Periodontics II - Midterm 01

  1. Ridge reduction following extraction
    • Schropp, et. al. 2003
    • reduction of half the ridge width within a year
    • majority of reduction occurs within the 1st 3 months
    • loss in width is much greater than the loss of height
  2. Post extraction bone grafting
  3. Modified Plaque Index
    • Modified from Podshadley Index
    • 4 first molars and #8 and #24
    • Buccal surface for upper teeth
    • Lingual surface for lower teeth
    • Each surface is divided into three equal vertical segments, and the middle one is further divided into three equal segments, hence 5 areas per surface/tooth
    • Number of areas with plaque/30
  4. Bleeding Index
    • Modified from Muhleman/Carranza Text Bleeding Index
    • # of bleeding probing/total # of probing
    • total # of probing = total # of teeth probed x 6
  5. Curretage
    cleaning out ulcerated epithelium of the pocket
  6. Scaling and Root Planing
    • Goal is to get the bleeding index to <10%
    • Elimination of periodontal pathogens, toxins, calculus and the associated local contributing factors.
    • Provide a biologic compatible root surface.
    • Reduction of periodontal pockets to a measurement that is conducive to periodontal health. (Pockets <5mm)
    • Improve the tissue quality & obtain healthy gingival tissue.
  7. RCT
    • Done after S/RP
    • Done ASAP (before S/RP) if pain present
  8. Restorative -caries
    • Done after S/RP
    • Done ASAP (before S/RP) if caries is deep and waiting may lead to RCT
  9. Temporization
    • Acrylic temp or Essix appliance for 1-2 teeth
    • Interim partial or flipper, not as desirable
  10. Techniques for temp stablization
    • intra-coronal splinting - bad technique; breaks down, causes decay; drill and sprint
    • extra-coronal splinting - no drilling
    • ligature wire
    • night guard or similar occlusal device - for parafunctional habit, also for splinting and treating secondary TFO ; on lower arch, easier to tolerate; on arch w/ most missing teeth to maximize occlusal contacts if many teeth missing. Minimal separation, maximal contact
    • assess treatment results to date, patient compliance, tissue response (quality), plaque index, bleeding index, and the need for periodontal surgery.
    • If pockets depths >= 5mm or >, especially when vertical defects are present, consider periodontal surgery
    • Evaluate the necessity to treat Muco-gingival defects or structural issues.
    • Ideally 4wks after last quadrant of S/RP
  12. Characteristics of LAP
    •  Circumpubertal onset
    •  1st. molar and/or incisor involvements; Primary dentition may be involved
    •  Robust serum aby response to infecting agents.
    •  Systemically healthy
    •  Minimal inflammation/plaque/calculus
    •  Rapid progress
    •  PMN dysfunction
    •  Familial distribution
    •  Hyperresponsive macrophage phenotype, including
    • ↑PGE2 & ↑ IL-1β
    •  May be self-arrested
  13. Characteristics of GAP
    •  Usually affecting individuals <30y/o
    •  Generalized severe bone loss
    •  Poor serum aby response to infecting agents
    •  No systemic diseases
    •  PMN dysfunctions
    •  Familial distribution
    •  Cigarette smoking is a risk factor.
    •  At least some LAP cases may progress to GAP. Early detection may involve LAP cases with low titers of Aby against A. a.
  14. Perio desease vs. cardio disease and stroke
    • Perio pockets hold G- bacteria, LPS and pro-inflammatory cytokines, MMP involved in tissue breakdown, which may join the general circulation.
    • Monocytes (elevated level in perio disease) go into the vessels, if there is damage to the vessels. They engulf LDL, become foam cells when in the endothelial wall, and can produce more cytokines and promote inflammation, stimulate deposition of collagen, narrowing of lumen of major arteries which compromise blood flow. Arethoma may burst, come in contact with smooth muscle, blood clots can form. Complete blockage results in stroke or infarction.
    • P. gingivalis can invade endothelial cells, adhere to and invade heart cells and aortic endothelial cells, causing increased blood lipid level, atheroma formation and calcificaltion
    • Periodontal disease may act as a trigger for systemic inflammation while clinically evident infection is absent.
    • PCR of human carotid atheromas - positive for periodontopathogens, eg. A.a, P. gingivalis, T. forsythensis, P. intermedia.
  15. Perio desease vs. cardio disease and stroke
    • C- reactive protein is high in both diseases
    • LDL increases secretion of proinflammatory cytokines
    • from monocyte/macrophage – leading to atheroma formation (atherosclerosis) and periodontal destruction.
    • Contain systemic inflammatory component.
    • Shared aspects in pathogenesis - C-reactive protein (CRP), Proinflammatory mediators, Fibrinogen, LDL, WBC count, infection, etc.
  16. Is A.a associated with LAP
    • High numbers in periodontal lesions in LAP patients.
    • Low numbers in healthy sites in the same patients.
    • Low numbers in normal people w/o LAP.
    • >90% LAP patients show high titers of antibody
    • to A. a. Crevicular fluid titers higher than serum.
    • Elimination of A.a results in healing & improvement of diseased sites
    • Persistence of A.a results in unresolved periodontal lesions
    • Diagnosis of LAP was more likely in a subject positive for A. a
    • However
    • - Not all individuals (40-50%) with A.a. get LAP
    • - Not all LAP patients have detectable A.a.
    • - Not all LAP patients have depressed PMN chemotaxis
    • - Not all individuals with depressed PMN chemotaxis develop LAP
    • - Presence or absence of A. a could not discriminate subjects w/ LAP from those w/ chronic periodontitis
    • - Any A.a. positive patients are three times more likely to be suffering from chronic perio than from LAP
  17. Characteristics of A.a.
    • Gram negative, non-motile rod
    • Can penetrate and reside in gingival epithelial and connective tissues - binding to collagen & fibronectin.
    • Parent-to-child or inter-spouse transmission reported.
    • Not found in tongue, cheek, mucosa, palate and dentures in edentulous individuals
    • Unresponsive to local antibiotics
  18. Virulence factors of Aa:
    • LPS
    • - Component of the outer membrane
    • - Immunological activities - pro bone resorption, pro-inflammatory mediators (cytokine, PGE2) production
    • Leukotoxin
    • - toxicity varies by strains
    • - Highly leukotoxic A.a. mostly found in LAP patients
    • - Most LAP patients harbor highly leucotoxic A.a.
    • - Most A.a from diseased sites of LAP patients are highly leucotoxic
    • - Most A.a isolated from healthy sites are nonleucotoxic.
    • - Toxic to erythrocytes
    • Surface Associated Material (SAM)
    • - A protein loosely bound to the outer surface of the external membrane pro bone resorption.
    • - Stims PGE2 and collagenase production from bone cells
    • - 1000X more potent than LPS as bone resorption agent
    • - Stimulate IL-6 production which strongly stims osteoclast formation
    • Chemotaxis-inhibiting factor
    • B-Lymphocyte-activating factor
    • Epitheliotoxin
    • Collagenase
    • Fibroblast-inhibiting factor
  19. Brushing techniques
    • Remove plaque, clean teeth, stim gingival tissue, apply fluoride.
    • Hard tooth brushing may cause cervical abrasion
    • Horizontal brushing can cause gingival recession
    • Vibratory: Stillman, Charters, Bass
    • Roll: Modified Stillman
    • Circular: Fones
    • Horizontal: Scrub
    • Bass Technique:
    • - Sulcus cleaning method
    • - 45 degree angle along gumline, touching tooth and gumline, vibrating back and forth and rolling, three teeth at a time. Tilt vertical and go up & down for the back of front teeth. Biting surface - back & forth scrubbing.
    • - Disadvantages: requires dexterity, can cause gingival abrasion
    • Stillman Technique:
    • - Indication: for areas with progress gingival recession and root exposure to prevent further tissue destruction
    • - Bristles are placed half in the sulcus and half on the gingiva. Everything else is similar to Bass technique
    • Modified Bass Technique
    • - After circular motion, the bristles are swept up to the occlusal surface. Requires even more dexterity
  20. Purpose and Objectives of Phase 1 therapy
    • Preliminary non-surgical treatment
    • Elimination of perio pathogens, toxins and calculus and the associated local contributing factors
    • - microbes - Localized drug delivery
    • - plaque and calculus - scaling and root planing
    • - overhang, poorly fitting prosthetic devices, hopeless teeth (can affect the teeth next to it).
    • - Calculus removal is important: semi-permeable, absorb toxins, retentive site for plaque, make plaque removal more difficult
    • - plaque and calculus from class 2 and 3 furcations - Cavitron (CAUTION with pacemaker patients)
    • - S/RP - Limit to 5mm
    • Restore healthy gingival tissue
    • Shrink perio pockets
    • Provide a biologically compatible root surface
    • Address chief complaint
    • Control the disease / inflammatory response
    • Eliminate infection and pain
    • Remove hopeless teeth
    • Treat occlusal problems
  21. Tarnow's black triangle
    • the effect of the distance from contact to crest of bone on the regrowth of interproximal papilla
    • As distance increases, likelihood to have papilla present decreases
    • - 3-4mm, 100% will have papilla present
    • - 5mm, 98% will have papilla present
    • Not ideal if longer than 5mm
    • - 6mm, 56% will have papilla present
    • - 7mm, 27% will have papilla present
  22. How much time does it take for the tissue to heal after scaling and root planing
    • 1-2 weeks for epithelium
    • at least 4 weeks for connective tissues to heal
    • Depends on the degree of inflammation
    • Ideally, Phase I Evaluation should take place 4 weeks after the last quadrant of scaling and root planning.
  23. ADA Guideleine for proper clinical studies dealing with plaque control and or gingivitis:
    • Representative - Characterisitics of the population represent typical product users
    • Normal use plus control - Active product used in normal regimen and compared to a placebo control, or wherever possible, an active control
    • Design - Crossover or randomized parallel design
    • Duration - Minimum of 6 months’ duration
    • Microbial sampling - estimate plaque quantitatively, to complement indices which measure plaque control quantitatively
    • Timing - Plaque and gingivitis scoring and micro sampling conducted at baseline, 6 months and at an intermediate time period
    • Safety micro - As demonstrated by micro profile, no pathogenic or opportunistic microorganisms develops over the course of the study
    • Safety drug - Toxicological profile includes carcinogenicity and mutagenicity assays in addition to generally recognized tests for drug safety
  24. Which substances are Quaternary Ammonium Compounds and what they are used for?
    • Prohealth – Cetylpyridinium chloride (CPC). E.g. Cepacol, Scope.
    • Reduction in plaque (14%) and Gingivitis (24%)
    • Mechanism
    • - cell permeability --> cell lysis (same as CHX)
    • - decreased cell metabolism
    • - decreased ability for bacteria to attach
    • Cationic (teeth and plaque are anionic; Activity altered by anionic substances found in dentrifices, same with CHX)
    • Low substantivity
    • High safety
    • Side effects: staining, burning sensation and possible calcified deposits
  25. FDA-Approved Products for Periodontal Diseases
    • Total® Colgate - Triclosan and fluoride toothpaste
    • Prohealth® (Crest and Total Colgate Mouthwash) - Cetylpyridinium chloride (CPC)
    • Listerine® - Essential oils
    • Peridex/Perioguard® - Chlorhexidine mouth rinse, prescription
    • PerioChip® - Chlorhexidine chip
    • Arestin microspheres® - Tiny round particles with minocycline
    • Atridox - doxycycline gel squirt under the gum
    • Actisite - Tetracycline fiber, stuck under the gum, no more used
    • Periostat® - Low dose doxycycline tablets, for host modulation
  26. Chemotherapeutic components of mouth rinses
    • Peridex/Perioguard® - Chlorhexidine
    • Listerine® - Essential oils; 25-35% plaque and gingivitis reduction; >20% alcohol, highest among all mouthrises
    • Hydrogen peroxide – detracts from reliable indicators of perio diseases like BOP and can lead to dysplasia
    • Cepacol, Scope and Prohealth – CPC, Quaternary Ammonium Compounds
    • Sanuinarine (Viadent) - benzophenathradine (derived from a blood root plant, binds to bacterial cell surface to prevent aggregation and binding). mouthrinse contains 11.5% alcohol, had to use 4x a day, may cause leukoplakia which is precancerous
  27. What is Peridex, how is it used and what are the side effects?
    • Chlorhexidine mouthrinse
    • The best for plaque reduction, similar to Listerine for gingivitis reduction.
    • High substantivity; 30% retained, released over 8-12 hr, low concentration at 24hr, prolonged bacteriocidal effect
    • Mechanism of action: Digluconate (cationic attracted to the bacterial cell wall, and anionic binds to pellicle and salivary glycoprotein), causes permeability changes and eventually cell lysis.
    • Effective against G+, G- and yeasts, count decreases 80-90% and returns to baseline 48hr later
    • Great for people who are really sick, geriatrics, ortho patients, physically or mentally handicapped patients
    • Side effects:
    • - Yellow brown staining in gingival 1/3 and interproximally, and on the tongue, related to tannins, discolors composites, professional prophylaxis
    • - Bitter taste
    • - Dulling of taste sensation
    • - Rare desquamative lesions
    • - Increased calculus formation (but decreased plaque)
  28. Short Term Clinical Applications of Chlorhexidine
    • Prior to surgery to limit bacteremia
    • Following oral surgical procedures
    • Prevention of “dry socket”
    • Following introduction of immediate dentures
    • Adjunct to plaque control
    • Denture stomatitis
    • Apthous ulcers
    • Oral infections (ANUG, HIV-G, HIV-P)
  29. CHX Intermittent Short Term Application
    • Prolong interval between maintenance visits
    • Physically handicapped and mentally retarded
    • Prevention of repeated denture stomatitis
    • Patients with history of high caries activity – high levels of S. mutans
    • Prosthetics – abutment teeth with reduced periodontal support
    • Dental implants
  30. CHX – Long Term Application
    • Serious medical problems
    • - Leukemia
    • - Agranucytosis
    • - Kidney failure
    • - HIV infection
    • - Transplants
    • Patients treated with cytotoxic drugs
    • - Immunosuppressive drugs
    • - Radiation therapy
    • Physically handicapped
    • - Rheumatoid arthritis
    • - Scleroderma
    • - Disturbance of motor activity
    • Patients undergoing orthodontic therapy
    • - Intermaxillary fixation
    • Geriatric patients
  31. Know the effects of fluoride and the benefits of different types of fluorides:
    • Anti plaque properties (PI)
    • Highly toxic - caution for children and mentally challenged patients
    • SnF alters bacterial aggregation and metabolism, lowers plaque and gingival index, lowers gingival inflammation and bleeding index
    • Sn ion may be the active agent
  32. Toothpastes to recommend, which components are the detergents and the humectants:
    • Colgate total: triclosan, NaF; helps w/ gingivitis
    • Crest Pro-health: SnF, good for preventing caries
    • Humectant - retains the moisture, various sugar alcohols
    • Detergent - the surfactant, sodium lauryl sulfate (SLS)
  33. Desensitizing agents?
    • Potassium nitrate (nerve calming) - current sensodyne
    • SrCl2 works as a barrier, also desensitizing, old sensodyne (wiki)
  34. Indications of systemic antibiotic therapy for periodontitis:
    • Patients exhibiting continuous loss of periodontal
    • attachment despite diligent mechanical conventional periodontal therapy
    • - Aggressive perio
    • - Refractory case
    • - Medically compromised patient
  35. Compliance rates for taking antibiotics:
    • Qd – 73%
    • Bid – 70%
    • Tid – 52%
    • Qid – 42%
  36. Know which antibiotics are used by themselves and in combination to treat perio disease:
    • Tetracycline (not really used) – quick resistance
    • - 250 mg, QID
    • - Unstable with food, cannot use if pregnant, on Coumadin, seizure medications, contraceptives
    • - Inhibit protein synthesis in bacteria
    • Doxycyclines
    • - 100 mg QD or 50 mg BID (high patient compliance)
    • - Not altered by calcium or antacids
    • - Interrupt oral contraception
    • - Inhibit protein synthesis in bacteria; may inhibit gingival collagenases!
    • - Used with A.a. perio infections
    • Metronidazole
    • - Effective against P. gingivalis and P. intermedia
    • Erythromycin
    • - only if allergic to penicillin or pregnant (will not cross the placenta)
    • - Complications with preferential metabolism with other meds (patient can die)
    • Azithromycin / zithromax
    • - 5 day rx, gives 10 day coverage
    • Amoxicillin
    • - intolerance
    • - Localized infection - if intolerant, doxycycline or azithromycin
    • - Spreading infection - can “piggyback” with metronidazole for refractory cases, or if no improvement after 2 days; predictable eradication of A.a. when in combination and suppression of P. gingivalis in LAP and adult perio; if intolerant, use zithromax
  37. What is Periostat and what does it do, when is it used and why?
    • 20mg BID of doxycycline hyclate (subantimicrobial dose of doxycycline, SDD – eliminates risk of developing resistance)
    • Not acting as a antibiotic, anti-inflammatory-ish, stop the destruction of bone, not to kill the bacteria (wil be taken off by mechanical mechanisms)
    • Used in conjuction w/ S/RP or dental prophy
    • Significantly reduces collagenase activity, improves attachment levels, reduction in pocket depths, and bleeding index
    • Periochip = CHX (want probing depth of 5mm, worked best in 7mm)
    • Aresin = minocycline hydrochloride microspheres
  38. Know the effect of occlusion on periodontal disease – 2 studies were presented
    • In healthy periodontium this will increase the mobility of teeth but not cause pockets
    • TFO may occur in conjunction with or independent of inflammatory perio disease, each condition may be treated separately
    • TFO may occur in an intact periodontium that has been reduced by inflammatory perio disease
  39. Reinhardt study:
    • Areas of greatest compressive stress were near the alveolar crest and in the apical half of the root for all loads at all bone levels
    • Reduction of the alveolar bone height had little effect on the degree of periodontal ligament stress until 60% of the bone support had been lost
  40. Lindhe's study
    • High crown placement with an orthodontic appliance (Scandinavian Group)
    • Inflammation extended beyond the marginal gingiva
    • - Widening of the PDL
    • - Continuous bone loss associated with periodontitis
    • - Merging of the two zones
    • - Increases perio breakdown around a tooth exposed to plaque and jiggling trauma
    • - Inflammation inhibits the potential for bone regeneration
    • - Apical proliferation of the dentogingival epithelium (loss of attachment)
  41. Polson's study
    • Teeth separated by a wooden or elastic material wedged interproximally to replace tooth
    • - Everything was the same as the above study except for there was no additional loss of connective tissue attachment
  42. Conclusions of studies:
    • In the absence of plaque the bone loss caused by occlusal trauma is reversible and there is functional adaptation of the periodontium
    • TFO does not cause pockets or gingivitis
    • The presence of plaque induced inflammation has a negative affect on bone regeneration after the removal of occlusal trauma
  43. Know the goals of occlusal therapy and the effect of TFO on the periodontal ligament and the signs of TFO
    • Clinical Signs and symptoms of TFO
    • - Tooth mobility (PDL is stretched)
    • - Tooth migration or shift in jaw movement
    • - Fremitus
    • - Presence of wear facets
    • - Chipped enamel or crown/root fracture
    • - Tooth pain on chewing or sensitivity to percussion
    • - Tenderness of muscles of mastication or signs and symptoms of TMD
    • Radio changes:
    • - Disruption of lamina dura (reversible)
    • - Change in the density of bone
    • - Widening of the PDL space
    • - Radiolucencies in furcation area or apex of vital teeth
    • - Radiolucency at the apex of a vital tooth
    • - Root resorption (not reversible)
    • Therapeutic Goals
    • - Elimination or reduction of tooth mobility
    • - Establish or maintain a stable, reproducible intercuspal position
    • - Establish an occlusion with acceptable phonation and esthetics
    • - Develop a comfortable occlusion
    • - Provide freedom of movement to and from the intercuspal position, including all excursive movements
    • - Provide efficient masticatory function
    • - Eliminate or modify parafunctional habits
  44. Glickman’s zones with respect to TFO
    • Zone of irritation:
    • - Initial plaque region
    • - demarcated at the level of the transseptal fibers
    • - Includes marginal and interdental gingiva
    • - Gingival inflammation cannot be induced by trauma to occlusion
    • - Gingival inflammation is a result of irritation from microbial plaque
    • Zone of Co-Destruction
    • - Coronally demarcated by the transseptal fibers ad dentoalveolar collagen fibers
    • - Includes the PDL, cementum and alveolar bone
  45. What are and how do you treat primary TFO and secondary TFO
    • Primary TFO
    • - Primary etiologic factor in perio destruction produced around teeth with previously healthy periodontium
    • - Caused by Restoration in hyper occlusion, Restoration that creates excessive forces on the abutment teeth and opposing teeth, Ortho movement of teeth into functionally unacceptable positions (occlusal discrepancies)
    • - Want to stabilize everything up to a class 2 mobility by splinting the teeth, maybe with a nightguard, or you can do selective grinding
    • Secondary TFO
    • - Adaptive capacity of the tissues to withstand occlusal forces by bone loss resulting from marginal inflammation
    • - Normal periodontium with bone loss
    • - Marginal periondontitis with bone loss
    • - Splint the teeth instead of selectively grinding if the mobility is due to the loss of attachment.
  46. If tooth is mobile what should you do first?
    Probe it, determine if it is a perio problem or an TFO problem
  47. Know the order of developing a treatment plan with respect to the different phases of treatment:
    • Phase III (replacement dentistry), II (surgical treatment), then I (preliminary treatment)
    • After the case is complete then the patient is on a maintenance program (phase IV).
  48. Know the outcome of the studies concerning Phase I Therapy presented in the lecture
    • No-name study
    • - If no class II or class III furcation, no difference in gingival response when you SRP by hand or if you SRP by cavitron
    • - If you have class II or class III furcation, the cavitron is superior (performed better and is more effective)
    • Stambaugh
    • – with 7 teeth that have avg pocket depth of 6-9mm, avg SRP time is 25-39 mins – too long
    • - Average pocket depth instrument free of calculus is 3.73mm.
    • - Instrument limit average is 5.52mm.
    • - If you have a pocket greater than 5mm, you might not be able to remove all the calculus (ability to remove is unpredictable)
    • Cobb
    • – SRP effects on perio disease
    • - The number of pockets 4mm or greater in depth was reduced by 52-80%; - Up to 80% reduction in bleeding on probing
    • - up to 2-3mm mean pocket depth reduction; 4-6mm pockets, 1.26mm mean pocket depth reduction (add 1.26mm of attachment); 7mm or deeper pockets, 2.16mm mean pocket depth reduction.
    • Schropp
    • - Within a year of the extraction, reduction of half the ridge width.
    • - The majority of reduction occurs within the 1st three months
    • - The loss in width is much greater than the loss of height
  49. What is the phase 1 evaluation? what should be the values of the bleeding and probing indices be?
    • Assess the treatment results to date, patient compliance, tissue response to the therapy, plaque and bleeding indices. To confirm or modify the presumptive diagnosis. To identify additional therapeutic needs. If pocket depths remain at 5 mm or grater might want to think about perio surgery
    • Bleeding index: 0 is ideal; 10% or less is desirable
    • Plaque index: 0 is ideal
  50. Types of splints and which ones to avoid and which ones to recommend
    • Splints are used for temporary stabilization
    • Intra coronal (bad technique)
    • extra coronal (good because you don’t have to cut the teeth at all)
    • ligature wire
    • nightguard (for parafunctional habits, secondary TFO, and splinting teeth)
  51. What is an open bite, closed bite, VDO, VDR and free way space
    • VDO = VDR – Freeway space; teeth occluding
    • VDR = VDO + freeway space; jaws separated and muscles relaxed
    • Freeway Space = distance from VDR to VDO
    • Open Bite: VDO is increased and the freeway space is decreased
    • Closed Bite: “collapsed”, no posterior support; decreased VDO, increased freeway space
  52. Posselt’s Envelop of Motion:
    • 3D concept of mandibular movements starting with a point on the lower incisor
    • A combination of movements in all 3 planes: sagittal, horizontal and frontal
    • Superior surface of the envelop is set by tooth contacts and the other borders are set by the TMJ
    • The envelop differs from person to person, but has the same shape
  53. The rules on selective grinding
    • Want the forces to be shared equally among all teeth and produce a physiologic and mechanically sound occlusion
    • A prematurity is an occlusal contact that diverts the mandible from a normal path of closure or movement
    • Only do it when the clinic problem is correctly diagnosed
    • - Primary Trauma From Occlusion
    • - TMD problems – may be a factor in the etiology
    • - Palliative Treatment – hot tooth from an endo or perio abscess or physical trauma. The tooth is usually extruded, due to the inflammation of the PDL. Always adjust the occlusion on the specific tooth and maybe temporarily stabilize the tooth, if mobile.
    • - Establish MIP pinpoint contacts in centric.
    • - Establish proper excursive positions, particularly anterior guidance
    • - Redirect the occlusal forces to enable optimum dissipation of forces along the long axis of each tooth.
    • - Permit the mandible to move freely, without causing destructive tooth contacts or abnormal muscular activity
    • Excursive interferences:
    • - Protrusive: Premature posterior contact prevents or affects anterior guidance
    • - Working side: Interferences between FOA’s of supporting cusps and guiding inclines
    • - Balancing Side: Interferences between the lingual incline of the lower buccal cusp and the buccal incline of the upper palatal cusp
    • Eliminate centric pre maturities
    • - The mesial aspect of the first premolar is the most common initial centric contact prematurity
    • - If you have a contact in centric that is premature and in excursive, then you grind the cusp tip
    • Correct the lateral excursions:
    • - Balancing: Buccal inclines of the max lingual cusps and lingual inclines of mandibular buccal cusps
    • - Working: Lingual inclines of the max buccal cusps and buccal inclines of mandibular lingual cusps
    • Correct the protrusive position
    • - Check centric holding points and narrow the contacts to pinpoint contacts
    • - Recheck the occlusal scheme
    • - Contacts should be in central fossae and marginal ridges and on the supporting cusps
    • Polish all teeth
  54. Where are the balancing side contacts located on the teeth
    • Balancing side contacts should not be present and if they are they should only be between the supporting cusp inclines
    • Second molar on the nonworking side tends to receive more interference on the nonworking side than the other teeth
  55. the ideal occlusal schemes for working, balanced and protrusive and FOA’s
    • - see above question about selective grinding
    • - FOAs should be 1mm away from their respective occlusal lines
  56. Know the different planes of occlusion – Landmarks
    • Imaginary curved plane formed but the incisal edges of the anterior teeth and the occlusal surfaces of the posterior teeth. It follows the natural curvatures of the teeth and curves higher in the back due to the Curve of Spee (the anterior/Posterior curvature of the occlusal surface) and relates to the Curve of Wilson, which is the medio-lateral curve.
    • Line should be parallel to the intra pupillary line and perpendicular to the nasion-philtrum line
    • Campers line (ala-tragus line) - Line from the inferior border of the ala of the nose to the superior border of the tragus of the ear, should be parallel
    • Frankfurt line (Horizontal plane) - Line from inferior margin of the orbit to upper margin of external auditory meatus
    • Fox plane - Device used to establish the occlusal plane (ala tragus line) with wax rims on denture reconstruction
Card Set
Periodontics II - Midterm 01
Periodontics II - midterm 01 0929 Phase I Therapy (part) Study guide