14. Hard tissue anomalies Flashcards
What is enamel hypoplasia? What do the teeth look like?
- quantitative defect- enamel is deficient in quantity
- forms irregular shaped teeth
- can be thin/pitted/smaller
- normal to see yellow dentine
What is hypomineralisation? What do the teeth look like?
- qualitative defect in the enamel
- opaque/creamy white or yellow/brown discolouration
How can you classify tooth discolouration?
- congenital/acquired
- extrinsic/intrinsic
- enamel/dentine
- generalised/localised
How can trauma cause defects?
- often will cause a localised defect
- trauma in primary teeth, especially under the age of 3 years old will affect the permanent tooth’s calcification
How does radiation cause defects?
- if a child has radiation, chemotherapy or lots of hospital visits for complex medical problems especially under the age of 3, may also affect enamel formation
How does infection cause defects?
- will often cause localised defect
- if a child has caries and chronic sinus in primary tooth, it may disrupt the formation of permanent incisor enamel
What can generalised defects be?
- often symmetrical and in multiple teeth
- chronological- chronological hypoplasia is a generalised form of hypoplasia, with a characteristic
presentation of symmetrical defects with a chronological pattern, with only parts of the teeth
developing (enamel secretion) at the time of the insult affected. - non-chronological- not related to any particular time during tooth formation
What are examples of chronological generalised defects?
- malnutrition/metabolic disturbances- eg, green teeth due to deposit of biliverdin
- intoxication- tetracycline- not licensed for under 12’s
- infection
What are examples of genetic non-chronological defects?
- tooth disturbance only or in association with disease or syndrome
- eg. amelogenesis imperfecta
What is an example of non-chronological, long lasting influence of environment or disease defect?
- chronic disease
- chronic intoxication
What are extrinsic factors causing tooth discolouration?
- beverages/food
- smoking
- poor oral hygiene
- drugs
- chromogenic bacteria
- chlorhexidine gluconate mouthwash
What are intrinsic factors causing tooth discolouration?
- enamel- localised/generalised
- dentine- local/systemic
What is chromogenic bacteria and what does it cause?
- bacteria is formed as a waste product, and this is stain forming
- makes the teeth appear black
What is the treatment for chromogenic bacteria?
- brush teeth with prophy paste
- if microflora of the mouth is still the same, it may redeposit onto teeth
- remove staining, give child week course of CHX which ma alter the microflora
- most children grow out of this bacteria, especially as permanent teeth erupt
What are localised causes for enamel discolouration?
- caries
- molar-incisor hypo-mineralisation
- injury/infection of primary successor
- internal resorption
- idiopathic
What are generalised causes for enamel discolouration?
- amelogenesis imperfecta
- drugs/chemicals
- idiopathic
- systemic illness (chronological)
What is the definition of molar-incisor hypomineralisation?
- hypomineralisation of systemic origin of one to four first permanent molars frequently associated with affected incisors
- prevalence= 3.6-25%
What has to be affected in MIH?
- at least one first permanent molar has to be affected for a diagnosis of MIH
- ## the more affected the molars, the more incisors involved and the more severe the defects
Where else may defects of MIH be seen?
- second primary molars
- premolars
- second permanent molars
- tip of the canines
What are clinical features of MIH?
- in the permanent dentition
- defect seen in first molars and incisors
- soft porous chalky enamel
- opacities well demarcated
- asymmetrical in defects
What is post eruptive breakdown?
- severely affected enamel breaks down following tooth eruption, due to masticatory forces
- you get loss of the initially formed surface and variable degree of porosity of the remaining hypomineralised areas
- the loss is often associated with a pre-existing demarcated opacity
- can cause areas of exposed dentine and subsequent caries development
- seen in severe
What are the signs and symptoms of mild MIH?
- demarcated enamel opacities without enamel breakdown
- induced sensitivity to triple air but not brushing
- mild aesthetic concern
What is severe MIH?
- breakdown and caries
- spontaneous hypersensitivity and impact on function
- strong aesthetic concerns that may have socio psychological impact
What is the association between primary teeth and MIH occuring?
Association between hypomineralisation of primary second molars and MIH suggests it can be used as a predictor for MIH.
What are aetiological factors of MIH?
- ameloblasts affected at a specific stage of development
- in early maturation or late secretory stage
- unknown factors
What 2 categories can MIH be split into?
- maternal
- neo-natal
What are maternal causes for MIH?
- endocrine disturbances
- infection
- drugs
- nutritional
- haematological
- metabolic
What are neonatal causes for MIH?
- prematurity
- systemic upset-fevers/chicken pox
- antibiotics
- dioxins in breast milk
- idiopathic
- genetic mutation
What are the treatment options for MIH?
- dietary advice, OHI
- relief of pain
- careful tx planning
- orthodontic assessment
What are the treatment options for MIH in posterior teeth that are moderately affected?
- fluoride varnish
- fissure sealants- better retention with bond
- SDF can help with hypersensitivity and caries progression
- stabilisation, eg. GIC
- restoration- can be challenging due to bonding and needing good moisture control
What is the management of MIH for severely affected teeth?
- refer
- PMC
- onlays
- extractions
What do you need to be careful about in enforced extractions?
If you take one molar out, the one in opposite arch may overerupt into space, stopping the 7’s from mesialising, causing occlusal problems. May need compensating extraction.
- consider if 7 is mesio angular
- check if the 5 is locked into the roots of the E which will stop the 5 from being distally impacted if the 6 is extracted
- if only one tooth is extracted, child can wear night time retainer to prevent over eruption
What age can you use GIC till to restore MIH teeth?
6-9 years
What is the best ages to extract a MIH molar?
6-10 years to allow spontaneous space closure
What are the tx options for MIH posterior teeth from least to most severe?
- sealants
- glass ionomer
- composite
- PMC
- extractions
What toothpaste can you use for MIH?
Accasion phsosphate toothpaste- not readily available in the UK and can help in reducing sensitivity
What are the treatment options for MIH in anterior teeth?
- regional whitening
- micro-abrasion
- resin infiltration
- macro-abrasion
- composite restoration
- vital bleaching- however cannot always do this if the teeth are really sensitive
What is amelogenesis imperfecta and what teeth does it affect?
- inherited disorder characterised by abnormal enamel formation
- usually affects both primary and permanent dentition
- several different types isolated
What other tooth factors is amelogensis imperfecta associated with?
- anterior open bite
- taurodontism
- delayed eruption
How can you classify amelogensis imperfecta by phenotype?
- hypoplastic
- hypomineralised
- mixed
How can you classify amelogenesis imperfecta by inheritance pattern?
- autosomal dominant
- autosomal recessive
- x-linked
What are the genotypes involved in amelogenesis imperfecta?
MMP20 (Matrix Metalloproteinase)
Kalkerin 4
Enamelin
Amelogenin
FAM20A
FAM83H
What is the phenotype for amelogenesis imperfecta hypoplasia?
- deficient matrix
- normal calcification
What is the phenotype for amelogenesis imperfecta hypomineralisation?
- normal matrix
- poorly mineralised due to hypocalcification or hypomaturation
What does hypoplastic AI look like?
- variable clinical appearance
- deficient matrix so enamel typically thin in areas
- tooth wear does not occur as rapidly as in hypomineralised amelogenesis
How does x linked hypoplastic amelogenesis imperfecta affect males?
- enamel thin or hard
- smooth or pitted
How does x linked hypoplastic AI affect heterozygotic female?
- alternating bands of near normal enamel with bands of pitted enamel- lyonisation
What does hypocalcified amelogenesis imperfecta look like?
- enamel erupts opaque-white to brown surface
- normal amount of enamel at eruption, but soft and rapidly wears
- sensitive dentine exposed
- degree to which teeth affected not evenly distributed, often bilateral symmetry
- delayed eruption and coronal resorption
- lack of radiographic contrast between enamel and dentine
What does hypomaturation AI present like?
- normal matrix and therefore normal thickness of enamel on eruption
- poorly mineralised but less severe than hypocalcified
- enamel tends to chip and wear
What does hypomaturation/hypocalcified AI appear like on a radiograph?
- lack of differentiation between enamel and dentine- hypocalcified
- evidence of wear
- taurodont characteristics of molars
What syndrome is AI associated with where kidneys are involved?
- enamel renal syndrome
- get nephrocalcinosis
- get hypoplastic type of AI
- FAM20A gene affected
What syndrome is AI associated with where vision may be affected?
- Jalili syndrome
- get cone rod dystrophy
- autosomal recessive
What is the definition of dental fluorosis?
- imperfections of dental enamel- from white spots to severe hypoplasia- are caused by any disturbance of calcification during development
What does fluorosis look like?
- diffuse
- mottled
- often chronological
- can be due to history of excess fluoride consumption
How can vit D affect teeth?
Vit D deficiency can lead to chronological hypoplasia
What are localised causes of dentine discolouration?
- caries
- internal resorption
- metallic restorative materials
- necrotic pulp tissue
- root canal filling materials
What are generalised causes for dentine discolouration?
- bilirubin (haemolytic disease of the new born)
- congenital porphyria
- dentinogenesis imperfecta
- drugs/chemicals
What is the inheritance pattern of dentinogenesis imperfecta? What is the ratio occurence?
- 1:80000
- autosomal dominant
What gene is affected in dentinogenesis imperfecta?
- DSPP gene
- Gc locus on chromosome 4
What are the shields classification of dentinogenesis imperfecta?
- type 1- associated with osteogenesis imperfecta
- type 2- teeth only
- type 3- brandywine
What is the revised classification of DI?
- DI type 1- DI without OI, corresponds to type 2 shields
- DI type 2- corresponds to type 3 shields
How does dentinogenesis imperfecta affect teeth?
- affects both the dentitions
- teeth look dark grey or amber opalescent
- primary teeth are affected greater than permanent as the enamel shears away
- primary teeth have small pulp chambers so often no pain associated
What does Dentinogenesis imperfecta look like radiographically?
- crowns are bulbous
- roots short and thin
- pulp chambers become obliterated
What does dentinogenesis imperfecta look like histologically?
- ADJ appears flattened
- disordered dentine structure- interglobular calcifications, cellular inclusions, abnormally shaped and sized tubules
What gene is affected in osteogenesis imperfecta and what is the inheritance pattern like?
- OI is an inherited disorder of connective tissue, affecting type 1 collagen
- autosomal dominant or recessive
- mutation in COL1A1 or COL1A2
What are the characteristics of osteogenesis imperfecta?
- increased bone fragility and bone deformity
- blue sclera
- hearing loss- can also be seen in type 1
- opalescent teeth
What is type 1 dentine dysplasia?
- it is radicular
- primary and secondary teeth have normal appearance but the teeth are rootless
- looks like floating teeth on radiographs
What is type 2 dentine dysplasia?
- primary teeth- bluish/amber discolouration and total pulp obliteration
- secondary teeth- normal appearance and thistle tube pulp
- pulp stones
What are the clinical challenges associated with DI?
- appearance
- tooth wear
- abscess formation
- restorations are difficult
- root canal is difficult due to obliterated canals
- may be on bisphosphonates
What are the simple findings for AI?
- involves all the teeth
- permanent affected more
- teeth may appear taurodont on a radiograph
- often a family history
What are the simple findings for fluorosis?
- diffuse opacities which are caries resistant
- number of teeth involved depends on time of exposure
What are simple findings for molar incisor hypomineralisation?
- involves first permanent molars and incisors
- well demarcated opacities which are caries prone
- no taurodont appearance on radiograph
What does chronological hypoplasia look like?
- banding
What factors depend on the treatment you provide?
- patient concerns
- symptoms
- age
- diagnosis
- prognosis of teeth
- medical history
What are aims of treatment in the short term?
- alleviate sensitivity
- preventive regime
What are aims of treatment in the long-term?
- prevent further tooth tissue loss
- improve anterior aesthetics
- restore vertical dimension
- often require multidisciplinary input
What desensitising agents can you use for treatment?
- fluoride toothpaste/mouthwash/varnish
- desensitising toothpastes
- bonding agents
- CPP-ACP tooth mousse- promotes remineralisation
What can you advise for prevention?
- dietary advice
- use warm water when brushing to reduce sensitivity
- fluoride use
- beware of disclosing dye as it gets absorbed into pits of the enamel and is rough and rigid so can be hard to remove
- study casts to monitor wear
What are tx options for enamel discolouration?
- vital bleaching
- icon (resin infiltrant)
- microabrasion
- localised composites
- veneers (composite)
- crowns
What are tx options for dentine discolouration?
- non-vital bleaching
- inside out bleaching
- localised composite
- veneers (composite)
- crowns
What is microabrasion?
- a controlled method of removing surface enamel in order to improve discolourations that are limited to the outer enamel
What are indications for microabrasion?
- hypoplasia
- hypomineralisation
- demineralisation eg, post ortho
- idiopathic speckling
- fluorosis
- staining prior to veneer placement
- enamel surface staining, eg. turner teeth
What are advantages of microabrasion?
- conservative
- simple
- safe and reliable
- can be repeated
What microabrasion techniques are there?
- Hydrochloric acid and pumice: sodium bicarbonate
- Phosphoric acid (etch) and pumice: bristle brush
- Phosphoric acid (etch) and softlex disc
- Commercial kits (opalustre, prema)
What equipment do you need for microabrasion with hydrochloric acid and pumice technique?
- 18% hydrochloric acid
- pumice
- 2 flat plastic hand instruments or wooden sticks
- sodium bicarbonate mixed with water
- rubber dam, wedgets, floss
- prisma gloss paste and disc/point
- fluoride gel/toothpaste (clear/white)
What pastes are used in hydrochloric acid and pumice technique for microabrasion?
paste 1: sodium bicarbonate mixed with water
paste 2: half concentrated hydrochloric acid (18%) mixed with pumice
What is the technique for hydrochloric acid and pumice microabrasion?
- Apply rubber dam and then place sodium bicarbonate mixture around gingival margins of teeth exposed through rubber dam
- Apply acid/pumice mixture to stained lesion and rub in circular motion with hand instrument or wooden stick for 5 seconds
- Wash off both pastes and repeat processes- maximum 7/8 applications per visit- maximum 15 in total
Microabrasion materials note:-
Sodium bicarbonate mixture is WHITE
▪Sodium bicarbonate mixture only placed at gingival margins
Neutralises the acid so that it does not cause gingival trauma.
▪Pumice/hydrochloric acid mixture is GREY
▪Pumice/hydrochloric acid mixture only used on the tooth in small quantities for microabrasion
What is the technique for pumice and etch and bristle brush for microabrasion?
- mix pumice and etch together
- use dry dam
- use prophy cup
- apply for 30 seconds
- repeat up to 3 times
- reassess
What are the aftercare rules for microabrasion?
- no highly coloured foods for 1-2 days, eg. curry, iced lollies (as you have opened up the enamel prisms, the teeth will be like sponges so they will be more susceptible to taking a colour stain)
- there may be continued improvement in the weeks after the treatment
- occasionally there is some sensitivity afterwards which will resolve
What is macroabrasion?
Phosphoric acid and soflex discs and finishing strips
What is icon and what does it treat well?
- low viscosity resin infiltration (etch and resin system)
- white spot lesions and mild fluorosis
How does icon work?
- designed to arrest early enamel caries by blocking the diffusion paths for cariogenic acids
- has a high penetration coefficient and a high refractive index thus altering the appearance of white spot lesions (caries or hypoplasia) to blend in with the surrounding normal coloured enamel
- need to etch the tooth, then dry with alcohol, then place the resin
What 3 things are used in icon treatment?
- icon etch (15% hydrochloric acid)
- icon dry- ethanol
- icon resin
What types of bleaching techniques are there?
- vital bleaching- chairside
- vital bleaching- fitted tray
- non-vital walking bleaching
- non-vital inside out bleaching
What is the rules for bleaching?
From 31/10/12, UK dentists can supply bleaching products to patients that contain/release 6% hydrogen peroxide (The Cosmetic Products (Safety) (Amendment) Regulations 2012)
A good technique that is the least destructive to the tooth (10% carbamide peroxide = 3.6% hydrogen peroxide)
Photos and written consent advised
Can be sensitive in children (eg. not tolerated by MIH
cases); not advised in children still with primary teeth
“Not to be used on a person under 18 years of age.”
What is the use of bleaching in people under 18?
Following campaigning from professional organisations (eg. British Society of Paediatric Dentistry), the GDC released a position statement regarding tooth whitening (2014)
“Products containing or releasing between 0.1% and 6% hydrogen peroxide cannot be used on any person under 18 years of age, except where such use is intended wholly for purpose of treating or preventing disease”
This has been interpreted by the BSPD and others to mean that one may use bleaching products for the management of disease (eg. discolouration post dental trauma) but not to enhance the appearance of otherwise ‘normal’ teeth in the under-18s
What is the method for vital at home bleaching?
Take impressions for bleaching trays
– do not need to be spaced; no reservoirs needed;
trimmed around gingival margins Take pre-operative
– photos/shade;
– consent
Fit trays and provide with bleaching gel
(10% carbamide
peroxide gel); wear and care advice
Review after 2 weeks
Continue bleaching with regular reviews till satisfied with
outcome
What is the method for non-vital (walking) bleaching?
Take impressions for bleaching trays
– do not need to be spaced; no reservoirs needed;
trimmed around gingival margins Take pre-operative
– photos/shade;
– consent
Fit trays and provide with bleaching gel
(10% carbamide
peroxide gel); wear and care advice
Review after 2 weeks
Continue bleaching with regular reviews till satisfied with outcome
What are the tx options for posterior teeth?
Accept and monitor
Temporary glass ionomer / compomer restorations / FS Composite restorations
Stainless steel crowns
Onlays
Indirect crowns-not suitable for young patients
Extraction
What are the factors to consider for posterior teeth treatment?
- sensitivity
- tooth wear
- aesthetics less of a concern posteriorly
