Dental Equipment - Intraorals Flashcards
What is periapical radiography?
Periapical x-ray showed the whole truth – from the crown to beyond the root where the tooth attaches into the jaw (alveolar ridges) - provides detailed info
Intraoral techniques designed to show individual teeth and the tissues around the apices
– each image usually shows 2 to 4 teeth
Describe the anatomy of the typical molar tooth:
The tooth can be divided into the Crown and the root (Apex)
The cross-section of the tooth shows for regions – the enamel, the Dentine, pulp and the cementum
The enamel is a part of the tooth mainly above the gum and consist mainly of calcium phosphate which is very hard
Anatomy features seen on the radiograph?
Periodontal ligaments space
Laminar dura
Trabecular pattern
How many images are required for a complete survey of an adult?
Normally 14
How is a dental abscess formed and what does it lead to?
I dental abscess is caused by infection either entering the pulp cavity – through a crack or the socket – through infection of the gums
This may lead to the formation of puss in the infected area
How does a dental abscess present on a radiographic image?
The dental abscess can be seen as an area of radiolucency - normally around the apex of the tooth
This can be obvious or subtle
What are the indications for periapical radiography?
Detection of a pickle infection/information
Assessment of Perio dental status
After trauma teeth and associated alveolar bone
Assessment of present/position of an erupted teeth
Assessment of loot morphology player to extraction
Pre-operative assessment and post-operative appraisal of apical surgery
Details evaluation of a pickle cysts and other lesions within the alveolar bone
Evaluation of implants post operatively

What is the ideal positioning for intra oral examinations?
The tooth under investigation an image receptor in contact or as close together as possible
- Tooth an image Receptor parallel to avoid distortion
- Image receptor position: long access vertical for incisors and canines
- Long axis horizontal for premolars and molars
- Sufficient area beyond apices to record apical tissues
X-ray tube position such that central Ray perpendicular to an image receptor
Positioning must be reproducible
What is a paralleling technique?
Image receptor is placed in a holder and positioned in the mouth parallel to the long axis of the tooth under investigation
The central ray Is positioned to be at right angles to both the tooth and the image Receptor
By using a holder with a fixed image receptor and x-ray tube positions that technique is reproducible

What difficulties Can paralleling technique come across?
The anatomy of the palate and shape of the dental arches make positioning of the image receptor difficult – especially in children
What is the construction of image receptor holders?
Three basic components:
Holder for image receptor – keeps it parallel to teeth and stops offending
Byte Block
X-ray beam aiming device
What determines the holder design used when taking an image?
Depends of the tooth is:
Anterior or posterior
In mandible or maxilla – lower or upper
Right or left side of jaw
(Can be colour-coded to Make identifying holders easier)
What are the two types of image receptor holder?
Digital or film packet
Go through the process of technique and care when taking an intra oral image?
Three point ID check
Remove any jewellery or artefacts – including dentures and glasses
Patient should be sitting in a chair with their head/next supported, and a close or plain horizontal
Explain the procedure
Welding gloves please see image of sceptre into the holder
Holder/image receptor should be placed personally into the mouth
Cotton wool rolls can be used for patient comfort and ease of positioning
Holder positioned such that teeth under investigation touching bite block
Patient asked to bike gently together on block to stabilise position of holder
Locator ring moved down indicator rod until just touching patients face – correct SID
X-ray tube centred to locator ring – correct horizontal/vertical tube angles: correct SID
Carry out examination quickly to minimise patient discomfort
Infection control in intraoral imaging?
How is intra oral imaging adapted for children and disabled patients?
Smaller films which can be used for small amounts
It may be necessary to ask for assistance (usually a relative) to hold the image of receptor and provide reassurance
UK guidelines state:
Only radiographic investigations are appropriate to the limitations imposed by the patient’s age, cooperation or disability should be attempted
Radiation protection in intra oral technique?
Lead rubber protection
Are necessary to use lead Robert protection in dental radiography
Well done equipment and technique Mean that this is a very low and there is deemed a greater risk of artefact – therefore repeat exposures – caused by the lead rubber protection of used
Why is the bisecting angle technique not used very often and what was the solution ?
Virtually obsolete, due to difficulty getting connect film/tube angulation which resulted in distorted images
Solutions was to use holders plus a guide for two regulation – paralleling technique
What is the principal/technique of bisecting angle?
Image of receptor placed as close to tooth under investigation as possible
Angle formed between long axis of tooth and long axis of image receptor is assessed and mentally bisected
Central ray directed at right angle to this bisecting line and aimed through tooth Apex
Receptor/film packet positioned Impatience mouth
Patient asked to gently support this in position by placing their finger behind it
Radiographer phone visually assesses the required angulation and positions of tube accordingly

Take me killers of bisecting angle technique?
If the central day is angle to steeply – less than 90° – the image of the tooth is a foreshortened
If the central day is angle to shallow – more than 90° – then the image of the tooth is in elongated and there is a danger that the apices are missed
What is the bitewing image meant show?
Individual images designed to show the count of the premolar and molar teeth
Ideally they should show no overlap of the surfaces of the teeth
What are the indications For a bitewing image?
Detection of caries
monitoring of the progression of caries
Assessment of existing installations – feelings and crowns
Assessment of the Periodontal status
 what is the technique for a bite wing images?
Image receptor position centrally within holder; upper and lower edges parallel to bite block
Posterior teeth at image receptor in contact – or as close as possible
Posterior teeth and image receptor must be parallel
In a horizontal plane central ray should be a right angles to teeth and image receptor must be parallel
In vertical plane central Ray should be angled 5 to 8° cauded
Positioning must be reproducible
What are the two types of occlusal imaging?
Maxillary occlusals:
Upper standard occlusal – anterior
Upper oblique occlusal
Mandibular occlusals:
Lower 90° occlusal – true occlusal
Lower 45° occlusal – lower or standard occlusal
What are the Anterior (upper standard) occlusal indications?
Periapical assessment of upper anterior teeth – especially children also adults unable to tolerate periapical holders
Detect presence and position of uneruprted/supernumerary teeth – especially canines
Evaluation of size and extent of lesions – cyst/tumour
Assessment of fracture of anterior teeth and Alveolar bone
What is the technique for the anterior (upper standard) occlusal?
Patience it with head supported and occlusal plane horizontal – parallel to floor
Image receptor place to mouth – portrait for children; landscape for adults – as far is back as possible and patient asked to bite Down gently to keep it in place
X-ray tube positioned above patient in midline and centrally directed through the bridge of nose at angle of 65 to 70° to image receptor
What are the lower (lower standard) occlusal indications?
Taken to show the lower anterior teeth and anterior part of mandible
Main clinical indications:
Periapical assessment of Lawrence Heisers especially in patients who cannot tolerate periapical holders
Valuation of size an extent of reasons – cyst/tumour in anterior part of mandible

What is the technique for the lower (lower standard) occlusal?
Patience with head supported and occlusal plane horizontal – parallel to the floor
Image receptor place to mouth, portrait, tubeside down, as far back as possible, and patient asked about Down gently to keep it in place
X-ray to position the midline, and central day directed through point of June, at angle of 45° to interceptor
Lower 90° occlusal, true occlusal – often used to detect salivary calculi and projection routinely forms part of preliminary image series prior to submandibular sialogram
