4th Year #1 Flashcards
(409 cards)
1
Q
Can you take a radiograph for a pregnant patient?
A
YesDose from one periapical is approx 0.001 mGy and from an OPT 0.1mGy and maximum dose thought to cause concern is 200mGy (background 50mGy per year and this is possibly higher in Aberdeen!) remember a milligray ( mG or mGy is the absorbed dose)However, this is an emotive subject and the risks vs the benefits must be discussed with the patient. It is worth mentioning that having 0.001-0.1mGy still carries a risk of less that 1 in 1,000,000 risk of childhood cancer (1). Some prospective mothers might not want to take that risk. Risk less before 10 weeks and after 27 weeks but because of the “ emotive nature of dental radiography during pregnancy, the patient could be given the option of delaying the radiography”
2
Q
Why should you avoid Felypressin?
A
it can cause uterine contractions
3
Q
Which antibiotics are safe and dangerous for pregnant patients?
A
Yes, it is safe to prescribe penicillins Avoid: - metronidazole- erythromycin- tetracycline- doxycycline
4
Q
What pain relief to recommend to pregnant patients?
A
Paracetamol is safeAvoid:- NSAIDs- Aspirin- Dihydocodiene- Codiene
5
Q
What symptoms can a pregnant patient experience at 8 week?
A
Blood pressure drops:- fainting riskEmotional changesIncreased urinationVominitingAnaemia
6
Q
What is Dalteparin?
A
a low molecular weight heparin anticoagulantSubcut
7
Q
Is amalgam safe for pregnant patients?
A
No, it is best avoided as Mercury can crossthe placenta and has been detected in breast milkA temporary restoration should be placed insteadRemoval of an amalgam filling can carried out under rubber dam and high volume suction
8
Q
Should Duraphat be precribed for a pregnant patient? and what alternatives are there?
A
No, due o its alcohol contentNor 5,000ppm flouire toothpastes as the effects of high fluoride are unknown2,800ppm is deemed safe but must be spat out after brushingFluoirde MW of 225ppm or 900ppmFor lactating/breastfeeding
9
Q
Why to double check medical history when dealing with pregnant patients?
A
They may not know they are pregnant, or don’t feel like it is important to tell youCheck history generally
10
Q
Check for pregnancy gingivitis?
A
hormonal changes can excaerbate pre exisiting plaque induced gingivitisPossibly gestational diabetes
11
Q
Symptoms of first trimester?
A
increase in oestrogen and progesterone seems to coincide with increase in gingival inflammation
12
Q
Describe how hyperplasia of the gingivae looks and is caused?
A
Hyperplasia of the gingivae is caused by marked proliferation of capillaries and minimal proliferation of fibroblastsClinically it appears as dark red/purple papillae which are fragile, bleed easily. False pocketing and stagnation also may be a problem
13
Q
Describe how a pregnancy epulis occurs? and how it looks?
A
Caused by inflammatory response to local irritation which is modified by hormonal changes- 3rd month of pregMushroom like flattened spherical mass – sessile pedunculated base, protrudes from the gingival margin, in the interproximal space, red to dark blue in colour, bleeds easily with minimum trauma, painless unless it interferes with the occlusion
14
Q
How to treat a pregnancy epulis?
A
Treatment – same as for pregnancy. induced gingivitis plus you might consider biopsy if it does not resolve after the birth of the baby.The use of Chlorhexidine mouthwash is not contraindicated but always remember to warn about taste alterations and staining with prolonged use.
15
Q
Which antifingals are safe and dangerous during pregnancy?
A
Amphotericin is safe and nystatin but Avoid:- miconazole- fluconazole(can transfer to foetus or risk malformations)
16
Q
Is there a link between periodontal disease and preterm/low birth weight babies?
A
Preterm= pre-37weeks Low birth weight < 2,500 g or 5.5lbsIncidence – over 4 million die within first 4 weeksRisk factors – young maternal age, drug alcohol and tobacco abuseMaternal stress, genetics, genito-urinary tract infectionMultiple or assisted pregnanciesResearch into interventions is not conclusivePeriodontium = reservoir of gm –ve bac, host response elevated levels of chemical mediators, premature labourNo conclusive evidence
17
Q
What is hyperemis Gravidarum?
A
continued vomitingusually during the first trimester but can be throughout. causing dehydration (dry mouth), weight loss, electrolyte imbalance and hospitalisationdon’t brush after vomiting
18
Q
How to treat a patient with erosion due to pregnancy vomiting?
A
Dress teeth, protecting the exposed enamelA dentine bonding agent ( ie Seal and Protect ) will aid protectionConsider Delaying RCT and radiographs until after birth if possibleWe should consider taking study models to observe wear, gag reflex is exaggerated due to obstruction of oesophagus
19
Q
How to deal with vena cava compression?
A
posture, take care when lying the patient flat, consider the left lateral tilt to relieve the compression on the blood vessel, use cushion or use a rolled up towel.
20
Q
Acyclovir for cold sores?
A
Minimal absorption to the foetus, but shedding at term may lead to HSV transfer to the baby
21
Q
When is the best time for dental treatment during pregnancy?
A
Research and evidence suggests that dental care during pregnancy is safe, effective and recommended. ( best time is second trimester)
22
Q
Name the 3 main tyoes of inherited coagulation disorders?
A
Haemophilia AHaemophilia Bvon Willebrand’s disease
23
Q
Describe Haem A?
A
Factor VIIIX-linkedfemale carries can have mild bleeding tendency
24
Q
Describe Haem B
A
Factor IX defX-linked
25
Describe vWD?
Factor VIII def and reduced platelet adhesionDominant inhertance1 in 100
26
Describe symptoms of haemophilia?
PEOPLE WITH SEVERE HAEMOPHILIA HAVE FREQUENT BLEEDS INTO MUSCLE AND WEIGHT BEARING JOINTSMODERATE SUFFERES HAVE A FEW SPONTANEOUS BLEEDS AND IN MILD HAEMOPHILIA THE BLEEDS USUALLY OCCUR AFTER TRAUMA, SURGERY OR DENTAL EXTRACTIONS.
27
Where do we treat patinets with CBD (congenital bleeding disorders)?
#NAME?
28
What are the management strategies for CBD?
Some dental procedures don’t require augmentation of coagulation factor levels.Coagulation factor replacement therapyRelease of endogenous Factor stores using desmopressin (DDAVP)Improving clot stability by antifibrinolytic drugs, e.g. tranexamic acid .Local Haemostatic measuresLIASON WITH A HAEMATOLOGIST
29
Wghat is the definition of DDAVP?
DesmopressinA SYNTHETIC HORMONE, IS A DRUG WHICH IS SOMETIMES PRESCRIBED TO STIMULATE THE RELEASE OF ENDOGENOUS FACTOR STORES.
30
Describe transexamic acid?
MANAGEMENT STRATEGY TO IMPROVE CLOT STABILITY
31
What is Haem A and B MoA?
Normal bleeding time and INR but prolonged activated partial thromboplastin time (APTT)Replacement of the deficient clotting factors - porcine or recombinant by IV infusion Severe cases : daily injections15-25% people develop inhibitors or antibodies with repeated use.
32
Describe the factor replacements and how they should be used?
FACTOR VIII HAS A HALF LIFE OF ONLY 10-12 HOURS AND DENTAL TREATMENT HAS TO BE CARRIED OUT ON DAY OF COVER ALTHOUGH IT IS PREFERABLE, IT IS RARELY POSSIBLE FOR EXTENSIVE DENTAL TREATMENT TO BE COMPLETED IN ONE VISIT, HOWEVER TREATMENT SHOULD BE ORGANISED TO MINIMISE THE NUMBER OF FACTOR REPLACEMENT SESSIONS AND THUS THE LIKELIHOOD OF ANTIBODY DEVELOPMENTFACTOR IX HAS A LONGER HALF LIFE, ALLOWING DENTAL TREATMENT TO BE CARRIED OUT ON CONSECUTIVE DAYS UNDER A SINGLE DOSE OF REPLACEMENT THERAPY
33
Describe vWD MoA?
Extended bleeding time due to poor platelet function and low levels of circulating vWF and ristocetin co-factor. 75% have mild or Type 1 vWDUsually treated with synthetic hormone desmopressin (DDAVP)Infused IV over 20 minutes at Haemophilia CentreCan also be self-administered as high strength nasal sprayMore severe types require factor replacement therapy derived from human plasma. Ristocetin co factor
34
Post OP adivce for CBD?
Severe cases requiring extractions and interventive surgery are usually treated in a safer setting or hospital environment Some patients are asked to return to the hospital for monitoring. Tranexamic Acid (TA) Usually administered in tablet form 1g three times a day up to10 days Also available as a syrup or mouthwash in a dental situation TAILORED WRITTEN AND VERBAL POST-OPERATIVE ADVICE WITH CONTACT TELEPHONE INFORMATION AND AVOIDANCE OF NSAIDS
35
General principles for factor replacement?
Dental procedures should be performed as close to the time of administration of Factor concentrate as possible.Factor cover may be prescribed as prophylaxis or on demand.Expensive - dental treatment should be organised to minimise exposure to Factor replacement therapy.
36
Blood transfusions before 1986?
Non inactivated replacement factor concentrates from pooled human blood until 1986 when effective heat treatment was introduced.Risk factor of HIV and vCJD prior 199970% patients with haemophilia have presence of HCVRecombinant (non human derived) factor concentrates in early 1990’s removed the risk of viral or prion transmission
37
Name the general measure to reduce bl;eding risk?
Minimal traumaLA with vasoconstrictorhaemostatic agents in socketsSutures (resorbable)Post OP adviceAvoid NSAIDs
38
How to manage a patient needing emergency treatment with CBD?
Acute pulpitis - pain can usually be controlled by removing pulp from tooth. Temporary dressing until planned extractionDental abscess with facial swelling. Antibiotics only if local spread or systemic infection. Seek advice from haemophilia centreFractured teeth - normal management +/- cover if significant bleeding soft tissues
39
Drugss to avoid with CBD?
AspirinNSAIDs
40
CBD considerations for soft tissues?
chlorhex MWparaffin wax to avoid adherence to mucosa
41
CBD considerations for resto?
nil
42
CBD considerations for subging resto?
haemostatic agents - retration cord or transexamic acid
43
CBD considerations for endo?
sodium hypochlorite irrigation and CaOH paste for bleeding control
44
CBD considerations for rubber dam?
avoid trauma
45
CBD considerations for high speed aspiration
avoid trauma
46
CBD considerations for denture?
care with fittingsoft lining (if needed)
47
CBD considerations for ortho?
prevention and oral hygiene advicewax to stop trauma
48
CBD considerations for routine scaling?
Transexamic acid MW
49
CBD considerations for perio surgery?
good oral hygienefactor cover
50
Mild causes of red eyeness?
Conjunctivitis• Subconjunctivalhaemorrhage• Dry eyes• Episcleritis
51
Moderate acuses of red eyeness?
• Corneal abrasion• Corneal foreign body• Iritis (uveitis)• Scleritis• Facial nerve palsy
52
Severe causes of red eyeness?
• Corneal ulcer(keratitis)• Penetrating injury• Chemical injury• Acute glaucoma• Orbital cellulitis
53
Questions to ask when assessing a red eye?
1 eye or 2 eyes affected? Duration of symptoms? Discharge? Do you wear contact lenses? History of injuries Previous episodes of something similar? What treatments have you tried? Systemically unwell? How does it feel?Pain?Irritated/scratchy/”sand in my eye”Foreign body sensationPhotophobia – pain in presence oflight (think cornea!) Has vision been affected? Appearance of the pupilRound?Reactive to light compared to theother side?
54
Which eye conditions cause pain?
• Corneal ulcer(keratitis)• Penetrating injury• Chemical injury• Acute glaucoma• Orbital cellulitis• Corneal abrasion• Corneal foreignbody• Iritis (uveitis)• Scleritis
55
Which eye conditions affect vision?
Conjunctivitis• Dry eyesCorneal abrasionIritis (uveitis)Facial nerve palsyCorneal ulcer(keratitis)• Penetrating injury• Chemical injury• Acute glaucoma• Orbital cellulitis
56
Which eye conditions chnage the apperance of the pupils?
Iritis (uveitis)Penetrating injuryAcute glaucoma• Orbital cellulitis
57
Describe causes of facial nerve palsy?
Inferior alveolar nerve block• Parotidectomy
58
How to manage facial nerve palsy?
Tape eye closed• Generous lubrication• Optometrist• Safety net advice
59
Describe causes of corneal ulcer?
contact lensesvery light sensitiveurgent <24 hrsforeign bodies - high speed mechanisms
60
Describe causes of subconjunctival haemorrhage?
asymptomaticonly cancer in traumarelated to HT and anticogulants
61
Name the 2 forms of conjunctivtis?
bacterialViral
62
Describe bacterial conjunctivitis?
Sticky, purulent discharge• Bilateral, sequential• Gritty, uncomfortable
63
Describe viral conjunctivitis?
Watery, “streaming”• Bilateral• Pre-auricular lymphadenopathy
64
Describe a good history taking for vision loss?
Describe what they can see/not see Blurry Distortion Flashing lights/floaters? Areas of “missing vision” Painful? Painless? Speed of onset Gradual Sudden Other systemic symptoms?
65
Name possible causes of vision loss?
Cataract ARMD Glaucoma Retinal detachment Giant cell arteritis
66
Describe symptoms of cataract?
Common(est?) operation in the world The lens does not age well! Leading cause of blindness Low-middle income countries Gradual, painless, hazy/misty vision, near/total blindness Phacoemulsification surgery Quick, safe, painless, no sutures Very happy patients!
67
Describesymptoms of age related macular degeneration?
Age-related macular degeneration Only central vision affected Blurred, distorted, holes/gaps, “it’s right in the way!” Seeing faces, reading Dry type Gradual, slowly progressive over many years No specific treatment Wet type Faster onset and progression Treatable with anti-VEGF injections
68
Name the 3 types of glaucoma?
GradualChronicAcute
69
Describe symptoms of gradual glaucoma?
Condition of the optic nerve (2% >40yrs old) Gradual, progressive loss of axons from the nerve inside the eye High pressure is a risk factor
70
Describe symptoms of chronic glaucoma?
Chronic open angle glaucoma Peripheral vision affected first, central vision loss is very late Mostly asymptomatic, painless Largely treated with pressure-lowering eye drops, life long
71
Describe symptoms of acute glaucoma?
Acute closed angle glaucoma Red, painful eye, unreactive pupil, severe headache, unwell patient
72
Describe the symptoms of retinal detachment?
Flashing light or floatersshadow in croner of visionpainlessneeds urgent surgery < 2 daysno inhalation sedation - causes acute eye pressure rises and permanent sight loss
73
Describe the symptoms of giant cell arteritis?
Vasculitis, especially branches of externalcarotid artery A true medical emergency Could present to dentist first >50 yrs Jaw/tongue claudication pain Eating/talking Tender scalp skin Headache Feeling rotten Losing weight (Transient) vision disturbance
74
Name eye related diseases linked with diabetes?
Retinopathy - vitreous haemorrhage - retinal detachment Maculopathy- retinal oedema
75
Describe the symptoms of diabetic retinopathy?
Sugary blood damages vessels Haemorrhages Oedema (especially at macula!) Retinal ischaemia New vessels grow into vitreous (proliferativeretinopathy) Vitreous haemorrhage Retinal detachments
76
Describe the symptoms of orbital fracture?
Bruising Periorbital oedema Pain Double vision up- and downgaze Subconj. Haemorrhage Infraorbital anaesthesia ”Sunken” eye
77
Why are orbital fractures in children more pertinent to address?
Entrapment more common “Bend and snap!” Warrants urgent surgery to preventmuscle necrosis Long term double vision if missed May have little/no outward evidence ofinjury “White eye blow out” Oculocardiac reflex if muscle entrapped Slowed heart rate Nausea/vomiting Syncope/fainting
78
What to do in the case of a chemical injury to the eye?
Irrigate, irrigate, irrigate!!! Tap water, saline, Highland Spring... Ask questions later What is it? Give label to patient Straight to ED Alkalki worse than acids Aim = prevent corneal scarring
79
What is the defintion of Fraility?
A person's mental and physical resistance, or their ability to bounce back and recover from events like illness and injury
80
Name the 2 models of fragility?
Phenotype modelCumulative deficit model
81
What is the defintion of phenotype model of fraility?
Describes a group of patients characterises which, if present, can predict poorer outcomesGenerally individuals with three or more of the characteristics are siad to have frailityCharacteristics:- unintentional weight loss- reduced muscle strength- reduced gait speed- self-reported exhaustion- low energy expenditure
82
What is the defintion of the cumulative deficit model for fraility?
It assumes an accumulation of deficits ranging from symtpoms to disease which can occur with ageing and which combine to increase the fraility index which in turn increase the risk of an adverse outcomeSymptoms:- loss of hearing- low mood- tumourDisease:- dementia
83
Name the 3 main factors which contribute to fraility?
DisabilityMultimorbidityBiological ageing
84
What is the defintion of multimorbidity?
Multiple long term conditions - fraility may be masked due to the focus on their other long term diseases
85
What are the downfalls in the NHS for fraility?
If patient only has fraility, may be low consumers of health care resources and not regularly known to their GP - until the become bed bound immobile or delirious as a result of minor illness
86
Deacribe the comprehensive geriatric assessment - name the 6 factors?
PhysicalSocioecononic/environmentalFunctionalMobility/BalancePsychological/MentalMedication review
87
Why is the comprehensive geriatric assessment successful?
Effective in secondary care:- reduced mortality- improved independence for older people - reducing hospital admission and readmission- reduced the impact of fraility- reverse the progression of fraility
88
Explain the plan created after the comprehensive geriatric assessment
AssessmentCreation of problem listPersonalised care planInterventionRegular planned view
89
How does ageism have an affect on the elderly
Associated with poorer physical and mental healthIncreased social isolation and lonelinessIncreased depressionGreater financial insecurity Decreased quality of life Premature death
90
What is the defintion of delirium?
Sometimes called acute confusional state- is an acute fluctuating syndrome of encephalopathy causing disturbed consciousness, attention cognition and perception It usually develops over hours to days Behavioural disturbance, personality changes and other psychiatric features may occur8-17% of A&E admissions for elderly
91
What is the defintion of capacity?
Means the ability to use and understand the information to make a decision and communicate any decisions Capacity assessment can be challenging Involvement an discussion with next of kin or proxy is a key step
92
What must you consider to decide if a patient has capacity?
Mental disorder:- mental illness- learning disability- dementia - acquired brain injury- severe communication difficulties due to physical disability (stroke or sensory impairment)- of sonhas it made the person unable to make decisions
93
How to explain things to patients with limited capacity?
Action or decision needed- Why the action or decision is needed- Likely effects of decision - Likely effects of not making decision - Any other choices open to the personUse broad terms and simple language
94
Explain the 2 strands to understanding for capacity?
There is having a grasp of the factsThe ability to weight up the options and forsee the different outcomes or possible consequences of one choice to another
95
What is the defintion of limited capacity?
Faced with choices, a person should be able to understand and weigh up information about options and any risks involved- and acy on the decision.In certain cases, an adult may be able to understand the information but unable to act due to their physical or mental impairment
96
What is the defintion of polypharmcy?
Five or more medications - use of multiple medications that are unnecessary and have the potential to do more harm
97
Describe the deprescribing process of medications?
Review mefsIdentify inappropriate, unnecessary or harmfulPlan deprescribingRegularly review
98
What are the symptoms of anticholinergic burden?
Symptoms:- brain - drowsiness dizziness, confusion and hallucinations- heart - rapid HR- bladder - urine retention- skin - unable to sweat- bowel - constipation- mouth - dry- eyes - blurred vision
99
What is the defintion of anticholinergic burden?
Several commonly prescribed medications may not be thought as anticholinergic but do have significant anticholinergic effects+ on top of actual anticholinergics will cause adverse effects.
100
Medications that have anticholinergic side effects?
AntihistaminesTricyclic antidepressantsAsthma drugCOPD drugs
101
What other cause can cause fraility? And risk factors
Clostridium difficileRF:- antibiotics- advanced age- prolong hospital- ppi use- chemo- ckd- IBD- low vit d
102
How to diagnose post-treatment disease?
may not be straight forward as you may be dealing with partially treated pulp canals, missed canals or procedural mishaps. These should be included in the diagnostic description.
103
What is included to enable you to gain a good pain history?
When RCT was fine and if any problems arisedRubber dam used?Check for:- swellings/sinus- TTP- Mobility - PPD > 3mm- tenderness on buccal palpationSpecial tests:- hot and cold sensitivity
104
Remember the SLOB radiography rule?
SAME lingualOpposite BuccalIf you move the x-ray head medially the two roots will move dismally but the buccal one will be the opposite direction of the movement and the lingual will be the one in the same direction
105
Name the 3 diagnostic categories for post treatment disease?
Previously treated:- (a)symptomatic PRP- chronic apical abscess- acute apical abscess
106
Name the 4 causes of post treatment disease?
Intraradicular microorganismExtraradicular infectionForeign body reactionTrue cyst
107
Name the 9 possible reasons for the canal to have intra-radicular microorganisms?
Poor access cavity designUntreated major or minor canalPoorly prepared canals or poorly obturated Procedural complicationsLedgesPerforationsSeparated instrumentNewly introduced microorganisms Coronal leakage
108
Name the 8 main reasons for endodontic treatment failure?
1. Leaking around intubation2. Non-treated canals3. Underfilled 4. Complex canal system5. Overfilled6. Iatrogenic7. Apical biofilm8. Cracks
109
What is the definition of an extraradicular infection?
Microbial invasion and proliferation into the preriradicular tissues. - perio endo lesion where pocketing extends to the apical foramina- extrusion of infected dentine chips during instrumentation- overextended instrumentation/filling materialBiofilms which grow through the apical constriction and form an external apical biofilmExtraradicular microbes
110
What is the defintion of a foreign body reaction?
In the periradicular tissue have been associated with a chronic inflammatory response:- vegetables - cellulose fibres- onturatiob material (sealer or GP)
111
What is the defintion of a true radicular cyst?
Form when retained embryonic epithelium begins to proliferate due to the presence of chronic inflammationCan't tell between abscess, granuloma or cyst - radiographically
112
Cystic characteristics in a radiograph?
The larger it is, the more likely it'll be cystic However, treatment is still the same
113
Name and deacribe the 2 types of radicular cysts?
True radiculsr cyst:- an enclosed cavity totally lined by epithelium - no communication with RCS- not heal after RCTPeriapical pocket cyst:- epithelium is attached to the margins of the apical foramen- cyst lumen is open to the infected canal and hence can communicate directly- heal after RCT
114
Name the 7 things beware of when treating a tooth for an RCT?
History of bruxingHistory of frequent decementingOcclusal wear facetsLarge/wide RCT/PostsLarge, narrow perio pocketsCan also indicate a perio endo lesionLook for vertical root fracture
115
What is the most common cause of failed RCT?
Persistent or secondary infection of the RCSSecondary intraradicular infections Microbes are not present in the primary infection but have been introduced later
116
What species of bacteria can be found as a secondary intraradicular infection?
PropionibacteriumActinomycesPrevotellaE.faecalusStreptococcusCandida albicansFusobacterium nucleatem Spirochaetes Different combinations of bacterial can cause different ways of treatment failure
117
What are the 4 options after diagnosing a treated tooth with lost- treatment disease?
NothingNonsurgical ExtractionSurgical
118
When should Do Nothing be suggested for a patients failed RCT tooth?
No signs nor symptoms form the tooth and the radiolucency is not increasing in sizeEvidence shows that it has little chance of becoming symptomatic
119
When should extraction be suggested?
When tooth has an obvious hopeless outlook
120
When should non-surgical re-treatment be suggested for a failed RCT?
The safer option that surgicalMost benefit with lowest riskGreatest likelihood of eliminating most common cause (intraradicualr infection)But could be more costly than surgical treatment and longer
121
When should surgical treatment be suggested for a patients failed RCT?
Surgery is chosen when no surgical re-treatmebt is not possible, or where the risk to benefit ratio is outweighed by surgeryRCTs can be improved, but somethings can be rectified
122
What are the aims of root canal re treatment?
Re treatment aims to regain access into the apical 1/3 of the the root canal system and create an environment conductive to healingNeed:- coronal access (remove restorations)- remove all previous obstruction material- manage any complicating factors - achieve full working length- eliminate microbes
123
Should you remove the crown/bridge or not? Advantages and Disadvantages of keeping/removing?
Decision is easier if it is defective or replacement is requiredAdvantages of retaining the restoration:- cost for replacement avoided- isolation is easier- occlusion preserved- aesthetics maintained Disadvantages of retaining indirect resto:- removes dentinal core reduction retention and strength- increased change of iatrogenic mishap as restricted vision - removal of canal obstructions more difficult- may miss something important
124
Name the 2 techniques to remove the crown without destroying it?
WAMKEY - dentsply mailleferMetalift system
125
What influence the difficulty of post removal?
Fairly predictable Depends on the post, location in mouth and material cemented with
126
How to remove a post?
What it was cemented with and when the last time it came outBonded restorations are more difficult to remove
127
Consider the types of post material? Name 2
Dentatus screw Quartz fibre - more time consuming
128
What arenthe initial considerations when thinking about how to remove a post?
Location in the arch of the tooth that requires post removalThe more anterior in the arch, the more difficult to remove due to accessibilityTo remove a post firt remove all restorative materials all around- use ultrasonics
129
Explain the way in which you'd remove the metal posts?
Ultrasonics- eggler post removerRuddle/Gonon post remover- masseran kitIf metal threaded, can often unscrew using Spencer Wells or similar Quartz fibre posts - pilot hole then piezo reamerZirconia and ceramic post- often irretrievable
130
Explain the process of post removal with ultrasonics?
Rubber damMagnification and illumination Aim to reduce the retention sing ultrasonics at the interface between the post and the toothConstantly move it around the circumference of the post to disrupt the cement along the post/canal wall interfaceUse copious coolant sprayOwing to the heat that can be generated, stop every 15s
131
What to do if ultrasonics don't work?
A post puller is required
132
Explain the Eggler post removal system?
Post pullerDevice consists of two sets of jaesnrhay work independently - first jaw grips the core- the other jae pushes away from the tooth in line with the long axisA cast core may need reduced with a high speed hand piece - not recommended for the removal of screw posts
133
Explain the Ganon/Ruddle post removal system?
Effective for removing parallel or tampered non-actice preformed posts Hollow trephine bur played over the trimmed down postTrephine domes off tip of post to allow specific, matched size extraction mandrel to create a thread onto the exposed portion of the postThe extraction mandrel is attached to the post, the extraction vice is applied to the tooth and postTurning the screw applies a coronal forceBut vice large access in molar/crowded incisors is difficult
134
Explain how to remove fibre posts?
Often come with drill for removalNeed magnificationCan drill a pilot hole in the long accessSet a silicone stop at the depth of the post on the reamer and slowly take to this lengthLN burs v usefulSpeed at 600-900rpm
135
How to remove a fractured post?
Masseran Kit
136
Name the 6 potential complications of post removal?
Inability to removeTooth is unrestroable Head transmission to PDL from ultrasonicsTooth/root fracturePerforation of rootFracture of post and inability to remove
137
How to gain access to the RCS on a RCT tooth?
Once coronal access is gained remove any residual cement using an ultrasonic blocking access jntonthe RCS
138
What should happen if the tooth has limited access?
If not possible to remove lost, surgery can often be performed
139
Name 3 types of ways to remove GP?
Solvents:- chloroform, halothane and oil of turpentineThermal- ultrasonic - system bMechanical- rotary NiTi files (ProTaper D)
140
Explain how to use chemical solvents to remove GP?
Very small amount in luer lock syringeToxic if extrudedLeave in canal for a minute then working into HP with a C+ file or a 15 or 20 hedstrom When all GP removed, add more solvent into canal and wick out paper points
141
Explain how to mechanically remove GP from the canal?
Rotary Notice files- Mtwo R- ProTaper DUse at 600rpmAlways crown down Active tip to penetrate GP
142
In which order should you use the ProTaper D files?
D1 16mmD2 18mmD3 22mm
143
Removing carrier based systems?
Much more difficult with more errors chance
144
Guttacore
New
145
What to do after bulk of GP is removed?
Flood canals with solventUse paper points to wicj out remains GP and sealerCarefully use hedstroms
146
Explain the irrigant protocol?
NaOCl EDTA or citric acidPovidone iodine soakNaOClUse copious irrigationOnce working length is reached progressively larger diameter hand files are rotatwd passive, nonbinding, clockwise direction to remove the remaining GP until the files come out of the canal clean
147
Explain why silver points are bad for RCTs?
Poor success rate of RCT with pointsNot adaptable ti canal, limited seal and toxic productsDo not retreat in single visit as risk of flare up
148
Explain how to remove a silver point?
Never apply ultrasonic energy directly on point - will disintegrateDifficult to removeGrippable using stieglitzDon't twistApply ultrasonic indirectly to the stieglitz and vibrate out
149
Name the 4 options to fill the canals for retreatment?
Insoluble resinGPSilver pointsSoluble pastes
150
How effective are electronic aplex locators for retreatment cases?
Frequently misread the working lengthRegain accuracy when clean
151
How successful is retreatment?
Reduced success compared to de novo
152
What is the defintion of endodontic success?
If survival is used as the outcomes, longer is betterIf bony infill is taken as successful the more infill the better
153
What does retreatemnt rely on?
Maginficaiton and illumination and successfully removing all obtruation material
154
Name the 3 ways in which there is communication between the pulp and periodontium?
Dentinal tubulesApical foramenLateral/accessory canals
155
How can dentinal tubules becomes exposed?
Developmental defectsDisease processesSurgical proceduresTrauma
156
Name the 4 types of morphology of the CEJ?
I: cementum iver enamelII: Edge to edgeIII: gap IV: enamel over cementum
157
What is the defintion of the apical foramen?
Is the principle route of communication between pulp and periodontiumPulpal inflammation can cause localised inflammatory reaction in the peridontium May be exposed due to severe LoA
158
Where are most lateral canals found?
Middle 1/330-40% have lateral canals - found apicallyContain CT and BVsFurcal canals
159
Explain the problem of potential for exposed furcal canals?
All teeth with furcation involvement can potentially have exposed fiscal canalsLesions suggested radiographically may be due to infectious products from a necrotic pulp diffusing down a furcal or lateral canalsRemember sensitivity testing:- lower 46 and 36 DL root- Upper and lower premolars can have between 1-3 roots- Canines have can 2 roots
160
Bacteria found in chronic/asymptomatic PRP and chronic peridontitis?
Aggregatibacter actinimycetesmcomitansP gingivalisEikenellaFusobacteriumP intermediateTreponema denticola
161
Name the 4 iatrogenically occurring communication between pulp and periodntium.
Developmental malformationsResorption lesionsPerforationsCracksMucosal fenestration
162
Name 3 types of developmental malformations?
Palatogingival grooves- upper incisors- maxillary lateral incisorsIf the epithelial attachment is breached, grooves becomes contaminated Self-sustainjng infrabony pocket developsLoA can quickly extend to the apical foramen causing pulapl necrosis Treatment:- difficult- scaling and RSI don't work- bur out grooves and use regenerative techniques
163
Name 3 types of responsive lesions?
External inflammatoryInternal inflammatoryCervical inflammatory
164
What are the requirements of resoprtive lesions?
An injuryA stimulus
165
Describe an internal inflammatory root resorption?
Only associated with increased probing depths and BOP when resorptive process has perforated through root
166
Describe an external inflammatory root resorption
Associated with increased probing depths and BOPIn late stages, can interfere with gingival sulces and result in periodontal abscesses
167
Describe a cervical inflammatory root resorption?
Starts where the JE attaches to root surfaceMicrobes in the giving sulcus situate and sustaon the resorptive processAssociated with increased probing depths, gingival swelling and BOP
168
What is the defintion of a perforation?
Caused pathological by caries or iatrogenically by procedural errorsPresent with perio abscess - pain, swelling, pus draining and with infrabony pocket developing Having perforated an acute inflamamltry action will occurCloser to the gingival sulcus, increased likelihood of apical migration
169
What affects the prognosis of a perforation?
Location - mid to apical third better outlook as bounded by bone, but advanced perio badTimeAbility to sealChance of new attachment Accessibility to RCS
170
Describe a horizontal root fracture?
HorizontalPocket formation may occur - coronal 1/3 root fractureCan present with perio abscess or Deeping of perio pocket
171
Describe a vertical root fracture?
VerticalMicrobial colonisation of crack space = periodontal inflammation = breakdown of CT and alveolar bone leading to deep infrabony pocket
172
How to diagnose vertical root fracture?
Parallax x-rayJ shaped radiolucencyPerio abscess or deepening periodontal pocketDeep, narrow pocket, pain on biting pain, abscess and chronic sinusSurgical exploration but hopeless prognosis
173
What is the defintion of a mucosal fenestration?
Pathological condition characterises by the perforation of the alveolar bone playe and overlying mucosa by the roots of the teeth
174
Name the 4 aetiologies of mucosal fenestration?
Root prominenceDevelolmenral anomaliesChronic periradicular Orthodontic tooth movement
175
Treatment for mucosal fenestration?
Generally asymptomatic but are plaque retentive factors Causes of exposed root end further periodontal destruction ingress of bacteria into the RCSTreatment:- endodontic treatment- surgery- CT graft
176
What is the defintion of a furcation?
horizontal loss of bony support in areas where roots of multi-rooted teeth conerge
177
What is the aetiology of furcations?
result of plaque indcued inflammationworse in elderly patientsPRFs
178
Which teeth affected?
All multi-rooted teethAll molars, 14 and 24Check from radiographs
179
How to investigate a furcation for a maxillary molar?
Mesio=-palatally, buccally and then distally
180
How to investigate a furcation for a maxillary premolar?
Check mesially and distallyroot bifurcation loacted at the mid-apical third- unsuitable for root resection
181
How to investigate a furcation for a mandibular molar?
Check buccally and linguallyMesial and Distal rootMore around the 6s as hinner buccal bone
182
What difference does a furcation have on a mandibular or maxillary molar?
Mandibular:- even if severe only buccal and lingual bone plates affetced- as long as no interproximal bone lossMaxillary:- potential for severe damage to the mesial and distal bone areas, affecting adjacent teeth- needs more aggressive strategies
183
How to diagnose a furcation involvement?
If you can prod it with your probeRadiographs can confirm your suspicisions and confirm amount of bone loss
184
Differential diagnoses for furcation?
Occlusal trauma widens the PDL and causes bone lossDo a sensibility test to identify vital or non-vital
185
How to treat a furcated tooth that is non-vital?
Endo treatemnt always prior to periodntal treatment
186
How to treat a furcated tooth that is vital?
TRreat as plaque induced periodontal disease and review for further sensibility testing
187
How to clinically assess a furcation?
Probe around circumferenceDetermine extentFactors attributing to itMorphologyFactors affecting treatment
188
Best tool for furcations?
Nabers
189
Root trunk length affecting RCT?
shorter can be exposed but more accessible
190
Root length affecting RCT
SHort roots may have little root left invested in bone, reduce functional demands
191
Root form affecting RCT?
awkward shapes can make access difficult
192
What part of the furcation anatomy can make RCTs harder?
ConcaviitiesAccessory canalsBifurcational ridges
193
What is the definition of cemento enamel projections
Enamel below gingival margin
194
What is the defintion of an enamel pearl?
Enamel below gingival margin in a pearl shape
195
Name the 3 grades of furcation severity?
IIIIII
196
Describe Degree I furcation?
Horizontal loss of peridontal support not exceeding 1/3 width of tooth
197
Describe Degree II furcation?
Horizontal loss of peridontal support exceeding 1/3 width of tooth, but not encompassing the tota width of furcation area
198
Describe Degree III furcation?
Horizontal loss through and through destruction of periodontal tissues in the furcation area
199
Name the potential consequences of furcation involvement?
CariesPulpal exposuirePulpal necrosisFUrcal/accessory canal microbial invasion - pulpal death
200
Name the 2 objectives for RCT in furcated teeth?
Eliminate microbial plaque from the exposed root surfaceEstablish an anatomy condutive to effective plaque controlNeed a plaque free zone
201
Name the 5 treatment options for a degree I furcation?
Repeated scalingMechanical non-surgical debridementFurcationplastyElimate plaque trap via smoothingPokcet elimination surgery
202
Non-surgical therapy for furcation treatment?
OHINeeds furcation accessScaling and RSI
203
Wht is the defintion of furcationplasty?
a surgical resective treatment to eliminate the interradicular defectB or lingual furcationsTooth substance removed and alveolar crest remodelled at furcation level entrance
204
Name the treatment options for a degree II furcation?
FurcationplastyTunnel prepRoot resectionGuided tissue regenEnamel matrix derivativeTooth extarction
205
Name the treatment options for a degree III furcation?
Tunnel preproot resectionextraction
206
What is the definition of tunnel preps?
surgical treatment for DII and III furcationsNeeds unfused rootsFlap reflectyed and granulation tissues removeed, root surfaces scaled and RSIWidened furcation area - allow easy teepee accessFlaps replaced in more apical areaHigh risk for sensitivity
207
What is the defintion of root resection?
Surgical division and removcal of roots of multi-rooted teethGood for uneven bone supportMust seal rootMust devitalise toothBets to RCT beforeMax amount of dentine savedDirect resto after obturation
208
Which root to remove for resection?
The root or roots that will elimnate the furcationGreatest amount of bone loss of LoASave better roots, lose worse roots
209
What is the ideal goal for regenaration?
regenrate lost attachmentnew formation of cementum, functionally orientated PDL, alveolar bone and gingivaPDL cells have ability to regen
210
What is the defintion of an inlay?
Is an indirect intracoronal restoration, places in a prepared cavity space
211
Name the 3 principles of inlays?
Wedge retentionStress proportionak to cusp height and width of isthmus No reinforcement of remaining tooth structure - marginal leakage- cusp fracture - loss of restoration
212
Name the indications of inlays?
Same as for direct restorations
213
Name the 3 contraindications of inlays?
Caries; MOD on premolars and wide isthmus MOD on molarsRoot filled teeth
214
What is the defintion of wedge retention?
The stress should be transmitted to tooth tissueEffective height of the lingual cusp - possible fracture of vulnerable cusp
215
What is the definition of an onlay?
Is an indirect extracoronal restoration, usuallynplaced after tooth surface reduction
216
Name the indications of onlays?
Cuspal coverageRestoration of Functional cuspRestoration of lost tooth tissue
217
What isnthe difference between a direct and indirect restorations?
Direct:- places by operator chair side - plastic material- no conventional or digital impression neededIndirect:- fabricated outside the mouth in a lab and cemented as a rigid unit- impression required
218
Name the 3 types of materials for inlays and onlays?
MetalCompositePorcelain
219
What are the advantages and disadvantages of using precious metal for an inlay or onlay?
Low corrosionLow wear to opposing teeth Relatively easy to cast and adjustCan be considered aestheticExpensiveDifficult to bond directly to surface (surface treatment required)
220
What are the advantages and disadvantages of non-precious metal?
Very hard metal and so difficult to adjustGreater wear to opposing teethSome alloys have low corrosion resistanceNot much cheaper than preciousSilver in colourBond well to composite
221
What are the advantages of indirect composite?
Good aestheticsLess expensive Easier to repair Poor wear resistance
222
Name the 4 ways in which a inlay/onlay is retained in a cavity?
Luting cementsMechanical retentionBindingMicro-mechanical retention
223
What is the defintion of a luting cement?
Fills hap between restoration and cavity
224
What is the defintion of mechanical retention?
Parallex axial walls and resistance form
225
What is the defintion of bonding?
Chemical adhesion between restoration and cavity
226
What is the defintion of micromechanical retention?
Retention due to adhesive nagerial locking into surface irregularities
227
Mechanical retention and resistance?
Load applied to lingual cusps, lead to the buccal cusps to lift off, and creater a point of rotation at the base of the lingual wall
228
How to bond tooth tissue to the restoration?
Most need resin based cementsBase metal - MDP or 4 METACeramic - silane coupler Noble metal - high Cu, Sn plating with MDPAugmented by surface treatments- sandblasting- HF to etch ceramic
229
Name 2 types of surface treatments?
Sandblasting metalHF to etch ceramic
230
Explain enamel bonding?
Etching of enamel surfaceMicromechanical retentionHowever sensitive to contamination
231
Explain dentine bonding?
Conditioning of dentineAdhesion to the hybrid layerHowever sensitive to contaminationRequires hydrated dentine
232
How important is surface roughness?
Is important when trying to create micromechanical retention- which is why surfaces are treated to increase the roughness
233
What are the principles of ceramic onlays?
Compared with metal restorations, ceramic or composite indirect restorations:- requires bulk for strength- greater extension on proximal (finishing)- rounded internal angles (reduces stress concentration)- greater taper of walls (less retention required because bonded; manufacturing technique) - are bonded to tooth tissue
234
Describe the requirements of gold inlays/onlays (cavity prep)
1-1.5mm occlusal clearanceSharp internal anglesBevelled shoulders in box and on functional cusps (onlay)Proximal flare6-10 degrees occlusal divergence in isthmus and boxesIsthmus bevel (inlay)Minimal proximal extension Luted to tooth
235
Describe the requirements of ceramic inlays/onlays (cavity prep)
1.5-2mm occlusal clearanceRounded internal angles90 degree finish lines in box and on all cuspsNo bevels1mm shoulder12-15 degree occlusal divergence in isthmus and boxesGreater proximal extensionBonded to tooth
236
Explain the step by step guide to create a cavity for an inlay indirect restorations?
Matrix for temp/guide reductionPlace damRemove old reatoEvaluate tooth for appropriate restoration - block out minor undercuts in GICPrepare occlusal portion Prepare proximal boxes Pcclusal clearanceFinish marginsTemporariesImpressions
237
Describe the requirements of a metal MOD onlay cavity?
Proximal boxProximal flareIsthmusBuccal bevelOcclusal reductionFunctional cusp bevelOcclusal bevelLingual bevelGinguval bevel
238
Describe the cavity requirements for a metal onlay?
1mm planar occlusal reduction1.5 mm for functional cuspBuccal cusp needs a bevelFunctional cusp line = shoulder or heavy chamferSharp internal anglesProximal bevel and flare
239
Describe the cavity preparation for a cermaic/composite onlay?
1.5 mm planar occlusal reduction 2 mm for functional cuspBuccal cusp needs a butt finishFunctional cusp finish needs a shoulderRounded internal angleNo proximal bevel or flare
240
Explain how to create a temporary restoration?
Apply vaselune to plastic teethMix composite - ProTemp/integrityPlace composite in matrixSeat over prepFollow manufactures instructionsAdd flowable composite to fill any voidsTrim excess with soft flex discs
241
Manufacturers instructions for ProTemp?
49 second working time1:40 m for setting in mouth2:50 m for matrix removed 5:00 m removal from matrix and finishing
242
Notes for clinic?
Full arch impression required - light and medium bodied silicone- opposing arch in alginateBiscuit try in (ceramic)Return to lab for glazingTry in Cement
243
Name the 3 types of resin-retained bridge support?
Impant supportedTooth supported with minimal prepTooth supported with heavier prep
244
Describe the advantages of resin-retained bridgework?
#NAME?
245
Name the 3 principles to bridges?
Area of coverageThickness of retainersControl of the occlusion
246
Name 3 types of bridges needing little to no tooth prep?
CantileverFixed-FixedHybrid
247
Describe what is a Cantilever bridge?
1 or 2 abutmentsindicated for short spans generally anteriorall-ceramic resin-retained bridges
248
Requirements for a Fixed-Fixed bridge?
Framework design must have a retainer thickness of 0.7mmControl of the occlusionApproximal guide planesMaing use of relative axial tooth movementOcclusal considerations may impact the design
249
Does tooth prep improve outcome of bridges?
No evidence has been found
250
When is tooth prep necessary?
when creating guide planes to allow connector height
251
Describe the framework coverage for resin-retained bridges?
Coverage from incisal edge up to the wall apical to the cingulum* Extension into the approximal areas* Maximum mesio-distal wrap-around* Minimum 0.7 mm thickness
252
Name the best bridge style for post-ortho retention?
fixed-fixed designs for maximal coverage- cantilevers will not be stableProximal contacts will not provide post-orthodontic stability
253
What is the classical design for posterior tooth replacement?
Classical design:180 degrees axial coverageRest seats adjacent to the pontic areaTooth preparation to create guide planes nearly always essentialGuide planes close to parallel - 6-10 degreesOcclusal coverage - 0.7mm - provides greater securityMaking use of relative axial tooth movement
254
What to treate the fitting surface of the bridge with?
Sandblasting with either Ni-Chr or Chr-Co alloys
255
When to do finishing of the bridge?
only at cermentation visitif possible delay finishing with roatry instruments for at least 24hrs
256
What is the definition of a bridge?
A prosthetic tooth replacement that is fixed to at least one natural tooth or dental implant
257
Name the 4 components of a fixed-fixed conventional bridge?
Abutment toothRetainerConnectorPontic
258
Name the 5 aims of restorations?
AestheticsFunctionComfortOcclusal stability Maintainable
259
Describe a resin-bonded bridge?
Retainer is a metal wingConventional cantileverResin retained cantilever bridge
260
Describe a conventional bridge?
Retainers are usually a full coverage crown
261
Indications for removable denture (contraindications for fixed protheses)?
Many missing teeth (multiple or longspan) simplifies treatmentPrognosis of remaining teethYoung patient Sports playerGross alveolar resorptionLack of suitable abutments for bridgework Midline diastemaPoor patient motivation
262
Name 5 reasons for a fixed rather than a removable prosthesis?
More acceptableDoes nor cover the gingival marginDirects forces axiallyRestores the occlusal anatomy Prthodonric retention or periodontal splinting
263
Describebthe conventional cantilever bridge design?
Pontic is connected to the retainer at one end only A single retainer more conservative than 2Leverage imposed on abutment teethSuitable for limited span lengthNot for use with heavy occlusal forces on the pontic
264
Name the indications for conventional cantilever?
Short spans generally anterior
265
How many abutments are necessary for a bridge?
Double abutments can increase the risk of loss of cementation
266
Why can double abutting be a disaster for bridges?
When pontics flex secondary abutmens are placed in tension and may debond Sometimes its necessary however the distal wall of the secondary butment should offer very good resistance formTensile forces are transmitted to distal retainerCemebt failureCaries of distal retainer
267
Describe a spring-cantilever bridge?
Obsolete
268
Describe the conventional fixed-fixed bridge?
Pontic is connected to 2 retainersNot conservativeLess torque compared with cantilever Better for longer spans, and heavy occlusal loadsSignificant biomechanical and biological issues
269
Explain the requirements for a fixed-fixed conventional bridge?
All joints are soldered or cast in one piece to connect all abutment teethRequires good retention at either end of soabPreps must be parallelSingle path of insertion and removal
270
How can taper affect the bridge retention?
An increase in taper leads to decreased resistance form and increased stress on the cement lute
271
Describe the occlusal forces for a bridge?
The direction of occlusal forces is dependant on position in the archDistance and direction of tooth movement during function translate to stress on luteIn fixed-fixed designs each abutment should provide equivalence of retention
272
What are the risks associated with fixed-fized designs?
Decementation of the retainer
273
Why does a fixed-fixed bridge need more resistance form?
Due to the rotational arc of displacement is increased
274
Describe fixed-movable designs of a bridge?
Short spansAlignment of abutmentsQuality of abutmentsIndependent mobility of teeth Advantage for short posterior spans A stress breakerAngled abutmentsProvisions for failure Needs modification to tooth prep
275
Name the different types of retainers?
3/4 gold crownFull veneer crown- gold- mcc- ceramic
276
Describe the Shillingberg's principles of tooth prep
Preserve tooth structureStructural durability of restorationRetention and resistance formMarginal integrityPreservation of the periodontiumAesthetics
277
Name the pros and cons for a 3/4 crown for a retainer in a bridge?
More conservative than a full veneer crownRetention/resistance porter than full veneerStructurally weaker due to open face Modest chamfer and occlusal reductionLong margin for failureSupragingival marginsAesthetics
278
Name the pros and cons for a full veneer gold crown for a retainer in a bridge?
Requires prep of all coronalmtissueVery good retention and resistanceStrong structurallyBurnish margins to achieve good adaptionPreserve periodontiumPoor Aesthetics
279
Name the pros and cons for a metal cermaic crown for a retainer in a bridge?
Requires prep of all coronal tooth tissueVerg good retention/resistanceStrong structurallyDestructive prepPreserve periodontiumGood aesthetics
280
Name the pros and cons for a all ceramic crown for a retainer in a bridge?
Abutments need heavy prep to give greater taper and thicker cermaic layerGood resistance and retention Structural durabilityVery aesthetic
281
Name the 4 factors affecting the selection of abutments teeth?
Suitability of patientSuitability of oral environment Suitability of position of abutmentSuitbailiry of tooth and supporting structures
282
How to assess the suitabilitybif a patient for a bridge?
MHPDHSH
283
How to assess the suitability of the oral environment?
HT ChartingPeridontal chartingParafunctionOcclusion
284
How to assess the tooth for a bridge?
Special testsInvestigations
285
How to assessnthe suitability of the position of the tooth for a bridge?
Bridge mechanics:- length of span (Ante law)Curvature of spanAngulation of teeth Position of span in arch
286
How can the length of span affect your bridge?
No more than 2 pontics for fixed fixed and 1 for cantilever
287
Describe Ante's Law?
The root surface area of the abutmentntooth should be equal or surpass that of the teeth being replaced with pontics
288
Why should you avoid long span bridgework?
Flex = stress to abutment and cement lutePlaces increases load on PDLAny bridge replacing more than 2 units high risk
289
Equation for flexibility?
PL3/EDWP - loadL - lengthE - modulus of elasticityD - dimension perpendicular to loadW - dimension laralll to load
290
How can curvature of the span affect the bridge?
Pontics lying outside of the interabutment axis will act as a lever
291
How can angulation of a tooth affect the bridge?
To achieve parallelism prep misg be very heavyNon axial loading of teeth can cause occlusal trauma
292
Support requirements for an abutment teeth?
Root configuration- surface areaLength of clinical crownCrown to root ratio:- ideal 1:2- good 2:3- acceptable 1:1
293
Why are root filled teeth bridges more likely to fail?
Vulnerable to fracture- coronal access removes roof of pulp chamber- canal prep reduces bulk of dentine- posts even worse
294
What to assess for an abutment tooth?
Occlusal forcesIntegrity of existing restorationCrown heightCariesPeriodontal supportPulpnheslthEndonstatisRoot fillings?Post and cores?Periapical statusCrown toot rariib
295
Describe the ideal occlusion for a bridge?
Posterior stabilityincisal/canine guidanceAbsence of posterior interference on mandibular movement
296
Describe what is involved for pontic design?
Ridge lap Modified ridge lapBullet OvateHygienic
297
Deacribe a hygienic pontic for a bridge?
Better for perio health, space for flossingNot aesthetic Food trapping
298
Describe a bullet pontic for a bridge?
Wide embrasures to facilitate cleaning AestheticNon space for food trappibgq
299
What things to check for when assessing whether a RCT'd tooth has been successful?
Lack of symptomsNo painNot TTPNo palpation painNo swellingRadiographic healingFunctional and aestehtic tooth
300
Describe radiographically a failed RCT?
Presence of a periradicular radiolucency, unchaned or a new increased rarefraction
301
When does a RCT'd tooth new re-reatment?
If the GP has been exposed in the mouht for some timeORif post-treatment disease has been diagnosed
302
What factors dictate whether a tooth has a good prosthodontic prognosis?
The quality and quantity of remaining tooth structure is the single most important factor
303
What to assess in the root filled tooth?
Remove all caries, restorations and assess the quatity distribution and quality of tooth substance remaining
304
What is the ferrule's effect?
The remaining coronal tooth tissue offers retention, resistance and a substrate to bond to
305
What is the defintion of the ferrule?
A metal ring or cap intended to embrace the tooth structure cervically to achieve root strengthing and prevent shattering of the root2mm H1mm W (from post hole to margin)
306
What factors influence the ferrule?
A longer ferrule increases fracture resisatnce significantlyAlso resists lateral focres from the posts and leverage from the crown in functionIt increases retention and resistance of the restoration
307
Name the 5 requirements for a successful crown/crown prep?
Ferrule (dentine axial wall height) must be at least 2-3mmThe axial walls must be paralledRestoration must encircle toothMargin is on solid tooth structureCorwn and prep must not invade the biologic width
308
What are the clinical complications for missing 1 of the 5 requeirements of the prep?
Root FractureCoronal apical leakageReccurent cariesDislodgement or loss of the corePerio injury - LoA, recession, and bone loss - biologic width invasion
309
What are the 4 advantages for the Ferrule effect?
Provides anti-rotational featuresIncreases longevity of post and coreFailure of restoration tends to be retrievableIncreases the fracture resistance of the RCT'd teeth
310
Is GP antimicrobial?
No
311
How to remove sealer from pulp chamber?
Alcohol
312
How to seal the pulp chamber?
Vitrebond - RMGIC
313
When should we place the post?
Immediately after the prep
314
WHat are the advantages of placing the post immediateyl?
Familiarity with RCS and WLDecreased risk of perfs or excessive GP removalDoes NOT disrupt the apical sealDelayed post space prep does decrease chance of coronal leakage
315
How does length of post influence success of RCT'd tooth restoration?
More important than widthThe longer the post, the better the retentionSiginificant increase in clinical success if longer than the crown heightShorter posts have poor retention and transmit lateral forces to the remaining root structure compared to longer postsNeed for >4-5mm of GP apically
316
What is the ideal width of the post?
Adequate width important for post strength and resistance to fractureOptimum is <1mm width at the tipbut consider root morphology - larger roots can perforate the toothDiameter of the post at its tip should be <1/3 of the diameter of the root at the corrsponding depth e.g. lower incisor .6 and upper incisor 1mm
317
What are the risks of a wider post?
Increased risk of root perfIncreased cervical stressesDecreased impact resistanceDecreased resistance to root fracture
318
Explain how to remove the GP for a post?
Chemical - increased apical leakageThermal - can distub apical GPMechanical - most efficientGG (Gates Glidden) do not causes the large increases in temperature
319
Hand or rotary removal of GP?
Hand less change of iatro and temoRotary greater change of iatro and temo - high torque and low speed
320
Explain the process to remove GP and prep the post hole mechanically?
Use non-end cutting bur GGCuts GPP preferentially than dentine wallsThen use peeso reamers/parapost reamers to finally comple the prep after GP removed (can lead to increases in temp)
321
What are the ideal properties for a luting cement?
InsolublePrevent microleakageAdherere to radciaulr dentine - potentially reinforce rootwithstand fatigiue froces wellCan risk generation microcrack can culminate in the failure of the restoration
322
Name 3 types of traditional luting cements?
ZPC - mechanical means no chemicalGIC - depends on resin content - can bond more to dentineRMGIC - no indicated for posts due to hygroscopy
323
Name the advantages and disadvantages of resin-based luting cements?
Potentially reinforce toothAid post retentionRequire pretreatment with etch and bondadhesives form hybrid layers allong the post space wallsBut bonding to radicular dentine may be affected by NaOCl which is strong oxidising agentLeaves oxygen rich layer on dentine - inhibits poly of resinEugenol diffusing affect retention of bonded post
324
Explain how to use dual cure resin-based luting cements?
Difficult for moisture controlUse self-etch prposed as an alternative, but hard to penetrate smear layerDual cure adhesives developed to ensure better pilymer deeper in rootContain ternanry catalyst to ofset acid base reaction
325
Explain how to use self-adhesive resin-based luting cements?
Alternative to conventional resin-based luting cementsReact with hydroxyapatiteDoes NOT reuire pretreatment of root dentineReduces techique sensitivtyAlso dual cure, and so need lightadhesion similar to multisetp luting cememnt, not recommended for bonding to enmale without phosphoric etchNot clinically proven to work
326
Chemically active resins?
4-METADon't use impossible to remove post
327
Name the advantages of adhesive cementation?
Improved marginal adaptationImproved apical sealIncreased post retention - even for short postsRelives stress in root canalOptimises fracture patterns for re-restoration
328
Name the disadvantages of adhesive cementation?
Difficult to access without magnificationRemnats of acid and debris from prepBondign areas decreased by GP remnants, smear or sealerVoids and gaps in cement interface
329
Name the 4 main aims for resotorative management of root filled teeth?
Presevre tooth structureProtect tooth structureMaintain seal in canalAllow for re-tretment
330
What is the function of a post?
Retain the core when the reamining tooth structure is considerably reducedStress distribution to radicular dentine and alveolar boneNo strengthening effect excepts for fibre posts
331
What infleunce the difficulty of a root filled tooth restoration?
Quantity and location of remaining tooth structureLocation of access cavityConsider the quantity of remaining dentine - coronally, pulp chambers and RCs
332
Indications for a post?
Primary aim is retention for the core when little detine and little useful pulp chamber remain
333
How to choose a post?
PassiveParallel sidedRoughened surfaceEasy to use
334
How long should the post be?
As long as the crown2/3rd of the length of the too50% of the root length surrounded by bondAs long as possible
335
Name the 2 function of the post?
Core retentionStress distribution
336
Name 5 factors that determine the dimensions of the post?
Root lengthRoot diameter - <1/3 diameter of rootExtention of root filling - 5mm min to maintain apical sealClinical crown heightAlveolar bone levels
337
Give an example staging for a cast post and core?
Review RCTPost space prepCrown prepReview anti-rotationCoronal finishing
338
Temporary restorations for the cast post and core?
Indirect - imps + castDirect - resin pattern
339
Comapre the indirect versus direct techniques for temproary restoration?
Indirect:- less surgery time- working imos- opposing cast- shaape of core technician determinedDirect:- increased surgery time- direct pattern- no opposing acst- core shape by operator
340
Name the 3 tools for the parapost?
Temp postImps post (smooth)Pattern post (serrated)
341
Describe the indirect technique for post creation?
Elastomeic impression (wash imps) + lab fabricationUsing smooth imps post
342
Describe the direct technique for post creation?
Colours relate to parapost diameterUsing serrated burn-out post + DuraLay
343
Describe the Nealon Incremental Technique
Lub canal with DuraLay - bead brushForce down canal to express trapped airRecord intra-radicular anti-rotation featureTrim with turbine + diamon + waterspray
344
What to do before trying in post-retained core?
Inspect and remove any casting blebs
345
Name the potential problems for metal posts and cast etal cores?
Radicul;ar fractureCoronal leakageRetriveability
346
Name 3 types of fibre posts?
CarbonGlassQuartz
347
Explain the clinical technique for fibre post placement?
Evaluate pre-Op radioDetermine post length + widthCreate post prep and anti-rotation - before refining coronal prepExtra-coronal prepEval H:W of axial wallsPost lengthFinial finishSelf-etching composite luting cement - Rely X Unicem
348
Name the disadvantages of fibre posts?
Post fractureLoss of retentionBond of composite resin to dentineBond to post
349
What will determine the success?
Amount and location of the remaining tooth structure
350
Why do we need a core?
Provide retention and resistance formRestoration of coronal tissueDurable coronal seal
351
How can we increase retention and resistance using a core?
Use of adhesive materials to bond to toothtissues (crown and core)Use of undercuts and grooves in remainingtooth tissue (core)Use of ferrule (crown)
352
How do we assess the need for a core?
1. Can the tooth provide retention for its extra-coronalrestoration without additional material being added?2. Do we need to add material that will aid resistance andretention, or do we just need to block out irregularities?3. Is there sufficient remaining tooth tissue to retain andsupport a core?4. Can a ferrule be achieved?
353
Advantages of the coronal seal? vital and nonvital?
Vital:➢Provides increased pulpal protection➢Prevents caries at and beneath restoration marginNon-vital:➢Provides additional line of defence to endodontic seal➢Prevents caries at and beneath restoration margin
354
Describe amalgam as a core material? Adv and Dis?
Advantages - Not especially technique sensitive - Strong in bulk section - Sealed by corrosion products - Can be bonded into place withcements and resinsDisadvantages- Best left to set for 24 hours before tooth preparation- Weak in thin section- Potential electrolytic action betweencore and metal crown- Not intrinsically adhesive- Poor aesthetics under ceramicrestorations
355
Indications for amalgam as a core material?
Excellent core build-up material for posterior teeth Excellent interim restoration for posterior teeth Adhesives and preparation features can often substitute for pinretention
356
Describe composite as a core material? Adv and Dis?
Advantages - Strong- Can be used in a thinner section thanamalgam- Fast setting (either light or chemicallycured)- Does not always need a matrixduring placementDisadvantages- Highly technique sensitive- Relies on multi-stage dentinebonding requiring effective isolation- Dentine bond can be ruptured bypolymerisation contraction- Can be difficult to distinguishbetween tooth and core duringpreparation
357
Indications of composite for core build up?
Excellent build-up material for posterior and anterior teeth if isolationassuredAesthetic interim restoration, but takes far longer to place than amalgam
358
Should we remove the exisiting restoration?
Removal of existingrestorations allows properassessment of:➢The tooth's structural integrity➢Pulpal exposure➢Underlying caries
359
Describe the Nayyar core?
“Postless” preparationRetention from coronal and radicular toothtissueUses pulp chamber as retention and resistance form
360
Advantages of the Nayyar core?
Can be placed immediately after endo –reducing risk of coronal leakage Utilises coronal tooth structure to increaseretention Reduces stresses created by post placement Usually easily retrievable
361
What is the definition of an extraradicular infection?
Microbial invasion and proliferation into the preriradicular tissues. - perio endo lesion where pocketing extends to the apical foramina- extrusion of infected dentine chips during instrumentation- overextended instrumentation/filling materialBiofilms which grow through the apical constriction and form an external apical biofilmExtraradicular microbes
362
What is the defintion of a foreign body reaction?
In the periradicular tissue have been associated with a chronic inflammatory response:- vegetables - cellulose fibres- onturatiob material (sealer or GP)
363
What is the defintion of a true radicular cyst?
Form when retained embryonic epithelium begins to proliferate due to the presence of chronic inflammationCan't tell between abscess, granuloma or cyst - radiographically
364
Name and deacribe the 2 types of radicular cysts?
True radiculsr cyst:- an enclosed cavity totally lined by epithelium - no communication with RCS- not heal after RCTPeriapical pocket cyst:- epithelium is attached to the margins of the apical foramen- cyst lumen is open to the infected canal and hence can communicate directly- heal after RCT
365
Should you remove the crown/bridge or not? Advantages and Disadvantages of keeping/removing?
Decision is easier if it is defective or replacement is requiredAdvantages of retaining the restoration:- cost for replacement avoided- isolation is easier- occlusion preserved- aesthetics maintained Disadvantages of retaining indirect resto:- removes dentinal core reduction retention and strength- increased change of iatrogenic mishap as restricted vision - removal of canal obstructions more difficult- may miss something important
366
Name the 2 techniques to remove the crown without destroying it?
WAMKEY - dentsply mailleferMetalift system
367
What influence the difficulty of post removal?
Fairly predictable Depends on the post, location in mouth and material cemented with
368
How to remove a post?
What it was cemented with and when the last time it came outBonded restorations are more difficult to remove
369
Consider the types of post material? Name 2
Dentatus screw Quartz fibre - more time consuming
370
When should we place the post?
Immediately after the prep
371
WHat are the advantages of placing the post immediateyl?
Familiarity with RCS and WLDecreased risk of perfs or excessive GP removalDoes NOT disrupt the apical sealDelayed post space prep does decrease chance of coronal leakage
372
How does length of post influence success of RCT'd tooth restoration?
More important than widthThe longer the post, the better the retentionSiginificant increase in clinical success if longer than the crown heightShorter posts have poor retention and transmit lateral forces to the remaining root structure compared to longer postsNeed for >4-5mm of GP apically
373
What is the ideal width of the post?
Adequate width important for post strength and resistance to fractureOptimum is <1mm width at the tipbut consider root morphology - larger roots can perforate the toothDiameter of the post at its tip should be <1/3 of the diameter of the root at the corrsponding depth e.g. lower incisor .6 and upper incisor 1mm
374
What are the risks of a wider post?
Increased risk of root perfIncreased cervical stressesDecreased impact resistanceDecreased resistance to root fracture
375
Explain how to remove the GP for a post?
Chemical - increased apical leakageThermal - can distub apical GPMechanical - most efficientGG (Gates Glidden) do not causes the large increases in temperature
376
Hand or rotary removal of GP?
Hand less change of iatro and temoRotary greater change of iatro and temo - high torque and low speed
377
Explain the process to remove GP and prep the post hole mechanically?
Use non-end cutting bur GGCuts GPP preferentially than dentine wallsThen use peeso reamers/parapost reamers to finally comple the prep after GP removed (can lead to increases in temp)
378
What are the ideal properties for a luting cement?
InsolublePrevent microleakageAdherere to radciaulr dentine - potentially reinforce rootwithstand fatigiue froces wellCan risk generation microcrack can culminate in the failure of the restoration
379
Name 3 types of traditional luting cements?
ZPC - mechanical means no chemicalGIC - depends on resin content - can bond more to dentineRMGIC - no indicated for posts due to hygroscopy
380
Name the advantages and disadvantages of resin-based luting cements?
Potentially reinforce toothAid post retentionRequire pretreatment with etch and bondadhesives form hybrid layers allong the post space wallsBut bonding to radicular dentine may be affected by NaOCl which is strong oxidising agentLeaves oxygen rich layer on dentine - inhibits poly of resinEugenol diffusing affect retention of bonded post
381
Explain how to use dual cure resin-based luting cements?
Difficult for moisture controlUse self-etch prposed as an alternative, but hard to penetrate smear layerDual cure adhesives developed to ensure better pilymer deeper in rootContain ternanry catalyst to ofset acid base reaction
382
Explain how to use self-adhesive resin-based luting cements?
Alternative to conventional resin-based luting cementsReact with hydroxyapatiteDoes NOT reuire pretreatment of root dentineReduces techique sensitivtyAlso dual cure, and so need lightadhesion similar to multisetp luting cememnt, not recommended for bonding to enmale without phosphoric etchNot clinically proven to work
383
Chemically active resins?
4-METADon't use impossible to remove post
384
Name the advantages of adhesive cementation?
Improved marginal adaptationImproved apical sealIncreased post retention - even for short postsRelives stress in root canalOptimises fracture patterns for re-restoration
385
Name the disadvantages of adhesive cementation?
Difficult to access without magnificationRemnats of acid and debris from prepBondign areas decreased by GP remnants, smear or sealerVoids and gaps in cement interface
386
Name the 4 main aims for resotorative management of root filled teeth?
Presevre tooth structureProtect tooth structureMaintain seal in canalAllow for re-tretment
387
What is the function of a post?
Retain the core when the reamining tooth structure is considerably reducedStress distribution to radicular dentine and alveolar boneNo strengthening effect excepts for fibre posts
388
What infleunce the difficulty of a root filled tooth restoration?
Quantity and location of remaining tooth structureLocation of access cavityConsider the quantity of remaining dentine - coronally, pulp chambers and RCs
389
Indications for a post?
Primary aim is retention for the core when little detine and little useful pulp chamber remain
390
How to choose a post?
PassiveParallel sidedRoughened surfaceEasy to use
391
How long should the post be?
As long as the crown2/3rd of the length of the too50% of the root length surrounded by bondAs long as possible
392
Name the 2 function of the post?
Core retentionStress distribution
393
Name 5 factors that determine the dimensions of the post?
Root lengthRoot diameter - <1/3 diameter of rootExtention of root filling - 5mm min to maintain apical sealClinical crown heightAlveolar bone levels
394
Give an example staging for a cast post and core?
Review RCTPost space prepCrown prepReview anti-rotationCoronal finishing
395
Core impression restorations for the cast post and core?
Indirect - imps + castDirect - resin pattern
396
Comapre the indirect versus direct techniques for coring?
Indirect:- less surgery time- working imos- opposing cast- shaape of core technician determinedDirect:- increased surgery time- direct pattern- no opposing acst- core shape by operator
397
Name the 3 tools for the parapost?
Temp postImps post (smooth)Pattern post (serrated)
398
Describe the indirect technique for post creation?
Elastomeic impression (wash imps) + lab fabricationUsing smooth imps post
399
Describe the direct technique for post creation?
Colours relate to parapost diameterUsing serrated burn-out post + DuraLay
400
Describe the Nealon Incremental Technique
Lub canal with DuraLay - bead brushForce down canal to express trapped airRecord intra-radicular anti-rotation featureTrim with turbine + diamon + waterspray
401
What to do before trying in post-retained core?
Inspect and remove any casting blebs
402
Name the potential problems for metal posts and cast etal cores?
Radicul;ar fractureCoronal leakageRetriveability
403
Name 3 types of fibre posts?
CarbonGlassQuartz
404
Explain the clinical technique for fibre post placement?
Evaluate pre-Op radioDetermine post length + widthCreate post prep and anti-rotation - before refining coronal prepExtra-coronal prepEval H:W of axial wallsPost lengthFinial finishSelf-etching composite luting cement - Rely X Unicem
405
Name the disadvantages of fibre posts?
Post fractureLoss of retentionBond of composite resin to dentineBond to post
406
What will determine the success?
Amount and location of the remaining tooth structure
407
Why do we need a core?
Provide retention and resistance formRestoration of coronal tissueDurable coronal seal
408
How can we increase retention and resistance using a core?
Use of adhesive materials to bond to toothtissues (crown and core)Use of undercuts and grooves in remainingtooth tissue (core)Use of ferrule (crown)
409
How do we assess the need for a core?
1. Can the tooth provide retention for its extra-coronalrestoration without additional material being added?2. Do we need to add material that will aid resistance andretention, or do we just need to block out irregularities?3. Is there sufficient remaining tooth tissue to retain andsupport a core?4. Can a ferrule be achieved?
