2020 Flashcards
List four problems that can occur when instrumenting a tooth with curved roots using only stainless steel ISO handfiles? and give reasons for each of the problems?
- Ledges - internal transportation of the canal due to working short of the working length and due to less flexibility of file
- Perforation - excessive force is applied when using the instrument
- Apical Zipping - due to the tendency of the instrument to straighten in a curved canal
- Blockage of the canal - dentine debris getting packed in the apical portion of the root
Describe the process of canal shaping and cleansing (not obturation) using ProTaper Universal instrumentation of root canals. Assume that straight line access has been achieved and working length has been determined with a size 10 stainless steel hand file. Your apical finishing size should be 0.25mm
- Assuming that dental dam has been placed and EWL determined and straight line access is achieved
- Size 15-K file to enlarge the glide path to facilitate instrumentation
- Use S1 to 2/3 of working length
- Coronal flaring using Sx file to prepare the coronal third to 2/3 of EWL
- Take radiograph to determine CWL
- Use size 10 and 15 K-files for patency to CWL
- Use S1 , S2 , F1 , F2 in order to correct working length to prepare the apical third of the canal using balanced force
- Irrigate with sodium hypochlorite between each file to flush out debris
- After preparation the irrigation potocol is 17% EDTA for 1 minute then 3% of NaOCl for 10 minutes injecting slowly using thumb
With regards to “non-Y2 amalgam”
Give 2 advantages in terms of performance of a non Y2 amalgam?
- less creep
- Higher mechanical strength
- More corrosion resistant
How does the manufacturer reduce Y2 from the structure of amalgam?
Addition of Silver copper particles which reacts with silver tin particles , making tin less available for the y2 production
With regard to zinc free amalgam , why was it necessary for manufacturers to add zinc to amalgam?
Acts as a scavenger molecule which oxidises rather than the other consistuents
What effect could occur in a freshly placed amalgam restoration as a result of the presence of zinc in the amalgam alloy?
- Delayed expansion as a result of contamination with moisture
Explain the mechanism of this effect ( slag formation)
Zinc can react with saliva or blood to form ZnO and produce hydrogen gas
* hydrogen increases pressure which may cause the restoration to rise leading to a higher chance of deformation under occlusal load and cause trauma to pulp
What is the main symptoms that the patient feels when slag forms from zinc in amalgam?
- Pain
A 33-year-old patient presents with a discoloured upper left central incisor tooth. The patient has no caries or restorations of any kind in any teeth and is fit and healthy. The discolouration, first noticed two years ago, has been getting steadily worse. There are no symptoms, and the patient is concerned with the appearance. He recalls a blow to the tooth when playing sport a few years previously.
Determine how you would determine the aetiology of the discolouration?
- Full history of trauma
- TTP
- Radiographs ( Periapical of 22)
- Sensibility testing of 22 and 21
A 33-year-old patient presents with a discoloured upper left central incisor tooth. The patient has no caries or restorations of any kind in any teeth and is fit and healthy. The discolouration, first noticed two years ago, has been getting steadily worse. There are no symptoms, and the patient is concerned with the appearance. He recalls a blow to the tooth when playing sport a few years previously.
State 3 sequale of dental trauma that may influence your treatment planning for this tooth ?
- Pulp health
- Mobility - excessive, ankylosis
- Root resorption
A 33-year-old patient presents with a discoloured upper left central incisor tooth. The patient has no caries or restorations of any kind in any teeth and is fit and healthy. The discolouration, first noticed two years ago, has been getting steadily worse. There are no symptoms, and the patient is concerned with the appearance. He recalls a blow to the tooth when playing sport a few years previously.
List and describe two restorative procedures you may carry out to improve the aesthetics of this tooth?
- External vital bleaching using hydrogen peroxide which is applied to the tooth after placing dental dam and petroleum jelly on the gingivae to protect it , which can be applied for up to 5 times until desired colour is achieved
- Porcelain veneer - by taking impressions of the tooth with or without preparing it depending on the operator judgement and sending it to the lab for the fabrication of a veneer which is then bonded to the tooth using a composite resin luting cement with silane coupling agent
Describe 2 patterns of bone loss evident in this radiograph?
- Horizontal and vertical
What explains the development of bone loss on the mesial aspect of the lower right second premolar?
- Presence of plaque accumulation (scalloping) in the distal aspect of the tooth , the canal curvature may have acted as a plaque trap
How can interproximal bone defects be classified in general
According the walls involved - 1,2,3 wall defects
Following hygiene phase therapy this patient’s oral hygiene was excellent but pockets of >6mm persisted in the lower right quadrant. Open flap debridement was performed
What feature of this patient’s disease which is on the radiograph is most likely to limit the success of this treatment and why?
Fucration involvement due to bone loss making access for cleaning difficult leading to poor prognosis of tooth
List the best possible outcome clinical and radiographic outcomes for this type of treatment in terms of the healed situation?
- Pocket depths less than 4mm
- Bleeding on probing less than 10%
- Plaque scores less than 15%
Give two other treatment options for managing the lower right second molar ?
- Guided tissue regeneration
- Tunneling - Furcation
A patient comes in with a fractured MCC crown with core fractured inside the crown, patient has no pain and the tooth is not root treated
What 4 features of the remaining tooth tissue of the central incisor might indicate wither it can be successfuly restored or not?
- Quality of tooth tissue remaining
- Amount of tooth tissue remaining (ferrule should be 1.5 in height and width)
- Type of fracture (if the pulp is involved)
- Mobility and health of periodontal tissue
A middle-aged gentleman attended your surgery with the metal ceramic crown from his upper right central incisor in his hand. He has no pain. You notice that the dentine core has fractured off inside the crown. There is no history of previous root canal therapy.
The tooth is restorable , list and describe 3 ways in which the space can be restored in the short term ?
- Rebond Fractured MCC crown using a temporary cement
- Overdenture with a single acrylic tooth- on the remaining tooth structure
- Vacuum formed splint with the fractured MCC crown or with an acrylic tooth crown
- A temporary crown using a prefabricated tooth matrix done chair-side using temporary resin material
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
What supporting components would you use? list the type and surface?
- 34 mesial rest - part of RPI system
- 44 distal rest
- 47 mesial rest
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
List the retentive components that you would use, indicate component name , FDI and position
- 34 - gingivally approaching I-bar clasp with guide plate ( Part of RPI system)
- 44 - Gingivally approaching I-bar clasp
- 47 - Circumferential ring clasp
- 43 - mesial rest for indirect retention
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
Name the major connectors and state the reasons for your choice including the choice of material
- Lingual bar - CoCr - as it can provide good clearance for the patient to clean and is more comfortable in the mouth ( it need 8mm clearance on the lingual aspect)
A patient has the following missing teeth: 38, 37, 36, 35, 45 and 46. You decide to provide a definitive removable partial denture. The patient has a well maintained mouth with no active disease and you can assume has suitable survey lines.
Which feature of your design would provide indirect retention?
cingulum rest on 43
Major connector
The illustration is of an upper edentulous ridge , please identify the anatomical landmarks indicated ?
A - incisive papilla
B - Maxillary tuberosity
C - Palatine fovea
In terms of complete dentures what is meant by stability?
Resistance of the denture to lateral movement
In terms of complete dentures what is meant by retention?
Resistance of the denture to vertical displacement ( away from the gingivae)
How do you achieve adequate retention in a conventional complete upper denture?
- Ensure denture have a good peripheral seal insuring good extensions
- Accurate post dam placement
- Maximise palatal coverage of the denture base
- Ensure to have a balanced occlusion with opposing arch
In terms of biometric principles where are denture teeth located on ?
- Upper - buccal to the alveolar ridge
- Lower - on the alveolar ridge
A fit and healthy 32 year-old patient requires surgical removal of his lower left wisdom tooth. He is very anxious about the surgery and has opted to have the treatment carried out under intravenous sedation.
Why is written consent required in advance of the treatment day in sedation?
- So the patient can take their time to consider the information provided and allow a timeframe for the patient to decide thoroughly
A fit and healthy 32 year-old patient requires surgical removal of his lower left wisdom tooth. He is very anxious about the surgery and has opted to have the treatment carried out under intravenous sedation.
What drug would a UK trained dentist select to sedate the patient intravenously? What preparation should be used?
- Midazolam 5mg/5ml - 2mg bolus titrated in 1mg increments every minute
A fit and healthy 32 year-old patient requires surgical removal of his lower left wisdom tooth. He is very anxious about the surgery and has opted to have the treatment carried out under intravenous sedation.
What vital signs would you monitor and record before, during and after procedure?
- Heart rate
- Blood pressure
- Oxygen saturation
- BMI (height and weight)
What is the antidote for midazolam?
Flumazenil 500mcg in 5 ml
A fit and healthy 32 year-old patient requires surgical removal of his lower left wisdom tooth. He is very anxious about the surgery and has opted to have the treatment carried out under intravenous sedation.
List 3 instructions that the patient should follow post sedation for a minimum of 12 hours after he is discharged from your care ?
- Do not make important decision
- Do not drive or operate heavy machinery
- Rest
Your patient has sustained a displaced fracture of the right body of the mandible.
Other than pain, bruising and swelling , name 6 clinical signs or symptoms commonly described in such injury?
- Bleeding
- Facial asymmetry
- Occlusal derangement
- Trismus
- Mobile teeth
- Numbness in the chin and lower lips on the side of injury
Your patient has sustained a displaced fracture of the right body of the mandible.
- What are two radiographic views appropriate to help in establishing the diagnosis of a mandibular fracture?
- OPT
- PA mandible
Your patient has sustained a displaced fracture of the right body of the mandible.
List three factors that may cause displacement of the fracture?
- Direction of fracture line
- Magnitude of force applied
- Attachment of muscles in the fracture site
List 3 treatment options for a fractured mandible?
- Leave and monitor
- Open reduction with internal fixation
- Intermaxillary fixation (IMF)
A 35-year-old male presents with pain, swelling and pus discharge around a partially erupted lower right wisdom tooth. He feels slightly unwell and has some mild facial swelling.
Describe 6 features you would specifically consider, relating to the patient’s history, extraoral examination or investigations?
- Is the airway compromised
- Palpate swelling for tenderness, temprature
- Ask patient of when did the swelling start and has it changes in size
- Ask the patient if this pain happened before and frequency
- Check mouth opening - note if limited
- When did he start feeling unwell
- Pain history
- Take OPT
- Source of infection and check opposing tooth
- If the patient is allergic to antibiotics
A 35-year-old male presents with pain, swelling and pus discharge around a partially erupted lower right wisdom tooth. He feels slightly unwell and has some mild facial swelling.
What is the appropriate immediate management of this patient?
- Check if airway is compromised - if compromised refer for emergency management
- Reassure patient and gain consent
- Incise and drain abscess under LA
- Prescribe analgesia
- Prescribe antibiotics as patient with systemic symptoms
- Advise patient on CHX mouthwash
- Consider extraction of wisdom tooth if recurrent pericoronitis
- Adjust opposing occlusion to relieve area if trauma is from opposing tooth
What are the two main branches at risk of damage during removal lower wisdom teeth and which structures would be affected in the event of such damage?
- Lingual nerve - sensation of the anterior 2/3 of tongue
- Inferior alveolar nerve - lower lips and chin
Give a differential diagnosis of this lesion?
- Condyloma acuminata
- Squamous cell carcinoma
- Squamous cell papilloma
If you suspected that the lesion is malignant , name three histological features that need to be identified in the biopsy?
- Mitotic activity
- Cellular and Neuclear atypia
- Architectural changes in the epithelium such as dysplasia
List 3 different clinical presentation of oral squamous cell carcinoma?
- Exophytic lesion
- Ulceration
- Leukoplakia or Erythroplakia
The pathology report comes back stating that the lesion is benign , what do you think have cause this growth to appear? and how you would confirm this ? how would you confirm this?
HPV - by detecting the HPV DNA through a PCR test
A patient present with evidence of bony expansion of their maxilla
The patient is elderly and has a high alkaline phosphate level
What condition might have caused this?
Paget’s disease
A patient present with evidence of bony expansion of their maxilla
The patient has a raised serum calcium level
What condition might have caused this?
Hyperparathyroidism
A patient present with evidence of bony expansion of their maxilla
The patient is 15 years old and has bilateral maxillary expansion
What condition might have caused this?
Cherubism
A patient present with evidence of bony expansion of their maxilla
Radiography shows a radiolucency with generalised loss of lamina dura
What condition might have caused this?
Paget’s disease
A patient present with evidence of bony expansion of their maxilla
The patient has pigmented spots on their skin and has precocious puberty
What condition might have caused this?
Albright’s syndrome
A patient presents with pain in their face. Which condition would be the most likely diagnosis in the following scenarios
- middle-ages female patient with constant burning sensation affecting the palate and tongue, with erythema of the mucosa
- male patient with a recent onset dull throbbing pain over the maxilla worsened by bending over to tie his shoes
- Young, adult female patient with episodic unilateral peri-orbital pain lasting 20 minutes with nasal congestion , the pain being brought on by shaking of the head
- Elderly female patient with sharp, shooting pain over the right cheek brought on by eating and associated with lacrimation
- Elderly female patient with unilateral , throbbing temporal pain and loss of muscular power around the shoulders
- burning mouth syndrome
- maxillary sinusitis
- chronic paroxysmal hemicranias
- trigeminal neuralgia
- temporal arteritis
A patient is referred to the Oral Medicine clinic for evaluation of her dry mouth
Sjogren’s syndrome can be part of the spectrum of autoimmune characteristic features are often seen in salivary gland biopsies in this condition, from which part of the orofacial structures is it the most common to take a salivary gland biopsy as part of the investigation of suspected Sjogren’s?
Labial gland
List two features on the histological examination of a labial gland biopsy that would be compatible with Sjogren’s syndrome?
- Collection of more than 50 lymphocytes around a duct - lymphocytic foci
- Acinar atrophy
Focal swelling in the major salivary glands is usually associated with salivary malignancy. What feature in relation to a parotid gland lump may suggest a malignant rather than a benign tumour?
- Asymmetrical
- Causes obstruction
- Causes pain and facial palsey
What is the most common salivary gland tumour in the parotid gland?
Pleomorphic adenoma
What is the most common salivary gland tumour in the salivary glands of the upper lip?
Adenoid cystic carcinoma
What is the most common salivary gland tumour of the salivary glands in the soft palate?
Mucoepidermoid carcinoma
List two ways that the skeletal base relationship may be assessed clinically in the anteroposterior plane.
- Visually with the patient Frankfort plane parallel to the floor
- Palpate skeletal bases using Kettles method
Cephalometric analysis reveals that a patient has an ANB angle of 8 degrees. What does this suggest about their skeletal pattern?
The maxilla is more than 3mm anterior to the mandible meaning they have moderate skeletal class 2
List two ways that the skeletal pattern can be assessed clinically in the vertical plane?
- FMPA angle
- Upper anterior face height to lower anterior face height
What is meant by a class III incisor relationship?
- The mandibular incisors lie anterior to the cingulum plateau of the maxillary incisors
- with reduced or reversed overjet
What is a balancing extraction and why might you consider a balancing extraction?
- When the same tooth on the opposite side of the same arch is also extracted , used to prevent midline shift
A child presents with the upper left permanent central incisor in crossbite , when is the ideal time to treat this type of malocclusion?
As soon as the problem has been detected
This is an extract from an advertisement in a dental magazine
State the research question using the PICO framework?
Population - smokers
Intervention - shiny sheen
Comparison - brand market leader
Outcomes - preventing tooth staining
What kind of study is this?
Randomised control trial
What two steps have been taken to minimise bias in this study?
- Blinding
- Random allocation
Is there sufficient evidence that Shiny Sheen is effective at preventing tooth staining in the population of smokers? and why?
NO , the confidence interval overlaps 1 which means that the results are statistically insignificant
List four additional pieces of information you would wish to know before drawing firm conclusions on whether or not you would consider recommending Shiny Sheen as a smokers’ toothpaste.
- Information about smoking habit frequency and duration
- Oral health of participants at baseline
- Information of compliance of participants with using the intervention
- Information on any side effects the participants experienced due to the intervention
- Any follow up input from participants after the 1 month period and participant satisfaction
A 27-year-old male with congenitally absent maxillary lateral incisors attends your practice. He has been wearing an upper acrylic denture to replace his missing teeth for the past 10-years and now wishes to discuss alternative treatment options.
After discussion with the patient, you decide to restore the spaces with bridgework.
Which type of bridgework design would be most suitable for this case? and which teeth would you choose as an abutement?
Cantilever resin retained bridge , tooth 11 and 21
Patient attends with severe toothache associated with tooth 37 which is tender to percussion
What 3 questions would you ask this patient that may lead you to a diagnosis of the cause?
- When did the pain start? and decribe the character of it?
- Is there any factors that helped relieve the pain or make it worse? and how? Did analgesics work?
- Are you stressed?
From the photograph and radiograph, list 3 findings that are relevant to the patient symptoms of pain from 37?
- Secondary caries under amalgam restoration on 37 (distal)
- Fractured distobuccal cusp on 37
- Defective restoration margins on MOD amalgam on the 37 with discolouration
What is the apical diagnosis of tooth 37 ? TTP positive and pain
Symptomatic Apical periodontitis
A 53 year old female patient requests new complete dentures. She has worn the present set for 15 years and they are now becoming loose. Her medical history is clear. The photograph shows her upper arch with the dentures removed. The palatal denture-bearing mucosa is red.
Which organism is most likely to have proliferated in the denture bearing area?
Candida albicans
A 53 year old female patient requests new complete dentures. She has worn the present set for 15 years and they are now becoming loose. Her medical history is clear. The photograph shows her upper arch with the dentures removed. The palatal denture-bearing mucosa is red.
Give 3 most likely contributing factors to this infection?
- Poor denture hygiene
- ill fitting denture
- Wearing the denture all the time and not taking them off at night
What might have happened to the occluding surfaces of the denture teeth after 15 years (1 mark) and can anything be done to the existing dentures to rectify this in the short term (1 mark)?
Wear , autopolymerising resin added to build the teeth back
On examination there were creamy-white plaques on the oral mucosa, which could be easily removed to leave an erythematous base.
What is the most likely clinical diagnosis?
Oral pseudomembranous candidosis
two conditions which might be associated with development of pseudomembranous candidosis
- Diabetes (poorly controlled)
- HIV (immunocompromised)
Why does herpes simplex becomes recurrent?
- Due to its ability to establish latency in the host after initial infection at young age , where it stays dormant in the trigeminal ganglion , reactivation to the virus happens due to triggers such as stress and immune suppression causing the virus to replicate and lead the clinical presentation
A fit, healthy 24-year-old female presents with recurrent oral ulceration affecting the buccal mucosa which arise in crops of 2 - 10 and last for 10 days before healing without scarring. She has always had the occasional mouth ulcer but for the past three months she is getting several ulcers at a time with only a short break between one episode and the next.
What is the clinical diagnosis?
Recurrent apthous stomatitis
What is the likely diagnosis based on these blood tests?
- Microcytic anaemia
What type of resorption is affecting tooth 11? What makes it progress and what is the treatment plan?
- External inflammatory root resorption
- Infection of bacteria due to pulp necrosis following trauma makes it progress
- Remove cause , root canal treatment
