CGD Exam #5 PDF

Dr. Alborz Endo Lecture Steps in endo: ○ PA and bwx ○ CBCT - if indicated ○ Rubber dam isolation ○ Caries control/gingivectomy (prn) ○ Determine restorability and DO build-up ○ Remove roof of pulp w/ safe-ended carbide...

Dr. Alborz Endo Lecture Steps in endo: ○ PA and bwx ○ CBCT - if indicated ○ Rubber dam isolation ○ Caries control/gingivectomy (prn) ○ Determine restorability and DO build-up ○ Remove roof of pulp w/ safe-ended carbide ○ Locate canals ○ Shape, clean, obturate, prep, light occlusion ○ RX: 600mg ibuprofen q6h prn pain. ABX only if swollen (typically first 72 hours) Pulpal diagnosis ○ Normal ○ Reversible pulpitis - sharp response to cold that resolves immediately ○ Irreversible pulpitis - 2 types Symptomatic irreversible pulpitis - sharp response to codl that lingers beyond 3-5 seconds and changes to dull, throbbing ache Asymptomatic irreversible pulpitis - normal response to cold after a carious pulpal exposure ○ Necrotic - no response to cold ○ Previously treated ○ Previously initiated tx: pulpotomy or pulpectomy Periradicular diagnosis ○ Normal ○ Symptomatic periradicular periodontitis - tenderness to percussion Rx findings may or may note be present ○ Asymptomatic periradicular periodontitis - normal to percussion Rx present ○ Acute periradicular abscess - swelling is observed clinically, w/ or w/out drainage Rx normal ○ Chronic periradicular abscess - swelling is observed clinically, w/ or w/out drainage Rx POSITIVE TTX resistant ○ Tetrodotoxin - resistant Na channels ○ A form of Na channels resistant to L/A ○ Up-regulation during inflammation Hygienic rubber dam ○ Used as barrier during endo procedures ○ Latex and non-latex dam ○ Framed flexi-dam (non-latex) ○ Extended reach punch ○ Dental dam clamps (fiesta color-coded) 12A - lower right/upper left 13A - lower left/upper right 2A - PM (most molars) 9 - anterior ○ Wedjets (latex and non-latex) Why bwx? ○ Height of pulp chamber ○ Extent of caries  ○ Quality and margins of existing restoration ○ Attachment loss (perio status) Other random notes: Test culprit tooth last A-delta fibers = responsible for pain ○ Only fibers we can test for!** → CANNOT test for C fibers C-fibers = innervate central pulp Activated C-fibers = irreversible pulpitis Heat causes fluid to go into pulp, ice will cause fluid to come away from the pulp Endo diagnosis: pulpal and periapical Pulpotomy vs pulpectomy ○ A pulpotomy is a less invasive procedure that only involves removing the infected pulp from the pulp chamber. ○ A pulpectomy, on the other hand, is more complex and involves removing all of the infected tissue from the pulp chamber, root canals, and the root of the affected tooth. While a pulpotomy is done on a live tooth, pulpectomies and root canals are both done on teeth that are no longer vital due to trauma or an infection in the nerve LISTEN TO YOUR PTS Cold test varies from pt to pt Buccal infiltration w/ articaine is better than lidocaine Intraossesos - gold standard for general anesthesia Block upstream before going to culprit tooth Crack tooth w/ >5-7mm probing = extraction Cracked teeth are on MESIAL and DISTAL marginal ridges Vertical root fracture are usually post-endodontics - will fracture BUCCAL and LINGUAL MIE - minimally invasive endo If you have a thin height in pulp chamber - FOR THE LOVE OF GOD DO NOT DO IT ○ You will perf, you will get chlamydia, you will die Alternative Removable Partial Denture Designs Interim partial dentures ○ AKA - temporary partials, immediate partials, “flippers” ○ Typically made from resin material - may be produced by sprinkling method (like ortho retainer), visible light-cured (VLC) method (triad, like custom tray) or by waxing, flasking, processing w/ auto-polymerizing or heat polymerizing resin (PMMA, like conventional dentures) Typically do NOT have cast metal base ○ Typically retained by circumfrential wrought-wire clasps, crozat-type clasps, interproximal spurs, wire loops ○ Partial codes - broken down by material and when they are delivered In fuse, we have lots of options (feel free to explore on your own) ○ ADA defines interim - restoration or prosthesis designed for use over a limited period of time Procedure that whose outcome is, by intent, subject to change arising from subsequent delivery of another procedure The “interim” period of time for a restoration, prosthesis or procedure, is determined by clinical and professional judgement of dentist ○ Most of, if you were to send impressions to lab & ask for interim partial, they will send back PMMA resin base w/ wrought wire clasps You can technically ask for any material (cast, flexible base, acrylic) at any stage (immediate, interim, definitive) Difference will be lab bill & pt bill - as well as reimbursement rates from insurance companies Interim vs immediate ○ Interim denotes temporary nature of restoration ○ Immediate refers to restorations immediately at time of extractions ○ Not always synonymous! Can fabricate interim restoration at any time but an interim restoration delivered at the time of extraction is immediate ○ Unlike complete dentures, rarely is immediate partial denture relined & converted into “definitive” prosthesis b/c, most often, temp partials are resin based w/ wrought wire clasps Redlining will result in better tissue adaptation, but will still have less retention and durability as compared to cast metal Interim partial dentures: applications ○ Purpose of these partials is to achieve tx outcomes w/ minimal time and expense to both ourselves and pt ○ b/c these are designed to be quick and cheap, they have compromised stability and support Important to note this to pt & for them to understand we are designing these prostheses w/ intention of replacing them ○ They may jeopardize integrity of adjacent teeth and health of supporting tissue if worn for extended periods w/out supportive care Interim partial dentures: goals ○ 6 treatment goals/reasons for fabricating interim partials: Appearance/aesthetics Most common reason to make these Some pts will note go w/out teeth for any period of time & will request a partial to repalace their teeth prior to definitive restoration Maintenance of space If you anticipate teeth will be missing for an extended period of time, may be prudent to fabricate a partial to prevent supra-eruption or drifiting of teeth ○ Especially important if you are anticipating placing implants in future & you may be waiting an extended period of time before restoration of implants  Also important to think about in younger pts - may need to wait until teeth/jaws have reached sufficient maturity to be prepared for definitive restorations Re-establishment of occlusal relationship Book cites that this can be done - particularly in cases where partial is tooth-borne, however this is more commonly completed w/ fixed pros ○ Major issue is that if the pt is uncomfy w/ the new occlusal relationship, they can just take the partial out In cases w/ a distal extension (tissue borne), establishment of new occlusal relation depeond on the quality of support and stability the partial/splint receives from the denture support ○ Both broad coverage and function basing of tissue-supported bases are desirable, along w/ some type of occlusal rest of the nearest abutments CANNOT be accomplished w/ flexible case partial Conditioning of teeth and residual ridges Tissues of residual ridge become more capable of supporting a distal extension RPD when they have been previously conditioned by wearing of restoration ○ Additionally, w/ abutment teeth, especially those that were previously out of occlusion - some intrusion of the tooth will occur after placement of a partial Placing an interim allows this process to occur prior to the definitive restoration Interim restoration during tx Provides fxn when chewing and speaking to pt in interim Conditioning pt for wearing prosthesis Gets pt used to partial or removable prosthesis in general ○ Pts can get conditioned to function of removable prosthesis/care/etc ○ Common applications for interim partial dentures: Immediate partial - to be delivered at time of extractions and worn while tissue heals, then definitive partial can be fabricated Interim partial while waiting for implant placement/fixed restorations Transitional partial dentures for pts when questionable to hopeless remaining teeth (can eas transition to complete dentures) Interim partial dentures: pros and cons ○ These refer to resin-based interim partials w/ wrought wire clasps - which is the most common “interim” partial ○ Pros: Cheaper than other partials & much cheaper than fixed/implants Easy to design/fabricate Minimal intraoral prep required prior to fabrication Usually turned around quickly by lab & can be made in house relatively easily Aesthetics are not excellent but are usually satisfactory (depends, often, on clasp location) ○ Cons: Function is relatively poor - wrought wire clasps bend more easily and have poor retention No durable - have no cast metal base to support them and do not flex, so easier for pt to break during function/dropping partial/etc Wrought write clasps are not aesthetic and will wear out over time ○ Bottom line: Tell pts these are more for taking pics than for eating These will give pt something to smile w/ but are not meant to be definitive restoration Interim partial dentures: clinical procedures ○ These are typically fabricated on UNPREPARED teeth - this means no rest seats, guide planes, etc This means that the partial will be almost exclusively tissue supported & thus less stable  Also means lab may need to block out infra-bulge regions on teeth or significant gingival undercuts to allow partial to seat → leading to looser fit We can get away w/ this through use of wrought wire clasps - which are more flexible and will pass over the height of contours of the teeth more easily w/ this greater flexibility comes reduced durability, clasps will wear out/break faster than cast clasps ○ Impressions - we will need upper, lower, bite Since this is an interim restorations, use of alginate and stock plastic trays is typically adequate In the event that you will not be pouring up your models to send to the lab, more stable materials like VPS ($$$) or alginate substitute ($) can be used ○ Design - can be completed on a design cast or on a lab script, if design will be fairly straightforward As these will not feature cast clasps/guide planes, they typically do not require surveying prior to design However, if pt has a particularly complex/deviated path of insertion, may still be best to survey the cast These will be retained w/ wrought wire clasps, which cna be placed on almost any teeth and bent to meet the undercut as needed These will typically be placed on: 1) teeth adjacent to the edentulous space and 2) the most posterior teeth in a quad ○ Modifications may need to be made due to aesthetics or functional reasons (x-bite/malocclusion, wire clasp may interfere w/ pt’s bite) Because these are supported almost exclusively by tissues, is often best to maximize tissue coverage w/ resin base This means either full palatal coverage or horseshoe design on upper arch & lingual plating w/ extension to retromolar pads on lower arch ○ Cast modifications - if interim partial to be delivered is also to be immediate partial, will want to make cast modifications prn - just as you would for immediate denture You will want to indicate any modifications you have made to the lab If mods will affect the stability of bite, you will want to mouth the casts prior to sending them off Similarly, you will wnat to mark a midline/commisure line as needed ○ Lab RX - “Please fabricate a resin base interim partial denture for ___ arch. Teeth __#__ have been removed from the cast. Midline and commissure line are marked on case and case is mounted. Please clasp tooth ___ w/ wrought wire clasps and extend denture base as drawn in Rx. Please use teeth shade ___ and acrylic shade ___. The denture is opposing ___, so please use ___ teeth. Thanks!” ○ Delivery - extract teeth as needed if delivering an immediate partial Try partial denture in, check for interference during seating, make sure appliance is seated fully (checks for gaps in intaglio, rocking when biting, lack of contact on natural teeth) Adjust high spots/overextension of acrylic as needed w/ straight handpiece and acrylic bur Can check intaglio and flange length w/ PIP Can adjust wrought wire clasps w/ pliers (2 or 3 prong) to either make more or less retentive Finally, can check occlusion and adjust high contact prn Typically, you want the partial to contribute to pt’s occlusion, but not be the sole source of occlusal contact ○ Adjustments - will typically need at least one adjustment or at least a recall to check for any irritating spots, adjust retention, etc Care - want to remove a night, remove partial after eating and clean good debris if possible Pts can use adhesive but want to remove it daily Can hard or soft reline these if needed - however, if significant tissue change has occurred, may be best to fabricate new (definitive) partial  Flexible base partials ○ What are they? These are made from a thermoplastic resin material, which is defined as a plastic which becomes pliable or moldable above a specific temp and returns to a solid state upon cooling Many types of these resins available, including: Thermoplastic acetal Thermoplastic polycarbonate Thermoplastic acrylic Thermoplastic nylon Thermoplastic polyolefin (polyethylene and polypropylene) Thermoplastic nylon is inherently flexible when cooled back to a solid state - so many of the flexible base partials on the market are of thermoplastic nylon base ○ Biggest name is the marker for some time has been Valplast - which is a thermoplastic nylon based partial w/ their one lab, injection system, etc ○ Oral Arts offers a nylon base (TCS Unbreakable) and polyolefin base (Duraflex) option for flexible partials ○ Thermoplastic nylon has high physical strength, heat resistance, chemical resistance, and can be easily modified to increase stiffness and wear resistance - often material of choice but other options are available w/ slightly different properties Flexible base partials: applications and goals ○ Flexible base partials have several applications and can be very successful in certain cases ○ Most often used as: More aesthetic and functional interim partial (as compared to resin based partials) prior to fabrication of definitive partial denture or prior to placement of implants/fixed pros Definitive partial for small, unilateral spans, or for smaller anterior spaces Definitive partial for pts w/ significant hard tissue undercuts, in which pt does not want to perform pre-prosthetic surgery ○ These are rarely indicated as definitve partial denture in cases where significant posterior edenutlous spans are present Reasoning behind this is based on inherent properties of thermoplastic resins Flexible base partials: pros and cons ○ Pros These are flexible! Pts often report that these are more comfy upon insertion & they can be inserted around/over (reasonable) undercuts Thermoplastic resin is translucent and makes for a very aesthetic restoration No metal clasps or rest seats further improve aestheics Does not typically require rest seats or guide planes due to flexibility Lighter weight than cast partials & is very difficult to break Cost is more than resin based but comparable or cheaper than cast metal b/c they are not tooth borne, they can put less force on remaining teeth that would otherwise have to bear the load of the partial ○ Cons These are flexible. In case of distal extensions, these partials are not as rigid or resilient as cast metal base partials This can result in discomfort from excessive flexing when dealing w/ long spans, especially distal extensions Thermoplastics, especially nylon, are less chromatically stable than PMMA These pick up stain more easily and will discolor more rapidly Challenging to adjust, as Valplast & other thermoplastics tend to melt during adjustment Specialized bur kits will help but are costly  As opposed to resin (PMMA) bases, denture teeth do NOT bond to thermoplastics, meaning they are retained w/ mechanical retention alone Thus they have minimum dimensions for fabrications to ensure enough base material to retain the teeth Flexible base partials: clinical procedures ○ Typically do not require prep of teeth prior to taking impressions b/c they are flexible, they will typically seat over significant undercuts and adapt well to tissues However, b/c they do not have rest seats, they will be fully tissue supported ○ Will follow same clinical procedures for resin based interim partials (essentially) Can take impressions w/ alginate (for interim partial) or VPS (better used for definitive restorations) and will need a bite registration ○ These can be placed immediately after extractions - so will need to make cast mods as need ○ Design principles are fairly similar - typically clasps will be placed on teeth adjacent to missing spaces and most posterior teeth in quad w/ max tissue coverage for max support ○ These will be clasps w/ thermoplastic clasp designs - which will often look different from cast clasps If you have specific clasp design in mind, best to draw on cast or lab rx ○ Exception to these design principles is the Nesbit or “spider” partial - which can be excellent for anterior single tooth spaces, as when waiting for implant integration In this case, partial will not have max tissue coverage or support - but can be more comfy to pt & is ideal when pt is alright w/ sacrificing function of partial ○ Delivery and adjustment are similar to resin based partial - the main difference is that adjustment of thermoplastic material is tricker than PMMA Additionally, clasps are typically resilient - so cannot be adjusted w/ pliers ○ Care should be taken during adjustment not to adjust too aggressively as as to not melt thermoplastic material ○ These will often be very comfy upon insertion but can wear sore spots during function due to flexibility - so adjustment appt after a few days if prudent Flexible base partials: the bottom line ○ Flexible base partials are a great alt to resin based interim partials They have specific applications, such as unilateral designs, Nesbit designs, or on pts w/ heavy undercuts Additionally, pts who have tried cast partials in the past and disliked their rigidity may favor flexible based partials ○ Downsides: often do not serve as viable alternative to cast metal partials for definitive partial denture restorations due to limited support and function and chromic stability ○ These downsides should be presented to pt at time of tx planning Given pt’s goals and tx considerations, you should advise and come to an agreed tx plan accordingly Combonation partials ○ Partials that feature a cast metal framework, complete w/ occlusal rests and cast clasps where desired, but w/ a thermoplastic resin base as opposed to a PMMA base, as w/ conventional cast metal partials ○ Flexible base clasps, which can be more comfy and aesthetic, can be placed as desired ○ These offer something of a “best of both worlds” (cue Hannah Montana song) option. However, it must be noted that some of the downsides of flexible base partials remain  Namely, their chromatic instability and their lack of clasp resiliency remain detractors to this design Also, these are the most expensive to order from the lab ○ With these partial designs, design process should be nearly identical to conventional cast metal partials - including rest seat preps, surveying, etc. Can also typically ask for a framework try-in w/ these partial denture designs to confirm fit before processing ○ Clarify tx options w/ your lab as needed Denture Maintenance: Relines and Rebases What are these? ○ Relines and rebases are attempts to extend functional life of a denture ○ Both biologic tissues of the mouth and materials used to fabricate dentures will change over life of denture (more rapidly in some cases than others) Relines and rebases are attempts to update prosthesis to reflect these changes ○ Alternative to these procedures → remake the denture Denture remakes are inevitable, but oftentimes, these procedures can extend the life of denture for the pt However, there are some cases where a reline or rebase will not help pt or when they are not necessary Identifying these cases will save you & pt time/money Reline ○ Procedure used to resurface tissue side of denture w/ new base material that provides accurate adaptation to changed denture-foundation area (adding more pink stuff to existing pink stuff) ○ Can be done w/ a variety of materials & can be performed either directly (chairside) or indirectly (w/ lab) Rebase ○ Lab process of replacing entire denture base material in an exisitng prosthesis (replacing all the pink stuff, keeping same teeth) ○ More complex and involved procedure & must be performed indirectly w/ a lab Diagnosis ○ Denture pts will call in or present to your chair reporting looseness, soreness, chewing inefficiency, pain during function, etc In case of immediate dentures, this will typically be soon after delivery of prosthesis In case of conventional denture, this should not occur as rapidly - often presenting at an annual/semi-annual recall appt ○ “Looseness” during function may be from: Occlusal or fit imbalance in prosthesis that was present at delivery Occlusal or fit imbalance that has developed as a result of changing tissue or wear of the prothesis over time ○ Key diagnostic factor is length of time since delivery w/ immediate denture, rapid tissue changes are anticipated so fit or occlusal discrepancies shortley after delivery are more likely to be due to tissue changes w/ conventional denture, espeiclaly w/ significant time post-ext (2+ years) rapid tissue changes are not anticipated Occlusal or fit discrepancies shortly after delivery are more likely to be due to an inherent tissue w/ the denture ○ It is often best to attempt to check stability of dentures independently if accuracy of occlusion is in question You can place each denture lightly on each respective arch and apply moderate pressure vertically and horizontally Well-adapted denture should only move 1-2mm and not exhibit rocking or excessive movement ○ Tissue adaptation can be checked w/ PIP & flange height can be checked w/ pressure paste or by attempting border movements and checking for displacement Dentures w/ overextended flanges or high spots on the intaglio will often cause significant inflammation - examine and adjust these areas as needed In event that the dentures are independently stable but tend to dislodge during function, a simple occlusal balancing may resolve the issue  ○ Change in basal seats of dentures is usually revealed by: Looseness and movement of the prostheses on clinical exam General soreness and inflammation Discernible loss of occlusal vertical dimension and compromised aesthetics Disharmonious occlusal contacts ○ Note: if pt has worn ill-fitting or overextended dentures for a significant period of time, they may exhibit significant tissue hyperplasia in these areas → this may be cause of denture looseness or rocking - which is why soft tissue eval is critical Tissue may need surgical reduction or, at very least, pt may need to stop using denture or wear denture w/ tissue conditioner for 1-2 weeks to allow tissue to heal Ridge resorption ○ Ridges resorb both vertically and horizontally ○ In maxilla - bone typically resorbs in such a way that denture moves up and back, which can lead to pain in anterior vestibule as flanges become overextended ○ In mandible - resorbs in such a way that denture moves down and forward Note: this is not entirely predictable & resorption patterns vary greatly from pt to pt ○ As ridge resorbs, pt’s VDO is decreases & mandible typically rotates forward Pts who have been in denture for extensive period of time will often present w/ signs of VDO loss (angular chelitis), heavy occlusal wear on denture, & may present in Class III relationship due to shifting of mandible ○ As ridge resorbs, clinical implications on denture get more pronounced We can make out decision to reline vs rebase depending on clinical observations Tx rationale (according to textbook - NOT a Dr. Wes original graphic design, womp womp) ○ Relining ○ Involves adding new layer of material to existing denture base ○ Can be performed w/out adversely affecting occlusal relationships or aesthetics of lip and face ○ Is tx of choice when minimal or moderate tissue changes are evident ○ In classic indirect (lab) reline, the ill-fitting denture is lined w/ thin layer of impression material Denture & impression material is sent off - impression material is replaced w/ new acrylic in lab Resulting denture is often slightly thicker, but is now adapted to existing ridges This can be done relatively simple, accurately, and inexpensively Rebasing ○ When moderate to severe tissue change in evident & change in VDO or occlusal relationship is noted, oftentimes a reline will not be enough to resolve issues Rebasing presents an option to better address these issues However, it is noted by the textbook that managing these issues w/out having control of the tooth position - as you would when making a denture, often results in major occlusal mods of teeth to achieve occlusal harmony ○ In other words, you may need to grind some of the teeth to nubs to get the rebased dentures to occlude properly As such, it is often preferable from a clinician’s perspective to remake dentures rather than rebase them  Impression techniques ○ Static impression technique Existing denture is used as an impression tray Denture is lined w/ elastomeric materials (such as VPS) & placed in mouth Impressions are then taken using either open or closed mouth technique ○ Closed mouth technique is least laborious typically & is preferred when using a static impression technique Modifying the denture ○ w/ either open or close mouth technique, is best to modify the dentures for use as trays ○ Large undercuts should be relieved ○ Intaglion should be relieved 1-2mm ○ Existing soft lines or tissue conditioners removed ○ Reduction of flanges as needed if are overextended ○ Can drill small escape holes in base for excess impression mateiral to escape through Closed mouth technique You should attempt to to border mold as these impressions are setting up Care should be taken not to apply too much impression material - as this can result in overly thick denture base or even increased VDO if not careful Open mouth technique Similar to almost any other impression - w/ denture acting as a tray and impression material within denture In this case, should also try to border mold when taking impression In this technique, pt’s existing centric occlusion will NOT be used In essence, we are relining the denture independent of occlusion After reline is processed, we will have to adjust and re-establish occlusion - which may need to be completed w/ a remount procedure after delivery of relined dentures ○ Functional impression technique Gained considerable support in recent years As opposed to static impression, this technique utilized tissue conditioners as impression material - which sets quite slowly (over a period of days to weeks) Tissue conditioners - examples: COE comfort, softone, etc ○ Typically self-curing resins taht set up very slowly, existing in a soft phase for extensive time before cuttting ○ Typically powder/liquid mixed, placed in intaglio of dentures & dentures are placed using closed mouth technique After initial setting after a few mins, any excess can be trimmed prn ○ After several days (10-14), impression material sets up & can then be sent to lab for removal and replacement w/ permanent resin material ○ Pt should not scrub this material excessively & should not use hard cleaners - as these are prone to degradation Denture is used over course of this period & impression material is shaped during function ○ “Chairside” technique Involves using aforementioned open or close mouth techniques, but instead of using impression material or tissue conditioner to create an impression then sending to lab, an acrylic base material is added  Dentures are then placed & the material sets up completely, creating a reline “chairside” Problem w/ this technique is materials used PMMA (material used in most conventional dentures) gets quite hot when curing ○ Other acrylics can cause thermal or chemical burns Rather than use PMMA, other materials are often used - which materials are often more porous, harder to keep clean, & less color stable These are also difficult to remove is any issues occur during the process w/ all these downsides, book does not really recommend chairside hard relines However, chairside relines w/ soft liners can be very useful - esp w/ immediate denture cases Hard vs soft relines ○ Hard relines - relines of denture w/ a permanent, hard material Typically PMMA when performed indirectly w/ lab ○ Soft relines - relines w/ a softer material, such as other acrylics or silicones Typically meant to be temporary Just how temp the liner is depends on mateiral and desired purposed Tissue conditioners can be considered a soft reline that is only meant to be in places for a few weeks Other soft lines, such as COE soft, will typically last ~3months w/ good home care Zest claims CHAIRSIDE will last up to 18 months Soft relines are excellent for placement w/in an immediate denture After initial socket closure (2-3 weeks), a soft liner can be placed w/in immediate denture w/ adjustment/replacement prn, this can typically be maintained comfy by pt until significant ridge resorption occurs, before being replaced by “perm” hard reline, using one of the previously mentioned techniques Immediate denture pts are often much more satisfied w/ their dentures after soft liner placement So why don’t we just put pts in soft line forever? Limitations in color stability, cleansibility, attachment/bond to denture, wear resistance requires more frequent maintenance Survery Crowns and RPD Retainers RPD design basics ○ Design of RPD should return arch to function as well as possible & should seek to direct forces developed during placement, removal, and function of RPD in a way that causes the least damage to remaining teeth ○ Components of a RPD that help distribute vertical loads include rest seats on tooth borne components & denture bases on tissue borne components Additionally, partial needs to stay during function - this is primarily accomplished using retentive clasps Finally, lateral forces created by retentive clasps must be counterbalanced to provide retention & to prevent damage to teeth - accomplished w/ reciprocal elements ○ RPD’s (like crowns, bridges, etc) will need a path of insertion - which will also serve as a path of removal In order to facilitate this, we may need to change contours of teeth - through creation of guide planes ○ Many diff designs for clasps, rest seats, and reciprocal arms & many ways to connect them - through both major and minor connectors Also many possible paths of insertion for our RPD - which will determine both our guide planes and our undercuts by which our retentive arms will create retention Surveying and designing ○ Dental surveyors are essential for tx planning of RPDs & survey crowns - as they help evaluate relative alignments of remaining teeth, determine optimum path of insertion, help evaluate undercuts for use w/ retentive clasps Goal is often to select the most ideal anteroposterior and mediolateral tilt to allow for all of the design elements desired to be placed w/ minimal alteration to natural teeth ○ Once surveyed, it is best practice to create a design cast - on which we can draw our partial design and communicate our design to the lab Survey crowns ○ In many cases, successful RPDs can be made on natural teeth w/ the design elements such as guide planes, rest seats, etc., made into existing teeth through minimal enameloplasty However, using a survey crown: 1 - allows for precise shaping of axial contours - as they are shaped on a cast in the lab 2 - can allow for heavier mods of axial surfaces than enameloplasty would allow ○ Additionally, if pt already needs a crown and RPD it can be favorable to design crown as survey crown - rather than simple recreate a natural tooth (only to have to modify it for partial) This is why tx planning of these cases is so critical & why these decisions must be made before putting bur to tooth Tooth mods for RPDs ○ Guide planes RPD will need path of insertion & removal - this path will have to be consistent throughout ALL teeth proximal to RPD Path of insertion is best planned and designed through use of surveyor Once surveyed, mods to the proximal surfaces of natural teeth can be made accordingly If alterations to natural tooth are greater than can be performed w/ enameloplasty, we can alter axial surfaces w/ survey crowns Rather than prepare axial surfaces of prep to long axis of tooth, axial reduction must be prepared to allow for altered contours of restoration ○ Rest seats Prepared recess in a tooth created to receive an occlusal rest element of an RPD Occlusal rest contacts the tooth & transfers vertical forces from RPD to tooth  Rest seats are spoon shaped to reduce lateral forces & should be deep enough to provide sufficient thickness of material in corresponding occlusal rest on RPD Adequate amount of tooth structure must be removed to allow for ~2mm of thickness of rest seat of RDP and for restorative material of crown It is best that survey crowns that will include a rest seat are either cast metal or PFM w/ occlusal rest in metal - as these allow for minimal additional reduction for rest seat (additional ~1mm) Should not be perfectly spoon shaped w/in prepared surface but more rounded to allow for some flexibility in rest seat location in lab as needed ○ Retentive clasps (undercuts) Elements of RPD that intentionally engage undercut surfaces of teeth Act to retain RPD - keep from dislodging during function Amount of retention is related to material of clasp, configuration and design of clasp, extent of undercut that it is placed in Depth of undercut placement can range from minimum of 0.12mm w/ cast metal clasps and up to 0.5mm w/ wrought wire clasps Goal is for retentive clasp to engage tooth only when seating or removing - should be passive at rest Additionally should engage tooth below survey line → line produced on surveyor by makring height of contour relative to planned path of insertion of restoration As long as path of insertion is not greatly deviated from long axis, preps for survey crowns should not be affected much by placement of undercuts for survey crowns Rather, the lab should design the external undercuts on the survey crown as desired independent of internal surface of crown We do NOT want to recreate a desired undercut in our crown prep - this will affect the ability of survey crown to seat If path of insertion is altered significantly, will need to mod prep to allow for sufficient material thickness (just like for guide planes) ○ Reciprocal clasps Guide prosthesis into place upon insertion and support abutments against horizontal forces exerted by flexing retentive arms during seating Must be within path of insertion and tooth may need guide planning to allow for appropriate function of these recriprocal elements Additional tooth reduction is necessary if retainer must be undercontoured w/ regard to original tooth form to accommodate reciprocal guide planes (we need to prep tooth more if crown will be flatter than original tooth) Why survey crowns? ○ These design elements have very fine margins of error and there are many factors that make a successful abutment tooth for an RPD ○ Poor design of abutment results in abutment that is either: 1 - non-retentive 2 - so retentive that it is painful to pt or damaging over time ○ Survey crowns allow for tightest control of these elements and often result in more satisfactory RPD - esp in cases w/ less than ideal abutments to begin with What is pt needs a crown and already has an RPD? ○ Need may arise to replace a survey crown under a satisfactory RPD - how do we replace the crown while making it fit the RPD? 15 ways total, we need to know 2 ○ The “pickup” impression After removing old crown & preparing tooth further prn, master impression is taken off crown prep - just as you would w/ any other tooth However, pt’s partial is in the mouth when impression is taken  Partial is removed w/ impression & is included in what is sent to lab (thus “pickup” name) Cast is then poured up, partial is placed on cast, crown is waxed & cast to match existing partial ○ Let a computer do it w/ CEREC, we can scan original crown and recreate it - as long as it is in good enough shape to start with Downside is that it is dependent on state of original crown & that the material will be milled ceramic (not as great for survey crowns) Ortho Be able to ID primary versus permanent teeth Know what permanent teeth replace primary teeth Know how to ID missing teeth Know questions at the end of the research article presented by Dr. Pryse and James Graham ○ Prevalence of pediatric obstructive sleep apnea (POSA) has increased from 3.3-9.4% in studies published before 2014 to ___ in studies published from 2016-2023 12.8-20.4% ○ In comparison, adults diagnosed w/ OSA have a worldwide prevalance of ___. 54% ○ There is ___ for depression and withdrawn/depressed symptoms in children w/ OSA. An increased risk ○ The validated pediatric sleep questionnaire (PSQ) emphasizes snoring intensity and frequency, witnessed apnea, ___, morning headaches, low growth, and attention deficit symptoms. All of the above - mouth breathing, daytime fatigue, bed wetting ○ ___ can diagnose SDB for adults or children. Only a physician ○ The first line of treatment for pediatric OSA (POSA) is usually ___ however, numerous studies have demonstrated that it may not be as successful as once thought. tonsil/adenoid (T&A) surgery ○ A second line treatment to treat POSA is ___. Positive airway pressure therapy (PAP), most often utilizing continuous positive airway pressure (CPAP) ○ Decompressing the TM joints with a removable lower appliance at a physiologic position (sibiliant phoneme registration/phonetic bite) has been shown to increase pharyngeal airway volume and decrease collapse. True ○ Myofunctional therapy for POSA has been shown to reduce AHI by ___. 62% ○ Myofunctional therapy for POSA is ideal primary treamtent for ___ patients exclusively. 2- to 5-year old