STRAIGHT LINE

Implant COMPONENTS AND FUNCTIONPresented by :SK AZIZ IKBALDept of Prosthodontics & Crown & BridgeNORTH BENGAL DENTAL COLLEGE &HOSPITAL

What is the implant ?A dental implant ( also known as an endo-osseous implant or fixture ) :Is a surgical component that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown , ridge , denture , facial prosthesis or to act as an orthodontic anchor .

DEFINITION:A prosthetic device made of alloplastic material(s) implanted into the oral tissues beneath the mucosal or/and periosteal layer, and on/or within the bone to provide retention and support for a fixed or removable dental prosthesis, a substance that is placed into or/and upon the jaw bone to support a fixed or removable dental prosthesis.

The basis for modern dental implants is a biologic process called osseointegration ( bone-to-implant interface ) where materials, such as titanium , form an intimate bond to bone. The implant fixture is first placed, so that it is likely to osseointegrate, then a dental prosthetic is added.A variable amount of healing time is required for osseointegration before either the dental prosthetic (a crown, bridge or denture) is attached to the implant or an abutment is placed which will hold a dental prosthetic.

Implant components 1. Main components a) Fixture b)Abutment c)Superstructure2. Accessories a)Surgical -Cover Screw -Gingival Former b)Prosthetic -Implant Analogue -Impression Post

IMPLANT FIXTUREThe implant fixture is the component that is surgically placed into the bone.Also called by Implant BodyDivided into following parts- 1.Body 2.Crest Module 3.Collar

BodyMay be cylindrical or tapered cylindrical.Smooth or threaded surfaceSolid or contain holes or vents to allow bone grow throughThreaded is suitable for placement.Threads maximize initial contact with bone facilitate dissipation of stressesFunctional surface depends on- Thread pitch- Distance between the threads Thread shape- V shaped square and buttress Thread depth- Distance between the most outside thread and most inside thread

Smaller the pitch, more threads/unit length and greater surface areaGreater the thread, greater the surface area

Types of root form of implant body

Crest ModulePortion of fixture that provides a connection to the abutment or attachment.Offers resistance to axial occlusal loads and aims to provide a precise fitting for abutment on the fixtureIt consists of a platform and antirotation features.

Implant CollarSuperior part of fixture.For submerged implant it is 0.5-1mm in height, for non-submerged 3-5mm.Purpose-Allows functional remodeling of boneImproves abutment-fixture interfacePrevents exposure of surface coatings

Abutments

Abutments are the component of the implant system that screw directly into the implant .Abutments eventually support the prosthesis in screw-retained restoration , in as much as they accept the retaining screw of prosthesis .For cement retained restorations, abutments may be shaped like a conventional crown preparation .

The walls of abutments are usually smooth , polished , and straight sided .The length range from 1-10 mm In nonesthetic areas , 1-2 mm of titanium should be allowed to penetrate the soft tissue to maximize the patients ability to clean the prosthesis The choice of abutment size depends on the vertical distance between the fixture base and opposing dentition , the existing sulcular depth , and the esthetic requirements in the area being restored .For acceptable appearance , an anterior maxillary crown may require 2-3 mm of subgingival porcelain at the facial gingival margin to create the proper emergence profile and appearance , whereas fixtures in the posterior maxilla or mandible may have margin termination at or below the gingival crest .

Abutments are classified under1.Abutments for fixed prosthesis I)Definitive a. Prefabricated -Solid abutment -Hollow(two-piece abutments) b. Custom-made -Castable abutments -CAD-CAM abutments II) Provisional or temporary2.Abutments for removable prosthesis(Overdenture attachments) I) Stud attachmentsII) Bar attachmentsIII) Magnetic attachmentsIV) Telescopic attachments

IMPLANT sUperstructureThis is the prosthesis that is fabricated with the support of dental implants. They can be of following types 1.Fixed Prosthesis i) Crowns II) Bridges 2. Removable Prosthesis i) Overdenture 3. Fixed-detachable Prosthesis i) Hybrid dentures

Accessories

SurgicalI) COVER SCREWAfter surgical placement of implant, a screw is placed in the superior aspect of two-piece implants to cover the connection for abutment during healing period.So also termed as Healing Screw.During the healing phase after first stage surgery , a screw is normally placed in superior aspect of the fixture .The screw is usually low in profile to facilitate the suturing of soft tissue in two stage implant or minimize loading in the one stage implant A second stage surgery , the screw is removed and placed by subsequent components .

II) GINGIVAL FORMER- This is required only for two-stage implants. Following the second surgery to expose the implant, the cover screws are removed and gingival formers, which are available in varying heights, are placed on the implant fixture. They extend above the soft tissue into the oral cavity and form a gingival cuff around the implant.Usually placed for 2 to 5 weeks depending on the healing, following which they are removed and impression procedures are commenced.They will be replaced by the abutment in final restoration sotermed as Healing Abutment orPermucosal extensions.

Gingival former

ProstheticIMPLANT ANALOGUE A replica of the entire dental implant, not intended for human implantation. (GPT8)

This is similar to the implant fixture, but used in the model to fabricate the prosthesis in laboratory. The abutment is fitted to the analogue and prosthesis is fabricated in the laboratory. It is also termed as Implant Replica or Lab Analogue.

II) IMPRESSION COPING That component of a dental implant system used to provide a spatial relationship of an endosteal dental implant to the alveolar ridge and adjacent dentition or other structures.(GPT8)The coping is attached to the implant fixture during implant procedures using an impression screw. Following impression making the coping is removed from the implant fixture and attached to the implant analogue, to pour a cast. It is also called as Impression post, Impression pin or Transfer coping.IMPRESSION COPING

Impression coping facilitate transfer of the of intraoral location of the implant or abutment to a similar position on the laboratory cast .

Types of impression coping :Transfer ( indirect ) .Pickup ( direct ) .

Functions Of componentsIMPLANT FIXTURE: Body: It goes within bone to provide physical resistance to axial occlusal load and retains the whole structure of implant. Crest Module: Portion of fixture that provides a connection to the abutment or attachment. Offers resistance to axial occlusal loads and aims to provide a precise fitting for abutment on the fixture Implant Collar: Allows functional remodeling of bone Improves abutment-fixture interface Prevents exposure of surface coatingsABUTMENTS: It supports and/or retains a prosthesis or implant superstructure.SUPERSTRUCTURE: Either provides retaining of an overdenture with attachments or provides the framework for a fixed prosthesis.I. MAIN COMPONENTS

COVER SREW: covers the connection for abutment during healing period. Facilitates the suturing of soft tissue in two stage implant or minimize loading in the one stage implant .GINGIVAL FORMER: They extend above the soft tissue into the oral cavity and form a gingival cuff around the implant.IMPLANT ANALOGUE: It is used in the fabrication of master cast to replicate the retentive portion of the implant body or abutment.IMPRESSION COPING: It provides a spatial relationship of an endosteal dental implant to the alveolar ridge and adjacent dentition or other structures. Facilitates transfer of the of intraoral location of the implant or abutment to a similar position on the laboratory cast .

II. ACCESSORIES

Keep smilingTHANK YOUREFERENCESBouchers ProsthodonticsZarbJohn J.Manapallil SECOND EDITION CD