Top 100-50 COPY Flashcards

1
Q

Kakehashi, 1965, OOO

A

The effects of surgical exposures of dental pulps in germ-free and conventional rats. 21 germ free rats healed after pulpal exposure, no apical pathosis found. 15 conventional developed pulpal necrosis. Presence of absence of microbial flora is the major determinant in the healing of exposed pulps.

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2
Q

Zack and Cohen, 1965, OOO

A

Pulp response to eternally applied heat. Monkeys. Heat was applied to teeth with soldering iron for periods of 5 to 20 seconds. Increase in internal temperature: 4 F; minimal pulpal changes at time of experiment, no distinguishable changes from normal teeth afterwards. 10 F; destruction and aspiration of odontoblasts into tubules, destruction of Tome’s fibrils. Recovery after 56 days but with scaring (irritation dentin). 20 F; complete disruption and destruction of odontoblast in the area. some developed pulpal abscess, others necrosis. Some developed dentoalveolar abscess 30 F; all teeth irreversible necrotic response. some severe dentoalveolar abscesses. Quantity and intensity of heat applied to pulp are important. Use coolant when drilling.

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3
Q

Sjogren, 1990, JOE

A

Factors affecting the long-term results of endo treatment. 356 pt’s 8-10 yrs after tx. Success rates: Vital/non-vital pulp w/o PARL; > 96% Necrotic with PARL= 86% Retreat with PARL= 62% Factors: Instrumentation to full length; 90% healing rate of PARL short; 69% healing rate of PARL Level of obturation; W/i 2mm of apex= 94% normal PA conditions overextended= 76% short = 68%

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4
Q

Sundqvist, 1998, OOO

A

Microbiological analysis of teeth with failed endo treatment and the outcome of conservative retreatment. 54 RCT teeth with persistent PARL were retreated, sampled and followed for 5 yrs. Microflora; Mainly single species of mostly G+. Most commonly found; E. faecalis (really?, no sh#$) Overall success rate = 74% flora of untreated teeth is different. Infection at the time of obturation and size of PARL had as significant negative influence on the prognosis. A. israelii associated with lack of healing of PARL.

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5
Q

Scheider, 1971, OOO

A

A comparison of canal preparations in straight and curved root canals. Degrees of root curvature: Straight = 5 degrees or less Moderate = 10-20 degrees Severe = 25 - 70 degrees Straight canals are much more readily prepared.

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6
Q

Sjogren, 1997, IEJ

A

Influence of infection at the time of root filling on the outcome of RCT of teeth with apical periodontitis. 55 single rooted teeth with apical periodontitis, instrumented and irrigated with NaOCl. Follow 5 yrs Success rate: Negative culture at time of obturation; 94% complete pa healing. Positive culture at time of obturation; 68% healing of pa lesion. Period of 4-5 years necessary to see the full impact of the persistent bacteria on the prognosis. Obturation should be delayed until after a suitable period of medication with an antimicrobial dressing to eradicate all infection which is impossible in one visit. ie. two visits are advocated.

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7
Q

Molander, 1998, IEJ

A

Microbial status of RCT with apical periodontitis. 100 RCT with PARL Predominant species; G+ Facultative anaerobic = 69% Most frequent species: E. faecalis Microflora of treated teeth varies from flora of untreated necrotic pulp quantitatively and qualitatively. Other causes of PARL: PA cyst, foreign body reaction, scar tissue. Use of CaOH between appointments to eliminate E. faecalis is probably not effective.

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8
Q

Torabinejad, 1995, JOE

A

Physical and chemical properties of a new root-end filling material. Chemical composition of MTA and comparison to amalgam, super EBA and IRM. MTA: Composition; tricalcium: silicate, aluminate and oxide, silicate oxide. Main molecules; Calcium and phosphorous ions (components of dental hard tissues)(biocompatible when used in contact with cells and tissues. pH; 10.2 initially, rises to 12.5 three hours after mixing.Induction of hard tissue formation might occur. Radiopacity; more than EBA and IRM Setting time; longest; 2h 45 min. Compressive strength; lowest at first, increases after 21 days to 67 MPa.

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9
Q

Ray and Trope, 1995, IEJ

A

Periapical status of RCTT in relation to the technical quality of the root filling and the coronal restoration. 1010 RCTT with permanent restorations were evaluated at Temple U in terms of quality of endo and coronal restoration. Best; GE and GR (91.4% API) Better; GR (80% API) Good; GE (75.7% API) The technical quality of the coronal restoration was significantly more important that the quality of the RCT for periodontal health. Good crown matters more than good endo. yeah right! API; Absence of periapical inflammation.

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10
Q

Walia, 1988, JOE

A

An initial investigation of the bending and torsional properties of NITI root canal files. NITI: Very low modulus of elasticity. Two to three times more elastic flexibility in bending and torsion and resistance to torsional fracture as compared to SS. Large elastic deformation before fracture. Superior fracture resistance is due to the ductility of NITi.

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11
Q

Torabinejad, 1999, JOE

A

Clinical applications of MTA (Raise the dead) *Prevents mircroleakage *Biocompatible *Promotes regeneration of original tissues when in contact with pulp or periradicular tissues. Applications: >Vital pulp therapy: pulp capping material; stimulates dentin bridge formation due to sealing ability, biocompatability, alkalinity. >Apical barrier (plug) in teeth with immature apexes. >Repair of root perforations; MTA has significantly less leakage than IRM or amalgam. >Root-end filling material; less inflammation, cementum formation over MTA, regeneration of PA tissues. Temporizing material. Repair vertical fractures.

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12
Q

Torabinejad, 1993, JOE

A

Sealing ability of a Mineral Trioxide Aggregate when used as a root end filling material. Dye penetration experiment with 30 extracted teeth to compare sealing ability of MTA, amalgam and super EBA. Result MTA leaked significantly less than amalgam or EBA.

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13
Q

Bystrom and Sundqvist, 1985, IEJ

A

The antibacterial action of NaOCL and EDTA in 60 cases of endo therapy. No significant difference in the use of 0.5 or 5.0% NaOCl as an antibacterial. Use of EDTA in combination with 5% NaOCl is more efficient than NaOCl alone. Fresh NaOCl should be applied frequently as it becos inactivated.

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14
Q

Nair, 1990, JOE

A

Intraradicular bacteria nd fungi in Root-filled, asymptomatic human teeth with therapy-resistant PARL. Light and E. microscope analysis of 9 therapy resistant teeth. Presence of intraradicular microorganisms (bacteria and fungi) in teeth with persistent pa lesions. Other non-healing lesions can be the involvement of a foreign body giant cell type.

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15
Q

Torabinejad, 1990, JOE

A

In vitro Bacterial penetration of coronary unsealed RCTT. 45 root canals were RCT via lateral condensation. Coronal portion was filled with S. epidermis and P. vulgaris. and time for complete bacterial penetration was recorded. 50% of root canals fully contaminated in: 19 day exposure to S. epidermidis 42 day exposure to P. vulgaris This study used the apparatus invented by Dr. Torabinejad that Dr. Chogle pointed out. Flask with a tooth suspended inside by a plastic barrier on the coronal portion. apex is submerged in liquid. Bacterial contamination has happened when liquid changed colors. Motility of bacteria is not a factor in the rate of penetration.

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16
Q

Vertucci, 1984, OOO

A

Root canal anatomy of the human permanent teeth.

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17
Q

Sjogren, 1991, IEJ

A

The antimicrobial effect of CaOH as a short term intracranial dressing. 30 teeth with necrotic pulps, PARL. 12 cases treated with CaOH for 10 minutes. 18 cases treated with CaOH for 7 days. Teeth were sampled under anaerobic conditions. 10 minutes; treatment was ineffective, bacteria was still present at second appointment. 7 days; bacteria could not be recovered 1-5 days after removal of dressing or immediately afterwards. Facultative anaerobic isolate was E. faecalis.

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18
Q

Wang and Hume, 1988 Unrelated to top 100

A

Buffering capacity of hydroxyapatite prevents the readily diffusion of CaOH ions. buffering can eventually be overcome given sufficient availability of hydroxyl ions over time.

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19
Q

Pruett, 1997, JOE

A

Cyclic fatigue testing of NITI endo instruments. Factors affecting cyclic fatigue” Most to least in predicting instrument separation *Radius of curvature; as radius of curvature decreased so did amount of cycles to failure. *Angle of curvature; As angle decreases so does amount of cycles to failure. Instrument shaft diameter; As diameter increased cycles to failure decreased. Operating RPM

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20
Q

Orstavik and Haapasalo, 1990,

A

Disinfection by endodontic irritants and dressings of experimentally infected dentinal tubules. Bovine dentin specimens infected with E. faecalis, S sangis, E. coli or P. aeruginosa. Specimens were infected for up to 14 days and degree of infection was monitored. E. faecalis; rapid infection of the whole length and survival after removal of nutrients. S. sanguis; 2 weeks for complete infection. E.coli; only penetrated 600µm. except for E.faecalis all other organisms died after 4 to 48 hrs. IKI more potent than NaOCl or CHI. Presence of smear layer delayed but did not eliminate the effect of the medicaments.

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21
Q

Wu and Wesselink, 1993, IEJ

A

Endodontic leakage studies reconsidered More research is needed on the methodology of leakage studies. Way too many studies in the 80 and 90s with varying results that provide little relevant information.

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22
Q

Roane, 1985, JOE

A

The Balanced force concept for instrumentation of curved canals. Balanced force was derived from the law; for every action there is an equal and opposite reaction. Magnitude of the restoring force is a function of: File’s mass Geometry composition Radius and arc of instrumentation curve. Placement is accomplished using CW rotation no more than 180 degrees with light inward pressure. Cutting is accomplished using CCW rotation of at least 120 degrees and inward pressure. Cleaning or debris removal is accomplished using one or two non cutting, no pressure outward pull clockwise rotation. Balance force allows you to produce enlargement of canals past severe curvatures.

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23
Q

Bystrom, 1983, OOO

A

Bacteriologic evaluation of math effect for 0.5 % NaOCl in endodontic therapy. No bacteria could be recovered from 12 out of 15 root canals at the fifth appointment when NaOCl was used No bacteria could be recovered from 8 out of 15 root canals when saline was used NaOCl is more effective than saline. 88% of strains recovered were anaerobic. Most common; F. nucleatum Closed RCS seems to be a selective milieu where the composition of the flora is influenced by: Changes in anaerobiosis. nutritional interrelationships. More studies are needed to evaluate higher concentrations of NaOCl.

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24
Q

Pineda and Kutler, 1972, OOO

A

Mesiodistal and buccolingual roentgenographic investigation of 7275 root canals. Apical Exit: 16.9% Lateral exit: 83% (6018 Canals) Apical foramen diameter increases with age Most canals are curved and cone shaped.

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25
Q

Shipper, 2004, JOE

A

An evaluation of microbial leakage in roots filled with Resilon. compare bacterial leakage through GP and resilon using S. mutant and E. faecalis. Resilon; thermoplastic synthetic polymer of polyester. Epiphany; Dual cure dental resin composite sealer. 40 sec of light will cure the coronal 2 mm, entire fill will cure in approx 15 to 30 min. Resilon can be removed with chloroform. Resilon is very compatible since it can be used for tissue engineering but it can also be degraded by the body. Polymerization is never 100% Resin tags into dentin to form mono block.

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26
Q

Lee, 1993, JOE Torabinejad was the third author

A

Sealing ability of MTA for repair of lateral root perforations Comparison of amalgam, IRM and MTA 50 extracted teeth were repaired after creating a lateral root perforation and them placed in saline for four weeks. Factors that affect prognosis of repair Contamination of perforation site Location Size Operator skill Material of choice. MTA performed better than the other two materials.

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27
Q

Glosson, 1995, JOE

A

A comparison of RC preparations using NITI hand and engine driven and k-flex endo instruments. Canal curvature and shape: no significant difference with the different instruments. Canal transportation; Less with NITI rotary instruments. SS instruments are able to negotiate obstructions better because they do not bend, also better tactile sensation.

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28
Q

Saunders and Saunders, 1994

A

Coronal leakage as a cause of failure in RCT. A review More important to seal the coronal part of molars with glass ionomer due to the presence of accessory canals in this area It is important to remove the smear layer because it can be broken down by bacterial toxins Crown of tooth should be restored expeditiously. Temp material should be at least 3.5 mm thick. Chemically active adhesives might play an important role in the future.

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29
Q

Sundqvist, Johansson and Sjogren, 1989

A

Prevalence of Black-pigmented bacteroides species in root canal infections. Positive association between black-pigmented Bactroides species and apical abscess formation

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30
Q

Tronstad, 1988,

A

Root resorption - etiology, terminology and clinical manifestations. Classifications: Inflammatory; Precementum or Predentin become mineralized, could be internal or external. Either transient or progressive and it requires an intervention to stop it. Replacement; seen it teeth that have become ankylosed and incorporated into the bone. Transient; Occurs as a result of trauma, ortho, perio tx, self limiting to 2-3 weeks. Not clinically significant. Progressive inflammatory; due to continued stimulation to resorbing cells such as mechanical, pressure, infection or systemic diseases. Internal resorption; takes place w/i RCS after loss of predentin and odontoblast layer. uncommon in permanent teeth. external resorption; can be progressive, vertical or replacement.

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31
Q

Torabinejad, 1997, JOE

A

Histologic assessment of MTA as a root-end filling in monkeys. MTA had cementum deposition and PDL attachment. Amalgam did not prevent micro leakage and did not allow for regeneration of dentinoalveolar tissues.

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32
Q

Torabinejad, 1995, JOE

A

Investigation of Mineral Trioxide Aggregate for Root-End Filling in Dogs. Regeneration of cementum over MTA MTA is probably capable of the activation of cementoblast.

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33
Q

Spangber, 1973, OOO

A

Biologic effects of dental materials. Toxicity and antimicrobial effect of endo antiseptics in vitro Toxic effects of NaOCl, CHI, Iodopax are 10X grater than their antimicrobial effects NaOCl at 5% is highly toxic and irritating to the tissue, dissolves necrotic and vital tissue. Lower concentrations should be considered. Chlorhexidine; low toxicity but minimal cleansing effect. Iodine solutions might discolor tooth and patient might be hypersesitive.

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34
Q

Swanson and Madison, 1987, JOE

A

An Evaluation of Coronal Microleakage in Endodontically Treated Teeth. Part I. Time Periods Evaluation of micro leakage when obturation material are exposed to fluids. Significant amount of micro leakage is evident after three days of exposure to saliva.

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35
Q

Reset

A

Reset

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36
Q

Baumgartner, 1987, JOE

A

A Scanning Electron Microscopic Evaluation of Four Root Canal Irrigation Regimens. Compare debriment capabilities of saline, 5.25% NaOCl, 15% EDTA and combinations. EDTA removes smear layer but not organic material. NaOCl removes organic debris and its antibacterial but does not remove SL. Alternating EDTA and NaOCL effectively removes smear layer, tissue, predentin and increases antimicrobial activity

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37
Q

Torabinejad, 1995, JOE

A

Bacterial leakage of mineral trioxide aggregate as a root-end filling material. Compare bacterial leakage potential of amalgam, Super-EBA, IRM, and MTA. EBA, IRM and amalgam showed leakage at 6-57 days. MTA showed no leakage at 90 days.

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38
Q

Koh, 1998, JOE Torabinejad was fifth author.

A

Cellular response to mineral trioxide aggregate. IRM; cytotoxic, cell death in three days when in contact. MTA; Biocompatible, cells remained healthy when in contact. Increases presence of presence of cytokines: IL1a, IL1b and IL6. promotes cytokine release from osteoblasts.

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39
Q

Schwartz, 2004, JOE

A

Post Placement and Restoration of Endodontically Treated Teeth. Retrievability easiness; metal>fiber>ceramic/zirconium basically impossible Post length should be equal to ¾ length of the root or at least the length of the crown but no less than 8mm or longer than 4 to 5 mm from apex to maintain adequate seal. A 1 mm of vertical height ferrule doubles the resistance to fracture. Maximum benefit achieved with 1.5 to 2 mm ferrule

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40
Q

Sundqvist, 1994,OOO

A

Taxonomy, ecology and pathogenicity of the root canal flora. The bacterial synergy is an important factor in determining the pathogenicity of the polymicrobial root canal floral Most common bacteria; Peptostreptococci (micros and anaerobicus ) · Gram pos, anaerobic, non spore forming. Most frequently isolated species from intact canals; Fusobacterium nucleatum Most common in treatment failure; A. israelii due to its ability to establish infections in the periapical tissues.

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41
Q

Sundqvist, 1992, JOE

A

Ecology of the root canal flora. The factors may influence the ecology of the root canal bacteria composition 1. Number of bacteria species is in proportion to the apical lesion size. 2. The root canal environment is dynamic and selective. (e.g. the relative proportion of anaerobic bacterial strains increased with time) 3. Bacterial interrelationships: both positive and negative influences (e.g. F. nucleatum is positively related to P. micros, W. recta, P. endodontalis, and S. sputigena) (e.g. A. israelii is positively related to P. propionicus,) 4. Nutrition supply: different phase of infection provides different kind of nutrition to bacteria First: Glucose/F. Nucleatum Second: Glycoproteins/B. Intermedius Third: Amino acid and peptide/P. Micros 5. Bacteriocins: Some species produce bacteriocins (protein) and inhibit other species (e.g. P. endodontalis inhibits the growth of B. intermedius) 6. Endodontic treatment

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42
Q

Torabinejad, 1994, JOE

A

Dye Leakage of Four Root End Filling Materials: Effects of Blood Contamination. MTA leaked significantly less than other tested materials as an retro-filling material, and the result was not affected by blood contamination

43
Q

Reset

A

Reset

44
Q

Ciucchi, 1995, JOE

A

Dentinal Fluid Dynamics in Human Teeth, In Vivo 5 first and second mandibular bicuspids in children 12-15. Class V preparation. Hydraulic apparatus to evaluate pulpal pressure in vivo All five teeth exhibited an outwardly directed fluid flow when exogenous pressure was set at 0. Mean value of the spontaneous fluid flow was 0.36µl min-1 cm-2 .

45
Q

Ree, 1989, JOE

A

Reduction in Tooth Stiffness as a Result of Endodontic and Restorative Procedures.

46
Q

Peters, 2004, JOE

A

Current Challenges and Concepts in the Preparation of Root Canal Systems: A Review Main issues • Identification, accessing, and enlargement of the main canals without procedural errors • Establishing and maintaining adequate working lengths through- out the shaping procedure • Selection of preparation sizes and overall geometries that allow adequate disinfection and subsequent obturation. Results. NiTi instruments clinically showed a low incidence of preparation errors, satisfactory obturation as judged from radiographs, and significantly improved healing com- pared with a control group treated with stainless-steel instruments

47
Q

Sattapan, 2000, JOE

A

Defects in Rotary Nickel-Titanium Files After Clinical Use 378 used files analyzed, used by one endodontist. 50% showed some defect 21% were fractured, of those Torsional fracture = 56% perhaps due to too much apical pressure during instrumentation. Flexural fatigue = 44% usually in larger instruments, just like Pruett study Conclusion; Use light apical pressure. Do not keep instrument rotating in the same position for an extended period of time. Examine each instrument before use.

48
Q

Torabinejad, 1995, JOE

A

Cytotoxicity of four root end filling materials. Compared; Amalgam, EBA, IRM and MTA Amalgam was less cytotoxic fresh and set followed by MTA. 24 hrs later from less to most cytotoxic: Amalgam, MTA, EBA, IRM

49
Q

Ford, 1995, OOO Torabinejad is second author

A

Use of MTA for the repair of furcal perforations. 30 furcal perfs on 7 beagle dogs. As per Ingle, perforations are the second greatest cause of failure; 10%. Perf of apical and middle third have a better prognosis. Favorable response to MTA if filled immediately, including cementum formation over MTA and PDL attachment. Poor prognosis due to infection if repair is delayed, epitheleal proliferation was seen in this group.

50
Q

Standlee and Caputo, 1972

A

Analysis of stress distribution by endodontic posts threaded posts generate a high level of stress but best stress distribution at short lengths. Tappered posts exhibit a wedging effect. Parallel posts generate the highest apical stress.

51
Q

Goldman, 1972, Tufs

A

Endodontic success, Who is reading the radiograph. 6 examiners, 253 cases. Agreement was reached in less than half the cases.

52
Q

Nair, 2005

A

Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after “one-visit” endodontic treatment. anatomical complexity of the RCS and organization of microflora under biofilm prevent the complete removal by instrumentation and irrigants in a single visit.

53
Q

The effects of surgical exposures of dental pulps in germ-free and conventional rats. 21 germ free rats healed after pulpal exposure, no apical pathosis found. 15 conventional developed pulpal necrosis. Presence of absence of microbial flora is the major determinant in the healing of exposed pulps.

A

Kakehashi, 1965, OOO

54
Q

Pulp response to eternally applied heat. Monkeys. Heat was applied to teeth with soldering iron for periods of 5 to 20 seconds. Increase in internal temperature: 4 F; minimal pulpal changes at time of experiment, no distinguishable changes from normal teeth afterwards. 10 F; destruction and aspiration of odontoblasts into tubules, destruction of Tome’s fibrils. Recovery after 56 days but with scaring (irritation dentin). 20 F; complete disruption and destruction of odontoblast in the area. some developed pulpal abscess, others necrosis. Some developed dentoalveolar abscess 30 F; all teeth irreversible necrotic response. some severe dentoalveolar abscesses. Quantity and intensity of heat applied to pulp are important. Use coolant when drilling.

A

Zack and Cohen, 1965, OOO

55
Q

Factors affecting the long-term results of endo treatment. 356 pt’s 8-10 yrs after tx. Success rates: Vital/non-vital pulp w/o PARL; > 96% Necrotic with PARL= 86% Retreat with PARL= 62% Factors: Instrumentation to full length; 90% healing rate of PARL short; 69% healing rate of PARL Level of obturation; W/i 2mm of apex= 94% normal PA conditions overextended= 76% short = 68%

A

Sjogren, 1990, JOE

56
Q

Microbiological analysis of teeth with failed endo treatment and the outcome of conservative retreatment. 54 RCT teeth with persistent PARL were retreated, sampled and followed for 5 yrs. Microflora; Mainly single species of mostly G+. Most commonly found; E. faecalis (really?, no sh#$) Overall success rate = 74% flora of untreated teeth is different. Infection at the time of obturation and size of PARL had as significant negative influence on the prognosis. A. israelii associated with lack of healing of PARL.

A

Sundqvist, 1998, OOO

57
Q

A comparison of canal preparations in straight and curved root canals. Degrees of root curvature: Straight = 5 degrees or less Moderate = 10-20 degrees Severe = 25 - 70 degrees Straight canals are much more readily prepared.

A

Scheider, 1971, OOO

58
Q

Influence of infection at the time of root filling on the outcome of RCT of teeth with apical periodontitis. 55 single rooted teeth with apical periodontitis, instrumented and irrigated with NaOCl. Follow 5 yrs Success rate: Negative culture at time of obturation; 94% complete pa healing. Positive culture at time of obturation; 68% healing of pa lesion. Period of 4-5 years necessary to see the full impact of the persistent bacteria on the prognosis. Obturation should be delayed until after a suitable period of medication with an antimicrobial dressing to eradicate all infection which is impossible in one visit. ie. two visits are advocated.

A

Sjogren, 1997, IEJ

59
Q

Microbial status of RCT with apical periodontitis. 100 RCT with PARL Predominant species; G+ Facultative anaerobic = 69% Most frequent species: E. faecalis Microflora of treated teeth varies from flora of untreated necrotic pulp quantitatively and qualitatively. Other causes of PARL: PA cyst, foreign body reaction, scar tissue. Use of CaOH between appointments to eliminate E. faecalis is probably not effective.

A

Molander, 1998, IEJ

60
Q

Physical and chemical properties of a new root-end filling material. Chemical composition of MTA and comparison to amalgam, super EBA and IRM. MTA: Composition; tricalcium: silicate, aluminate and oxide, silicate oxide. Main molecules; Calcium and phosphorous ions (components of dental hard tissues)(biocompatible when used in contact with cells and tissues. pH; 10.2 initially, rises to 12.5 three hours after mixing.Induction of hard tissue formation might occur. Radiopacity; more than EBA and IRM Setting time; longest; 2h 45 min. Compressive strength; lowest at first, increases after 21 days to 67 MPa.

A

Torabinejad, 1995, JOE

61
Q

Periapical status of RCTT in relation to the technical quality of the root filling and the coronal restoration. 1010 RCTT with permanent restorations were evaluated at Temple U in terms of quality of endo and coronal restoration. Best; GE and GR (91.4% API) Better; GR (80% API) Good; GE (75.7% API) The technical quality of the coronal restoration was significantly more important that the quality of the RCT for periodontal health. Good crown matters more than good endo. yeah right! API; Absence of periapical inflammation.

A

Ray and Trope, 1995, IEJ

62
Q

An initial investigation of the bending and torsional properties of NITI root canal files. NITI: Very low modulus of elasticity. Two to three times more elastic flexibility in bending and torsion and resistance to torsional fracture as compared to SS. Large elastic deformation before fracture. Superior fracture resistance is due to the ductility of NITi.

A

Walia, 1988, JOE

63
Q

Clinical applications of MTA (Raise the dead) *Prevents mircroleakage *Biocompatible *Promotes regeneration of original tissues when in contact with pulp or periradicular tissues. Applications: >Vital pulp therapy: pulp capping material; stimulates dentin bridge formation due to sealing ability, biocompatability, alkalinity. >Apical barrier (plug) in teeth with immature apexes. >Repair of root perforations; MTA has significantly less leakage than IRM or amalgam. >Root-end filling material; less inflammation, cementum formation over MTA, regeneration of PA tissues. Temporizing material. Repair vertical fractures.

A

Torabinejad, 1999, JOE

64
Q

Sealing ability of a Mineral Trioxide Aggregate when used as a root end filling material. Dye penetration experiment with 30 extracted teeth to compare sealing ability of MTA, amalgam and super EBA. Result MTA leaked significantly less than amalgam or EBA.

A

Torabinejad, 1993, JOE

65
Q

The antibacterial action of NaOCL and EDTA in 60 cases of endo therapy. No significant difference in the use of 0.5 or 5.0% NaOCl as an antibacterial. Use of EDTA in combination with 5% NaOCl is more efficient than NaOCl alone. Fresh NaOCl should be applied frequently as it becos inactivated.

A

Bystrom and Sundqvist, 1985, IEJ

66
Q

Intraradicular bacteria nd fungi in Root-filled, asymptomatic human teeth with therapy-resistant PARL. Light and E. microscope analysis of 9 therapy resistant teeth. Presence of intraradicular microorganisms (bacteria and fungi) in teeth with persistent pa lesions. Other non-healing lesions can be the involvement of a foreign body giant cell type.

A

Nair, 1990, JOE

67
Q

In vitro Bacterial penetration of coronary unsealed RCTT. 45 root canals were RCT via lateral condensation. Coronal portion was filled with S. epidermis and P. vulgaris. and time for complete bacterial penetration was recorded. 50% of root canals fully contaminated in: 19 day exposure to S. epidermidis 42 day exposure to P. vulgaris This study used the apparatus invented by Dr. Torabinejad that Dr. Chogle pointed out. Flask with a tooth suspended inside by a plastic barrier on the coronal portion. apex is submerged in liquid. Bacterial contamination has happened when liquid changed colors. Motility of bacteria is not a factor in the rate of penetration.

A

Torabinejad, 1990, JOE

68
Q

Root canal anatomy of the human permanent teeth.

A

Vertucci, 1984, OOO

69
Q

The antimicrobial effect of CaOH as a short term intracranial dressing. 30 teeth with necrotic pulps, PARL. 12 cases treated with CaOH for 10 minutes. 18 cases treated with CaOH for 7 days. Teeth were sampled under anaerobic conditions. 10 minutes; treatment was ineffective, bacteria was still present at second appointment. 7 days; bacteria could not be recovered 1-5 days after removal of dressing or immediately afterwards. Facultative anaerobic isolate was E. faecalis.

A

Sjogren, 1991, IEJ

70
Q

Buffering capacity of hydroxyapatite prevents the readily diffusion of CaOH ions. buffering can eventually be overcome given sufficient availability of hydroxyl ions over time.

A

Wang and Hume, 1988 Unrelated to top 100

71
Q

Cyclic fatigue testing of NITI endo instruments. Factors affecting cyclic fatigue” Most to least in predicting instrument separation *Radius of curvature; as radius of curvature decreased so did amount of cycles to failure. *Angle of curvature; As angle decreases so does amount of cycles to failure. Instrument shaft diameter; As diameter increased cycles to failure decreased. Operating RPM

A

Pruett, 1997, JOE

72
Q

Disinfection by endodontic irritants and dressings of experimentally infected dentinal tubules. Bovine dentin specimens infected with E. faecalis, S sangis, E. coli or P. aeruginosa. Specimens were infected for up to 14 days and degree of infection was monitored. E. faecalis; rapid infection of the whole length and survival after removal of nutrients. S. sanguis; 2 weeks for complete infection. E.coli; only penetrated 600µm. except for E.faecalis all other organisms died after 4 to 48 hrs. IKI more potent than NaOCl or CHI. Presence of smear layer delayed but did not eliminate the effect of the medicaments.

A

Orstavik and Haapasalo, 1990,

73
Q

Endodontic leakage studies reconsidered More research is needed on the methodology of leakage studies. Way too many studies in the 80 and 90s with varying results that provide little relevant information.

A

Wu and Wesselink, 1993, IEJ

74
Q

The Balanced force concept for instrumentation of curved canals. Balanced force was derived from the law; for every action there is an equal and opposite reaction. Magnitude of the restoring force is a function of: File’s mass Geometry composition Radius and arc of instrumentation curve. Placement is accomplished using CW rotation no more than 180 degrees with light inward pressure. Cutting is accomplished using CCW rotation of at least 120 degrees and inward pressure. Cleaning or debris removal is accomplished using one or two non cutting, no pressure outward pull clockwise rotation. Balance force allows you to produce enlargement of canals past severe curvatures.

A

Roane, 1985, JOE

75
Q

Bacteriologic evaluation of math effect for 0.5 % NaOCl in endodontic therapy. No bacteria could be recovered from 12 out of 15 root canals at the fifth appointment when NaOCl was used No bacteria could be recovered from 8 out of 15 root canals when saline was used NaOCl is more effective than saline. 88% of strains recovered were anaerobic. Most common; F. nucleatum Closed RCS seems to be a selective milieu where the composition of the flora is influenced by: Changes in anaerobiosis. nutritional interrelationships. More studies are needed to evaluate higher concentrations of NaOCl.

A

Bystrom, 1983, OOO

76
Q

Mesiodistal and buccolingual roentgenographic investigation of 7275 root canals. Apical Exit: 16.9% Lateral exit: 83% (6018 Canals) Apical foramen diameter increases with age Most canals are curved and cone shaped.

A

Pineda and Kutler, 1972, OOO

77
Q

An evaluation of microbial leakage in roots filled with Resilon. compare bacterial leakage through GP and resilon using S. mutant and E. faecalis. Resilon; thermoplastic synthetic polymer of polyester. Epiphany; Dual cure dental resin composite sealer. 40 sec of light will cure the coronal 2 mm, entire fill will cure in approx 15 to 30 min. Resilon can be removed with chloroform. Resilon is very compatible since it can be used for tissue engineering but it can also be degraded by the body. Polymerization is never 100% Resin tags into dentin to form mono block.

A

Shipper, 2004, JOE

78
Q

Sealing ability of MTA for repair of lateral root perforations Comparison of amalgam, IRM and MTA 50 extracted teeth were repaired after creating a lateral root perforation and them placed in saline for four weeks. Factors that affect prognosis of repair Contamination of perforation site Location Size Operator skill Material of choice. MTA performed better than the other two materials.

A

Lee, 1993, JOE Torabinejad was the third author

79
Q

A comparison of RC preparations using NITI hand and engine driven and k-flex endo instruments. Canal curvature and shape: no significant difference with the different instruments. Canal transportation; Less with NITI rotary instruments. SS instruments are able to negotiate obstructions better because they do not bend, also better tactile sensation.

A

Glosson, 1995, JOE

80
Q

Coronal leakage as a cause of failure in RCT. A review More important to seal the coronal part of molars with glass ionomer due to the presence of accessory canals in this area It is important to remove the smear layer because it can be broken down by bacterial toxins Crown of tooth should be restored expeditiously. Temp material should be at least 3.5 mm thick. Chemically active adhesives might play an important role in the future.

A

Saunders and Saunders, 1994

81
Q

Prevalence of Black-pigmented bacteroides species in root canal infections. Positive association between black-pigmented Bactroides species and apical abscess formation

A

Sundqvist, Johansson and Sjogren, 1989

82
Q

Root resorption - etiology, terminology and clinical manifestations. Classifications: Inflammatory; Precementum or Predentin become mineralized, could be internal or external. Either transient or progressive and it requires an intervention to stop it. Replacement; seen it teeth that have become ankylosed and incorporated into the bone. Transient; Occurs as a result of trauma, ortho, perio tx, self limiting to 2-3 weeks. Not clinically significant. Progressive inflammatory; due to continued stimulation to resorbing cells such as mechanical, pressure, infection or systemic diseases. Internal resorption; takes place w/i RCS after loss of predentin and odontoblast layer. uncommon in permanent teeth. external resorption; can be progressive, vertical or replacement.

A

Tronstad, 1988,

83
Q

Histologic assessment of MTA as a root-end filling in monkeys. MTA had cementum deposition and PDL attachment. Amalgam did not prevent micro leakage and did not allow for regeneration of dentinoalveolar tissues.

A

Torabinejad, 1997, JOE

84
Q

Investigation of Mineral Trioxide Aggregate for Root-End Filling in Dogs. Regeneration of cementum over MTA MTA is probably capable of the activation of cementoblast.

A

Torabinejad, 1995, JOE

85
Q

Biologic effects of dental materials. Toxicity and antimicrobial effect of endo antiseptics in vitro Toxic effects of NaOCl, CHI, Iodopax are 10X grater than their antimicrobial effects NaOCl at 5% is highly toxic and irritating to the tissue, dissolves necrotic and vital tissue. Lower concentrations should be considered. Chlorhexidine; low toxicity but minimal cleansing effect. Iodine solutions might discolor tooth and patient might be hypersesitive.

A

Spangber, 1973, OOO

86
Q

An Evaluation of Coronal Microleakage in Endodontically Treated Teeth. Part I. Time Periods Evaluation of micro leakage when obturation material are exposed to fluids. Significant amount of micro leakage is evident after three days of exposure to saliva.

A

Swanson and Madison, 1987, JOE

87
Q

Reset

A

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88
Q

A Scanning Electron Microscopic Evaluation of Four Root Canal Irrigation Regimens. Compare debriment capabilities of saline, 5.25% NaOCl, 15% EDTA and combinations. EDTA removes smear layer but not organic material. NaOCl removes organic debris and its antibacterial but does not remove SL. Alternating EDTA and NaOCL effectively removes smear layer, tissue, predentin and increases antimicrobial activity

A

Baumgartner, 1987, JOE

89
Q

Bacterial leakage of mineral trioxide aggregate as a root-end filling material. Compare bacterial leakage potential of amalgam, Super-EBA, IRM, and MTA. EBA, IRM and amalgam showed leakage at 6-57 days. MTA showed no leakage at 90 days.

A

Torabinejad, 1995, JOE

90
Q

Cellular response to mineral trioxide aggregate. IRM; cytotoxic, cell death in three days when in contact. MTA; Biocompatible, cells remained healthy when in contact. Increases presence of presence of cytokines: IL1a, IL1b and IL6. promotes cytokine release from osteoblasts.

A

Koh, 1998, JOE Torabinejad was fifth author.

91
Q

Post Placement and Restoration of Endodontically Treated Teeth. Retrievability easiness; metal>fiber>ceramic/zirconium basically impossible Post length should be equal to ¾ length of the root or at least the length of the crown but no less than 8mm or longer than 4 to 5 mm from apex to maintain adequate seal. A 1 mm of vertical height ferrule doubles the resistance to fracture. Maximum benefit achieved with 1.5 to 2 mm ferrule

A

Schwartz, 2004, JOE

92
Q

Taxonomy, ecology and pathogenicity of the root canal flora. The bacterial synergy is an important factor in determining the pathogenicity of the polymicrobial root canal floral Most common bacteria; Peptostreptococci (micros and anaerobicus ) · Gram pos, anaerobic, non spore forming. Most frequently isolated species from intact canals; Fusobacterium nucleatum Most common in treatment failure; A. israelii due to its ability to establish infections in the periapical tissues.

A

Sundqvist, 1994,OOO

93
Q

Ecology of the root canal flora. The factors may influence the ecology of the root canal bacteria composition 1. Number of bacteria species is in proportion to the apical lesion size. 2. The root canal environment is dynamic and selective. (e.g. the relative proportion of anaerobic bacterial strains increased with time) 3. Bacterial interrelationships: both positive and negative influences (e.g. F. nucleatum is positively related to P. micros, W. recta, P. endodontalis, and S. sputigena) (e.g. A. israelii is positively related to P. propionicus,) 4. Nutrition supply: different phase of infection provides different kind of nutrition to bacteria First: Glucose/F. Nucleatum Second: Glycoproteins/B. Intermedius Third: Amino acid and peptide/P. Micros 5. Bacteriocins: Some species produce bacteriocins (protein) and inhibit other species (e.g. P. endodontalis inhibits the growth of B. intermedius) 6. Endodontic treatment

A

Sundqvist, 1992, JOE

94
Q

Dye Leakage of Four Root End Filling Materials: Effects of Blood Contamination. MTA leaked significantly less than other tested materials as an retro-filling material, and the result was not affected by blood contamination

A

Torabinejad, 1994, JOE

95
Q

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A

Reset

96
Q

Dentinal Fluid Dynamics in Human Teeth, In Vivo 5 first and second mandibular bicuspids in children 12-15. Class V preparation. Hydraulic apparatus to evaluate pulpal pressure in vivo All five teeth exhibited an outwardly directed fluid flow when exogenous pressure was set at 0. Mean value of the spontaneous fluid flow was 0.36µl min-1 cm-2 .

A

Ciucchi, 1995, JOE

97
Q

Reduction in Tooth Stiffness as a Result of Endodontic and Restorative Procedures.

A

Ree, 1989, JOE

98
Q

Current Challenges and Concepts in the Preparation of Root Canal Systems: A Review Main issues • Identification, accessing, and enlargement of the main canals without procedural errors • Establishing and maintaining adequate working lengths through- out the shaping procedure • Selection of preparation sizes and overall geometries that allow adequate disinfection and subsequent obturation. Results. NiTi instruments clinically showed a low incidence of preparation errors, satisfactory obturation as judged from radiographs, and significantly improved healing com- pared with a control group treated with stainless-steel instruments

A

Peters, 2004, JOE

99
Q

Defects in Rotary Nickel-Titanium Files After Clinical Use 378 used files analyzed, used by one endodontist. 50% showed some defect 21% were fractured, of those Torsional fracture = 56% perhaps due to too much apical pressure during instrumentation. Flexural fatigue = 44% usually in larger instruments, just like Pruett study Conclusion; Use light apical pressure. Do not keep instrument rotating in the same position for an extended period of time. Examine each instrument before use.

A

Sattapan, 2000, JOE

100
Q

Cytotoxicity of four root end filling materials. Compared; Amalgam, EBA, IRM and MTA Amalgam was less cytotoxic fresh and set followed by MTA. 24 hrs later from less to most cytotoxic: Amalgam, MTA, EBA, IRM

A

Torabinejad, 1995, JOE

101
Q

Use of MTA for the repair of furcal perforations. 30 furcal perfs on 7 beagle dogs. As per Ingle, perforations are the second greatest cause of failure; 10%. Perf of apical and middle third have a better prognosis. Favorable response to MTA if filled immediately, including cementum formation over MTA and PDL attachment. Poor prognosis due to infection if repair is delayed, epitheleal proliferation was seen in this group.

A

Ford, 1995, OOO Torabinejad is second author

102
Q

Analysis of stress distribution by endodontic posts threaded posts generate a high level of stress but best stress distribution at short lengths. Tappered posts exhibit a wedging effect. Parallel posts generate the highest apical stress.

A

Standlee and Caputo, 1972

103
Q

Endodontic success, Who is reading the radiograph. 6 examiners, 253 cases. Agreement was reached in less than half the cases.

A

Goldman, 1972, Tufs

104
Q

Microbial status of apical root canal system of human mandibular first molars with primary apical periodontitis after “one-visit” endodontic treatment. anatomical complexity of the RCS and organization of microflora under biofilm prevent the complete removal by instrumentation and irrigants in a single visit.

A

Nair, 2005