaces the crown and a portion of the root

FP3 Fixed prosthesis : replacing missing crowns and gingival color and portion of the edentulous site

RP4 Removable prosthesis: Overdenture supported completely by implants

RP5 Removable prosthesis : overdenture supported by soft tissue and implant