WEEK 4 Flashcards
Outline G.V Blacks classification for carious lesions
CLASS I
- p/fs carious lesions
- occ surface of posterior teeth
- lingual surface of max incisors
CLASS II
- restos on proximal surfaces of post. teeth
- eg MOD, DO, MO
CLASS III
- restos on proximal surfaces of ant. teeth [not incl incisal edge]
CLASS IV
- Class III + incisal edge
CLASS V
- involves gingival 1/3 of all teeth, facial or lingual
- not incl p/fs
objectives of MID
- remin of early lesions
- reduction of cariogenic bacteria to eliminate risk or further demin
- minimal surgical intervention
- repair rather than replace
- disease control
list and describe the 7 steps to cavity preparation
- outline form
- access to caries
- reach sound tooth structure
- remove unsupported enamel
- retain restoration in tooth - resistance form
- shape and placement of prep should enable restoration to withstand fracture
- flat floor, slight rounding of internal line angles, sufficient dentin support - retention form
- shape form of prep - resists dislodgment from tipping or lifting forces - convenience form
- allows adequate observation, assessment and instrumentation - removal of carious dentin
- with spoon excavator or SSHP - finish enamel margins
- remove faults and walls smoothed - cavity debridement
- commonly with triplex air/water
- removal of debris from prep
explain the significance of a 90degree cavosurface margin
enamel rods usually perpendicular to enamel surface, with inner ends on sound dentin
the strongest enamel margin results in 90 degree angle
state the advantages of composite resin
- lower polymerisation shrinkage
- coefficient of thermal expansion similar to tooth structure
- high fracture/ water resistance
- high radiopacity
- colour match to tooth
- high bond strength to enamel/dentin
- high compressive strength
disadvantages of composite resin
- bacterial adhesion
- polymerisation shrinkage
- technique sensitive - tooth needs to be completely dry
- low tensile strength
describe polymerisation shrinkage and how to avoid it
shrinkage of material towards source of light
- amount of fillers in material will reduce amount of shrinkage [more viscous composite = more shrinkage]
reducing shrinkage
- incremental placement [place base like GIC to reduce filling dimension and act as shock absorber
- strong bonding agent
- good intensity light cure and hold close to restoration
explain c-factor and its relation to polymerisation shrinkage
configuration factor describes ratio of bonded to unbonded surface in restoration
influences polymerisation [high cf = associated w ^ shrinkage stress = debonding, marginal leakage, post op sens
eg class I preps have 5 bonded surfaces [walls + floors] and 1 unbonded [occ opening] = 5:1 C factor
- indicating high cf
CRs shrink as they polymerise, high cf means more of the CR is constrained by bonded surfaces = higher internal stress
describe etch and its function
37% phosphoric acid
creates microtags on enamel enabling a resin based material to bond micromechanically
describe bond and its function
bond = resin w less filler material
func = adheres composite to tooth surface, keeping restoration in place
describe dentine conditioner and its function
10% polyacrylic acid
removes smear layer [tooth prep debris spread on surface after prep] of dentine allowing material to bond chemically to tooth
dentin requires weaker shorter conditioning [to avoid harming collagen fibrils]
describe liner and its function
RMGIC [Vitrebond] used for cavity preps exceeding 2mm
- seals dentin tubules
- prevents thermal conductivity
- reduces post op sens
- protects pulp from toxins and stimulates repair
- reduces microleakages
- enables retention
vitrebond used under CR and amalgam [not to be placed directly on pulp]
- working time just under 3 mins
describe challenges with bonding composite resin to dentin compared to enamel
enamel has higher inorganic content [96%] compared to dentine [70%]
- dentin less mineralised and more porous
dentin tubules surround by collagen matrix
- makes surface less dense and heterogenous
smear layer
- during prep, smear layer forms on tooth = interferes with adhesion if not removed
hydrophilicity
- dentin more hydrophilic than enamel due to higher water content and dentinal fluid
- makes it harder for hydrophobic adhesives to bond effectively
briefly describe flowable resin and its properties
LESS filler than CR = more viscous = higher polymerisation shrinkage
lower compressive strength = not recommended for load bearing restorations
describe the sickle scaler and its function
- periodontal instrument - typically used on ant. teeth
- removes med-large supragingival calc depo
- triangular cross section not suitable for subgingival use
- two cutting edges/ working end
sickle scaler: describe how to find the working end on BOTH anterior and posterior teeth
inner cutting edge [closer to handle] = D surfaces
outer cutting edge ised on facial, lingual, mesial surfaces
ANTERIOR
1. work at midlines
2. position tip at midline in direction of work
3. tilt lower shank towards tooth to establish 70-80 degree angulation
4. roll instrument at line angles to main adaptation
POSTERIOR
1. position tip at distofacial line, with tip facing distally
2. tilt shank to enable 70-80 degree angulation and make distal strokes
3. tilt shank mesially at distofacial line and make strokes across facial surface
4. roll to maintain adaptation
describe GIC
- bonds chemically to enamel and dentin
- acts as reservoir for fluoride and promotes fluoride uptake
- available in capsules to form water based cement when mixed [undergoes acid/base reaction]
- lower compressive strength and wear resistance compared to CR
list advantages and disadventages of GIC
advantages
- fluoride content = makes GIC plaque resistant
- biocompatibility
- fluoride release aids remin
- ease of handling
disadvantages
- short working time
- brittle [cracks on dessication]
- poor resistance to acid attack
- inferior mechanical properties
- 24 hr setting time - needs coating agent
describe the GIC setting mechanism
- after powder/water mixed = acid dissolves on surface of glass particles
- in initial setting –> ca ions = released and react with polyacrylic acid = 3D cross linked structures
- setting reaction continues during next 24H [material matures by absorbing water], then final material strength is increased
list and describe the function of each adhesive system component
- etch = clean surface for bonding, removes smear layer - enabling primer to form hybrid layer
- primer = promotes adhesion to dentin - coupling agents between hydrophilic dentin and hydrophobic resin
- bond = provides better curing and seals dentin tubules - helps reduce shrinkage
describe the selective etch protocol
etching dentin frequently = post op sens
- universal adhesives [eg dentin conditioner] have eliminated the need to etch dentin
- now etch is typically used on enamel margins
list the indications for GIC
restorative material
fissue protectants
luting cement for crowns, bridges
pulp protection
ART
what are things that would be incl on a hard tissue chart
soft tx findings [I/E - E/O]
hard tx exam
periodontal exam findings [recession, pocket depths, furcation, mobility]
presence/ absence of teeth
caries
existing restorations and surface
prosthetics
defects
describe the role of water in GIC setting
GIC = 11-24% water when set
- evaporating too much air [w/ water] or too much water contamination during packing = can cause dissolution of matrix and material failure
- too much water uptake/ water loss = weak cement
- can be prevented by coating restoration surface immediately after it is placed eg vaseline
describe FOUR purposes for polishing a restoration
- longevity
- good marginal finishes and appropriate contours = less likely to fail - reduce plaque accumulation
- smoother restorations = less plaque aggregation = lower caries risk - aesthetics
- well polished restoration reflect light = make CR look more tooth like - patient comfort
- high/rough restos = uncomfortable and obstructs occlusion
list FOUR things than can be used for polishing a resto
- finishing burs
- finishing stones
- discs [soflex]
- polishing strips
briefly describe dental calculus
oral biofilm that has been mineraslied by calcium and phosphate minerals from saliva
- takes 10-20 days for biofilm –> mineralised calc
outline ideal toothbrush characteristics
small head for improved access
soft bristles
bylon/synthetic bristles
replaced every 2-3 mths
easy grasp
store in upright position in open air
list the fluoride conc for adult/childrens toothpaste
adult = 1200 ppm fluoride minimum
children = 500ppm fluoride
describe 5 toothbrushing techniques
- bass technique
- brush at 45 degree angle towards gingiva
- rotate brush againt gingival margin
- gentle, short vibrations side to side towards occ/incis surface - modified bass technique
- same as above, except circular motions instead of side to side - stillmans technique [gingival stimulation]
- angle toothbrush toward apex - partly on gingiva and tooth
- roll towards incisal edge - modified stillman
- as above + vibrate toothbrush whilst rolling - charters [aids interproximal / ortho cleaning]
- brush at 45d angle, bristles facing occlusal place - partly on tooth/gingiva
- roll towards incisal edge - fones [good for children]
- close teeth tgt
- brush upper and lower simultaneously w large circle strokes
- use smaller strokes for lingual surfaces
list indications for superfloss use
ideal for fixed prosthesis, ortho appliances, implant care, implant retained dentures
requires sit specific instruction on use
recommendations for interproximal cleaning in patients w dexterity issues
floss holders
- can be disposable or rethreaded
- improves dexterity
- however can be difficult to adapt to tooth contours
piksters/ interdental brushes if sizes suitable for site specific cleaning
describe alcohol in mouthrinses
isopropyl alcohol, ethyl alcohol, propanol
- optimal antimicrobial activity at 50-90%
- broad spectrum activity against bacteira, fungi, viruses
- in mouthwashes = used as solvent, preservative and antiseptic
- NOT RECOMMENDED FOR LONG TERM USE
- studies shows high conc [above 20%] associated with epithelial detachment, keratosis, ulceration, gingivitis, ^ risk of oral cancer
contraindications
- xerostomic pts [alcohol will further dry out mouth = discomfort, reduced saliva, ^ risk of caries
- sens/irritated mucosa [will irritate further]
- unsuitable for children due to risk of ingestion
describe chlorhexidine in mouthrinses
- broad spectrum bactericidal
- effective at 0.12-2% conc for plaque and gingivitis reduction
- binds w SLS and sodium fluoride [needs 30 min gap between two products or rinse w water before use
uses
- following SRP - 2 wks only - not when brushing
- following oral surgery
- acute gingivitis [not long term use]
- pre-procedural rinse for high risk pts
- irrigation of furcation and gingival trauma/inflammation sites
eg savacol, curasept
precautions
- can ^ supragingival calc
- staining on tooth, restos, tongue dorsum
- cause taste pervesion/ burning
- desquamation
- not rec for children
describe benzydamine hydrochloride in mouthrinses
- NSAID
- 0.15-1% conc
- added to some CHX rinses
- LA and analgesic properties
- reduces severity/duration of radiation induced mucositis, xerostomia, ulcerations
describe hydrogen peroxide in mouthrinses
relief for
- minor gingivitis [due to oxygenating cleansing action]
- soreness caused by dentues, ortho appliances or post op procedures
- for pts w physical / intellectual impairement which limits their OH
- reduces gingival inflammation before fixed prosthodontic
describe the universal curette
- periodontal instrument - removes small-med calc depos
- can be used ant.post.sub.supra.
- rounded back and toe
- semi circle cross section
- two cutting edges/ working end
- 70-80d angulation
cutting edges
- inner edge = distal surfaces
- outer = mesial, facial, lingual
on posterior teeth
- begin at DF line [toe points distally]
- lower handle and insert below gingiva
on anterior teeth
- only OUTER cutting edge used on ant surfaces
- start at midline
then horizontal strokes
what do dental records include and why are they important
- efficient and complete delivery of dental care
- high quality comprehensive care
- evaluation of care [quality assurance programs, future reviews, patient advice]
what is incl
- med hx
- notes by provider, other clinicians, staff
- consent forms
- radiographs, measurements
- tx plans
- digital records
- documents, correspondance
- estimates/quotes
outline the requirements for record retention
kept for at least 7 years after the entry
for minors, kept until individual = 25yo
describe denture care advice
clean twice daily over basin filled w water [will avoid breakage if dropped]
remove plaque/debris from gums w wet face washer
remove in evening and store in dry container
avoid using
- abrasive cleaning agents or brushes
- hot or boiling water [can cause warping]
- detergents, bleaches, methylated spirits, strong chemicals
outline the four pillars of dental ethics
- autonomy [self-determination]
- pt has right to informed decision w/o coercion
- informed consent - justice
- fairness for all
- considers pts needs incl distribution of resources - beneficence
- acting in pt best interest - non maleficence
- avoidance for inflicting harm
- ensuring practice within scope of knowledge and skills
