u Prosthodontic prosedure-2.txt

Prosthodontic Procedures in Implant Dentistry Pakhshan Ghaderi DDS,MSc Assistant Professor Department of Prosthodontics NYU College of Dentistry Lecture Objectives 1-Learn the nomenclature, components and armamentarium in implant dentistry Learn the basic concepts in implant dentistry Learn the...

Prosthodontic Procedures in Implant Dentistry Pakhshan Ghaderi DDS,MSc Assistant Professor Department of Prosthodontics NYU College of Dentistry Lecture Objectives 1-Learn the nomenclature, components and armamentarium in implant dentistry Learn the basic concepts in implant dentistry Learn the clinical steps involved in fabricating a single implant-supported crown Recognize and differentiate different types of implant restorations: Cement- retained versus screw- retained Partially edentulous patient Implant Supported prosthesis for partially edentulous patient Fixed Retention systems for fix implant supported prostheses can be obtained via screw retaining or through cementation. These two options gave distinct advantages and disadvantages in clinical practice Cement Retained Screw Retained Fully edentulous patient Fixed Implant Supported prosthesis for edentulous patient Implant Supported prosthesis for fully edentulous patient Removable: Over Denture Prosthetic Related Terminology Tissue level implant vs Bone level Implant The difference between the two is that neck of bone level ( implant-abutment junction ) stayed at the level of bone, but in the Tissue Level neck of the implant ( implantabutment junction )is moved 2-3 mm coronally, near gingival margin. Tissue level implant vs Bone level Implant • Graphic demonstrate the difference between the restorative interface of a tissue level and bone level implant. This shows how the bone level emergence profile can can be modified and the tissue level is predetermined • The built-in emergence profile: the transmucosal part can achieve an optimal emergence profile for posterior restoration • Lower susceptibility to peri-implant disease Transgingival collar that pass through gingiva Abutment A dental implant abutment is formally defined as “that portion of implant compartment that serves to support and/or retain a prosthesis”. A dental implant provide a secure platform for a prosthesis . Abutments are connecting pieces that join the prosthesis to the implants. Abutment Implant abutment types • Implant abutments can be either standard (prefabricated)or customized . • The use of a standard abutment is indicated if the implant is placed in an almost ideal prosthetic position. The advantages of standard abutments are time efficiency in the overall treatment and therefore shortening of the technical manufacturing time. • Customizing an abutment gives the clinician the freedom to individualize its position and angulation. to individualize the emergence profile and future crown margin position and can be used in Complicated situation that prefabricated abutment does not meet all the criteria for esthetic and function of final restoration. Individualization may be achieved using CAD/CAM technology, gold abutments produced with traditional lost-wax casting methods. Abutment Method of fabrication a implant supported crown: Screw-retained crown vs Cement-retained crown A dental implant provide a secure platform for a prosthesis . Abutments are connecting pieces that join the prosthesis to the implants Retention systems for fix implant supported prostheses can be obtained via screw retaining or through cementation. • In Cement-retained implant supported crown: abutment is screwed on implant by abutment-screw and crown get cemented on the abutment(a system in which abutment is placed over implant and prosthesis placed over abutment). Crown get retention via cement • In Screw-retained implant supported crown: Crown is built up on abutment and become one piece and the whole piece get screwed by abutment screw. Screwretained restorations are designed to be screwed directly on to the implant.(a system in which abutment is a part of the prosthesis ). crown get retention via screw Cement Retained Screw Retained Abutment Screw-retained crown vs Cement-retained crown These two options gave distinct advantages and disadvantages in clinical practice. Comparing all the advantage and disadvantage of these two design would be a very lengthy discussion , but each of them has a contraindication that can not be used. 1-when angulation of implant is not correct screw retained can not be used: In screw retained implant supported crown access hole for screw is visible on the crown and the screw channel is directed in extension of the implant axis, therefor in any situation that because of implant angulation ,access hole compromising the esthetic ,screw retained can not be used and the only option is cement retained 2-when interocclusal space is restricted Cement retained can not be used: In Cement retained implant supported crown , for crown to get enough retention ,the abutment should be more than 4 mm long ,and 3 mm space is for crown itself. If interocclusal space (crown height space) is not enough (less than 7mm),cement retained prosthesis can not be used and the only option is screw-retained Abutment Screw-retained crown vs Cement-retained crown Cover Screw Healing Abutment Cover Screws are flat . For subgingival healing (healing under closed mucoperiosteal flap) the use of a Cover screw is needed. A second surgical procedure is required for uncovering the implant and insertion of the desired Healing abutment for tissue engineering .With screw driver can be screwed Healing Abutments is offered in different height. Healing abutments enabling soft-tissue sculpting during transgingival healing. After the soft-tissue healing phase they are replaced with the appropriate temporary or final restoration. With screw driver can be screwed Implant/abutment Interface The implant abutment interface is corresponds to the connection site where the implant body connects to the abutment and restoration, so its clinical abilities are vital to successful outcomes, especially as implant failure is now known to be strongly related to how the restorative phase is managed. Implant/abutment Interface Primary determinants of • Joint stability between abutment and implant • Joint strength between abutment and implant • Locational & rotational stability Prosthetic stability ( Paul P. Binon 2000) Implant/abutment interface’s configurations • Interface Geometry = Connection • Interface Size = Prosthetic Platform • Connection Screw = Screw Connection Historically, the first implant abutment connection interface was the external hexagon (or hex) configuration introduced by Branemark. This design became the standard for that period, Albrektsson et al. (1983) recommended Standard Implant with this characteristics: Threaded implant Machine Surface External Hex Regular Platform (RP ∅ 4.1 mm interface) Connection External connection • Many clinical studies reported abutment screw loosening as a frequent problem related to single tooth -implants supported crowns with branemark design. • In a prospective study, 107 single-tooth implant restorations supported by Brånemark implants were followed up for 5 years. It was reported that 26% of the abutment screws were retightened during the first year. • Short , narrow external geometry ,limited engagement cause lake of joint stability under lateral force , developing micromovement and micro gap and ultimately Screw loosening Connection Internal connection concept A few years after Brånemark’s implant with external connection Dr.Schroeder (University of Bern, Switzerland)came out with an implant, known as ITI Bonefit or (later) Straumann with Internal connection . Considering the disadvantages of external connection and success of ITI internal connection, This was the start of shift from external to internal connection. Connection External vs Internal • Two basic implant connection geometries are available: External(A) and Internal(B) connections. • The distinctive factor that separates the two groups is the presence or absence of a geometric feature that extends above the coronal surface of the implant • External connections usually have an external hexagon on the implant platform, whereas internal connections geometry is inside the platform which base on their shape can be divided into internal Hexagons, internal Octagons, internal Tri-lobe and internal taper connections . A B Connection New interface design Since the introduction of the internal connection concept, further design enhancements have been made in an attempt to enhance the implant/abutment connection: • To improve connection stability throughout function & placement • To simplify the armamentarium necessary for the clinician to complete the restoration Connection Different abutment with different connections . • The preciseness of fit in this engagement design provide stability and a screw tightens them together . • The force applied in the tightening (torque) is only valid if the machining and adaptation degree between abutment and implant were proper because high levels of tightening torque would not produce the desired result on components that do not have proper mortise • Each system has its unique connection and complete engagement of implant abutment interface is critical for function of screw Prosthetic platform concept • The Regular Platform (RP) has been the design used with Branemark implant system since its origin. • The Narrow Platform (NP) has been designed for situation where there is limited inter-dental space or a narrow alveolar crest. • The Wide Platform (WP) is used in difficulty or complex circumstances where additional loading can be expected, or whenever a wider diameter implant/abutment interface is considered preferable. Screw The osseo integrated implant and the prosthetic abutment are joined by a screw and have, therefore, been named a screw joint. Design of screw for every brand is different From a mechanical point of view, to counteract screw loosening, “screw preload “ is necessary To maintain this preload tightening to recommended torque by each company is critical Screw • Screw Head • Material • Thread design Screw Screw driver Different screws have different screw driver base on the head of screw Screw Screw Driver Screw Head Screw The star shape of the screwdriver tip connects to the top of the healing components and abutment screw heads by friction fit, and offers good retention for safe pick-up and handling. Torque control device • Screw loosening is the#1 reason for prosthetic failure • To avoid screw loosening proper torque procedure is critical • Torque provide preload which is clamping force between screw and implant • Applying Torque more than what has been recommended by manufacture can fracture the screw • Applying Torque less than what has been recommended by manufacture results screw loosening 34 Bone-level vs Noble-Replace Macro Design : Taper Connection Internal Cross-fit Internal tri-channel Connection Interface Flat to flat interface Conical Interface Prosthetic platforms 1-Small connection (2.9mm) 2-Narrow connection(3.3mm) 3-Regular connection(4.1mm&4.8mm) 1-Narrow platform(3.5mm) 2-Regularplatform(4.3mm) 3-Wide platform(5.0mm) 4-6.0 platform(6.0mm) Bone-Level Noble-Replace Prosthetic platforms color coded 3 Prosthetic platforms SC NC RC 4 Prosthetic platforms Healing Abutment Noble –Replace Healing abutment Bone- Level Healing abutment Healing abutment Noble –Replace Healing abutment Bone- Level Healing abutment Color coded Prosthetic components Screw driver SCS Screw DriverStraumann Unigripe Screw DriverNoble Torque wrench Impression Tooth vs Implant Impression Tooth vs Implant Information that needed for Abutment selection and should be captured during impression : • Connection implant- restorative • Prosthetic platform • Emergence profile of healing/interim abutment • Orientation of implant(s) • Interocclusal distance • Depth of the peri-implant soft tissues. Impression Coping Analog (implant replica) Prosthetic Platform and Connection type needed to choose abutment Every abutment is compatible with a specific connection type and platform size Depth of the peri-implant soft tissues: Tissue height and emergence profile • The size of the abutment is determined by the best emergence profile possible. ■ The margins of the crown will be placed at gingiva level or just below gingiva level. Angulation of implant define design of prosthetic crown and the abutment that Needed for that design Implant angulation is too labially. This design compromised esthetic. Screw-retained Is a wrong design for this patient Implant angulation is palataly (under cingulum) . Screw-retained Is a correct design for this patient Interocclusal Distance define design of prosthetic crown and abutment for that • Length of abutment would be chosen base on interocclusal distance • For cement retained crown interocclusal space should be more than 7 mm if space is less than this only option is screw retained. • Impressions have the goals of capturing alveolar ridge and mucosal contours as well as position and angulation of implants. • Commonly used impression materials are polyvinylsiloxane and polyether ; Impression coping& Analog is used for capturing 3D position of implant and transferring it to final cast • intra-oral digital impression technologies are evolving options. Position of Implant determine Which abutment Which design Impression Coping Analog (implant replica) Open Tray vs Close Tray • An open tray technique requires use of impression copings that are attached to implants via a retaining screw and which must be accessible through the tray opening for loosening for impression retrieval. In this scenario, the impression copings remain embedded in the impression. Implant analogs are fastened to the copings and then the definitive cast is poured. • A closed tray technique can be used with tapered impression copings which are fastened directly to implants. In this scenario, the copings stay attached to the implants during impression retrieval and are placed back into the impression with implant analogs prior to pouring of the definitive cast Impression copings for Bone-level Open Tray b-after screwing impression coping x-ray should be taken to check the correct seating of impression coping a-Impression copings that are attached to implants by a retaining c-Impression coping must be accessible through the tray opening for loosening for impression retrieval Open Tray a-Unscrewing Impression coping to take out tray from the mouth b-The impression coping remains embedded in the impression. Open Tray Implant analogs are fastened to the copings and then the definitive cast is poured Closed tray impression Concept of snap-on impression cap Components: Cap (Polymer), Post (metal), Screw (Metal) the purpose of the cap is to provide a solid seat when placing the impression coping back into the impression. Benefits § Color-coded components correspond to prosthetic connection § No additional preparation of tray § High precision impression § Clear-cut tactile response for accurate positioning 61 Education Closed Tray The closed tray impression copings stay attached to the implants during impression retrieval , and are placed back into the impression with implant analogs closed tray Reading Impression for inserting back “impression coping + Analog “ is critical Digital Impression Intraoral scanners (IOS) IOS is a medical device composed of a handheld camera (hardware), a computer, and a software. The goal of IOS is to record with precision the three-dimensional geometry of an object in mouth. Intraoral scanners are capturing direct optical impressions in dentistry The most widely used digital format is the open STL (Standard Tessellation Language) Digital Impression Scan Body Implant position and orientation is accurately captured by the use of ’scan body . A scan body is a precise, autoclavable and reusable component which reliably engages with and attaches to the implant connection. Scan body is engaged to implant and intraoral scanner ,scan scan-body and and capture direct optical impression Digital Impression Scan Body Noble- Replace Bone-level Digital Impression Conventional Impression coping and PVS impression material Digital Scan Body and Scanner(STL file) ITI Resources Taking shade Impression transfers : alveolar ridge and mucosal contours as well as position and angulation of implants. For mounting the casts provider should follow all of the steps of traditional Prosthodontic treatments Information from Pre prosthetic evaluation: Information from Impression: Lip lines Maxillomandibular arch relationship Existing occlusion Crown height space Temporomandibular joint status Extraction of hopeless or poor-prognosis existing teeth Existing prostheses Arch form (ovoid, tapering, square) Natural tooth adjacent to implant site Soft tissue evaluation of edentulous sites …… Alveolar ridge and mucosal contours Position and angulation of implants. Is determinant factor to choose the appropriate abutment for fabricating final planned Prosthesis Standard abutment can be used: a-Minimum interarch space(CHS) should be 7 mm b-Distance between gingival margin and implant platform should be 2mm or less c-Implant angulation and position should be consistent with long axis of the tooth and centered Centered a b c Custom abutment should be used a-Distance between gingival margin and implant platform is more than 5mm b-Angulation implant is excessive c- Patient’s restoration needs very specific emergence profile d-For all screw-retained prosthesis E-Excessive interarch space more or limited interarch space(7 mm or less) f-In complicated treatment which discrepancy correction with standard abutment is not possible Excessive angulation a b f Prefabricated abutment (brand name:synocta) Prefabricated abutments with 3 unite cement-retained implant supported crown 75 Gold abutment Screw-retained Crown A custom designed metal alloy framework is casted from a wax pattern(cast able gold abutment). Porcelain is custom baked to the framework to provide excellent esthetics and hygiene access. CAD / CAM abutment Locator Denture cap Male processing Nylon Locator Abutment Tissue Depth# Abutment Height LOCATOR implant abutments should be ordered to the exact height of the gingival measurement Locator Driver universal Attachment is embedded inside denture Locator is screwed on implant (inside the mouth) Delivery Abutment is torqued Abutment seating Correct positioning of the abutment is essential for the prosthetic outcome and long-lasting function. • Position the abutment into the implant head and make sure the connection extension engages properly. • Make sure the abutment feels secure in place horizontally and vertically. • Tighten the screw, but not to full torque. • Take a radiograph to verify proper and full abutment seating: No apparent bone interference No gap in conical interface • Tighten the abutment screw to final torque. Tightening torque for Straumann abutments is 35 Ncm. Cementing implant supported cement retained crown • cement crown following all the criteria for conventional crown cementation Crown cemented on abutment Mounting of torque control device 85 Handling of torque control device Crown Delivery Cement Retained crown insertion: 1-Insert the abutment and torque the screw(35N) 2-Cement the crown on the abutment(Following Protocol of manufacture for cementation) Screw Retained crown insertion: Insert the crown and torque the screw(35N) OverDenture Delivery 88 Maintenance for Implant-supported Single Crown One-week follow-up after delivery & Recall Visit for Implant-supported Single Crown (every 3-6 month) • Obtain feedback from the patient about the implant site, comfort and function • Check -Oral hygiene compliance and presence of plaque. Clinical appearance of the peri-implant soft tissues: Take note of any swelling, bleeding or signs of infection such as suppuration or sinus. -Monitor if there is a collar of at least 2 mm of keratinized tissue around the implant. -Probe gently: there should be no bleeding on probing. -Stability of the crown: Check for any signs of de-cementation or unwanted movement of the crown. -Patient’s occlusion: Double check that the patient is still in proper occlusion both by verbal verification as well as well as intra-orally with occlusal marking paper. The occlusal status of the implant-supported crown must be evaluated on a routine basis. • Reinforce oral hygiene instructions and motivate the patient to take care of his or her new implant restoration. Maintenance for Implant-retained overdenture One-week follow-up after delivery & Recall Visit for Implant-supported Single Crown (every 3-6 month) • Obtain feedback from the patient about the implant site, comfort and function • Check Implant sites: Oral hygiene compliance and presence of plaque. Clinical appearance of the peri-implant soft tissues Check that there is a collar of at least 2 mm of keratinized tissue around the implants. Probing gently: there should be no bleeding on probing Soft tissue: Check for traumatized gingiva, particularly any area where the denture base may be causing excessive pressure. If so, reduce and subsequently smooth the relevant area on the denture Locator: Stability of Locator Abutments: Verify any signs of wear or mobility on the Locator abutments. Denture: Check the denture for Stability, retention and occlusion. Replace attachments as needed for better stability and retention. • Reinforce oral hygiene instructions and motivate the patient to take care of his or her new implant restoration. Thank you [email protected]