Top 100-53 Flashcards
- Kakehashi, 1965, OOO
In vivo, rat study. Presence of absence of microbial flora is the major determinant in the healing of exposed pulps. 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.
- Zack and Cohen, 1965, OOO
In vivo, Monkey study. Temperature increase of 10 degree or more could cause irreversible damage to odontoblasts. 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.
- Sjogren, 1990, JOE
Radiograph study. 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%
- Sundqvist, 1998, OOO
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% for retreat. 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.
- Schneider, 1971, OOO
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.
- Sjogren, 1997, IEJ
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.
Molander, 1998, IEJ
Microflora of the obturated canal differs from that found normally in the untreated necrotic dental pulp. Microbial status of RCT with apical periodontitis. 100 RCT with PARL Predominant species; Mostly 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.
Torabinejad, 1995, JOE
Physical and chemical properties of a new root-end filling material. Setting time, compressive strength, and solubility 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. 3 hours setting time.
Ray and Trope, 1995, IEJ
Radiographic study. 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) PE and PR 18%. 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. GE PR, 44%; PE, GR, 68%
Walia, 1988, JOE
An initial investigation of the bending and torsional properties of NITI root canal files. #15 size file was used. 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.
- Torabinejad, 1999, JOE
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.
- Torabinejad, 1993, JOE
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.
- Bystrom and Sundqvist, 1985, IEJ
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 becomes inactivated.
- Nair, 1990, JOE
Light and electron microscopic study. Apical root canal bacteria and 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.
- Torabinejad, 1990, JOE
In vitro Bacterial penetration of coronary unsealed RC. 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.
- Vertucci, 1984, OOO
Root canal anatomy of the human permanent teeth.
- Sjogren and Sundqvist, 1991, IEJ
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.
Wang and Hume, 1988 Unrelated to top 100
Buffering capacity of hydroxyapatite prevents the readily diffusion of CaOH ions. buffering can eventually be overcome given sufficient availability of hydroxyl ions over time.
- Pruett, 1997, JOE
Cyclic fatigue (NiTi instruments fracture within their elastic limit and without any signs of previous permanent distortion. at height of curvature) 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. #30 and #40 files. 30, 45, and 60 degree of curvatures were tested.
- Orstavik and Haapasalo, 1990
E. faecalis penetrates dentinal tubules fast and deep, also hard to eliminate. 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.
- Wu and Wesselink, 1993, IEJ
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.
- Roane, 1985, JOE
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.
- Bystrom, 1983, OOO
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 0.5% 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.
- Pineda and Kutler, 1972, OOO
Mesiodistal and buccolingual roentgenographic investigation of 7275 root canals. Apical Exit: 16.9% Lateral exit: 83% (6018 Canals) Apical major foramen diameter increases with age Most canals are curved and cone shaped.
- Shipper, 2004, JOE
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. Resilon seems to be a superior material.
- Lee, 1993, JOE Torabinejad was the third author
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.
- Glosson, 1995, JOE
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.
- Saunders and Saunders, 1994
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.
- Sundqvist, Johansson and Sjogren, 1989
Prevalence of Black-pigmented bacteroides species in root canal infections. Positive association between black-pigmented Bactroides species and apical abscess formation
- Tronstad, 1988,
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.
- Torabinejad and Ford 1997, JOE
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.
- Torabinejad and Hong, 1995, JOE
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.
- Spangberg, 1973, OOO
Biologic effects of dental materials. Toxicity and antimicrobial effect of endo antiseptics in vitro Toxic effects of NaOCl, CHI, iodine 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.
- Swanson and Madison, 1987, JOE
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. In vitro, artificial saliva.
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- Baumgartner, 1987, JOE
A Scanning Electron Microscopic (with nice pictures) 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
- Torabinejad, 1995, JOE
Bacterial leakage of mineral trioxide aggregate as a root-end filling material.
Fifty-six single-rooted extracted, human teeth with straight canals were used in this experiment
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.
- Koh and Torabinejad, 1998
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. Cellular toxicity. Cells remain flat, adhered and healthy.
- Schwartz, 2004, JOE
Post Placement and Restoration of Endodontically Treated Teeth. Retrievability easiness; metal>fiber>ceramic/zirconia 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
- Sundqvist, 1994,OOO
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 flora 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.
- Sundqvist, 1992, JOE
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
- Torabinejad and Higa, 1994, JOE
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
