Wiggs - Old version Flashcards
Name the 3 basic parts of a hand instrument
- handle
- shaft/shank
- Working end
What are the 3 types of working ends of a hand instrument?
- point
- Blade
- Nib
What are the advantages of either a solid or hollow handle on a hand instrument?
Solid has a firmer grip
Hollow has better tactile sense
Name 3 types of dental mirrors
- plane flat surface (won’t scratch, creates double images)
- Flat surface (scratch, no distortion)
- Concave surface (magnified image, distorted)
Name 3 methods of grasping a hand instrument and when to use and why
- Palm grasp: like carving with a knife. Limited range of motion and tactile sense
- Palm and thumb grasp: instrument and sharpen instruments. Finger knuckles act as fulcrum
- Modified pen grasp: most commonly used. Excellent control, stabilization, range of motion and tactile sense
Define instrument adaptation
the way in which an instrument contacts the intended surface
What type of periodontal probe is this?
Williams probe (1,2,3,5,7,8,9,10mm)
What type of periodontal probe is this?
Marquis probe (3,6,9,12mm)
What type of periodontal probe is this?
Michigan-o Probe (3, 6, 8mm)
What type of probe is this?
Nabor’s No 2 probe (used to explore furcations)
What are the 3 types of periodontal explorers and how is each utilized?
- Hu-Friedy No 3A - long gentle curve to examine furcations for calculus or caries
- No. 17 - detection of sub gingival calculus an restorative margins
- No. 23 - classic shepherds hook, used for detects of lesions above the gingival margin
What type of periodontal explorer is this?
Hu-Friedy 3A
long gentle curve to examine furcations for calculus or caries
What type of periodontal explorer is this?
No 17
detection of SUBgingival calculus an restorative margins
What type of periodontal explorer is this?
No 23 (Shepherds hook)
detection of tooth caries or lesions ABOVE the gingival margin
What is a sickle scaler and what is it used for?
Triangular in cross section, SHARP back, 2 straight cutting edges and pointed tip
Curved and straight (Jacquette)
Removal of SUPRAgingival calculus
What is the instrument of choice for light sub gingival calculus removal, root planing, and gingival/subgingival curettage
The curette
2 cutting edges and a ROUNDED back and toe
Introduced into the sulcus and a pull motion is used to remove calculus or debride soft tissue
Name each type of curette
- Universal curettes
- Standard Gracey Curette (Pull)
- Gracey Push curette
- Turgeon modified grace curette
What is a hoe used for? What is the blade angle?
removal of large deposits of supra gingival calculus
99-100 deg (no pointed tip)
Pull stroke
What is a chisel used for? What is the blade angle?
large supra gingival calculus
limited use in vet med
Used in a push stroke
What is the most commonly used and only natural stone for sharpening dental instruments?
Arkansas stone - produces a smooth finish due to its fine grit
What are the two tests to examine blade sharpness?
- Shave test: sharp blade with bite into the acrylic stick or shave off a thing slice
- Visual test: sharp blades DO NOT reflect light
Explain Dr. Black’s numbering system for instruments with blades. What doe the numbers 10-7-14 indicate?
- The 1st number (10) is the width of the blade in tenths of a millimeter (10=1.0mm)
- second number represents the blade length in mm (7mm)
- the third number designates the angle the blade forms to the long axis of the handle or shaft in degrees centigrade (14deg C)
- If a 4th number is shown between numbers 1 and 2, and represents the angle of the cutting edge of the blade to the long axis of the handle.
What wave lengths are produced by light curing guns?
400-450nm (visible or near-red range)
Match the type of electrosurgical current with its uses and indications:
A. 3
B. 1
C. 4
D. 2
E. 1
F. 4
G. 2
H. 3
True or False: When using electrosurgery/radiosurgery units, any high-frequency electrical current >10,000 hertz (10kHz) can be dangerous to the patient.
FALSE
High frequencies of 2-4million hertz (2-4MHz) are needed. Anything LESS than 10,000 hertz can be dangerous to the patient
Ultrasonic scalers generally function at ______ kHz and work by what 2 basic principles?
> 20kHz
- Mechanical kick: calculus removal)
- Cavitation: water spray to clean surface
High speed hand pieces operate between _________ and _______ rpm
100,000 and 800,000 rpm
Low speed handpicks operate at ________ rpm
<20,000 rpm
What is the only bur material that holds up well to enamel when used with high speed and maintains its sharpness when doing so?
Carbide steel
What is the most commonly used chelating agent used in endodontic procedures? What does chelation mean?
ethylenediaminetetraacetic acid (EDTA) - RC Prep is a common example
Softening of inorganic structures
What are the ingredients in RC Prep and what is their function in regards to root canal prep?
EDTA: chelation/softening of inorganic structures
Lubrication
Urea Peroxidase: aids in dissolution of organic debris and provides antibacterial activity
What is the purpose of 5.25% sodium hypochlorite in root canal preparation?
Dissolves organic debris
Why can’t composites be used directly over eugenol products (ZOE)?
Interferes with composite curing
- glass ionomer liner, MTA or calcium hydroxide liner, etc. is recommended before application,
especially when the vital tissue is exposed/nearly exposed
What are the 2 types of gutta-percha points or cones?
Type 1: standard points that approximate file sizes
Type 2: conventional cones known as accessory cones that are more tapered and used for lateral compaction
How to acrylic plastics work in dentistry?
Methyl methacrylate is mixed from a powder (polymer) and liquid (monomer).
Benzoyl peroxide is used as an initiator and when activated by heat or an amine activator, results in polymerization
What are the 2 types of acrylic?
- Cold cure acrylic: self or auto curing acrylic. An amine in the monomer activates the initiator
- Heat cured acrylic: the activator of the initiator is heat
Composite restoratives are typically composed of an organic polymer matrix of high molecular weight, usually _____________ resin with or without fillers
bisphenol A-glycidyl methacrylate (BIS-GMA)
What are unfilled resins used for?
Coat or line the areas to be filled
Help decrease micro leakage that could others lead to shrinkage, lack of bonding and sensitivity if vital teeth are involved.
In regards to filled resins, the inorganic filler portion is typically ____% of the material by weight and are primarily in the forms of what 3 particle types?
70-80%
Crystal quartz
Silica
Lithium
In Microfilm composites, the particle size is ______ and is usually a colloidal silica. The filler content may be only 35-50% which will have what affect on the coefficient of thermal expansion and shrinkage?
<0.04um
Increase coefficient of thermal expansion and increased shrinkage during polymerization
Conventional fill (macro fill) composites have a particle size of ___ - ____ um
20-35um
Hybrid fill composites have large and small particle sizes with an average of _______um
1.5um
Intermediate fill composites have a particle size of _____-____um
1-5um
More esthetic finish than macro fill and sturdier than microfilm
Glass ionomers do not bear stress or wear well and are useful in non-occlusal areas and can be useful in class ____ restorations
Class V restorations
Name 3 advantages and 2 disadvantages of glass ionomers
Advantages:
1. Chemical bond to enamel and dentin
2. Slowly release fluoride over time (negating need for cavity liners in most cases)
3. Coefficient of thermal expansion closely approximates that of the tooth so a tight marginal seal is maintained.
Disadvantage
1. Technique sensitive (long setting time, moisture restrictions)
2. Do not handle stress and wear well.
What is the purpose of a varnish? What is a contraindication for its use?
Varnish protects by keeping chemical irritants away from the pulp and provides marginal seals.
They should not be used under composites because the varnish solvent may soften the resin and the residual monomer may dissolve the varnish.
What is the purpose of using CaOH when placed adjacent to pulp tissue (liner)?
To induce osteoblasts to form dentin and form a dentinal bridge
Define the 3 basic types of tooth development (Monophydont, Polyphyodont, and Diphyodont)
Monophyodont: 1 set of teeth throughout life (rats and dolphins)
Polyphyodont: Many sets of teeth that are continually replaced (sharks)
Diphyodont: Two sets of teeth, deciduous and permanent (domesticated animals and humans)
Define successional teeth
permanent teeth that replace deciduous teeth (incisors, canines, premolars)
Define the two basic categories of tooth shape (Homodont and Heterodont)
Homodont: all teeth are the same general shape or type (fish, reptiles and sharks)
Heterodont: several types of teeth (dog and cat)
Define the three common types of tooth anchorage (thecodont, acrodont, pleurodont)
Thecodont: teeth firmly set in sockets using gomphosis (fibrous joint)
Acrodont: no true root structure or socket, ankylosed to bone
Pleurodont: teeth grow from pockets inside the jaw
Define the two basic tooth crown types (brachyodont and hypsodont - radicular and aradicular)
Brachyodont: short crown:root ratio (dogs, cats, primates)
Hypsodont: longer crown with short roots, as the crown wears down submerged crown erupts (horses, cows)
Radicular Hypsodont: Closed roots, continually erupting teeth (horses, cow)
Aradicular Hypsodont: open roots, continually growing teeth (rats)
Define the terms for crown cusp of cheek teeth (secodont, bunodont)
Secodont: cheek teeth have cutting tubercles or cusps for cutting or shearing (carnassial teeth)
Bunodont: Low rounded cusps on occlusal surface for crushing or grinding. (dog/cat molars)
Define anisognathous
unequal jaws, the mandibular molar occlusal zone is narrower than the maxillary counterpart (cat, dog, horse, cow etc)
Around the 25th day of development, rudimentary signs of t tooth development occur when the embryonic oral (strafed squamous) epithelium begins to thicken. This thickening is known as the __________
Dental lamina
The _________ arises from a series of invaginations in the dental lamina
Enamel organ
The dental papilla and dental sac originate from ________
mesoderm
The oral epithelium, dental lamina, and the enamel organ originate from the outer embryonic germ layer known as _________
Ectoderm
Match the structure with its tissue layer of origin
- Dental Papilla - Mesoderm
- Oral Epithelium - Ectoderm
- Enamel Organ - Ectoderm
- Dental Sac - Mesoderm
- Dental Lamina Ectoderm
What stage of enamel organ development is represented here?
Bud stage -
What stage of enamel organ development is represented here? What are the 3 components of the enamel organ at this stage?
Cap stage
- Outer enamel epithelium (OEE): PROTECTS entire organ
- Inner enamel epithelium (IEE): FORMS ENAMEL by ameloblasts TALLER cells
- Stellate reticulum (SR): CUSHION for IEE and fluid passage to cells
What stage of enamel organ development is represented here? What is the 4th layer that emerges during this stage?
Bell Stage
The stratum intermedium emerges btw the IEE and the stellate reticulum
A __________ occurs when the palatal plates of the maxillary process fails to fuse with the nasal septum (usually between the second and third incisor).
Cleft Palate
When migration fails to occur between the maxillary process and the medial nasal process it results in a __________
Cleft Lip
Enamel is produced by the _________ which is derived from __________
Enamel organ
Ectoderm
Dentin and pulp develop from the _______ which is derived from ________
Dental papilla
Mesoderm
What is the composition of Enamel? What % inorganic material is it made of?
96% Inorganic - hydroxyapatite
4% organic - water and fiber
The basic building block of enamel is the enamel rod - each rod is composed of what 2 parts? What is each part made of?
- Rod core - hydroxyapatite
- Rod sheath - organic fibrous tissue
During the maturation stage of calcification, the crystals grow in size, becoming tightly packed together within the enamel rod. Should the crystals fail to grow to full size, the rods will be poorly calcified and have less than 96% inorganic composition. What is that condition called?
Hypocalcification
The ________ are darker lines in the enamel that radiate out in a curve from the DEJ. These are areas of slight variation in the crystal content of the rods
Striae or stripes of Retzius
As enamel is produced by the ameloblasts, a change occurs in the enamel organ. The ameloblasts gradually compress the 2 middle layers of the organ, the stratum intermedium and stellate reticulum. The middle layers are lost and the ameloblasts make contact with the OEE. This activates the final 2 functions of the amelobasts, what are these functions?
- Formation of Nasmyths membrane (primary enamel cuticle) which is a protective layer laid down on top of enamel
- Formation of the reduced enamel epithelium by merging of the ameloblasts and the OEE. The reduced enamel epithelium is produced the epithelial attachment
What is the function of the epithelial attachment?
Hold the gingiva and tooth together at the bottom of the gingival sulcus.
Enamel that has normal density but is thinner than normal is called _______ and enamel that has areas that are poorly mineralized resulting in yellow or brown spots is called _________
Enamel hypoplasia or hypo plastic enamel
Enamel hypo calcification
What is the composition of Dentin? What percent inorganic material is it?
70% inorganic hydroxyapatite crystals
30% organic (collagen fibers, mucopolysaccharide and water)
What are the 3 distinct structures of dentin?
- Dentinal tubules
- Odontoblastic process (Tomes fiber)
- Peritubular dentin
_________ dentin develops first, before tooth eruption, begin development at the same time that root formation is nearing completion. ______ dentin develops after tooth eruption
Primary dentin
Secondary dentin
What are the 5 variations of dentin types?
- Reparative dentin (tertiary dentin)
- Interglobular dentin - dentin found next to DEF, hypo calcified
- Granular layer of Tomes - dentin next to CDJ, hypo calcified
- Dead Tract dentin - dentin with empty tubules
- Sclerotic Dentin (transparent dentin), tubules filled with dentinal matrix after trauma
The hertwigs epithelial root sheath cells that move away from the dentin, but fail to dissolve, become
entrapped in the PDL and are referred to as ____________.
Epithelial rests of Malassez
What are the functions of the Hertwig’s epithelial root sheath?
- regulation and maintenance of PDL
- Prevention of root resorption and ankylosis
- Maintenance of PDL homeostasis
- Induction of acellular cementum formation
- Stem cells
When epithelial root sheath cells fail to dissolve and remain in contact with the dentin they typically convert to _________. These will secrete enamel on the roots, forming _________
Ameloblasts
Enamel Pearls
What is the composition of Cementum?
45-50% inorganic hydroxyapatite and 50-55% organic materials and water
Acellular cementum makes up what portion of the tooth? What about Cellular cementum?
Cervical 1/2- 2/3rds is acellular
Apical 1/3 is cellular cementum
______ fibers connect the cementum of the tooth to alveolar bone
Sharpey’s
What are the 3 stages of tooth eruption?
Pre-eruption: starts with crown development and the formation of the dental lamina
Pre functional eruption: begins with the onset of root development
Post eruption: when the teeth move into actual occlusion—considered to continue until tooth
loss or death
The three protrusions along the incisal edge formed by the developmental grooves are called ________
Mamelon
The fourth lobe on the lingual tooth surface forming the majority of the tooth bulk is called the ________
Cingulum
T or F: The epithelium lining the sulcus and the col is among the very few ares of mitigatory gingiva that are parakeratinized
F - these areas are non-keratinized
At the bottom of the sulcus the ________, which directly attaches the gingiva to the tooth.
Junctional epithelium
Increasing thickness of __________ cementum over time due to occlusal stresses is called _________. Common in cats and can be excessive forming bulbous apex increasing difficulty for extractions.
Cellular cementum (found at the apical 1/3 of the root)
Hypercementosis
The temporalis muscle is the largest and most powerful muscle of mastication. It occupies the __________ fossa and extends to the _________ of the mandible
Temporal fossa
Coronoid process of the mandible
The masseter muscle arises from the ________ and inserts on the _______ of the mandible
Zygomatic arch
Lateral ramus of the mandible
