Prosthetic in implant.pptx

Prosthetic Options In Implant Dentistry Contents  CLASSIFICATION OF PROSTHEIS MOVEMENT Removable implant supported prosthesis 1. PM0 Fixed restorations in completely or partially edentuous patients 2. PM2 3. PM3  Partially edentulous prosthesis design 4. PM4  Misch’s prosthetic options in implant...

Prosthetic Options In Implant Dentistry Contents  CLASSIFICATION OF PROSTHEIS MOVEMENT Removable implant supported prosthesis 1. PM0 Fixed restorations in completely or partially edentuous patients 2. PM2 3. PM3  Partially edentulous prosthesis design 4. PM4  Misch’s prosthetic options in implant dentistry 5. PM6  OVERDENTURE OPTIONS  Introduction  Completely edentulous prosthesis design   1. FP1  CONCLUSION 2. FP2  RELATED ARTICLES 3. FP3  REFERENCES 4. RP4 5. RP5 Introduction Implant dentistr y Diagnosis of the patient’s condition Traditional dentistry Completely edentulous patients Limited optionsCD PATIENT Partial edentulism More options exits Many treatment options PROBLE M Treatment plan of choice Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.193 provide a range of abutment locations in either completely or partially edentulous patients there are limitations because the dentist cannot add abutments Restoration design is directly related to the existing oral condition. Implant dentistry Maximu m options BONE AUGMENTATION ADDS MORE OPTIONS Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.193 Patients are missing teeth, not implants!  BLUEPRINTS ideal goals of implant dentistry are to replace a patient’s missing teeth to NORMAL CONTOUR COMFORT FUNCTIO N SPEECH ESTHETIC S Blueprints indicate the finest details for buildings and are fabricated before the actual construction begins HEALTH  regardless of the previous atrophy, disease, or injury of the stomatognathic system  It is the final restoration, not the implants, that accomplishes these goals The end result should be clearly identified before the project begins and even before foundation requirements are established. historically Predetermined implant Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.193 bone available for implant insertion dictated the number and locations of dental implants The prosthesis was determined Reintroduced with computed tomography technology directed toward finding existing bone locations for implant insertion. To satisfy predictably a patient’s needs and desires, the prosthesis should first be designed. FIXED RESTORATIONS IN COMPLETELY OR PARTIALLY EDENTUOUS PATIENTS INDICATIONS patient has abundant bone and implants have already been placed, the lack of crown height space edentulous patients often believe the implant teeth are better than their experience with compromised natural teeth. fewer complications than overdentures Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.194 Crown height space  Key vertical parameter in treatment planning for the implant restorations. distance from the occlusal plane to the crest of the alveolar ridge in the posterior region distance from the incisal edge of the arch in question in the anterior region BARIUM SULFATE RADIO OPAQUE TEMPLATE visualize the final restoration at the onset with a fixedimplant restoration available bone evaluated to assess whether it is possible to place the implants to support the intended prosthesis individual areas of ideal or key abutment support are determined implant size and design selected to match force and area conditions The patient’s force factors and bone density in the region of implant support are evaluated The additional implants to support the expected forces on the prosthesis designed inadequate bone or implant abutment situations, the existing oral conditions must be improved The mind of the patient must be modified to accept a different prosthesis type and its limitations. PARTIALLY EDENTULOUS PROSTHESIS DESIGN  The fewer natural teeth missing, the better the indication for a fixed partial denture.  Fixed partial denture is completely implant supported rather than joining implants to teeth leads to the use of more implants in the treatment plan.  Cost disadvantage BUT significant intraoral health benefits.  added implants in the edentulous site results in fewer pontics, more retentive units in the restoration, and less stress to the supporting bone.  complications are reduced, and implant and prosthesis longevity are increased Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.195 Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.194 COMPLETELY EDENTULOUS predictable PROSTHESIS DESIGN Cost effective Patients anatomical needs Personal desires Most do not express serious concerns whether the restoration is fixed or removable as long as specific problems are addressed cost were the primary factor in establishing a treatment plan Some patients have a strong psychological need to have a fixed prosthesis (FP) as similar to natural teeth as possible. Axiom of implant treatment Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.194 REMOVABLE IMPANT SUPPORTED PROSTHESES implants are inserted into the anterior regions of the jaws (improved retention and stability ) soft tissues are also used to support the prosthesis chance of food entrapment Attachments need replacement acrylic denture teeth wear faster than porcelain to metal The anterior mandible has the greatest bone height in any region of the jaws. The incisal edge of a tooth is usually more facial, hence the implant often engages the lingual plate of bone. (more available bone in height than the posterior regions) Posterior regions of the jaws also resorb four times or faster than anterior regions Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.319 COMMON OPTION maxillary denture and a mandibular overdenture with two implants. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.194 When available bone dimension is lost more difficulty with retention and stability of the restoration in either arch Patients should be made aware of future compromises in bone loss and its associated problems with minimal treatment options Prosthetic options  In 1989, Misch  used to communicate the appearance of the final prosthesis to all of the implant team members, including the laboratory and patient. replace partial (one tooth or several) or total dentitions and may be cemented or screw retained depend on the amount of implant support, retention, and stability, not the appearance of the prosthesis inability of the patient to remove the prosthesis These options depend on the amount of hard and soft tissue structures replaced and the aspects of the prosthesis in the esthetic zone. Fixed prosthesis FP 1  to replace only the anatomical crowns of the missing natural teeth.  minimal loss of hard and soft tissues  The volume and position of the residual bone must permit ideal placement of the implant in a location similar to the root of a natural tooth  Final restoration appears very similar in size and contour  most traditional FPs used to restore or replace natural crowns of teeth. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.195  most often desired in the maxillary anterior region (esthetic zone during smiling ) Cervical diameter Natural teeth 6.5-10.5 mm Oval to triangular in cross section Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.196 Implant abutment 4-5 mm Round in cross secton Thin labial bone lying over the facial aspect of a maxillary anterior root remodels after tooth loss and the crest width shifts to the palate, decreasing 40% within the first 2 years. OCCLUSAL TABLE OF CROWN  modified in unesthetic regions to conform to the implant size and position and to direct vertical forces to the implant body  Eg. posterior mandibular implant-supported prostheses have narrower occlusal tables at the expense of the buccal contour because the implant is smaller in diameter and placed in the central fossa region of the tooth.  Maxillary posterior teeth often have reduced occlusal tables from the palatal aspect because the buccal cusp is often within the esthetic zone Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.197 BONE AUGMENTATIO N The width or height of the crestal bone is frequently lacking after the loss of multiple adjacent natural teeth  SOFT TISSUE AUGMENTATIO N no interdental papillae in edentulous ridges required to improve the interproximal gingival contour difficult to achieve when more than two adjacent teeth are missing. open “black” triangular spaces (where papillae should usually be present) when the patient smiles. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.197 RESTORATIVE MATERIAL Nobl e meta l Base meta l in case of a nonpassiv e fit at the metal tryin Can easily be separated and soldered in contact with implants corrode less than nonprecious alloys.  Substructure Any history of exudate around a subgingival margin will dramatically increase the corrosion effect between the implant and the base metal. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.197 material of choice - porcelain to noble-metal alloy improve the accuracy of the casting because nonprecious metals shrink more during the casting process A single tooth FP-1 crown may use aluminum oxide cores and porcelain crowns or ceramic abutments and porcelain crowns. risk of fracture may increase because impact forces are greater on implants than natural teeth FP2 An FP-2 fixed prosthesis appears to restore the anatomical crown and a portion of the root of the natural tooth. Restoration s are similar to teeth exhibiting periodontal bone loss and gingival recession  Volume and topography of the available bone are more apical compared with the ideal bone position of a natural root (1–2 mm below the cement–enamel junction) Incisal edge of the restoration is in the correct position gingival third of the crown is overextended, usually apical and lingual to the position of the original tooth Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.198 Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.198   Esthetic zone of a patient is established during smiling in the maxillary arch. The number of teeth displayed in a smile is variable. Only 4% of patients display almost all the maxillary teeth during a smile Almost 50% of patients display the teeth up to a first premolar. Tjan AH, Miller GD, The JG: Some esthetic factors in a smile, J Prosthet Dent 51:24-28, 1984.) If the teeth do not show during smiling or speech, an FP-2 restoration is not a compromise.  The low lip position is evaluated during sibilant sounds of speech (e.g., Mississippi).  It is not unusual for patients to show less lower anterior teeth during smiling, especially in younger patients.  Older patients are most likely to show the anterior teeth and gingiva during speech, with men showing more than women Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.199 If the high lip line during smiling or the low lip line during speech does not display the cervical regions; longer teeth are usually of no esthetic consequence  As the patient becomes older, the maxillary esthetic zone is altered.  Whereas only 10% of younger patients do not show any soft tissue during smiling  30% of 60-year-old adults and 50% of 80-year-old adults do not display gingival regions during smiling Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.199  The low lip position of the mandibular lip during speech is not affected as much as the maxillary lip during the high smile line.  Rarely do younger or middleage patients show the lower gingival during speech.  Only 10% of older patients show the mandibular soft tissue during speech.  Hence, FP-2 restorations in the mandible are common and usually of no compromise BONE WIDTH IMPLANT POSITION IN FP 2 ANGULATION HYGIENIC CONSIDERATION S IN FP1ESTHETIC DEMANDS Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.199 implant may even be placed in an embrasure between two teeth.  If this occurs, the incisal two thirds of the two crowns should be ideal in width,as though the implants were not present.  Only the cervical region is compromised.  It should be placed in the correct facial lingual position to ensure that contour, hygiene, and direction of forces are not RESTORATIVE MATERIAL OF CHOICE – PRECIOUS compromised METAL TO PORCELAIN Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.199 MESIO DISTAL POSITIONING OF IMPLANT – NOT SPECIFIC The amount and contour of the metal work is different than for an FP-1 restoration Amount of additional volume of tooth replacement increases the risk of unsupported porcelain in the final prosthesis, when the metal is undercontoured. FP3  As with the FP-2 prosthesis, the original available bone height has decreased by natural resorption or osteoplasty at the time of implant placement.  To place the incisal edge of the teeth in proper position for esthetics, function, lip support, and speech, the excessive vertical dimension to be restored requires teeth that are unnatural in length.  Patient may have a normal to high maxillary lip line during smiling or a low mandibular lip line during speech. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200 Pink-colored restorative materials to replace a portion of the soft tissue, especially the interdental papillae  The ideal high smile line occurs in almost 70% of the population and the maxillary lip displays the interdental papilla of the maxillary anterior teeth but not the soft tissue above the midcervical regions  Approximately 7% of men and 14% of women have a high smile or “gummy” smile and display the interdental papillae and at least some of the gingival tissues above the free gingival margin of the teeth.  Patients in both of these categories of high lip line should have the soft tissue replaced by either the prostheses or the Misch CE. Dental Implant Prosthetics-Epatient’s soft tissue Book. Elsevier Health Sciences; 2004 Sep 20.200,201 Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,202  The patient may also have greater esthetic demands even when the teeth are out of the esthetic smile and speech zones.  Patients complain that the display of longer teeth appears unnatural even though they must lift or move their lips in unnatural positions to see the covered regions of the teeth. The addition of gingival-tone acrylic or porcelain for a more natural FP appearance is often indicated with multiple implant abutments because bone loss is common with these conditions, and the soft tissue drape is more difficult to appear ideal Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,203 Misch CE. Dental Implant Prosthetics-EBook. Elsevier Health Sciences; 2004 Sep 20.200,203  There are basically two approaches for an FP-3 prosthesis: (1) a hybrid restoration of denture teeth and acrylic with a metal substructure (2) a porcelain–metal restoration  An FP-3 porcelain-to-metal restoration is more difficult to fabricate for the laboratory technician than an FP-2 prosthesis.  The pink porcelain is harder to make appear as soft tissue and usually requires more baking cycles.  This increases the risk of porosity or porcelain fracture. primary factor that determines the restoration material is the amount of crown height space EXCESSIVE CROWN HEIGHT SPACE porcelain– metal restoration will have a large amount of metal in the substructure increase in porcelain fracture PORCELAIN THICKNESS NOT > 2mm Misch CE. Dental Implant Prosthetics-EBook. Elsevier Health Sciences; 2004 Sep 20.200,203 acts as a heat sink and complicates the application of porcelain during the fabrication of the prosthesis. as the metal cools after casting, the thinner regions of metal cool first and create porosities in the structure. when the casting is reinserted into the oven to bake the porcelain, the heat is maintained within the casting at different rates; thus, the porcelain cool-down rate is variable, which increases the risk of porcelain fracture fracture of the framework after loading weigh t and cost Hybrid restoration  An alternative to the traditional porcelain– metal FP  A smaller metal framework, with denture teeth and acrylic to join these elements together.  Less expensive  highly esthetic because of the premade denture teeth and acrylic pink soft tissue replacements.  Intermediary acrylic between the denture teeth and framework may reduce the impact force of dynamic occlusal loads.  easier to repair in the case of porcelain fracture because the denture tooth may be replaced with less risk than adding porcelain to a traditional porcelain–metal restoration Fatigue of acrylic is greater than the traditional prosthesis; therefore, repair of the restoration is more commonly needed. INDICATIONS FOR FP2/FP3  Implants placed too facial or lingual or in embrasures  when vertical bone has been lost  greater crown heights allow the correction of incisal edge positions  extremely high smile lip line often extended or juxtaposed to the maxillary soft tissue so that speech is not impaired In the maxillary arch, wide open embrasures between the implants may cause food impaction or speech problems. Greater moment of force is placed on the implant cervical regions, especially during lateral forces (e.g., mandibular excursions or with cantilevered restorations). Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,203 There are two types of RPs based on support, retention, and stability of the restoration  Patients are able to remove the restoration but not the implant supported superstructure attached to the abutments. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep VERSUS NORMAL CD  The most common removable implant prostheses are overdentures for completely edentulous patients. Misch CE. Dental Implant Prosthetics-EBook. Elsevier Health Sciences; 2004 Sep 20.575 RP 4  RP completely supported by the implants, teeth, or both.  The restoration is rigid when inserted: overdenture attachments usually connect the RP to a low-profile tissue bar or superstructure that splints the implant abutments.  Usually five to seven implants in the mandible and six to eight implants in the maxilla are required to fabricate completely implant supported RP-4 prostheses in patients with favorable dental criteria Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,204 IMPLANT PLACEMENT CRITERIA FOR RP4 PROSTHESIS  Different than that for an FP  Denture teeth and acrylic require more prosthetic space for the removable restoration.  A superstructure and overdenture attachments must often be added to the implant abutments.  This requires a more lingual and apical implant placement compared with the implant position for an FP. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,204 The implants in an RP-4 prosthesis (and an FP-2 or FP-3 restoration) should be placed in the mesiodistal position for the best biomechanical and hygienic situation  Position of an attachment on the superstructure or prosthesis may also affect the amount of spacing between the implants.  For example, a Hader clip requires the mesiodistal implant spacing to be greater than 6 mm from edge to edge and as a consequence reduces the number of implants that may be placed between the mental foramina. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,204  The RP-4 prosthesis may have the same appearance as an FP-1, FP-2, or FP-3 restoration.  A porcelain-to-metal prosthesis with attachments in selected abutment crowns can be fabricated for patients with the cosmetic desire of an FP.  The overdenture attachments permit improved oral hygiene or allow the patient to sleep without the excess forces of nocturnal bruxism on the prosthesis.  The prosthesis is very similar to traditional overdentures supported by natural teeth Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.200,204,332 RP 5  RP-5 is an RP combining implant and soft tissue support.  amount of implant support is variable.  A completely edentulous mandibular overdenture may have (1) two of three anterior implants independent of each other primarily for retention (2) splinted implants in the canine regions to enhance retention and stability (3) three splinted implants in the premolar and central incisor areas to provide improved retention and lateral stability (4) four or five implants splinted with a cantilevered bar to improve retention, stability, and support which reduces soft tissue abrasions and limits the amount of soft tissue coverage needed for prosthesis support. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.204 CLASSIFICATION OF PROSTHESIS MOVEMENT (MISCH 1985)    Evaluates the directions of movement of the implantsupported prosthesis PM-0 An overdenture is by PM-2 definition removable, but in function or parafunction, the PM-3 prosthesis may not move. The dentist determines the amount of PM the patient desires or the anatomy may tolerate PM-4 PM-6 does not have movement during function with hinge motion Apical and hinge motion Movement in 4 directions Movement in all directions Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.580 PM 0  If the prosthesis is rigid when in place but can be removed, the PM is labeled PM-0 regardless of the attachments used.  O-rings may provide motion in six different directions.  But if four O-rings are placed along a complete arch bar and the prosthesis rests on the bar, the situation may result in a PM-0 restoration PM 2   hingelike PM permits movement in two planes (PM-2) and most often uses a hingelike attachment Dolder bar and clip without a spacer or Hader bar and clip are the most commonly used hingelike attachments. DOLDE R BAR HADER BAR EGG shaped in cross section A clip attachment may rotate directly on the Dolder bar Flexes to a power of 3 ROUND in cross section More flexible Flex to the power of four contribute to unretained abutments or bar fracture apron is added to the tissue side of the Hader bar to limit metal flexure Hader bar Transforms the prosthesis and bar into a more rigid assembly A cross-section of the Hader bar and clip system reveals that the apron, by which the system gains strength compared with a round bar design may be used for a PM-2 when posterior ridge shapes are favorable and soft tissue is firm enough to limit prosthesis rotation. PM 3 DOLDER BAR 6 SPACER WITH AND CLIP FACIAL,LINGUAL AND GINGIVAL PM 4 MAGNETS MESIAL,DISTAL FACIAL AND LINGUAL PM O RING ATTACHMENT OCCLUSAL,GINGIVAL,MESIAL, DISTAL,FACIAL,BUCCAL AND LINGUAL Dolder bar MANDIBULAR OVERDENTURE TREATMENT OPTIONS Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.579 Overdenture option 1 O-ring or Locator design. stability and support of the prosthesis are gained primarily from the anatomy of the mandible and prosthesis design, which is similar to a complete denture. Disadvantages Poor implant support and stability Decrease in occlusal force Increase in prosthetic maintenance appointments Posterior bone resorption two-mandibular implant overdenture should oppose a complete denture. Otherwise, instability and sore spots are common related to the implant overdenture. A, A panoramic radiograph of two independent implants in a division D mandible. B, One implant failed, and the mandible fractured through The support requirements of the posterior regions of the mandible the are reduced when opposing a complete denture  The ultimate goal in the treatment plan is to convert OD-1 patients to a RP-4 or fixed prosthesis with more implant support and stability before the loss of the posterior bone in the mandible occurs behind the foraminae.  As soon as the patient can afford two more implants, the implants should be placed in the A and E position, and all four ABDE implants should be connected with a bar that may be cantilevered to the posterior and help reduce the posterior bone loss. Overdenture option 2 Attachments are placed parallel to each other and at the some occlusal height. O-ring attachments are also positioned equal distance off the midline.  Reduced loading forces are exerted on two anterior implants when splinted with a bar compared with individual implants.  The bar is designed to position the attachments an equal distance off the midline parallel to each other at the same occlusal height and in a similar angulation to provide added retention The ideal distance between the implants is in the 14- to 16-mm range or B and D positions. Implants placed closer than the B, D position will result in reduced prosthesis stability during function whether they are connected or independent units. The connecting bar should not be cantilevered to the distal from the two implants Implants in the A, E position were splinted together with a bar. The prosthesis screw became loose on the A implant, which resulted in a long cantilever on the E implant, which then failed. Overdenture option 3  Three root form implants are placed in the A, C, and E positions  A superstructure bar connects the implants but with no distal cantilever  The A-C-E implant and bar position is much more stable than the B-D position for the prosthesis. In the future convert it in to RP 4 OR any FP Overdenture option 4  The cantilevered superstructure is a feature of the four or more implant treatment options in a completely edentulous arch for three reasons: 1. increase in implant support compared with OD-1 to OD-3. 2. biomechanical position of the splinted implants is improved in an ovoid or tapering arch form compared with OD-1 or OD-2. 3. additional retention provided by the fourth implant for the superstructure bar, which limits the risk of prosthetic screw loosening and other related complications of cantilevered restorations. A-P spread between implants in the A, E and D, B positions is greater and therefore permits a longer distal cantilever. This A-P spread is usually 8 to 10 mm in these arch forms and therefore often permits a cantilever up to 10 mm from the A and E positions Advantages  Greater occlusal load support, lateral prosthesis stability, and improved retention.  The prosthesis loads the soft tissue over the buccal shelf and the first and second molars and retromolar pad regions.  amount of occlusal force on the implant system is reduced (compared with a fixed restriction or RP-4 prosthesis) because the bar does not extend to the molar position, where the forces are greater. Disadvantages  The OD-4 treatment option is the lowest treatment rendered when the patient has maxillary teeth.  The greater vertical and horizontal forces to the mandibular IOD require anterior disclusion in excursions to decrease the bite force.  As such, more anterior implants are required under these conditions The next treatment plan option for the patient with a moderate financial budget is to add an additional implant in the future in one of the first molar positions (preferred) or the C position. Both of these options increase the A-P spread to fabricate a RP-4 prosthesis with an enhanced implant system support. The goal is to convert all patients eventually to a RP-4 or fixed restoration, to prevent posterior bone loss and its associated disadvantages (including esthetics of the posterior facial regions). Overdenture option 5  The amount of the distal bar cantilever is related (in part) to the A-P distance. Arch shape affects the anteroposterior (A-P) distance. A, The square arch form is less than 5 mm. B, The ovoid arch form often has an A-P distance of 5 to 8 mm. C, A tapered arch form has the greatest A-P distance, larger than 8 mm. The mandibular arch form may be square, tapering, or ovoid. Square arch forms limit the A-P spread between implants and may not be able to counter the effect of a distal cantilever. Therefore, rarely are distal cantilevers designed for square arch forms No prosthetic load on posteriors Posterior implants Avoid load on posterior residual ridge Resorption process is delayed Cantilevered bar and overdenture Indications maxillary arch has natural teeth (especially in a young patient or male patient) INCREASE ANTEROPOSTERIO R SPREAD  completely implant-supported prostheses often increase the amount of posterior bone height even when no posterior implants are inserted. patient desires a RP-4 or fixed restoration CONCLUSIO N Prosthesis may be fixed or removable for completely edentulous patients, fixed restorations are planned for most partially edentulous patients Gives a desired prosthodontics result Additional foundation units Patient factors Psychological and anatomical needs and desires of the patient Design prosthesis Benefits of implant dentsitry Misch CE. Dental Implant Prosthetics-EBook. Elsevier Health Sciences; 2004 Sep That satisfies these goals and eliminates the existing problems realized only when the prosthesis is first discussed and determined An organized treatment approach based on the prosthesis permits predictable therapy results. Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.205 Amount of support required for an implant prosthesis FP3/ FP2 FP1 Prosthetic option first factor to determine overall implant treatment plan FP-1 prosthesis, when desired, may have a narrow implant inserted rather than an osteoplasty and a larger diameter implant RELATED ARTICLES “Combination Syndrome” in an Upper/ Lower Implant Overdenture Patient: A Clinical Report  An upper/lower overdenture case, which presented with clinical entities commonly associated with the combination syndrome, is described.  clinical presentations reminding of combination syndrome features were described in patients wearing upper complete dentures opposing lower implant retained/ supported overdentures  main observation was related to increased bone loss in the anterior maxilla 2 O Ring attachments in sites #5 and #12, 1 Locator attachment #2, and 1 extracoronal resilient attachment in site #15. The attachments were worn out 1 Disproportioned bone loss can occur in various extents in patients treated with prostheses having mixed support (implants/ tissue). Regular recalls are paramount, to preserve the health of supporting tissues and improve the longevity of restorations. Rehabilitation of Maxillofacialtrauma Patient with Dental Implants: A Case Report Patient-reported outcome measures of edentulous patients restored with implantsupported removable and fixed prostheses: A  Overall, the OHRQoL and satisfaction of edentulous patients were systematic review significantly improved after wearing implant-supported prosthesis compared to their OHRQoL and satisfaction ratings before treatment.  These improvements can be found in almost all domains, including comfort, function, aesthetics, speech, self-esteem  When comparing between IOD and IFCD, however, the reported outcomes were inconsistent.  The majority of the reviewed studies reported that IFCD performed better in the aspects of overall satisfaction and OHRQoL  IOD being easier to maintain oral hygiene  IFCD needs to have a design that allows access for efficient oral hygiene and that patients, who receive such reconstructions, must be adequately trained for their particular prosthesis How many implants are necessary to stabilise an implant-supported maxillary overdenture? Guenin C, Martín-Cabezas R Evidence-Based Dentistry. 2020 Mar;21(1):28-9.  Twenty-eight studies were included in the systematic review.  The survival rate of implants appeared to be higher when at least four implants were placed to support the overdenture, compared to less than four implants.  Patient satisfaction were not influenced by the number of implants.  The metanalysis could only be performed to compare the implant survival rate of a four splinted implants group and more than 4 splinted implants group, without significant differences between both groups References  Misch CE. Dental Implant Prosthetics-E-Book. Elsevier Health Sciences; 2004 Sep 20.  Oda K, Kanazawa M, Takeshita S, Minakuchi S. Influence of implant number on the movement of mandibular implant overdentures. The Journal of prosthetic dentistry. 2017 Mar 1;117(3):380-5.  Yao CJ, Cao C, Bornstein MM, Mattheos N. Patient‐reported outcome measures of edentulous patients restored with implant‐supported removable and fixed prostheses: A systematic review. Clinical oral implants research. 2018 Oct;29:24154.  Guenin C, Martín-Cabezas R. How many implants are necessary to stabilise an implant-supported maxillary overdenture?. Evidence-Based Dentistry. 2020 Mar;21(1):28-9.  Gandhi N, Gandhi S, Kurian N, Mehdiratta S. Rehabilitation of maxillofacialtrauma patient with dental implants: A case report. CHRISMED Journal of Health and Research. 2018 Jan 1;5(1):80.  Oh SH, Kim Y, Park JY, Jung YJ, Kim SK, Park SY. Comparison of fixed implant‐ supported prostheses, removable implant‐supported prostheses, and complete dentures: patient satisfaction and oral health‐related quality of life. Clinical oral implants research. 2016 Feb;27(2):e31-7. THANK YOU!