Top 40 Flashcards
- kakehashi, 1965
The effects of surgical exposures of dental pulps in germ-free and conventional laboratory rats.
Presence or absence of microorganisms is the major determination in the formation of dentinal bridging and pulp healing.
- Kutler, 1955
Microscopic investigation of root apexes.
Examination of 268 teeth.
Foramen is off center of apex in 80% of time due to cementum deposition as we age.
Distance from apex to center of foramen = .5 mm
Average foramen diameter = .5 mm
Foramen diameter incenses due to cementum deposition.
- Torneck, 1966
Reaction of rat connective tissues to polyethylene tube implants. Part I, Phase I and II
To Investigate the influence of unfilled space and other local factors associated with endodontic repair on the connective tissue healing.
Sterile open tubes were surgically placed on the backs of rats for 60 days and then examined.
Phase I; tubes open at both ends
Phase II; tubes sealed at one end.
Tubes were surrounded by a noninflammed connective tissue capsule.
Diameter and length of tube did not have a major effect on the tissue reaction.
Proves that an underfilled RCS that has been properly cleaned and dissinfected will result in healing of the surrounding periapical areas.
This disproves the hollow tube theory.
- Torneck, 1967
Reaction of rat connective tissue to polyethylene tube implants. Part II, Phase III and IV
Phase III; Tubes sealed on one end containing autoclaved muscle tissue were placed in back of rats.
Mostly mild inflammation was observed with few cases of moderate to severe inflammation with granulation tissue formation and pus at the open end of the tube.
Phase IV; Tubes were sealed on one end and contained muscle tissue inoculated with gram-negative cocci organisms.
Moderate to intense inflammation with abscess formation.
Combination of tissue and microorganisms offered the poorest prognosis for repair.
- Schilder, 1974
Mechanical objectives
Cleaning and shaping the root canal.
- Continuos taper from apex to coronal portion.
- Cross sectional area; narrower apically, wider coronallly.
- Maintain original shape of canal; flow
- Maintain original position of AF.
- Apical enlargement as small as practical.
- Schilder, 1974
Biological objectives
- Confine instruments to the root canals
- Do not force necrotic material beyond the apex
- Remove all tissue debris from RCS
- Complete cleaning and shaping of single canals in one visit.
- Create sufficient space for intracanal medications and exudate reception.
- Bender and Seltzer
Radiographic and direct observation of experimental lesions in bone.
Artificial lesions made in bone and radiographed.
Extensive disease of bone may be present even when there is no evidence of it on the radiographs.
Lesions in cancellous bone cannot be detected on radiographs- The apparent cancellous destruction that is seen on radiographs is really an erosion of the innermost surface of the bone cortex at the junction area between cortex and cancellous bone
- Goldman, 1972
Endodontic success- Who is reading the radiograph.
253 cases reviewed radiographically by six examiners.
Agreement was reached in less than half the cases. 48%
upper molars had the greatest percentage of disagreement.
- Sundqvist, 1976
Bacteriological studies of necrotic dental pulps.
27 patients with non-vital pulps and intact pulp chambers.
No PARL = no bacteria
increase in bacteria= More pain, signs and Symptoms and PARL
Strains of bacteria influence the size of the PA lesion.
Dominance by obligate anaerobic bacteria.
- Brannstrom and Astrom, 1972
The hydrodynamics of the dentine; its possible relationship to dentinal pain.
Pain is produced by the RAPID displacement of tubular contents at the pulpo-dentinal border, and pulp acts as mechanoreceptor.
Outward movement: Air blast, drilling, cold
Inward movement: Heat caused delayed pain due to slower movement of fluid.
- Brannstrom, 1986
The Hydrodynamic theory of dentinal pain; sensation in preparations, caries, and the dentinal crack syndrome
Main cause of dentinal pain is caused by rapid outward flow of fluid caused by capillary forces.
Hyperosmotic stimulation caused the same effect.
Heat applied to intact tooth activates C-fibers while heat applied to exposed dentin activates
A-fibers
- Harrison and Jurosky, 1991
the incisional wound
Wound healing in the tissues of the periodontium following periradicular surgery. The incisional wound
Surgery performed on rhesus monkeys and healing evaluated under light microscope.
Submarginal rectangular incisions showed less predictable healing pattern.
24 hrs. PMNs were predominant
48-72 hrs. Macrophages were predominant.
- Harrison and Jurosky, 1991
The Dissectional wound
Wound Healing in the Tissues of the Periodontium following Periradicular Surgery, II. The Dissectional Wound
Dissectional wounding results from the elevation of a mucoperiosteal flap from cortical bone during flap reflection.
Report on the response of the mucoperiosteal and osseous tissues to blunt dissection.
Slower healing than incisional wound
Granulation tissue replaces fibrin clot in the wound site as early as 4 days after surgery.
Formation of type III collagen at the wound site at 2 days.
Granulation tissue replaced by fibrous connective tissue by 14 days.
Osteoclastic and osteoblastic activity noted at surface of crestal bone at 14 and 28 days.
Healing is essentially complete by the 14th day with remodeling and maturation of soft and osseous tissues continuing through the 28th day.
- Roane, 1985
the Balanced force concept for instrumentation of curved canals.
The balanced force technique is accomplished by placing file into the with inward pressure, rotating the file no more than 180 degrees clockwise rotation to engage dentin, to prevent over insertion of the apical portion into dentin and possible instrument separation, followed by a cutting motion, counterclockwise rotation of 120 degrees . This action completely enlarges the canal to the file diameter. The technique is repeated until the desired working length is accomplished or the file is filled with debris. Balanced force concept provides superior operator control and ability to increase the enlargement of curved canal.
- Schilder,
Filling root canals in three dimensions.
Vertical condensation:
1- Three dimensional obturation
2- Lateral canals filling is included in this obturation technique
3- Dimensional stability
4- Greatest GP density apically
Overextension refers to an obturation that lacks a proper apical seal leading to the extension of the either a silver cone or a gutta percha cone.
-Overfilling, on the other hand, means that the canal was fully obturated and sealed apically but a surplus of the filling material got intruded beyond the foramen.
