Prosthodontics1. Arrange the following provisional materials from most desirable to least desirablein terms of temperature increase during setting reaction: a. Trim, Jet, Firmit b. Jet, Firmit, Trim c. Firmit, Jet, Trim d. Firmit, Trim, JetA: The answer is: d. Firmit, Trim, Jet. In general, the greater the size of the monomermolecule, the less is the exothermic heat of reaction on setting and mechanical propertiesis accomplished mainly through the filler. An increase in filler content reduces therelative amounts of exothermic heat and contraction while increasing the strength of theset material.For light-activated systems the amount of filler is determined by the manufacturer; for theother systems it is desirable to incorporate as much filler as possible without interferingin the handling or manipulation characteristics of the material.Contemporary Fixed Prosthodontics, 2nd ed. Rosenstiel et al
2. You are selecting a shade for a PFM crown to restore tooth #8. The patient is a 49year old actress with an exacting personality and she said the most important resultfor her would be to have the new tooth “blend in” so as to be undetectable. Whichorder should the following parameters be selected in order to best achieve this goal?a. hue, value, chromab. chroma, value, huec. hue, chroma, valued. chroma, hue, valueThe answer is C. hue, chroma, value. You would probably also choose supplementalcolors and characterization to give the tooth a natural appearance.It is very important to remember what each of these terms describe:Hue = the variety of a color, shade, or tint. The hue of an object can be red, green,yellow, and so on and is determined by the wavelength of light reflected and/or lightobserved. In the Vita Lumin shade guide, A1, A2, A3, A4 are said to be similar hue asare the B,C, and D shades. The region with the highest chroma (i.e., the cervical region ofthe canines) should be used for the initial hue selectionChroma = the intensity of a hue. The terms saturation and Chroma are sometimes useinterchangeably. Imagine a bucket of water to which 1 pint of latex paint is added. Thesaturation or Chroma is low. Adding a second pint of paint increases the Chroma, and soon, until the solution is almost all paint and a High chrome results.Value = the relative lightness or darkness of a color or the brightness of an object. Thebrightness of any object is a direct consequence of the amount of light energy that theobject reflects or transmits. The value for a given tooth can be determined WITH ASECOND COMMERCIAL SHADE GUIDE whose samples are arranged in order ofincreasing lightness.Contemporary Fixed Prosthodontics, Rosenstiel, et al. pp 489-494
3. Which of the following statements regarding custom trays is, (are) true?a. There is a primary sources of error which is eliminated: stresses during removal.b. Although reducing the bulk of an elastomeric impression material increases itsaccuracy, the opposite is true for reversible hydrocolloid impression materials.c. Light-polymerized materials, when used for custom trays offer the advantage ofconvenience because a storage period of 24 hours is not needed to allow for thecompletion of poloymerization.d. Even slight flexing of the custom tray will lead to a distorted impression which isusually undetectable until one attempts to seat the restoration.e. All of the aboveAnswer: e. all the above
4. When do you reline a distal extension RPD? 1. When the indirect retainer lifts from it’s rest seat upon digital pressure to the distal Extension 2. When a wash of alginate appears on the buccal shelf area more than .5mm thick. 3. If the natural dentition fails to pierce 2 pieces of 28 gauge soft green wax placed over the denture teeth while the remaining natural teeth in opposition are making firm contact. 4. If rotation and settling of the distal extension base or bases is obvious when alternate finger pressure is applied on either side of the fulcrum line. a. 1,3 b. 1,4 c. all of the above d. 1,2,3 The answer is: C A wash of alginate with 1 scoop of alginate to 2 measures of hot water will provide a mix that is thin enough to not displace soft tissues and yet set quickly. When applying pressure to the most posterior aspect of the denture base, the amount of space under the indirect retainer is an indicator of the amount of space to be found under the denture base. Some clinical judgment is essential here because the length of the distal extension base affects the amount of movement, as does the distance from the indirect retainer to the fulcrum line.Clinical Removable Partial Prosthodontics, Third ed, Phoenix et al pp 463-464McCracken’s Removable Partial Prosthodontics ninth ed. Pp 449.
5. Which of the following features regarding mutually protected occlusion are true?1. The anterior maxillary teeth and anterior mandibular teeth together guideexcursive movements of the mandible.2. No posterior occlusal contacts occur during lateral or protrusive excursions.3. The posterior teeth come into contact only at the end of each chewing strokeacting as stops for vertical closure when the mandible returns to it’s intercuspalposition. a. 1 b. 1,2 c. 1,3 d. all the aboveThe answer is: DThe study of occlusion can historically be broadly categorized into three categories:-Bilaterally Balanced-Group Function-Mutually ProtectedRecently, the emphasis in teaching fixed prosthodontics and restorative dentistry has beenplaced on the concept of mutually protected occlusion. More recent investigations thatfocus on the neuromuscular physiology of the masticatory apparatus are supportive of theadvantages associated with a mutually protected occlusal scheme. A subset of thisscheme would be canine guidance or cuspid rise.Contemporary Fixed Prosthodontics, 2nd Ed. Rosenstiel et al
6. Which of the following are true concerning casting metals?1. Patients cannot develop a nickel allergy from Jelenko’s “Genesis II”.2. Nickel allergies are more common in males.3. Rexalloy, and Rexillium II, are examples of nickel free alloy.4. Nickel is a noble metal. a. all the above are true b. none are true c. 1,2,3 are true d. 3,4,5 are true e. 1 onlyThe answer is E, only 1 is true. Jelenko’s “Genesis II” is a metal alloy without nickel in it-thus no chance for a nickelallergy. Females are said to have Nickel allergies 9%, and males .9%. (CAPT Beattylecture). He stated that you can’t give them a nickel allergy, you just may get a reactionto an alloy with nickel in it if they are already sensitive. The Nickel replaces gold in somebase metal alloys. It is a base metal. It increases the CTE-Coefficent of thermalexpansion, it also has an anti-corrosion characteristic, and may be carcinogenic. (page117 of Fixed Pros Syllabus). Rexalloy and Rexillium II, are examples of nickel alloys,with Rexalloy being 67% Ni, 14% Chromium, Rexillium=76% Ni, 14% Cr. (page 127 ofFixed Pros Syllabus.
7. Which of the following are true concerning A-P strap facts?1. The A/P palatal strap has limited applications in maxillary partial denturedesigns.2. The posterior strap should be slightly round and 6 mm. wide.3. The strap should never be placed on moving tissue. And should cross the midlineat a right angle not on a diagonal.4. A maxillary torus is a contraindication to the A-P palatal strap design.5. Flexure is almost non-existent in the A-P design.6. It is usually used for Kennedy class II and IV’s. a. all the above are true b. none are true c. 1,2,3 are true d 2,4,6 are true e. 3,5,6 are trueThe answer is FThe A/P palatal strap design can be used in almost any maxillary partial denture design.Thus 1. is false. The posterior strap should be flat and a minimum of 8-12 mm wide. Thus2 is false. They should be located as far posterior as possible but NEVER on moveabletissues. And they should cross the midline at a right angle; the tongue will not appreciatean asymmetric appliance as readily. So #3 is true. An inoperable maxillary torus may notallow one to use an A-P design but some tori are negotiable. So #4 is false. Flexure ispractically nonexistent as each component braces the others against possible torque andflexure. So #5 is true. And finally the A-P strap design is most often used for Class II andIV Kennedy classes. With the single wide palatal strap used for the Kennedy Class III’s.SOURCE: McCRACKEN’S REMOVABLE PARTIAL DENTURES page 52-54.
8. Which of the following is/are a likely cause of sore spots on the ridges from bothdentures after delivery? a. Inaccurate denture base b. Malocclusion c. Excessive peripheral seal d. Overextension of the borders e. Excessive vertical dimensionThe answers are a,b,e.A localized sore spot on the ridges can be caused by faulty occlusion, a resin spicule oran inaccurate denture base. If a malocclusion exists then a patient remount will beneeded. For excessive vertical dimension, treatment= patient remount to lower VDO, ormake new Complete Dentures. For inaccurate denture bases you can reline or rebase ormake new dentures. I don’t think you can ever have too much peripheral seal, and anoverextension of the borders will give you sore spots in the vestibule not on the ridges. Ref. CAPT Van der Creek Complete Denture Syllabus. p. 113-Troubleshooting.
9. What percentage and type of patient’s have clicking and what percentage havecrepitus?1. Generally about 40-75% of the population have one sign of joint dysfunction. It ispossible that joint sounds can be found in 50% of the non-patient population2. Several studies report that progression of intracapsular disorders as determinedby joint sounds only occurs in 7-9% of patients.3. de Leeuw study showed that sounds persisted in 54% of patients who hadnonsurgical management of intracapsular disorders-yet none had any discomfort ordysfunction.4. Men usually have more symptoms such as headaches, clicking, TMD tendernessand muscle tenderness.5. Signs and symptoms in kids’ increases in frequency with age, joint sounds can beheard 17.5% of the time. The clicking can come and go over a five year period. A. 1,2,3 are true B. All are true C. 1,2,3,5 are true D. 3,4,5 are trueThe answer is C. All are true except 4Women usually have more symptoms such as headaches, clicking, TMD tenderness andmuscle tenderness.Crepitus is defined as multiple, rough, gravel-like sound and described as grating andcomplicated. Joint sounds of a single event of short duration are known as clicks. If thejoint sound is loud it is referred to as a pop. Pain in the TMJ is referred to as Arthralgia-the pain originates from the nociceptors located in the soft tissue surrounding the joint. .Joint sounds appear to be much more resistant to therapy and do not always indicate aprogressive disorder.REFERENCE: Okeson Orofacial Pain p. 116-118.
10. Which of the following is/are true concerning Kennedy’s/Applegates rules?1. Kennedy class 1 involves bilateral edentulous areas posterior to the natural teethwhile a Class II has a unilateral edentulous area posterior to the natural teeth.2. Kennedy Class 3 always has one unilateral edentulous area with teeth posteriorto it. A Class 4 has a single edentulous area crossing the midline and anterior tonatural teeth.3. You may have up to 2 mods only in a Kennedy Class 4 case.4. If a second or third molar is missing and is not to be replaced it is not consideredin Applegates rules. If to be replaced it will determine the class.5. Modifications are those areas other than the those that determine theclassification and are designated by their number. A. All the above are true B. None are true C. 1,2,3 are true D. 1,4,5 are true E. 3,4,5 are true F. 1,4 are true.The answer is D.Kennedy class 1 does involve bilateral edentulous areas posterior to the natural teethwhile a Class II has a unilateral edentulous area posterior to the natural teeth. So 1 is true.A Kennedy Class 3 has a unilateral edentulous area with teeth Anterior and Posterior toit. A Class 4 does have a single edentulous area crossing the midline and anterior tonatural teeth. Thus only the second part is true so the answer is false. You can not haveANY mod spaces in a Kennedy Class 4 case. So #3 is false. If a second or third molar ismissing and is not to be replaced it is not considered in Applegates rules. If to bereplaced it will determine the class. Thus #4 is true. Modifications are those areas otherthan those that determine the classification and are designated by their number. Thus #5is true.SOURCE: McCracken’s REMOVABLE PARTIAL DENTURES page 20-21.
11. Which of the following are true concerning resin-bonded bridge designs?1. Contraindications would be mutually protected occlusion (with a canineguidance), more than one pontic, and bruxism.2. A cingulum rest or an occlusal rest is needed to provide a vertical stop.3. A single path of insertion, with parallel grooves.4. 120o of encirclement with a centric occlusal contact only.5. Resistance form, a shallow chamfer at a depth of .25 to .5 mm. a. 1,2,3 are true. b. 3,4,5 are true. c. All are true. d. 2,3,5 are true. e. 1,3,5 are true.The answer is D.Mutually protected occlusion is not a contraindication, the notes state that it is moredesirable than group function, and is only a relative contraindication. A cingulum rest oran occlusal rest is needed to provide a vertical stop, a single path of insertion withparallel grooves is also necessary. 180o of encirclement is needed with a centric occlusalcontact only. And finally resistance form is needed with shallow chamfer at a depth of .25 to .5 mm.SOURCE: CAPT Joe Rusz’s lecture 13 FEB 02
12. After surveying your diagnostic casts you determine your RPD design and the necessary alterations. The design is then drawn on the cast and you are now ready to make tooth modifications. In what sequence will you follow? a. Heights of contour / guiding planes / rest seats / diagnostic impression b. Guiding planes/ diagnostic impression / heights of contour / rest seats c. Guiding planes / heights of contour / rest seats / diagnostic impression d. Guiding planes/ heights of contour / diagnostic impression / rest seatsThe correct sequence for preparing teeth to serve as RPD abutments is D. Guidingplanes/ heights of contour / diagnostic impression / rest seats1.) Proximal surfaces parallel to the path of placement should be prepared to provideguiding planes.2.) Axial tooth contours should be modified lowering the height of contour so that theorigin circumferential clasps may be placed below the occlusal surface; and the retentiveclasp terminus is located below the junction of the middle and gingival third (betteresthetics and mechanical advantage); reciprocal clasps can be placed above HOC at thejunction of the middle and occlusal thirds.3.) Diagnostic/verification impression in irreversible hydrocolloid poured in fast set stoneto re-survey and confirm adequacy of preparations. If further adjustments need to bemade you will not disturb your rest seat preps4.) Occlusal rest seats are always last and should be prepared in a manner that they willdirect occlusal forces along the long axes of the abutment toothMcGivney, G.P., Castleberry, D.J., McCracken’s Removable Partial Prosthodontics 9thEdition, Mosby 1994, pages 281, 287-288.
13. The signs of Ellsworth / Kelly Combination Syndrome are: 1. Papillary hyperplasia 2. Maxillary tuberosity growth 3. Ridge resorption of mandibular posterior 4. Ridge resorption of anterior maxilla 5. Hyper-eruption of mandibular anterior teeth A. 1, 2, 4, 5 B. 2, 4, 5 C. 2, 3, 4, 5 D. All of the aboveCorrect answer is D. All of the aboveThe Glossary of Prosthodontic Terms1 defines combination syndrome as “thecharacteristic features that occur when an edentulous maxilla is opposed by naturalmandibular anterior teeth, including loss of bone from the anterior portion of themaxillary ridge, overgrowth of the tuberosities, papillary hyperplasia of the hard palatalmucosa, extrusion of mandibular anterior teeth, and loss of alveolar bone and ridge heightbeneath the mandibular removable partial denture bases, also called anteriorhyperfunction syndrome.”In addition the following have been added as a subset to the classic signs listed above:loss of vertical dimension of occlusion, occlusal plane discrepancy, anterior spatialrepositioning of the mandible, poor adaptation of the prostheses, epulis fissuratum, andperiodontal changes. However, these changes are not generally associated withcombination syndrome.Palmqvist S, Carlsson GE, Owall B. The combination syndrome: a literature review. JProsthet Dent. 2003 Sep;90(3):270-5.
14. When replacing a missing cuspid with an FPD, occlusion should be shared withthe first bicuspid (i.e. Group function). When replacing a missing cuspid with anFPD, occlusion should remain only on the cuspid (i.e. Canine guidance) a. Both statements are true b. Both statements are false c. First statement is true, second statement is false d. First statement is false, second statement is trueAnswer is C. First statement is true, second statement is falseGroup function, also termed unilaterally balanced articulation, is defined as excursivecontacts that occur distal to the cuspid (can include or exclude the cuspid) on the workingside in laterotrusive movements without contacts on the non-working, mediotrusive side.This can be advantageous if the periodontal support of the cuspid is compromised, ornon-existent in this case. Then the load is distributed and shared by directing it over anocclusal surface that has sufficient periodontal support.Canine guidance of laterotrusive movements of the mandible results in completedisclusion of all posterior teeth. This is expanded to the “scheme” of a MutuallyProtected Occlusion in which the six maxillary anterior teeth together with the sixmandibular anterior teeth guide excursive movements and allow no posterior contacts tooccur during lateral or protrusive movements.Rosenstiel, Land, Fujimoto. Contemporary Fixed Prosthodontics 3rd Edition, Mosby2001, Pages 94-97, 105
15. Post denture insertion pain – everything is sore – Why? 1. Over extended borders 2. Acrylic monomer allergy 2. Excessive vertical dimension of occlusion 3. Insufficient vertical dimension of occlusion 4. Occlusal prematurity A. 1, 2, 3, 4 B. 1, 3, 4, C. 1, 2, 3, 5 D. 1, 3, 5 E. 1, 3, 4, 5Answers: E. 1, 3, 4, 5 Over extended borders, excessive vertical dimension,insufficient vertical dimension, occlusal prematurity.1- Over extended borders can cause: Soreness in the vestibules, sore spots from a deepposterior palatal seal, trouble swallowing, immediate gagging upon swallowing, anddenture instability when out of occlusion.2- Acrylic monomer allergy can cause: Generalized burning sensation.3- Excessive vertical dimension of occlusion can cause: Generalized ridge soreness,immediate gagging, muscle soreness, TMJ symptoms, trouble swallowing, clickingduring speech, and excessive display of teeth.4- Insufficient vertical dimension of occlusion can cause: Angular cheilitis, musclesoreness, TMJ Symptoms, and tongue or cheek biting.5- Occlusal prematurity can cause: Sore spots in the vestibule or on the ridges, delayedgagging upon swallowing, muscle soreness, TMJ symptoms, denture instability when inCR occlusion.Naval Post Graduate Dental School, Complete Denture Syllabus, NDS Course #252,Troubleshooting, Pages 113-116
16. When restoring two edentulous spaces on either side of a pier abutment it isbeneficial to employ a stress breaker. If you intend to restore a missing #7 and #9with a 5 unit FPD abutted on #’s 6, 8, and 10, where would you employ thecomponents of the stress breakera. Key on distal of #9 pontic, keyway on mesial of #10 abutmentb. Key on mesial of #7 pontic, keyway on distal of #8 abutmentc. Key on mesial of #9 pontic, keyway on mesial of #8 abutmentd. Key on distal of #8 abutment, keyway on mesial of #7 pontice. Key on mesial of #8 abutment, keyway on mesial of #9 ponticf. Key on distal of #10 abutment, keyway on mesial of #9 ponticAnswer is B. Key on mesial of #7 pontic, keyway on distal of #8 abutmentA stress breaker, now referred to as a stress director, is a device or system that relievesspecific dental structures of part or all of the occlusal forces and redirects those forces toother bearing structures. These can be utilized in fixed partial dentures of long spans,while spanning multiple edentulous spaces when pier abutments are used, forperiodontally involved teeth.The director is placed on the mesial of the distal pontic, behind the pier abutment. Thekey component of the director is always placed on the pontic so that forces of occlusiondirect it to seat in the keyway component placed on the pier abutment. If the reversewere done occlusal forces would un-seat the components sliding the keyway out of thekey thus making the pontic a lever arm that exerts torque on the abutment to which it isattached.Rosenstiel, Land, Fujimoto. Contemporary Fixed Prosthodontics 3rd Edition, Mosby2001, Page 81Shillingburg, Hobo, Whitsett. Fundamental of Fixed Prosthodontics 2nd Edition,Quintessence Books 1981, Page 414-416
17.In respects to pontic design, order the following according to decreasingesthetics? a. Modified Ridge-lap, Conical, Ovate, Saddle, Sanitary b. Saddle, Modified Ridge-lap, Conical, Sanitary, Ovate c. Modified Ridge-lap, Ovate, Conical, Saddle, Sanitary d. Ovate, Modified Ridge-lap, Saddle, Conical, Sanitary e. Ovate, Modified Ridge-lap, Conical, Saddle, SanitaryThe answer is D. Ovate, Modified Ridge-lap, Saddle, Conical, SanitarySanitary or Hygienic. Recommended Location: posterior mandible. Advantage: goodaccess for oral hygiene. Disadvantage: poor esthetics (2mm clearance between ridge andpontic). Indications: non-esthetic zones, impaired oral hygiene. Contraindications:esthetic zone, minimal VDO.Saddle-ridge-lap. Recommended Location: none. Advantages: esthetics. Disadvantages:not amenable to oral hygiene. Indications: not recommended. Contraindications: all.Conical. Recommended Location: molars without esthetics requirements. Advantages:good access for oral hygiene. Disadvantages: poor esthetics. Indications: posterior areaswhere esthetics is of minimal concern. Contraindications: poor oral hygiene.Modified ridge-lap. Recommended Location: High esthetic requirements. Advantages:good esthetics. Disadvantages: moderately easy to clean. Indications: most areas withesthetic concerns. Contraindications: areas with minimal esthetic concern.Ovate. Recommended Location: Maxillary incisor, cuspids, and bicuspids. Advantages:superior esthetics, negligible food entrapment, ease of cleaning. Disadvantages: requiressurgical preparation. Indications: desire for optimal esthetics, high smile line.Contraindications: unwillingness for surgery, mandibular posterior.Rosenstiel, Land, Fujimoto. Contemporary Fixed Prosthodontics 3rd Edition, Mosby2001, Page 520-525
18. What muscles are involved with border molding for a complete denturemandibular final impression? a. Buccinator, masseter, mylohyoid, palatoglossal, medial pterygoid and the superior constrictor muscle b. Buccinator, masseter, mylohyoid, palatoglossal, and the genioglossus muscle c. Buccinator, masseter, mylohyoid, hyoglossus and the superior constrictor muscle d. Buccinator and masseterThe answer is AThe borders of the final denture impression are determined by several muscles.The buccal vestibule is influenced by the buccinator muscle.The distobuccal border is determined by the actions of the masseter. The massetercontacts forcing the buccinator muscle in and decreases the space available for thedenture. This action can cause it to dislodge.The buccinator, superior constrictor, and the tendon of the temporalis influence theretromolar pad placement of the denture.The posterior lingual border position is controlled by the mylohyoid muscle. Duringswallowing the muscle contracts and raises the floor of the mouth.The superior constrictor, mylohyoid and palatoglossal, and medial pterygoid muscle canall influence the border molding in the retromylohyoid region.The obicularis oris shapes the labial vestibule.The maxillary denture borders are affected by the obicularis ori, buccinator, levatoranguli, and the masseter..Boucher’s Prosthodontic Treatment for Edentulous Patients, Eleventh Edition. Pg166-172
19. The only universally flexible clasp shape is the round form. Half round will flex away form the tooth. a. Both statements are true b. Both statements are false c. Statement one is true and two is false d. Statement two is true and one is falseThe answer is A. Full round clasps are able to flex in any direction. Half round is flexible in only the direction away from the tooth. The type of material the clasp is made form determines flexibility as well. Cast chromium alloys are less flexible than wrought wire. The bulk or thickness of the clasp is a factor. Gold clasps must be thicker to obtain strength so they are not as flexible as a thinner chromium clasp. A retentive arm that is tapered length wise and width wise is more flexible than one that is not. The longer the retentive arm (I-bar) the more flexible it becomes. The least flexible clasp would be a short, no taper, half round, bulky clasp.McCracken’s Removable Partial Prosthodontics, Ninth Edition, 91-93.
20. Centric relation is defined as: a. The position in which the condyle is in the most superior anterior position in the articular fossa with the thinnest portion of the disk between the condyle and the fossa. b. The position in which the condyle is in the most superior retruded position in the articular fossa with the thinnest portion of the disk between the condyle and the fossa. c. The position in which the condyle is in the most superior retruded position in the articular fossa with the thickest portion of the disk between the condyle and the fossa. d. The position in which the condyle is in the most inferior retruded position in the articular fossa with the thickest portion of the disk between the condyle and the fossa.The answer is A. Centric relation is the most physiologic stable and repeatable position of the condyle. This position is helpful in restoring patients that do not have a stable maximum intercuspation or no repeatable jaw relationship. The disk must be situated with the thinnest part between the condyle and the fossa. The Academy of Prosthodontics defines it as the maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective disk with the complex in the anterior-superior position against the shapes of the articular eminence. This position is independent of tooth contact. The mandible is restricted to purely rotary movement about the transverse axis. Management of Temporomandibular disorders and occlusion, Fifth edition. Pg. 111-113. The Academy of Prosthodontics. Glossary of Prosthodontic Terms, Journal of Prosthetic Dentistry;71:1, 1994.
21. Double abutments can be used as a means of overcoming problems created byunfavorable crown to root ratios. Since there are two abutments acting together it isnot necessary for additional abutment to have as much root surface as the firstabutment. a. Both statements are true b. Both statements are false c. Statement one is true and two is false d. Statement two is true and one is falseThe answer is C.Antes law indicates that the surface area of roots in bone of the abutment teeth should beequal to or greater than the teeth they are replacing with a FPD. If inadequate root surfacearea is present it is possible to use double abutments to compensate for this. Thesecondary abutment must have as much root surface area as the primary abutment tooth.The retainer of the secondary abutment tooth must be as retentive as the primaryabutment. There must be sufficient space to allow for soft tissue under the connectorbetween the primary and secondary abutment. Double abutments also help resist the leverarm that can be produced if an FPD spans around the arch; such as a FPD that replacesthe four anterior teeth.Shillingburg, Fundamentals of Fixed Prosthodontics, Third Edition, Page 93
22. Electrosurgery units will work without a grounding plate. Grounding plates areonly necessary if a metal restoration might be contacted. a. Both statements are true b. Both statements are false c. Statement one is true and two is false d. Statement two is true and one is falseThe answer is C.The grounding plate also known as the indifferent plate, neutral electrode, dispersiveelectrode r patient return is necessary for using the unit. Electrosurgery units will workwithout the grounding plate but the patient is at risk of receiving a burn. Propergrounding is the single most important safety issue. It is acceptable to attach the metallicmesh grounding antenna under the upholstery insulated from all metal parts.Fundamentals of Fixed Prosthodontics, Third Edition, 269-271
23. Lingualized occlusion uses anatomic maxillary teeth opposing mandibularmonoplane teeth. Lingualized occlusion can be indicated for skeletal Class II and IIIpatients. a. Both statements are true b. Both statements are false c. Statement one is true and two is false d. Statement two is true and one is falseThe answer is A.Lingualized occlusion is useful for patients that are difficult to reproduce an accurate CRposition. This scheme gives freedom of movement and reduces interferences to protrusivemovements. It is esthetic using maxillary anatomical teeth and is easy to set the teeth anddevelop a cross arch balanced occlusion.1. Becker CM, Swoope CC, Guckes AD. Lingualized occlusion for removableprosthodontics. J Prosthet Dent 1977;38(6):601-8.2. Clough HE, Knodle JM, Leeper SH, Pudwill ML, Taylor DT. A comparisonof lingualized occlusion and monoplane occlusion in complete dentures. JProsthet Dent 1983;50(2):176-9.3. Lang BR, Razzoog ME. Lingualized integration: tooth molds and anocclusal scheme for edentulous implant patients. Implant Dent 1992;1(3):204-11.4. Ohguri T, Kawano F, Ichikawa T, Matsumoto N. Influence of occlusal scheme onthe pressure distribution under a complete denture. Int J Prosthodont 1999;12(4):353-8.
24. Which are advantages of polyether impression materials? a. Fast setting and good for undercuts b. Fast setting, good shelf life (two years), multiple pours c. Very flexible and good for deep undercuts d. Slow setting with prolonged working timeThe answer is B.Polyether is a very stiff material that is not good for undercuts. Undercuts must beblocked out. The material is rigid and dimensional stability is good. Multiple pours canbe done. The shelf life for the material is about two years. It sets fast and has a shortworking time. Finish lines can be easily read. Polyjel, Impregum F, and Permadynes areall examples.Polysulfides have good surface detail, flows into deep subgingival crevices, excellent tearstrength, and multiple pours are possible. Disadvantages are it is not good for severeundercuts, hydrophobic, and it has a bad odor and color.Condensation silicones are an older material that has poor dimensional stability, requiresimmediate pouring, hydrophobic, and produces ethyl alcohol as a by product.Addition silicones are accurate, good for undercuts, and multiple delays pours arepossible. The material is costly, and can release hydrogen gas. Palladium is used as a gasscavenger. Powder from the gloves may inhibit set of the putty.Hydrocolloids are accurate and inexpensive, however they have low tear strength and areaccurate for only one pour.Zinc oxide eugenol will adhere to compound and acrylic, can build borders with it, hardwhen set, good working time, accurate, and dimensionally stable. Disadvantages are thebad taste and rigidity is not good in undercuts.Impression compound has little to no taste, minimal mess, hard when set, and has a goodworking time. It cannot register fine detail and will displace soft tissue.Fundamentals of Fixed Prosthodontics, Second edition. Pages 221-225
25. A patient with complete dentures makes tries to make “T” sounds but he makesa sound like “Th”. What is the most likely cause?a. Anterior palate too broad.b. Inadequate interocclusal distance.c. Poor retention of dentures.d. Overextended maxillary posterior border.e. Maxillary premolars too far mesially.Answer: b) Inadequate interocclusal distance (Also caused by maxillary teeth too far lingual)Solution: Remount, increase interocclusal distance by reducing VDO, or make new CD’s. (Or reset teeth) a) causes sounds like “sh” c) clicking during speech d) causes gagging e) causes whistlingPhonetics and the linguodental and linguopalatal sounds.- Linguodental sounds: “Th”1/3 (3mm) of tip of tongue extends between maxillary and mandibular anterior teeth.If tongue does not protrude past teeth, maxillary anterior teeth are too far labial or there isexcessive overlap.If more than 6mm of tip of tongue protrudes, maxillary teeth are set too far lingually.- Linguopalatal sounds: T & DTip of tongue contacts anterior part of palate or lingual side of anterior teeth.Teeth too far lingual, “T” tends to sound like “D”.Teeth too far labial, “D” sounds like “T”.Denture base palate – too thick in rugae area.Phonetics are related to:- Speaking space.- Denture base, “S” sounds, Rugae area, Lingual extension of mandibular denture.- Tooth positioning, “T” and “D” sounds, “F” and “V” sounds, “S”, “J”, and “Ch”sounds.Reference: Complete Denture Syllabus, Prosthodontic Dept, NPDS, NNDC Bethesda.Rahn, A.O., Heartwell, C.M., Textbook of Complete Dentures, 5th Ed. 1993 Lea &Febiger. Page 330.
26. Which functions are simple hinge articulators not capable of doing? 1. Two dimensional movements 2. Close customization of temporomandibular joint anatomy 3. Reproduction of side shifts 4. Accept facebow transfer a. 1 only b. 1,2,3 c. 2,3,4 d. 1,2,3,4Answer: c) 2,3,4 The hinge articulator can only perform two dimensionalmovements.Articulator Classification: I. Simple hinge II. Non-adjustable III. Semi-adjustable IV. Fully-adjustableFully adjustable articulator (Class IV)Refers to the reproducibility of the patient’s condylar paths.Only instruments that can produce all condylar border movements including protrusive-lateral paths can be called fully adjustable.Accepts facebow transfer.Simple hinge articulators (Class I)Accepts single static record.Barn door hinge.Vertical motion with very limited lateral movement.Smaller arc of closure that does not come close to actual.Simple hinge articulators are limited only to movements a patient cannot make. Dawsonalso writes that they are a major cause of errors in occlusal contouring and have no valuefor restorative procedures or occlusal analysis.Ref: Occlusion, Dawson. Page 206.
27. When using a kinematic facebow one should expect at least a 5mm error inrecording the true hinge axis. The arbitrary facebow records an approximation ofthe true hinge axis by means of average measurements. a. First statement is true, second is false. b. First statement is false, second is true. c. Both statements are true. d. Both statements are false.Answer: b) First statement is false, second is true. Kinematic facebow can determinethe hinge axis to within 1mm. Arbitrary facebow uses average measurements asdetermined by each manufacturer.Facebow allows for:- Providing a method of transferring the location of the condylar axis in the skull to thearticulator and relating the upper cast to the articulator.- To record the spatial position of the maxillary arch relative to the opening and closingaxis.Facebow indications: - Fixed Partial Dentures if posterior vertical stop is included in the FPD. - With Centric Relation record that increases Vertical Dimension of Occlusion. - Full mouth rehabilitation. - When anterior guidance is deficient. - Remount procedures. - When VDO is changed on the articulator.Two types of facebows:Arbitrary and Kinematic.- Arbitrary facebows are less accurate but are adequate for many routine dentalprocedures.- Relies on determination by the manufacturer of the average relationship between thetrue hinge axis and an easily identifiable landmark, usually the external auditory meatus.- Alignment may be achieved through the use of earpieces.- A minimum error of 5mm from the axis can be expected. This error can be worsenedby the use of a thick interocclusal record.- The use of an anterior reference point enables the clinician to duplicate measurementsmade on the articulator at subsequent appointments.- Kinematic facebows are needed when it is critical to reproduce the exact opening andclosing movement of the patient on the articulator.- When the relationship between the maxillae and the axis of rotation has beenreproduced, the mandibular cast can be accurately positioned through the use of aninterocclusal record.- The hinge axis of the mandible can be determined to within 1mm by observing themovement of kinematic facebow styluses positioned immediately lateral to the TMJ inclose proximity to the skin.- The kinematic facebow technique is time-consuming, thus limited to extensiveprosthodontics. Change in vertical dimension of occlusion may be included in this group. Contemporary Fixed Prosthodontics, 2nd Ed. Rosenstiel, S.F., Land, M.F., Fujimoto, J.1995 Mosby
28. What is the main purpose of a cast distal extension posterior metal stop? a. Provides for a more rigid RPD framework. b. Increases overall retention of the RPD to resist displacement. c. Provides a positive apical seat (tissue stop) for the RPD in function. d. Prevents bending of the distal extension framework during acrylic processing.Answer: d) Prevents bending of the distal extension framework during acrylicprocessing.Without a cast stop the minor connector leading to the distal extension framework of anRPD is supported at only one end, the proximal end. The minor connector may bendwhen force is applied during packing and processing of the RPD framework.To prevent bending of the framework, a small area at the free end of the minor connector(or distal extension) should contact the master cast. This portion of the minor connectoris called a cast stop.A cast stop is formed by removing a small square (2x2mm in surface area) from the waxup used to create the refractory cast. It is positioned on the posterior strut of the minorconnector as it crosses the center of the ridge.A thickness of at least 1mm is left between the distal extension struts and the master castto allow for sufficient bulk of acrylic packing during processing. The cast stop helpspreserve this thickness during packing. This thickness of acrylic allows for strength ofmaterial as well as room for adjustments.It is the acrylic denture base that provides for the apical seating of the distal extension,not the cast metal stop.Stewart’s Clinical Removable Partial Prosthodontics 3rd Ed., Phoenix, R.D., Cagna, D.R.,DeFreest, C.F. 2003 Quintessence Page 42
29. What all-ceramic porcelain system is strongest (in terms of flexural strength)? a. Traditional powder slurry ceramics b. Infiltrated ceramics /slip-cast (In-Ceram) c. Heat pressed ceramics (Empress) d. Castable glass ceramics (Dicor) e. Machinable ceramics (Cerec)Answer: b) Infiltrated ceramics (slip-cast)Approximate flexural strength ranges for different ceramic systems (these vary accordingto tooth type position):Porcelain fused to metal 300-500+ MPa (for comparison purposes)Traditional slurry 80-140 MPaInfiltrated (slip cast) 450-600 MPaHeat pressed 140-180 MPaCastable 120 MPaMachinable 120-230 MPaTraditional slurry – uses aluminous porcelain formed over platinum foil matrix.Feldspathic porcelain placed over this core.Infiltrated (slip cast) – aluminous porcelain, infiltrated with glass for strength. Notetchable.Heat pressed – 40-50% leucite reinforced ingot heated and physically pressed into lostwax mold. Etchable. Feldspathic porcelain can be placed over this core.Castable – polycrystalline glass ceramic. Processed like lost wax process.Machinable – computer aided design and machining (CAD-CAM). Uses blocks offeldspathic or glass based ceramic and milled to fit the prepared tooth.Adept Report Vol 5 No. 1 Summer 1995 Page 7.Restorative Dental Materials, 11th Ed. Craig, R.G., Powers, J.M. 2002 Mosby Page 567
30. Which are advantages of screw retained implant prosthesis? 1. Corrections can easily be made for angular discrepancies between implant fixture and restoration. 2. Can be more easily retrieved. 3. Easy to obtain path of draw in multiple unit fixed partial dentures. 4. Requires less total vertical space for restoration. a. 1,2 b. 1,3 c. 2,4 d. all of the aboveAnswer : c) 2,4Cement retainedAdvantages:Simplicity and economy are plus. Angle corrections can be made to compensate fordiscrepancies between the implant inclination and the facial crown contour. Abutmentcan include an anti-rotational feature. Best for small tooth replacement. May be moreesthetically pleasing and less expensive.Disadvantages:Require more chair time, same propensity to loosen as screw retained. If zinc phosphate,glass ionomer, or composite resin cements are used, retrieval may be very difficult.Requires more vertical space due to two part construction (Estheticone needs 6.7mmvertical space. Multi unit abutment needs 4.3mm).Screw retainedAdvantages:Retrievability. Crown can be more easily removed for repair, soft tissue evaluation,calculus debridement, and modifications to crown. Forces are usually directed downlong axis of implant, optimum esthetics more easily achieved. Less vertical spacerequired for restoration.Disadvantages:Primary disadvantage is that screw may loosen in function. Screw is tightened to seatimplant crown to a clamping or preload force. Screw will loosen if masticatory force isgreater than the clamping force. Proximal contacts need to be checked carefully soabutment is seated properly (cement abutment does not have this problem). Access holethrough occlusal table of posterior teeth may affect esthetics.Contemporary Fixed Prosthodontics, 3rd Ed., Rosenstiel, Land, Fujimoto, 2001 Mosby.Page 344
31. The quality of a preparation that prevents the restoration from being dislodgedby the forces parallel to the path of the withdrawal is known as retention.The resistance form of tooth preparation resists the lateral and oblique forces whichtend to displace the restoration by causing rotation around the gingival margin. a. Both statements are true. b. Both statements are false. c. The first statement is true, second statement is false. d. The first statement is false, second statement is true.Answer: A° Adequate retention and resistance depends on the following: o Magnitude and direction of the dislodging forces o Type of preparation o Geometry of the tooth preparation Cylindrical to restrain the movement Near parallel preparation. Increased surface area (axial wall height) Adding grooves or boxes to limit the path of withdrawal and to interfere with the rotational movement o Surface roughness o Material being cemented o Type of luting agentContemporary Fixed Prothodontics, Rosenstiel, Land & Fujimoto, 3rd Ed, 2001, p:151-158
32. A slot is a retention groove whose length is in a horizontal plane and in dentinand a lock is a retention groove whose length is in a vertical plane and in dentin.Gingival slots are placed in 0.5 mm pulpal of the DEJ, and at least 0.5 mm in depthand 1 or more mm in length depending on the distance between vertical walls. a. Both statements are true. b. Both statements are false. c. The first statement is true, second statement is false. d. The first statement is false, second statement is true.Answer: A ° Slot and lock retentions may be used in conjunction with pins or as an alternative to it. Lock retentions are used more in preparations with vertical walls which allow locks to oppose one another. ° Pin retention is used more in preparations with few or no vertical walls. Pins are to retain the amalgam not to increase the strength of the restorative material. ° Shorter slots provide as much resistance to horizontal forces do longer slots. ° Slots in the gingival floor may be used to provide additional retention in an extensive proximal box that has facial and lingual walls extending beyond the proximal line angles. ° Slot dimension will depend on the size of the proximal box.REF: Sturdevant’s Art and Science of Operative dentistry 4th Edition; p-503
33. Deflection of an FPD is proportional to the cube of its length. If the force on onepontic produced certain amount of deflection, the same force on a three pontics willproduce eight times the distance of the deflection. a. True b. FalseAnswer: B ° According to Law of beams, for 2 Pontics= 8 times the distance, for 3 pontics= 27 times the distance. ° Edentulous span length will influence the prep design, number of abutments and the design of FPD connectors. ° Excessive flexing under occlusal loads may cause failure of a long-span FPD. It can lead to fracture of porcelain, breakage of a connector, loosening of a retainer, and unfavorable soft tissue response. All FPDs flex slightly under load, the longer the span, the greater the flexing. ° When a long-span FPD is fabricated, pontics and connectors should be made as bulky as possible to ensure maximum rigidity without compromise the gingival health. Also, the FPD material should have high strength and rigidity.NPDS Fixed Prosthodontics Syllabus 2002.Contemporary Fixed Prothodontics,Rosenstiel, Land & Fujimoto, 3rd Ed, 2001, p: 72-73.
34. Stress-bearing areas are recorded with least amount of pressure and selectivepressure is applied to the non-stress-bearing areas.The places with less space or relief will transmit more pressure during theimpression. a. Both statements are true. b. Both statements are false. c. The first statement is true, second statement is false. d. The first statement is false, second statement is true.Answer: D ° Selective pressure technique combines the principles of both pressure and non- pressure procedures. Non-stress-bearing areas are recorded with least amount of pressure and selective pressure is applied to the stress-bearing areas that are capable of withstand the forces of occlusion. ° The impressions are made in trays that have been selectively relieved, therefore providing more space in some areas while at the same time having areas within the trays that have less space. The places that have less space or relief will transmit more pressure during the impression. This will distribute the greater force during function to a more favorable part of the area. ° Clinical evidence seems to favor the selective pressure technique over functional/ physiologic or mucostatic technique.REF: Complete Denture Syllabus, NDS Course#252.
35. What impression material is most stable 24 hours later? a. Polysulfides b. Polyethers c. Addition silicones d. Condensation siliconesAnswer: C° Dimensional change: Condensation silicones> Polysulfides>Polyethers> Addition silicones° Addition silicones advantages include: accurate, good for undercut, multiple pours and delay pours. Disadvantages include: costly, some hydrophobic, powder from gloves can inhibit set of putty. Secondary reaction may produce hydrogen gas, and some brands contain Palladium as hydrogen scavenger. Not all addition silicones release hydrogen gas, it is recommended that to wait 30 minutes for the setting reaction to be complete before pouring. Material Consistency Dimensional change at 24 hr (% ) Polysulfides Low -0.40 Med -0.45 High -0.44 Polyethers Low -0.23 Med -0.24 High -0.19 Addition silicones Low -0.15 Med -0.17 High -0.15 Very High -0.14 Condensation silicones Low -0.60 Very High -0.38NPDS Fixed Prosthodontics Syllabus 2002Restorative Dental Materials, Craig and Powers, 11th ed. 2002. p: 359
36. Which of the following statement regarding AP Rotational path RPD design arecorrect? 1) In Rotational path, one portion of the RPD is placed first, while with a conventional path of placement all rests are seated more or less simultaneously. 2) Adjustment of the rigid retentive component is necessary. 3) Minimizes number of clasps. 4) Tolerates error well. 5) May be used as substitute to a long-span anterior FPD. 6) Used in absence of lingual or facial undercuts in anterior abutment teeth in Kennedy class IV anterior abutment teeth. a. 3, 4, 5, 6 b. 1, 2, 3, 5 c. 2, 3, 5, 6 d. 1, 3, 5, 6 e. 1, 2, 3, 6Answer: D ° The rotational path concept cannot be reduced simply to a straight path that deviated marked from the perpendicular. While still fulfilling the requirements of support, stability and retention, proper use of the rotational path permits elimination of clasps. Therefore minimized number of clasp, reduced plaque accumulation and improved aesthetic. ° The rigid retentive components are placed or rotated into undercuts and are maintained in intimate tooth contact by their modified rests and other conventional clasp in the design. Adjustment of the rigid retentive component is difficult and little tolerance for error. Distortion of rigid retentive component is unlikely. Rigid retainer may prevent further tipping of abutment teeth contacted. ° The retentive undercuts are located in mesial and distal interproximal undercuts (0.20”) therefore often used in absence of lingual or facial undercuts.Rotational path of placement for tooth borne partial dentures, Graziani. Handout, 2002.Removal Partial Denture Design Outline Syllabus, Krol, Jacobson, Finzen, 4th ed, 1990,p: 69-88
37. Researchers have reported that there is little association between the choice ofzinc phosphate or glass ionomer cements and increased pulpal sensitivity whenmanufacturers’ recommendations were followed. a. True b. FalseAnswer: A° If post-cementation sensitivity is a concern, the dentist should evaluate their technique, especially to avoid desiccation of the prepared dentin surface.° Use ZOE with EBA, Zinc polycarboxylate or resin modified glass ionomer, which have been reported to exhibit less post-cementation sensitivity.° Avoid zinc phosphate, which cavity varnish may be necessary to decrease pulp irritation.Contemporary Fixed Prothodontics, Rosenstiel, Land & Fujimoto, 3rd Ed, 2001, p:766-71.Restorative Dental Materials, Craig38. Which of the following are true regarding die spacers?
1. No relief space is necessary when pouring dies with Type IV stone with gypsum hardener due to the percentage of dimensional change caused by hygroscopic expansion. 2. The most common die spacers are epoxy die resin. 3. One may substitute proprietary paint-on liquids, such as model paint, colored nail polish, or thermoplastic polymers dissolved in volatile solvents. 4. Die spacers are placed to within 1.0 mm of the preparation finish line to provide relief for the luting agent. a. 1, 2, 3 b. 2, 3, 4 c. 1, 3, 4 d. 3, 4The correct answer is d. (3 and 4) 1. Is false. To produce relief space for cement, it is common to use a die spacer with a stone die. 2. Is false. Epoxy die materials are used for fabrication of the die, not as a spacer material. They are reliable with respect to dimensional change, but are slightly undersized. 3. Is true. One may substitute proprietary pain-on liquids, such as model paint, colored nail polish, or thermoplastic polymers dissolved in volatile solvents. 4. Is true. Die spacers are placed to within 1.0 mm of the preparation finish line to provide relief for the luting agent and to ensure complete searing of an otherwise precisely fitting casting.References: Anusavice K: Philips’ Science of Dental Materials, 10th Ed. WB Saunders,1996.
39. Which of the following statements regarding the film thickness of dental lutingcements includes are true? 1. ADA Specification No. 8 Type I states that film thickness be 100 um (maximum). 2. Zinc phosphate is generally the thickest of the luting agents 3. Polycarboxylate cement has one of the highest compressive strengths, but, does not meet the maximum thickness guidelines. 4. Polycarboxylate cements yields a film thickness of 25 um or less due to the action of spatulation and seating with a vibratory action to reduce the viscosity. 5. Glass ionomer luting cements are a type I cement with a particle size of 15 um or less. a. 3 only b. 1 and 3 c. 1 and 2 d. 1, 2, 3 e. 4 and 5The correct answer is e. (4 and 5) 1. is false. ADA Specification No. 8 Type I states that film thickness be 25 um (maximum). 2. is false. Zinc phosphate is generally the thinnest of the luting agents, with a thickness of 20 um. 3. is false. Polycarboxylate cement has one of the lowest compressive strengths, but, does meet the maximum thickness guidelines with a thickness rivaling zinc phosphate (21um). 4. is true. Polycarboxylate cements appear to be much more viscous than is a comparable mix of zinc phosphate cement. As the mix is classified as pseudoplastic, it undergoes thinning at an increased shear rate. Clinically, the cement yields a film thickness of 25 um or less due to the action of spatulation and seating with a vibratory action to reduce the viscosity. 5. is true. Don’t’ confuse particle size with film thickness. GIC film thickness is more viscous than Zinc phosphate polycarboxylate cements; it has a minimum thickness of approximately 24 um.It is important to know the thickness of various cements. Note the following:Cement type Setting Film 24 hour 24 hour Elastic Solubility Pulp time thickness compressive tensile modulus in water response (min) (um) strength strength (Gpa) (Wt%) (Mpa) (Mpa)ANSI/ADA 5.0 25 max. 69 na na 0.2 max *see notespecification 8 (Type I) min.Zinc phosphate 5.5 20 104 5.5 13.5 0.06 ModerateZOE (TYPE I) 4-10 25 6-28 __ __ 0.04 Mild
40. Regarding denture impressions, which of the following are true?1. Definite pressure was advocated by many dentists as the best means for obtainingan ideal impression as it logically applied the same pressure as was being appliedduring chewing.2. The mucostatic technique embodies the idea that the interfacial surface tensionwas the best way to retain dentures3. The selective pressure concept embodies the principles of both pressure andmucostatic (nonpressure) procedures.4. In selective pressure technique, the non-stress bearing areas are recorded with theleast amount of pressure in certain areas of the maxillae and mandible that arecapable of withstanding the forces of occlusion.5. Low-fusing Impression waxes are not sufficiently accurate for a final impression. a. 1 and 3 b. 1, 3, 4 c. 1, 2, 3, 4 d. 2 and 4 e. All of the above.The correct answer is e. All of the above.1. Is true. Definite pressure was advocated by many dentists, as it presumed that theocclusal loading during the impression would be the same as occlusal loading duringfunction.2. Is true. The mucostatic or nonpressure technique embodies the idea that the interfacialsurface tension was the best way to retain dentures. Despite many advocates, it becameknown that the non-pressure technique could only be obtained by sacrificing theimportant concepts of maximum ridge coverage and border seal.3. Is true. The selective pressure concept embodies the principles of both pressure andnonpressure procedures.4. Is true. In selective pressure technique, the non-stress bearing areas are recorded withthe least amount of pressure, and selective pressure is applied to certain areas of themaxillae and mandible that are capable of withstanding the forces of occlusion. Theseimpression area made in trays that have been selectively relieved, therefore providingmore space in some areas while at the same time having areas within the tray that haveless space. The places that have less space or relief will transit more pressure during theimpression. Ideally, this will then distribute a greater force during function to a morefavorable part of the ridge/bone (such as the buccal shelf) and less pressure tounfavorable parts (such as sharp ridge crests or bony spicules). Clinical evidence favorsthe selective pressure technique.5. Is true. Low-fusing Impression waxes are not sufficiently accurate for a finalimpression for complete dentures, but, are satisfactory as a corrective material for a smallarea and for border refining for a tray. Iowa wax or Type I ZnOE can both be used tocorrect minor defects.References: Complete Denture Syllabus, NPDS, Bethesda Rahn AL and Heartwell CM: Textbook of Complete Dentures, 5th Ed., Lea and Febiger, 1993.
41. Which one of the following is true regarding components of a removable partialdenture? a. Major connectors should be flexible so that functional chewing forces are properly transmitted to the teeth and other tissues. b. A minor connector is the unit of the partial denture that connects the parts of the prosthesis located on one side of the arch with those on the other side. c. The linguoplate can in itself serve as an indirect retainer. d. Each direct retainer and each occlusal rest are joined to the major connector by a minor connector.CORRECT ANSWER: D. is truea. is false. Rigidity of the major connector resists flexing and torque that would beotherwise be transmitted to abutment teeth or other structures as destructive forces.b. is false. A major connector is the unit of the partial denture that connects the parts ofthe prosthesis located on one side of the arch with those on the other side. It is the unit ofthe RPD which other all other parts are directly or indirectly attached.c. is false. The linguoplate should be something that is added to, and not something thatreplaces the conventional lingual bar. The linguoplate and the continuous bar retainershould ideally have a terminal rest at each end regardless of the need for indirectretention.Indications for a linguoplate are: 1. when the lingual frenum is high or the space available for a lingual bar is limited. 2. in class I situations in which the residual ridges have undergone excessive vertical resorption. 3. for stabilizing periodontally weakened teeth. 4. when the future replacement of one or more incisor teeth will be facilitated by the addition of retention loops to an existing linguoplate.There are six types of mandibular major connectors. These include: lingual bar,sublingual bar, lingual bar with cingulum bar (continuous bar) retainer, cingulum bar,Linguoplate and labial bar.There are four basic types of maxillary major connectors. These include: single palatalbar, single palatal strap (U-shaped palatal connector), anterior-posterior palatal bars,combination anterior and posterior palatal strap-type connector.Components of a typical removable partial denture include major connector, minorconnectors, rests, direct retainers, stabilizing or reciprocal components (these serve asparts of a direct retainer assembly), indirect retainers (if the prosthesis has one of moredistal extension bases), and one or more bases (each one supports one or more teeth).Minor connectors arise from the major connector, and unites the major connector withother parts of the denture.The minor connector may be continuous with some other part of the denture. An occlusalrest at one end of a linguoplate is actually the terminus of a minor connector, eventhought that minor connector is continuous with the linguoplate.Also, the portion of a denture base frame that supports the clasp and the occlusal rest is aminor connector, joining the major connector with the clasp.
The portions of the framework by which the denture bases are attached are minorconnectors. The minor connector serves two purposes, which are diametric in function.The first is to transfer functional stress to the abutment teeth.Occlusal forces applied to the artificial teeth are transmitted through the base to theunderlying ridge tissues if that base if primarily tissue supported.Occlusal forces applied to the artificial teeth are also applied to the abutment teeththrough occlusal rests.This is called prosthesis-to-abutment function of the minor connector.The second is to transfer the effect of the retainers, rests, and stabilizing components tothe rest of the denture. This is abutment-to-prosthesis function of the minor connector.References:McGinvney and Castleberry: Mc Cracken’s Removable Partial Prosthodontics, 9th Ed.,Mosby 1995.
42. Which of the following factors concerning retention and resistance for singleunit crowns are false? a. Over tapering of the opposing axial walls can be corrected if a band of several millimeters of tooth structure can be prepared circumferentially with a restricted taper of approximately 6 degrees. b. As taper increases, the free movement of the restoration will do so likewise, and reduce the retention. c. Molar crowns are more retentive than premolar crowns of similar taper. d. Typical placement for grooves in a single unit are mesial and distal. e. A 7/8 crown with grooves has more retention than a complete crown with no grooves. E is the correct answer. It is false statement a. Is a true statement. Over tapering of the opposing axial walls can be corrected if a band of several millimeters of tooth structure can be prepared circumferentially with a restricted taper of approximately 6 degrees. It is probably unnecessary to further modify the preparation to compensate for the areas of excessive reduction in the occlusal third. If this is not the case, one can used an approach slightly less conservative of tooth structure such as uprighting overtapered axial walls to obtain the mechanical advantage of increased retention or using grooves, boxes, or pinholes as needed. b. Is a true statement. Theoretically, maximum retention is obtained if a tooth preparation has parallel walls, but, a slight convergence, or taper, is necessary in the completed preparation. As long as this taper is small, the movement of the cemented restoration will be effectively retained by the preparation and will have what is known as a limited path of withdrawal. As taper increases, the free movement of the restoration will do so likewise, and reduce the retention. c. Is a true statement. Crowns with long axial walls are more retentive than those with short axial walls. Molar crowns are more retentive than premolar crowns of similar taper. Additional information: The factors influencing the resistance of cemented restorations include luting agents of the following in order of decreasing resistance: adhesive resin, glass ionomer, zinc phosphate, polycarboxylate, zinc oxide-eugenol d. Is a true statement. In a short or excessively tapered complete crown, resistance form is minimal because most of the buccal wall is missing. A mesiodistal groove should be placed to increase resistance form. A 7/8 crown with grooves has less retention than a complete crown with no grooves. According to a study by Potts RG et al: J Pros Dent 43:303, 1980. The removal force for a complete crown with no grooves was 1080 N versus the 7/8 crown with grooves which required only 507 N of removal force.References: Rosenthiel, Land and Fujimoto: Contemporary Fixed Prosthodontics, ThirdEd., Mosby, 2001.Potts RG et al: J Pros Dent 43:303, 1980.
43. Which of the following are incorrect for gypsum products? 1. The smaller the water: powder ratio of the original investment water mixture, the less the hygroscopic setting expansion. 2. As the mixing time is reduced, the hygroscopic expansion is decreased. 3. The greatest amount of hygroscopic setting expansion is observed if the immersion takes place after the initial set. 4. The longer the immersion of the investment in the water bath is delayed beyond the time of the initial set of the investment; the lower is the hygroscopic expansion. 5. A mixture of silica and gypsum hemihydrate results in setting expansion greater than that of the gypsum product when it is used alone. a. 1 only b. 1 and 2 c. 1 and 3 d. 3 and 4 e. 5 onlyThe correct answer is c. 1 and 3. 1. Is false. The smaller the water: powder ratio of the original investment water mixture, the greater the hygroscopic setting expansion. 2. Is true. In general, the less the W:P ratio and the longer the mixing time within practical limits, the greater is the setting expansion. 3. Is false. The greatest amount of hygroscopic setting expansion is observed if the immersion takes place before the initial set. 4. Is true. The longer the immersion of the investment in the water bath is delayed beyond the time of the initial set of the investment, the lower is the hygroscopic expansion. 5. Is true.References:Anusavice K: Philips’ Science of Dental Materials, 10th Ed., WB Saunders, 1996.
PERIO1). Which of the following statements concerning the classification of periodontaldisease and conditions are true: 1. Gingival diseases are classified into either dental plaque induced or non- plaque induced. 2. The plaque-induced diseases can be modified by systemic factors, medications and malnutrition. 3. Periodontic-Endodontic lesions are not in the new classification system. 4. Characteristics common to all gingival diseases include non-reversibility of the disease by removing the etiology and precursor to attachment loss around teeth. 5. Non-plaque induced disease may be affected by specific microorganisms, genetic origin, systemic diseases, and traumatic lesions. a) 1, 2, 3, 4, 5 b) 1, 2, 4, 5 c) 2, 3, 4, 5 d) 1, 2, 4, 5 e) 1, 2, 5Answer is e. 1, 2 & 5 are correct. Previous classification (1989) did not include asection on gingival diseases. In this classification, gingival diseases are classified intoeither dental plaque induced or non-plaque induced. Non-plaque induced includes a widerange of disorder that effect the gingiva.3 is false: Periodontic-Endodontic lesions are an additional category in the newclassification system.4 is false: Characteristics common to all gingival diseases include reversibility of thedisease by removing the etiology and precursor to attachment loss around teeth.REF: Armitage, G.: Development of a Classification System for Periodontal diseases andConditions. Ann Periodontal 4: 1-6, 1999
2). What perio procedures are SBE prophylaxis required for? 1. Periodontal procedures including surgery, scaling and root planning, probing and recall maintenance. 2. Dental implant placement. 3. Sub gingival placement of antibiotic fibers or strips. 4. Prophylactic cleaning of teeth or implants where bleeding is anticipated. a) 1 b) 1, 2 c) 1, 2, 3 d) 1, 2, 3, 4Answer: d. All perio procedures require SBE prophylaxis except when bleeding is notanticipated, or suture removal.REF: Dajani AS, Taubert KA, Wilson W, et al “Preventation of bacterial Endocarditis.Recommendations by the AHA,” JAMA, 1997, 277(22): 1794-801
3). If the color band of the PSR probe completely disappears in the periodontalpocket: a) Indicates that PD is less than 5.5mm. b) PSR Code for this sextant is 3. c) Comprehensive periodontal examination and charting of the effected sextant to determine the necessary treatment plan. d) Comprehensive full mouth periodontal examination, charting and treatment planning are needed.The color band of the PSR probe is 3.5 to 5.5 mm. If the color band of the PSR probecompletely disappears in the periodontal pocket indicates that PD is more than 5.5mm.PSR Code for this sextant is 4.Comprehensive periodontal examination and charting of the effected sextant to determinethe necessary treatment plan is indicated for code 3 (color band of the PSR probe ispartially submerged).The correct answer is (d): Comprehensive full mouth periodontal examination, chartingand treatment planning are needed for code 4 patient and two or more quadrant with code3 patient.REF: Carranza, Newman: Clinical Periodontology, 8th Edition. Saunders. Pp: 360-1.
4). PSR (Periodontal Screening and Recording System) is recorded by which of thefollowing? 1. Code 0 indicates there is no bleeding, no calculus, no defective margins, and the colored band remains completely visible. Gingival tissue is healthy and only preventive care is required. 2. Code 1 indicates the color band is completely visible with minor bleeding detected but no calculus is present and there are no defective margins. Subgingval plaque removal and oral hygiene instructions are indicated. 3. Code 2 the color band is partially submerged with bleeding, supra or sub gingival calculus and/or defective margins are present. Treatment includes the removal of plaque and calculus, defective margins, and oral hygiene instructions. 4. Code 3 The colored band is partially submerged. This indicates that the sextant needs a comprehensive periodontal evaluation. If two or more sextants are code 3 than a complete comprehensive evaluation and charting is necessary. 5. Code 4 The colored band is completely covered indicating a depth greater that 6.5 mm. Full mouth charting and treatment planning are required. a) All of the above are accurate statements. b) 1, 2, 3, and 4. c) 1, 2, and 4. d) 1 and 5The correct answer is c.The PSR system uses especially designed probe that has a 0.5 mm ball tip and is coloredcoded from 3.5 to 5.5 mm. The patient’s mouth is divided into six sextants. At least sixareas are examined around each tooth. The deepest finding in each sextant is recorded.Code 2 is incorrect only because the colored band is still fully visible.Code 4 is not correct since the colored band indicates a depth greater than 5.5 mm.Code * : An * after a number indicates that there is one of the following conditions:furcation involvement, tooth mobility, mucogingival problem, or gingival recessionextending to the colored band (3.5 mm or greater).Clinical Peridontology. Eight Edition. Pages 360-361
5). Which of the following pairs are incorrect? 1. Actisite contains tetracycline 2. Periostat conatins doxycycline 3. Periochip contains minocycline HCl 4. Arsestin contains chlorohexidine 5. Atridox is a doxycycline gel. a. 2,3,5 b. 3,4 c. 2,3,4 d. 1,4 Answer: (b). Statement 1 is true. Actisite is a 23cm monofilament of ethylene vinyl acetate impregnated with 12.7mg (0.5mg/cm) of tetracycline. When placed in the pocket for ten days it reaches 100 times the peak levels achieved with systemic oral administration. Indications are sites that fail to respond to conventional therapy. Statement 2 is true. It is a prescription capsule used in conjunction with scaling and root planning. It is a unique form of doxycycline (20 mg caps). It uses the collagenalytic (collagenase inhibitors) properties of tetracycline while limiting bacterial resistance. Statement 3 is not accurate. The Periochip is a 4X5 mm firm gelatin strip impregnated with chlorhexadine. It is inserted into pockets 5mm or greater. It is used as a supplement to scaling and root planning. Statement 4 is not accurate. Arestin contains minocycline HCL (1mg). Microspheres containing the drug are inserted into the pocket. It is used as an adjunct to scaling and root planning. The microspheres are a polymer material that is bioadhesive, bioresorbable. Once inserted it adheres to the periodontal pocket. The drug is slowly released by diffusion form the spheres to the pocket. Arestin maintains therapeutic drug levels for at least 14 days. Statement 5 is correct. It is a gel that solidifies in the pocket and releases tetracycline over a seven day period Information from a lecture by LT Micheal Cabassa, The Role of Pharmacotherapeutics in Periodontal Therapy, October 2002, Naval Postgraduate Dental School
6). Which of the following statements are correct? 1 Supra gingival plaques contain mainly coccoid and filamentous forms of bacteria. 2 “Corncob” which is filamentous forms of bacteria covered with coccal organisms are present in supragingival plaque. 3 Bacterial cells are densely packed the tooth surface in supragingival plaque 4 Subgingival plaque is less organized than supragingival plaque. 5 Numerous spirochetes, gram negative bacteria, and bacteria grouped in “bottle brush” formations are present in subgingival plaque. a) 1,2, and 3 b) 1,2,3, and 4 c) 1 and 3 d) All of the above All of the above are correct. Supragingival plaque is densely packed on the tooth surface about 0.5mm thick or more. Flagellated forms and spirochetes are observed apically and on the outer surface of the supragingival plaque. Subgingival plaque has an outer and inner layer. The inner layer is tightly adherent but is thinner than and not as organized as supraginigal plaque. The outer layer adjacent to the soft tissue is loosely adherent layer. It is composed of the organisms in answer 5. Formation of the dental pellicle is the initial stage of plaque formation. All surfaces of the oral cavity are covered with a glycoprotein. The mechanisms of pellicle formation are electrostatic, Van der Waals forces and hydrophobic forces. Within a few hours bacteria is found on the dental pellicle. The initial bacteria are gram-positive facultative bacteria such as Actinomyces viscosus and Streptococcus sanguis. The initial bacteria adhere to the pellicle by adhesions and fimbriae on the surface of the bacteria. As the plaque matures the bacteria become more gram-negative anaerobic organisms. Secondary colonization of bacteria that do not initially colonize clean tooth surfaces occurs. Coaggreagation is the term to describe different species of bacteria adhering to one another in mature plaque. The Periodontic Syllabus, Third Edtion. Page 15 Clinical Periodontology, 8th Edition Page 86-88
7). Which feature is not found in the implant – soft tissue interface? a) Sulcular epithelium b) Hemidesmosomes c) Sharpey’s fibers d) Basal Lamina e) Glycoprotein insertionAnswer: (c)No Sharpey’s fibers attachment to implant abutment.How do fibers form at implant interface?Architecture:- Peri-implant free gingiva corresponds to teeth.- Sulcular epithelium forms peri-implant gingival crevice.- Implant junctional epithelium.- Basal cell layer with hemidesmosomal attachment to the abutment.- Hemidesmosomes have lamina densa (at abutment surface) and lamina lucida.- Surface oxide layer and hemidesmosomal glycoprotein may form a chemical bondattachment.- Not chemically strong, separated with 20-25 grams of pulling force.- Deep within the sulcus, collagen fibers form a tight cuff around the abutment. Some ofthese fibers run perpendicular to the abutment, others circumferentially. Thus maturecollagen “seal” at the bone level may provide contact inhibition to prevent epithelialdown growth.Ref: Bauman G, Rapley J, Hallmon W, Mills M. The Peri-Implant Sulcus. Int J OralMaxillofacial Implants 1993;8:273-280.
8). What is the order of expected prognosis for treated furcation involved molarteeth from worst to best? a) Mn 1st, Mn 2nd, Max 1st, Max 2nd b) Max 2nd, Max 1st, Mn 2nd, Mn 1st c) Max 1st, Mn 2nd, Max 2nd, Mn 1st d) None of the aboveAnswer: (b) Max 2nd, Max 1st, Mn 2nd, Mn 1stMaxillary molars have worse prognosis than mandibular. Second molars have worseprognosis than first molars.Glickman I – feel fluting, not roofGlickman II – engage roofGlickman III – Probe goes through furcationGlickman IV – Can see through furcationFurcation treatment options:- Non surgical- Regenerative- Resective- ExtractionUnder regenerative option:- Flap curettage- Osseous grafts- Guided tissue regeneration for I and IIMax 2,3rd molars lost most frequently.Maxillary premolars with furcation involvement have a poor to hopeless prognosis.The diagnosis and treatment of molar furcation invasions. Newell, D.H., Dental Clinicsof North America Vol 42 (2) 1998A long-term survey of tooth loss in 600 treated periodontal patients. Hirschfeld, L. andWasserman, B. J Perio 49: 225, 1978
9.WHAT MAKES A PERSON SUSCEPTIBLE (IMMUNOLOGICALLY) TORAPIDLY PROGRESSING PERIODONTAL DISEASE?Rapidly Progressing Periodontal Disease is characterized by which of the following? 1. progresses 3-4 times faster than adult periodontitis 2. affects lower incisors and first molars with vertical osseous defects 3. bone loss is inconsistent with the amount of local factors present 4. a gram negative obligate anaerobic cocci is considered a primary etiologic microorganism a. 1,2,4 b. 2,3,4 c. 1,2,3 d. 1,3,4 e. all of the above The correct answer is C- 1,2 3 are trueDefinition of RPP: a disease of the periodontium that occurs in an otherwise healthyadolescent, characterized by rapid loss of alveolar bone, lack of severe clinical signs ofinflammation, and sparse plaque accumulation. Destruction is not commensurate withlocal factors.Characteristics of RPP: Onset around puberty (11-15 years of age) Isolated areas of attachment loss and bone loss (greater at permanent incisors and 1st molars) Evidence of local, specific bacterial causes Actinobacillus actinomycetemcomitans, Capnocytophaga Rod gram - negative obligate anaerobe, found at the base of pocket Neutrophil dysfunction is a common feature Familial distribution of the disease, and there is no identified systemic disease.PF Fedi et al The Periodontic Syllabus, 4th Ed pp 34-35.
10). Several factors predispose diabetics to periodontitis. Which are correct? 1. elevated glucose levels in oral fluids can influence microbial flora 2. impaired erythrocyte function, including phagocytosis may reduce resistance to periodontitis 3. altered collagen metabolites and vascular changes including stasis 4. impaired chemotactic and phagocytic activity of polymorphonuclear leukocytes a. 1,2,3 b. 1,3,4 c. 2,3,4 d. 3,4 e. all the above Answer: (b) The glucose content of gingival fluid and blood was found to be higher in diabetics. Thickening of the basement membrane of capillaries may hamper the transport of nutrients. The increased susceptibility of diabetics to infection has been hypothesized as being due to PMN deficiencies resulting in impaired chemotaxis, defective phagocytosis, or impaired adherence. Glickman’s Clinical Periodontogy 6th ed. pp. 464-465
11). All of the following have shown some clinical correlation with periodontitisexcept: a. Cardiovascular disease b. Stroke c. Pernicious anemia d. Low birth weight babies e. Respiratory disease. Answer: (c). Ample evidence has shown a relationship of periodontal health as an important component in management of some systemic diseases. A relationship is suggested between acute systemic infections and the occurrence of cardiovascular disease that includes myocardial infarction and stroke. Low birth weight babies- believed to occur because accumulation of gram(-) micro organisms such as those found in periodontitis results in increased release of prostaglandin and cytokines which may act on distant sites such as the placenta. Severe Periodontitis is associated with upper and lower respiratory disease such as hospital acquired pneumonia. REFERENCE: Fedi Perio Syllabus 4th edition 2000 pg.29 and 90.
12). Concerning grafts which of the following are TRUE. 1. Osteoinductive is where the graft acts as a template for bone formation. 2. Osteogenesis is where the graft stimulates new bone formation. 3. Small particle size of 300 to 500 microns is advantageous. 4. Osteoconductive is where the cells of the graft actually produce new bone. 5. Cortical bone is the best source of pluripotential osteogenic cells. 5. Adequate vascularity is needed (intramarrow penetration with a ½ round bur). 6. A mechanically stable wound site-primary flap closure and circumferential seal is necessary. 8. Emdogain is enamel matrix proteins obtained from pigs. a) all are true b) 1,3,6,7 are true c) 1,2,3,4 are true d) 3,6,7,8 are true e) 4,5,6,8 are trueA. Answer: (d) OSTEOCONDUCTIVE- the graft acts as a template or trellis to assist in bone formation and deposition. OSTEOINDUCTIVE- The graft acts to stimulate or induce new bone formation by undifferentiated cells. OSTEOGENESIS- The cells of the graft actually produce new bone. The smaller size of particles are easier for the body to resorb and more actively induce regeneration in osseous defects. Cancellous bone is the best source of pluripotential osteogenic cells. Adequate vascularity is needed and intramarrow penetration with a ½ round bur can be used to aid in a bleeding bed. A mechanically stable wound site with primary flap closure and circumferential seal is important to keep bacterial contaminants from the wound site and to aid in the bone graft material to not wash out. Emdogain is enamel matrix proteins obtained from pigs- it seems to encourage the formation of acellular cementum that is then followed by associated bone deposition. REFERENCE: Perio Syllabus 4th edition p. 168-172.
13). The hemiseptal defect is: a) A one-wall defect with one proximal wall b) A one-wall defect with one linguopalatal wall c) A one wall defect with one buccolabial wall d) A two walled defect with two proximal wallsAnswer: (a) A one-wall defect presents with either one proximal wall (hemiseptal) orone linguopalatal or buccolabial wall. These defects are generally not amenable toregenerative theraputic approaches. Resective therapy, with the goal of creating aphysiologic osseous architecture, will provide a more predictable and stable long-termresult.Two-wall defects are bordered by either two proximal walls, a buccal/labial and proximalwall or a buccal/labial and a lingual wall. A two-wall defect consisting of abuccal/labial and a lingual/palatal wall is commonly referred to as an interdental orosseous crater. The adjacent teeth are the other two walls of the defect. According to astudy by Manson and Nickolson, the interdental crater constitutes approximately onethird of all intrabony defects and as many as two thirds of all mandibular defects.Three-wall intrabony defects are characterized as having three osseous walls; the toothsurface constitutes the fourth wall. These defects may be localized to one proximal ormidradicular surface, or may be circumferental, involving two or more root surfaces. The typical clinical encounter is with a combination defect which combines two or moreof the above.Periodontal Therapy, Nevins and Mellonig, pp175,176
14). Which of the following statements are true regarding attachment levels anduprighting molars? a. Pockets mesial to uprighted molars are shallower than pockets mesial to control teeth that have not been uprighted. b. Gingival inflammation does not differ from that around control teeth. c. Trauma from occlusion with subsequent bone loss will occur with uprighted molars if selective equilibration is not performed. d. All of the aboveAnswer: d a. This is due to a reduction in soft tissue height while the bone height remains Unchanged. b. Same bugs, etiology c. Vertical loading results from moving the tooth’s occlusal surface toward the hinge. Selective equilibration and possible coronal restorations should be included in every treatment plan with a molar uprighting component.Clinical Periodontology, Carraza, Newman pp562, Periodontal Therapy, Nevins,Mellonig pp157
15). What is the most significant challenge regarding anterior implants? a. Difficulty in being able to use a fixture with adequately large enough diameter due to lack of bone. b. Securing the proper angulation of the fixture c. Getting an esthetically acceptable shade with a single tooth anterior implant. d. Avoiding the “black triangle” in the papilla area due to lack of bony support to the gingival contours. Answer: (d) Although a, b, and c are considerable challenges, the most challenging periodontal aspect is acceptable esthetic gingival contours due to a difference in crestal bone height between the implant and the adjacent natural tooth. GBR and connective tissue grafts are two treatments to correct this.B.C. CAPT John Mumford, USN, DC
16). Which of the following statements regarding Guided Tissue Regenerations are true? 1. Many teeth previously regarded as hopeless are salvageable via GTR using ePTFE 2. Class II furcation involvements, large three-walled infrabony defects, and osseous craters are predictably treatable with Gore Tex GTR 3. Routine uses of Gore Tex include two-walled defects and horizontal bone loss that may have been previously considered not salvageable 4. EPTFE titanium is used in wide deep infrabony defects and are best treated with a prerequisite adequate band of attached gingiva 5. Teeth that are amenable to Gore Tex membrane GTR include multirooted teeth with root proximity of greater than 1 mm 6. Gore-Tex regenerative membranes can be placed in transgingival and submerged configurations a. 4 only b. 4 and 5 only c. 4, 5, 6 d. 2, 3, 4, 5, 6 e. 1, 2, 4, 6Answer: (e) Today, many teeth previously regarded as hopeless are treatable via GTR.This includes the Class II furcations, large three walled infrabony defects and osseouscraters. Therefore, 1 and 2 are both true. 3 The first statement is true and the secondstatement is false. Horizontal bone loss is not amenable to GTR. If the interdental spaceis wide, the surgical procedure of choice is the modified papilla preservation technique.The interdental papilla is horizontally dissected at its base on the buccal side and elevatedwith a palatal full-thickness flap. After membranes positioning, the papilla is repositionedthough the interdental space to cover the barrier and possibly sutured to the buccal flap toobtain primary closure. If the interdental space is narrow, the simplified papillapreservations technique should be used. The interdental papilla is obliquely dissected toaugment the connectible tissue surface for the subsequent primary closure of the lap overthe barrier membrane. Anatomic prerequisites for an uneventful procedure include thepresence of adequate band of attached gingiva and absence of frena in the area oftreatment. 5 is false; the root proximity must be greater than 2 mm to be successful; inshallow defects (<2mm) between the roots of the adjacent teeth, little to no regenerationmay be obtained; analysis of the local site must be done to determine if a tooth istreatable; positive findings include: 1. adequate separation (>2mm) for access and to maintain collar. 2. an anatomy of the affected dental surface that allows good adaptation of the membrane and closure of the defect, 3. a good quantity of healthy periodontium remaining close to the defect and a thick periodontium and adulated vestibulum to allow for flap stability6 is true-titanium reinforced Gore-Tex regenerative membranes can be placed intransgingival and submerged configurations allowing extension through the gingiva orwhere the defect can be completely isolated.Nobel Biocare Gore Regenerative Materials Product Configuration Information; CriticalDecisions in Periodontology by Hall, 4th Ed. Chapters 37, 86, 87, 88, 89; Manual ofClinical Periodontics-Reference manual by Lexi-Comp
17). Page and Schroeder described several phases in the pathogenesis of periodontology;which one the statements is true? 1. The initial lesion is described as a classic chronic exudative vasculitis. 2. Within 4 to 10 days, the early lesion develops. It is characterized by a dense infiltrate of PMNs, pathologic alteration of fibroblasts, and an increase of the connective tissue substance 3. The established lesion develops within 2 to 3 months and is distinguished by a predominance of plasma cells and early horizontal bone loss. 4. In the advanced lesion, plasma cells continue to predominate although loss of the alveolar bone and periodontal ligament, and disruption of the tissue architecture with fibrosis are also important characteristics. a. 1 is correct b. 2 is correct c. 3 is correct d. 4 is correct Answer: (d) 1. False. The gingival tissues respond within 2 to 4 days to a beginning accumulation of microbial plaque with a classic acute exudative vasculitis which we have termed the initial lesion. 2. False. Within 4 to 10 days, the early lesion develops. This stage is characterized by a dense infiltrate of lymphocytes and other mononuclear cells, pathologic alteration of fibroblasts, and continuing loss of the connective tissue substance. The structural features of the early lesion are consistent with those expected in some form of cellular hypersensitivity, and a mechanism of this kind may be important in the pathogenesis. 3. False. The early lesion is followed by the established lesion which develops within 2 to 3 weeks and is distinguished by a predominance of plasma cells in the absence of significant bone loss. The established lesion, which is extremely widespread in humans and in animals, may remain stable for years or decades, or it may become converted into a progressive destructive lesion. Factors causing this conversion are not understood. 4. True. In the advanced lesion, plasma cells continue to predominate although loss of the alveolar bone and periodontal ligament, and disruption of the tissue architecture with fibrosis are also important characteristics. The initial, early, and established lesions are sequential stages in gingivitis and they, rather than the advanced lesion which is manifest clinically as periodontitis, make up the major portion of inflammatory gingival and periodontal disease in humans.Lab Invest. 1976 Mar;34(3):235-49.Pathogenesis of inflammatory periodontal disease. A summary of current work. Page RC,Schroeder HE.